CN120936764A

CN120936764A - Comprising cellulose filaments hydroentangled nonwoven

Info

Publication number: CN120936764A
Application number: CN202380096360.3A
Authority: CN
Inventors: A·尼尔斯特兰德; M·斯特兰德奎斯特; B·潘
Original assignee: Aishirui Health Products Co ltd
Current assignee: Aishirui Health Products Co ltd
Priority date: 2023-04-26
Filing date: 2023-04-26
Publication date: 2025-11-11
Also published as: WO2024223041A1; MX2025012513A; AU2023444996A1; CO2025014533A2

Abstract

A hydroentangled nonwoven fabric comprising synthetic cellulose filaments, natural cellulose fibers, and synthetic staple fibers. The synthetic staple fibers have a length of 10 mm to 20 mm. A wipe comprising the hydroentangled nonwoven fabric. A method of manufacturing a nonwoven fabric wherein a web of synthetic cellulose filaments is provided, and natural cellulose fibers and synthetic staple fibers are wet-formed on top of the web of synthetic cellulose filaments to form a fiber web comprising the synthetic cellulose filaments, natural cellulose fibers, and synthetic staple fibers. The fiber web is then hydroentangled to form a nonwoven fabric. A method of manufacturing a wipe.

Description

Comprising cellulose filaments hydroentangled nonwoven

Technical Field

The present invention relates to hydroentangled nonwoven comprising man-made cellulose filaments, wipes comprising such hydroentangled nonwoven, methods of making nonwoven and methods of making wipes.

Background

Absorbent nonwoven materials are commonly used to wipe various spills and leaks in industrial, service, office, and home settings. There are many demands for making nonwoven materials for wiping purposes. The desired wipe should be strong, absorbent, abrasion resistant and exhibit low pile. To meet these needs, absorbent nonwoven materials typically include different types of fibers, such as combinations of fiber filaments and staple fibers, as well as fibers of different sources, such as fossil-based plastic fibers and/or natural fibers. After materials other than fossil or plastic-free materials are desired, man-made cellulose fibers (commonly referred to as regenerated cellulose fibers) have been considered as components of absorbent nonwoven materials.

WO 2018/184042 discloses a nonwoven material for industrial cleaning wipes. The nonwoven material comprises a cellulosic nonwoven web made of substantially pure cellulose formed from continuous filaments. The nonwoven material may comprise layers formed of substantially continuous filaments, pulp fibers, or staple fibers, all of which are subsequently hydroentangled together. A method for making a nonwoven material comprised of substantially continuous cellulose filaments is also disclosed.

WO 2005/042819 discloses a hydroentangled nonwoven material comprising continuous filaments, natural fibers and staple fibers. A method of making the nonwoven material is also disclosed. The method includes forming a fibrous web of continuous filaments on a forming fabric and applying a wet-formed fibrous dispersion comprising staple fibers and natural fibers on top of the continuous filaments and then hydroentangling the fibrous web.

Disclosure of Invention

It is an object of the present invention to provide strength, in particular wet strength, to nonwoven materials comprising man-made cellulosic fibres.

This object, as well as other objects that will be apparent to those skilled in the art upon studying this specification, is achieved by the hydroentangled nonwoven, wipe, and method of the appended claims.

It has thus been found that staple fibers having a length of 10 to 20mm, preferably 10 to 15mm, are advantageous in providing strength to a hydroentangled nonwoven comprising staple cellulose filaments and wood pulp fibers. Thus a high ratio of wet to dry tensile index can be obtained, although cellulose-based nonwovens generally have much lower such ratios than nonwovens based on synthetic or fossil materials.

In a first aspect, the present invention relates to a hydroentangled nonwoven comprising staple cellulosic filaments, natural cellulosic fibers and staple fibers, wherein the staple fibers have a length of from 10 to 20mm, preferably from 10 to 15mm.

Staple fibers are cut lengths of natural fibers or from synthetic filaments. Staple fibers for nonwovens typically have a length of 5 to 60mm, such as 20 to 60mm or 40 to 60mm. Staple fibers include staple fibers (also referred to as chopped fibers) having a length of less than 20mm or less than 15 mm. Filaments are generally very long fibers proportional to their diameter, in principle infinite. Filaments include fibers that are the result of the filaments breaking during manufacture or web formation.

