CN111065769A

CN111065769A - Yarns incorporating fluoropolymer staple fibers

Info

Publication number: CN111065769A
Application number: CN201880049984.9A
Authority: CN
Inventors: J·W·多兰; D·J·迈纳
Original assignee: WL Gore and Associates Inc
Current assignee: WL Gore and Associates Inc
Priority date: 2017-06-02
Filing date: 2018-05-31
Publication date: 2020-04-24
Also published as: JP2020530884A; WO2018222872A1; US20200190706A1; EP3631061A1

Abstract

A yarn made from staple fibers comprising a plurality of fluoropolymer staple fibers having an average caliper of at least 15 microns and a plurality of non-fluoropolymer staple fibers, wherein the ratio of the average caliper of fluoropolymer staple fibers to non-fluoropolymer staple fibers in the yarn is 1.2 or greater. Also taught is a yarn made from staple fibers comprising a plurality of fluoropolymer staple fibers having a rectangular cross-section and an average caliper diameter of at most 500 micrometers and a plurality of non-fluoropolymer staple fibers having an average caliper diameter of at most 40 micrometers.

Description

Yarns incorporating fluoropolymer staple fibers

Technical Field

The present disclosure relates generally to the field of yarns incorporating fluoropolymer staple fibers and articles made therefrom.

Background

Fluoropolymers have been used in various forms as friction modifiers in yarns and ropes. For example, U.S. patent No. 6,132,866 to Nelson et al relates to a staple yarn comprising a blend of 35 to 90 weight percent fluoropolymer fibers and 65 to 10 weight percent of one or more types of blended fibers.

Japanese patent application No. Hei 1[1989] -139833 discloses a fiber material having good flexibility, which is prepared by mixing less than 30% of polytetrafluoroethylene fibers or strands with natural and/or synthetic fibers. Fabrics and cloths made from the disclosed fibrous materials have good drape and improved pilling resistance.

Despite the teachings of the prior art, there remains a need for improved yarns incorporating fluoropolymer staple fibers in combination with other staple fibers to achieve performance advantages heretofore not attainable by the prior art.

Disclosure of Invention

The embodiments covered are defined by the claims, not this summary. This summary is a high-level overview of various aspects and introduces a few concepts that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used alone to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification, any or all of the drawings, and the claims.

In a first embodiment, disclosed herein is a yarn comprising: i) a plurality of fluoropolymer staple fibers having an average caliper (also sometimes referred to as a Feret diameter) of at least 15 micrometers (μm), and ii) a plurality of non-fluoropolymer staple fibers, the fluoropolymer staple fibers and the non-fluoropolymer staple fibers, wherein the ratio of the average caliper of the fluoropolymer staple fibers to the non-fluoropolymer staple fibers in the yarn is 1.2 or greater.

In the substitutionIn an exemplary embodiment, the non-fluoropolymer staple fibers may include a plurality of average caliper diameters. In any of the preceding embodiments, the non-fluoropolymer staple fiber comprises one or more synthetic polymers. In any of the preceding embodiments, the non-fluoropolymer staple fibers comprise one or more natural fibers. In any of the preceding embodiments, the non-fluoropolymer staple fibers include synthetic fibers and natural fibers. In any of the preceding embodiments, the fluoropolymer staple fiber has a substantially rectangular cross-section. In any of the preceding embodiments, the plurality of fluoropolymer staple fibers are oriented predominantly in the outer region of the cross-section when the yarn is viewed in cross-section; and the yarn has a yarn perimeter and at least a portion of the fluoropolymer staple fibers extend outwardly beyond the yarn perimeter. In any of the preceding embodiments, the fluoropolymer is expanded polytetrafluoroethylene (ePTFE). In an alternative embodiment, the fluoropolymer is a polymer having a density of 1.9 grams per cubic centimeter (g/cm)³) Or lower ePTFE. In any of the preceding embodiments, the yarn comprises at least one of the following components: antistatic ingredients, cohesive ingredients, waxes, antimicrobial materials, fragrances, mildewcides, insect repellents, coolants, heating agents, analgesics (analgesics), oleophobic materials (oleophobics), oleophilic materials (oleophiliccs), FR materials, organic pigments, inorganic pigments, signature identification marks, or combinations thereof. In any of the preceding embodiments, the yarn further comprises at least one filler. In any of the preceding embodiments, the yarn further comprises an antimicrobial agent. In any of the preceding embodiments, the ePTFE has a substantially rectangular cross-section. In any of the preceding embodiments, the yarn further comprises at least one continuous filament. In any of the preceding embodiments, the continuous filaments comprise elastic filaments. When measuring the diameter of staple fiber in a yarn incorporating one or more continuous filaments, it is understood that the continuous filament component is not included in the staple fiber measurement. In any of the preceding embodiments, the weight percentage of fluoropolymer staple fibers in the yarn is 35% or less based on the total weight of the yarn. In any of the foregoing embodiments, the yarn of the present invention may be combined with other yarnsThe yarns are assembled into the final article.

In an alternative embodiment, the invention is directed to a yarn made from staple fibers comprising a plurality of fluoropolymer staple fibers having a substantially rectangular cross-section and a plurality of non-fluoropolymer staple fibers, wherein the fluoropolymer staple fibers have an average caliper of 15 μm to 500 μm and the non-fluoropolymer staple fibers have an average caliper of 0.1 μm to 40 μm. In any of the preceding embodiments, the non-fluoropolymer staple fibers comprise one or more average caliper diameters. In any of the preceding embodiments, the non-fluoropolymer staple fibers comprise one or more synthetic polymers, natural fibers, and combinations thereof. In any of the preceding embodiments, the plurality of fluoropolymer staple fibers are oriented predominantly in the outer region of the cross-section when the yarn is viewed in cross-section; and the yarn has a yarn perimeter and at least a portion of the fluoropolymer staple fibers extend outwardly beyond the yarn perimeter. In any of the preceding embodiments, the fluoropolymer comprises ePTFE. In any of the preceding embodiments, the fluoropolymer is of a density of 1.9g/cm³Or lower ePTFE. In any of the preceding embodiments, the yarn comprises at least one of the following components: antistatic ingredients, cohesive ingredients, waxes, antimicrobial materials, fragrances, mildewcides, insect repellents, coolants, heating agents, analgesics (analgesics), oleophobic materials (oleophobics), oleophilic materials (oleophiliccs), FR materials, signature identification markings, or combinations thereof. In any of the preceding embodiments, the yarn further comprises at least one filler. In any of the preceding embodiments, the yarn further comprises at least one continuous filament. In any of the preceding embodiments, the continuous filaments comprise elastic filaments. As noted above, when measuring the diameter of staple fiber in a yarn incorporating one or more continuous filaments, it is understood that the continuous filament component is not included in the staple fiber measurement. In any of the preceding embodiments, the weight percent of fluoropolymer in the yarn is 35% or less based on the total weight of the yarn. In any of the foregoing embodiments, the yarn of the present invention may be combined with other yarns.

The yarns of the present invention may be incorporated into a variety of articles, including but not limited to: a textile, which may be woven, knitted, non-woven, fleece, or the like. Articles incorporating the unique yarn may be apparel, footwear, carpeting, architectural structures, banners, umbrellas, and other articles into which the yarn is incorporated.

In other embodiments, a yarn is disclosed, comprising: i) a plurality of expanded ptfe (ePTFE) staple fibers having an average length of 1.25 inches and an average maximum caliper diameter (sometimes also referred to herein as a feret diameter) of at least 15 micrometers (μm), and ii) a plurality of polyester staple fibers, the ePTFE staple fibers and polyester staple fibers forming a yarn, wherein the weight percentage of ePTFE fibers is 10% based on the total weight of the yarn, and wherein the ratio of the average maximum caliper diameter of the ePTFE staple fibers to the polyester staple fibers in the yarn is 1.2 or greater.

These and other unique features of the present disclosure are described herein.

Drawings

FIG. 1 is a graph of yarn hairiness value versus PTFE density.

Figure 2 is a graph of hand (in grams) versus the percentage of ePTFE staple fiber incorporated into a knit fabric comprising the meta-aramid/ePTFE staple fiber yarn of the examples.

Figure 3 is a graph of hand (in grams) versus the percentage of ePTFE staple fibers blended into a knit fabric comprising the wool/ePTFE staple fiber yarn of the examples.

Definition of

"denier" is the weight per unit length of a fiber or filament. The units of denier are dtex, tex and denier. Tex is the mass of the fiber or filament per 1000 meters of length in grams; dtex is the mass of fiber or filament per 10,000 meters of length in grams, or equivalent to 10dtex to 1 tex. Denier is the mass of a fiber or filament per 9000 meters of length in grams, or equivalent to 0.9 dtex-denier.

"denier per fiber" refers to the average denier of staple fibers formed from tow (e.g., fluoropolymer tow). Staple fibers are generally of various deniers, so "denier per fiber" refers to the average denier of a representative sample of staple fibers.

"pulling" refers to the following operations: which fibrillates the monofilament into an array of fiber elements connected at each distal end, forming a diamond-like or parallelogram configuration on the surface of the initial monofilament. "tow" filaments are those that have undergone a drawing operation. The tow filaments may be later cut into staple fibers.

