JP2023506733A - Carpet made from bicomponent fibers containing self-lofting PTT - Google Patents

Abstract

A carpet, the surface fibers of which include a first component of a poly(ethylene terephthalate) homopolymer or a poly(ethylene terephthalate) copolymer and a poly(trimethylene terephthalate) polymer or poly(trimethylene terephthalate) and poly(ethylene terephthalate). and a second component of a blend with a homopolymer or a poly(ethylene terephthalate) copolymer, wherein the bicomponent fibers are self-lofting due to differential shrinkage. An improved method for making yarns for making carpets, wherein the surface fibers of the carpet include a first component of poly(ethylene terephthalate) homopolymer or poly(ethylene terephthalate) copolymer and poly(trimethylene terephthalate). or a second component of a blend of poly(trimethylene terephthalate) and a poly(ethylene terephthalate) homopolymer or poly(ethylene terephthalate) copolymer. .

Description

FIELD OF THE DISCLOSURE The present disclosure relates to carpets, and more particularly to carpets, the surface fibers of which comprise self-lofting poly(trimethylene terephthalate) (PTT)-containing bicomponent fibers.

In modern carpet manufacture, fibers with a high level of loft can be defined as having enhanced covering power or apparent volume compared to non-bulked or "flat" fibres. It is common to use synthetic polymers (eg, nylon, polyester, polypropylene) to make them. These bulked continuous fibers (“BCFs”) are typically produced on spinners equipped with high temperature/high pressure jets and cooling drums specially designed to mechanically impart bulk to the fibers. It is a monocomponent fiber. This process has several drawbacks. The high temperature, pressure, and turbulence of the fibers in the jet can damage the fiber filaments and adversely affect the physical properties of the fibers. Furthermore, the need to impart bulk by a jet/drum process has been driven by other spinning processes that do not require mechanical bulking, i.e. fully oriented yarn ("FDY") or partially oriented yarn ("POY"). Inevitably, the fiber production rate is lowered compared to the flat yarn.

One way to characterize textile fibers is the amount of crimp in the fiber. "Crimp" refers to the waviness of a fiber and can be expressed as a number per unit length. The amount of crimp, also referred to herein as "crimp shrinkage", can be expressed by comparing the stretched length of the fiber under load to the crimped length of the unloaded fiber. . The amount of crimp in the fiber can be of natural origin (eg, wool) or can be imparted to the synthetic fiber during manufacture to suit the desired end use. Differential shrinkage using bulking jets with air and heat (BCF), or twisting/untwisting POY in a false twister into draw-textured yarn (DTY), or side-by-side or eccentric sheath/core bicomponent fibers It is possible to cause crimping. A low degree of crimp corresponds to textile fibers with increased loft or loft and is desirable when fabric opacity or covering power is important. Alternatively, a high degree of crimp results in fibers with significant levels of stretch and recovery, which are appreciated in apparel applications.

In carpet applications, a low degree of crimp is desirable to impart loft without significantly developing stretchability. A self-crimping lofty yarn comprising bicomponent filaments for fabrics is described in US Pat. In apparel fabrics, the crimp properties of side-by-side and eccentric sheath/core type bicomponent fibers are usually maximized to provide high levels of stretchability to the fibers and resulting fabrics. US Pat. No. 6,200,400 to Talley et al. on Oct. 12, 2004 illustrates the production of bicomponent fibers with asymmetric fiber cross-sections and is incorporated herein in its entirety.

US Patent Application Publication No. 2004/0020001 to Talley et al. on Dec. 12, 2000 discloses self-hardening yarns made from bicomponent fibers that form helical crimps that lock the twist and create bulk. . The use of such yarns in carpets and textiles is also disclosed. Various polymers are disclosed such as poly(ethylene terephthalate) (“PET”), poly(butylene terephthalate) (“PBT”), polypropylene, nylon, and the like. However, the use of poly(trimethylene terephthalate) (PTT) is not disclosed.

U.S. Patent No. 5,301,303 Howell et al., U.S. Patent No. 5,300,000 Roark et al., and U.S. Patent No. 6,300,500 Chuah; U.S. Patent No. 7, Scott et al.; Carpets are described which are non-bicomponent but all of which are incorporated herein by reference.

The surface fibers of the carpet are poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co-PET) first component and poly(trimethylene terephthalate) (PTT) or PTT and PET homopolymer or a second component of a blend with a PET copolymer (co-PET), wherein the bicomponent fibers are made from bulk continuous homofilaments in which the surface fibers of the carpet are mechanically bulked; In contrast, disclosed herein is a carpet that is self-lofting due to differential shrinkage.

U.S. Pat. No. 7,790,282 U.S. Pat. No. 6,803,102B1 U.S. Pat. No. 6,158,204 U.S. Pat. No. 5,645,782 U.S. Pat. No. 6,109,015 U.S. Pat. No. 6,113,825 WO 99/19557 pamphlet

H. Modlich, "Experience with Polyesters Fibers in Tufted Articles of Heat-Set Yarns, Chemiefasern/Textilind. 41/93, 786-94 (1991) H. Chuah, "Corterra Poly (trimethylene terephthalate)--New Polymeric Fibers for Carpets", The Textile Institute Tifcon '96 (1996) (visited at http://www.shellchemicals.com/0, 810, 810, 81terra/0). Possible)

In a first embodiment, the surface fibers comprise a first component of poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co-PET) and a poly(trimethylene terephthalate) (PTT) polymer. or bicomponent fibers comprising PTT and a second component of a blend of PET homopolymer or PET copolymer (co-PET), wherein the surface fibers of the carpet are made from bulk continuous homofilaments mechanically bulked. In contrast to carpet, disclosed herein is carpet in which the bicomponent fibers are self-lofting due to differential shrinkage.

In a second embodiment, the bicomponent fibers may be in a side-by-side arrangement or an eccentric sheath/core arrangement.

In a third embodiment, the first and second components of the bicomponent fiber can be present in a weight ratio ranging from 80:20 to 20:80.

In a fourth embodiment, the self-lofting bicomponent fibers disclosed herein have a post-heat crimp shrinkage of 30% or less determined according to the crimp shrinkage method disclosed herein.

