TW202210679A - A method to make bicomponent fibers and articles comprising the same - Google Patents

Abstract

The disclosure generally relates to bicomponent fibers, and more particularly, methods to make bicomponent fibers and articles comprising them. The bicomponent fibers may comprise polyesters and are useful in articles such as carpets, fabrics, and etc.

Description

Method of making bicomponent fibers and articles containing the same

The present disclosure relates generally to bicomponent fibers, and more particularly to methods for making bicomponent fibers and articles comprising the bicomponent fibers.

Bicomponent fibers produced by spinning two polyesters side-by-side are widely used in the textile industry, primarily to impart elasticity in final garments or articles. The degree of stretching can be manipulated by the relative shrinkage of the two polyesters, which can depend in part on the intrinsic viscosity (I.V.) of the two polymers. In the manufacture of bicomponent fibers, ideally, the polyester starting material to be used has the required I.V. and is readily available and inexpensive. When this is not the case, often during the fiber manufacturing process, the physical properties of the bicomponent fiber, or both, must be compromised to achieve the desired performance characteristics of the bicomponent fiber.

In a first embodiment, disclosed herein is a method for making bicomponent fibers, the method comprising: a) extruding a first and second component; b) combining the melt stream in a spinneret suitable for making bicomponent fibers; c) quenching the bicomponent fibers produced in step (b) in air; d) drawing and heat setting the quenched bicomponent fibers; and e) winding by any suitable means The bicomponent fibers in step (d); wherein the first extruded component has a lesser moisture content than the second extruded component.

All patents, patent applications, and publications cited are incorporated herein by reference in their entirety.

Range and Variations

Where present, all ranges are inclusive and combinable. For example, when a range of "1 to 5" is recited, the recited range should be construed to include "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", " 1 to 3 and 5", etc.

As used herein in connection with numerical values, the term "about" refers to a range of +/- 0.5 of the index value, unless the term is specifically defined otherwise in the context. For example, the phrase "a pH of about 6" refers to a pH of 5.5 to 6.5, unless the pH is specifically defined otherwise.

Every maximum numerical limitation given throughout this specification is intended to include every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.

definition

As used herein, the terms "embodiment" or "disclosure" are not meant to be limiting, but generally apply to any implementation defined in the claims or described herein. These terms are used interchangeably herein. In this disclosure, a number of terms and abbreviations are used. Unless specifically stated otherwise, the following definitions apply.

The articles "a/an" and "the" preceding an element or component are intended to be non-limiting in relation to the number of instances (ie, occurrences) of that element or component. Thus, "a/an" and "the" should be understood to include one or at least one, and the singular word form of an element or component also includes the plural unless the number clearly implies means singular.

The term "comprising" means the presence of specified features, integers, steps or components as referred to in the scope of the claim, but does not exclude one or more other features, integers, steps, components or their Group presence or addition. The term "comprising" is intended to include embodiments encompassed by the terms "consisting essentially of" and "consisting of". Similarly, the term "consisting essentially of" is intended to include embodiments encompassed by the term "consisting of."

As used herein, the term "bicomponent fiber" refers to a fiber comprising two different polymer components, which may be composed of different polymer types, the same polymer type but with different intrinsic viscosities, or a blend of two or more polymers. Bicomponent fibers may also be referred to as conjugate fibers, and these terms may be used interchangeably.

The term "BCF" refers to bulk or bulked continuous bicomponent filaments. It is basically a long continuous bundle of fibers used to make carpets. The terms "puffing" and "puffing" are used interchangeably herein.

As used herein, the term "carpet" refers to a floor covering consisting of pile yarns or fibers and a backing system. They can be tufted or woven. As used herein, The term "rug" includes whole-house rugs, tile rugs, rugs, and mats for vehicle and building entrances, such as those designed to trap dirt underfoot.

The term "face" refers to the side of the carpet containing the tufted or woven yarns.

As used herein, the term "face fibers" refers to the fibrous inclusions of a carpet, including those visible to an observer. The face fibers are primarily made of yarns, and the yarns can be styled in cuts, loops, cuts and loops, or any number of styles known to those skilled in the art.

The term "copolymer" refers to a polymer consisting of a combination of more than one monomer. Copolymers can form the basis of some man-made fibers.

The term "crimp" refers to the waviness of a fiber, expressed as number of crimps per unit length. "Crimping" is the process of imparting crimp to filament yarn.

The term "crimp contraction" is a measure of fiber crimp and refers to the contraction in length of a yarn from a fully extended state (ie, in which the filaments are substantially straight). This is due to the formation of crimps in the individual filaments under certain crimp development conditions. It is expressed as a percentage of stretched length. Crimping shrinkage can be measured before and/or after fibers are processed (eg, by heating) to partially or fully develop crimp; typically, crimp shrinkage after heating is more interesting and informative because it includes The curl developed by heating. Unless otherwise stated, crimp shrinkage values disclosed herein are post-heat crimp shrinkage values (Cca).

The term "denier" is a measure of weight per unit length of any linear material.

The term "fiber" refers to a unit of matter, either natural or synthetic, that forms the basic element of fabric and other textile structures. It is characterized by having a length at least 1000 times its diameter or width. Typically, textile fiber systems can be spun into yarns or made into units of fabric by various methods including weaving, knitting, braiding, carpeting, and twisting. Fibers are characterized by their denier (grams by weight per 9000 meters of fiber) and the number of filaments contained in the fiber.

"Filament" refers to a thin thread or continuous bundle of fibers. There are two types of filaments: mono-filament and multi-filament. A filament is characterized by its denier per filament ("dpf").

The term "homofilament" means that the filament is made of one type of polymer.

"Staple" refers to natural fibers or lengths cut from filaments.

The term "intrinsic viscosity" (IV) refers to the ratio of the specific viscosity of a solution of known concentration to the solute concentration extrapolated to zero concentration.