"fiber" refers to a natural or synthetic material having a length substantially greater than its width.

"filament" refers to a continuous fiber, typically in meters in length, and may be tens, hundreds, or even thousands of meters long. To make the filaments into staple fibers, the filaments may be cut or sheared, for example, using a chopping or rotary blade mechanism (available from DM & E Company located in Shell, North Carolina). The desired cut length is determined by the type of splitting process (e.g., long or short splitting process) or threadline process to be used. In some embodiments, when different types of staple fibers are blended together to form a spun yarn, the staple fibers are similar in length, e.g., the average staple lengths (staple lengths) can be ± 10% or less from each other. In other embodiments, the staple fibers may differ in length from each other by more than ± 10% when different types of staple fibers are blended together to form the spun yarn.

"staple fibers" refers to fibers having a finite length, typically in centimeters (cm). Staple fibers are generally elements having the following characteristics: the aspect ratio (length to width) is greater than about 50:1 and the overall length is less than 250 mm. For the purposes of this disclosure, the term staple fiber is sometimes used to refer to natural or synthetic fibers.

"synthetic fibers" refers to rayon fibers.

The term "substantially rectangular configuration" as used herein is intended to mean staple fibers having a rectangular or near-rectangular cross-section, with or without rounded or sharpened edges (or sides), and an aspect ratio (e.g., width versus height) greater than 1. The fluoropolymer staple fibers described herein may have a substantially rectangular cross-section prior to incorporation into the yarn. After incorporation into the yarn, the cross-section of the fluoropolymer staple fiber may be an irregular rectangular cross-section, i.e., still having an aspect ratio greater than 1.

"average caliper diameter" refers to the average of the maximum cross-sectional diameter measurements of the staple fibers. Techniques for determining the average caliper diameter will be discussed herein.

Detailed Description

The present disclosure relates to yarns incorporating fluoropolymer staple fibers and articles derived therefrom. The yarn comprises: i) a plurality of fluoropolymer staple fibers having an average caliper of at least 15 microns, and ii) a plurality of non-fluoropolymer staple fibers, wherein the ratio of the average caliper of the fluoropolymer staple fibers to the non-fluoropolymer staple fibers in the yarn is 1.2 or greater. In other embodiments, the yarn consists of or consists essentially of: a plurality of fluoropolymer staple fibers and a plurality of non-fluoropolymer staple fibers, and the ratio of the average caliper diameter of the fluoropolymer staple fibers to the non-fluoropolymer staple fibers in the yarn is 1.2 or greater. Methods for determining the average caliper diameter will be described herein, and the ratio of the average caliper diameter of the fluoropolymer staple fibers to the non-fluoropolymer staple fibers may range from 1.2 to less than or equal to 20. In another embodiment, a yarn comprises: (i) a plurality of fluoropolymer staple fibers having a rectangular cross-section and (ii) a plurality of non-fluoropolymer staple fibers, wherein the fluoropolymer staple fibers have an average caliper diameter of 15 μm to 500 μm and the non-fluoropolymer staple fibers have an average caliper diameter of 0.1 μm to 40 μm. In another embodiment, the yarn consists of or consists essentially of: (i) a plurality of fluoropolymer staple fibers having a rectangular cross-section and (ii) a plurality of non-fluoropolymer staple fibers, wherein the fluoropolymer staple fibers have an average caliper diameter of 15 μm to 500 μm and the non-fluoropolymer staple fibers have an average caliper diameter of 0.1 μm to 40 μm.

The fluoropolymer staple fibers may be produced from fluoropolymer filaments or fluoropolymer tows. Suitable fluoropolymers may include any suitable fluoropolymer capable of being formed into a filament or tow, for example, homopolymers and copolymers comprising tetrafluoroethylene. Suitable comonomers may include: for example, ethylene, propylene, vinylidene fluoride, vinylidene chloride, acrylates, methacrylates, fluoroacrylates, fluoromethacrylates, or combinations thereof. Any known additives may be added to the fluoropolymer either before or after the staple fiber is formed. In some embodiments, the additive may be added prior to fiber formation, such that the polymer matrix is filled with the additive. Suitable fillers may be: such as organic fillers, inorganic fillers, thermally conductive materials, electrically conductive materials, thermally insulating materials, electrically insulating materials, silver, carbon black, color pigments, color lakes, color dyes, size/dimension enhancing materials, signature identification markers, UV absorbers, light reflecting materials, or combinations thereof. The fluoropolymer may then be formed into a filament or tow having the desired caliper diameter by any known method. The filaments and/or tows may then be cut or otherwise chopped into staple fibers of a desired length.

In some embodiments, the fluoropolymer staple fibers may be Polytetrafluoroethylene (PTFE) staple fibers or expanded polytetrafluoroethylene (ePTFE) staple fibers. In other embodiments, the fluoropolymer staple fibers are ePTFE staple fibers. A suitable ePTFE may have a density of 1.9 grams per cubic centimeter (g/cm)³) Or less, e.g., 0.2 to 1.9g/cm³. The tenacity of the full density (fulldensity) unexpanded PTFE staple fibers is typically less than 1.8 grams per denier (g/d). Except that the toughness of the ePTFE is greater than, and typically greater than, 1.6 g/d. In other embodiments, the toughness of the ePTFE may be greater than 1.7g/d, or greater than 1.8g/d, or greater than 1.9g/d, or greater than 2.0g/d, or even greater than 2.3g/d, which may provide stronger fibers in the yarn, which may result in improved abrasion resistance, tensile strength, and abrasion resistance.

In some embodiments, as disclosed in U.S. Pat. No. 3,953,566 to GollIn the open, Polytetrafluoroethylene (PTFE) and expanded polytetrafluoroethylene (ePTFE) can be produced in tape form. Full density (i.e., non-expanded) PTFE filaments are believed to have a density of 1.95g/cm³Or a greater density. Due to the reduced density of the filaments, e.g., as disclosed in U.S. Pat. No. 7,060,354 to Baillie, due to the density being less than 1.9g/cm³(in some embodiments, less than 1 g/cm)³) The softening property of expanded PTFE, the drawing process becomes more difficult. Filaments with higher breaking strength are needed to withstand the high tensions required during fibrillation. It is an object of the present invention to provide a yarn incorporating ePTFE staple fibers having a density of about 1.9g/cm³Or lower.

To make PTFE and ePTFE dimensionally more suitable for carding processes, a process called fibrillation or drawing is used to reduce the denier of the filaments. Drawing of ePTFE filaments is disclosed in U.S. patent No. 5,765,576 to Dolan, which is incorporated herein by reference in its entirety. The drawing (twing) process may place significant stress on the filaments as they are sheared, especially when a denier per filament of less than 7 denier per filament is desired.

In certain embodiments, the fluoropolymer staple fibers may have a denier per filament (dpf) of less than about 60, or less than 15. In other embodiments, the dpf of the fluoropolymer may be less than 55, or less than 50, or less than 45, or less than 40, or less than 35, or less than 30, or less than 29, or less than 28, or less than 27, or less than 26, or less than 25, or less than 24, or less than 23, or less than 22, or less than 21, or less than 20, or less than 19, or less than 18, or less than 17, or less than 16, or less than 15. The lower limit of the dpf of the fluoropolymer staple fibers is not particularly critical so long as the ratio of the average caliper diameter of the fluoropolymer staple fibers to the non-fluoropolymer staple fibers in the yarn is 1.2 or greater. The ratio of the average caliper diameters (fluoropolymer staple fiber to non-fluoropolymer staple fiber) may be at least 1.2. Depending on the staple in the yarn, once the ratio of the average caliper diameter is too large, e.g., greater than 20, or greater than 30, or greater than 40, the yarn becomes relatively weak. Thus, in some embodiments, the ratio of the average caliper diameters is less than about 30 or less than about 20. In some embodiments, the ratio is between any of the values listed for 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, 8.0, 8.2, 8.4, 8.6, 8.8, 9.0, 9.2, 9.4, 9.6, 10.8, 10.6, 10.8, 5.8, 12.5, 12, 5.5, 14, 16, 14, 16, or 16.

To incorporate fluoropolymer staple fibers into a staple system (also known as a cotton carding process), the staple (staple) may have a length of less than 77 millimeters (mm), alternatively less than 66mm, alternatively less than 58mm, alternatively less than 48mm, alternatively less than 38mm, alternatively less than 29 mm. To incorporate fluoropolymer staple fibers into a long-staple system (also known as a wool carding process), the staple fibers (the staple) may have a length of less than 200 millimeters (mm), or less than 175mm, or less than 150mm, or less than 125mm, or less than 100mm, or less than 75 mm. In some embodiments, the fluoropolymer staple fibers (e.g., ePTFE staple fibers) may be 25.4mm (1 inch) to 31.75mm (1.25 inches) in length. In some embodiments, the fluoropolymer staple fibers may have a substantially rectangular cross-section. Typically, the length of the fluoropolymer staple fiber should be greater than about 10 mm. Fluoropolymer staple fibers having a length of less than 5mm can be difficult to form into yarns.