In a fifth embodiment, the face fibers of the carpet comprise a first component of poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co-PET) and poly(trimethylene terephthalate) (PTT). or an improved process for making carpet-making yarn comprising self-lofting bicomponent fibers comprising PTT and a second component of a blend of PET homopolymer or PET copolymer (co-PET), comprising: Said process:
a) extruding the two components through a spinner capable of producing two or more independent melt streams;
b) combining the melt streams in a suitable spinneret to make bicomponent fibers;
c) quenching in air the self-lofting bicomponent fiber produced in step (b);
d) drawing and heat setting the self-lofting bicomponent fiber; and e) winding the self-lofting bicomponent fiber by a means suitable for subsequent processing into carpet, comprising:
A process is disclosed in which self-bulking bicomponent fibers comprise steps that do not require a mechanical bulking step.

In a sixth embodiment, the bicomponent fibers may be in a side-by-side or eccentric sheath-core arrangement.

In a seventh embodiment, the first and second components of the bicomponent fiber can be arranged in weight ratios ranging from 80:20 to 20:80%.

In an eighth embodiment, the self-lofting bicomponent fibers disclosed herein have a post-heat crimp shrinkage of 30% or less determined according to the crimp shrinkage method disclosed herein.

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

As used herein, the terms "embodiment" or "disclosure" are not meant to be limiting, but to the implementations defined in the claims or described herein. Applies generally to any of the forms. These terms are used interchangeably herein.

A number of terms and abbreviations are used in this disclosure. Unless specifically stated otherwise, the following definitions apply.

The indefinite article "a" preceding an element or component is intended to be open-ended as to the number of instances (ie, occurrences) of that element or component. Thus, "a" and "the" should be read to include one or at least one, and singular forms of elements or components also refer to plural unless the number is expressly meant to be singular. Including shape.

The term "comprising" means the presence of a feature, integer, step or component mentioned in a claim, but not one or more other features, integers, steps, components or groups thereof. does not exclude the presence or addition of The term "comprising" shall include embodiments encompassed by the terms "consisting essentially of" and "consisting of." Similarly, the term "consisting essentially of" shall include embodiments encompassed by the term "consisting of."

Where present, all ranges are inclusive and combinable. For example, if a range of "1 to 5" is recited, the ranges recited are "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 ˜3 and 5″ and so forth.

As used herein in conjunction with numerical values, the term “about” refers to a range of ±0.5 of the numerical value, unless the term is specifically defined in context. For example, the phrase "a pH value of about 6" refers to a pH value between 5.5 and 6.5, unless the pH value is specifically defined.

Any upper numerical limit given throughout this specification is intended to include every lower numerical limit, as if such lower numerical limits were expressly written herein. Every numerical lower limit given throughout this specification will include every higher numerical limit, as if such higher numerical limits 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 all such narrower numerical ranges were expressly written herein. It will include narrow numerical ranges.

As used herein, the term "bicomponent fiber" is composed of different polymer types, the same polymer type but with different intrinsic viscosities, or blends of two or more polymers, and the same filament Refers to fibers composed of two different polymer components extruded from the same spinneret with both polymers within. Bicomponent fibers may also be referred to as bicomponent fibers and the terms can be used interchangeably.

The term "BCF" refers to bulk or bulked continuous homofilament. Essentially one long continuous strand of fiber is used to make carpet. The terms "bulk" and "bulked" 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. It can be a tufted carpet or a woven fabric. As used herein, the term "carpet" includes wall-to-wall carpets, tile carpets, rugs, vehicle and building entrance mats, such as those designed to trap foot dirt. do.

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

As used herein, the term "face fiber" refers to the fiber content of the carpet including what is visible to an observer. The surface fibers consist primarily of yarns, and these yarns can be cut, looped, cut and looped, or any number of types known to those skilled in the art.

The term "copolymer" refers to a polymer composed of a combination of more than one species of monomer. Copolymers can form the basis of several types of manufactured fibers.

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

The term "crimp shrinkage" is a measure of fiber crimp and refers to the shrinkage of yarn length from a fully stretched state (ie, a state in which the filaments are substantially straightened). This is due to the formation of crimps in individual filaments under certain conditions of crimp development. It is expressed as a percentage of stretched length. Crimp shrinkage can be measured before and/or after treating the fiber, e.g., by heating, to develop a crimp partially or fully; It is more interesting and provides more information because it includes the generated crimp. Unless otherwise specified, crimp shrinkage values disclosed herein are post-heating 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 material, either natural or synthetic, that forms the basic element of fabrics and other textile structures. It is characterized by having a length at least 1000 times its diameter or width. Generally, textile fibers are units that can be spun into yarn or made into fabric by a variety of processes including weaving, knitting, braiding, felting and twisting. A fiber is characterized by its denier (weight in grams per 9000 meters of fiber) and the number of filaments contained in the fiber.

"Filament" refers to a fine thread or continuous strand of fiber. There are two types of filaments: mono-filaments and multifilaments. Filaments are characterized by their denier per filament (“dpf”).

"Monofilament" means a filament composed of one polymer type.

"Staple" refers to either natural fibers or cut lengths 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 producing textiles such as carpets on specialized multi-needle machines. A "tuft" is a collection of soft threads that are drawn into a fabric and protrude from the surface in the form of cut threads or loops. Cut or uncut loops form the surface of the tufted or woven carpet.

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

The term "quenching" refers to rapid, rapid cooling in water, oil, or air to obtain specific physical properties or properties of matter.

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 is also referred to as poly(ethylene terephthalate) homopolymer. be. As used herein, the term "poly(ethylene terephthalate) copolymer" or "co-PET" includes repeating units derived from ethylene glycol and terephthalic acid (or equivalents), and additionally isophthalic acid ( IPA) or a polymer that also contains at least one additional unit derived from an additional monomer such as cyclohexanedimethanol (CHDM). Poly(ethylene terephthalate) copolymers can contain from about 1 mol % to about 30 mol % additional monomer, such as from about 1 mol % to about 15 mol % 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 referred to as poly(butylene terephthalate) homopolymer. As used herein, the term "poly(butylene terephthalate) copolymer" comprises repeat units derived from 1,4-butanediol and terephthalic acid, and further comprises additional monomers such as those disclosed herein. refers to polymers that also contain at least one additional unit derived from the comonomer for the PTT copolymer used.

