CN112410964A

CN112410964A - Drawn yarn and fabric with multiple elastic yarns

Info

Publication number: CN112410964A
Application number: CN202011012211.9A
Authority: CN
Inventors: T·廖; R·S·P·梁
Original assignee: Apparel & Advanced Textiles Uk Ltd
Current assignee: Apparel & Advanced Textiles Uk Ltd
Priority date: 2013-01-16
Filing date: 2013-12-30
Publication date: 2021-02-26
Also published as: JP6913436B2; WO2014113207A1; EP2946032B1; EP2946032A1; US20160362819A1; BR112015016987A2; BR112015016987B1; EP2946032A4; CN105189841A; WO2014113207A9; JP7015273B2; TW201441439A; US20150354101A1; KR102158057B1; EP3943650B1; TWI649470B; EP3943650A1; KR20150105996A; JP2019167665A; JP2016507669A

Abstract

The present invention relates to a drawn yarn and fabric having a plurality of elastic yarns. An article and method comprising a core spun yarn is disclosed. The core spun yarn comprises a hard fiber sheath and two sets of elastic fibers, wherein the sets of elastic fibers have different properties. The characteristics may differ in one or more respects, such as having different deniers, compositions or drafts. One or both of the sets of elastic fibers may be pre-coated.

Description

Drawn yarn and fabric with multiple elastic yarns

The application is a divisional application of an invention patent application with application date of 2013, 12 and 30, application number of 201380074782.7 and the name of 'stretched yarn and fabric with multiple elastic yarns'.

Background

Technical Field

The present invention relates to the manufacture of stretch composite yarns and fabrics. And more particularly to a fabric and method that includes two sets of elastic core fibers within one yarn.

Brief description of the related Art

Stretch fabrics with elastic composite yarns have long existed in the market. Fabric and garment manufacturers generally know how to manufacture fabrics with the correct quality parameters to obtain fabrics acceptable to the consumer. In the currently commercially available fabrics, there is only one system of elastic fibers within the yarn and fabric. An elastic fiber provides dual functionality: stretchability and recovery. It is difficult to obtain a fabric with easy stretch, high recovery and low shrinkage properties.

Easy stretch is an important feature of comfortable garments. For more comfortable garments, the fabric can be easily stretched out when the garment is worn on a person's body and moved. They have low pressure exerted on the body by the clothing. The garment can be cut to achieve a more streamlined appearance and better fit to the body while still maintaining comfort for the wearer during movement. The performance can be achieved by a low fabric tensile modulus, which is achieved by minimizing the resistance of the garment to the body demands of the wearer during exercise.

However, for fabrics with low tensile modulus, a typical quality problem is that the fabric does not return quickly to its original size and shape after being stretched too far apart in some parts of the body, such as in the knees, hips and waist, especially for fabrics with high levels of stretch. Generally, when the tensile modulus is low, the fabric has low recovery ability. Consumers find sagging and sagging problems after prolonged wear.

In contrast, to obtain a fabric with good recovery, additional shrinkage forces are required within the fabric. Higher levels or more of strong elastic fibers may be added to the fabric. However, these fabrics have high modulus of elongation and higher restraining force. Consumers complain of higher garment pressure and uncomfortable restraints during wear and movement. At the same time, the fabric has poor dimensional stability. Heat setting is a necessary process to control fabric shrinkage. Garment comfort and freedom of movement require fabric shape retention and recovery functions to give way. There remains a need for fabrics having easy stretch, high recovery, and low shrinkage properties.

Composite elastic yarns have been known for many years. For example, with U.S. patent nos. 4470250, 4998403, 7134265, 6848151, elastomeric fibers such as spandex (spandex) are covered with relatively inelastic fibers to facilitate acceptable handling of knitting or weaving, and to provide elastic composite yarns having acceptable characteristics for various end use fabrics. In US patent applications US 2008/0268734a1 and USA 2008/0318485a1, rigid filaments and elastic filaments are used together as a core in a core spun yarn.