The yarns of the present disclosure also include non-fluoropolymer staple fibers. The non-fluoropolymer staple fibers may be one or more synthetic staple fibers, one or more natural fibers, or a combination thereof. Suitable non-fluoropolymer staple fibers may include one or more of the following materials: for example, wool, cotton, silk (silk), flax, hemp, hair from various animals, angora, sisal, ramie (ramie), acrylic, polyester, polyamide, aramid, polyurethane, acetate (acetate), rayon, polybenzimidazole, polybenzoxazole, lyocell, modacrylic, polyvinylidene chloride, carbon, glass, cellulose acetate, cellulose ester, elastic fiber, or combinations thereof. Suitable polyester staple fibers may include: for example, polyethylene terephthalate, poly (1, 3-propylene terephthalate), polybutylene terephthalate, or combinations thereof. Natural fibres (e.g. hair or fur from animals, cotton) are typically used without the need to shorten their length, although fibres may be shortened (as required), for example silk fibres are typically long and may be cut to the required staple length. Synthetic staple fibers are typically produced according to known techniques, for example, by extruding one or more filaments, followed by cutting to the desired staple length. In some embodiments, the non-fluoropolymer includes one or more staple fiber diameters. Any of the additives discussed above may be added to the non-fluoropolymer fiber (or filament) to produce the desired properties.

The non-fluoropolymer staple fibers may have various lengths, typically less than 200 millimeters (mm), or less than 175mm, or less than 150mm, or less than 125mm, or less than 100mm, or less than 75 mm. The denier of the synthetic non-fluoropolymer staple fiber may be less than the denier of the fluoropolymer staple fiber. In some embodiments, the synthetic non-fluoropolymer staple fibers may have a denier of greater than or equal to 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7,. 8, 1.9, or 2.0. The titer ranges of natural fibers (e.g. cotton and wool) are: 0.7 to 2.3 denier for upland cotton and 2 to 16 denier for sheep wool. In some embodiments, one or more non-fluoropolymer staple fibers may be used, each staple fiber independently having its own denier, and thus each non-fluoropolymer staple fiber having one or more average caliper diameters. In some embodiments, the non-fluoropolymer staple fibers may include one or more polymers, for example, two individual and different polymeric staple fibers, or bicomponent fibers produced from polyester and polyamide. In other embodiments, the non-fluoropolymer staple fibers may include one or more natural fibers. In other embodiments, the non-fluoropolymer staple fibers are polyester staple fibers, polyamide staple fibers, or a combination thereof. Where a plurality of non-fluoropolymer staple fibers are used, the average caliper of the non-fluoropolymer staple fibers is the average of the caliper weighted based on the amount (in weight percent) of each non-fluoropolymer staple fiber in the mixture of non-fluoropolymer staple fibers.

In other embodiments, the yarn may also include one or more continuous filaments. The filaments are typically used as a core around which fluoropolymer staple fibers and non-fluoropolymer staple fibers are wrapped. Core spun yarn processes are known in the art, and any of these processes can be used to form a core spun yarn having fluoropolymer staple fibers and non-fluoropolymer staple fibers. If present, the filament may be an elastic filament, e.g., an elastic fiber (elastane), a spandex fiber (spandex), or

Or inelastic filaments, for example, polyester filaments or polyamide filaments.

In certain embodiments, the yarn may be produced according to known processes, including, for example, finish-spinning, open-end spinning, or rotor spinning (rotor spinning), as well as air-jet spinning (air-jet spinning) or vortex spinning (air-vortex spinning) processes. The fine spinning process employs carding, drawing, roving (roving) and spinning. The open spinning or rotor spinning process can make the short fiber enter into the spinning directly without needing to make the fiber to be roving. The fibers are fed into a high speed rotating reservoir where they are mixed and entangled together. Vortex spinning is similar to the open process, bypassing the carding machine to convert staple fiber directly into yarn. The fibers are mixed or entangled in a stationary tube (stationary tub) using turbulent air. Before the yarn is formed, and if desired, crimping (crimp) may be performed using a standard crimping operation (e.g., stuffing box or gear nip roll). The yarns of the present disclosure may include fluoropolymer staple fibers in combination with natural staple fibers, synthetic staple fibers, or both natural staple fibers and synthetic staple fibers. In some embodiments, the yarn may comprise from greater than 1 weight percent fluoropolymer staple fiber to 100 weight percent fluoropolymer staple fiber (based on the total weight of the yarn) using conventional carding, drawing, and spinning processes. In other embodiments, the yarn may comprise from 1 wt% fluoropolymer staple fiber to less than 100 wt% fluoropolymer staple fiber. In other embodiments, the yarn may comprise from 2 to 75 wt%, or from 2 to 50 wt%, or from 2 to 40 wt%, or from 3 to 35 wt% fluoropolymer staple fiber, based on the total weight of the yarn. In some embodiments, the yarn includes fluoropolymer staple fibers and the amount of fluoropolymer staple fibers is less than 35 weight percent based on the total weight of the yarn. In some embodiments, the fluoropolymer staple fibers are relatively uniformly distributed in the yarn, for example, when the yarn is viewed in cross-section. In another embodiment, the disclosed yarn has a cross-section perpendicular to the length of the yarn, the cross-section having an inner region, an outer region, and a perimeter. The plurality of fluoropolymer fibers may be oriented primarily in the outer region of the cross-section and at least a portion of the fluoropolymer staple fibers extend outwardly beyond the yarn perimeter. In some embodiments, at least a portion of the fluoropolymer fibers that extend outward beyond the perimeter of the yarn are ends of fluoropolymer staple fibers. The term "inner region" of a yarn refers to the portion of the yarn that extends from the center of the yarn to the midpoint of the radius, assuming that the yarn is approximately circular in cross-section. The "outer region" of the yarn is the region extending from the midpoint of the radius to the perimeter of the yarn.

Finishes (finishes) such as antistatic and cohesive reinforcing materials may be applied to the fluoropolymer staple fibers and/or non-fluoropolymer staple fibers to increase the efficiency of the carding, drawing, and spinning operations of the yarn forming process. In certain embodiments, unlike full density PTFE staple fibers that do not have pores, the fluorine-containing staple fibers (e.g., expanded PTFE) have pores that are capable of retaining a finishing agent. In addition, one or more additives may be added to the yarn to improve yarn properties. For example, in some embodiments, the yarn may contain at least one of the following components: antistatic ingredients, cohesive ingredients, waxes, antimicrobial materials, fragrances, mildewcides, insect repellents, coolants, heating agents, analgesics (analgesics), oleophobic materials (oleophobics), oleophilic materials (oleophiliccs), fire retardant materials, thermal insulating materials, colorants, signature recognition marks, UV absorbers, light reflecting materials, or combinations thereof.

Several advantages of the disclosed yarn have been discovered through the disclosure. It has been surprisingly found that despite the presence of fluoropolymer staple fibers, which are typically hydrophobic materials and thus are expected to be water repellent, the disclosed yarns and articles made from the yarns wet out at similar rates when compared to the same yarns or articles produced from the same yarns without the fluoropolymer staple fibers. More surprisingly, the yarn and articles produced from the yarn also dried faster when compared to the same yarn or articles produced from the same yarn without the fluoropolymer staple fiber. Second, the disclosed yarns and articles produced from the yarns are soft, durable, quick-drying, and have an excellent hand despite the relatively large caliper of the fluoropolymer staple fiber. This is contrary to the trend in the yarn art, particularly for apparel yarns that have produced fibers of lower and lower denier, i.e., lower denier is directly related to lower caliper diameter for a particular fiber. Yarns with low denier fibers produce fabrics that are soft and have excellent hand. By adding relatively large fluoropolymer staple fibers (i.e., a larger average caliper diameter compared to non-fluoropolymer staple fibers), yarns and fabrics with excellent hand are surprisingly produced. The use of expanded PTFE fibers blended with wool shows another surprising result. The use of expanded PTFE fibers minimizes the hairiness value compared to full density ePTFE fibers in wool.

The fibers are characterized as ideal cylinders (all expressed in cm) of length L and radius r, the surface area being shown by:

volume ═ pi Lr²

Wherein, when the fineness is expressed by denier, the unit length is 9x10⁵cm, fineness in dtex, unit length of 1x10⁶cm, and volume in cm³To represent

Surface area 2 pi rL +2 pi r²。

In g/cm³The density (. rho.) is shown as a function of titer in dtex, L and r in cm:

surface area is shown as a function of density (ρ), r and denier:

for a constant length L of 1cm,

thus, for a given denier, and r is constant, as the density decreases, the surface area increases. An interesting and useful result of the above-described derivation of expanded PTFE, as shown in gore, U.S. patent 3,953,566, is that the cross-sectional area of the expanded PTFE element remains substantially constant as the density of the element decreases as the expansion ratio increases. In the above derivation, r therefore remains constant as the ePTFE density changes, resulting in ePTFE fiber surface area as a function of its denier and density. Thus, it can be seen that as expanded PTFE density decreases, the surface area and surface area benefits (e.g., decreased friction between adjacent elements, decreased surface energy, etc.) increase for a given denier.

