CN1615380A - High elongation, low denier fibers using high extrusion rate spinning - Google Patents

Abstract

Low denier, high extensibility fibers, soft extensible nonwoven webs comprising such fibers, and disposable articles comprising such nonwoven webs can all be obtained by spinning the polymer composition through small diameter holes.

Description

High elongation, low denier fibers spun with high extrusion rates

field of invention

The present invention relates to low denier, high extensibility fibers, soft extensible nonwoven webs comprising these fibers, and disposable articles comprising such nonwoven webs.

Background of the invention

Nonwoven webs formed by nonwoven extrusion processes such as meltblown and spunbond can be made into products and product components that are so inexpensive to manufacture that they can be considered for one-time or few-use applications. disposable products. Representative examples of such products include disposable absorbent articles such as diapers, incontinence briefs, training pants, feminine hygiene underwear, wipes, and the like.

Consumers demand that nonwoven materials used in disposable products deliver softness and stretch. Softer nonwoven materials are gentler on the skin and provide a more garment-like aesthetic to the diaper. Nonwovens with high extensibility under relatively low external forces can be used to provide products such as disposable diapers with consistent conformability, for example as part of stretch composites, and for the use of different mechanical post-treatments such as Stretching, piercing and more for convenience. A ductile substance is defined herein as one that can elongate, but not necessarily recover all or some of the applied strain. Elastic materials, by definition, must recover most of their elongation after unloading.

Several different methods have been used in the art to make extensible nonwoven materials:

World Patent Application WO 00/04215 discloses a specific bonding pattern designed for the production of high extensibility nonwovens, in particular for sheath-core polypropylene staple fibers. The bond pattern has bond locations staggered in adjacent rows such that they do not overlap in the manufacturing machine direction (MD). Preferably the nodes are quadrangular in shape and cover less than 20% of the entire bonding area. They disclose that the fibers do not bond at 35-55° to the machine direction, thus allowing greater transverse elongation for fabrication.

Fiber formulations are often used to achieve ductility. U.S. Patents 5,804,286 and 5,921,973 disclose blends of polyethylene and polypropylene, with or without miscible ethylene-propylene copolymers, which produce soft, high-strength non-woven material. World patent application WO 00/31385 discloses polypropylene and ethylene copolymer blends, and U.S. Patent 6,015,317 discloses blends of two different ethylene polymers, both of which improve bonding and fabric elongation while maintaining good spinning performance. U.S. Patent 5,616,412 discloses filaments of polypropylene and higher molecular weight polypropylene (2-4 denier per fiber), filaments having both exhibit higher elongation than polypropylene alone sex. US Patent 5,322,728 discloses soft nonwoven materials comprising ethylene copolymers with good extensibility, whereas US Patent 4,769,279 discloses soft nonwoven materials comprising ethylene acrylic acid copolymers having good extensibility. US Patents 4,804,577 and 4,874,447 disclose extensible meltblown nonwoven materials comprising blends of polyolefins, isoolefins, and elastomeric copolymers of conjugated dienes, such as isobutylene-isoprene copolymers. U.S. Patent No. 5,349,016 discloses drawable fibers grafted with propylene polymers (such as styrene or methyl methacrylate grafted onto a polypropylene backbone), which have high flex recovery and modulus, and in some cases The elongation exceeds that of the pure polypropylene control. US Patent 6,080,818 discloses fibers of a nonwoven material comprising a blend of isotactic polypropylene and an irregularly flexible polyolefin having higher elongation than would otherwise be the case without the flexible polymer.

All of these available formulation methods can increase the extensibility of moderate to low denier fibers to some extent, but not to the extent disclosed in the present invention. Furthermore, they generally involve mixtures of higher cost materials and may involve specific mixing requirements to ensure proper distribution within the mixture.

This method of nonwoven web formation can also be used to maximize stretch properties. US Patent No. 5,494,736 discloses a high elongation carded nonwoven material from high elongation fibers placed in a more transverse orientation than conventional carded fibers. The claimed bond area is in the range of 8 to 25%.