The term "poly(trimethylene terephthalate)" or PTT refers to a polyester produced by polymerizing 1,3-propanediol and terephthalic acid. PTT is distinguished by its 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 of substantially only 1,3-propanediol and terephthalic acid (or equivalent). The term "poly(trimethylene terephthalate)" also includes PTT copolymers, thereby comprising repeat units derived from 1,3-propanediol and terephthalic acid (or equivalents), and further derived from additional monomers. It means a polymer containing at least one additional unit. Examples of PTT copolymers include copolyesters made using three or more reactants that each have two ester-forming groups. For example, copoly(trimethylene terephthalate) is a compound in which the comonomers used to make the copolyester are linear, cyclic, and branched aliphatic dicarboxylic acids having 4 to 12 carbon atoms, such as butanedioic acid. , pentanedioic acid, hexanedioic acid, dodecanedioic acid, and 1,4-cyclo-hexanedicarboxylic acid); -naphthalenedicarboxylic acids); linear, cyclic, and branched aliphatic diols of 2 to 8 carbon atoms (other than 1,3-propanediol, such as ethanediol, 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 4 Aliphatic and aromatic ether glycols having ∼10 carbon atoms (e.g., hydroquinone bis(2-hydroxyethyl) ether, or poly(ethylene ether) glycols having a molecular weight of less than about 460, including diethylene ether glycol) can be used when selected from the group consisting of Comonomers are typically present in the copolyester in concentrations ranging from about 0.5 mole percent to about 15 mole percent, and can be present in amounts up to about 30 mole percent.

The term "Triexta" refers to the generic term for PTT, a sub-genus of polyesters. "Triexta" and "PTT" may be used interchangeably herein.

Poly(trimethylene terephthalate) typically has an intrinsic viscosity of greater than or equal to about 0.5 deciliters/gram (dl/g) and typically less than or equal to about 2 dl/g. The poly(trimethylene terephthalate) preferably has an intrinsic viscosity that is about 0.7 dl/g or greater, more preferably 0.8 dl/g or greater, even more preferably 0.9 dl/g or greater, and the intrinsic viscosity is: It is usually 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 available from E.I. I. It is commercially available under the trade name Sorona® from du Pont de Nemours and Company, Wilmington, DE.

Carpets made of poly(trimethylene terephthalate) homofibers and their manufacture, and the manufacture of fibers and fibers are described in Howell et al., U.S. Patent No. 5,645,782; 015, and U.S. Patent No. 6,113,825 to Chuah; U.S. Patent No. 6,740,276; U.S. Patent No. 6,576,340; 723,799; WO 99/19557 by Scott et al.; Ｍｏｄｌｉｃｈ，“Ｅｘｐｅｒｉｅｎｃｅ ｗｉｔｈ Ｐｏｌｙｅｓｔｅｒｓ Ｆｉｂｅｒｓ ｉｎ Ｔｕｆｔｅｄ Ａｒｔｉｃｌｅｓ ｏｆ Ｈｅａｔ－Ｓｅｔ Ｙａｒｎｓ，Ｃｈｅｍｉｅｆａｓｅｒｎ／Ｔｅｘｔｉｌｉｎｄ．４１／９３，７８６－９４（１９９１）；並びにＨ．Ｃｈｕａｈ，“Ｃｏｒｔｅｒｒａ Ｐｏｌｙ（ｔｒｉｍｅｔｈｙｌｅｎｅ ｔｅｒｅｐｈｔｈａｌａｔｅ）－Ｎｅｗ Ｐｏｌｙｍｅｒｉｃ Ｆｉｂｅｒ ｆｏｒ Ｃａｒｐｅｔｓ” , The Textile Institute Tifcon '96 (1996), all of which are incorporated herein by reference Staple fibers are primarily used to prepare home carpets. BCF yarns are used to prepare all types of carpets and are generally preferred for carpets.

Typically, PTT-containing bicomponent fibers are used to make fabrics and apparel with durable stretch properties. In contrast, such stretch properties are not required for carpet manufacture. Rather, the fibers used in carpet manufacture are usually mechanically bulked to provide a high level of bulk; such fibers are commonly referred to as "BCF" fibers.

The surface fibers of the carpet are poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co-PET) first component and poly(trimethylene terephthalate) (PTT) or PTT and PET homopolymer or A second component of a blend with a PET copolymer (co-PET), in contrast to carpets made from bulk continuous homofilaments in which the surface fibers of the carpet are mechanically textured. Disclosed herein is a carpet in which the component fibers are self-lofting due to differential shrinkage.

The surface fibers of the carpet comprise a first component of poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co-PET) and poly(trimethylene terephthalate) (PTT) homopolymer or PTT and PET homopolymer. An improved process for making yarn for making carpet comprising self-lofting continuous fibers comprising a polymer or a second component of a blend with a PET copolymer (co-PET), said process comprising:
a) extruding the two components through a spinner capable of producing two or more independent melt streams;
b) combining the melt streams in a suitable spinneret to make bicomponent fibers;
c) quenching in air the self-lofting bicomponent fiber produced in step (b);
d) drawing and heat setting the self-lofting bicomponent fiber; and e) winding the self-lofting bicomponent fiber by a means suitable for subsequent processing into carpet, comprising:
A process is also disclosed in which the self-bulking bicomponent fiber comprises a step that does not require a mechanical bulking step.

The bicomponent fibers described herein may be in a side-by-side (“S/S”) arrangement or an eccentric sheath/core (“S/C”) arrangement. Bicomponent fibers are prepared by using specific spinnerets for each shape, for example as disclosed in U.S. Pat. No. 6,803,102, which is hereby incorporated by reference in its entirety. For example, it can have various cross-sectional shapes such as circular, delta, triangular, scalloped, or other shapes.

Carpet fibers are typically homofilaments that have undergone a mechanical bulking step in the manufacturing process. In contrast, carpets described herein in which the surface fibers of the carpet comprise self-lofting continuous fibers comprising bicomponent fibers comprising poly(trimethylene) terephthalate are self-lofting due to differential shrinkage.