The yarns of the present disclosure may be used to produce articles, for example, textiles using any known method of producing textiles from yarns. The textile may be produced by known knitting, weaving or non-weaving processes to produce a knitted textile, woven textile non-woven textile or fleece textile. Suitable examples of textile preparation methods may include: for example, warp knitting, weft knitting, circular knitting, flat knitting, seamless knitting, weaving (weaving) with a wide loom, weaving with a narrow loom, doubling (weaving), rapier weaving (rapier weaving), shuttle weaving (shed weaving), air jet weaving, water jet weaving, projectile loom weaving (jacquard weaving), and jacquard weaving. Suitable examples of nonwoven processes include: such as needle punching, hydroentangling, wet-laid (wet-laid) and melt blowing. A textile may be produced using one or more yarns of the present disclosure, or a textile may include a yarn of the present disclosure and one or more other yarns. It is another object of the present invention to provide an expanded PTFE for use in yarn blends that produces woven or knitted textiles with improved drape or hand.

The present disclosure also relates to a method for reducing the drying time of an article, wherein the method comprises producing an article, wherein the article comprises a yarn comprising: i) a plurality of fluoropolymer staple fibers having an average caliper of at least 15 microns, and ii) a plurality of non-fluoropolymer staple fibers, wherein the ratio of the average caliper of the fluoropolymer staple fibers to the non-fluoropolymer staple fibers in the yarn is 1.2 or greater; and reduced drying time when compared to a similar article produced from a yarn consisting of ii) a plurality of non-fluoropolymer staple fibers.

The present disclosure also relates to a method for reducing water absorption of an article, wherein the method comprises producing an article, wherein the article comprises a yarn comprising: i) a plurality of fluoropolymer staple fibers having an average caliper of at least 15 microns, and ii) a plurality of non-fluoropolymer staple fibers, wherein the ratio of the average caliper of the fluoropolymer staple fibers to the non-fluoropolymer staple fibers in the yarn is 1.2 or greater; and reduced drying time when compared to a similar article produced from a yarn consisting of ii) a plurality of non-fluoropolymer staple fibers.

Measuring and testing method

Fineness of fine filament

The titer of a filament is measured by measuring the mass (in grams) of a filament 90 meters in length and multiplying the result by 100. The mass is measured using a mass balance with an accuracy of at least 0.1 grams. The length is measured using a skein winder (skein reel) with a length detection accuracy of at least 5 cm. A typical electric yarn reeling machine (electric skein reel), such as model ILE-1-SKRM, is available from ILE corporation (ILECompany) located at 28222, Charlotte, N.C.. Three measurements were made and averaged.

Denier per fiber

Denier per fiber (dpf) is measured by spreading a 500 millimeter long section of drawn filament over a flat surface with a dark background (e.g., black or navy blue). The filaments were opened evenly as they were spread and laid on top of the dark color measurement plate. A substantially flat metric ruler is laid over the spread tow filaments to cover the entire width of the filaments. Any fibers displayed adjacent to one side of the meter ruler are counted and the total is summed. The sum is divided by the denier of the filament to give the denier per fiber. One test was performed per sample.

Thickness of filament

The thickness of the tapes and monofilaments was measured using a caliper gauge with an accuracy of 0.1 mm. The caliper was equipped with a 15 mm diameter flat disc pad. Five measurements were made per sample and averaged.

Width of filament

Filament width was measured in a conventional manner using an eye ring with a magnification of 10x to a scale of 0.1 mm. Three measurements were made and averaged to determine the width to the nearest 0.05 mm.

Breaking strength of filament

Filament rupture strength is a measure of the maximum load required to rupture (break) a filament. The breaking strength is measured by a tensile tester, such as the Instron machinery company (Instron machinery company) located in canden, Canton, MA. Instron^TMThe machine is equipped with fiber (horn) jaws suitable for holding the filament and strand elements during tensile load measurement. The crosshead speed of the tensile tester was 25.4cm per minute. The gauge length is 25.4 cm. Five measurements were made for each type of fiber, and are reported in newtonsThe average values are recorded.

Tenacity of filament

The filament tenacity is the filament breaking strength normalized for the filament titer (weight per unit length of the filament). The filament toughness was calculated using the following formula:

tenacity (cN/dtex) of filament-breaking tenacity (cN)/fineness of 100 filament (dtex)

Density of filaments

The filament density was calculated using the previously measured filament titer (weight per unit length), filament width and filament thickness using the following formula:

filament density (g/cm)³) Fine filament fineness (dtex)/filament width (mm)/filament thickness (mm)/10,000

Average caliper diameter of fiber (Feret diameter)

The average caliper diameter can generally be described as the average maximum diameter measurement of the staple fibers in the yarn, which are interchangeably referred to as the Ferrett diameter. The average value can be determined by cutting the yarn to reveal the cross-section. The cross-section is then analyzed to find at least three fluoropolymer staple fibers (more than one cross-section may have to be analyzed). The yarn cross-section is then subjected to microscopy, for example, optical or electron microscopy. The maximum cross-sectional distance of each of the three fluoropolymer fibers in the yarn was measured. The average of the three lengths is then determined. The same procedure is then used to determine the average caliper diameter of the non-fluoropolymer fibers. At least three fibers of each type were measured and the average of the at least three fibers was recorded as the average caliper diameter. In some embodiments, the average caliper diameter is a measurement using the procedure given above. Alternatively, the exterior of the yarn may be inspected using an optical microscope and the fluoropolymer staple fibers and non-fluoropolymer staple fibers visually identified. The maximum width of the fiber can be measured for three individual staple fibers of each type of staple fiber in the yarn and an average can be calculated. In other embodiments, the average caliper diameter is a calculated value based on the assumption that the cross-section of the fluoropolymer fiber is circular and according to the formula provided below. In this disclosure, if the value is a calculated value, the value will be listed as "calculated" and the average caliper diameter will be written as "at least" as a value.

Caliper diameter is given in micrometers (10)^-6Meter) and may also be determined based on the assumption of a substantially circular fiber cross-section, using the following equation:

wherein:

the denier is measured in g/9000m,

density in g/cm³The counting is carried out by the following steps of,

the diameter is measured in microns.

Thermal protection (TPP)

Thermal protection (TPP) is related to the time that second degree burns are recorded, and materials with higher TPP values are believed to provide better burn protection. In one embodiment, a method for improving the thermal protection (TPP) of a thermally stable textile and the thermal protection material formed thereby is described.

TPP test method

Multiple test specimens (6 x 6 inches) of the material were prepared for testing. The thermal resistance was measured using a CSI Thermal Protection Performance (TPP) tester according to the NFPA 1971 standard on sections 6-10 of the 2000 version fire protection Structure Protective suit (Protective Assembly for Structural FireLighting).

Individual materials were tested using 1/4 inch spacing. Also, a kit or assembly having multiple material layups is tested in the contact configuration specified by the test method.

Vertical flame test

Samples of textile material were tested according to ASTM D6413 test standard. The sample was exposed to the flame for 12 seconds. The afterflame times of the three samples were averaged. Textiles with an afterflame of greater than 2 seconds are considered flammable; textiles with an afterflame of less than or equal to about 2 seconds are considered flame retardant.

Through a softness tester (Handle-o-Me)ter) hand feeling

AATCC (american association of textile chemists and dyers) evaluation procedure 5 was used to measure the effect of selective compression on the hand of ePTFE laminates by using the bend test. The apparatus used was a softness tester model 211-5-10 manufactured by Siwen Albert Instrument Co, Philadelphia, Pa. Ten samples of the desired material were cut into squares of about 4 inches by about 4 inches. Five cuts in the weft direction. Five are cut in the warp direction. The samples used were then conditioned at 70 + -2 deg.F, 65 + -% relative humidity (hereinafter "RH") for 4 hours prior to testing. A beam (beam) of about 1000 grams was used to push the test specimen through a slit of about 1/4 ". The resistance related to the bending stiffness of the fabric was measured and displayed numerically. The peak lithium was recorded and used for comparison of the samples. The samples were then tested for average hand using a softness tester.

Elmer doffer Tear Test (Elmerdorf Tear Test)

Tear testing was according to ASTM D1424.

Yarn hairiness score

One end of the 500mm yarn sample was fixed to a loop holder, suspended from the loop holder, and a 25g weight was placed on the second distal end. The yarn is allowed to relax freely to a stable resting state. One line is marked with a marker near or in the middle of the yarn and then a second line is placed or marked 25mm above the first line. The number of fibers extending from the yarn over 0.5 mm over the 25mm marked section was counted visually and the yarn was hairiness graded using reference table 1 below. The test was performed on 7 yarns per sample and the average hairiness fraction was carried up to the next integer to obtain the final result.

TABLE 1 hairiness score

Martindale friction

Abrasion resistance was measured using a martindale abrasion tester model 1305, available from James hill corporation (James Heal), harlef, england. The samples were tested according to standard procedures, the abrasive cloth tested being a wool standard. Only the weight of the fixed plate was used as the applied weight. The number of cycles before the hole in the test candidate is generated is counted. Five samples were performed for each test candidate and the results were averaged.

Examples

Example 1

Expanded PTFE fibres were obtained having the following properties: width: 18.4 mm; thickness: 0.089 mm; fineness number: 2224 tex; density: 1.34g/cm³(ii) a Tensile strength: 61.2 kilograms (kg); toughness: 27.5 g/tex. The fibers are passed vertically over a fibrillation roller (or draw roller) having a gill bar parallel to the axis of rotation. The needle bar (pin bar) (available from Burkhardt Company, switzerland) has 15 needles (pins) per cm, each having a length of 1.2 mm. The fibers passing over the fibrillation roller are positioned so that at least 3 comb bars are in contact with the filaments, the relative speed between one comb bar and the speed of the filaments being 2.8 times faster. The resulting denier per fiber (dpf) is from 15 denier to 30 denier. The average caliper diameter is 40-56 microns.

