WO2025098942A1 - Nonwoven fabric and process for forming the same - Google Patents
Nonwoven fabric and process for forming the same Download PDFInfo
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- WO2025098942A1 WO2025098942A1 PCT/EP2024/081095 EP2024081095W WO2025098942A1 WO 2025098942 A1 WO2025098942 A1 WO 2025098942A1 EP 2024081095 W EP2024081095 W EP 2024081095W WO 2025098942 A1 WO2025098942 A1 WO 2025098942A1
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- polylactic acid
- fibers
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- nonwoven fabric
- sheath component
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/005—Synthetic yarns or filaments
- D04H3/009—Condensation or reaction polymers
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
- D04H3/14—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic yarns or filaments produced by welding
- D04H3/147—Composite yarns or filaments
Definitions
- the present invention relates to a nonwoven fabric, a process for preparing the nonwoven fabric, and an article comprising the non-woven fabric.
- Nonwoven fabrics are used in a variety of applications such as garments, disposable medical products, diapers, personal hygiene products, among others. New products being developed for these applications have demanding performance requirements, including comfort, conformability to the body, freedom of body movement, good softness and drape, adequate tensile strength and durability, and resistance to surface abrasion, pilling or fuzzing. Accordingly, the nonwoven fabrics which are used in these types of products must be engineered to meet these performance requirements.
- Polylactic acid or polylactide-based polymers provide a cost-effective path to sustainable content spunbond nonwovens that can be readily converted into consumer products.
- Polylactic acid (PLA) is made from vegetable renewable raw materials such as sugars from food crops such as maize, sugar beet, sugar cane and wheat or cellulose.
- Polylactic acid has the advantage that it is compostable and will dissolve into carbon dioxide, biomass and water. In addition, polylactic acid is recyclable. Polylactic acid is mainly formed from the monomers lactic acid, and the cyclic di-ester, lactide. Polylactic acid is usually formed by means of ring-opening polymerization of lactide using a metal catalyst such as for instance tin octoate. Another process to form polylactic acid involves the direct condensation of lactic acid monomers. To fully capture the cost-effective benefits of PLA-based consumer products, PLA must be convertible into nonwovens and then into the final consumer product at very high speeds with minimal waste.
- nonwovens have been developed with fibers having a sheath/core bicomponent structure in which the PLA is present in the core, and a synthetic polymer, such as polypropylene, is in the sheath.
- a synthetic polymer such as polypropylene
- U.S. Pat. No. 6,506,873 An example of such a nonwoven fabric is described in U.S. Pat. No. 6,506,873.
- the presence of such a synthetic polymer in the sheath provides the necessary properties for commercial production of nonwovens comprising PLA at high speeds.
- this solution does not extend far enough because the industry (and its consumers) are seeking for full sustainability, and thus preferably for nonwovens being made as much as possible of PLA.
- PLA polybutylene succinate
- the present invention relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
- the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2)
- the present invention provides nonwoven fabrics, as well as sustainable composites including the present nonwoven fabrics, and sustainable articles including the present nonwoven fabrics.
- sustainable articles include PLA-based hygiene articles such as diapers, containers and covers for use in respect of plants and/or agriculture applications, packaging materials, bags and pouches.
- the core component is suitably present in an amount in the range of from 50-90 wt% and the sheath component is suitably present in an amount of from 10-50 wt%, both based on total weight of the fibers.
- the core component is present in an amount in the range of from 60-80 wt% and the sheath component is present in an amount of from 20-40 wt%, both based on total weight of the fibers.
- the core component is present in an amount in the range of from 65- 75 wt% and the sheath component is present in an amount of from 25-35 wt%, both based on total weight of the fibers.
- the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2).
- the present invention relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
- the core component comprises a first polylactic acid (PLA1)
- the sheath component comprises a second polylactic acid (PLA2)
- the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid.
- At least the sheath component comprises a calcium carbonate, whereby the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, preferably 5-25 wt%, more preferably 5-20 wt%, and most preferably up to 20 wt%, and most preferably 7.5-20 wt%, based on the total weight of the sheath component.
- the core and sheath components are extruded from separate extruders, and the two fibers components are preferably arranged in substantially constantly positioned distinct zones across the cross-section of the fibers.
- nonwoven As used herein, the terms “nonwoven,” “nonwoven web” and “nonwoven fabric” refer to a structure or a web of material which has been formed without use of weaving or knitting processes to produce a structure of individual fibers or threads which are intermeshed, but not in an identifiable, repeating manner. Nonwoven webs have been, in the past, formed by a variety of conventional processes such as, for example, meltblown processes, spunbond processes, and staple fibers carding processes.
- machine direction refers to the direction of travel of the nonwoven web during manufacturing.
- cross direction refers to a direction that is perpendicular to the machine direction and extends laterally across the width of the nonwoven web.
- spunbond refers to a process involving extruding a molten thermoplastic material as fibers from a plurality of fine, usually circular, capillaries of a spinneret, with the fibers then being attenuated and drawn mechanically or pneumatically.
- the spunbond bicomponent fibers to be used in accordance with the present invention are continuous fibers.
- spunbond continuous bicomponent fibers are much longer than staple fibers.
- the spunbond continuous bicomponent fibers are deposited on a collecting surface to form a web of randomly arranged continuous fibers which can thereafter be bonded together to form a coherent nonwoven fabric.
- the production of spunbond non-woven webs is illustrated in patents such as, for example, U.S. Pat. Nos. 3,338,992; 3,692,613, 3,802,817; 4,405,297 and 5,665,300.
- these spunbond processes include extruding the fibers from a spinneret, quenching the continuous fibers with a flow of air to hasten the solidification of the molten fibers, attenuating the fibers by applying a draw tension, either by pneumatically entraining the fibers in an air stream or mechanically by wrapping them around mechanical draw rolls, depositing the drawn fibers onto a collection surface to form a web, and bonding the web of loose fibers into a nonwoven fabric.
- the bonding can be any thermal or chemical bonding treatment, such a through-air bonding or thermal point bonding.
- thermal point bonding involves passing a material such as one or more webs of fibers to be bonded between a heated calender roll and an anvil roll.
- the calender roll is typically patterned so that the fabric is bonded in discrete point bond sites rather than being bonded across its entire surface.
- the term “through-air bonding” involves a process in which hot air is used to fuse the fibers at the surface of a nonwoven web and optionally internally within the nonwoven web.
- the hot air can either be blown through the web in an oven or sucked through the web as it passes over a porous drum as a vacuum is developed.
- the temperature of the hot air may be high enough to melt and/or fuse the sheath component of the continuous bicomponent fibers while not melting the core component of the continuous bicomponent fibers.
- the hot air may also initiate crimping of continuous bicomponent fibers.
- the nonwoven fabrics in accordance with the present invention are substantially free of synthetic polymer components, such as petroleum-based materials and polymers.
- Both the core and sheath components of the continuous bicomponent fibers according to the present invention may comprise one or more additional additives.
- the additive may comprise at least a colorant, a softening agent, a slip agent, an antistatic agent, a lubricant, a hydrophilic agent, a liquid repellent, an antioxidant, and the like, or any combination thereof.
- the core component and/or sheath component may contain another PLA polymer.
- the PLA1 or blend of PLA1 with the another PLA in the core component has preferably a higher melting temperature than the PLA2 or blend of PLA2 with the another PLA in the sheath component.
- the core component of the continuous bicomponent fibers comprises only one type of PLA, viz. the first polylactic acid (PLA1).
- the sheath component of the spunbond fibers comprises only one type of PLA, viz. the second polylactic acid (PLA2), which may be the same polylactic acid as the first polylactic acid (PLA1) or may be a different polylactic acid.
- the first polylactic acid (PLA1) and the second polylactic acid (PLA2) to be used to be used in accordance with the present invention have suitably a weight average molecular weight in the range of from 100,000-300,000 Dalton, preferably in the range of from 150,000-250,000 Dalton.
- first polylactic acid (PLA1) and the second polylactic acid (PLA2) to be used in accordance with the present invention may have different weight percentages of D isomer.
- the second polylactic acid (PLA2) in the sheath component may have a weight percent of D isomer up to and including 10 % by weight
- the first polylactic acid (PLA1) in the core component may have a weight percent of D isomer in the range of from 0.2-2 % by weight.
- the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers.
- the present invention relates also to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the sheath component comprises in addition at least one polybutylene succinate- based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers, wherein the nonwoven web has a side with a surface having a bonded area, and wherein
- the present invention provides a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein at least the sheath component comprises in addition at least one polybutylene succinate- based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the core component comprises
- the present invention provides to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the sheath component comprises in addition at least one polybutylene succinate- based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein
- the present invention provides a nonwoven fabric which comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein at least the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of
- the present invention provides a nonwoven fabric which comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein at least the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers
- the present invention provides a nonwoven fabric which comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein at least the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers
- the at least one secondary alkane sulfonate is suitably present in an amount ranging from about 0.01 to 2.5 wt%, based on the total weight of the fibers.
- the at least one secondary alkane sulfonate is preferably present in at least the sheath component of the continuous bicomponent fibers.
- the additional use in the sheath component of a polybutylene succinate-based polyester has the advantage that the nonwoven fabric exhibits a considerable increase in tensile strength and elongation in both the machine direction and the cross direction in comparison to an identical nonwoven fabric that does not include the small amount of the polybutylene succinate-based polyester.
- the present nonwoven fabric may exhibit an increase in tensile strength in both the machine direction and the cross direction of at least 50% in comparison to an identical nonwoven that does not include the small amount of the polybutylene succinate-based polyester.
- the increase in tensile strength allows the application of nonwoven fabrics having low basis weights, which is for instance beneficial for topsheets and backsheets. Moreover, more open bond patterns can be used without loss of mechanical performance, and improve comfort properties such as softness and drapability.
- the increase in elongation allows the use of the nonwoven fabrics in applications where elongation is important such as waist carriers, back ears and side panels. It also allows post mechanical treatments such as ring rolling, embossing and perforating.
- the at least one polybutylene succinate-based polyester is preferably present in the continuous bicomponent fibers in an amount in the range of 0.02-3.5% by weight, more preferably in the range of from 0.02-2.5% by weight, even more preferably in the range of from 0.02-2.0% by weight, and most preferably 0.02-1.5% by weight, based on the total weight of the fibers.
- the at least one polybutylene succinate-based polymer is preferably present in the sheath component in a small amount, i.e. 0.02-5% by weight, based on the total weight of the sheath component.
- the polybutylene succinate-based polyester is preferably present in the continuous bicomponent fibers in an amount in the range of 0.02-3.5% by weight, more preferably in the range of from 0.02-2.5% by weight, even more preferably in the range of from 0.02-2.0% by weight, and most preferably 0.02-1.5% by weight, based on the total weight of the sheath component.
- the at least one polybutylene succinate-based polyester to be used in accordance with the present invention may be polybutylene succinate (PBS) or a polybutylene succinate adipate (PBSA).
- PBS polybutylene succinate
- PBSA polybutylene succinate adipate
- use is made of polybutylene succinate homopolymer or polybutylene succinate copolymer.
- polybutylene succinate homopolymer Preferably, use is made of polybutylene succinate homopolymer.
- the sheath component may also comprise a mixture of different polybutylene succinates or a mixture of a polybutylene succinate and a polybutylene succinate adipate.
- the sheath component comprises only one type of polybutylene succinate-based polyester, preferably polybutylene succinate.
- Polybutylene succinate is a compostable aliphatic polyester which can be made by the polycondensation of succinic acid and 1 ,4-butanediol, whereas polybutylene succinate adipate can be made from 1,4-butanediol and a mixture of adipic acid and succinic acid.
- Polybutylene succinate polymers have for instance been described in EP 0 569 153 A2.
- the at least one polybutylene succinate-based polyester to be used in accordance with the present invention has a melt flow rate in the range of from 10-50 g/10 min. preferably in the range of from 10-40 g/10 min, more preferably in the range of from 15-35 g/10 min as determined according to ASTM D1238 (190°C, 2.16 kg).
- the at least one polybutylene succinate-based polyester to be used in accordance with the present invention suitably has a melting temperature between 80-120°C, preferably between 85-115°C.
- the at least one polybutylene succinate-based polyester has suitably a weight average molecular weight in the range of from 30,000-120,000 Dalton, preferably in the range of from 50,000-100,000 Dalton.
- the core component and/or sheath component may in addition comprises other polymers such as polyhydroxyalkanoates (PHAs), poly-3-hydroxybutyrate copolymers (P3HB), poly(3-hydroxybutyrate- co-3-hydroxyhexaoate (PHBH, poly(3-hydroxybutyrate-co- 3-hydroxyvalerate (PHBV), and the like, provided that the polymer blend in the core component has a higher crystallization grade than the polymer blend in the sheath component.