The term "tufting" refers to the process of manufacturing textiles, such as carpets, on specialized multi-needle machines. A "tuft" is a tuft of soft yarn that is drawn through the fabric and protrudes from the surface in the form of severed yarns or loops. Severed or unsevered loops form the face of a tufted or woven carpet.

The term "yarn" refers to a collection of individual filaments, either individually or plied together with another collection of filaments. The terms "fiber" and "yarn" are used interchangeably herein.

The term "quenching" refers to rapid cooling in water, oil or air to obtain certain physical or material properties.

The term "poly(ethylene terephthalate)" or PET means a polymer derived substantially exclusively from ethylene glycol and terephthalic acid (or equivalents such as dimethyl terephthalate), and Also known as poly(ethylene terephthalate) homopolymer. As used herein, the term "poly(ethylene terephthalate) copolymer" or "co-PET" refers to a composition comprising repeating units derived from ethylene glycol and terephthalic acid (or equivalent) and also containing A polymer derived from at least one additional unit of an additional monomer such as isophthalic acid (IPA) or cyclohexanedimethanol (CHDM). Poly(ethylene terephthalate) The ester) copolymer may contain from about 1 mol % to about 30 mol % of additional monomer, eg, from about 1 mol % to about 15 mol % of additional monomer.

The term "poly(butylene terephthalate)" or PBT means a polymer derived substantially exclusively from 1,4-butanediol and terephthalic acid, and is also known as poly(butylene terephthalate) alcohol ester) homopolymer. As used herein, the term "poly(butylene terephthalate) copolymer" refers to a copolymer comprising repeating units derived from 1,4-butanediol and terephthalic acid and also containing at least one derived from other monomers ( For example, polymers of other units of the comonomers of the PTT copolymers as disclosed herein.

The term "poly(trimethylene terephthalate)" or PTT refers to polyesters made by polymerizing 1,3-propylene glycol and terephthalic acid. It is characterized by high elastic recovery and resilience. PTT is known to provide stain resistance, static resistance and improved dyeability. The term "poly(trimethylene terephthalate) homopolymer" means a polymer that is essentially only 1,3-propanediol and terephthalic acid (or equivalent). The term "poly(trimethylene terephthalate)" also includes PTT copolymers, which are meant to contain repeating units derived from 1,3-propanediol and terephthalic acid (or equivalent) and also contain repeat units derived from A polymer of at least one additional unit of additional monomer.

Examples of PTT copolymers include copolyesters made using three or more reactants each having two ester-forming groups. For example, copoly(trimethylene terephthalate) may be used wherein the comonomer used to make the copolyester is selected from linear, cyclic and branched aliphatic dicarboxylic acids having 4 to 12 carbon atoms (eg , succinic acid, glutaric acid, adipic acid, dodecanedioic acid and 1,4-cyclo-hexanedicarboxylic acid); aromatic dicarboxylic acids other than terephthalic acid and having 8-12 carbon atoms Acids (for example, isophthalic acid and 2,6-naphthalenedicarboxylic acid); linear, cyclic and branched aliphatic diols (except 1,3-propanediol, for example, ethylene glycol) having 2-8 carbon atoms Diol, 1,2-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1 , 3-propanediol and 1,4-cyclohexanediol); and aliphatic and aromatic ether diols having 4-10 carbon atoms (eg, hydroquinone bis(2-hydroxyethyl) The group consisting of ethers or poly(vinyl ether) glycols having a molecular weight of less than about 460, including dipethylene ether glycol). Comonomers are typically present in the copolyesters on an order of magnitude ranging from about 0.5 mol% to about 15 mol%, and may be present in amounts up to about 30 mol%.

The term "Triexta" refers to the generic name for the subclass of polyester, PTT. The terms Triexta and PTT are used interchangeably herein.

The intrinsic viscosity of the poly(trimethylene terephthalate) is typically about 0.5 deciliters per gram (dl/g) or more, and usually about 2 dl/g or less. Poly(trimethylene terephthalate) preferably has about 0.7 dl/g or higher, more preferably 0.8 dl/g or higher, even more preferably 0.9 dl/g or higher Intrinsic viscosity, and typically the intrinsic viscosity is about 1.5 dl/g or less, preferably 1.4 dl/g or less, and currently available commercial products have intrinsic viscosities of 1.2 dl/g or less. Poly(trimethylene terephthalate) is commercially available under the trademark "Sorona®" from E.I. du Pont de Nemours and Company, Wilmington, DE.

Carpets made from poly(trimethylene terephthalate) monocomponent fibers and their manufacture, and the manufacture of such fibers and fibers are described in US Pat. Nos. 5,645,782 Howell et al, 6,109,015 Roark et al, and 6,113,825 Chuah; US Pat. Nos. 6,740,276, 6,576,340 and 6,723,799; WO 99/19557 Scott et al; H. Modlich, "Experience with Polyesters Fibers in Tufted Articles of Heat-Set Yarns", Chemiefasern/Textilind. [Chemical Fibers/Textile Industry] 41/93, 786-94 (1991); and H. Chuah, "Corterra Poly(trimethylene terephthalate)-New Polymeric Fiber for Carpets [Corterra Poly(trimethylene terephthalate)- Novel Polymer Fibers for Carpets]", The Textile Institute, Tifcon '96 (1996), all references incorporated herein by reference. Staple fibers are primarily For the preparation of household carpets. BCF yarns are used to make all types of carpets and are generally preferred for carpets.

Typically, PTT-containing bicomponent fibers are used to make fabrics and garments with durable stretch properties. In contrast, such stretch properties are not required in the manufacture of carpets. In contrast, fibers used to make carpets are typically mechanically bulked to provide a high degree of bulk; such fibers are typically referred to as "BCF" fibers.