Example 2

Expanded PTFE fibres were obtained having the following properties: width: 10.3 mm; thickness: 0.13 mm; fineness number: 2000 tex; density: 1.55g/cm³(ii) a Tensile strength: 36.58 kg; toughness: 18.3 g/tex.

The fibers are passed vertically over a series of two fibrillation rollers having gill bars parallel to the axis of rotation. The gill bars are available from burkhart, switzerland, the first roll has 15 needles per cm so that at least 3 gill bars are in contact with the filaments, the relative speed between one gill bar and the filament speed being 1.3 times faster. The protruding length of the needle was 2 mm. The second fibrillation roller has 50 needles per cm so that at least 3 needle bars are in contact with the fibers and the relative speed between one needle bar and the speed of the filaments is 2.3 times faster. The protruding length of the needle was 2 mm. The difference in the speed ratio between the nip assembly and the nip assembly roller (nip assembly roller) feeding the filaments to the first fibrillation roller was 5% faster (or had sufficient tension to allow the needles to penetrate the material). The difference in the rate of speed of filament feed to the nip assembly of the second fibrillation roller and the nip assembly roller was 4% faster. The resulting tow had a denier per fiber (dpf) of 7.

Tow fiber uses DM from Sherrer ratio, N.C.&A stuffer box crimper model CL-21 was purchased from E for crimping. The crimp is from 6 to 20 crimps/inch. Tow fiber uses DM from Sherrer ratio, N.C.&A staple cutter (staple cutter) of type series 20, available from E, was cut into staple fibers. The fiber length was 70mm (uncrimped length). The tow filaments are combined so that the bulk titer (bulk titer) of the total yarn bundle entering the crimper and staple cutter is 75,000 to 120,000 denier. The staple was then opened using an air opener and moved through a 254mm diameter, 3m long duct in a turbulent flow flowing at a volume of 300 standard cubic feet per minute. The rate of staple entering the air stream was 500 g/min and the ratio of staple mass to air was about 60g/m³。

Blending of

The australian grade 1 merino wool and ePTFE staple of this example were weighed and hand blended prior to processing by a mechanical tower air mixer. The weight ratio of ePTFE fibers to wool was 10%. No finishing (sizing) was used to treat wool or ePTFE staple fibers. Removing wool debris and lanolin.

Carding machine

Sliver (sliver) is produced from the blended staple fibres using a wool carding machine (Mackie International). The staple fiber material is manually placed into the hopper of the carding machine, where a pick opener (pick opener) is used to transfer the material onto a conveyor belt that feeds the main cylinder (main cylinder) and the work rolls of the carding machine. No automatic leveling is used during carding. The sliver exited the card through a 2.5 inch diameter bell mouth (pipe), and was then wound into a sliver can. The sliver can is manually transported to the floor of the spinning room.

Spinning yarn

Drawing and drawing were carried out using a pin-servo-drawer gilling servo-drawing machine (pin servo-drawer) model M-3730 from Warner & Swasey Company. The drawing sequence was such that six slivers formed one sliver and the ratio of 6: a ratio of 1. The second drawing stage uses the same servo-draw machine to merge the three strips together, but with a ratio set at 3: 1. Then, the ratio of 3: a draft ratio of 1, the sliver was placed by a pin drawing machine (pindrafter) model M-3680 from vorinavir. The total draft of the sliver was 6 x 3 ═ 54. Auto-leveling is used during all the card drawing and drafting (draft) stages. No roving step is used.

Post-draw was used in the range of 1:5 to 2:1 during yarn spinning. The main draft is an apron (apron) type design. The yarn obtained from the main draw had a ratio of 20: 1 final draft. A twist of 7.5 Twists Per Inch (TPI) was placed in the yarn in the S direction. The resulting weight was 15 counts worsted count or 531 denier single yarn. The average caliper diameter of the PTFE fibers was 61.7 microns, and the average caliper diameter of the wool was 18.1 microns.

Example 3

Preparation of about 7dpf per fiber denier and 1.6g/cm density³Coherent ePTFE fibers (i.e., ePTFE fiber tow). Subsequently, the ePTFE fibers were crimped, cut, and blended with australian grade 1 merino at a 20 mass% PTFE to wool ratio to produce a blended single strand yarn having a denier of 531 in the same manner as in example 2. The calculated average caliper of the PTFE fibers is at least 25 and the average caliper of the wool is 18.

Example 4

Preparation of about 7 denier per fiber and 1.6g/cm density³Coherent ePTFE fibers. Subsequently, the ePTFE fibers were crimped, cut, and blended with australian grade 1 merino at a PTFE to wool ratio of 30 mass% to produce a blended single strand yarn having a denier of 531 in the same manner as in example 2. Calculated PTFE fiberThe average caliper of the dimension is at least 25 and the average caliper of the wool is 18.

Comparative example 5

Commercially available PTFE staple fiber having part number JUSF-W-1 from Ling Qiao e.p.e.w. ltd. located in china was blended with australian grade 1 merino wool to form a yarn in the same manner as in example 2. The PTFE fibers had a denier per fiber of about 15dpf and a density of 2.1g/cm³. The PTFE fiber and merino wool were blended at a ratio of 10 mass% PTFE to wool to produce a blended single strand yarn having a denier of 531. The average caliper diameter of the PTFE fibers was 44.3 micrometers, and the average caliper diameter of the wool was 19.1 micrometers.

Comparative example 6

Commercially available PTFE staple fiber having part number JUSF-W-1 from Ling Qiao e.p.e.w. ltd. located in china was blended with australian grade 1 merino wool to form a yarn in the same manner as in example 2. The PTFE fibers had a denier per fiber of about 15 and a density of 2.1g/cm³. The PTFE fiber and merino wool were blended at a ratio of 20 mass% PTFE to wool to produce a blended single strand yarn having a denier of 531. The calculated average caliper of the PTFE fibers is at least 31 and the average caliper of the wool is 18.

Comparative example 7

Commercially available PTFE staple fiber having part number JUSF-W-1 from Ling Qiao e.p.e.w. ltd. located in china was blended with australian grade 1 merino wool to form a yarn in the same manner as in example 2. The PTFE fibers had a denier per fiber of about 15dpf and a density of 2.1g/cm³. The PTFE fiber and merino wool were blended at a ratio of 30 mass% PTFE to wool to produce a blended single strand yarn having a denier of 531. The calculated average caliper of the PTFE fibers is at least 31 and the average caliper of the wool is 18.

Reference comparative example 8

Commercially available australian grade 1 merino wool was produced as worsted yarn in the same manner as in example 2. The 100% wool worsted yarn obtained was a single strand yarn having a denier of about 531.

The number of fibers extending from the yarns of examples 2 to 7 was scored using the hairiness score. Yarns containing ePTFE fibers of the present invention having a density of 1.6g/cc exhibit less fuzz than yarns containing commercially available PTFE fibers. Furthermore, as the PTFE content increases, the hairiness value decreases. Figure 1 shows the hairiness fraction as a function of the PTFE content in the wool yarn and as a function of the PTFE fiber density.

Table 2 shows the increased strength of the expanded PTFE staple fibers compared to the unexpanded PTFE staple fibers. Table 2 shows the density of 1.6g/cm as described in example 1³And an ePTFE staple fiber having a fiber fineness of 15dpf and a density of 2.1g/cm³And a stress-strain diagram of a commercially available PTFE staple fiber having a fiber fineness of 15 dpf.

TABLE 2 percent stress and Strain

Example 9

Preparation of 7 denier per fiber and 1.6g/cm density³Coherent ePTFE fibers. Subsequently, ePTFE fibers were crimped, cut, and blended with meta-aramid at a ratio of 20 mass% PTFE to meta-aramid in the same manner as in example 2 to produce a blended single-strand yarn having a denier of 450. Meta-aramids were obtained from the Coomu Company of Wilmington, Tex (Chemours Company). The meta-aramid had a fiber length of 76mm and had no finish (finish), but was crimped. The average caliper diameter of the PTFE fibers was 117.6 microns and the average caliper diameter of the meta-aramid was 13.3 microns.

Comparative example 10

From Ling Qiao E.P.E.W. Co., Ltd., in China, Ling Qiao E.P.E.W. company, Ltd., was used in the same manner as in example 2Commercially available PTFE staple fiber, part number JUSF-W-1, is blended with meta-aramid to form a yarn. The PTFE fiber had a denier per fiber of about 15dpf and a density of 2.1g/cm³The average caliper diameter was 32 μm. Meta-aramids were obtained from the company costa, wilmington, texas. The meta-aramid had a fiber length of 76mm and had no finish (finish), but was crimped. The PTFE fiber and meta-aramid were blended at a ratio of 20 mass% PTFE to meta-aramid to produce a blended single strand yarn having a denier of 450.

Comparative example 11

A commercially available meta-aramid was obtained from kemu corporation of wilmington, texas and produced as a spun yarn in the same manner as in example 2. The meta-aramid had a fiber length of 76mm and had no finish (finish), but was crimped. The produced spun yarn was a single-strand yarn having a fineness of about 450 denier.