- the melt flow rate (MFR) of the first polylactic acid (PLA1) and the second polylactic acid (PLA2) to be used in the present invention is suitably less than 100 g/10 min.
- the MFR of the polylactic acid is determined using ASTM test method D1238 (210°C, 2.16 kg).
- the melt flow rate of the first and second polylactic acid is in the range of from 5- 90 g/10 min, more preferably in the range of from 10-85 g/10 min, and even more preferably in the range of from 15-45 g/ 10 min.
- the present nonwoven suitably has an area shrinkage of less than 6%, preferably less than 4, and more preferably less than 2%.
- the polymer blend composition used in the sheath component which comprises the second polylactic acid (PLA2) and the at least one polybutylene succinate-based polyester, suitably has a melt flow rate in the range of 2-100 g/10 min, preferably in the range of 4-90 g/10 min and more preferably in the range of 5-80 g/10 min, even more preferably in the range of 5-50 g/10 min, and most preferably in the range of 5-40 g/10 min, determined according to ASTM D1238 (190°C, 2.16 kg).
- the continuous bicomponent fibers to be used in accordance with the present invention suitably have a linear mass density in the range of from 1-5 dtex. In other embodiments, for instance, the continuous bicomponent fibers suitably have a dtex in the range of from 1.5-3 dtex. In further embodiments, for example, the continuous bicomponent fibers suitably have a linear mass density in the range of from 1.6-2.5 dtex.
- nonwoven fabrics in accordance with the present invention suitably exhibit tensile strengths that are 50% greater in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester.
- the present nonwoven fabric may exhibit a tensile strength that is from 50% to more than 500% greater than the tensile strength of a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the fibers.
- the nonwoven fabrics in accordance with the present invention suitably exhibit increases in machine direction (MD) tensile strengths that are from about 50 to 500% or more in comparison to a similarly prepared nonwoven fabric that does not include the polybutylene succinate-based polyester.
- MD machine direction
- the present nonwoven fabrics preferably exhibit an increase in MD tensile strength ranging from 50 to 500% or more, more preferably in the range of from 100 to 500 % or more, even more preferably from 200 to 500 % or more, and most preferably from 250 to 500% or more, in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the fibers.
- the nonwoven fabrics in accordance with the present invention suitably exhibit increases in cross direction (CD) tensile strengths that are from 50 to 800% or more in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester.
- CD cross direction
- the present nonwoven fabrics preferably exhibit an increase in CD tensile strength ranging from 50 to 800% or more, more preferably from 100 to 800% or more, even more preferably from 200 to 800% or more, and most preferably from 250 to 800% or more, in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the fibers.
- the present nonwoven fabrics in accordance with the present invention also exhibit increased toughness in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester.
- the toughness of nonwoven fabrics may be compared by examining the product resulting from the multiplication of the observed percent elongation and the observed tensile strength of the fabric.
- the product of this multiplication is referred to as the Index of Toughness, which is approximately proportional to the area under the stress strain curve.
- all tensile and elongation values are obtained according to German Method 10 DIN 53857 in which a sample having a width of 5 cm and a 100 mm gauge length at a cross-head speed of 200 mm/min were recorded at peak.
- the Index of Toughness results from the product of multiplying Tensile X % Elongation
- the Index of Toughness has units of (N/5 cm)-%. Since all mechanical properties result from testing a 5 cm wide sample, the units for Index of Toughness in this document will be simplified to N-%.
- the nonwoven fabrics in accordance with the present invention suitably exhibit an MD Index of Toughness that is in the range of from 80-2000 N-%, and in particular, in the range of from 100-1800, and more particularly, in the range of from 120-1500 N-%, and a CD Index of Toughness that is in the range of from 80-1500 N-%, and in particular, in the range of from 100-1200, and more particularly, in the range of from 120-1000 N-%.
- the nonwoven fabric in accordance with the present invention suitably exhibits an increase in MD Index of Toughness in the range from 200-5700% in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate- based polyester in the fibers.
- the present nonwoven fabric suitably exhibits an increase in CD Index of Toughness in the range from 160-3200% in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polymer in the fibers.
- the nonwoven fabrics in accordance with the present invention may exhibit an MD Relative Index of Toughness that is in the range of from 2.5-55 N-%/g/m 2 , and in particular, in the range of from 5-55 N-%/g/m 2 , and more particularly, in the range of from 10-50 N-%/g/m 2 , and a CD Relative Index of Toughness that is in the range of from 1.5-35 N-%/g/m 2 , and in particular, in the range of from 1.8-30 N-%/g/m 2 , and more particularly, in the range of from 2-30 N-%/g/m 2 .
- the presence of the at least one polybutylene succinate-based polyester helps improve bonding of the continuous bicomponent fibers to each other, which results in improvements in the mechanical properties of the nonwoven fabrics.
- the present nonwoven fabric suitably has a machine direction (MD) tensile strength at peak per gram basis weight in the range of from 0.5-2.5 (N/5 cm)/gsm.
- MD machine direction
- the present nonwoven fabric may comprise a MD tensile strength at peak per gram basis weight from 0.7-2.2 (N/5 cm)/gsm.
- the present nonwoven fabric may have a cross machine direction (CD) tensile strength at peak from 0.25-1.5 (N/5 cm)/gsm.
- the fabric may comprise a CD tensile strength at peak from 0.3- 1.1 (N/5 cm)/gsm.
- the fabric may comprise a CD tensile strength at peak from 0.5-1.9 (N/5 cm)/gsm.
- the fabric may comprise an MD elongation percentage at peak from 20-50%. In other embodiments, for example, the fabric may comprise an MD elongation percentage at peak from 25-45%. In further embodiments, for instance, the nonwoven fabric may comprise an MD elongation percentage at peak from 28- 40%.
- the fabric may comprise a CD elongation percentage at peak from 20-75%. In other embodiments, for instance, the fabric may comprise a CD elongation percentage at peak from 25-60%. In some embodiments, for example, the fabric may comprise a CD elongation percentage at peak from 30-50%.
- additional additives include thermal stabilizers, light stabilizers, slip additives, waxes, and additives to make the fabrics either hydrophilic or hydrophobic.
- the addition of filler materials can sometimes also be of advantage.
- Suitable filler materials include organic and inorganic filler materials. Suitable examples of inorganic filler materials include metals such as aluminum and stainless steel. Suitable examples of organic filler materials include sugar-based polymers.
- the continuous bicomponent fibers to be used in accordance with the present invention may in addition contain a slip agent.
- the slip agent is suitably added to the first and second component of the continuous bicomponent fibers when these are made during the manufacturing process of the fabric, e.g. in form of a masterbatch during the spinning process.
- the slip agent to be used in accordance with the present invention can be any slip agent which can suitably be used in the manufacturing of nonwoven fabrics. It can be an internal slip agent, which usually is compatible with the polymer matrix, or it can be an external slip agent that migrates to the fibers surface due to a certain incompatibility with the polymer matrix.
- the slip agent can be a hydrocarbon compound or a fatty acid derivative having one or more functional groups selected from alcohols, carboxylic acid, aryls and substituted aryls, alkoxylates, esters, amides.
- Slip agents also can be fatty acid esters of multivalent alcohols, compounds comprising unsaturated C-C bonds, oxygen, nitrogen, or a compound based on a silicone-containing compound.
- Typical examples of specifically attractive slip agents are for example, polyethylene and polypropylene waxes, primary and secondary amides such as for instance erucamide and oleamide, and stearyl derivatives.
- the slip agent is suitably present in an amount in the range of from 0.1-5 wt%, preferably in an amount of 0.5-3 wt%, based on the total weight of the core component.
- the slip agent is suitably present in an amount in the range of from 0.1-5 wt%, preferably in an amount of 0.5- 3 wt%, based on the total weight of the sheath component.
- the slip agent is suitably present in an amount in the range of from 0.1-5 wt%, preferably in an amount of 0.5-3 wt%, based on the total weight of the fibers.
- a side of the nonwoven layer is provided with a pattern of bonded areas which defines a pattern of non-bonded areas.
- the bonded areas are individualized bonded areas, meaning that the bonded areas are separately arranged, not connected to each other.
- the nonwoven layer Before or after the nonwoven layer is provided with a pattern of individualized bonded areas, the nonwoven layer may be subjected to a through-air bonding treatment.
- the side of the non-woven fabric is only provided with one type of pattern of bonded areas.
- the bonded areas are individualized bonded areas that have a circle, diamond, rectangle, square, oval, triangle, heart, moon star, rod, hexagonal, octagonal or another polygon shape.
- the bonded areas may have a circle, diamond, rectangle, square, oval, triangle, rod, heart, moon star, hexagonal, octagonal or another polygon shape.
- the pattern of individualized bonded areas may be in various shapes such as a diamond pattern, a hexagonal dot pattern, an oval-elliptic pattern, a rod-shaped pattern or any combination thereof.
- the pattern of individualized bonded areas is a continuous pattern.
- the bonded areas have a diamond, rod, oval or circular type of shape. More preferably, bonded areas have a diamond or rod type of shape. Most preferably, the bonded areas have a rod shape.
- the bonded areas suitably have a maximum width in the range of from 0.7-1.5 mm, preferably in the range of from 0.75-1.25 mm, and more preferably in the range of from 0.8- 1.2 mm.
- the bonded areas have a surface in the range of from 0.38-1.77 mm 2 , preferably in the range of from 0.44-1.22 mm 2 , and more preferably in the range of from 0.50-1.13 mm 2 .
- the individualized bonded areas are in the form of ovals may be arranged in any direction of the web.
- the bonded areas in the form of ovals are arranged in such a way that adjacent ovals which are arranged in the cross-direction form each in turn opposite angels with the machine direction of the web.
- the ovals can suitably be arranged in such a way that in the machine direction a plurality of uninterrupted regions extend continuously along the web, while in the cross direction no uninterrupted regions exist along the web.
- the width of these uninterrupted regions in the cross direction in this preferred arrangement of rods is suitably larger than 300 pm, and preferably the width is in the range of from 500-800 pm.
- At least one of the spunbond nonwoven layers comprises a side which is provided with an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction of the web.
- the present invention also relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, wherein the bonded area is more than 9% of the total surface of the side, and wherein the bonded area comprises an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction of
- the present invention relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, wherein the bonded area is more than 9% of the total surface of the side, and wherein the bonded area comprises an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction
- the present invention also relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, wherein the bonded area is more than 9% of the total surface of the side, and wherein the bonded area comprises an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction
- the rods are arranged in such a way that in the machine direction of the web no uninterrupted regions exist along the web while in the cross direction of the web the arrangement of the rods define a plurality of uninterrupted regions that extend continuously along the web.
- rod is meant to define a linear straight shape such as a straight bar or stick.
- the surface of the bonded areas in the form of rods is more than 9% of the total surface of the side.
- the bonded area in the form of rods is suitably between 10-30% of the total surface of the side. In another embodiment of the present invention, the bonded area in the form of rods is suitably between 10-20% of the total surface of the side.
- the individualized bonded areas in the form of rods each in their length direction form an angle of substantially 90° with the machine direction of the web.
- the present patterns of bonded areas in the form of rods results in a number of improved fabric properties.
- the tensile strength into the cross direction is significantly improved, as the fibers are boldly bound perpendicular to their preferred lay-down direction. It is thereby of importance that no uninterrupted regions in the preferred lay-down direction (i.e. the machine direction) exist, as this would create weak areas of unbonded fibers, resulting in a reduced tensile strength.
- the free fibers length i.e.
- the rods may have flat ends and/or bended ends.
- the bended ends have a circular shape.
- the rods have a linear shape.
- the individualized bonded areas in the form of rods have a length which is 2-10 times, preferably 2-8 times their width.
- the distance between each pair of adjacent rods is in the range of from 1.8-3.0 mm, preferably 2.2-2.6 mm in the cross direction.
- distance between each pair of adjacent rods is in the range of from 2.5-5.0 mm, preferably 3.3-4.2 mm in the machine direction.
- the distance between each pair of adjacent diamonds is in the range of from 0.15-3 mm, preferably 0.5-2.5 mm in the cross direction.
- distance between each pair of adjacent diamonds is in the range of from 0.15-3 mm, preferably 0.5-2.5 mm in the machine direction.
- the multicomponent spunbond fibers to be used in accordance with the present invention do preferably have a round fibers cross-section.
- Other suitable fibers cross-sections include for instance ribbon-shaped or trilobal-shaped cross-sections.