As noted above, one component of the self-lofting bicomponent fiber is PTT or a blend of PTT and PET or co-PET. Compared to other commercially available polyesters, PTT can be very effective in providing crimps due to PTT's unique shrinkability. Another component of self-lofting bicomponent fibers is PET or co-PET, and since their shrinkage is negligible compared to PTT, this combination of components maximizes the difference in shrinkage. , crimp develops. In contrast, PBT, PTT, and PTT/PET blends shrink significantly, resulting in less shrinkage difference between the two components and less crimping in the resulting bicomponent fibers, which is less likely than poly(butylene terephthalate). ) (PBT) is a less preferred component for use with PTT or PTT/PET blends to make self-bulking bicomponent fibers. For example, at equal polymer weight ratios in a side-by-side or eccentric sheath/core self-lofting bicomponent fiber, a bicomponent fiber comprising PTT and PET as two components is a bicomponent fiber comprising PBT and PET as two components, or a different specific It will provide higher bulk than a bicomponent fiber comprising two different PETs each having a viscosity (IV) as two components.

Nylon polymers, including nylon 6 and nylon 66, are sometimes used as the first component in self-lofting bicomponent fibers, however, nylon polymers generally do not bond with polyester as the second component. Cracking and clamping may occur if the stress is not sufficient. For this reason, bicomponent fibers, including nylon and polyester, may not be the best choice for carpet yarns.

The two components, PET or co-PET and PTT or a blend of PTT and PET or co-PET, can be present in the self-bulking bicomponent fiber in weight ratios ranging from 80:20 to 20:80. For example, the weight ratios of the first component to the second component are 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60. , 35:65, 30:70, 25:75, 20:80, or any ratio within this range. In one embodiment, the weight ratio of the first component to the second component is about 50:50.

For use in carpet, the self-lofting bicomponent fiber has a crimp shrinkage value of 30% or less after heating. The crimp shrinkage rate after heating can be measured by the method for measuring the crimp shrinkage rate disclosed in the Examples section below. There are several methods by which the two components of the bicomponent fiber can be adjusted to achieve the desired post heat crimp shrinkage of 30% or less in the resulting bicomponent fiber. One option is to adjust the polymer intrinsic viscosity (IV) of each component relative to the other components. For example, if the difference in IV between the two components of a bicomponent fiber is very large, a high level of differential shrinkage can occur between the two components, resulting in high crimp values and high crimp values that are not suitable for carpet manufacture. The result is the stretch properties of the fiber. In contrast, if the IV difference between the two components is very small, there is not much difference in shrinkage between the two components, resulting in little bulk.

Another method of producing bicomponent fibers with a preferred degree of crimp is to vary the weight ratio of the two components. If the bicomponent fibers contain a significant proportion of PTT, the resulting fibers can have high crimp values and fiber stretch. Conversely, a very low amount of PTT to volume ratio may not provide sufficient post-heat bulk or crimp shrinkage to achieve the desired level.

A third method of producing bicomponent fibers with a preferred degree of crimp is to use a PET/PTT blend in a fixed ratio (e.g. 50/50 weight ratio of PTT to PET) as the first component and PET as the second component. to adopt. It has been found that blending PET and PTT in one component can be used to modify the high shrinkage properties of PTT alone. When the two components are made with a first component comprising a blend of PTT and PET and a second component that is PET, it provides the desired degree of crimp, i.e. no more than 30% crimp shrinkage after heating. (eg 50/50 w/w of Component 1:Component 2). In some spinneret designs, it may be desirable to produce bicomponent fibers with approximately equal weight ratios of the two components, and blending PET with PTT is one way to achieve this result. .

Alternatively, useful bicomponent fibers disclosed herein can be made by varying the composition of the PTT/PET blend in the first component of the bicomponent fiber, where the second component is PET or co-PET: can be made. This approach can be used to make bicomponent fibers useful where high levels of PET are desired. In summary, varying the polymer type, IV, weight ratio, and composition of the blend can all be used to design a self-lofting bicomponent fiber to achieve the desired carpet bulk with a target crimp value. It is a technology that can obtain Varying the relative speeds of the rolls and/or winders during fiber production can also affect crimp shrinkage.

One advantage of PTT in the self-lofting bicomponent fibers disclosed herein is that PTT provides a higher level of shrinkage compared to PET. Relatively small amounts of PTT can be used as the first component of self-bulking bicomponent fibers to produce bicomponent fibers with the desired bulk. However, too much PTT content in bicomponent fibers can result in levels of stretch that are too high for use in carpet yarns, making them more suitable for apparel applications.

Various additives may be added to one polymer or to both polymers. Additives include, but are not limited to, lubricants, nucleating agents, antioxidants, UV stabilizers, pigments, dyes, antistatic agents, antifouling agents, antifouling agents, antimicrobial agents, and flame retardants. .

For carpet applications, the self-lofting bicomponent fibers disclosed herein can have a denier ranging from about 300 to about 1400 grams/denier. Useful denier per filament can range from about 2 to about 20.

In one carpet embodiment, bicomponent fibers whose facing fibers comprise a first component of PET homopolymer or co-PET and a second component of PTT or a blend of PTT and PET homopolymer or co-PET. wherein the bicomponent fiber is self lofting due to differential shrinkage, the first component comprises PTT having an intrinsic viscosity ranging from about 0.9 dL/g to about 1.25 dL/g, and the second component comprises , PET having an intrinsic viscosity of about 0.64 dL/g, and a weight ratio of the two components of about 50/50.

In another embodiment, the first component comprises PTT having an intrinsic viscosity ranging from about 0.9 dL/g to about 1.0 dL/g, and the second component has an intrinsic viscosity of about 0.5 dL/g. wherein the weight ratio of the two components ranges from about 20/80 to about 30/70.

In an additional embodiment, the first component comprises a 50/50 weight/weight blend of PTT and co-PET, wherein the PTT ranges from about 0.9 dL/g to about 1.0 dL/g. wherein the co-PET has an intrinsic viscosity ranging from about 0.75 dL/g to about 0.85 dL/g, and the second component has an intrinsic viscosity of about 0.5 dL/g and the weight ratio of the two components ranges from about 70/30 to about 30/70.

In a further embodiment, the first component comprises a blend of PTT and co-PET, wherein the PTT has an intrinsic viscosity ranging from about 0.9 dL/g to about 1.0 dL/g, and the co-PET has an intrinsic viscosity in the range of about 0.75 dL/g to about 0.85 dL/g, and a weight ratio of PTT to co-PET in the blend in the range of about 10/90 to about 90/10 and the second component comprises PET having an intrinsic viscosity of about 0.5 dL/g, and the weight ratio of the two components is about 50/50.

