Two-component yarn with improved bulk and feel, and elastic fabric containing the two-component yarn.

Abstract

The present invention includes fabrics and yarns comprising a two-component polyester multifilament yarn. The two-component polyester yarn is made from polyethylene terephthalate and polytrimethylene terephthalate in a parallel or eccentric sheath core configuration. Compared to conventional two-component polyester yarns, this yarn has improved bulk and provides a more desirable feel in fabrics.

Description

Technical Field

[0001] The present invention includes a fabric containing a polyester bicomponent multifilament yarn and a yarn. This yarn has improved bulk compared to conventional bicomponent yarns and provides a more desirable feel in the fabric.

[0002] Summary of Related Art From polyethylene terephthalate and polytrimethylene terephthalate, bicomponent polyester yarns (or any fiber that meets the FTC definition of elastelene p) made in a parallel or eccentric sheath-core configuration have, as a distinguishable characteristic, a coil structure (also known as helical crimp) resulting from the difference in shrinkage of the two components of the parallel fibers. Polyethylene terephthalate or polytrimethylene terephthalate are present in separate domains within the fiber in a parallel configuration along the length of the fiber, and each shrinks to a different extent, and when this occurs, the fiber is made into a coil structure.

[0003] In the case of fabric applications, the bicomponent fibers are sold as a bundle of multifilaments called "yarn" (for example, commercially available from The LYCRA Company as LYCRA® T400® fiber). This yarn is composed of a plurality of filaments each in the range of 0.9 to 3.0 denier per filament. A typical yarn has a total denier of 50 composed of 34 filaments. Other examples include 70 denier - 68 filaments, 150 denier - 72 filaments, etc. Any total yarn denier is possible by combining multiples of the individual 0.9 to 3.0 denier filaments.

[0004] A common consumer complaint regarding fabrics made using this fiber is that they have a rough texture. This is thought to be due to the fiber's high shrinkage and coiled nature, which is an inherent characteristic of the fiber recognized in the U.S. Federal Trade Commission (FTC) definition of elasterel p. The FTC defines "elasterel p" as a fiber formed by the interaction of two or more chemically specific polymers (not exceeding 85% by weight) containing an ester group as the dominant functional unit (at least 85% by weight of the fiber's total polymer content). When stretched to at least 100%, it substantially returns to its unstretched length sustainably and rapidly when the tension is removed.

[0005] By applying any process that shrinks the fibers (which may include placing them in water above 40°C, applying steam, or using dry heat above 60°C), all the individual filaments shrink and become a tightly packed multifilament coil. This multifilament coil no longer exhibits the advantages of being composed of individual 0.9-3.0 denier filaments, but rather has a much higher denier feel, which is the result of the combined denier of the individual filaments. It is well recognized among industry and consumers that longer (lower denier) yarns have a more desirable feel, and therefore, in elastomer fabrics, this tightly packed multifilament coil results in an undesirable feel compared to similar yarn denier made from homofiber filaments. [Overview of the project]

[0006] To improve the feel of fabrics containing two-component polyesters, such as elastomerel p, also known as elastomultiester, the applicant has attempted to break the coils of yarn formed by the inherent crimp in the filament structure. This has been overcome by the development of novel two-component multifilament yarns that reduce the ability of the yarn to shrink into a tightly packed multifilament bundle. Reducing the ability to shrink into a tightly packed bundle within the yarn is possible by producing yarns from filaments having different filament deniers, filaments having elliptical cross-sections, filaments with mixed cross-sections, filaments with mixed polymer ratios, or filaments having sufficiently low crimp potential (CP) combined with low crimp shrinkage (CS) that reduces the tendency of the filaments to pack tightly. Each of these alternative forms can be combined to provide different properties to the yarn.