Overview

Applicants have advantageously discovered a method for making bicomponent fibers by controlling the in-line I.V. of the starting polymer, which method allows: the use of inexpensive polymers as needed in the fiber manufacturing process; and optimizing bulk fiber properties while simultaneously Not limited to polymer I.V..

Applicants have also advantageously discovered a method for making bicomponent fibers by controlling the I.V. of the off-line starting polymer.

Disclosed herein is a method for making bicomponent fibers.

The method comprises: a) extruding the first and second components on a spinning machine capable of producing two or more independent melt streams; b) combining the first and second components in a spinneret suitable for making bicomponent fibers melt flow; c) quenching the bicomponent fibers produced in step (b) in air; d) drawing and heat setting the quenched bicomponent fibers; and e) by any suitable means of winding the bicomponent fibers in step (d); wherein the first extruded component has a lesser moisture content than the second extruded component.

The first and second components of the methods disclosed herein may independently comprise polyester and nylon, and combinations thereof.

The first and second components of the bicomponent fibers may be present in a weight percent ratio of 20:80 to 80:20. The weight percentage ratio can be selected from 20:80, 25:75, 30: 70, 35:65, 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, and 80:20.

The first and second components may independently comprise polyester and nylon homopolymers, copolymers, blends, and combinations thereof.

In one embodiment, the first and second components may independently comprise a component selected from the group consisting of poly(trimethylene terephthalate), poly(ethylene terephthalate), poly(butylene terephthalate) alcohol esters), and polyesters of the group consisting of combinations thereof.

In one embodiment, the polyesters in the bicomponent fibers may be copolyesters, and such copolyesters are included in poly(ethylene terephthalate) and poly(trimethylene terephthalate). In that sense, the premise is that such variants do not adversely affect the amount of crimp of the entangled yarn or the processing properties of the fibers. For example, copoly(ethylene terephthalate) may be used wherein the comonomer used to make the copolyester is selected from linear, cyclic and branched chain aliphatic dicarboxylic acids having 4 to 12 carbon atoms (eg succinic acid, glutaric acid, adipic acid, dodecanedioic acid and 1,4-cyclohexanedicarboxylic acid); aromatic dicarboxylic acids other than terephthalic acid and having 8 to 12 carbon atoms Acids (eg, isophthalic acid and 2,6-naphthalenedicarboxylic acid); linear, cyclic and branched aliphatic diols having 3 to 8 carbon atoms (eg 1,3-propanediol, 1,2 -Propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol and 1 , 4-cyclohexanediol); and aliphatic and araliphatic ether diols having 4 to 10 carbon atoms (eg, hydroquinone bis(2-hydroxyethyl) ether or poly( Ethylene ether) diol, including the group consisting of dipethylene ether diol): . The comonomer may be present in the copolyester on the order of about 0.5 to about 15 mole percent. Isophthalic acid, glutaric acid, adipic acid, 1,3-propanediol and 1,4-butanediol are typically used because they are readily commercially available and inexpensive. The copolyester may also contain small amounts of other comonomers. Such other comonomers include, but are not limited to, sodium 5-sulfoisophthalate on the order of about 0.2 to about 5 mole percent. Very small amounts of trifunctional comonomers (eg trimellitic acid) can also be incorporated to control viscosity.

In one embodiment, the first and second components may independently comprise poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co - PET), poly(trimethylene terephthalate) (PTT) polymers or blends of PTT with PET homopolymers or PET copolymers (co-PET).

In one embodiment of the bicomponent fibers, the first component may comprise PTT and the second component may comprise PET, wherein the bicomponent fibers are self-stretching due to differential shrinkage. The first component may comprise PTT having a pellet intrinsic viscosity of about 0.9 dL/g to about 1.25 dL/g, and the second component may comprise PET having an intrinsic viscosity of about 0.50 dL/g to about 0.80 dL/g A mixture of pellets, wherein the PET pellets included a blend of dried pellets (about 50 ppm moisture content) and undried pellets (about 2500 ppm moisture content).