Therefore, there is a need to produce a stretched woven fabric having easy stretching, easy handling, low shrinkage, friendly garment manufacturing, and excellent recovery and low growth rate.

Summary of The Invention

One aspect includes a method for making a composite yarn having two distinct sets of elastic core fibers, referred to as a dual elastic composite yarn. Also, dual elastic composite yarns and stretch fabrics and garments made from the yarns are included.

According to a first embodiment of the method, two sets of elastic fibers and hard fibers having different properties are covered together to form a composite yarn, wherein the two sets of elastic fibers are stretched to different drafts of their original length during the yarn covering process. The elastomeric fiber can be bare spandex from 11 to 560 dtex, and the hard fiber has a yarn count from 10 to 900 dtex. One suitable hard yarn is cotton. Elastic core fiber I and elastic core fiber II are independently selected from elastomeric or non-elastomeric fibers.

According to a second embodiment of the method, two groups of elastic fibers (elastic core fiber I and elastic core fiber II) having different properties and hard fibers are cladded together to form a composite yarn, wherein the two groups of elastic fibers have different polymer compositions and have different stress-strain behavior. The elastomeric fiber can be bare spandex from 11 to 560 dtex, and the hard fiber has a yarn count from 10 to 900 dtex. One suitable hard yarn is cotton.

According to a third embodiment of the method, two different sets of elastic core fibers (elastic core fiber elastic I and elastic core fiber II) and hard fibers are covered together to form a composite yarn, wherein at least one set of elastic core fibers is a pre-covered elastic yarn. Another set of elastomeric core yarns may be bare spandex or pre-covered elastomeric yarns. Bare spandex yarn denier is from 11 to 560 dtex, and hard fiber yarn count is from 10 to 900 dtex. One suitable hard yarn is cotton.

According to a fourth embodiment of the method, two different sets of elastic core fibers and hard fibers are covered together to form a composite yarn, wherein at least one elastic core fiber is a non-elastomeric drawn fiber. Another set of elastic core yarns may be bare elastomers such as spandex. Bare spandex yarn denier is from 11 to 560 dtex, and hard fiber yarn count is from 10 to 900 dtex. One suitable hard yarn is cotton.

The fabric is made by using a dual elastic yarn produced by one of these alternative methods. Dual elastic yarns are used in at least one direction of the fabric. Any form of fabric may be used including woven, circular knit, warp knit and narrow width fabrics. Further processing may include scouring, bleaching, dyeing, drying, anti-wrinkle finishing, singeing, desizing, mercerizing, and any combination of the steps described. The resulting stretched fabric may be formed into a garment.

Brief Description of Drawings

The detailed description will proceed with reference being made to the following drawings, wherein like reference numerals refer to like elements, and wherein:

figure 1 shows a core spun yarn with two elastic cores.

Fig. 2 is a schematic depiction of a core spinning apparatus with two drafting devices for two bare elastic fibers.

Fig. 3 is a schematic depiction of a core spinning apparatus including two drafting devices with weighted rollers.

Fig. 4 is a schematic depiction of a core spinning apparatus with two drafting devices for a bare elastomeric fiber and a pre-coated elastomeric yarn.

Detailed Description

Elastomeric fibers are commonly used to provide stretch and elastic recovery in woven fabrics and garments. An "elastomeric fiber" is a continuous filament (optionally an aggregated multifilament) or a plurality of filaments, free of diluent, having an elongation at break of more than 100% independent of any crimp. Stretching the elastomer fiber to twice as long as the elastomer fiber in the step (1); (2) keeping for one minute; and (3) upon release, shrinks to less than 1.5 times its original length within one minute of being released. As used herein, "elastomeric fiber" refers to at least one elastomeric fiber or filament. The elastomeric fibers include, but are not limited to, rubber filaments, biconstituent filaments and elastomeric polyetheresters (elastoester), lastol, and spandex.

"spandex" is a manufactured filament in which the filament-forming substance is a long-chain synthetic polymer composed of at least 85% by weight of a segmented polyurethane.