In today's textile industry there remains an unmet need to obtain extensible nonwoven materials with moderate to low denier fibers that can be manufactured from conventional resins without the need for costly specific or elastomeric polymers. It is well known that as the spin elongation rate increases, the directionality of the molecules increases but the elongation of the fibers decreases. For high-strength low-denier fibers, this is not a problem, but producing low-denier fibers with high elongation remains a significant challenge. It is therefore an object of the present invention to disclose a method for producing low denier fibers with high elongation at break. Another object of the present invention is to disclose soft, extensible nonwoven webs comprising such low denier, high elongation fibers. Another object of the present invention is to disclose disposable articles comprising such soft extensible nonwoven webs.

Summary of the invention

The present invention discloses a method of producing low denier fibers with high elongation at break. By changing the spinneret design on the fiber row to have a small capillary diameter to maintain the desired high spinning speed, a combination of properties can be obtained, but produces moderate to low draft ratios. A particular embodiment of the invention comprises fibers having a diameter in the range of 5 to 25 microns produced by melt spinning of a polymer mixture, for example with a draw down ratio of less than 400 and a mass throughput of 0.01 to 2.0 grams per hole per minute, And the spinneret diameter is less than 200 microns. Alternative embodiments of the present invention comprise fibers having diameters in the range of 5 to 25 microns produced by melt spinning of polymer blends, e.g., draw down ratios less than 400, fiber elongation at break greater than 400%, and spinning The head diameter is less than 200 microns.

Without being limited by theory, it is believed that the lower draw down ratio results in fibers with less directionality, thus maintaining a higher residual elongation at break. Highly uniform fabrics containing fine-diameter, high-elongation fibers can be produced in this manner. Nonwoven webs with this combination of properties are especially suitable for use in disposable absorbent articles such as diapers, incontinence briefs, training shorts, feminine hygiene underwear, wipes, etc., as they can also be part of an article where extensibility and softness Sex can increase the comfort and overall performance of the article.

Figure overview

Figure 1 shows the elongation at break for melt spun polypropylene at 0.2 grams per hole per minute at 400 melt flow rate using 86 micron diameter capillaries and 570 micron diameter capillaries.

Detailed description of the invention

As used herein, the term "absorbent article" means a device that absorbs and contains bodily exudates, and more particularly, a device that is placed against or adjacent to the body of the wearer to absorb and contain various bodily exudates.

The term "disposable" as used herein refers to absorbent articles that are not intended to be laundered, restored, or reused as absorbent articles (i.e., they are designed to be discarded after a single use, preferably recycled, composted, or processing or other processing). By "unitary" absorbent articles are meant absorbent articles formed of separate parts forming a common entity and interconnected so that they do not require separate handling parts, such as a separate support and liner.

The term "nonwoven web" as used herein refers to a web having a structure of individual fibers or threads interposed, but not in any regularly repeating fashion. Nonwoven webs have been made in the past by various methods such as airlaid, meltblown, spunbonded, carded, including bonded carded.

As used herein, the term "microfibers" refers to small diameter fibers having an average diameter of no greater than about 100 microns and a length-to-diameter ratio of greater than about 10. Those trained in the art will know that the diameter of the fibers comprising a nonwoven web affects its overall softness and comfort, and that finer denier fibers generally produce a softer and more comfortable product than coarser denier fibers. For the fibers of the present invention, in order to obtain suitable softness and comfort, the preferred diameter is in the range of about 5 to 25 microns, more preferably the diameter is in the range of about 10 to 25 microns, and even more preferably the diameter is in the range of about 10 to 20 in the micron range. Fiber diameter can be determined using, for example, an optical microscope calibrated with a 10 micron count line.

The term "meltblown fibers" as used herein refers to fibers formed by extruding molten thermoplastic material through a plurality of thin, usually circular, capillary dies into molten threads or Air) flows down to elongate the filaments of molten thermoplastic material so that their diameters are reduced, even down to microfiber diameters. Thereafter, the meltblown fibers are carried by the high velocity air stream and deposited onto a collecting surface to form a web of randomly distributed meltblown fibers.

The term "spunbond fibers" as used herein refers to small diameter fibers formed by extruding molten thermoplastic material into filaments from a plurality of thin, generally circular spinnerets having the same diameter as the extruded filaments The capillary is then rapidly reduced in diameter by conventional wire winding system drawing or convective air drawing elongation. If a guide wire system is applied, the fiber diameter can also be reduced by post-extrusion drawing.