The yarns from examples 9, 10 and 11 were woven into cloth using a 4-shaft rapier loom from CCI corporation, taipei, taiwan, china. The weave design is a plain weave process that produces a fabric having a weight of 75 ends per inch (epi), 70 picks per inch (ppi), and about 7 ounces per yard (oz/yd)²(237 g/m)²). Table 3 contains the results of the vertical flame test according to ASTM D6413. Two runs of each sample were performed and the average of the two runs was calculated. Table 4 contains the hand and results of the Elmendorf tear test (Elmendorf tear test).

Table 3-vertical flame test; plain weave 5 epi x 70 ²ppi,7.0 oz/yd

TABLE 4 hand and Elemandorf tear test results

Example 12

A density of 0.85g/cm was produced in the same manner as in example 1³Coherent ePTFE (tow) filaments. The filaments are then passed vertically over a series of two fibrillation rolls having pin bars parallel to the axis of rotation. The gill bars are available from Burkhardt Company, located in switzerland, the first roll having 30 needles per cm so that at least 5 gill bars are in contact with the filaments, the relative speed between one gill bar and the filament speed being 1.4 times faster. The second fibrillation roller has 50 needles per cm so that at least 3 needle bars are in contact with the filaments and the relative speed between one needle bar and the filament speed is 2.5 times faster. The difference in the rate of speed of filament feed to the first fibrillation roller between the nip assembly and the nip assembly roller was 5% faster. The difference in the rate of speed of filament feed to the nip assembly of the second fibrillation roller and the nip assembly roller was 4% faster. The higher relative rotational speeds of the nip assembly roller exiting the fibrillation roller and the nip assembly roller fed to the fibrillation roller creates stresses in the filaments. The induced tension helps to keep the filaments in contact with the fibrillating roll. The denier per fiber (dpf) obtained was 7.

The tow filaments were crimped using a stuffer box crimper model CL-21 available from DM & E located in sierr, north carolina. The crimp is from 6 to 20 crimps/inch.

Tow fiber uses DM from Sherrer ratio, N.C.&A staple cutter (staple cutter) of type series 20, available from E, was cut into staple fibers. The fiber length was 76mm (uncrimped length). The tow filaments are combined so that the bulk titer (bulk titer) of the total yarn bundle entering the crimper and staple cutter is 75,000 to 100,000 denier. The staple was then opened using an air opener and moved through a 254mm diameter, 3m long duct in a turbulent flow flowing at a volume of 300 standard cubic feet per minute. The rate of the short fibers entering the air stream is 500 g/min, sinceThe ratio of the mass of the staple fibers to the air is about 60g/m³。

Blending of

The meta-aramid and ePTFE staple materials were weighed and blended by hand prior to entering a mechanical staple mixer (mechanical bench blender). The ratio of ePTFE fiber to meta-aramid was 7.5%. A card sizing agent (card sizing agent) available under part number Selbana UN from koka chemical company (pulchra Chemicals) located in munich, germany was used for the ePTFE and meta-aramid staple fibers. One part of selbannaun was used with six parts of distilled water to prepare a sizing agent. The sizing prepared was applied using an amount of about 1% by weight of the fiber. Thus, the combined weight of the ePTFE and meta-aramid batches was 100kg, and 1kg of sizing was applied to the blend prior to carding.

Carding machine

Slivers were produced from the blended staple fibers using a wool carding machine available from Mackie International Company, ltd, located in ireland. The staple fiber material is manually placed into the hopper of the carding machine, where a pick opener (pick opener) is used to transfer the material onto a conveyor belt that feeds the main cylinder (main cylinder) and the work rolls of the carding machine. Automatic leveling is used during carding. The sliver exited the card through a 2.5 inch diameter bell mouth (pipe), and was then wound into a sliver can. The sliver cans are manually transported to the floor of the spinning room where the material is drawn and drawn.

Drawing and drawing were carried out using a pin-servo-drawer gilling servo-drawing machine (pin servo-drawer) model M-3730 from Warner & Swasey Company. The drawing sequence was such that six slivers formed one sliver and the ratio of 6: a ratio of 1. The second drawing stage uses the same servo-draw machine to merge the three strips together, but with a ratio set at 3: 1. Then, the ratio of 3: a draft ratio of 1, the sliver was placed by a pin drawing machine (pindrafter) model M-3680 from vorinavir. The total draft of the sliver was 6 x 3 ═ 54. Auto-leveling is used during all the card drawing and drafting (draft) stages. No roving step is required because the inherent tensile strength of the sliver is sufficient to withstand the spinning operation.

Post-draw was used in the range of 1:3 to 2:1 during yarn spinning. The main draft is an apron (apron) type design. The yarn obtains a ratio of 24 from the main draft: 1 final draft. A twist of 8 Twists Per Inch (TPI) was placed in the yarn in the S direction. A single-strand yarn having a denier of 450 (500dtex) was obtained.

Example 13

A blended spun yarn was prepared in the same manner as in example 12, except that the blending ratio of ePTFE to meta-aramid was 30%.

Comparative example 14

A reference spun yarn was prepared according to the same carding and spinning procedure described in example 12, except that no ePTFE staple was added. The titer of the yarn obtained was 450 deniers (500dtex) and single-stranded.

The worsted yarns produced in examples 12, 13 and 14 were knitted into 10 inch (254mm) diameter knitted fabrics using a 10 inch diameter circular knitting machine available from bingly Engineering Company, Ltd. Eight packages (supply packages) are fed to the knitting machine using compound needles (compound needle) and using simple lock stitches (24 needles).

A two inch (508 mm) wide by 6 inch (152 mm) long test specimen was cut from a circular knit tube structure. The samples were oriented so that the 6 inch (152 mm) long cut length was in the wale (wale) direction of the knit.

The softness tester was used to determine the hand feel of the knitted sample. Fig. 2 is a graph of the hand results of examples 12, 13 and 14, shown as the percentage of hand relative to ePTFE staple fibers of the present invention blended with meta-aramid staple fibers.

Hand was improved by adding a lower density of ePTFE staple fibers to the meta-aramid yarn.

Example 15

Coherent ePTFE (tow) filaments were produced in the same manner as in example 1, except that the ePTFE had a density of 0.85g/cm³. The filaments are then passed vertically over a series of two fibrillation rolls having pin bars parallel to the axis of rotation. The gill bars are available from Burkhardt Company, located in switzerland, the first roll having 30 needles per cm so that at least 5 gill bars are in contact with the filaments, the relative speed between one gill bar and the filament speed being 1.4 times faster. The second fibrillation roller has 50 needles per cm so that at least 3 needle bars are in contact with the filaments and the relative speed between one needle bar and the filament speed is 2.5 times faster. The difference in the rate of speed of filament feed to the first fibrillation roller between the nip assembly and the nip assembly roller was 5% faster. The difference in the rate of speed of filament feed to the nip assembly of the second fibrillation roller and the nip assembly roller was 4% faster. The higher relative rotational speeds of the nip assembly roller exiting the fibrillation roller and the nip assembly roller fed to the fibrillation roller creates stresses in the filaments. The induced tension helps to keep the filaments in contact with the fibrillating roll. The denier per fiber (dpf) obtained was 7.

Tow fiber uses DM from Sherrer ratio, N.C.&A staple cutter (staple cutter) of type series 20, available from E, was cut into staple fibers. The fiber length was 76mm (uncrimped length). The tow filaments are combined so that the bulk titer (bulk titer) of the total yarn bundle entering the crimper and staple cutter is 75,000 to 100,000 denier. The staple was then opened using an air opener and moved through a 254mm diameter, 3m long duct in a turbulent flow flowing at a volume of 300 standard cubic feet per minute. The rate of staple entering the air stream was 500 g/min, so the ratio of staple mass to air was about 60g/m³。

Blending of

Merino wool and ePTFE staple material were weighed and blended by hand prior to entering the staple mechanical mixer. The weight ratio of ePTFE fibers to wool was 10%. A carding sizing agent (card sizing agent) available from cheka chemical company, munich, germany, under part number Selbana UN was used for ePTFE and wool staple fibers. One part of Selbana UN was used with six parts of distilled water to prepare a sizing agent. The sizing prepared was applied using an amount of about 1% by weight of the fiber. Thus, the total weight of the ePTFE and merino wool batches was 100kg, and 1kg of sizing was applied to the blend prior to carding.

Carding machine

Slivers are produced from the blended staple fibers using a wool card or "long staple card" available from meich international, located in ireland. The staple fiber material is manually placed into the hopper of the carding machine where a pick opener (pick opener) is used to transfer the material onto a conveyor belt that feeds the main cylinder (maintylinder) and the work rolls of the carding machine. Automatic leveling is used during carding. The sliver exited the card through a 2.5 inch diameter bell mouth (pipe), and was then wound into a sliver can. The sliver cans are manually transported to the floor of the spinning room where the material is drawn and drawn.

Post-draw was used in the range of 1:3 to 2:1 during yarn spinning. The main draft is an apron (apron) type design. The yarn obtains a ratio of 24 from the main draft: 1 final draft. A twist of 8 Twists Per Inch (TPI) was placed in the yarn in the S direction. A single-strand yarn having a fineness of 550 denier (611dtex) was obtained.