"elastomeric polyetheresters" are manufactured filaments in which the fiber-forming substance is a long-chain synthetic polymer composed of at least 50% by weight of aliphatic polyethers and at least 35% by weight of polyesters.

"biconstituent filament" continuous filaments or filaments comprising at least two polymers adhered to each other along the length of the filament, each polymer being of a different general class, for example, elastomeric polyetheramide cores and polyamide sheaths having lobes or wings.

"Lastol" is a fiber of a crosslinked synthetic polymer, having a low but significant degree of crystallinity, consisting of at least 95% by weight of ethylene and at least one other olefin unit. Such fibers are elastic and substantially heat resistant.

"polyester bicomponent filament" means a continuous filament comprising a pair of polyesters intimately adhered to one another along the length of the fiber such that the fiber cross-section is, for example, a side-by-side eccentric sheath-core or other suitable cross-section from which useful crimp can be produced. Fabrics made with such filaments as Elasterell-p, PTT/PET bicomponent fibers have excellent recovery characteristics.

"non-elastomeric elastic fiber" refers to a drawn filament that does not contain elastomeric fibers. However, the yarn must have a recoverable stretch of greater than 20%, as measured by ASTM D6720 method, such as textured PPT drawn filaments, textured PET drawn filaments, bicomponent drawn filament fibers, or PBT drawn filaments.

A "pre-coated elastomeric yarn" is a yarn that is surrounded by, twisted with, or interlaced with a hard yarn prior to the core-spinning process. The pre-coated elastic yarn comprising elastomeric fibers and hard yarn is also referred to as "pre-coated yarn" in the present specification. Hard yarn covering is used to protect the elastomeric fibers from abrasion during the textile process. The abrasion can lead to breakage of the elastomeric fibers, as well as subsequent process interruptions and undesirable fabric non-uniformities. Furthermore, the coating helps to stabilize the elastic behavior of the elastomeric fibers so that the elongation of the pre-coated elastic yarns can be more uniformly controlled during the textile process than with bare elastomeric fibers. The pre-coated yarns may also increase the tensile modulus of the yarn and fabric, which helps to improve fabric recovery and dimensional stability.

The pre-coated yarn comprises: (a) elastomeric fibers singly wrapped with a hard yarn; (b) elastomeric fibers double wrapped with hard yarn; (c) continuously coating (i.e., core spun or core-s ρ inning) elastomeric fibers with staple fibers, followed by twisting during winding; (d) interlacing and entangling the elastomer and hard yarn together with air jets; and (e) twisting the elastomeric fiber and the hard yarn together.

A "dual elastic composite yarn" is a composite yarn comprising two sets of elastic core fibers with a single yarn covered by a hard staple fiber sheath. The term "dual elastic yarn" is used interchangeably in this specification.

The drawn fiber of some embodiments includes a dual elastic core spun yarn in the fill direction. In some embodiments, fabrics, particularly high stretch fabrics, are obtained with unexpectedly high recovery properties. This is achieved by using a core spun yarn comprising two different elastic fibers having different tensile properties. Those skilled in the art will recognize that where weft stretch is desired, the fabric may include the core spun yarn with the bielastic fiber in the weft direction.

As shown in fig. 1, a dual elastic yarn 8 according to the invention will necessarily comprise two elastic filament cores: elastic core I (4 in fig. 1) and elastic core II (6 in fig. 1). The elastic core filament is preferably surrounded along its entire length by a fibrous sheath 2 comprising woven staple fibers.

Fig. 2 shows one embodiment of a representative core spinning apparatus 40. Two separate

fiber drawing devices

46 and 64 are mounted on the machine. During the core spinning process, the elastic core filament I48 and the elastic core filament II 60 are placed on the

transfer rollers

46 and 64, respectively, and combined with the hard yarn to form a composite core spun yarn. The core elastic filaments from tube 48 and tube 60 are unwound in the direction of

arrows

50 and 62 by the action of positively driven feed rolls 46 and 64.