The terms "consolidated" and "consolidated" as used herein refer to the most intimate collection of at least a portion of the fibers of a nonwoven web to form a bond site or sites that are less bonded than an unconsolidated web. Positioning can increase the resistance of the nonwoven to external forces such as abrasion and tension. "Consolidated" may refer to the entirety of the nonwoven web produced by most intimately bonding at least a portion of the fibers, such as by thermal bonding. Such a web may be considered a "consolidated web". In another sense, the specific discrete regions of fibers that are most tightly bonded, such as individual thermal bond sites, can be described as "consolidated."

Consolidation can be achieved by a variety of methods including applying heat and/or pressure to the web, such as thermal position (ie, point) bonding. Thermal point bonding can be achieved by passing the web through a pressure nip formed by two rolls, one of which is heated and has a plurality of raised points on its surface, as described in the aforementioned US Patent 3,855,046 to Hansen et al. Consolidation methods may also include, but are not limited to, ultrasonic bonding, convective air bonding, resin bonding, and hydroentanglement. Hydroentanglement typically involves the use of high pressure water jets to consolidate the web by mechanical fiber entanglement (friction) in the areas to be consolidated, with bond sites formed in the areas where the fibers are entangled. Fibers may be hydroentangled as taught in the following U.S. Patents: U.S. Patent 4,021,284 issued May 3, 1977 to Kalwaites and U.S. Patent 4,024,612 issued May 24, 1977 to Contrator et al., both of which are hereby incorporated herein by reference. refer to.

While the nonwoven webs of the present invention have beneficial use as components of disposable articles such as diapers, their use is not limited to disposable absorbent articles. The nonwoven webs of the present invention can be used in any article that requires or benefits from softness and extensibility, including, for example, wipes, polishing cloths, furniture backings, durable clothing, and the like.

The extensible soft nonwoven material of the present invention may be in the form of a laminate. The laminates may be bonded using any bonding method known to those skilled in the art including, but not limited to, thermal bonding, including but not limited to spray adhesives, hot melt adhesives, latex based Adhesive bonding such as adhesives, sonic and ultrasonic bonding, and extrusion lamination, in which a polymer is cast directly on another nonwoven and bonded to the nonwoven while still partially molten One side bonding or depositing meltblown fibers directly on the nonwoven material. These and other suitable methods of making laminates are described in U.S. Patents 6,013,151 to Wu et al., issued January 11, 2000, and in U.S. Patent 5,932,497 to Morman et al., issued August 3, 1999. description, both of which are incorporated herein by reference.

The term "polymer composition" used in the present invention generally includes, but is not limited to, homopolymers, copolymers, for example in block, graft, random form and alternating copolymers, terpolymers, etc., and mixtures thereof or modifiers. Furthermore, unless specifically defined otherwise, the term "polymer composition" shall include all possible geometries of the material in question. These configurations include, but are not limited to, isotactic, syndiotactic, and random symmetries. Examples of suitable thermoplastic polymers for use in the present invention include, but are not limited to, polyethylene, polypropylene, polyethylene-polypropylene copolymers, polyvinyl alcohol, polyester, nylon, polylactide, polyhydroxy chain Alkanoates, polycondensates of aliphatic esters, and mixtures thereof. Preferred polymer compositions comprise polyolefins such as polyethylene and polypropylene, or polyesters such as poly(ethylene terephthalate), and copolymers thereof. Preferred other polyesters include, but are not limited to, poly(lactic acid) (e.g. Lacea from Mitsui Chemicals, or EcoPLA from Dow Cargill), poly(caprolactone) (e.g. ToneP787 from Union Carbide), poly(butylene succinate) (such as Showa Denko's Bionolle 1000 series), poly(ethylene succinate) (such as Nippon Shokubai's Lunare SE), poly(butylene succinate adipate) (such as Showa Denko's Bionolle 3000 series), poly( ethylene succinate adipate), aliphatic polyester-based polyurethanes (such as Morthane PN03-204, PN03-214 and PN3429-100 from Morton International), adipate copolyesters, terephthalic acid and 1,4- Butanediol (e.g. Eastar Bio from Eastman Chemical Company and Ecoflex from BASE), polyester amides (e.g. BAK series from Bayer Corporation), hydrolyzable aromatic/aliphatic copolyesters (e.g. Biomax from DuPont), cellulose esters ( Examples include cellulose acetate, cellulose acetate butyrate, and Eastman Chemical Company's cellulose acetate propionate), and combinations and copolymers thereof, and the like.