The fibers may be produced by feeding the polymer into the spinneret in the desired volume or weight ratios. Although any conventional multicomponent spinning technique may be used, exemplary spinning apparatus and methods for making bicomponent fibers are described in US Pat. No. 5,162,074 to Hills. Are listed.

The self-lofting bicomponent fibers disclosed herein can be used in conjunction with all other types of fibers, synthetic and natural, used to make carpets. Carpets can be made by machine tufting or manual tufting, weaving and hand knotting. Examples include: 1) home and commercial wide carpets (also known as floor-to-ceiling carpets) where tufted carpets are made in long continuous lengths several meters wide; 3) household rugs; and 4) vehicle and building entrance mats designed to clean feet before entering objects.

Any method known in the art for preparing carpet from fibers can be used to prepare the carpet described herein. Generally, the self-lofting bicomponent fibers disclosed herein can be used in the same carpet manufacturing processes in which other synthetic and natural fibers are used. Bicomponent fibers may be used by themselves (i.e., as "single" yarns) in carpet construction, or may be further plied together with the same bicomponent fibers or other types of fibers (e.g., nylon, polypropylene, polyester). can be used to increase the denier. Optionally, the single and plied fibers may be entangled with an air jet prior to twisting and heat set by a machine specifically designed to heat set the physical properties of the single and tufted yarns. may be applied. An example of a heat-setting machine suitable for this purpose is manufactured by Superba® (Muhouse, France). Whether the bicomponent fibers are optionally air entangled, twisted or heat set, the fibers can then be tufted into standard nonwoven or woven backing sheets common in the carpet industry. . The face fiber loops of the tufted carpet may be cut to provide cut loop carpet. After tufting, an adhesive is often applied to the back side of the carpet (ie, opposite the face fibers) to hold the tufts in place. An additional backing layer may also be added to the back side of the carpet. The adhesive layer may contain fillers or flame retardants, depending on the particular carpet end use. The carpet may then be dyed by standard processes common in the carpet manufacturing industry; It may be added to the fibers to impart color to the finished fabric. Additionally, the face yarns may be treated with materials designed to impart fire resistance, antistatic properties, or stain and stain resistance. The finished carpet is often dried to remove any water left over from the dyeing process.

The manufacturing process described above is typical of wide tufted carpets. Variations on this process, well known in the industry, may be employed in the manufacture of rugs, tile carpets, and vehicle mats.

One of the characteristics of the bicomponent fibers disclosed herein is the development of crimp and bulk by raising the temperature of the fiber to at least 75°C but less than 200°C. During the optional heat-setting, dyeing and drying steps, the bicomponent fibers will be exposed to this temperature range during the standard course of carpet manufacture. Alternatively, the carpet can be subjected to a separate heat-setting process to raise the height, or the bicomponent fibers (single or plied yarns) can be heat-treated to raise the height.

Surface fibers, including bicomponent fibers, may be of circular or non-circular cross-section, such as trilobal. The fibers desirably have a post-heating crimp shrinkage value of 30% or less.

An advantage of the carpet disclosed herein is that the yarn used to make the carpet does not need to be mechanically bulked because the bicomponent fibers are self-bulking due to differential shrinkage. In contrast, carpet yarns made from bulk continuous homofilaments do not have differential shrinkage and therefore require mechanical bulking. That is, by using bicomponent fibers with differential shrinkage, the carpet is made without the step of mechanically bulking continuous homofilaments.

Optionally, a carpet whose surface fibers comprise the self-lofting bicomponent fibers disclosed herein may further comprise at least one additional fiber. At least one additional fiber may be twisted together with the self-lofting bicomponent fiber to increase the denier, for example, or as an additional carpet yarn in tufting carpet. may be used. The at least one additional fiber may be selected from bulked continuous filaments (ie, homofilaments), synthetic staple fibers, and natural fibers. In one embodiment, the at least one additional fiber is a bulked continuous filament, wherein the bulked continuous filament includes nylon, polypropylene, or polyester. In another embodiment, the at least one additional fiber is a synthetic staple fiber, the synthetic staple fiber comprising nylon or polyester. In further embodiments, the at least one additional fiber is a natural fiber, the natural fiber including wool, silk, or cotton.

Non-limiting examples of embodiments disclosed herein include:
1. The surface fibers comprise a first component of poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co-PET) and poly(trimethylene) terephthalate (PTT) or poly(trimethylene terephthalate) (PTT). ) and a second component of a blend of poly(ethylene terephthalate) (PET) homopolymer or poly(ethylene terephthalate) copolymer (co-PET), the surface fibers of which are mechanical Carpets in which the bicomponent fibers are self-bulking due to differential shrinkage, in contrast to carpets made from bulk continuous homofilaments that have been bulked.
2. 2. The carpet of embodiment 1, wherein the bicomponent fibers may be in a side-by-side arrangement or an eccentric sheath/core arrangement.
3. 3. The carpet of embodiment 1 or 2, wherein the first and second components of bicomponent fibers are present in a weight ratio ranging from 80:20 to 20:80.
4. 4. The carpet of embodiment 1, 2 or 3, wherein the bicomponent fiber has a crimp shrinkage after heating of 30% or less as determined according to the crimp shrinkage method.
5. 5. The carpet of embodiment 1, 2, 3 or 4, wherein the surface fibers further comprise at least one additional fiber selected from bulked continuous filaments, synthetic staple fibers, and natural fibers.
6. 6. The carpet of embodiment 5, wherein the at least one additional fiber is a bulked continuous filament, the bulked continuous filament comprising nylon, polypropylene, or polyester.
7. 6. The carpet of embodiment 5, wherein the at least one additional fiber is a synthetic staple fiber, the synthetic staple fiber comprising nylon or polyester.
8. 6. The carpet of embodiment 5, wherein the at least one additional fiber is a natural fiber, the natural fiber comprising wool, silk, or cotton.
9. An improved process for making yarn for making carpet, wherein the surface fibers of the carpet are a first component of poly(ethylene terephthalate) homopolymer or poly(ethylene terephthalate) copolymer and poly(trimethylene terephthalate). or a self-lofting bicomponent fiber comprising poly(trimethylene terephthalate) and a second component of a blend of poly(ethylene terephthalate) homopolymer or poly(ethylene terephthalate) copolymer, wherein said process:
a) extruding the two components through a spinner capable of producing two or more independent melt streams;
b) combining the melt streams in a suitable spinneret to make bicomponent fibers;
c) quenching in air the self-lofting bicomponent fiber produced in step (b);
d) drawing and heat setting the self-lofting bicomponent fiber; and e) winding the self-lofting bicomponent fiber by a means suitable for subsequent processing into carpet, comprising:
An improved process wherein the self bulking bicomponent fiber does not require a mechanical bulking step.
10. The improved process of Example 9, wherein the bicomponent fiber may be in a side-by-side arrangement or an eccentric sheath/core arrangement.
11. 11. The improved process of embodiment 9 or 10, wherein the first and second components of the bicomponent fiber are present in a weight ratio ranging from 80:20 to 20:80.
12. 12. The improved process of embodiment 9, 10, or 11, wherein the crimp shrinkage after heating of the bicomponent fiber is 30% or less as determined according to the crimp shrinkage method.