- the present invention also provides a process for preparing a nonwoven fabric according to the present invention, the process comprising the following steps:
- step (e) depositing the plurality of the continuous bicomponent fibers as obtained in step (d) onto a collection surface;
- step (f) bonding the plurality of continuous bicomponent fibers as obtained in step (e) to obtain the nonwoven fabric comprising a nonwoven web having a side with a surface having a bonded area which is more than 9% of the total surface of the side.
- step (e) depositing the plurality of the continuous bicomponent fibers as obtained in step (d) onto a collection surface;
- step (f) bonding the plurality of continuous bicomponent fibers as obtained in step (e) to obtain the nonwoven fabric comprising a nonwoven web having a side with a surface having a bonded area which is more than 9% of the total surface of the side.
- the present invention also provides a process for preparing a nonwoven fabric according to the present invention, the process comprising the following steps:
- step (e) depositing the plurality of the continuous bicomponent fibers as obtained in step (d) onto a collection surface;
- step (f) bonding the plurality of continuous bicomponent fibers as obtained in step (e) to obtain the nonwoven fabric comprising a nonwoven web having a side with a surface having a bonded area which is more than 9% of the total surface of the side.
- step (f) the bonding is carried out so as to obtain a nonwoven having a side with a surface with a bonded area which is between 50-100% of the total surface of the side.
- the sheath component in addition contains a small amount of at least one butylene succinate-based polyester
- the at least one polybutylene succinate-based polyester is suitably blended into the second polylactic acid (PLA2) in step (b) or step (c).
- the core component and/or the sheath component in addition contains at least one secondary alkane sulfonate
- the at least one secondary alkane sulfonate is suitably blended into the first polylactic acid (PLA1) in step (a) and/or blended into the second polylactic acid (PLA2) in step (b) or step (c).
- a fibers draw speed can suitably be applied which is greater than 2500 m/min.
- the fibers drawing can occur at a fibers draw speed from 3000-4000 m/min.
- the process may occur at a fibers draw speed from 3000-5000 m/min.
- the nonwoven web as obtained in step (e) can be bonded to form the present nonwoven fabric which bonding may comprise thermal point bonding the web with heat and pressure via a calender having a pair of cooperating rolls including a patterned roll.
- thermal point bonding the web may comprise imparting a three- dimensional geometric bonding pattern onto the present nonwoven fabric.
- the patterned roll may comprise a three-dimensional geometric bonding pattern.
- the bonded areas can suitably be individualized bonded areas that have a circle, diamond, rectangle, square, oval, triangle, heart, moon star, rod, hexagonal, octagonal or another polygon shape.
- the calender may include a release coating to minimize deposit of molten or semi molten polymer on the surface of one or more of the rolls.
- a release coating to minimize deposit of molten or semi molten polymer on the surface of one or more of the rolls.
- release coating is described in European Patent Application No. 1,432,860, which is incorporated herein in its entirety by reference.
- the present process may further comprise cutting the nonwoven fabric to form cut nonwoven fabric, exposing the cut nonwoven fabric to ions via a third ionization source, and winding the cut nonwoven fabric into rolls.
- the third ionization source may comprise an ionization bar.
- the present process may further comprise increasing humidity while forming the plurality of continuous bicomponent fibers.
- increasing humidity may comprise applying at least one of steam, fog, mist, or any combination thereof to the plurality of continuous bicomponent fibers.
- the present nonwoven fabric may be produced, for example, by a conventional spunbond process on spunbond machinery such as, for example, the Reicofil-3 line or Reicofil-4 line from Reifenhauser, as described in U.S. Pat. No. 5,814,349 to Geus et al., wherein molten fibers components are extruded into continuous bicomponent fibers which are subsequently quenched, attenuated pneumatically by a high velocity fluid, and collected in random arrangement on a collecting surface.
- the continuous fibers are collected with the aid of a vacuum source positioned below the collection surface. After filament collection, any thermal, chemical or mechanical bonding treatment may be used to form a bonded web such that a coherent web structure results.
- the collection surface may comprise conductive fibers.
- the conductive fibers may comprise monofilament wires made from polyethersulfone conditioned with polyamide (e.g., Huycon-LX 135).
- polyamide e.g., Huycon-LX 135.
- the fibers In the machine direction, the fibers comprise polyamide conditioned polyethersulfone.
- the fibers In the cross-machine direction, the fibers comprise polyamide conditioned polyethersulfone in combination with additional polyethersulfone.
- the present nonwoven fabrics may be used to prepare a variety of different structures.
- the present nonwoven fabric may be combined with one or more additional layers to prepare a composite or laminate material.
- Such composites/laminates may include a spunbond composite, a spunbond-meltblown (SM) composite, a spunbond-meltblown-spunbond (SMS) composite, or a spunbond-meltblown- meltblown-spunbond (SMMS) composite.
- composites may be prepared comprising a layer of the inventive nonwoven fabric and one or more film layers.
- the present invention further provides a nonwoven fabric comprising at least two nonwoven spunbond layers which each comprise spunbond fibers, and one or more meltblown nonwoven layers which each comprise meltblown fibers, wherein the one or more meltblown nonwoven layers are arranged between spunbond nonwoven layers, wherein the spunbond fibers of the spunbond nonwoven layers are continuous bicomponent fibers with a coresheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acids, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the
- the continuous bicomponent fibers to be used in such embodiment may be any of the continuous bicomponent fibers described previously above, including continuous bicomponent fibers in which the core component and/or sheath component include at least one secondary alkane sulfonate, and continuous bicomponent fibers in which the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.2-5% by weight, based on the total weight of the fibers.
- At least one of the meltblown layers also comprises a polylactic acid.
- the spunbond fibers and meltblown fibers are suitably joined by bonding to form a coherent web structure.
- Suitable bonding techniques include, but are not limited to, chemical bonding and thermal bonding, for example thermal calendering or air-through bonding using a hot air stream.
- Spunbond fibers are continuous bicomponent fibers that have a fibers diameter in the range of from 10-100 pm, preferably in the range of from 10-50 pm, more preferably in the range of 10-35 pm, and most preferably in the range of from 10-30 pm.
- Meltblown fibers are continuous fibers that have a fibers diameter in the range of from 0.1-10 pm, preferably in the range of from 0.5-8 pm, more preferably in the range of from 1-5 pm.
- the basis weight of the nonwoven fabric layer may range from as low as 5-150 g/m 2 .
- both the meltblown and spunbond fibers could have PLA on the surface to insure optimum bonding.
- the amount of the meltblown in the structure may range from about 5 to 30%, and in particular, from about 5 to 15% of the structure as a percentage of the structure as a whole.
- Multilayer structures in accordance with embodiments can be prepared in a variety of manners including continuous in-line processes where each layer is prepared in successive order on the same line, or depositing a meltblown layer on a previously formed spunbond layer.
- the layers of the multilayer structure can be bonded together to form a multilayer composite sheet material using thermal bonding, mechanical bonding, adhesive bonding, hydroentangling, or combinations of these.
- the layers are thermally point bonded to each other by passing the multilayer structure through a pair of calender rolls.
- the present invention also provides an article comprising the nonwoven fabric according to the present invention.
- a sustainable composite may be provided that includes at least two nonwoven fabric layers such that at least one nonwoven fabric layer comprises a layer of the present nonwoven fabric.
- the present nonwoven fabric can be used in wide variety of articles and applications.
- embodiments of the invention may be used for personal care applications, for example products for babycare (diapers, wipes), for femcare (pads, sanitary towels, tampons), for adult care (incontinence products), or for cosmetic applications (pads).
- Other possible uses include agricultural applications such as crop covers, industrial applications, for example work wear coveralls, airline pillows, automobile trunk liners, sound proofing, packaging materials, bags, pouches, and household products, for example mattress coil covers and furniture scratch pads.
- the present invention also provides to an article comprising a diaper, a sanitary pad, a container or a cover for use in respect of plants and/or agricultural applications.
- the absorbent is a diaper which comprises an absorbent core which is sandwiched between a topsheet and a backsheet
- the topsheet and the backsheet may comprise the present nonwoven fabric and/or a sustainable composite including the present nonwoven fabric layer.
- the topsheet will be positioned adjacent an outer surface of the absorbent core and is preferably joined thereto and to the backsheet by attachment means such as those well known in the art.
- the topsheet may be secured to the absorbent core by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of separate lines, spirals, or spots of adhesive.
- the present nonwoven fabrics can suitably be used in topsheets and backsheets of diapers. Moreover, in view of their high wet strength the present nonwoven fabrics can advantageously be used in wipes. In addition, the nonwoven fabrics exhibit a high elongation which allows them to be used in diaper parts such as waist carriers, back ears and side panels.
- the present invention also relates to the use of a calcium carbonate in a nonwoven fabric for reducing the area shrinkage of the nonwoven fabric, which nonwoven fabric comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount which is in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
- the core component comprises a first poly
- a nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers.
- the core component PLA1 contained 100 wt% LX530 PLA (available from Corbion), and the sheath component PLA2 contained 99.7 wt% LX530 PLA along with 0.3 wt% Sukano Antistatic Product S 546.
- Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C.
- Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam.
- Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm.
- the calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm.
- the bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
- a nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers.
- the core component PLA1 contained 100 wt% L130 PLA (available from Corbion), and the sheath component PLA2 contained 99.7 wt% LX530 PLA (Corbion) along with 0.3 wt% Sukano Antistatic Product S 546.
- Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C and the L130 had a melting point (peak temperature) in DSC of 173 °C.
- Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam.
- Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm.
- the calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm.
- the bonded pattern obtained had a bonded area of 25% and the individual areas had
- a nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers.
- the core component PLA1 contained 100 wt% LX530 PLA (available from Corbion), and the sheath component PLA2 contained 79.7 wt% LX530 PLA along with 0.3 wt% Sukano Antistatic Product S 546 and 20 wt% Omyafiber MB165-CBN (CaCO3-masterbatch available from Omya).
- Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C.
- Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam.
- Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm.
- the calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm.
- the bonded pattern obtained had a bonded area of 25% and
- a nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers.
- the core component PLA1 contained 100 wt% LX530 PLA (available from Corbion), and the sheath component PLA2 contained 76.7 wt% LX530 PLA along with 0.3 wt% Sukano Antistatic Product S 546, 3 wt% polybutylene succinate FZ78TM (available from PTT MCC BioChem) and 20 wt% Omyafiber MB165-CBN (CaCCh-masterbatch available from Omya). Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C.
- Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam.
- Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm.
- the calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm.
- the bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
- a nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers.
- the core component PLA1 contained 100 wt% L130 PLA (available from Corbion), and the sheath component PLA2 contained 89.7 wt% LX530 PLA (Corbion) along with 0.3 wt% Sukano Antistatic Product S 546 and 10 wt% Omyafiber MB165-CBN (CaCCh-masterbatch available from Omya).
- Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C and the L130 had a melting point (peak temperature) in DSC of 173 °C.
- Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam.
- Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm.
- the calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm.
- the bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
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Abstract
The present invention provides a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side. In addition, the invention further provides a process for preparing the nonwoven fabric, and an article comprising the nonwoven fabric.
Description
NONWOVEN FABRIC AND PROCESS FOR FORMING THE SAME
FIELD OF THE INVENTION
The present invention relates to a nonwoven fabric, a process for preparing the nonwoven fabric, and an article comprising the non-woven fabric.
BACKGROUND
Nonwoven fabrics are used in a variety of applications such as garments, disposable medical products, diapers, personal hygiene products, among others. New products being developed for these applications have demanding performance requirements, including comfort, conformability to the body, freedom of body movement, good softness and drape, adequate tensile strength and durability, and resistance to surface abrasion, pilling or fuzzing. Accordingly, the nonwoven fabrics which are used in these types of products must be engineered to meet these performance requirements.
Traditionally, such nonwoven fabrics are prepared from thermoplastic polymers, such as polyester, polystyrene, polyethylene, and polypropylene. These polymers are generally very stable and can remain in the environment for a long time. Recently, however, there has been a trend to develop articles and products that are considered environmentally friendly and sustainable. As part of this trend, there has been a desire to produce ecologically friendly products comprised of increased sustainable content in order to reduce the content of petroleum-based materials. Therefore, there is nowadays a need for nonwoven fabrics that are made from sustainable and degradable polymers, which polymers are preferably derivable from renewable sources.
Polylactic acid or polylactide-based polymers (PLA) provide a cost-effective path to sustainable content spunbond nonwovens that can be readily converted into consumer products. Polylactic acid (PLA) is made from vegetable renewable raw materials such as sugars from food crops such as maize, sugar beet, sugar cane and wheat or cellulose.