The polymer composition may also include various non-polymeric components including nucleating agents, anti-blocking agents, antistatic agents, slip agents, pre-heat stabilizers, antioxidants, oxygen-promoting additives, pigments, fillers wait. These components can be used in conventional amounts, but in order to obtain the favorable combination of softness and extensibility, these additives are generally not required in the composition.

Those skilled in the art will appreciate that the melt flow rate of the polymer composition is appropriate for the fiber manufacturing process of interest, such as melt spinning or melt blowing. The melt flow rate of a polymer composition can be determined using, for example, the method outlined in ASTM D1238.

The term "extensible" as used herein means that any fiber can be elongated by at least about 400% without catastrophic failure, more preferably at least 600% without catastrophic failure, even More preferably at least 800% can be stretched without catastrophic failure. Elongation at break can be determined using, for example, the method outlined in ASTM D3822 and is defined as the elongated length at break minus the initial test gauge length divided by the initial test gauge length times 100.

Continuous fibers, staple fibers, hollow fibers, shaped fibers such as multilobal fibers and multicomponent fibers can all be prepared by using the method of the present invention. Herein, a component is defined as a separate portion of a fiber that has a spatial relationship with another portion of the fiber. Multicomponent fibers, usually bicomponent fibers, may be in side-by-side, sheath-core, segmented pie, ribbon, or star-like configurations. The sheath may surround the core continuously or discontinuously. Fibers of the present invention can have different geometries, including circular, oval, star, rectangular, and various other eccentric shapes. The fibers of the present invention may also be split fibers. Disintegration can occur due to differences in the rheological properties of the polymers, as well as mechanically and/or fluid-induced deformation. As used herein, the diameter of a fiber of non-circular cross-section is the equivalent diameter of a circle having the same cross-sectional area.

In conventional melt spinning processes, fiber velocity and spinning speed can mostly be calculated using the continuity equation:

Where V _x is the total fiber velocity, Q is the mass output of each spinneret hole, ρ _fiber is the density of the fiber, and d is the diameter (or equivalent diameter) of the fiber. The total fiber velocity consists of two main components

(2) V _x =V _o +V _A

where V _o is the velocity at which the fiber is withdrawn from the spinneret, and V _A is the apparent velocity of the fiber associated with filament elongation. The most significant influences on determining _VA are inertial, drag and rheological forces. V _A force is the force that creates direction in the filament.

The withdrawal rate of the fiber can be calculated according to Equation 3 and depends only on Q and the diameter (or equivalent diameter) of the capillary D

where density ρmelt is in this case the polymer melt density. For a given Q, D is the only variable, so the withdrawal rate depends only on the diameter of the capillary tube.

Higher fiber elongation velocity V _A results in higher orientation of the fibers and produces small diameter fibers with higher strength but lower elongation. Without being bound by theory, for high elongation fibers it is desirable to maintain a low degree of directionality in the fiber while maintaining a moderate to small diameter for comfort and softness. In other words, the elongation rate V _A = V _x - V _o , or alternatively, the draw ratio V _x /V _o should be low. To maintain small diameter fibers for uniformity, coverage and softness, this generally requires a reduction in output Q. However, this reduces the overall yield of material, leading to a less than satisfactory economic impact. Generally, a mass output of about 0.01 grams per minute per well is considered a minimum for those trained in the art. It is also understood by those trained in the art that mass throughput greater than about 2.0 grams per hole per minute can lead to flow instabilities in the mold, eg, melt fracture or wall slippage, resulting in difficulties in handling or collecting product of suitable quality. Thus, preferably the mass output is in the range of 0.01 to 2.0 g/min/hole, more preferably 0.2 to 1.0 g/min/hole, even more preferably 0.6 to 0.8 g/min/hole. The mass yield per hole can be determined, for example, by collecting the extrudate for a given time and then dividing the value of the total mass collected by the collection time interval by the number of holes in the spinneret from which the fiber is drawn.