[0007] Regarding the above examples of different filament deniers, in the case of an existing 50-denier yarn composed of 34 filaments, it contains 34 individual filaments, each of which is (50 / 34 = 1.47 denier). This means that all 34 filaments, when exposed to conditions that lead to shrinkage, have the same properties and the potential to form the same degree of helical crimp. Surprisingly, the inventors found that by using a spinneret for fiber spinning, it is possible to produce these 34 filaments in a range of denier (e.g., a 50-denier yarn composed of 12 filaments of 1.3 denier, 12 filaments of 1.5 denier, and 10 filaments of 1.7 denier). This variation in denier leads to variation in polymer orientation within the fiber, which in turn leads to variation in the degree of helical crimp formation within the yarn, thereby providing the yarn bundle with enough variation to disrupt the structure of the multifilament coil. As a result, the individual fibers are loosened, so when the consumer touches it, an effective low denier is given to the feel of the hand. The present invention includes a fiber, a process for producing the fiber using multiple sizes of pores within the spinaret, and a fiber spinning process that yields a yarn in which the helical crimp continues to develop sufficiently to deliver elastic properties to the fabric, which is recognized as being unique to elasterel p. [Brief explanation of the drawing]

[0008] [Figure 1] These are images of the right sides of both fabrics of the circular knitted fabric of Example 1A. [Figure 2] These are images of the reverse side of both fabrics of the circular knitted textile in Example 1A. [Figure 3] Examples 1 are images of the right sides of both fabrics of a circular knitted fabric made of AC fibers. [Figure 4] Example 1 shows images of the reverse side of both fabrics of a circular knitted fabric made of AC fibers. [Modes for carrying out the invention]

[0009] The fabrics described herein include polyester bicomponent fabrics and may include other fibers. Polyester bicomponent filaments are made into yarn from filaments having one or more of the following: different filament deniers, filaments with elliptical cross-sections, filaments with mixed cross-sections, filaments with mixed polymer ratios, or filaments having sufficiently low crimp potential (CP) combined with low crimp shrinkage (CS) which reduces the tendency of the filaments to pack tightly. Each of these alternative forms can be combined to provide different properties to the yarn.

[0010] In one aspect of the present invention, a two-component multifilament yarn is provided, having at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament are independently selected and differ in at least one of (a) denier per filament, (b) the ratio of the first component to the second component of the filament, (c) the cross-section, and (d) the method of combining them.

[0011] In another aspect of the present invention, there is an elastic fabric comprising a two-component multifilament yarn having at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament are independently selected and at least one of the following differs: (a) denier per filament, (b) ratio of the first component of the filament to the second component of the filament, (c) cross-section, and (d) method of combining them.

[0012] In another aspect of the present invention, the elastic fabric further comprises a second yarn. The second yarn may be selected from materials including cotton, polyester, polyurethane, polyolefin, polyamide, and combinations thereof.

[0013] In one aspect of the present invention, the elastic fabric may include knitted or woven elastic fabrics.

[0014] In one preferred embodiment of the present invention, the first and second components of the aforementioned two-component yarn may include polyester selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate.

[0015] In another aspect of the present invention, the denier per filament (dpf) in the two-component multifilament yarn may be about 20 to about 150 dpf. Preferably, the dpf may be in the range of about 30 to about 100, about 40 to about 90, about 50 to about 80, and about 60 to about 75.

[0016] In another aspect of the present invention, the DPF range of the two-component multifilament yarn may be about 0.8 to about 4.0, 1.0 to about 3.0, 1.5 to about 2.5, and 2 to about 4. In one preferred aspect of the present invention, the DPF range of the two-component multifilament yarn may be about 1.0 to about 3.5.

[0017] In another aspect of the present invention, the ratio of the first component to the second component may be about 30:70 to about 70:30.

[0018] In another aspect of the present invention, the cross-section of the filament has an aspect ratio of 1.5:1 or greater. In another aspect of the present invention, the cross-sectional shape of the filament may be circular, elliptical, snowman-shaped, or ribbon-shaped.

[0019] In another aspect of the present invention, the crimp shrinkage (CS) may be about 0.5% to about 10%, calculated as described herein. Preferably, the crimp shrinkage may be about 2% to about 8%, about 4% to about 10%, about 4% to about 8%, and about 5% to about 10%.

[0020] In another aspect of the present invention, the crimping potential may be about 40% to about 70%, about 45% to about 65%, and 55% to about 70%.