The disclosure is further defined in the following examples. It should be understood that the Examples, while indicating specific embodiments, are provided by way of illustration only. From the above discussion and examples, one skilled in the art can ascertain the essential features of this disclosure, and make various modifications to suit various uses and conditions without departing from the spirit and scope of the invention. Forms and modifications may be made.

As used herein, "Comp. Ex." means comparative example, "Ex." means example, "No." means number; , means percent or percentage, “wt%” means percent by weight, “IV” means intrinsic viscosity, “dL/g” is deciliters/gram, “g” is grams where "mg" is milligram, "°C" means degrees Celsius, "°F" means degrees Fahrenheit, "temp" means temperature, and "min" means "h" is hour, "sec" is second, "lb" is pound, "kg" is kilogram, "mm" is millimeter, "m ' is meter, 'gpl' is gram/liter, 'm/min' is meter/minute, 'mol' is mole, 'kg' is kilogram, and ' ppm" is parts/million, "wt" is weight, "dpf" is denier/filament, "gpd" or "g/d" is grams/denier, "dtex ' means decitex, 'dN/tex' means 'decinewton/tex, 'mL' means milliliter, and 'IV' means intrinsic viscosity.

All materials were used as received unless otherwise stated.

Measurement of Crimp Shrinkage (%CCa) after Heating by Crimp Shrinkage Method The value of crimp shrinkage (Cca) after heating was determined according to the method described herein. Each example and comparative fiber was independently formed into a skein of about 5000+/-5 total denier (5550 dtex) using a skein reel with a tension of about 0.1 gpd (0.09 dN/tex). The skein was then folded in half to fit the interior of the oven used for heat setting. The middle portion of the folded skein was hooked and conditioned at 70+/-1°F (21+/-1°C) and 65+/-2% relative humidity for a minimum of 16 hours. The folded skein was then hung from the hook in the middle of the skein approximately vertically on a rack, and a 1.5 mg/den (1.35 mg/dtex) weight was hung at the bottom of the skein through the two loops of the folded skein. rice field. 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, allowed to cool for 5 minutes, and then weighed at 1.5 mg/denier weight for the remainder of the test. were left in skeins and conditioned at 70°F +/- 1°F (21 +/- 1°C) and 65% +/- 2% relative humidity for a minimum of 2 hours. The length of the skein was measured to the nearest 1 mm and recorded as "Ca". A 1000 g weight was then suspended at the bottom of the skein to allow equilibrium and the length of the skein was measured to the nearest 1 mm and recorded as "La". The crimp shrinkage rate "CCa" value (%) after heating was calculated by the following formula:
%CCa = 100 x (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 gram sample was weighed into a 40 mL glass vial containing 30 mL of solvent (phenol/1,1,2,2-tetrachloroethane (60/40 wt %)) and a stir bar. The samples were then placed in a heat block preheated to 100° C., heated and stirred for 30 minutes, removed from the block and allowed to cool for 30-45 minutes before being placed in the viscometer autosampler rack. The samples were then analyzed by ASTM method D5225-92, a standard test method for measuring solution viscosity of polymers using a differential viscometer.

Polymer Preparation Two grades of PTT homopolymer pellets were prepared by E.I. It was obtained from I du Pont de Nemours and Company, Wilmington, Delaware USA. One grade had an IV of 1.02 dL/g and a second grade had an IV of 0.96 dL/g. PET homopolymer pellets are available from Sinopec Shanghai Petrochemical Company, Ltd. It was obtained from Shanghai, PRC and had an IV of 0.50 dl/g. PET homopolymer pellets were obtained from DuPont Crystar® and had an IV of 0.64 dl/g. Co-PET copolymer (containing 1.9 mol % isophthalic acid) pellets with an IV of 0.82 dl/g were obtained from NanYa Plastics Corporation, Livingston New Jersey, USA.

A polymer blend composition was made from a physical blend of 0.96 IV PTT pellets and 0.82 IV PET copolymer pellets (“sesame and salt” (S&P) blend) prior to extrusion. The extrusion process during spinning intimately mixed these pellet blends. Alternatively, in some examples, PTT pellets and PET copolymer pellets were compounded in a twin-screw extruder, pelletized and used directly during spinning without the need to create a salt-and-sesame blend.

In preparation for melt spinning, the pellets were dried in a vacuum oven under nitrogen at 25 inches of mercury vacuum and a temperature of 120° C. for 15 hours. The dried pellets were transferred directly to the nitrogen purged feed hopper of the spinner.

Fiber Preparation Processes and apparatus generally applicable to spinning the two components of a bicomponent fiber into side-by-side and eccentric sheath/core bicomponent fibers, such as US Patents, which are incorporated herein by reference. It was melt spun using the process and equipment disclosed in US Pat. No. 6,641,916 B1, US Pat. No. 6,803,102, and US Pat.

In spinning the bicomponent fibers of the examples, the polymer was melted in a pair of Werner & Pfleiderer 28-mm co-rotating twin screw extruders with capacities of 0.5 to 40 pounds per hour (0.23 to 18.1 kg per hour). bottom. One extruder, herein referred to as the East extruder, is used to melt PET homopolymer (IV 0.50 and 0.64) pellets and a second extruder, herein referred to as the West extruder, is used to 1) PTT pellets alone, 2) sesame and salt-like (“S&P”) blends of PTT pellets and co-PET copolymer pellets, or 3) blended PTT/co-PET pellets were melted. The West extruder, spin block and East extruder temperatures are listed in the examples. Each extruder fed a spin block containing a concave spinneret. The spinneret used had 34 pairs of capillaries arranged in a circle, an internal angle of 30 degrees between each pair of capillaries, a capillary diameter of 0.64 mm, and a capillary length of 4.24 mm. coalescence) side-by-side bicomponent spinneret.