In one embodiment, the moisture content of the undried PET pellets described herein may be from 300 ppm to about 5000 ppm. Examples of pellet moisture content include, but are not limited to: 300ppm, 310ppm, 320ppm, 330ppm, 340ppm, 350ppm, 360ppm, 370ppm, 380ppm, 390ppm, 400ppm, 410ppm, 420ppm, 430ppm, 440ppm, 450ppm, 460ppm, 470ppm, 480ppm, 490ppm, 500ppm , 510ppm, 520ppm, 530ppm, 540ppm, 550ppm, 560ppm, 570ppm, 580ppm, 590ppm, 600ppm, 610ppm, 620ppm, 630ppm, 640ppm, 650ppm, 660ppm, 670ppm, 680ppm, 690ppm , 780ppm, 790ppm, 800ppm, 810ppm, 820ppm, 830ppm, 840ppm, 850ppm, 860ppm, 870ppm, 880ppm, 890ppm, 900ppm, 910ppm, 920ppm, 930ppm, 940ppm, 950ppm, 960ppm, 970ppm, 980ppm, 990ppm, 1000ppm, 1010ppm, 1020ppm, 1010ppm, 1020ppm, 1010ppm, 1020ppm , 1060ppm, 1070ppm, 1080ppm, 1090ppm, 1100ppm, 1110ppm, 1120ppm, 1130 ppm, 1140ppm, 1150ppm, 1160ppm, 1170ppm, 1180ppm, 1190ppm, 1200ppm, 1210ppm, 1220ppm, 1230ppm, 1240ppm, 1250ppm, 1260ppm, 1270ppm, 1280ppm, 1290ppm1300ppm, 1310ppm, 1320ppm, 1330ppm, 1340ppm, 1350ppm, 1360ppm, 1370ppm, 1380ppm, 1390ppm1400ppm, 1410ppm, 1420ppm, 1430ppm, 1440ppm, 1450ppm, 1460ppm, 1470ppm, 1480ppm, 1490ppm1500ppm, 1510ppm, 1520ppm, 1530ppm, 1540ppm, 1550ppm, 1560ppm, 1570ppm, 1580ppm, 1590ppm1600ppm, 1610ppm, 1620ppm, 1630ppm, 1640ppm, 1650ppm, 1660ppm, 1670ppm, 1680ppm, 1690ppm1700ppm, 1710ppm, 1720ppm, 1730ppm, 1740ppm, 1750ppm, 1760ppm, 1770ppm, 1780ppm, 1790ppm1800ppm, 1810ppm, 1820ppm, 1830ppm, 1840ppm, 1850ppm, 1860ppm, 1870ppm, 1880ppm, 1890ppm1900ppm, 1910ppm, 1920ppm, 1930ppm, 1940ppm, 1950ppm, 1960ppm, 1970ppm, 1980ppm, 1990ppm2000ppm, 2010ppm, 2020ppm, 2030ppm, 2040ppm, 2050ppm, 2060ppm, 2070ppm, 2080ppm, 2090ppm2100ppm, 2110ppm, 2120ppm, 2130ppm, 2140ppm, 2150ppm, 2160ppm, 2170ppm, 2180ppm, 2190ppm2200ppm, 2210ppm, 2220ppm, 2230ppm, 2240ppm, 2250ppm, 2260ppm, 2270ppm, 2280ppm, 2290ppm 2400ppm, 2410ppm, 2420ppm, 2430ppm, 2440ppm, 2450ppm, 2460ppm, 2470ppm, 2480ppm, 2490ppm2500ppm, 2510ppm, 2520ppm, 2530ppm, 2540ppm, 2550ppm, 2560ppm, 2570ppm, 2580ppm, 2590ppm2600ppm, 2610ppm, 2620ppm, 2630ppm, 2640ppm, 2650ppm, 2660ppm, 2670ppm, 2680ppm, 2690ppm2700ppm, 2710ppm, 2720ppm, 2730ppm, 2740ppm, 2750ppm, 2760ppm, 2770ppm, 2780ppm, 2790ppm2800ppm, 2810ppm, 2820ppm, 2830ppm, 2840ppm, 2850ppm, 2860ppm, 2870ppm, 2880ppm, 2890ppm2900ppm, 2910ppm, 2920ppm, 2930ppm, 2940ppm, 2950ppm, 2960ppm, 2970ppm, 2980ppm, 2990ppm3000ppm, 3010ppm, 3020ppm, 3030ppm, 3040ppm, 3050ppm, 3060ppm, 3070ppm, 3080ppm, 3090ppm3100ppm, 3110ppm, 3120ppm, 3130ppm, 3140ppm, 3150ppm, 3160ppm, 3170ppm, 3180ppm, 3190ppm3200ppm, 3210ppm, 3220ppm, 3230ppm, 3240ppm, 3250ppm, 3260ppm, 3270ppm, 3280ppm, 3290ppm3300ppm, 3310ppm, 3320ppm, 3330ppm, 3340ppm, 3350ppm, 3360ppm, 3370ppm, 3380ppm, 3390ppm3400ppm, 3410ppm, 3420ppm, 3430ppm, 3440ppm, 3450ppm, 3460ppm, 3470ppm, 3480ppm, 3490ppm3500ppm, 3510ppm, 3520ppm, 3530ppm, 3540ppm, 3550ppm, 3560ppm, 3570ppm, 3580ppm, 3590ppm3600ppm, 3610ppm, 3620ppm, 3630ppm, 3640ppm, 3650ppm, 3660ppm, 3670ppm, 3680ppm, 3690ppm3700ppm, 3710ppm, 3720ppm, 3730ppm, 3740ppm, 3750ppm, 3760ppm, 3770ppm, 3780ppm, 3790ppm, 3800ppm, 3810ppm, 3820ppm, 3830ppm, 3840ppm, 3850ppm, 3860ppm, 3870ppm, 3880ppm, 3890ppm, 3900ppm, 3910ppm, 3920p pm, 3930ppm, 3940ppm, 3950ppm, 3960ppm, 3970ppm, 3980ppm, 3990ppm4000ppm, 4010ppm, 4020ppm, 4030ppm, 4040ppm, 4050ppm, 4060ppm, 4070ppm, 4080ppm, 4090ppm4100ppm, 4110ppm, 4120ppm, 4130ppm, 4140ppm, 4150ppm, 4160ppm, 4170ppm, 4180ppm, 4190ppm4200ppm, 4210ppm, 4220ppm, 4230ppm, 4240ppm, 4250ppm, 4260ppm, 4270ppm, 4280ppm, 4290ppm4300ppm, 4310ppm, 4320ppm, 4330ppm, 4340ppm, 4350ppm, 4360ppm, 4370ppm, 4380ppm, 4390ppm4400ppm, 4410ppm, 4420ppm, 4430ppm, 4440ppm, 4450ppm, 4460ppm, 4470ppm, 4480ppm, 4490ppm4500ppm, 4510ppm, 4520ppm, 4530ppm, 4540ppm, 4550ppm, 4560ppm, 4570ppm, 4580ppm, 4590ppm4600ppm, 4610ppm, 4620ppm, 4630ppm, 4640ppm, 4650ppm, 4660ppm, 4670ppm, 4680ppm, 4690ppm4700ppm, 4710ppm, 4720ppm, 4730ppm, 4740ppm, 4750ppm, 4760ppm, 4770ppm, 4780ppm, 4790ppm4800ppm, 4810ppm, 4820ppm, 4830ppm, 4840ppm, 4850ppm, 4860ppm, 4870ppm, 4880ppm, 4890ppm4900ppm, 4910ppm, 4920ppm, 4930ppm, 4940ppm, 4950ppm, 4960ppm, 4970ppm, 4980ppm, 4990ppm, and 5000ppm.