Example 16

A blended worsted yarn was prepared in the same manner as in example 15 except that the blending ratio of ePTFE to merino wool was 30%.

Comparative example 17

A reference spun yarn was prepared according to the same carding and spinning procedure described in example 15, except that no ePTFE staple was added. The titer of the yarn obtained was 550 denier (611dtex) and single strand.

The worsted yarns produced in examples 15, 16 and 17 were knitted into 10 inch (254mm) diameter knit fabrics using a 10 inch diameter circular knitting machine available from bingly Engineering Company, Ltd. Eight packages were fed into the knitting machine using compound needles and using simple lock stitches (24 needles).

A two inch (508 mm) wide by 6 inch (152 mm) long test specimen was cut from a circular knit tube structure. The samples were oriented so that the 6 inch (152 mm) long cut length was in the wale (wale) direction of the knit. The softness tester was used to determine the hand feel of the knitted sample. FIG. 4 is a graph of the hand results of examples 15, 16 and 17. The hand of examples 15 and 16 was improved relative to comparative example 17 by adding a lower density of ePTFE staple fibers to merino wool.

Example 18

A density of 0.85g/cm was produced in the same manner as in example 1³Coherent ePTFE (tow) filaments. The filaments are then passed vertically over a series of two fibrillation rolls having pin bars parallel to the axis of rotation. The gill bars are available from Burkhardt Company, located in switzerland, the first roll having 15 needles per cm so that at least 3 gill bars are in contact with the filaments, the relative speed between one gill bar and the filament speed being 1.3 times faster. The protruding length of the needle was 2 mm. The second fibrillation roller has 50 needles per cm so that at least 3 needle bars are in contact with the filaments and the relative speed between one needle bar and the filament speed is 2.3 times faster. The protruding length of the needle was 2 mm. Feeding filaments to a first fibrillation rollerThe difference in the speed ratio between the nip assembly and the nip assembly rolls was 5% faster. The difference in the rate of speed of filament feed to the nip assembly of the second fibrillation roller and the nip assembly roller was 4% faster. The higher relative rotational speeds of the nip assembly roller exiting the fibrillation roller and the nip assembly roller fed to the fibrillation roller creates stresses in the filaments. The induced tension helps to keep the filaments in contact with the fibrillating roll. The denier per fiber (dpf) obtained was 7.

Tow fiber uses DM from Sherrer ratio, N.C.&A staple cutter (staple cutter) of type series 20, available from E, was cut into staple fibers. The fiber length was 50mm (uncrimped length). The tow filaments are combined so that the bulk titer (bulk titer) of the total yarn bundle entering the crimper and staple cutter is 75,000 to 120,000 denier. The staple was then opened using an air opener and moved through a 254mm diameter, 3m long duct in a turbulent flow flowing at a volume of 300 standard cubic feet per minute. The rate of staple entering the air stream was 500 g/min, so the ratio of staple mass to air was about 60g/m³. A carded sizing available from cheka chemical company, located in munich, germany, under part number Selbana UN was applied to the ePTFE staple fibers. One part of Selbana UN was used with six parts of distilled water to prepare a sizing agent. The sizing prepared was applied using an atomizer spray nozzle in an amount of about 1% by weight of the ePTFE staple fibers.

Example 19

Preparing a three-component worsted yarn consisting of: PBI (polybenzimidazole) of 50mm length and 1.2dpf, obtained from Performance Products Company, Inc, located in charlotte, north carolina, and para-oriented polyamide staple fibers of 50mm length and 1.3dpf, obtained from dupont Company, e.i. dupont Company, wilmington, tera, usa, and ePTFE staple fibers prepared in the same manner as described in example 18. The staple fibers were weighed and blended by hand and subsequently processed through a mechanical mixer. The ePTFE fiber content by weight was 20%, the PBI content by weight was 40%, and the para-aramid content by weight was 40%.

Sliver is produced from blended staple fibers using a cotton carding machine (or short staple carding machine) model TC15, located in telitz corporation, GmbH, germany, the card wire is used as a flat (flat) rather than a work roll.

Drawing and drawing were accomplished using an auto leveling pin draw frame (auto leveler pin draw frame) similar to model TD8 from telitz corporation, germany. The drawing sequence was such that seven slivers were formed into one sliver and drawn at a ratio of 7: 1. The second drawing stage uses the same servo-draw machine to merge the three strips together, but with a ratio set at 3: 1. Then, the ratio of 3: a draft ratio of 1, the sliver is set by a pin draft machine (pin draft). The total draft of the sliver was 7 × 3 × 3 ═ 63. Auto-leveling is used during all draw stages.

The post draft main draft used during yarn spinning was an apron (apron) type design in the range of 1:3 to 2: 1. The yarn obtained from the main draw ratio was 15: 1 final draft. A twist of 26 Twists Per Inch (TPI) was placed in the yarn in the S direction. The resulting single yarn weighed 12 cotton count (cotton count) or 446 denier (496 dtex).

Comparative example 20

A bicomponent worsted yarn was prepared in the same manner as in example 24, the worsted yarn consisting of: PBI (polybenzimidazole) of 50mm length and 1.2dpf, obtained from performance products ltd, charlotte, north carolina, and para-oriented ePTFE polyamide staple fiber of 50mm length and 1.3dpf, obtained from dupont, wilmington, tera, usa, but without staple fiber. The PBI content was 40% by weight and the para-aramid content was 60% by weight.

The resulting single yarn was twisted with 26TPI and weighed 12 cotton count or 446 denier (496 dtex).

Example 21

The yarn formed in example 19 was woven on a 4-harness rapier loom available from chenille limited, donnier company, GmbH, located in the forest lane of germany, to form a plain weave of 43epi × 43ppi and a weight of 5.56 osy. The abrasion of the woven cloth was tested using a standard Martindal (Martindal) test.

Comparative example 22

The yarn formed in comparative example 20 was woven on a 4-harness rapier loom obtained from chenille gmbh located in the forest lane of germany to form a plain weave of 43epi × 43ppi and a weight of 5.57 osy. The abrasion of the woven cloth was tested using a standard Martindal (Martindal) test.

Table 5 summarizes the results of the martindale test for example 21 and comparative example 22. The abrasion resistance of the fabric containing the staple fibers of the invention was improved by more than 65% over the abrasion resistance of the fabric composed of the comparative staple fibers.

TABLE 5 Martindale abrasion results for examples 21 and 22

Example 23

Expanded PTFE fibers are provided having the following properties:

width: 50 mm; thickness: 0.055 mm; fineness number: 22,222 tex; density: 1.6g/cm³. The filaments are passed vertically over a fibrillation roller (or draw roller) having a gill bar parallel to the axis of rotation. Needles available from burkhart, switzerlandThe comb bar (pin bar) has 30 needles (pins) per cm, each needle having a length of 1.2 mm and protruding from a position perpendicular to the surface of the roll by 30 degrees. The needle is oriented such that the needle points away from the direction of approach to the filament, such that the needle sweeps into the filament rather than picking up at the filament. The filaments passing over the fibrillation roller are positioned so that at least 7 comb bars are in contact with the filaments, the relative speed between one comb bar and the speed of the filaments being 2.6 times faster. The resulting product was a system denier of about 2,222tex of a tow ePTFE filament consisting of an array of discontinuous fibers having a denier per fiber (dpf) of about 15.

The tow ePTFE filaments were crimped and then passed over a hot plate set at 170 ℃ for a residence time of about 2 seconds and crimped by passing the filaments through a dual gear assembly comprising two steel gears 100mm in diameter and 50mm wide having serrations parallel to the gear shaft on the outer surface, thereby creating crimps in the filaments made up of serrations or indentations spaced about 1/8 inches (3.2 mm) apart.

The crimped, spun ePTFE filaments were cut into staple fibers using a staple cutter (staple cutter) similar to model series 20 available from DM & E located in scherr, north carolina. The tow filaments are combined so that the bulk titer (bulk titer) of the total yarn bundle entering the crimper and staple cutter is 75,000 to 120,000 denier. The cut fiber length was 25.4mm long and the crimp level was 8 crimps per inch (3.2 crimps/cm). The average caliper diameter of the ePTFE fibers was 36 microns. A carded sizing available from cheka chemical company, munich, germany, under part number selbanaaun was applied to the ePTFE staple fibers. One part of Selbana UN was used with six parts of distilled water to prepare a sizing agent. The sizing agent prepared was applied using an amount of about 2% by weight of ePTFE staple fiber.

The sized ePTFE staple fibers, having a length of 38mm and a denier of 1.2 (1.33dtex), were hand blended with polyester staple fibers having a brand name SFX available from three-lane Group Ltd, Sanfangxiang Group co. The blend ratio was 10% ePTFE staple and 90% polyester staple. The hand blended staple fibers were further blended using a mechanical mixer available from Hollingsworth Company.