Feed rollers

46 and 64 serve as supports for tubes 48 and 60 and transport the elastic fibers of yarns 52 and 66 at a predetermined speed.

The stiff fibers or yarns 44 are unwound from the tube 54 to merge with the elastic core filaments 52 and 66 at the front set of rollers 42. The combined elastic core filaments 52, 66 and hard fibers 44 are cored together at the spinning device 56.

The elastic core filament I52 and the elastic core filament II 66 are stretched (drafted) before they enter the front roller 42. The elastic filaments are stretched by the speed difference between the

feed roll

46 or 64 and the front roll 42. The forward roller 42 is transported at a speed greater than the

feed rollers

46 and 64. The speed of the feed rolls 46 and 64 is adjusted to obtain the desired draw or draw ratio.

The draw ratio is typically 1.01X to 5.0X times (1.01X to 5.0X) as compared to non-drawn fibers. Too low a draw ratio can result in low quality yarns and non-centered elastomeric filaments having grin-through. Too high a draw ratio will result in breakage of the elastic filaments and core voids.

Fig. 3 shows another embodiment of a representative core spinning apparatus 40. Elastic core I is a bare elastic filament 48 and elastic core II 12 is a pre-coated elastic yarn. The elastic core II from the tube 12 is unwound in the direction of the arrow 62 by the action of a feed roll 64 driven positively. The weighted roller 66 serves to maintain stable contact between the elastic core II and the feed roller 64 in order to transport the elastic core II of the yarn 68 at a predetermined speed. The other elements of fig. 3 are shown in fig. 2.

Fig. 4 shows another embodiment of a representative core spinning apparatus 40. Elastic core I is a bare elastic filament 48 and elastic core II 12 is a pre-coated elastic yarn. The elastic core II from the tube 12 is removed from the end and then passed through the tension control device and the guide bar. The tension device is used for keeping the tension of the yarn at a predetermined level stably. The stretch ratio of bare elastic fibers is typically 1.01X to 5.0X (1.01X to 5.0X) times that of non-stretched fibers. The other elements of fig. 4 are shown in fig. 2.

According to a certain embodiment of the method, two elastic fibers and a hard fiber having different properties are covered together to form a composite yarn, wherein the two elastic fibers are stretched to different drafts of their original length during the yarn covering process. The draft of the two elastic fibers can be selected between 1.01X times to 5.0X times. For two core elastic fibers having different deniers or different filament counts, the stretch ratios of elastic core I and elastic core II may be different from each other, depending on the elastic fiber properties and fabric quality requirements. In many cases, one core is drawn more to provide high stretch properties, while the other core is drawn less to provide low shrinkage and high recovery to the fabric.

In conventional fabrics, if heat setting is not used to "set" the spandex, the fabric can have high shrinkage, excessive fabric weight, and excessive elongation, which can lead to a negative experience for the consumer. Excessive shrinkage during the fabric finishing process can cause creases on the fabric surface during handling and home laundering processes. The creases created in this way will generally be difficult to remove by ironing.

By using low draw in one elastic core fiber, the high temperature heat setting step in the process can be avoided. This new process can reduce thermal damage to specific fibers (i.e., cotton) and thus can improve the hand of the finished fabric. The fabric of some embodiments may be prepared without a heat-setting step, including where the fabric is to be made into a garment. As another advantage, heat sensitive hard yarns can be used in new processes for making elastic shirt fabrics, thus increasing the possibilities for different and improved products. In addition, the shorter process has productivity benefits for the fabric manufacturer.

It has been surprisingly found that a core spun yarn having two different elastic core fibers has a higher elongation and recovery than a core spun yarn made of a single core elastic filament having the same denier. For example, a core spun yarn having two cores of 30D/3 filament spandex plus 40D/4 filament spandex has greater recovery at the same draft than a core spun from a single core of 70D/5 filament yarn. Thus, we can make a core spun yarn with higher draw ratio and higher recovery by using the same amount of spandex.