Polylactic acid has the advantage that it is compostable and will dissolve into carbon dioxide, biomass and water. In addition, polylactic acid is recyclable. Polylactic acid is mainly formed from the monomers lactic acid, and the cyclic di-ester, lactide. Polylactic acid is usually formed by means of ring-opening polymerization of lactide using a metal catalyst such as for instance tin octoate. Another process to form polylactic acid involves the direct condensation of lactic acid monomers.
To fully capture the cost-effective benefits of PLA-based consumer products, PLA must be convertible into nonwovens and then into the final consumer product at very high speeds with minimal waste. However, due to the propensity of static generation and accumulation on fibers with PLA polymer on the surface, it is difficult to combine the steps of spinning, web formation, and bonding at the very high speeds needed for the economically attractive production of spunbond PLA with optimum fabric properties. Moreover, when 100% PLA fibers are used, the dimensions of the manufactured nonwoven web are impacted due to the shrinking of the PLA fibers. In addition, because of the high melting temperature of PLA, high welding temperatures need to be applied when sheets of nonwoven webs made of PLA need to be welded together. These disadvantages do not allow making use of the full potential of this polymer. In addition, the electrostatic charging of 100% PLA fibers during spinning and processing also contributes to the sticking of the fibers tend to the calender roll.
To overcome these disadvantages, nonwovens have been developed with fibers having a sheath/core bicomponent structure in which the PLA is present in the core, and a synthetic polymer, such as polypropylene, is in the sheath. An example of such a nonwoven fabric is described in U.S. Pat. No. 6,506,873. The presence of such a synthetic polymer in the sheath provides the necessary properties for commercial production of nonwovens comprising PLA at high speeds. Although commercial production of nonwovens comprising PLA with petrochemical-based polymers in the sheath is possible, this solution does not extend far enough because the industry (and its consumers) are seeking for full sustainability, and thus preferably for nonwovens being made as much as possible of PLA.
Just substituting PLA by other biopolymers such as polybutylene succinate (PBS) is not a feasible alternative approach because they are not available in the necessary commercial amounts, which brings along high prices making the final fabrics too expensive, but also their spinning and processing properties are more than poor.
Accordingly, there still exists a need for fabrics which comprise PLA but which overcome the disadvantages when using fibers with very high PLA contents, and can be used in absorbent articles such as diapers and wipes, and containers and covers for use in plants and/or agriculture applications, and which deal with disadvantages that are associated with the above mentioned alternative approaches.
SUMMARY
Surprisingly, in accordance with the present invention it has been found that the addition of a calcium carbonate to at least the PLA-based sheath component of a continuous
bicomponent spunbond fiber reduces the shrinkage of the nonwoven webs considerably, and allows lower welding temperatures to be applied when sheets of PLA-based nonwoven webs need to be welded together.
Accordingly, the present invention relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
The present invention provides nonwoven fabrics, as well as sustainable composites including the present nonwoven fabrics, and sustainable articles including the present nonwoven fabrics. Examples of such sustainable articles include PLA-based hygiene articles such as diapers, containers and covers for use in respect of plants and/or agriculture applications, packaging materials, bags and pouches.
In accordance with the present invention the core component is suitably present in an amount in the range of from 50-90 wt% and the sheath component is suitably present in an amount of from 10-50 wt%, both based on total weight of the fibers. Preferably, the core component is present in an amount in the range of from 60-80 wt% and the sheath component is present in an amount of from 20-40 wt%, both based on total weight of the fibers. More preferably, the core component is present in an amount in the range of from 65- 75 wt% and the sheath component is present in an amount of from 25-35 wt%, both based on total weight of the fibers.
In one particular embodiment of the present invention, the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2).
Accordingly, the present invention relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid
(PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In accordance with the present invention, the first polylactic acid (PLA1) has suitably a melting temperature in the range of from 160-180 °C, and the second polylactic acid (PLA2) has suitably a melting temperature in the range of from 145-165 °C. Preferably, the first polylactic acid (PLA1) has a melting temperature in the range of from 165-180 °C, and the second polylactic acid (PLA2) has a melting temperature in the range of from 150-165 °C. More preferably, the first polylactic acid (PLA1) has a melting temperature in the range of from 168-175 °C, and the second polylactic acid (PLA2) has a melting temperature in the range of from 155-163 °C.
Suitably, the difference between the melting temperatures of the first polylactic acid (PLA1) and the second polylactic acid (PLA2) is between 0-35 °C, preferably between 5-25 °C, and more preferably between 10-15 °C.
In a preferred embodiment of the present invention, the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid.
Accordingly, the present invention also provides a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In accordance with the present invention the core component of the bicomponent fibers comprises a first polylactic acid (PLA1) which is suitably present in an amount in the range of from 70-100 wt%, preferably in an amount in the range of from 75-100 wt%, more preferably
in an amount in the range of from 80-100 wt%, and most preferably in an amount in the range of from 90-100 wt%, based on the total weight of the core component.
In accordance with the present invention the sheath component of the bicomponent fibers comprises a second polylactic acid (PLA2) which is suitably present in an amount in the range of from 70-99.5 wt%, preferably in an amount in the range of from 75-90 wt%, more preferably in an amount in the range of from 80-95 wt%, and most preferably in an amount in the range of from 80-92.5 wt%, based on the total weight of the sheath component.
In accordance with the present invention at least the sheath component comprises a calcium carbonate, whereby the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, preferably 5-25 wt%, more preferably 5-20 wt%, and most preferably up to 20 wt%, and most preferably 7.5-20 wt%, based on the total weight of the sheath component.
In an embodiment of the present invention, the calcium carbonate is present in both the core component and the sheath component. In that case, the calcium carbonate is suitably present in the core component in an amount in the range of from 0.5-30 wt%, based on the total weight of the core component, and the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component. If the calcium carbonate is present in both the core and sheath components, the total amount of the calcium carbonate present in the fibers is in the range of from 0.5-30 wt%, based on the total weight of the fibers.
Accordingly, the present invention also provides a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein both the core and sheath components comprise a calcium carbonate, wherein the calcium carbonate is present in the core and sheath components in an amount in the range of from 0.5-30 wt%, based on the total weight of the bicomponent fibers, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
The calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, preferably 5-20 wt%, and more preferably between 7.5-20 wt%, based on the
total weight of the sheath component.
The calcium carbonate is present in the core component in an amount in the range of from 0.5-30 wt%, preferably 5-20 wt%, and more preferably between 7.5-20 wt%, based on the total weight of the core component.
In case the calcium carbonate is present in each of the core component and the sheath component, the amount of calcium carbonate is suitably the same in both the core component and the sheath component. In one embodiment of the present invention the calcium carbonate is present in the sheath component in a higher amount than in the core component. In that case the amount of the calcium carbonate is preferably present in the sheath component in an amount in the range of 5-25 wt%, based on the total weight of the sheath component, and the calcium carbonate is preferably present in the core component, in an amount in the range of 5-20 wt%, based on the total weight of the core component.
In another embodiment of the present invention, the calcium carbonate is only present in the sheath component of the bicomponent fibers. In that case the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, preferably in an amount in the range of from 5-25 wt%, more preferably in an amount in the range of from 5- 20 wt%, and most preferably in an amount in the range of 7.5-20 wt%, based on the total weight of the sheath component.
In the present invention use is made of a calcium carbonate. The calcium carbonate may contain minor amounts of one or more other components. Such components can for instance be agents to treat the surface of the calcium carbonate or other filler components. The calcium carbonate contains suitably one or more other components in an amount of less than 5 wt%. Preferably, the calcium carbonate contains one or more other components in an amount contains less than 3 wt%, more preferably less than 1 wt%. Most preferably, the calcium carbonate is a pure (100%) calcium carbonate. The average particle size of the calcium carbonate is suitably smaller than the diameter of the bicomponent fibers. Suitably, the average particle size of the calcium carbonate is smaller than 6 pm, preferably smaller than 5 pm, more preferably smaller than 3 pm, and typically between 1.2-1.8 pm.
In accordance with the present invention the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side. The bonded area is suitably between 10-50% of the total surface of the side of the nonwoven web, and preferably between 10-20% of the total surface of the side of the
nonwoven web. In another embodiment of the present invention, the bonded area is suitably between 50-100% of the total surface of the side of the nonwoven web. In the latter embodiment the bonded area is preferably between 70-100%, more preferably between 80- 100%, even more preferably between 90-100% of the total surface of the side of the nonwoven web. In a particular embodiment of the present invention the bonded area equals 100% of the total surface of the side of the nonwoven web, which means that the surface of the side is completely bonded and thus completely flat. The embodiments of the present invention in which the bonded area is preferably between 70-100%, and more preferably 100% of the total surface of the side of the nonwoven web are particularly useful for use in containers and covers for use in respect of plants and/or agriculture applications, packaging materials, bags and pouches.
The spunbond bicomponent fibers to be used in accordance with the present invention have a core-sheath configuration. The spunbond bicomponent fibers may have a symmetric coresheath configuration or eccentric core-sheath configuration. The spunbond bicomponent fibers preferably have a symmetric core-sheath configuration.
The fibers used in accordance with the present invention are continuous bicomponent fibers. Continuous fibers have infinite length and differ essentially from staple fibers which have a limited or discreet length, generally in the range of from 2-200 mm. Synthetic staple fibers typically have limited or discreet length in the range of from 20-80 mm.
The nonwoven fabrics according to the present invention and sustainable composites including said nonwoven fabrics may be used in a wide variety of applications, including diapers, feminine care products, and incontinence products. Preferably, the present nonwoven fabrics are used in hygiene articles, more preferably in diapers. In addition, the nonwoven fabrics can be applied in the preparation of containers and covers for use in respect of plants and/or agriculture applications, packaging materials, bags and pouches.
In particularly preferred embodiment of the present invention, the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate. Suitable secondary sulfonates to be used in accordance with the present invention include those described in EP 3 500 700 B1. The at least one secondary alkane sulfonate is present in at least one of the core and sheath components. The at least one secondary alkane sulfonate can be present in the core component only, the sheath component only or in both the core and sheath components. Preferably, the at least one secondary alkane sulfonate is only present in the sheath component.
The addition of the secondary alkane sulfonate to the first polylactic acid (PLA1) and/or the second polylactic acid (PLA2) improves the mechanical properties of the nonwoven fabric. In particular, the nonwoven fabric may exhibit an increase in tensile strength, elongation, and toughness in at least one of the machine direction or cross direction in comparison to an identical fabric that does not include the at least one secondary alkane sulfonate. For example, the nonwoven fabric may exhibit an increase in tensile strength in at least one of the machine direction or cross direction of at least 50% in comparison to an identical fabric that does not include the at least one secondary alkane sulfonate in the fibers.
Accordingly, the present invention relates also to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In one particular embodiment, the present invention relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In another particular embodiment, the present invention provides a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component
comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
Preferably, the secondary alkane sulfonate is present in at least the sheath component of the bicomponent fibers. More preferably, the second alkane sulfonate is only present in the sheath component of the bicomponent fibers.
The at least one secondary alkane sulfonate is suitably present in an amount ranging from about 0.01 to 2.5 wt%, based on the total weight of the fibers. For example, the sheath component comprises a blend of the second polylactic acid (PLA2) and the at least one secondary alkane sulfonate, and wherein the at least one secondary alkane sulfonate is present in the sheath component in an amount ranging from about 0.1 to 0.75 wt%, preferably in the range of from 0.2-0.6 wt%, more preferably in the range of from 0.3-0.4 wt%, based on the total weight of the sheath component.
In some embodiments, the core component which comprises the first polylactic acid (PLA1) does not include the at least one secondary alkane sulfonate.
The core and sheath components are extruded from separate extruders, and the two fibers components are preferably arranged in substantially constantly positioned distinct zones across the cross-section of the fibers.
As used herein, the terms “nonwoven,” “nonwoven web” and “nonwoven fabric” refer to a structure or a web of material which has been formed without use of weaving or knitting processes to produce a structure of individual fibers or threads which are intermeshed, but not in an identifiable, repeating manner. Nonwoven webs have been, in the past, formed by a variety of conventional processes such as, for example, meltblown processes, spunbond processes, and staple fibers carding processes.
As used herein, the term “meltblown” refers to a process in which fibers are formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die
capillaries into a high velocity gas (e.g. air) stream which attenuates the molten thermoplastic material and forms fibers, which can be to microfibers diameter. Thereafter, the meltblown fibers are carried by the gas stream and are deposited on a collecting surface to form a web of random meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Buntin et al..
As used herein, the term “machine direction” or “MD” refers to the direction of travel of the nonwoven web during manufacturing.