The hydroentangled nonwoven may comprise from 10 to 50 weight percent of the man-made cellulosic filaments, from 20 to 85 weight percent of the natural cellulosic fibers, and from 2.5 to 25 weight percent of the man-made staple fibers, the weight percentages being based on the total weight of the nonwoven. Alternatively, the hydroentangled nonwoven may comprise 15 to 35 weight percent of man-made cellulosic filaments, 40 to 75 weight percent of natural cellulosic fibers, and 5 to 20 weight percent of man-made staple fibers, the weight percentages being based on the total weight of the nonwoven.

The man-made cellulose filaments may be formed from cellulose of natural origin, such as regenerated cellulose. Regenerated cellulose is obtained by converting natural cellulose into soluble cellulose derivatives and subsequently regenerating the cellulose, typically forming fibers or filaments. Examples of regenerated cellulose are rayon, viscose, lyocell and acetate. The use of cellulose filaments formed from cellulose of natural origin helps to provide a biobased or non-fossil nonwoven. Preferably, the natural cellulose is not chemically modified. Examples of natural cellulose that is not chemically modified are viscose or lyocell, preferably lyocell. The use of cellulose filaments formed from natural cellulose that have not been chemically modified further helps to provide a plastic-free nonwoven. Generally, man-made cellulose filaments may comprise a plurality of filament types.

The rayon filaments are preferably solution blown filaments. WO 2018/184042 discloses a method for manufacturing a nonwoven material consisting of substantially continuous cellulose filaments. The method includes preparing a cellulose-containing spinning solution, such as cellulose dissolved in N-methylmorpholine N-oxide (NMMO), extruding the spinning solution through a spinneret, attenuating the extruded spinning solution using a high velocity air stream, forming a web on a moving surface, and washing and drying the web. During attenuation and/or web formation, a coagulation liquid is applied which is capable of causing the dissolved cellulose to coagulate. The process is described as being similar or analogous to the "melt blowing" process used to produce synthetic thermoplastic fibers. When cellulose is dissolved in a solution (i.e., not a molten thermoplastic) and the spinning and air temperatures are only moderately elevated, the disclosed process is referred to as "solution blowing".

The natural cellulosic fibers may be pulp fibers, such as wood fibers. Wood fibers are particularly suitable for use. Both softwood fibers and hardwood fibers are suitable. Recycled wood fibers may also be used. The fiber length will vary from about 3mm for softwood fibers to about 1.2mm for hardwood and may be even shorter for recycled fibers. Many other types of natural fibers may also be used, particularly those having water absorbing capacity and a tendency to contribute to the creation of coherent sheets. Examples of other natural cellulosic fibers are seed hair fibers, such as cotton, kapok or marigold, leaf fibers, such as sisal, abaca, pineapple or new zealand hemp, and bast fibers, such as flax, hemp, jute or kenaf. Natural cellulosic fibers can be derived from a number of natural sources.

The staple fibers may be formed from polyethylene, polypropylene, polyester, polyamide, polylactide, polyhydroxyalkanoate, or cellulose, preferably from polylactide, polyhydroxyalkanoate, or cellulose, more preferably from cellulose. The use of short fibers formed from polylactide, polyhydroxyalkanoate, or cellulose helps provide a bio-based or non-fossil and biodegradable and compostable nonwoven. The staple fibers may be formed from bio-based polyethylene, bio-based polypropylene, bio-based polyester, or bio-based polyamide. The use of staple fibers formed from bio-based polyethylene, bio-based polypropylene, bio-based polyester or bio-based polyamide helps provide a bio-based or non-fossil nonwoven. In addition, the staple fibers may be formed from cellulose of natural origin, such as regenerated cellulose. Examples of regenerated cellulose are rayon, viscose, lyocell and acetate. The use of staple fibers formed from cellulose of natural origin helps provide a biobased or non-fossil nonwoven. Preferably, the natural cellulose is not chemically modified. Examples of natural cellulose that is not chemically modified are viscose or lyocell, preferably lyocell. The use of staple fibers formed from natural cellulose that has not been chemically modified further helps to provide a plastic-free nonwoven. Generally, staple fibers can comprise a variety of fiber types.