Using the method of the present invention, increasing the fiber velocity as the fiber is drawn out of the spinneret capillary ( _Vo ) reduces the draw ratio _Vx / _Vo or the elongation rate _VA without reducing the throughput. This can be accomplished by using smaller capillary diameters. The following formulas give typical spin numbers that are useful throughout most of this disclosure.

$<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}}<span\; class="notranslate">\; )</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}}{\mathrm{<span\; class="notranslate">\; Q</span>}}$

Similar to the draft ratio, lower values of the spin number _Sx are preferred.

Without being limited by the examples, for example, for a given mass output of 0.52 g/min/hole (typical for conventional high speed melt spinning systems), and a standard capillary diameter of 0.6 mm, melt spinning grade poly The withdrawal rate _Vo of the propylene filaments will be about 2.5 m/min. Generally, in order to produce a good uniform nonwoven fabric, a conventional high speed melt spinning system must be operated at a fiber velocity V _x equal to or higher than about 2000 m/min, then the draw ratio V _x /V _o will be about 800, the spin count _Sx would be approximately 7980 microns/(g/min/hole), the nonwoven properties associated with this fiber (eg, high directionality and low elongation). For the same spinning conditions, if instead using a capillary diameter of 0.07 mm, the filament withdrawal rate would be high at about 183 m/min, _Vx / _Vo would be much lower at about 11, _Sx It will be much lower at about 403 microns/(g/min/pore). The resulting fibers will have lower orientation and higher residual elongation.

Those trained in the art will appreciate that the diameter of the fibers comprising the nonwoven web affects overall softness and comfort, and that products produced with fine fibers are generally softer and more comfortable than products produced with coarse fibers. For the fibers of the present invention, in order to obtain suitable softness and comfort, the preferred diameter is in the range of about 5 to 25 microns, more preferably the diameter is in the range of about 10 to 25 microns, and even more preferably the diameter is in the range of about 10 to 20 in the micron range. To maintain small diameter fibers for uniformity, coverage and softness, this would routinely require a reduction in output Q. However, this would reduce the overall output of material, leading to a less than satisfactory economic impact. Generally, a mass output of about 0.01 g/min/hole is considered a minimum for those trained in the art. Those trained in the art will further appreciate that mass output greater than about 2.0 grams per hole per minute can lead to flow instabilities in the mold, e.g., melt fracture or wall slippage, resulting in difficulties in handling or collecting product of suitable quality . Thus, preferably the mass output is in the range of 0.01 to 2.0 g/min/hole, more preferably in the range of 0.2 to 1.0 g/min/hole, even more preferably in the range of 0.6 to 0.8 g/min/hole . Furthermore, those trained in the art will appreciate that to obtain a good uniform nonwoven web on older melt spinning systems, the fiber velocity V _x must typically be greater than about 500 m/min, on the newer moderate speed On systems, fiber velocities typically must be greater than about 2000 meters per minute, and on newer high speed spinning systems, fiber velocities must generally be greater than about 3000 meters per minute.

Furthermore, it will be further appreciated by those with special training in the art that lower draft ratios _Vx / _Vo will generally result in higher remaining fiber elongation at break. We have found that draft ratios of less than about 400 are generally sufficient to produce fibers having an elongation at break suitable for making the soft, extensible nonwoven materials of the present invention, more preferably a draw ratio of less than about 150, and even more preferably a draw ratio of The stretch ratio is less than about 50. To achieve these low draw down ratios and high fiber velocities within the scope of the present invention, we have found that spinneret diameters of less than about 200 microns are generally sufficient, more preferably spinneret diameters of less than about 150 microns are even more preferred The head diameter is less than about 100 microns. Furthermore, the term "extensible" as used herein refers to any fiber that can be elongated by at least about 400% without catastrophic failure, more preferably at least 600% without catastrophic failure, under the action of a biasing force, Even more preferred are fibers that elongate by at least 800% without catastrophic failure.

The following examples further illustrate the products and methods of the present invention.