As used herein, the term “cross direction” or “CD” refers to a direction that is perpendicular to the machine direction and extends laterally across the width of the nonwoven web.
As used herein, the term “spunbond” refers to a process involving extruding a molten thermoplastic material as fibers from a plurality of fine, usually circular, capillaries of a spinneret, with the fibers then being attenuated and drawn mechanically or pneumatically. In contrast with staple fibers which are short, the spunbond bicomponent fibers to be used in accordance with the present invention are continuous fibers. Hence, spunbond continuous bicomponent fibers are much longer than staple fibers. The spunbond continuous bicomponent fibers are deposited on a collecting surface to form a web of randomly arranged continuous fibers which can thereafter be bonded together to form a coherent nonwoven fabric. The production of spunbond non-woven webs is illustrated in patents such as, for example, U.S. Pat. Nos. 3,338,992; 3,692,613, 3,802,817; 4,405,297 and 5,665,300.
In general, these spunbond processes include extruding the fibers from a spinneret, quenching the continuous fibers with a flow of air to hasten the solidification of the molten fibers, attenuating the fibers by applying a draw tension, either by pneumatically entraining the fibers in an air stream or mechanically by wrapping them around mechanical draw rolls, depositing the drawn fibers onto a collection surface to form a web, and bonding the web of loose fibers into a nonwoven fabric. The bonding can be any thermal or chemical bonding treatment, such a through-air bonding or thermal point bonding.
As used herein, the term “thermal point bonding” involves passing a material such as one or more webs of fibers to be bonded between a heated calender roll and an anvil roll. The calender roll is typically patterned so that the fabric is bonded in discrete point bond sites rather than being bonded across its entire surface.
As used herein, the term “through-air bonding” involves a process in which hot air is used to
fuse the fibers at the surface of a nonwoven web and optionally internally within the nonwoven web. The hot air can either be blown through the web in an oven or sucked through the web as it passes over a porous drum as a vacuum is developed. The temperature of the hot air may be high enough to melt and/or fuse the sheath component of the continuous bicomponent fibers while not melting the core component of the continuous bicomponent fibers. The hot air may also initiate crimping of continuous bicomponent fibers.
A wide variety of different PLAs can be used in accordance with the present invention. The PLA should have proper molecular properties to be spun in spunbond processes. Examples of suitable PLA resins to be used are supplied from NatureWorks LLC, of Minnetonka, Minn. 55345 such as, grade 6752D, 6100D, and 6202D, which are believed to be produced as generally following the teaching of U.S. Pat. Nos. 5,525,706 and 6,807,973 both to Gruber et al. Other examples of suitable PLA resins may include L130, L175, LX530, and LX175, all from Corbion of Arkelsedijk 46, 4206 AC Gorinchem, the Netherlands.
Preferably, the nonwoven fabrics in accordance with the present invention are substantially free of synthetic polymer components, such as petroleum-based materials and polymers.
Both the core and sheath components of the continuous bicomponent fibers according to the present invention may comprise one or more additional additives. In such embodiments, for instance, the additive may comprise at least a colorant, a softening agent, a slip agent, an antistatic agent, a lubricant, a hydrophilic agent, a liquid repellent, an antioxidant, and the like, or any combination thereof.
The core component and/or sheath component may contain another PLA polymer. In that case, the PLA1 or blend of PLA1 with the another PLA in the core component has preferably a higher melting temperature than the PLA2 or blend of PLA2 with the another PLA in the sheath component.
Preferably, the core component of the continuous bicomponent fibers comprises only one type of PLA, viz. the first polylactic acid (PLA1). Preferably, the sheath component of the spunbond fibers comprises only one type of PLA, viz. the second polylactic acid (PLA2), which may be the same polylactic acid as the first polylactic acid (PLA1) or may be a different polylactic acid.
The first polylactic acid (PLA1) and the second polylactic acid (PLA2) to be used to be used in accordance with the present invention have suitably a weight average molecular weight in the range of from 100,000-300,000 Dalton, preferably in the range of from 150,000-250,000 Dalton.
Further, the first polylactic acid (PLA1) and the second polylactic acid (PLA2) to be used in accordance with the present invention may have different weight percentages of D isomer. For instance, the second polylactic acid (PLA2) in the sheath component may have a weight percent of D isomer up to and including 10 % by weight, and the first polylactic acid (PLA1) in the core component may have a weight percent of D isomer in the range of from 0.2-2 % by weight.
For example, the core component may comprise a first polylactic acid (PLA1) having a lower % D isomer of polylactic acid than that of the % D isomer in the second polylactic acid (PLA2) polymer used in the sheath component. The first polylactic acid (PLA1) polymer with lower % D isomer will show higher degree of stress induced crystallization during spinning while the second polylactic acid (PLA2) polymer with higher D % isomer will retain a more amorphous state during spinning. The more amorphous sheath component will promote bonding while the core showing a higher degree of crystallization will provide strength to the fibers and thus to the final bonded web. In one particular embodiment, the Nature Works PLA Grade PLA 6752 with 4% D Isomer can be used as the sheath while NatureWorks Grade 6202 with 2% D Isomer can be used as the core component.
In a preferred embodiment of the present invention, the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers.
Accordingly, the present invention relates also to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the sheath component comprises in addition at least one polybutylene succinate- based polyester which is present in an amount in the range of from 0.02-5% by weight,
based on the total weight of the fibers, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In one particular embodiment, the present invention provides a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein at least the sheath component comprises in addition at least one polybutylene succinate- based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In another particular embodiment, the present invention provides to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the sheath component comprises in addition at least one polybutylene succinate- based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In a particularly preferred embodiment, the present invention provides a nonwoven fabric which comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second
polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein at least the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In one particularly preferred embodiment, the present invention provides a nonwoven fabric which comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein at least the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In another particularly preferred embodiment, the present invention provides a nonwoven fabric which comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the continuous bicomponent fibers comprise in addition at least one secondary alkane sulfonate, wherein at least the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers, wherein the
nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
In this particularly preferred embodiment, the at least one secondary alkane sulfonate is suitably present in an amount ranging from about 0.01 to 2.5 wt%, based on the total weight of the fibers.
Preferably, the at least one secondary alkane sulfonate is preferably present in at least the sheath component of the continuous bicomponent fibers.
The additional use in the sheath component of a polybutylene succinate-based polyester has the advantage that the nonwoven fabric exhibits a considerable increase in tensile strength and elongation in both the machine direction and the cross direction in comparison to an identical nonwoven fabric that does not include the small amount of the polybutylene succinate-based polyester. For example, the present nonwoven fabric may exhibit an increase in tensile strength in both the machine direction and the cross direction of at least 50% in comparison to an identical nonwoven that does not include the small amount of the polybutylene succinate-based polyester.
The increase in tensile strength allows the application of nonwoven fabrics having low basis weights, which is for instance beneficial for topsheets and backsheets. Moreover, more open bond patterns can be used without loss of mechanical performance, and improve comfort properties such as softness and drapability.
In addition, the increase in elongation allows the use of the nonwoven fabrics in applications where elongation is important such as waist carriers, back ears and side panels. It also allows post mechanical treatments such as ring rolling, embossing and perforating.
The at least one polybutylene succinate-based polyester is preferably present in the continuous bicomponent fibers in an amount in the range of 0.02-3.5% by weight, more preferably in the range of from 0.02-2.5% by weight, even more preferably in the range of from 0.02-2.0% by weight, and most preferably 0.02-1.5% by weight, based on the total weight of the fibers.
The at least one polybutylene succinate-based polymer is preferably present in the sheath component in a small amount, i.e. 0.02-5% by weight, based on the total weight of the sheath component. The polybutylene succinate-based polyester is preferably present in the
continuous bicomponent fibers in an amount in the range of 0.02-3.5% by weight, more preferably in the range of from 0.02-2.5% by weight, even more preferably in the range of from 0.02-2.0% by weight, and most preferably 0.02-1.5% by weight, based on the total weight of the sheath component.
The at least one polybutylene succinate-based polyester to be used in accordance with the present invention may be polybutylene succinate (PBS) or a polybutylene succinate adipate (PBSA). Suitably, use is made of polybutylene succinate homopolymer or polybutylene succinate copolymer. Preferably, use is made of polybutylene succinate homopolymer. In accordance with the present invention, the sheath component may also comprise a mixture of different polybutylene succinates or a mixture of a polybutylene succinate and a polybutylene succinate adipate. Preferably, the sheath component comprises only one type of polybutylene succinate-based polyester, preferably polybutylene succinate. Polybutylene succinate is a compostable aliphatic polyester which can be made by the polycondensation of succinic acid and 1 ,4-butanediol, whereas polybutylene succinate adipate can be made from 1,4-butanediol and a mixture of adipic acid and succinic acid. Polybutylene succinate polymers have for instance been described in EP 0 569 153 A2.
Suitably, the at least one polybutylene succinate-based polyester to be used in accordance with the present invention has a melt flow rate in the range of from 10-50 g/10 min. preferably in the range of from 10-40 g/10 min, more preferably in the range of from 15-35 g/10 min as determined according to ASTM D1238 (190°C, 2.16 kg).
The at least one polybutylene succinate-based polyester to be used in accordance with the present invention suitably has a melting temperature between 80-120°C, preferably between 85-115°C.
The at least one polybutylene succinate-based polyester has suitably a weight average molecular weight in the range of from 30,000-120,000 Dalton, preferably in the range of from 50,000-100,000 Dalton.
Further, the core component and/or sheath component may in addition comprises other polymers such as polyhydroxyalkanoates (PHAs), poly-3-hydroxybutyrate copolymers (P3HB), poly(3-hydroxybutyrate- co-3-hydroxyhexaoate (PHBH, poly(3-hydroxybutyrate-co- 3-hydroxyvalerate (PHBV), and the like, provided that the polymer blend in the core component has a higher crystallization grade than the polymer blend in the sheath component.
The melt flow rate (MFR) of the first polylactic acid (PLA1) and the second polylactic acid (PLA2) to be used in the present invention is suitably less than 100 g/10 min. The MFR of the polylactic acid is determined using ASTM test method D1238 (210°C, 2.16 kg). Preferably, the melt flow rate of the first and second polylactic acid is in the range of from 5- 90 g/10 min, more preferably in the range of from 10-85 g/10 min, and even more preferably in the range of from 15-45 g/ 10 min.
The present nonwoven fabric may suitably have a basis weight in the range of from 5-150 grams per square meter (gsm). In some embodiments, the present nonwoven fabric may have a basis weight in the range of 8-100 gsm. Preferably, the present nonwoven fabric has a basis weight of less than 50 gsm. Preferably, the nonwoven fabric has a basis weight in the range of from 10-50 gsm, more preferably in the range of 10-30 gsm, and most preferably in the range of from 10-25 gsm.
The present nonwoven suitably has an area shrinkage of less than 6%, preferably less than 4, and more preferably less than 2%.
The polymer blend composition used in the sheath component, which comprises the second polylactic acid (PLA2) and the at least one polybutylene succinate-based polyester, suitably has a melt flow rate in the range of 2-100 g/10 min, preferably in the range of 4-90 g/10 min and more preferably in the range of 5-80 g/10 min, even more preferably in the range of 5-50 g/10 min, and most preferably in the range of 5-40 g/10 min, determined according to ASTM D1238 (190°C, 2.16 kg).
The continuous bicomponent fibers to be used in accordance with the present invention suitably have a linear mass density in the range of from 1-5 dtex. In other embodiments, for instance, the continuous bicomponent fibers suitably have a dtex in the range of from 1.5-3 dtex. In further embodiments, for example, the continuous bicomponent fibers suitably have a linear mass density in the range of from 1.6-2.5 dtex.
Advantageously, in accordance with the present invention it has been found that the addition of a small amount of the at least one polybutylene succinate-based polyester to the continuous bicomponent fibers provides significant increases in mechanical properties in comparison to an identical or similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the continuous bicomponent fibers. In this regard, nonwoven fabrics in accordance with the present invention suitably exhibit
tensile strengths that are 50% greater in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester. The present nonwoven fabric may exhibit a tensile strength that is from 50% to more than 500% greater than the tensile strength of a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the fibers.
The nonwoven fabrics in accordance with the present invention suitably exhibit increases in machine direction (MD) tensile strengths that are from about 50 to 500% or more in comparison to a similarly prepared nonwoven fabric that does not include the polybutylene succinate-based polyester. The present nonwoven fabrics preferably exhibit an increase in MD tensile strength ranging from 50 to 500% or more, more preferably in the range of from 100 to 500 % or more, even more preferably from 200 to 500 % or more, and most preferably from 250 to 500% or more, in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the fibers.