If the man-made cellulose filaments and staple fibers are formed from natural cellulose that has not been chemically modified, more preferably from viscose or lyocell fibers, most preferably from lyocell fibers, a nonwoven may be provided that is free of plastics. The cellulose filaments and staple fibers can be formed from the same natural cellulose that has not been chemically modified or from different natural celluloses that have not been chemically modified, respectively.

The hydroentangled nonwoven may have a basis weight of from 20 to 200g/m ², preferably from 40 to 120g/m ².

In a second aspect, the present invention relates to a wipe comprising a hydroentangled nonwoven as disclosed herein. The wipe is a disposable cloth for cleaning the wiping object. The wipe may be provided as a discrete sheet or as a roll of wiping material from which a sheet of suitable length may be torn off.

The wipe may be a wet wipe, such as a wipe that also contains a liquid formulation. The liquid formulation may comprise a cleaning agent, a disinfectant and/or a soothing agent.

In a third aspect, the invention relates to a method of manufacturing a nonwoven, wherein a web of man-made cellulose filaments is provided and natural cellulose fibers and man-made staple fibers are wet formed on top of the web of man-made cellulose filaments, thereby forming a fibrous web comprising the man-made cellulose filaments, natural cellulose fibers and man-made staple fibers, and the fibrous web is then hydroentangled to form a nonwoven, wherein the man-made staple fibers have a length of 10mm to 20mm, preferably 10mm to 15 mm.

Hydroentanglement or spunlacing is described in CA841 938. Hydroentanglement involves the formation of a fibrous web, after which the filaments and fibers are entangled by very fine water jets under high pressure. Several drainage jets are directed to the fibrous web supported by the movable fabric.

Typically, a fiber dispersion comprising natural cellulosic fibers and man-made staple fibers may be wet formed onto the top of the man-made cellulosic filament web. Thus, wet forming of natural fibers and staple fibers on top of the web can be performed in a single operation.

Staple fibers may be foam formed onto the top of the man-made cellulosic filament web. Foam forming of the fibers aids in uniform forming. Short fibers having a length of 10mm to 20mm are otherwise difficult to uniformly distribute, especially when dispersed with natural fibers.

Hydroentanglement of foam formed fibrous webs is disclosed in WO 96/02701. Foam forming is a special variant of wet-laid in which water in addition to the fibres and chemicals also contains surfactants which make it possible to produce foam in which the fibres can be embedded in and between the foam bubbles. The fibers may be pulp fibers and other natural and synthetic fibers.

The web of man-made cellulose filaments may be provided by extruding a cellulose-containing solution through a spinneret onto a moving surface, for example by solution blowing of the cellulose-containing solution. Alternatively, the web of man-made cellulose filaments may be provided as a pre-formed web, such as a web material roll. Preferably, the web of man-made cellulose filaments has a basis weight of 2 to 50g/m ², preferably 15 to 40g/m ².

Additives such as wet strength agents, adhesive chemicals, latex, debonding agents, and the like may be added during the manufacture of the nonwoven.

The method of making the nonwoven may also be characterized as set forth for the hydroentangled nonwoven disclosed herein.

In a fourth aspect, the present invention relates to a method of making a wipe comprising a method of making a nonwoven as described herein, wherein the nonwoven is further cut, perforated, folded, microcreped, calendered, embossed, printed and/or provided with a liquid formulation.

The method of making the wipe may also be characterized as set forth for the wipes disclosed herein.

Drawings

Fig. 1 schematically illustrates an exemplary production line for making a hydroentangled nonwoven according to the present invention.