The weight ratio between dry and undried pellets can vary from 0 to 100%. Examples of % weight ratios of dried to undried pellets include, but are not limited to: 0:100, 5:95, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40 : 60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, and 100: 0.

In one embodiment, the moisture content of the undried PET pellets (as described above) can be varied in combination with changing the % weight ratio of dried and undried pellets (as described above) to control the final outcome of the subsequently formed bicomponent fibers. Puffing measurement (% curl).

In another embodiment of the bicomponent fiber, the first component can comprise PTT and the second component can comprise PET, wherein the first component can have about 0.9 dL/g to about 1.25 dL/g of PTT pellets Intrinsic viscosity and PTT pellets can be extruded at about 245 ° C to 265 ° C, and the first The two-component can have an intrinsic viscosity of the PET pellets of about 0.50 dL/g to about 0.80 dL/g and the PET pellets can be undried (about 2500 ppm moisture content) and extruded at a temperature of about 250°C to 280°C .

In one embodiment, the moisture content of the undried PET pellets may be from 300 ppm to about 5000 ppm.

Extrusion temperatures for the undried PET pellets may include, but are not limited to, 250°C, 255°C, 260°C, 265°C, 270°C, and 280°C.

In one embodiment, changing the moisture content of the undried PET pellets (as described above) may be combined with changing the extrusion temperature of the undried PET pellets (as described above) to control the final bulking of the subsequently formed bicomponent fibers Measured value (% curl).

In embodiments of the method herein, a PET extruder may feed a supply of dried PET pellets and a supply of undried PET pellets at a desired ratio as described herein, with the difference between undried and dried PET pellets The ingredients are added to the extruder separately rather than premixed.

In embodiments of the method herein, the drying conditions of the PET pellet supply hopper can be adjusted to provide the necessary moisture for hydrolysis. For example, during two-component manufacturing, PET pellets are typically dried to 50 ppm moisture. By "under-drying" the PET pellets (eg, to 300 ppm moisture), the retained pellet moisture can promote hydrolysis in the extruder to achieve the desired lower I.V.. In this way, the desired PET IV can be "dial-in" into the spinning process.

In embodiments of the method herein, the PET extruder may be supplied with a vacuum system to control the PET I.V.. In this way, little or no drying of high IV PET wet pellets can be "trimmed" by the amount of vacuum supplied to achieve the desired I.V.

In embodiments of the method herein, the PET pellets can be dried (about 50 ppm) in the manner herein, and a small amount of water can be injected into the heated extruder to affect the desired degree of hydrolysis and subsequent I.V. value.

The in-line hydrolysis method described herein is an effective method for controlling I.V. It may be necessary to use the offline techniques described herein. For example, the hydrolysis methods described herein can be practiced off-line on an extruder independent of fiber spinning. The hydrolyzed PET exiting the extruder can have the desired I.V. and can then be re-pelletized. The re-granulated pellets with the desired I.V. can then be dried in the usual way without the need for in-line control of the I.V..

Tensile measured (% crimp) values for bicomponent fibers made by the methods disclosed herein can be increased by about 10% to about 85%. Examples of increased stretch measurements include, but are not limited to, 10%, 12%, 17%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% , 70%, 75%, 80%, and 85%.

In another embodiment of the bicomponent fiber, the first component can comprise PTT and the second component can comprise PET, wherein the first component can have about 0.9 dL/g to about 1.25 dL/g of PTT pellets Intrinsic viscosity and PTT pellets may be extruded at 260°C, and the second component may have an intrinsic viscosity of PET pellets of about 0.50 dL/g, wherein the PET pellets may contain dry pellets (about 50 ppm moisture) and untreated A blend of dry pellets (about 2500 ppm moisture). The weight ratio between dry and undried pellets can vary from 0 to 20%.

The first and second components may independently be PET or co-PET and PTT or blends of PTT and PET or co-PET may be present in the two components in a weight ratio of about 80:20 to about 20:80 in the fiber. For example, the weight ratio of the first component and the second component may be 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:5 60, 35:65, 30:70, 25:75, 20:80, or any ratio within this range.

In one embodiment, the tensile measured (% crimp) value of bicomponent fibers made by the methods disclosed herein may not need to be increased but controlled by changing: moisture content of the undried component; The ratio of dry and undried pellets, and/or the extrusion temperature of a particular component. Adding tensile measurements and controlling them depends on the type of polymer used to make a particular bicomponent fiber.

Various additives can be added to one or both of the polymers of the first and second components. Such additives include, but are not limited to, lubricants, nucleating agents, antioxidants, UV stabilizers, pigments, dyes, antistatic agents, soil resistance agents, stain resistance agents, antimicrobial agents, and flame retardants.

Bicomponent fibers can be made by delivering polymers to a spinneret in a desired volume or weight ratio. While any conventional multicomponent spinning technique can be used, exemplary spinning apparatus and methods for making bicomponent fibers are described in US Patent No. 5,162,074 to Hills (herein incorporated by reference in its entirety).

The bicomponent fibers described herein can be in a side-by-side ("S/S") or eccentric sheath-core ("S/C") configuration. Bicomponent fibers can be made into various cross-sectional shapes, such as circular, triangular, trilobal, fan-shaped, or other shapes, by using spinnerets specific for each shape, for example, as disclosed in US Pat. No. 6,803,102, which utilizes Incorporated herein by reference in its entirety.

Also disclosed herein are articles comprising bicomponent fibers made by the methods herein. Articles include, but are not limited to, garments, fabrics, fully drawn yarns (FDY), partially oriented yarns (POY), staple fibers, non-woven fibers, non-woven fabrics, and carpets.

In one embodiment, disclosed herein is a carpet having face fibers comprising bicomponent fibers made by the methods disclosed herein.

For use in carpets, the bicomponent fibers disclosed herein can have a denier of about 300 to about 1400 grams per denier. Useful denier/filament can be from about 2 to about 20.