The nonwoven fabrics in accordance with the present invention suitably exhibit increases in cross direction (CD) tensile strengths that are from 50 to 800% or more in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester. In some embodiments, the present nonwoven fabrics preferably exhibit an increase in CD tensile strength ranging from 50 to 800% or more, more preferably from 100 to 800% or more, even more preferably from 200 to 800% or more, and most preferably from 250 to 800% or more, in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the fibers.
The present nonwoven fabrics in accordance with the present invention also exhibit increased toughness in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester. The toughness of nonwoven fabrics may be compared by examining the product resulting from the multiplication of the observed percent elongation and the observed tensile strength of the fabric. The product of this multiplication is referred to as the Index of Toughness, which is approximately proportional to the area under the stress strain curve. As discussed below in the Test Methods section, all tensile and elongation values are obtained according to German Method 10 DIN 53857 in which a sample having a width of 5 cm and a 100 mm gauge length at a cross-head speed of 200 mm/min were recorded at peak. Since Index of Toughness results from the product of multiplying Tensile X % Elongation, the Index of Toughness has units of (N/5 cm)-%. Since all mechanical properties result from testing a 5 cm wide sample, the units for Index of Toughness in this document will be simplified to N-%.
The nonwoven fabrics in accordance with the present invention suitably exhibit an MD Index of Toughness that is in the range of from 80-2000 N-%, and in particular, in the range of from 100-1800, and more particularly, in the range of from 120-1500 N-%, and a CD Index of Toughness that is in the range of from 80-1500 N-%, and in particular, in the range of from 100-1200, and more particularly, in the range of from 120-1000 N-%.
The nonwoven fabric in accordance with the present invention suitably exhibits an increase in MD Index of Toughness in the range from 200-5700% in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate- based polyester in the fibers.
In some embodiments, the present nonwoven fabric suitably exhibits an increase in CD Index of Toughness in the range from 160-3200% in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polymer in the fibers.
To account for variations in basis weights, it may also be useful to consider Relative Index of Toughness for the inventive nonwoven fabrics in comparison to similarly prepared nonwoven fabrics that do not include the at least one polybutylene succinate-based polymer in the fibers. The present nonwoven fabrics also exhibited significant increases in toughness in comparison to in comparison to similarly prepared nonwoven fabrics that do not include the at least one polybutylene succinate-based polymer in the fibers. The Relative Index of Toughness is calculated from the Index of Toughness, which is then normalized for basis weight. The Toughness Index can be divided by basis weight to provide a normalized Index of Toughness with units of N-%/g/m2.
The nonwoven fabrics in accordance with the present invention may exhibit an MD Relative Index of Toughness that is in the range of from 2.5-55 N-%/g/m2, and in particular, in the range of from 5-55 N-%/g/m2, and more particularly, in the range of from 10-50 N-%/g/m2, and a CD Relative Index of Toughness that is in the range of from 1.5-35 N-%/g/m2, and in particular, in the range of from 1.8-30 N-%/g/m2, and more particularly, in the range of from 2-30 N-%/g/m2.
In some embodiments, the inventive nonwoven fabric may exhibit an increase in MD Relative Index of Toughness in the range from 100-3500% in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate- based polyester in the fibers.
The present nonwoven fabric may exhibit an increase in CD Relative Index of Toughness in the range from 100-2000% in comparison to a similarly prepared nonwoven fabric that does not include the at least one polybutylene succinate-based polyester in the fibers.
By “similarly prepared nonwoven fabric” it should be understood the comparison nonwoven fabric has the identical polymer composition with the exception of the polybutylene succinate-based polyester, and that slight variations in processing conditions, such as temperature (e.g., extruder, calendaring, and die temperatures), draw speeds, and pressures may exist.
The presence of the at least one polybutylene succinate-based polyester helps improve bonding of the continuous bicomponent fibers to each other, which results in improvements in the mechanical properties of the nonwoven fabrics.
The present nonwoven fabric suitably has a machine direction (MD) tensile strength at peak per gram basis weight in the range of from 0.5-2.5 (N/5 cm)/gsm. For instance, the present nonwoven fabric may comprise a MD tensile strength at peak per gram basis weight from 0.7-2.2 (N/5 cm)/gsm.
In certain embodiments, for example, the present nonwoven fabric may have a cross machine direction (CD) tensile strength at peak from 0.25-1.5 (N/5 cm)/gsm. In other embodiments, for instance, the fabric may comprise a CD tensile strength at peak from 0.3- 1.1 (N/5 cm)/gsm. In some embodiments, for example, the fabric may comprise a CD tensile strength at peak from 0.5-1.9 (N/5 cm)/gsm.
According to certain embodiments, for instance, the fabric may comprise an MD elongation percentage at peak from 20-50%. In other embodiments, for example, the fabric may comprise an MD elongation percentage at peak from 25-45%. In further embodiments, for instance, the nonwoven fabric may comprise an MD elongation percentage at peak from 28- 40%.
In certain embodiments, for example, the fabric may comprise a CD elongation percentage at peak from 20-75%. In other embodiments, for instance, the fabric may comprise a CD elongation percentage at peak from 25-60%. In some embodiments, for example, the fabric may comprise a CD elongation percentage at peak from 30-50%.
Besides additives that already be present in the first polylactic acid (PLA1) and the second polylactic acid (PLA2), addition of further additives is possible to provide additional properties to the fibers. Suitable further additives include thermal stabilizers, light stabilizers, slip additives, waxes, and additives to make the fabrics either hydrophilic or hydrophobic. The addition of filler materials can sometimes also be of advantage. Suitable filler materials include organic and inorganic filler materials. Suitable examples of inorganic filler materials include metals such as aluminum and stainless steel. Suitable examples of organic filler materials include sugar-based polymers.
The continuous bicomponent fibers to be used in accordance with the present invention may in addition contain a slip agent. The slip agent is suitably added to the first and second component of the continuous bicomponent fibers when these are made during the manufacturing process of the fabric, e.g. in form of a masterbatch during the spinning process.
The slip agent to be used in accordance with the present invention can be any slip agent which can suitably be used in the manufacturing of nonwoven fabrics. It can be an internal slip agent, which usually is compatible with the polymer matrix, or it can be an external slip agent that migrates to the fibers surface due to a certain incompatibility with the polymer matrix. Suitably, the slip agent can be a hydrocarbon compound or a fatty acid derivative having one or more functional groups selected from alcohols, carboxylic acid, aryls and substituted aryls, alkoxylates, esters, amides. Slip agents also can be fatty acid esters of multivalent alcohols, compounds comprising unsaturated C-C bonds, oxygen, nitrogen, or a compound based on a silicone-containing compound.
Typical examples of specifically attractive slip agents are for example, polyethylene and polypropylene waxes, primary and secondary amides such as for instance erucamide and oleamide, and stearyl derivatives.
The slip agent is suitably present in an amount in the range of from 0.1-5 wt%, preferably in an amount of 0.5-3 wt%, based on the total weight of the core component. The slip agent is suitably present in an amount in the range of from 0.1-5 wt%, preferably in an amount of 0.5- 3 wt%, based on the total weight of the sheath component.
The slip agent is suitably present in an amount in the range of from 0.1-5 wt%, preferably in an amount of 0.5-3 wt%, based on the total weight of the fibers.
Suitably, a side of the nonwoven layer is provided with a pattern of bonded areas which defines a pattern of non-bonded areas. Preferably, the bonded areas are individualized bonded areas, meaning that the bonded areas are separately arranged, not connected to each other. Before or after the nonwoven layer is provided with a pattern of individualized bonded areas, the nonwoven layer may be subjected to a through-air bonding treatment.
Preferably, the side of the non-woven fabric is only provided with one type of pattern of bonded areas.
Preferably, the bonded areas are individualized bonded areas that have a circle, diamond, rectangle, square, oval, triangle, heart, moon star, rod, hexagonal, octagonal or another polygon shape.
The bonded areas may have a circle, diamond, rectangle, square, oval, triangle, rod, heart, moon star, hexagonal, octagonal or another polygon shape. For instance, the pattern of individualized bonded areas may be in various shapes such as a diamond pattern, a hexagonal dot pattern, an oval-elliptic pattern, a rod-shaped pattern or any combination thereof. Suitably, the pattern of individualized bonded areas is a continuous pattern.
In a preferred embodiment of the present invention the bonded areas have a diamond, rod, oval or circular type of shape. More preferably, bonded areas have a diamond or rod type of shape. Most preferably, the bonded areas have a rod shape.
Suitably, the bonded areas suitably have a maximum width in the range of from 0.7-1.5 mm, preferably in the range of from 0.75-1.25 mm, and more preferably in the range of from 0.8- 1.2 mm.
Suitably, the bonded areas have a surface in the range of from 0.38-1.77 mm2, preferably in the range of from 0.44-1.22 mm2, and more preferably in the range of from 0.50-1.13 mm2.
In case the individualized bonded areas are in the form of ovals may be arranged in any direction of the web. Preferably, the bonded areas in the form of ovals are arranged in such a way that adjacent ovals which are arranged in the cross-direction form each in turn opposite angels with the machine direction of the web. The ovals can suitably be arranged in such a way that in the machine direction a plurality of uninterrupted regions extend continuously along the web, while in the cross direction no uninterrupted regions exist along the web. The width of these uninterrupted regions in the cross direction in this preferred
arrangement of rods is suitably larger than 300 pm, and preferably the width is in the range of from 500-800 pm.
In another preferred embodiment accordance with the present invention at least one of the spunbond nonwoven layers comprises a side which is provided with an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction of the web.
Therefore, the present invention also relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, wherein the bonded area is more than 9% of the total surface of the side, and wherein the bonded area comprises an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction of the web.
In a particular embodiment, the present invention relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, wherein the bonded area is more than 9% of the total surface of the side, and wherein the bonded area comprises an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction of the web.
In another particular embodiment, the present invention also relates to a nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers fibers with a core-sheath configuration in which the core
component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, wherein the bonded area is more than 9% of the total surface of the side, and wherein the bonded area comprises an alternating pattern of individualized bonded areas which are in the form of rods which are arranged in the cross direction of the web.
Preferably, the rods are arranged in such a way that in the machine direction of the web no uninterrupted regions exist along the web while in the cross direction of the web the arrangement of the rods define a plurality of uninterrupted regions that extend continuously along the web.
In the context of the present invention the term “rod” is meant to define a linear straight shape such as a straight bar or stick.
The surface of the bonded areas in the form of rods is more than 9% of the total surface of the side. The bonded area in the form of rods is suitably between 10-30% of the total surface of the side. In another embodiment of the present invention, the bonded area in the form of rods is suitably between 10-20% of the total surface of the side.
Preferably, the individualized bonded areas in the form of rods each in their length direction form an angle of substantially 90° with the machine direction of the web. The present patterns of bonded areas in the form of rods results in a number of improved fabric properties. The tensile strength into the cross direction is significantly improved, as the fibers are boldly bound perpendicular to their preferred lay-down direction. It is thereby of importance that no uninterrupted regions in the preferred lay-down direction (i.e. the machine direction) exist, as this would create weak areas of unbonded fibers, resulting in a reduced tensile strength. Moreover, since there are no uninterrupted regions in the machine direction along the web, the free fibers length (i.e. average length of a single fibers between its first and second bond) is comparatively short, resulting in an improved abrasion resistance. Further, this particular arrangement of rods provides uninterrupted non-bonded areas in the cross direction, significantly reducing the bending forces of the fabric and translating into an excellent drapability without sacrificing mechanical strength. This finding is surprising because these two properties usually exclude each other.
The rods may have flat ends and/or bended ends. Preferably, the bended ends have a circular shape. Preferably, the rods have a linear shape. Suitably, the individualized bonded areas in the form of rods have a length which is 2-10 times, preferably 2-8 times their width.
The discrete non-bonded areas between the rods suitably have a depth in the range of from 0.1 -0.8 mm, preferably in the range of from 0.1 -0.6 mm, more preferably in the range of from 0.15-0.5 mm, and most preferably in the range of from 0.15-0.4 mm.
Suitably, the distance between each pair of adjacent rods is in the range of from 1.8-3.0 mm, preferably 2.2-2.6 mm in the cross direction. Suitably, distance between each pair of adjacent rods is in the range of from 2.5-5.0 mm, preferably 3.3-4.2 mm in the machine direction.
When the individualized bonded areas have a diamond shape, the distance between each pair of adjacent diamonds is in the range of from 0.15-3 mm, preferably 0.5-2.5 mm in the cross direction. Suitably, distance between each pair of adjacent diamonds is in the range of from 0.15-3 mm, preferably 0.5-2.5 mm in the machine direction.