The bicomponent filaments exiting the spinneret were cooled by a cross flow of quench air at a nominal 20°C and a face velocity of 0.5 mm/sec. The filament was then advanced to dual feed rolls operating at about 800-1200 meters/minute, depending on draw ratio. A finish applicator was used to apply lubricant to the filament bundles between the spinneret and the feed roll. The feed rolls were typically heated to 70° C. to affect stretching. The filament bundle was then accelerated to an annealing roll operating at a speed of about 3000-3600 m/min, depending on the desired draw ratio, and the temperature of the annealing roll was typically 170°C. The annealed bicomponent fiber was then run through two sets of dual letdown rolls operating at room temperature before winding on a Barmag SW6 600 winder. The fibers had a snowball (rectangular) cross-sectional shape.

Example 1
Variations in PTT Intrinsic Viscosity (IV) Example 1 illustrates the use of PTT pellets with different IVs to produce bicomponent fibers with desired values of crimp shrinkage (CCa) after heating. . The IV of the PTT pellets used to make the fibers was either 1.25 dl/g (1a) or 1.02 dl/g (1b). The IV of the PET pellets was 0.64 dl/g in both cases. In each example, the weight ratio of PTT to PET was 50/50. Example 1-a was a 115 denier 34 filament fiber. Example 1-b was a 75 denier, 34 filament fiber.

Example 2
PTT/PET Weight Ratio Variation Example 2 illustrates how changing the weight ratio of the PTT and PET components in the bicomponent fiber changes the crimp shrinkage (CCa) after heating. The bicomponent fiber was 75 denier with 34 filaments. In Table 2, Comparative Examples A, B, and C exhibit high levels of CCa, ie greater than 30%, and are more suitable for apparel products requiring stretch and recovery. Examples 2a, 2b, and 2c illustrate process conditions that result in lofty bicomponent fibers having a crimp shrinkage of 30% or less after heating that are suitable for making carpet. The winder speed was 3495 m/min for Comparative Example A and 3500 m/min for Comparative Examples B and C and Examples 2a, 2b and 2c.

Example 3
Variation in weight ratios between the two components when using a constant PTT/co-PET blend as the first component. An example is shown in which the second component is made from PET. In Examples 3a-e, 0.96 dl/g IV PTT pellets and 0.82 dl/g IV co-PET pellets of a 50/50 weight percent "sesame and salt" blend are randomly dispersed together. mixed up to After drying, the pellet mixture was fed into the West extruder. Dried PET homopolymer pellets with an IV of 0.50 were fed into the East extruder. Bicomponent fibers were then made in which the first component contained the 50/50 weight ratio PTT/co-PET blend described above and the second component was PET, with varying weight ratios between the two components. For example, Example 3a was made with a 70/30 weight ratio between the first component (ie, a 50/50 PTT/co-PET blend) and the second component (ie, PET). For the remaining examples in Table 3, the polymer remained the same and the weight ratio between the two components varied. The winder speed was 3500 m/min for all these examples.

Example 4
Variations in the PTT/co-PET blend ratio in the first component when the weight ratio between the two components is fixed An example in which the component is made from PET is shown. In contrast to Table 3, the examples shown in Table 4 show the effect of varying the blend ratio of PTT to co-PET in the first component while maintaining a constant 50/50 weight ratio between the two components. In Table 4, Examples 4a-4d and 4f-4g, as well as Comparative Example D, are shown in the "Sesame Salt Blend"("S&P") of PTT with an IV of 0.96 dl/g and co-PET with an IV of 0.82 dl/g. It was produced by changing the pellet ratio. The pellets were mixed together until randomly dispersed. After drying, the pellet mixture was fed into the West extruder. Dried PET homopolymer pellets with an IV of 0.50 were fed into the East extruder. Then, the first component comprises the PTT/co-PET blend described above, the second member consists of PET, and the weight ratio between the two members is fixed at 50/50. A bicomponent fiber was made with For example, in Example 4a, the first of the two components was made from PTT/co-PET in a 10/90 blend ratio and the second of the two components was made from PET. The weight ratio between the two components was 50/50. In Example 4-e, PTT and co-PET pellets were precompounded in a twin screw extruder, quenched, pelletized and dried again before use. This is in contrast to Example 4d, where the ingredients were made from a sesame salt blend. It should also be noted that Comparative Example D has a higher crimp shrinkage value after heating, %CCa=43.1, which is more suitable for apparel fabrics with high levels of stretch.

For Example 4-a the winder speed was 3475 m/min and for Examples 4-b, 4-c, 4-d, 4-e, 4-f, 4-g and Comparative Example D , the winder speed was 3500 m/min.

実施例５
実施例２ａのような自己嵩高型二成分繊維を用いるカーペットの製造
自己嵩高型二成分繊維を含むカーペットを、上述の実施例２ａに記載したポリマー、ポリマーのＩＶ、及び繊維重量比を用いて、１２００デニール－１２０フィラメント（１０ｄｐｆ）で紡糸することができる。これらの二成分繊維は、実施例２ａでの繊維よりも大きいデニール及びフィラメント数を有することとなる。得られる繊維が、３０％以下の加熱後の捲縮収縮率を有するように、紡糸速度（即ち、延伸比）を調節することとなる。次に、このように作製した二成分繊維を同種類の第二の二成分繊維と標準の撚糸装置で撚り合わせることができる。二成分繊維の捲縮を十分に発現させて撚糸の撚りを設定する、Ｓｕｐｅｒｂａ（登録商標）ヒートセット装置により、撚糸後、繊維を処理できる。次に、ヒートセット二成分糸を、標準のカーペットのタフティングマシンで、同じ組成の他のヒートセット糸と一緒にポリプロピレン不織布の裏地にタフティングして、ヒートセットした二成分の合撚り糸のみからなるタフティング布を得ることができる。次に、タフトした布帛をカーペット業界で使用される標準的な加工装置で加工して、カーペットの裏にラテックス製剤を塗布し、タフトした表面繊維をカーペット織物の裏面に固着することができる。その後、２次裏打ちを施し、カーペットの下面を保護する。次に、生機（未乾燥）のカーペットを標準の連続染色装置で処理した後、連続オーブン中で乾燥させて、水分を除去することができる。その後、完成したカーペットを現地で設置するために、大きなチューブに巻き取る。