[0021] In yet another aspect of the present invention, a method is provided for preparing a two-component multifilament yarn comprising at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament differ in (a) denier per filament, (b) ratio of the first component to the second component of the filament, (c) cross-section, and (d) at least one combination thereof, and the method comprises the step of extruding a polymer comprising the first component and the second component for each filament through separate holes of a spinaret, wherein (a) the holes differ in size, (b) the holes differ in cross-section, (c) within each of the holes thereof the ratio of the first component to the second component as described above, and (d) one or more combinations of (a) to (c).

[0022] In yet another aspect of the present invention, a method is provided for preparing a two-component multifilament yarn, wherein a first two-component filament is prepared by selecting one or more of the properties of (a), (b), or (c) above, and a second two-component filament is prepared by selecting one or more of the properties of (a), (b), or (c) which are the same as or different from those of the first two-component filament, and both the first and second are combined into a single multifilament yarn by an entanglement, twisting, or air-jet yarn processing process. In one aspect of the present invention, the properties selected between the first two-component multifilament yarn and the second two-component multifilament yarn may not be completely but partially overlapping. In another aspect of the present invention, the properties selected between the first two-component multifilament yarn and the second two-component multifilament yarn may be completely overlapping.

[0023] In a particularly useful embodiment of the present invention, the bicomponent multifilament yarn may comprise poly(ethylene terephthalate) ("PET") and poly(trimethylene terephthalate) ("PTT"), and the bicomponent filaments may have a substantially elliptical cross-sectional shape with an aspect ratio A:B of from about 2:1 to about 5:1, where A is the major axis length of the fiber cross-section and B is the minor axis length of the fiber cross-section, the yarn may have a polymer interface substantially perpendicular to the major axis, and the yarn may comprise a cross-sectional configuration selected from a并列 and eccentric sheath-core configuration.

[0024] In one particularly useful embodiment of the present invention, an elastic fabric is provided that comprises a bicomponent multifilament yarn comprising 2GT / 3GT, and the crimp potential can be from about 40% to about 70%, and the crimp shrinkage can be from about 0.5% to about 8%. In another particularly useful embodiment of the present invention, an elastic fabric is provided that comprises a bicomponent multifilament yarn comprising 2GT / 3GT, and the crimp potential can be less than about 60%, and the crimp shrinkage can be from about 0.5% to about 6%.

[0025] Bicomponent filaments having different crimp characteristics may be simultaneously extruded from a spinneret containing holes of different sizes or shapes and then combined to form the multifilament bicomponent yarns described herein.

[0026] Alternatively, the bicomponent filaments may be prepared, extruded through separate spinnerets, and then combined into a single multifilament bicomponent yarn containing different filaments. The filaments may be combined by any known process such as twisting or air jet interlacing.

[0027] The bicomponent filaments herein may be of any of a variety of different cross-sections. This may include, among other things, circular, elliptical, ribbon, scalloped elliptical, keyhole, and snowman shapes.

[0028] The bicomponent filaments of different cross-sections may be ribbon-like as disclosed in U.S. Patent No. 7,195,819, which is hereby incorporated by reference in its entirety.

[0029] As used herein, “two-component fiber” means a short fiber in which two polymers of the same general class are in a parallel or eccentric sheath-core relationship or configuration.

[0030] As used herein, the term “parallel” means that the two components of a two-component fiber are immediately adjacent to each other, and that a small portion of one component lies within a concave portion of the other. “Eccentric sheath core” means that one of the two components completely surrounds the other, but the two components are not coaxial.

[0031] As used herein, “substantially elliptical” means that the area of ​​the fiber cross-section measured perpendicular to the longitudinal axis of the fiber deviates by less than approximately 20% from the area of ​​the elliptical shape. The general term “elliptical” includes both “oval” and “elliptical” in its meaning. Such shapes typically have two axes perpendicular to each other through the center of the shape, namely the principal axis (A) and the minor axis (B), where the length of the principal axis A is longer than the length of the minor axis B. In the special case of a perfect ellipse, the ellipse is described by the locus of points where the sum of the distances from the two foci is constant and equal to A. In the more general case of an oval, one end of the ellipse is therefore where the sum of the distances from the two foci is not necessarily constant and can vary by more than 20% from the ellipse.