The multicomponent spunbond fibers to be used in accordance with the present invention do preferably have a round fibers cross-section. Other suitable fibers cross-sections include for instance ribbon-shaped or trilobal-shaped cross-sections.
The present invention also provides a process for preparing a nonwoven fabric according to the present invention, the process comprising the following steps:
(a) providing a stream of a molten or semi-molten first polylactic acid (PLA1);
(b) providing a stream of a molten or semi-molten second polylactic acid (PLA2);
(c) blending a calcium carbonate with at least the second polylactic acid (PLA2);
(d) forming from the streams of the first polylactic acid (PLA1) and the second polylactic acid (PLA2) continuous spunbond bicomponent fibers having a core-sheath configuration in which the core component comprises the first polylactic acid (PLA1) and the sheath component comprises the second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acids, wherein at least the sheath component comprises a calcium carbonate, and wherein the calcium carbonate is present in the sheath component in an amount which is in the range of from 0.5-30 wt%, based on the total weight of the sheath component; and
(e) depositing the plurality of the continuous bicomponent fibers as obtained in step (d)
onto a collection surface; and
(f) bonding the plurality of continuous bicomponent fibers as obtained in step (e) to obtain the nonwoven fabric comprising a nonwoven web having a side with a surface having a bonded area which is more than 9% of the total surface of the side.
In a particular embodiment, the present invention also provides a process for preparing a nonwoven fabric according to the present invention, the process comprising the following steps:
(a) providing a stream of a molten or semi-molten first polylactic acid (PLA1);
(b) providing a stream of a molten or semi-molten second polylactic acid (PLA2);
(c) blending a calcium carbonate with at least the second polylactic acid (PLA2);
(d) forming from the streams of the first polylactic acid (PLA1) and the second polylactic acid (PLA2) continuous spunbond bicomponent fibers having a core-sheath configuration in which the core component comprises the first polylactic acid (PLA1) and the sheath component comprises the second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2), wherein at least the sheath component comprises a calcium carbonate, and wherein the calcium carbonate is present in the sheath component in an amount which is in the range of from 0.5-30 wt%, based on the total weight of the sheath component; and
(e) depositing the plurality of the continuous bicomponent fibers as obtained in step (d) onto a collection surface; and
(f) bonding the plurality of continuous bicomponent fibers as obtained in step (e) to obtain the nonwoven fabric comprising a nonwoven web having a side with a surface having a bonded area which is more than 9% of the total surface of the side.
In another particular embodiment, the present invention also provides a process for preparing a nonwoven fabric according to the present invention, the process comprising the following steps:
(a) providing a stream of a molten or semi-molten first polylactic acid (PLA1);
(b) providing a stream of a molten or semi-molten second polylactic acid (PLA2);
(c) blending a calcium carbonate with at least the second polylactic acid (PLA2);
(d) forming from the streams of the first polylactic acid PLA1 and the second polylactic acid (PLA2) continuous spunbond bicomponent fibers having a core-sheath configuration in which the core component comprises the first polylactic acid (PLA1) and the sheath component comprises the second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid, wherein at least the sheath component comprises a calcium carbonate, and wherein the calcium carbonate is
present in the sheath component in an amount which is in the range of from 0.5-30 wt%, based on the total weight of the sheath component; and
(e) depositing the plurality of the continuous bicomponent fibers as obtained in step (d) onto a collection surface; and
(f) bonding the plurality of continuous bicomponent fibers as obtained in step (e) to obtain the nonwoven fabric comprising a nonwoven web having a side with a surface having a bonded area which is more than 9% of the total surface of the side.
In step (f) the bonding is carried out so as to obtain a nonwoven having a side with a surface with a bonded area which is between 50-100% of the total surface of the side.
When the sheath component in addition contains a small amount of at least one butylene succinate-based polyester, the at least one polybutylene succinate-based polyester is suitably blended into the second polylactic acid (PLA2) in step (b) or step (c).
When the core component and/or the sheath component in addition contains at least one secondary alkane sulfonate, the at least one secondary alkane sulfonate is suitably blended into the first polylactic acid (PLA1) in step (a) and/or blended into the second polylactic acid (PLA2) in step (b) or step (c).
In step (d), a fibers draw speed can suitably be applied which is greater than 2500 m/min. In other embodiments, for example, the fibers drawing can occur at a fibers draw speed from 3000-4000 m/min. In further embodiments, for instance, the process may occur at a fibers draw speed from 3000-5000 m/min.
The nonwoven web as obtained in step (e) can be bonded to form the present nonwoven fabric which bonding may comprise thermal point bonding the web with heat and pressure via a calender having a pair of cooperating rolls including a patterned roll. In such embodiments, for example, thermal point bonding the web may comprise imparting a three- dimensional geometric bonding pattern onto the present nonwoven fabric. The patterned roll may comprise a three-dimensional geometric bonding pattern. In the bonding pattern the bonded areas can suitably be individualized bonded areas that have a circle, diamond, rectangle, square, oval, triangle, heart, moon star, rod, hexagonal, octagonal or another polygon shape.
The calender may include a release coating to minimize deposit of molten or semi molten polymer on the surface of one or more of the rolls. As an example, such release coating is
described in European Patent Application No. 1,432,860, which is incorporated herein in its entirety by reference.
The present process may further comprise cutting the nonwoven fabric to form cut nonwoven fabric, exposing the cut nonwoven fabric to ions via a third ionization source, and winding the cut nonwoven fabric into rolls. In such embodiments, for example, the third ionization source may comprise an ionization bar.
The present process may further comprise increasing humidity while forming the plurality of continuous bicomponent fibers. In such embodiments, for example, increasing humidity may comprise applying at least one of steam, fog, mist, or any combination thereof to the plurality of continuous bicomponent fibers.
The present nonwoven fabric may be produced, for example, by a conventional spunbond process on spunbond machinery such as, for example, the Reicofil-3 line or Reicofil-4 line from Reifenhauser, as described in U.S. Pat. No. 5,814,349 to Geus et al., wherein molten fibers components are extruded into continuous bicomponent fibers which are subsequently quenched, attenuated pneumatically by a high velocity fluid, and collected in random arrangement on a collecting surface. In some embodiments, the continuous fibers are collected with the aid of a vacuum source positioned below the collection surface. After filament collection, any thermal, chemical or mechanical bonding treatment may be used to form a bonded web such that a coherent web structure results. As one skilled in the art will understand, examples of thermal bonding may include thru-air bonding where hot air is forced through the web to soften the polymer on the outside of certain fibers in the web followed by at least limited compression of the web or calender bonding where the web is compressed between two rolls, at least one of which is heated, and typically one is an embossed roll.
In some embodiments of the present process, the collection surface may comprise conductive fibers. The conductive fibers may comprise monofilament wires made from polyethersulfone conditioned with polyamide (e.g., Huycon-LX 135). In the machine direction, the fibers comprise polyamide conditioned polyethersulfone. In the cross-machine direction, the fibers comprise polyamide conditioned polyethersulfone in combination with additional polyethersulfone.
The present nonwoven fabrics may be used to prepare a variety of different structures. For example, in some embodiments, the present nonwoven fabric may be combined with one or
more additional layers to prepare a composite or laminate material. Examples of such composites/laminates may include a spunbond composite, a spunbond-meltblown (SM) composite, a spunbond-meltblown-spunbond (SMS) composite, or a spunbond-meltblown- meltblown-spunbond (SMMS) composite. In some embodiments, composites may be prepared comprising a layer of the inventive nonwoven fabric and one or more film layers.
The present invention further provides a nonwoven fabric comprising at least two nonwoven spunbond layers which each comprise spunbond fibers, and one or more meltblown nonwoven layers which each comprise meltblown fibers, wherein the one or more meltblown nonwoven layers are arranged between spunbond nonwoven layers, wherein the spunbond fibers of the spunbond nonwoven layers are continuous bicomponent fibers with a coresheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acids, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
The continuous bicomponent fibers to be used in such embodiment may be any of the continuous bicomponent fibers described previously above, including continuous bicomponent fibers in which the core component and/or sheath component include at least one secondary alkane sulfonate, and continuous bicomponent fibers in which the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.2-5% by weight, based on the total weight of the fibers.
In such multilayer nonwoven fabric embodiment, at least one of the meltblown layers also comprises a polylactic acid.
The spunbond fibers and meltblown fibers are suitably joined by bonding to form a coherent web structure. Suitable bonding techniques include, but are not limited to, chemical bonding and thermal bonding, for example thermal calendering or air-through bonding using a hot air stream.
Spunbond fibers are continuous bicomponent fibers that have a fibers diameter in the range
of from 10-100 pm, preferably in the range of from 10-50 pm, more preferably in the range of 10-35 pm, and most preferably in the range of from 10-30 pm.
Meltblown fibers are continuous fibers that have a fibers diameter in the range of from 0.1-10 pm, preferably in the range of from 0.5-8 pm, more preferably in the range of from 1-5 pm.
In these multilayer structures, the basis weight of the nonwoven fabric layer may range from as low as 5-150 g/m2. In such multilayered laminates, both the meltblown and spunbond fibers could have PLA on the surface to insure optimum bonding. In some embodiments in which the spunbond layer is a part of a multilayer structure (e.g., SM, SMS, and SMMS), the amount of the meltblown in the structure may range from about 5 to 30%, and in particular, from about 5 to 15% of the structure as a percentage of the structure as a whole.
Multilayer structures in accordance with embodiments can be prepared in a variety of manners including continuous in-line processes where each layer is prepared in successive order on the same line, or depositing a meltblown layer on a previously formed spunbond layer. The layers of the multilayer structure can be bonded together to form a multilayer composite sheet material using thermal bonding, mechanical bonding, adhesive bonding, hydroentangling, or combinations of these. In certain embodiments, the layers are thermally point bonded to each other by passing the multilayer structure through a pair of calender rolls.
The present invention also provides an article comprising the nonwoven fabric according to the present invention. In one embodiment, a sustainable composite may be provided that includes at least two nonwoven fabric layers such that at least one nonwoven fabric layer comprises a layer of the present nonwoven fabric.
The present nonwoven fabric can be used in wide variety of articles and applications. For instance, embodiments of the invention may be used for personal care applications, for example products for babycare (diapers, wipes), for femcare (pads, sanitary towels, tampons), for adult care (incontinence products), or for cosmetic applications (pads). Other possible uses include agricultural applications such as crop covers, industrial applications, for example work wear coveralls, airline pillows, automobile trunk liners, sound proofing, packaging materials, bags, pouches, and household products, for example mattress coil covers and furniture scratch pads.
Accordingly, the present invention also provides to an article comprising a diaper, a sanitary pad, a container or a cover for use in respect of plants and/or agricultural applications.
When the absorbent is a diaper which comprises an absorbent core which is sandwiched between a topsheet and a backsheet, one or both of the topsheet and the backsheet may comprise the present nonwoven fabric and/or a sustainable composite including the present nonwoven fabric layer. The topsheet will be positioned adjacent an outer surface of the absorbent core and is preferably joined thereto and to the backsheet by attachment means such as those well known in the art. For example, the topsheet may be secured to the absorbent core by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of separate lines, spirals, or spots of adhesive.
Hence, the present nonwoven fabrics can suitably be used in topsheets and backsheets of diapers. Moreover, in view of their high wet strength the present nonwoven fabrics can advantageously be used in wipes. In addition, the nonwoven fabrics exhibit a high elongation which allows them to be used in diaper parts such as waist carriers, back ears and side panels.
The present invention also relates to the use of a calcium carbonate in a nonwoven fabric for reducing the area shrinkage of the nonwoven fabric, which nonwoven fabric comprises a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount which is in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
Examples
Comparative Example 1
A nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers. The core component PLA1 contained 100 wt% LX530 PLA (available from Corbion), and the sheath component PLA2 contained 99.7 wt% LX530 PLA along with 0.3 wt% Sukano Antistatic Product S 546. Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C. Spinning temperature was 230 °C at the
extruder and 235 °C at the spin beam. Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm. The calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm. The bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
Part of the nonwoven fabric so obtained was dried for 24 hours at a temperature of 55 °C. The percentage of area shrinkage as a result of this drying step is shown in Table 1.
Comparative Example 2
A nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers. The core component PLA1 contained 100 wt% L130 PLA (available from Corbion), and the sheath component PLA2 contained 99.7 wt% LX530 PLA (Corbion) along with 0.3 wt% Sukano Antistatic Product S 546. Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C and the L130 had a melting point (peak temperature) in DSC of 173 °C. Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam. Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm. The calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm. The bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
Part of the nonwoven fabric so obtained was dried for 24 hours at a temperature of 55 °C. The percentage of area shrinkage as a result of this drying step is shown in Table 2.