The bicomponent fibers disclosed herein can be used with all other types of synthetic and natural fibers used to make carpets. Carpets can be made by machine or hand tufting, weaving and hand knotting. Examples include 1) broad rugs (also known as whole house rugs), where tufted rugs are made in long continuous lengths several meters wide for domestic and commercial applications; 2) tiled rugs, which are available in various sizes 3) household rugs; or 4) mats for vehicle and building entrances designed to trap dirt underfoot before entering the building.

Any method known in the art for making carpets from fibers can be used to make the carpets described herein. Typically, the bicomponent fibers disclosed herein can be used in the same carpet manufacturing process using other synthetic fibers and natural fibers. Bicomponent fibers can be used in carpet manufacturing by themselves (ie, as "singles" yarns), or plied with more of the same bicomponent fibers or other fiber types (eg, nylon, polypropylene, polyester) together to increase the denier. If desired, the single and plied fibers can be entangled with air jets prior to plying, and can also be heat set by machines specifically designed to heat set the physical properties of single and tufted yarns.

An example of a heat setting machine suitable for this purpose is manufactured by Superba® (Muhouse, France). Whether the bicomponent fibers are air-entangled, plied, or heat-set as desired, the fibers can be tufted into standard nonwoven or woven backing sheets typical of the carpet industry. The face fiber loops in a tufted carpet can be cut to provide a cut loop carpet. After tufting, adhesive is often applied to the back of the carpet (ie, the side opposite the face fibers) to hold the tufts in place. Additional backing layers can also be added to the back of the rug. The adhesive layer may contain fillers or flame retardants, depending on the specific carpet end use. The carpet can then be dyed by standard processes common to the carpet manufacturing industry; alternatively, pigments can be added to the bicomponent fibers and/or companion fibers during fiber extrusion to impart color to the finished fabric. In addition, the face yarn can be treated with materials designed to impart fire resistance, antistatic properties, or resistance to soiling and dirt. The finished carpet is often dried to remove water remaining in the dyeing process.

The manufacturing method described above is a typical method for wide tufted carpets. Variations of this method known in the industry can be used in the production of rugs, carpet tiles and car mats.

The face fibers comprising bicomponent fibers may have a circular or non-circular cross-section, such as a trilobal shape.

example

The present disclosure is further defined in the following examples. It should be understood that these examples, while indicating certain embodiments, are given by way of illustration only. From the above discussion and this example, one of ordinary skill in the art can ascertain the essential characteristics of the disclosure, and without departing from the spirit and scope of the disclosure, can make various changes and modifications to adapt it to various uses and conditions.

As used herein, "Comp. Ex." means Comparative Example; "Ex." means Example; "No." means number; "%" means percentage or percentage; "IV" means intrinsic viscosity; "dL/g" means deciliters per gram; "g" means grams; "mg" means milligrams; "°C" means degrees Celsius; "°F" means degrees Fahrenheit; Temperature; "min" is minutes; "h" is hours; "sec" is seconds; "lb" is pounds; "kg" is kilograms; "mm" is millimeters; "m" is meters; "gpl" is grams/ Liters; "m/min" is meters per minute; "mol" is moles; "kg" is kilograms; "ppm" is parts per million; "wt" is weight; "dpf" is denier/filament ; "gpd" or "g/d" means grams per denier; "dtex" means cent tex; "dN/tex" means cent newton/tax; "mL" means milliliter; "IV" means Refers to intrinsic viscosity;

Unless otherwise indicated, all materials are used as received.

testing method

Measurement of crimp shrinkage after heating (% CCa) - crimp shrinkage method:

The post-heat crimp shrinkage (% CCa, also referred to as tensile value) was determined according to the methods described herein. Using a reel winch at a tension of about 0.1 gpd (0.09 dN/tex), each instance was The fibers of the and comparative examples were independently formed into hanks of about 5000 +/- 5 total denier (5550 dtex). The length of the hank is then halved by folding the hank in half to fit inside the oven used for heat setting. The folded skein was suspended from the hook at its midsection and conditioned at 70 +/- 1°F (21 +/- 1°C) and 65 +/- 2% relative humidity for at least 16 hours. The folded hank is then suspended from the rack substantially vertically by hooks at its middle portion, and a 1.5 mg/den (1.35 mg/dtex) weight is suspended from the hank through two loops of the folded hank bottom of. The weighted skein was then heated in an oven at 250°F (121°C) for 5 minutes, after which the rack and skein were removed and allowed to cool for 5 minutes before being heated at 70°F +/- 1°F (21 +/- - 1°C) and 65% +/- 2% relative humidity for at least 2 hours, with a 1.5 mg/den weight left on the skein for the remainder of the test. The length of the skein was measured to within 1 mm and recorded as "Ca". Next, a weight of 1000 g was suspended from the bottom of the hank to balance, and the length of the hank was measured within 1 mm and recorded as "La". Calculate the curl shrinkage "CCa" value (%) after heating according to the following formula:

%CCa=100×(La-Ca)/La

Determination of Intrinsic Viscosity

Intrinsic viscosity (IV) was determined using a Viscoteck Y 501C forced flow viscometer (Malvern Corporation, Houston Texas, USA). A 0.15 g sample was weighed into a 40 mL glass vial containing 30 mL of solvent (phenol/1,1,2,2-tetrachloroethane (60/40 weight percent)) and a stir bar. The samples were then placed in a heat block preheated at 100°C, heated and stirred for 30 minutes, removed from the block and cooled for 30-45 minutes before being placed in the autosampler rack of the viscometer. The samples were then analyzed by ASTM method D5225-92 (Standard Test Method for Measuring Solution Viscosity of Polymer With A Differential Viscometer).