[0032] As used herein, the "approximately elliptical" cross-sectional periphery may or may not have a certain curvature.

[0033] The "aspect ratio" is the ratio of the length of the principal axis (A) of an ellipse to the length of the minor axis (B) of the ellipse; in other words, it means A:B.

[0034] A "polymer interface" refers to the boundary where polymer threads used in a material meet, for example, the boundary between poly(ethylene terephthalate) and poly(trimethylene terephthalate). Polymer interfaces can be substantially linear or curved.

[0035] "Close kneading" refers to the process of thoroughly mixing dissimilar fibers by weight in an open chamber (e.g., having a weighing pan hopper feeder) before supplying the mixture to the card, or the process of mixing fibers in a dual feed chute on the card. "Draw frame blending" refers to the process of blending carded two-component fiber slivers with one or more other carded fiber slivers while the slivers are being stretched on a draw frame.

[0036] The fibers of the present invention preferably have a substantially elliptical cross-sectional shape with an aspect ratio A:B of about 2:1 to about 5:1 (including, for example, about 2.6:1 to about 3.9:1 and 3.1:1 to about 3.9:1). If the aspect ratio is too high or too low, the fibers may exhibit undesirable luster and low dye yield, and the spinning containing the fibers may not be sufficiently uniform. The fibers also have a polymer interface substantially perpendicular to the principal axis of the cross-section and a free fiber length retention rate of about 40% to about 85%. Such elliptical filaments can be spun from spinneret orifices such as slot-shaped (flat or with side bulges), elliptical, etc.

[0037] Elliptic cross-sectional shapes substantially do not contain grooves around the periphery of the cross-section; that is, when the length of the minor axis is plotted against the length of the principal axis, there is only one maximum value. Examples of cross-sectional shapes with grooves are the "snowman," "scallop-shaped ellipse," and "keyhole" cross-sections.

[0038] The two-component filaments may also include different polymer ratios, as shown in U.S. Patent No. 20060008644, which is incorporated herein by reference as a whole.

[0039] Multiple fibers, each having a different ratio of distinct polymers, may be produced using a single spinneret by varying the ratio of polymers supplied to each opening of the spinneret, such as by using the method described in U.S. Patent No. 3,671,379 by Evans et al. In this case, these fibers can be wound into a yarn of two-component fibers of the mixed ratio without the need to wind other yarns separately to form a larger yarn. Various two-component fibers with mixed component ratios, or yarns of these fibers, can be combined to form single yarns that can be used to knit fabrics.

[0040] The weight ratio of the individual two-component fibers of the yarn of the present invention may be any weight ratio of one component to the other, but typically the ratio may be between about 75 / 25 and 25 / 75, and more typically between about 70 / 30 and 30 / 70.

[0041] Regardless of the weight ratio of individual fibers, the overall weight ratio or net weight ratio of components in the yarn may be about 45 / 55 to about 75 / 25, where the first number represents the component having smaller mass repeating units. Preferably, the overall net weight ratio may be asymmetrical; for example, in a preferred embodiment of the present invention using PET and PTT as components, a higher amount of the component having smaller repeating units, i.e., PET, is preferred.

[0042] The weight ratio of one component to the other may vary between fibers within the yarn, thus creating a two-component fiber with a specific mixing ratio. The components of various filaments can typically differ by more than about 10 weight percent in a given yarn. For example, a yarn may typically contain several two-component fibers of 30 / 70, 40 / 60, 50 / 50, 60 / 40, and 70 / 30, but not typically 30 / 70, 33 / 67, 50 / 50, 67 / 33, and 70 / 30. Differences of less than about 10 weight percent do not allow for the creation of two-component fibers with a crimp difference sufficient to achieve the most desired level of avoiding crimp that follows the leader.

[0043] Once the yarn is spun, it can be used to knit fabrics that have desirable properties such as smoothness and a silky touch.

[0044] Another suitable two-component filament may contain about 40 to about 70 CP and have a CS of less than about 8. For example, a useful two-component filament may have about 40 to about 60 CP, 50 to about 65 CP, and about 1 to 6 CS. Methods for preparing such fibers are well known and are described in U.S. Patent No. 6,868,662, which is incorporated herein by reference in whole.