Inventive Example 1
A nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers. The core component PLA1 contained 100 wt% LX530 PLA (available from Corbion), and the sheath component PLA2 contained 79.7 wt% LX530 PLA along with 0.3 wt% Sukano Antistatic Product S 546 and 20 wt% Omyafiber MB165-CBN (CaCO3-masterbatch available from Omya). Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C. Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam. Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm. The calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm. The bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
Part of the nonwoven fabric so obtained was dried for 24 hours at a temperature of 55 °C. The percentage of area shrinkage as a result of this drying step is shown in Table 1.
Inventive Example 2
A nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers. The core component PLA1 contained 100 wt% LX530 PLA (available from Corbion), and the sheath component PLA2 contained 76.7 wt% LX530 PLA along with 0.3 wt% Sukano Antistatic Product S 546, 3 wt% polybutylene succinate FZ78TM (available from PTT MCC BioChem) and 20 wt% Omyafiber MB165-CBN (CaCCh-masterbatch available from Omya). Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C. Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam. Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm. The calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm. The bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
Part of the nonwoven fabric so obtained was dried for 24 hours at a temperature of 55 °C. The percentage of area shrinkage as a result of this drying step is shown in Table 1.
Inventive Example 3
A nonwoven fabric was made of bicomponent 30/70 PLA2/PLA1 sheath/core fibers. The core component PLA1 contained 100 wt% L130 PLA (available from Corbion), and the sheath component PLA2 contained 89.7 wt% LX530 PLA (Corbion) along with 0.3 wt% Sukano Antistatic Product S 546 and 10 wt% Omyafiber MB165-CBN (CaCCh-masterbatch available from Omya). Internal measurements showed that the used lot of LX530 had a melting point (peak temperature) in DSC of 161 °C and the L130 had a melting point (peak temperature) in DSC of 173 °C. Spinning temperature was 230 °C at the extruder and 235 °C at the spin beam. Draw speed was adjusted such that the fiber had an average diameter of 15-17 pm. The calender had calender temperatures of 160°C for the pattern roll and 150°C for the anvil roll and a calender pressure of 40 N/mm. The bonded pattern obtained had a bonded area of 25% and the individual areas had a diamond shape.
Part of the nonwoven fabric so obtained was dried for 24 hours at a temperature of 55 °C. The percentage of area shrinkage as a result of this drying step is shown in Table 2.
Table 1
Table 2
From Table 1 and 2 it is clear that the use of calcium carbonate in at least the sheath component of the bicomponent sheath/core fibers brings about a reduction in area shrinkage of more than 50%. These experimental data further show that the addition of a small amount of polybutylene succinate in Inventive Example 2 established a considerable further improvement in terms of area shrinkage percentage.
Claims
1. A nonwoven fabric comprising a plurality of spunbond fibers that form a nonwoven web, wherein the fibers are continuous bicomponent fibers with a core-sheath configuration in which the core component comprises a first polylactic acid (PLA1) and the sheath component comprises a second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid, wherein at least the sheath component comprises a calcium carbonate, wherein the calcium carbonate is present in the sheath component in an amount which is in the range of from 0.5-30 wt%, based on the total weight of the sheath component, wherein the nonwoven web has a side with a surface having a bonded area, and wherein the bonded area is more than 9% of the total surface of the side.
2. A nonwoven fabric according to claim 1, wherein the core component is present in an amount in the range of from 50-90 wt% and the sheath component is present in an amount of from 10-50 wt%, both based on total weight of the fibers.
3. A nonwoven fabric according to claim 1 or 2, wherein the first polylactic acid (PLA1) has a higher melting temperature than the second polylactic acid (PLA2).
4. A nonwoven fabric according to claim 1 or 2, wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same polylactic acid.
5. A nonwoven fabric according to any one of claims 1-3, wherein the first polylactic acid (PLA1) has a melting temperature in the range of from 165-180 °C, and the second polylactic acid (PLA2) has a melting temperature in the range of from 150-164 °C.
6. A nonwoven fabric according to any one of claims 1-5, wherein the calcium carbonate is present in both the core component and the sheath component, and wherein the total amount of the calcium carbonate present in the fibers is in the range of from 0.5-30 wt%, based on the total weight of the fibers.
7. A nonwoven fabric according to claim 6, wherein the calcium carbonate- containing component is present in an amount of up to 20 wt%, based on the total weight of the fibers.
8. A nonwoven fabric according to any one of claims 1-7 wherein the calcium carbonate is present in the sheath component in an amount in the range of 5-20 wt%, based on total weight of the sheath component.
9. A nonwoven fabric according to any one of claims 1-8, wherein the bonded area is between 50-100% of the total surface area of the side.
10. A nonwoven fabric according to any one of claims 1-9, wherein at least one of the core component and the sheath component comprises at least one secondary alkane sulfonate.
11. A nonwoven fabric according to any one of claims 1-10, wherein the sheath component comprises in addition at least one polybutylene succinate-based polyester which is present in an amount in the range of from 0.02-5% by weight, based on the total weight of the fibers.
12. A process for preparing a nonwoven fabric, the process comprising the following steps:
(a) providing a stream of a molten or semi-molten first polylactic acid (PLA1);
(b) providing a stream of a molten or semi-molten second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acid;
(c) blending a calcium carbonate with at least the second polylactic acid (PLA2);
(d) forming from the streams of the first polylactic acid PLA1 and the second polylactic acid (PLA2) spunbond continuous bicomponent fibers having a core-sheath configuration in which the core component comprises the first polylactic acid PLA1 and the sheath component comprises the second polylactic acid (PLA2), wherein the first polylactic acid (PLA1) and the second polylactic acid (PLA2) are the same or different polylactic acids, wherein at least the sheath component comprises a calcium carbonate, and wherein the calcium carbonate is present in the sheath component in an amount which is in the range of from 0.5-30 wt%, based on the total weight of the sheath component; and
(e) depositing the plurality of the continuous bicomponent fibers as obtained in step (d) onto a collection surface; and
(f) bonding the plurality of continuous bicomponent fibers as obtained in step (e) to obtain the nonwoven fabric comprising a nonwoven web having a side with a surface having a bonded area which is more than 9% of the total surface of the side.
13. A process according to claim 12, wherein in step (f) the bonding is carried out so as to obtain a nonwoven having a side with a surface with a bonded area which is between 50-100% of the total surface of the side.
14. An article comprising the nonwoven fabric according to any one of claims 1- 11.
15. An article according to claim 14, wherein the article comprises a diaper, a sanitary pad, a container or cover for use in respect of plants and/or agriculture applications, a packaging material, a bag or pouch.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP23209180 | 2023-11-10 | ||
| EP23209180.1 | 2023-11-10 |
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| WO2025098942A1 true WO2025098942A1 (en) | 2025-05-15 |
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| Application Number | Title | Priority Date | Filing Date |
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| PCT/EP2024/081095 Pending WO2025098942A1 (en) | 2023-11-10 | 2024-11-05 | Nonwoven fabric and process for forming the same |
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Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3338992A (en) | 1959-12-15 | 1967-08-29 | Du Pont | Process for forming non-woven filamentary structures from fiber-forming synthetic organic polymers |
| US3692613A (en) | 1970-06-10 | 1972-09-19 | Du Pont Canada | Apparatus for sealing and cutting layers of thermoplastic film |
| US3802817A (en) | 1969-10-01 | 1974-04-09 | Asahi Chemical Ind | Apparatus for producing non-woven fleeces |
| US3849241A (en) | 1968-12-23 | 1974-11-19 | Exxon Research Engineering Co | Non-woven mats by melt blowing |
| US4405297A (en) | 1980-05-05 | 1983-09-20 | Kimberly-Clark Corporation | Apparatus for forming nonwoven webs |
| EP0569153A2 (en) | 1992-05-08 | 1993-11-10 | Showa Highpolymer Co., Ltd. | Polyester resin composition |
| US5525706A (en) | 1992-10-02 | 1996-06-11 | Cargill, Incorporated | Melt-stable lactide polymer nonwoven fabric and process for manufacture thereof |
| US5665300A (en) | 1996-03-27 | 1997-09-09 | Reemay Inc. | Production of spun-bonded web |
| US5814349A (en) | 1996-05-21 | 1998-09-29 | Reifenhauser Gmbh & Co. Maschinenfabrik | Apparatus for the continuous production of a spun-bond web |
| US6506873B1 (en) | 1997-05-02 | 2003-01-14 | Cargill, Incorporated | Degradable polymer fibers; preparation product; and, methods of use |
| EP1432860A1 (en) | 2001-08-31 | 2004-06-30 | BBA Nonwovens Simpsonville, Inc. | Method of making a bonded nonwoven web |
| US6807973B2 (en) | 2001-05-04 | 2004-10-26 | Mark Vii Equipment Llc | Vehicle wash apparatus with an adjustable boom |
| US20110028062A1 (en) * | 2008-02-14 | 2011-02-03 | Chester Stephen O | Bicomponent fibers, textile sheets and use thereof |
| WO2017101974A1 (en) * | 2015-12-14 | 2017-06-22 | Ahlstrom Corporation | Polylactic acid-fibers based non-woven, method for manufacturing thereof and its use for making coffee and/or capsules in percolating apparatus |
| EP3500700B1 (en) | 2016-08-16 | 2021-01-27 | Fitesa Germany GmbH | Nonwoven fabrics comprising polylactic acid having improved strength and toughness |
| US20220178059A1 (en) * | 2017-04-26 | 2022-06-09 | Fitesa (China) Airlaid Company Limited | Airlaid composite sheet material |
| US20230087539A1 (en) * | 2020-04-01 | 2023-03-23 | Kimberly-Clark Worldwide, Inc. | Elastic Bicomponent Fiber Having Unique Handfeel |
-
2024
- 2024-11-05 WO PCT/EP2024/081095 patent/WO2025098942A1/en active Pending
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3338992A (en) | 1959-12-15 | 1967-08-29 | Du Pont | Process for forming non-woven filamentary structures from fiber-forming synthetic organic polymers |
| US3849241A (en) | 1968-12-23 | 1974-11-19 | Exxon Research Engineering Co | Non-woven mats by melt blowing |
| US3802817A (en) | 1969-10-01 | 1974-04-09 | Asahi Chemical Ind | Apparatus for producing non-woven fleeces |
| US3692613A (en) | 1970-06-10 | 1972-09-19 | Du Pont Canada | Apparatus for sealing and cutting layers of thermoplastic film |
| US4405297A (en) | 1980-05-05 | 1983-09-20 | Kimberly-Clark Corporation | Apparatus for forming nonwoven webs |
| EP0569153A2 (en) | 1992-05-08 | 1993-11-10 | Showa Highpolymer Co., Ltd. | Polyester resin composition |
| US5525706A (en) | 1992-10-02 | 1996-06-11 | Cargill, Incorporated | Melt-stable lactide polymer nonwoven fabric and process for manufacture thereof |
| US5665300A (en) | 1996-03-27 | 1997-09-09 | Reemay Inc. | Production of spun-bonded web |
| US5814349A (en) | 1996-05-21 | 1998-09-29 | Reifenhauser Gmbh & Co. Maschinenfabrik | Apparatus for the continuous production of a spun-bond web |
| US6506873B1 (en) | 1997-05-02 | 2003-01-14 | Cargill, Incorporated | Degradable polymer fibers; preparation product; and, methods of use |
| US6807973B2 (en) | 2001-05-04 | 2004-10-26 | Mark Vii Equipment Llc | Vehicle wash apparatus with an adjustable boom |
| EP1432860A1 (en) | 2001-08-31 | 2004-06-30 | BBA Nonwovens Simpsonville, Inc. | Method of making a bonded nonwoven web |
| US20110028062A1 (en) * | 2008-02-14 | 2011-02-03 | Chester Stephen O | Bicomponent fibers, textile sheets and use thereof |
| WO2017101974A1 (en) * | 2015-12-14 | 2017-06-22 | Ahlstrom Corporation | Polylactic acid-fibers based non-woven, method for manufacturing thereof and its use for making coffee and/or capsules in percolating apparatus |
| EP3500700B1 (en) | 2016-08-16 | 2021-01-27 | Fitesa Germany GmbH | Nonwoven fabrics comprising polylactic acid having improved strength and toughness |
| US20220178059A1 (en) * | 2017-04-26 | 2022-06-09 | Fitesa (China) Airlaid Company Limited | Airlaid composite sheet material |
| US20230087539A1 (en) * | 2020-04-01 | 2023-03-23 | Kimberly-Clark Worldwide, Inc. | Elastic Bicomponent Fiber Having Unique Handfeel |
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