A short staple carding machine model DK903 available from telitchler corporation received the blended short fibers from a mechanical mixer from hollingwals corporation. Automatic leveling is used during carding, where the grain weight (grain weight) target of the generated sliver is 75 grains/code. The sliver leaving the carding machine and being wound into a sliver can be used with a can filling station (can filling station) of the company telnozzle, model KH 750/800. The strip was drawn on a drawing machine of model number RSB 851 available from rita corporation (Rieter Company). Drawing is to connect 6 strips into one and draw at a ratio of 6.9:1 to produce a strip weight of 65 weaves/yard. The strips were drawn a second time to make 6 strips into one strip and drawn at a ratio of 7.1:1 to produce a weight of 55 weaves/yard.

The 55 rib/yard sliver was twisted and drafted at a ratio of 10.9:1 to produce a roving having a weight of 1.65Ne roving count. And feeding the roving into a spinning chamber for spinning. A SIRO spinning process was performed in which two rovings were combined prior to a drafting zone and a twisting zone to produce a yarn with a weight of 30/1. The roving (HR) was 0.825Ne (english count or cotton count) and the total draft during spinning was 36.4: 1. The twist multiplier (t.m.) was 3.5. The yarn is waxed. It was observed that the resulting yarn was softer than a similarly treated control yarn without ePTFE staple content. The presence of multiple ends of the PTFE staple fibers occurs at the surface of the yarn. The cross section of the yarn showed an average caliper diameter of the ePTFE staple fibers of 67 microns and the polyester staple fibers of 13 microns.

Example 24

The spun ePTFE filaments from example 23 were crimped and cut into ePTFE staple fibers. The tow was passed over a hot plate set at 170 ℃ for a dwell time of about 2 seconds and the filament crimped by passing the filament through a double gear assembly comprising two steel gears 100mm in diameter and 50mm wide having serrations parallel to the gear axis on the outer surface to produce a crimp in the filament consisting of serrations or indentations spaced about 1/8 inches (3.2 mm).

The crimped, spun ePTFE filaments were cut into staple fibers using a staple cutter (staple cutter) similar to model series 20 available from DM & E located in scherr, north carolina. The tow filaments are combined so that the bulk titer (bulk titer) of the total yarn bundle entering the crimper and staple cutter is 75,000 to 120,000 denier. The cut fiber length was 32mm long and the crimp level was 8 crimps per inch (3.2 crimps per cm) and the average caliper diameter of the fiber was 36 micrometers.

A carded sizing available from cheka chemical company, located in munich, germany, under part number Selbana UN was applied to the ePTFE staple fibers. One part of Selbana UN was used with six parts of distilled water to prepare a sizing agent. The sizing agent prepared was applied using an amount of about 2% by weight of ePTFE staple fiber.

The sized ePTFE staple fibers, 38mm in length, 1.2 denier (1.33dtex) in average caliper of 12, were hand blended with polyester staple fibers, available under the brand name SFX from Sanfangxiang Group co, Ltd, located in Jiangsu, China. The blend ratio was 10% ePTFE staple and 90% polyester staple. The hand blended staple fibers were further blended using a mechanical mixer available from Hollingsworth Company.

The 55 rib/yard sliver was twisted and drafted at a ratio of 10.9:1 to produce a roving having a weight of 1.65Ne roving count. And feeding the roving into a spinning chamber for spinning. A SIRO spinning process was performed in which two rovings were combined prior to a drafting zone and a twisting zone to produce a yarn with a weight of 30/1. The roving (HR) was 0.825Ne and the total draft during spinning was 36.4: 1. The twist multiplier (t.m.) was 3.5. The yarn is waxed.

The resulting yarn was observed to be softer than a control 100% polyester yarn similarly treated but without the ePTFE staple content. The yarn appeared to have less fuzz than the control yarn, which consisted of 100% polyester.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of the present invention that certain changes and modifications may be practiced within the scope of the appended claims. In addition, each reference provided herein is incorporated by reference in its entirety as if each reference were individually incorporated by reference.

Claims

1. A yarn, comprising:

i) a plurality of fluoropolymer staple fibers having an average caliper diameter of at least 15 micrometers; and

ii) a plurality of non-fluoropolymer staple fibers, said staple fibers i) and ii),

wherein the ratio of the average caliper diameter of the fluoropolymer staple fiber to the non-fluoropolymer staple fiber is 1.2 or greater.

2. A yarn according to claim 1, wherein said non-fluoropolymer staple fibers comprise one or more staple diameters.

3. A yarn according to claim 1 or 2, wherein the non-fluoropolymer staple fibers comprise one or more synthetic staple fibers, one or more natural fibers, or a combination thereof.

4. A yarn according to any one of claims 1 to 3, wherein said fluoropolymer staple fibers have a substantially rectangular cross-section.

5. A yarn according to any one of claims 1 to 4, wherein said fluoropolymer comprises ePTFE.

6. A yarn as in any one of claims 1 to 5, wherein the fluoropolymer comprises a density of 1.9 grams per cubic centimeter (g/cm)³) Or lower ePTFE.

7. The yarn of any one of claims 1 to 6, further wherein the yarn comprises at least one of the following: an antistatic ingredient, a cohesive ingredient, a wax, an antimicrobial material, a fragrance, a mildewcide, an insect repellant, a coolant, a heating agent, an analgesic, an oleophobic material, a lipophilic material, an FR material, an organic pigment, an inorganic pigment, a signature identification indicia, or a combination thereof.

8. A yarn according to any one of claims 1 to 7, wherein the fluoropolymer staple further comprises at least one organic filler, inorganic filler, thermally conductive material, electrically conductive material, thermally insulating material, electrically insulating material, silver, carbon black, color pigment, color lake, color dye, size/dimension enhancing material, signature recognition mark, UV absorber, light reflective material or combinations thereof.

9. A yarn according to any one of claims 1 to 8, wherein the yarn further comprises one or more continuous filaments.

10. A yarn according to claim 9, wherein said continuous filament comprises an elastic filament.

11. A yarn according to any one of claims 1 to 10, wherein the weight percentage of fluoropolymer staple fibers is 35% by weight or less, based on the total weight of the yarn.

12. The yarn of any one of claims 1 to 11, further in combination with other yarns.

13. A yarn according to any one of claims 1 to 12, in the form of a woven, non-woven, fleece or knitted article.

14. A yarn, comprising:

ii) a plurality of fluoropolymer staple fibers having a rectangular cross-section; and

ii) a plurality of non-fluoropolymer staple fibers,

wherein the fluoropolymer staple fibers have an average caliper diameter of 15 to 500 micrometers and the non-fluoropolymer staple fibers have an average caliper diameter of 0.1 to 40 micrometers.

15. A yarn according to claim 14, wherein said non-fluoropolymer staple fibers comprise one or more staple diameters.

16. A yarn according to any one of claims 14 to 15, wherein the non-fluoropolymer staple fibers comprise one or more synthetic staple fibers, one or more natural fibers, or a combination thereof.

17. A yarn according to any one of claims 14 to 16, wherein said fluoropolymer staple fibers have a substantially rectangular cross-section.

18. A yarn according to any one of claims 14 to 17, wherein said fluoropolymer comprises ePTFE.

19. The article of any of claims 14 to 18, wherein the fluoropolymer is of a density of 1.9g/cm³Or moreLow ePTFE.

20. A yarn according to any one of claims 14 to 19, wherein the yarn comprises at least one of the following components: an antistatic ingredient, a cohesive ingredient, a wax, an antimicrobial material, a fragrance, a mildewcide, an insect repellant, a coolant, a heating agent, an analgesic, an oleophobic material, a lipophilic material, an FR material, an organic pigment, an inorganic pigment, a signature identification indicia, or a combination thereof.

21. A yarn according to any one of claims 14 to 20, wherein the yarn further comprises at least one organic filler, inorganic filler, thermally conductive material, electrically conductive material, thermally insulating material, electrically insulating material, silver, carbon black, color pigment, color lake, color dye, size/dimension enhancing material, signature recognition mark, UV absorber, light reflective material or combinations thereof.

22. A yarn according to any one of claims 14 to 21, wherein the yarn further comprises one or more continuous filaments.

23. A yarn according to claim 22, wherein said continuous filament comprises an elastic filament.

24. A yarn according to any one of claims 14 to 23, wherein the weight percentage of fluoropolymer in the yarn is 35% by weight or less, based on the total weight of the yarn.

25. A yarn according to any one of claims 14 to 24, wherein the yarn is combined with other yarns.

26. A yarn as claimed in any one of claims 14 to 25 in the form of a woven, non-woven, knitted or fleece article.

27. An article comprising a yarn, comprising:

i) a plurality of expanded PTFE staple fibers having a length of 1 inch to 1.25 inches and an average caliper of at least 30 micrometers; and

ii) a plurality of polyester staple fibers, said staple fibers i) and ii) being formed into a yarn,

wherein the expanded PTFE staple fibers comprise 10 weight percent of the total yarn, and the ratio of the average caliper diameter of the ePTFE staple fibers to the polyester staple fibers is 1.2 or greater.

28. An article comprising a yarn, comprising:

ii) a plurality of expanded PTFE (ePTFE) staple fibers having a rectangular cross-section; and

(ii) a plurality of polyester staple fibers formed into a yarn, the ePTFE staple fibers being present in an amount of 10% by weight of the total yarn,

wherein the expanded PTFE staple fibers have an average caliper of 30 to 500 micrometers, and the polyester staple fibers have an average caliper of 10 to 40 micrometers.