Preparation of polymers

Two grades of PTT homopolymer pellets were obtained from E.I du Pont de Nemours and Company, Wilmington, Delaware USA. One grade had an IV of 1.02 dL/g and the second grade had an IV of 0.92 dL/g. PET homopolymer pellets were obtained from Sinopec Shanghai Petrochemical Company, Ltd. Shanghai, PRC, Shanghai, China, and had an IV of 0.50 dl/g. PET copolymer (containing 1.9 mol% isophthalic acid) pellets having an IV of 0.80 dl/g were obtained from NanYa Plastics Corporation, Livingston New Jersey, USA material.

In preparation for melt spinning, the PET and PTT pellets were dried under nitrogen for 15 hours in a vacuum oven at 25 inches of mercury vacuum and a temperature of 120°C. Under these conditions, both PET and PTT pellet moisture was reduced to about 50 ppm. The dried pellets were transferred directly to the nitrogen purged feed hopper of the spinner. In the example where a mixture of dried and undried PET pellets was used, the undried pellets were taken directly from the bag and had a residual moisture content of about 2500 ppm.

Fiber preparation

The first and second components of bicomponent fibers are melt spun using processes and equipment generally suitable for the spinning of side-by-side and eccentric sheath/core bicomponent fibers, e.g., as in US Pat. No. 6,641,916 B1, US Disclosed in Patent No. 6,803,102 and US Patent No. 7,615,173 B2, which are incorporated herein by reference in their entirety.

In spinning the bicomponent fibers of the examples, the polymers were melted in a pair of Werner & Pfleiderer co-rotating 28 mm twin-screw extruders Has a capacity of 0.5 to 40 lb/hr (0.23 to 18.1 kg/hr). An extruder (herein referred to as the East Extruder) to melt 1) PET pellets (dried to about 50 ppm) or 2) A mixture of PET pellets, some of which were dried to a residual moisture content of about 50 ppm and the remaining pellets were undried and had a residual moisture content of about 2500 ppm. A second extruder (herein referred to as the West extruder) was used to melt the PTT pellets dried to about 50 ppm residual moisture. The temperatures of the west extruder, spinning block and east extruder are listed in the examples. Each extruder feeds a spin pack containing a concave spinneret. The spinnerets used were post-coalesced, side-by-side bicomponent spinnerets having thirty-four pairs of capillaries arranged in a circle, the interior angle between each pair being 30 degrees, and the diameter of the capillaries being 0.64 mm, and The capillary length is 4.24mm.

The bicomponent filaments exiting the spinneret were cooled by means of cross-flow quench air at nominally 20°C and 0.5 mm/s face velocity. The filaments are then advanced to dual feed rolls that operate at about 800 to 1200 meters per minute, depending on the draw ratio. A finish applicator was used to apply lubricant to the filament tow between the spinneret and the feed roll. To affect stretching, the feed roll is typically heated to 70°C. The filament bundle is then accelerated to an annealing roll, which operates at a speed of about 3000 to 3600 meters per minute depending on the desired draw ratio, and the annealing roll temperature is typically 170°C. The annealed bicomponent fibers were then advanced to two sets of double letdown rolls operating at room temperature before being wound up on a Barmag SW6 600 winder. The fibers have a snowman (oblong) cross-sectional shape. The bicomponent fibers in all examples were 75 denier, 34 filaments.

Changes in Moisture Content of Comparative Example A and Examples 1-3 Pellets

Comparative Example A illustrates a typical manufacturing process for making PET/PTT bicomponent fibers, wherein 0.50 I.V. PET pellets were dried to about 50 ppm residual moisture and then extruded by an East extruder at 270°C, and The 1.02 I.V. PTT pellets were dried to about 50 ppm residual moisture and extruded by a western extruder at 260°C. The ratio of PET to PTT in the bicomponent fiber was 50/50. The measured tensile value of 48% was within the typical range for commercial bicomponent fibers.

Examples 1-3 illustrate the use of in-line hydrolysis to control the amount of fiber draw produced in bicomponent fibers (using 0.80 I.V. PET). In Examples 1 to 3, 1.02 IV PTT was dried to about 50 ppm and extruded at the indicated temperature. The only variable in these examples was the amount of undried PET (about 2500 ppm residual moisture) mixed with the dried PET. As evident in Example 1, drying 0.80 IV to the same extent as PTT (eg, 50 ppm moisture) resulted in fibers with little draw. The relatively small difference in pellet I.V. between PET and PTT does not contribute to differential fiber shrinkage or percent stretch. In Example 2, the ratio of undried to dried PET pellets was 10/90 weight percent. Under these process conditions, residual moisture in the undried polymer promotes the hydrolysis of 0.80 I.V. PET in the heated extruder. The effect of hydrolysis can be seen by reducing the fill pressure from 950 psi to 370 psi. This reduction in filling pressure is associated with a reduction in polymer melt viscosity, a reduction in polymer molecular weight, an increase in differential shrinkage, and an increase in fiber draw. The example shows the effect of increasing the undried to dried PET ratio to 20/80 weight percent, where additional residual moisture further contributes to reductions in fill pressure and melt viscosity and increases in differential shrinkage and stretch percentages.

[Table 1]. Process conditions and tensile values of Comparative Example A and Examples 1 to 3

Example 4-7 Variation of extrusion temperature

Examples 4-7 illustrate the use of in-line hydrolysis to control the amount of fiber draw produced in bicomponent fibers by varying the temperature at which hydrolysis occurs in a PET extruder. In Examples 4-7, 0.92 IV PTT was dried to about 50 ppm and 0.80 IV PET was 100% undried (ie, about 2500 ppm residual moisture). The polymer ratio between PET and PTT in the fibers was 70/30 weight percent. The degree of hydrolysis was controlled by the PET extruder temperature rather than by the concentration of the undried pellets. The chemical reaction between the hydrolyzed polyester and the residual moisture, and the degree of the reaction increases as the extrusion temperature increases. In Example 4, the PET extruder was set at 250°C. exist At this relatively low temperature, little hydrolysis occurs, the fill pressure is high, the molecular weight remains high, little differential fiber shrinkage occurs, and the fiber stretch is low (10.8%). In Example 5, the PET extruder temperature was increased by 10°C to 260°C. At this higher extruder temperature, hydrolysis increased, filling pressure decreased, molecular weight decreased, fiber differential stretch increased and fiber stretch increased to 22%. A comparison of Examples 4 and 5 shows that increasing the PET by 10°C more than doubles the fiber draw. Examples 6 and 7 show that increasing the PET extruder to 270°C and 280°C increased the tensile measurements to 27.2% and 50.5%, respectively. These examples show the important effect of extrusion temperature on the degree of hydrolysis and fiber properties.