[0045] Crimp potential ("CP") and crimp shrinkage ("CS") were determined by measuring the length of the yarn skein under standard load before and after dry heat treatment. A 7000 denier (7778 dtex) (measured at double the value), 1 / 2-inch wide skein sample was prepared from the yarn to be tested. The skein sample was mounted on a Texturemat-ME (Lawson Hempphil Sales Co.) carrier and a load of 700 g (100 mg / d) was applied for at least 10 seconds. The skein length was determined and reported as L1. The sample was removed from the machine and placed in a hot air oven (Lawson Hempphil Sales Co.) and held at 121.0 ± 0.2 °C for 5 minutes. It was then removed from the oven and allowed to cool for 20 minutes. The sample was returned to the Texturemat-ME, a load of 10.5 g (1.5 mg / d) was applied, and the skein length was recorded as L2. Finally, a load of 700g was applied again to determine the length of the skein, which was recorded as L3. %CP and %CS were calculated using the following formulas.

number

[0046] All samples in the examples had a crimp shrinkage of 7-9%. Since crimp shrinkage % (CC%) is calculated as 100 × (L3 - L2) / L3, the crimp potential is related to the crimp shrinkage according to the following formula. CP = CC × L3 / L2 (3) And empirically, CP = 2.8 × CC - 43.9 (4)

[0047] A crimping potential of 39% corresponds to a crimping shrinkage value of 30%.

[0048] Referring here to the figures, Figure 1 is an image of the right side of both fabrics of the circular knitted fiber of Example 1A of this specification. A multifilament two-component yarn was produced by melt spinning to have a total denier of 50.7. This yarn consisted of 34 filaments. The CP was 67 and the CS was 8.5. The polymer ratio of each filament was 60% poly(ethylene terephthalate) (PET) and 40% poly(trimethylene terephthalate) (PTT). The total elongation at break was 22%, and the breaking strength was 4.3 grams per denier. The 34 individual filaments constituting the total 50.7 denier were of different deniers ranging from 1.2 denier to 2.0 denier. A standard spin finish was applied at 2.0% w / w to ensure good package formation, as well as control of friction and static electricity during the subsequent knitting and weaving processes.

[0049] Figure 2 shows images of the reverse side of both fabrics of the circular knitted textile from Example 1A.

[0050] Figure 3 shows images of the right sides of both fabrics of the circular knitted fiber from Example 1AC. Following the process of Example 1A, a multifilament two-component yarn was produced in which all 34 filaments were 1.5 dpf (denier per filament).