Example 5
Manufacture of carpet using self-lofted bicomponent fibers as in Example 2a Carpets containing self-lofted bicomponent fibers were prepared using the polymers, polymer IVs, and fiber weight ratios described in Example 2a above. It can be spun at 1200 denier-120 filament (10 dpf). These bicomponent fibers will have a higher denier and filament count than the fibers in Example 2a. The spinning speed (ie draw ratio) will be adjusted so that the resulting fiber has a post-heating crimp shrinkage of 30% or less. The bicomponent fiber so produced can then be twisted with a second bicomponent fiber of the same type on standard twisting equipment. After twisting, the fibers can be treated with Superba® heat-setting equipment, which fully develops the crimp of the bicomponent fibers and sets the twist of the twisted yarn. The heat-set bicomponent yarn is then tufted on a standard carpet tufting machine, along with other heat-set yarns of the same composition, onto a polypropylene nonwoven backing to produce a plied yarn from only the heat-set bicomponent ply yarn. A tufting cloth can be obtained. The tufted fabric can then be processed on standard processing equipment used in the carpet industry to apply a latex formulation to the back of the carpet and bond the tufted face fibers to the back of the carpet fabric. A secondary backing is then applied to protect the underside of the carpet. The greige (undried) carpet can then be treated in standard continuous dyeing equipment and then dried in a continuous oven to remove moisture. The finished carpet is then rolled into a large tube for on-site installation.

Example 6
Carpet product using self-lofting bicomponent fibers as in Example 2a but having a trilobal cross-sectional shape. and fiber weight ratio can be used to spin at 1200 denier-120 filament (10 dpf). The spinneret orifices are chosen to produce a side-by-side trilobal cross-sectional shape, although any other cross-sectional shape useful in carpet manufacturing can be selected. These bicomponent fibers will have a higher denier and filament count than in Example 2a and the trilobal cross-sectional shape. The spinning speed (ie draw ratio) will be adjusted so that the resulting fiber has a post-heating crimp shrinkage of 30% or less. The bicomponent fiber so produced can then be twisted with a second bicomponent fiber of the same type on standard twisting equipment. After twisting, the fibers can be treated with Superba® heat-setting equipment, which fully develops the crimp of the bicomponent fibers and sets the twist of the twisted yarn. The heat-set bicomponent yarn is then tufted on a standard carpet tufting machine, along with other heat-set yarns of the same composition, onto a polypropylene nonwoven backing to produce a plied yarn from only the heat-set bicomponent ply yarn. A tufting cloth can be obtained. The tufted fabric can then be processed on standard processing equipment used in the carpet industry to apply a latex formulation to the back of the carpet and bond the tufted face fibers to the back of the carpet fabric. A secondary backing is then applied to protect the underside of the carpet. The greige (undried) carpet can then be treated in standard continuous dyeing equipment and then dried in a continuous oven to remove moisture. The finished carpet is then rolled into a large tube for on-site installation.

Claims (14)

A carpet, the surface fibers of which comprise a first component of poly(ethylene terephthalate) homopolymer or poly(ethylene terephthalate) copolymer and poly(trimethylene) terephthalate or poly(trimethylene terephthalate) and poly(ethylene terephthalate) homopolymer or a second component of a blend with a poly(ethylene terephthalate) copolymer, the surface fibers of which are made from bulk continuous homofilaments that have been mechanically textured, in contrast to carpets made from said two components. A carpet in which the component fibers are self-bulking due to differential shrinkage. 2. The carpet of claim 1, wherein said bicomponent fibers may be in a side-by-side arrangement or an eccentric sheath/core arrangement. 3. Carpet according to claim 1 or 2, wherein the first and second components of said bicomponent fibers are present in a weight ratio ranging from 80:20 to 20:80. 3. The carpet of claim 1 or 2, wherein the bicomponent fiber has a crimp shrinkage after heating of 30% or less when determined according to the crimp shrinkage method. 4. The carpet of claim 3, wherein said bicomponent fiber has a crimp shrinkage after heating of 30% or less when determined according to said crimp shrinkage method. 2. The carpet of claim 1, wherein said surface fibers further comprise at least one additional fiber selected from bulked continuous filaments, synthetic staple fibers, and natural fibers. 7. The carpet of claim 6, wherein said at least one additional fiber is a bulked continuous filament, said bulked continuous filament comprising nylon, polypropylene, or polyester. 7. The carpet of Claim 6, wherein said at least one additional fiber is a synthetic staple fiber, said synthetic staple fiber comprising nylon or polyester. 7. The carpet of claim 6, wherein said at least one additional fiber is a natural fiber, said natural fiber comprising wool, silk or cotton. An improved process for making yarn for making carpet, wherein the face fibers of the carpet are a first component of poly(ethylene terephthalate) homopolymer or poly(ethylene terephthalate) copolymer and poly(trimethylene terephthalate). ) or a self-lofting bicomponent fiber comprising poly(trimethylene terephthalate) and a second component of a blend of poly(ethylene terephthalate) homopolymer or poly(ethylene terephthalate) copolymer,
said method comprising:
a) extruding the two components through a spinner capable of producing two or more independent melt streams;
b) combining said melt streams in a spinneret suitable for making bicomponent fibers;
c) quenching in air the self-lofting bicomponent fiber produced in step (b);
d) drawing and heat setting the self-lofting bicomponent fiber; and e) winding the self-lofting bicomponent fiber by a means suitable for subsequent processing into carpet, comprising:
A method wherein the self bulking bicomponent fiber does not require mechanical bulking. 11. The method of claim 10, wherein the bicomponent fibers may be in a side-by-side or eccentric sheath/core arrangement. 12. A method according to claim 10 or 11, wherein said first and second components of said bicomponent fiber are present in a weight ratio ranging from 80:20 to 20:80. 12. The method of claim 10 or 11, wherein the crimp shrinkage of the bicomponent fiber after heating is 30% or less when determined according to the crimp shrinkage method. 13. The method of claim 12, wherein the crimp shrinkage of the bicomponent fiber after heating is 30% or less as determined according to the crimp shrinkage method.