Detailed Description

With reference to fig. 1, an exemplary production line for making a hydroentangled nonwoven fabric according to the present invention will be described. The line is formed along an endless forming fabric 1, with man-made cellulose filaments 2 laid down on the endless forming fabric 1, and excess air is drawn through the endless forming fabric 1. The web 3 of resulting man-made cellulose filaments is advanced to a wet-laid stage 4 where a foam comprising wood pulp fibers 5 and staple fibers 6 is wet-laid on top of the web 3 and where excess water is drained through the forming fabric 1. The resulting web comprising the man-made cellulosic filaments, wood pulp fibers and staple fibers is advanced to a hydroentanglement stage 7 where the filaments and fibers are combined by the action of a plurality of fine high pressure water jets impacting the web to form a nonwoven 8, and where the hydroentangled water is discharged through the forming fabric 1.

The resulting nonwoven 8 is advanced to a drying stage (not shown) in which the nonwoven 8 is dried and further advanced to a stage (not shown) for rolling, cutting, packaging, etc.

According to the embodiment shown in fig. 1, filaments 2 are laid directly on forming fabric 1 where they are allowed to form web 3.

Air for drawing and stretching the filaments is drawn through the forming fabric 1 so that the filaments 2 follow the air flow into the web of the forming fabric to stay there.

When the filaments 2 are laid down on the forming fabric 1, the speed of the filaments 2 is much higher than that of the forming fabric, so that the filaments will form irregular loops and bends as they are collected on the forming fabric to form a very randomized web 3.

The wood pulp fibers 5 and the staple fibers 6 are pulped in a conventional manner, mixed together or first separately and then mixed, and conventional papermaking additives such as wet and/or dry strength agents, retention aids and/or dispersants are added to produce a well-mixed slurry of wood pulp fibers and staple fibers in water. The mixture is pumped through a wet-laid headbox 4 onto a moving forming fabric 1 where it is laid on a web 3. Excess water is drawn through the web 3 of filaments 2 laid on the forming fabric 1 and down through the forming fabric by a suction box arranged below the forming fabric.

The web 3 of filaments 2, wood pulp fibers 5, and staple fibers 6 is hydroentangled while still supported by the forming fabric 1. In the hydroentanglement stage 7, the different filament and fiber types are hydroentangled and a composite nonwoven 8 is obtained. The hydroentangling stage 7 may comprise several transverse bars with rows of nozzles from which very fine water jets are directed against the web 3 under very high pressure to provide hydroentanglement of filaments and fibres. The water jet pressure may be adapted to provide specific pressure profiles with different pressures in different rows of nozzles. Alternatively or subsequently, the web 3 may be transferred to a separate hydroentangled fabric (not shown) where (further) hydroentanglement takes place.

The drying stage (not shown) may be carried out on conventional web drying equipment, preferably of the type used for tissue drying, such as through-air drying or yankee drying. After drying, the material is typically wound into a parent roll prior to conversion.

The material is then converted into a suitable form and packaged in a known manner.

The invention is not limited to the embodiments or examples shown in the drawings or described herein, but may be further modified within the scope of the claims.

Example

By mixing wood pulpPlus Fluff Pulp, southern softwood Fluff from International Paper) or a dispersion of wood Pulp and lyocell staple fibers (1.7 dtex) was foam formed onto a web of solution blown lyocell filaments to make a nonwoven in a Formette sheet former. Different lengths of lyocell staple fibers were applied to three different webs of solution blown lyocell filaments as shown in tables 1, 2 and 3, respectively.

The nonwoven was then hydroentangled on one side of the web with 10 manifold/jet strips, 120 of which had entangling nozzle hole diameters of 120 μm with a spacing between holes of 0.8mm.

For the web of solution blown lyocell filaments and the hydroentangled nonwoven, basis weight (measured according to NWSP.1.r0 (15)) and thickness (measured according to NWSP 120.6R0 (15)) as well as dry and wet tensile properties (measured according to NWSP 110.4R1 (22), 50mm wide strips, grip distance 50mm, constant extension rate, test speed 100mm/min, wet to saturation applied for wet tensile properties) were obtained as shown in tables 1, 2 and 3.