Example 1

This example demonstrates the melt spinning of the polypropylene resin of the present invention. Specifically, a polypropylene resin (DE, Valtech HH441, Basell Polyolefins Company, Wilmington, Wilmington) with a melt flow rate of 400 was spun using a vertical single-screw extruder mounted on a platform that can be raised and lowered, and equipped with There is a single-hole capillary die and a capillary with a diameter of approximately 86 microns. The molten filament is drawn from the capillary die into air at approximately 25°C using a height-adjustable air-blocking device that uses compressed air at high pressure to create an air flow that surrounds and draws the filament. The output of the extruder was kept relatively constant at about 0.2 g/min/hole, the distance between the die exit and the air gun was kept at about 41 inches (104.2 cm), and the distance between the air gun and the collection screen was kept at about 25 inches (63.5 cm), the extruder and die set temperatures are as follows - Zone 1 = 380°F (193°C), Zone 2 = 400°F (204.4°C), Zone 3 = 420°F (215.5°C), Die joint = 425°F (218.3°C), die = 420°F (215.5°C), and air gun pressure was adjustable for obtaining and collecting fibers less than about 25 microns in diameter. Under these conditions, fiber samples were collected with diameters in the preferred range of 10 to 30 microns. This example demonstrates that standard fiber forming resins are melt spinnable according to the invention.

Example 2

This example demonstrates the high ductility fibers produced according to the invention. Specifically, the fiber samples of Example 1 were tested according to ASTM standard D3822. Tests were performed on an MTS synergie 400 tensile testing machine (MTS Systems Corporation, Eden Prairie, MN) equipped with a 10 Newton load cell and pneumatic grips. Crosshead Speed Tests were performed on single fiber samples with a gauge length of 1 inch (2.54 cm) at a speed of 2 inches (5.08 cm) per minute. The sample was stretched to break and the elongation at break was recorded and averaged for 10 specimens collected at the same air gun pressure. The resulting elongation at break is shown in Figure 1, where the spinning speed can be calculated from the fiber diameter measured using a microscope according to equation (1). This example shows that small diameter (about 10 to 20 micron) fibers can also have high elongation at break (>600%) when fabricated according to the present invention.

Comparative Example 3

This example compares the extensibility of the fibers of Example 2 to those produced using conventionally sized spinnerets. Specifically, the polypropylene resin in Example 1 was melt spun into fibers using a capillary with a diameter of about 570 microns according to the process and conditions outlined in Example 1, and the elongation at break was determined according to the method outlined in Example 2. The obtained elongation at break is shown in Fig. 1, where the fiber diameter measured by microscope can be used to calculate the spinning speed according to equation (1). This example demonstrates that enhanced extensibility can be obtained at comparable fiber diameters or spinning speeds when fibers are spun according to the invention.

The disclosures of all patents, patent applications (and any patents issued thereon, and any corresponding published foreign patent applications) and publications mentioned in this specification are incorporated herein by reference. However, it is not expressly admitted that any document incorporated by reference herein teaches or discloses the present invention.

While particular embodiments of the present invention have been illustrated and described, it would be obvious that various other changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of this invention.

Claims (9)

1. by the fiber of diameter in 5 to 25 micrometer ranges of melt spinning polymer composition production, it makes described quality output in the scope of every hole per minute 0.01 to 2.0 gram, and described draw ratio is less than 400, and described spinnerette diameters is less than 200 microns.

2. by the fiber of diameter in 5 to 25 micrometer ranges of melt spinning polymer composition production, it makes described fibrous fracture percentage elongation greater than 400%, and described draw ratio is less than 400, and described spinnerette diameters is less than 200 microns.

3. the fiber of claim 2, wherein said fibrous fracture percentage elongation is preferably greater than 800% greater than 600%.

4. each fiber in the claim 1 to 3, the diameter of wherein said fiber is in 10 to 20 micrometer ranges.

5. each fiber in the claim 1 to 4, wherein said draw ratio is less than 150, preferably less than 50.

6. each fiber in the claim 1 to 5, wherein said spinnerette diameters is less than 150 microns, preferably less than 100 microns.

7. each fiber in the claim 1 to 6, wherein said polymer composition comprises one or more polymer that is selected from polyolefin and polyester.

8. non-woven web is characterized in that, it comprises in the claim 1 to 7 each fiber.

9. disposable product is characterized in that, it comprises the non-woven web of claim 8.

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