[0051] Figure 4 shows images of the reverse side of both fabrics of the circular knitted textile of Example 1AC. Embodiments of the present invention Embodiment 1. An elastic fabric comprising a two-component multifilament yarn having at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament are independently selected and differ in at least one of the following: (a) denier per filament, (b) ratio of the first component of the filament to the second component of the filament, (c) cross-section, and (d) combination thereof. Embodiment 2. The elastic fabric according to Embodiment 1, further comprising a second thread. Embodiment 3. An elastic fabric according to any one of Embodiments 1 to 2, further comprising a second yarn selected from the group consisting of cotton, polyester, polyurethane, polyolefin, polyamide, and combinations thereof. Embodiment 4. An elastic fabric according to any one of Embodiments 1 to 3, wherein the elastic fabric is a knitted or woven elastic fabric. Embodiment 5. An elastic fabric according to any one of Embodiments 1 to 4, wherein the denier of the two-component multifilament yarn is approximately 20 to approximately 150. Embodiment 6. An elastic fabric according to any one of Embodiments 1 to 5, wherein the first and second components of the two-component yarn described above include a polyester selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. Embodiment 7. An elastic fabric according to any one of Embodiments 1 to 6, wherein the denier per filament in the two-component multifilament yarn is in the range of about 0.8 to about 4.0. Embodiment 8. An elastic fabric according to any one of Embodiments 1 to 7, wherein the denier per filament in the two-component multifilament yarn is in the range of about 1.0 to about 3.5. Embodiment 9. An elastic fabric according to any one of Embodiments 1 to 8, wherein the ratio of the first component to the second component is approximately 30:70 to approximately 70:30. Embodiment 10. An elastic fabric according to any one of Embodiments 1 to 9, wherein the cross-section of the filament has an aspect ratio of 1.5:1 or greater. Embodiment 11. An elastic fabric according to any one of Embodiments 1 to 10, wherein the cross-section of the filament is selected from circular, elliptical, snowman, or ribbon. Embodiment 12. An elastic fabric according to any one of Embodiments 1 to 11, wherein the crimp shrinkage is approximately 0.5% to approximately 10%. Embodiment 13. An elastic fabric according to any one of Embodiments 1 to 12, wherein the crimping potential is approximately 40 CP 40% to approximately 70%. Embodiment 14. A two-component multifilament yarn according to any one of Embodiments 1 to 13, comprising at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament are independently selected and differ in at least one of (a) denier per filament, (b) ratio of the first component of the filament to the second component of the filament, (c) cross-section, and (d) method of combining them. Embodiment 15. A method for preparing a two-component multifilament yarn according to any one of Embodiments 1 to 14, comprising at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament differ in (a) denier per filament, (b) ratio of the first component to the second component of the filament, (c) cross-section, and (d) at least one combination thereof, and comprising extruding a polymer containing the first component and the second component for each filament through separate holes of a spinaret, wherein the holes differ in size, (b) have different cross-sections, (c) within each of the holes have different ratios of the first component to the second component, and (d) combinations thereof. Embodiment 16. A method for preparing a two-component multifilament yarn according to any one of Embodiments 1 to 15, comprising at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament have partial overlaps of the same properties which can be selected from (a) denier per filament, (b) ratio of the first component of the filament to the second component of the filament, (c) cross-section, and (d) combination thereof, and both the first and second are combined into a single multifilament yarn by an entanglement, twisting, or air-jet yarn processing process. Embodiment 17. A two-component multifilament yarn according to any one of Embodiments 1 to 16, comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate), wherein the two-component filament has a substantially elliptical cross-sectional shape having an aspect ratio A:B of about 2:1 to about 5:1, where A is the length of the principal axis of the fiber cross-section and B is the length of the minor axis of the fiber cross-section, the polymer interface is substantially perpendicular to the principal axis, and the cross-sectional configuration is selected from the group consisting of parallel and eccentric sheath cores. An elastic fabric according to any one of embodiments 1 to 17, comprising a two-component multifilament yarn containing 2GT / 3GT, wherein the crimp potential is about 40% to about 70% and the crimp shrinkage is about 0.5% to about 8%. An elastic fabric according to any one of embodiments 1 to 18, comprising a two-component multifilament yarn containing 2GT / 3GT, having a crimp potential of about 60% and a crimp shrinkage of about 0.5% to about 6%.

[0052] Examples Example 1A A multifilament two-component yarn was manufactured by melt spinning to have a total denier of 50.7. This yarn consisted of 34 filaments. The CP was 67 and the CS was 8.5. The polymer ratio of each filament was 60% poly(ethylene terephthalate) (PET) and 40% poly(trimethylene terephthalate) (PTT). The total elongation at break was 22%, and the breaking strength was 4.3 grams per denier. The 34 individual filaments constituting the total 50.7 denier had different deniers ranging from 1.2 denier to 2.0 denier. A standard spin finish was applied at 2.0% w / w to ensure good package formation and control of friction and static electricity during the subsequent knitting and weaving processes.

[0053] Example 1AC Following the process of Example 1A, a multifilament two-component yarn was produced in which all 34 filaments were 1.5 dpf (denier per filament).

[0054] Example 2: The multifilament yarns of Examples 1A and 1AC were knitted on a circular knitting machine, then dyed with disperse dyes in the conventional manner, and finished.

[0055] Example 3 The multifilament yarns of Examples 1A and 1AC were separately plated with 50-denier 72-filament denier

[0056] Example 4F A multifilament bicomponent yarn was produced by melt spinning to have a total denier of 50.7. This yarn consisted of 46 filaments. The CP was 50 and the CS was 5.0. The polymer ratio of each filament was 60% poly(ethylene terephthalate) and 40% poly(trimethylene terephthalate). A standard spin finish was applied at 2.0% w / w to ensure good package formation and control of friction and static electricity during the subsequent knitting and weaving processes. The multifilament bicomponent yarn was knitted on a circular knitting machine. It was dyed conventionally using disperse dyes and dried on a stent frame at 140°C. The fabric had a soft feel and desirable drape.