[Table 2]. Process conditions and tensile values of Examples 4 to 7

Examples 8-10 Stretching Formation

Examples 8-10 illustrate the use of in-line hydrolysis to produce bicomponent fibers with higher draw values than those obtained by conventional methods. The 0.50 I.V. PET preferred by manufacturers of PET/PTT bicomponent fibers is generally the lowest IV PET that can be produced commercially because of the difficulty in pelletizing low IV PET. Due to the need to increase stretch to an order of magnitude greater than commonly available 0.50 IV PET, reducing PET IV by hydrolysis is an option. Example 8 shows the process and results for a 50/50 weight ratio PET/PTT bicomponent fiber made with fully dried (about 50 ppm residual moisture) 0.50 I.V. PET and 1.02 IV PTT. Examples 9 and 10 show draw results for fibers made by mixing dried PET with 5% and 10% undried 0.50 I.V. PET (about 2500 ppm residual moisture), respectively. The tensile values of 65.8% and 69.3% are much higher than commercially available fibers. In these instances, the additional residue Moisture further contributed to the reduction of filling pressure and melt viscosity and the increase of differential shrinkage and stretch percentage.

[Table 3]. Process conditions and tensile values of Examples 9 to 11

Claims (26)

A method of making bicomponent fibers, the method comprising: a) extruding the first and second components on a spinning machine capable of producing two or more independent melt streams; b) combining the melt stream in a spinneret suitable for making bicomponent fibers; c) quenching the bicomponent fibers produced in step (b) in air; d) drawing and heat setting the quenched bicomponent fibers; and e) winding the bicomponent fibers in step (d) by any suitable means; wherein the first extruded component has a lower moisture content than the second extruded component. The method of claim 1, wherein the first and second components are independently selected from the group consisting of polyester, nylon, and combinations thereof. The method of any one of claims 1 to 2, wherein the first and second components are independently selected from poly(trimethylene terephthalate), poly(ethylene terephthalate) ), poly(butylene terephthalate), and a polyester of the group consisting of copolymers thereof, and the second component is selected from the group consisting of poly(trimethylene terephthalate), poly(terephthalate) Polyesters of the group consisting of ethylene dicarboxylate), poly(butylene terephthalate), and copolymers thereof. The method of any one of claims 1 to 3, wherein the first component is poly(ethylene terephthalate) and the second component is poly(trimethylene terephthalate) . The method of any one of claims 1 to 4, wherein the first component has a moisture content of about 10% to about 20% and the second component has a moisture content of about 90% to about 80% . The method of any one of claims 1 to 5, wherein the first component has a moisture content of about 50 ppm or less and the second component has a moisture content of greater than about 50 ppm. The method of claim 1, wherein with the bicomponent fibers produced by steps (a) to (e) - wherein the first extruded component has no more components than the second extruded component The low moisture content - compared to about 10% to about 85% increase in tensile measurements for the bicomponent fibers produced in step (e). The method of claim 7, wherein the stretch measurement increase is selected from the group consisting of 12%, 17%, and 40%. The method of claim 1 wherein the first and second components of the bicomponent fibers are present in a weight percent ratio of 20:80 to 80:20. The method of claim 1, wherein the bicomponent fibers are in a configuration selected from the group consisting of side-by-side, eccentric sheath-core configurations, and trilobal configurations. The method of claim 11, wherein the bicomponent fiber of step (e) has a crimp shrinkage after heating, determined according to a crimp shrinkage method, from about 10% to about 85%. The method of claim 1 wherein the extruder temperature of one of the components in step (a) is from about 240°C to about 320°C. The method of claim 12, wherein the extruder temperature of one of the two extruded components in step (a) is selected from the group consisting of 260°C, 270°C, 280°C, 290°C, 300°C, 310°C ℃, and the group consisting of 320℃. An article of clothing comprising bicomponent fibers made by the method of claim 1 . A fabric comprising bicomponent fibers made by the method of claim 1 . A fully drawn yarn comprising bicomponent fibers produced by the method of claim 1 . A partially oriented yarn comprising bicomponent fibers produced by the method of claim 1 . A staple fiber comprising bicomponent fibers produced by the method of claim 1 . A carpet, the face fibers of which comprise bicomponent fibers produced by the method of claim 1 . The carpet of claim 19, wherein the bicomponent fibers are in a configuration selected from the group consisting of side-by-side, eccentric sheath-core configurations, and trilobal configurations. The carpet of claim 20, wherein the face fibers further comprise at least one additional fiber selected from the group consisting of bulked continuous filaments, synthetic staple fibers, and natural fibers. The carpet of claim 21, wherein the at least one additional fiber is a bulked continuous filament, and the bulked continuous filament comprises nylon, polypropylene, or polyester. The carpet of claim 21, wherein the at least one additional fiber is a synthetic staple fiber, and the synthetic staple fiber comprises nylon or polyester. The carpet of claim 21, wherein the at least one additional fiber is a natural fiber, and the natural fiber comprises wool, silk, or cotton. A nonwoven fiber comprising bicomponent fibers produced by the method of claim 1. A nonwoven fabric comprising bicomponent fibers produced by the method of claim 1.