The tensile index as used in this specification is calculated according to the following formula:

X ₂ -tensile index (Nm/g)

X _1MD -MD tensile Strength (N/m)

X _1CD -CD tensile Strength (N/m)

G ₁ -basis weight (g/m ²)

To facilitate evaluation of the effect of staple fiber length and staple fiber content on nonwoven strength, the percent increase in dry and wet tensile properties of the nonwoven material containing staple fibers was calculated relative to the tensile properties of the nonwoven without staple fibers. The data obtained are shown in tables 4 and 5.

Table 1 preparation of first solution blown webs and hydroentangled nonwoven fabrics

Table 2 preparation of second solution blown webs and hydroentangled nonwoven fabrics

Table 3 preparation of third solution blown web and hydroentangled nonwoven fabric

TABLE 4 influence of staple length on nonwoven strength (percent increase relative to sample without staple)

TABLE 5 influence of staple content on nonwoven Strength (percentage increase relative to sample without staple)

Claims

1. A hydroentangled nonwoven article, comprising the following steps:

A filament of an artificial cellulose is provided,

Natural cellulose fibers, and

The artificial short fiber is made of a synthetic fiber,

Wherein the staple fibers have a length of 10mm to 20mm, preferably 10mm to 15 mm.

2. The hydroentangled nonwoven fabric according to claim 1, comprising:

from 10 to 50% by weight of man-made cellulose filaments,

20 To 85% by weight of natural cellulose fibers, and

2.5 To 25% by weight of staple fibers,

The weight percentages are based on the total weight of the nonwoven.

3. The hydroentangled nonwoven fabric according to claim 2, comprising:

15 to 35% by weight of man-made cellulose filaments,

40 To 75% by weight of natural cellulose fibers, and

From 5 to 20% by weight of staple fibers,

The weight percentages are based on the total weight of the nonwoven.

4. The hydroentangled nonwoven according to any of the preceding claims, wherein the man-made cellulose filaments are formed from cellulose of natural origin, preferably from natural cellulose that has not been chemically modified, more preferably from viscose or lyocell, most preferably from lyocell.

5. The hydroentangled nonwoven according to any of the preceding claims, wherein said staple fibers are formed from polyethylene, polypropylene, polyester, polyamide, polylactide, polyhydroxyalkanoate or cellulose, preferably from polylactide, polyhydroxyalkanoate or cellulose, more preferably from cellulose.

6. The hydroentangled nonwoven according to claim 5, wherein the staple fibers are formed from cellulose of natural origin, preferably from natural cellulose that has not been chemically modified, more preferably from viscose or lyocell, most preferably from lyocell.

7. The hydroentangled nonwoven according to any one of claims 4 to 6, wherein the man-made cellulose filaments and the man-made staple fibers are formed from natural cellulose that has not been chemically modified, more preferably from viscose or lyocell, most preferably from lyocell.

8. A wipe comprising the hydroentangled nonwoven according to any one of claims 1 to 7.

9. The wipe of claim 8, wherein the wipe is a wet wipe, such as a wipe further comprising a liquid formulation.

10. A method of making a nonwoven article, wherein

Providing a web of man-made cellulose filaments, and

Natural cellulose fibers and staple fibers are wet formed on top of the web of staple cellulose filaments,

Thus forming a fibrous web comprising said man-made cellulose filaments, natural cellulose fibers and man-made staple fibers, and

The fibrous web is then hydroentangled to form a nonwoven,

11. The method of claim 10, wherein a fiber dispersion comprising the natural cellulose fibers and the staple fibers is wet formed on top of the web of staple cellulose filaments.

12. The method of claim 10 or 11, wherein the staple fibers are foam formed on top of the web of staple cellulose filaments.

13. The method according to any one of claims 10 to 12, wherein the web of man-made cellulose filaments is provided by extruding a cellulose-containing solution through a spinneret onto a moving surface, such as by solution blowing of the cellulose-containing solution.

14. The method according to any one of claims 10 to 13, further characterized by the method according to any one of claims 2 to 7.

15. A method of manufacturing a wipe comprising the method according to any of claims 10 to 14, wherein the nonwoven is further cut, perforated, microcreped, calendered, embossed, printed and/or provided with a liquid formulation.