Claims

1. An elastic fabric comprising a two-component multifilament yarn having at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament are independently selected and differ in at least one of the following: (a) denier per filament, (b) ratio of the first component of the filament to the second component of the filament, (c) cross-section, and (d) combination thereof.

2. The elastic fabric according to claim 1, further comprising a second thread.

3. The elastic fabric according to claim 1, further comprising a second yarn selected from the group consisting of cotton, polyester, polyurethane, polyolefin, polyamide, and combinations thereof.

4. The elastic fabric according to claim 1, wherein the elastic fabric is a knitted or woven elastic fabric.

5. The elastic fabric according to claim 1, wherein the denier of the two-component multifilament yarn is about 20 to about 150.

6. The elastic fabric according to claim 1, wherein the first and second components of the two-component yarn include a polyester selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate.

7. The elastic fabric according to claim 1, wherein the denier per filament in the two-component multifilament yarn is in the range of about 0.8 to about 4.

0.

8. The elastic fabric according to claim 1, wherein the denier per filament in the two-component multifilament yarn is in the range of about 1.0 to about 3.

5.

9. The elastic fabric according to claim 1, wherein the ratio of the first component to the second component is approximately 30:70 to approximately 70:

30.

10. The elastic fabric according to claim 1, wherein the cross-section of the filament has an aspect ratio of 1.5:1 or greater.

11. The elastic fabric according to claim 1, wherein the cross-section of the filament is selected from circular, elliptical, snowman, or ribbon.

12. The elastic fabric according to claim 1, wherein the crimp shrinkage is approximately 0.5% to approximately 10%.

13. The elastic fabric according to claim 1, wherein the crimping potential is approximately 40 CP 40% to approximately 70%.

14. A two-component multifilament yarn having at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament are independently selected and differ in at least one of the following: (a) denier per filament, (b) ratio of the first component of the filament to the second component of the filament, (c) cross-section, and (d) method of combining them.

15. A method for preparing a two-component multifilament yarn having at least a first two-component filament and a second two-component filament, wherein the first filament and the second filament differ in (a) denier per filament, (b) ratio of the first component to the second component of the filament, (c) cross-section, and (d) at least one combination thereof, and the method comprises extruding a polymer containing the first component and the second component for each filament through separate holes of a spinaret, wherein (a) the holes differ in size, (b) the holes differ in cross-section, (c) in each of the holes the ratio of the first component to the second component differs, and (d) combination thereof.

16. A method for preparing a two-component multifilament yarn, wherein a first two-component filament is prepared by selecting one or more properties of (a) denier per filament, (b) the ratio of the first component to the second component of the filament, (c) cross-section, and (d) a combination thereof; a second two-component filament is prepared using one or more properties of (a) denier per filament, (b) the ratio of the first component to the second component of the filament, (c) cross-section, and (d) a combination thereof; and both the first and second two-component multifilament yarns are combined into a single multifilament yarn by an entanglement, twisting, or air-jet yarn processing process.

17. A two-component multifilament yarn comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate), wherein the two-component filaments have a substantially elliptical cross-sectional shape having an aspect ratio A:B of about 2:1 to about 5:1, where A is the length of the principal axis of the fiber cross-section and B is the length of the minor axis of the fiber cross-section, the polymer interface is substantially perpendicular to the principal axis, and the cross-sectional configuration is selected from the group consisting of parallel and eccentric sheath cores.

18. An elastic fabric comprising a two-component multifilament yarn containing 2GT / 3GT, wherein the crimp potential is about 40% to about 70% and the crimp shrinkage is about 0.5% to about 8%.

19. An elastic fabric comprising a two-component multifilament yarn containing 2GT / 3GT, wherein the crimp potential is less than about 60% and the crimp shrinkage is about 0.5% to about 6%.

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