Two elastic fibers with different characteristics can makeCoated with and with a stiff fiber sheath to form a composite yarn, wherein the two elastic fibers may have different polymer compositions and have different stress-strain behaviors. One example is the use of two spandex fibers with different heat-set efficiencies together in one core spun yarn, as is standard

Spandex fiber T162C and easy to shape

Fiber T562B. The fabric can be shaped more easily than the fabric

The fibres having a heat-setting temperature lower than the standard

Heat-setting the fiber at a heat-setting temperature. Thus, the fabric is only partially heat set, which provides acceptable fabric shrinkage while providing good stretch and growth rates.

Another example is a core-spun comprising an elastic core I with a high tensile modulus and an elastic core II with a low tensile modulus. The elastic core I provides the fabric with high recovery and low fabric growth rate, while the elastic core II with low modulus provides the fabric with easy stretch, lower shrinkage, resulting in a fabric with easy stretch, high retention and high dimensional stability. Elastic fibers having different chemical compositions may also be combined with a core spun yarn, such as the polyolefin elastic fibers Lastol and spandex. Spandex fiber provides high recovery, while Lastol fiber imparts good heat resistance and lower shrinkage.

The combination of elastic core I and elastic core II can be elastic bare fiber plus elastic bare fiber; or the elastic bare fiber plus the pre-coated elastic yarn, or the pre-coated elastic yarn plus the pre-coated elastic yarn. The bare elastic fiber can be about 11 to about 444 decitex (denier-about 10D to 400D), including 11 to about 180 decitex (denier 10D to about 162D).

Pre-coated elastic yarns include various types, such as single wrapping of elastomeric fibers with hard yarns; double wrapping the elastomer fibers with hard yarn; continuously coating (i.e., core spun) the elastomeric fiber with staple fiber, followed by twisting during winding; interlacing and entangling the elastomer and hard yarn together with air jets; and twisting the elastomeric fiber and the hard yarn together. Preferred pre-coated elastomeric yarns are spandex air-jet coated yarns with textured polyester and nylon filaments, such as 40D or 70D spandex with 50D to 150D polyester air-coated yarns. The pre-coated elastic yarn is made in a separate machine prior to the core-spun yarn process.

The pre-coated elastic yarn can be present in any desired amount, for example from about 5 wt% to about 35 wt%, based on the total dual elastic yarn weight. The linear density of the pre-coated yarns ranges from about 15 denier (16.5 dtex) to about 900 denier (990 dtex), including from about 30 denier to 300 denier (33 dtex to 330 dtex). When the yarn titer ratio between the pre-coated yarn and the total dual elastic yarn is less than 35%, the fabric does not have significant grin-through. After the finishing process, the two elastic core fibers included in the pre-coated yarn are not visible.

The bare elastic fiber (prior to being covered to form the pre-covered yarn) may have a denier of about 11 to about 444 decitex (denier-about 10D to about 400D), including 11 to about 180 decitex (denier 10D to about 162D). During the pre-coating process, the elastic fiber is drawn between 1.1X and 6X its original length. In the pre-coating, the elastic fibers are pre-coated with one or more hard yarns, wherein the hard yarns have a denier of from 10 to 600.

Another combination of elastic core fibers I and elastic core fibers II may be one set of elastic bare fibers plus another set of non-elastomeric elastic fibers. The non-elastomeric elastic fibers may be textured PET drawn filaments, textured PPT drawn filaments, bicomponent fibers, or PBT drawn fibers. It has been surprisingly found that the properties of core-spun yarns and fabrics change significantly when using a non-elastomeric elastic fiber having a recoverable stretch greater than 20% as one of the elastic core fibers. The fabric has high stretch and high recovery. The linear density of the non-elastomeric elastic fibers may range from about 15 denier (16.5 dtex) to about 450 denier (495 dtex), including from about 30 denier to 150 denier (33 dtex to 165 dtex). When the denier is too high, the fabric can have a significant amount of grin-through.

The elastomeric fiber content in the dual elastic core spun yarn is between about 0.1% to about 20%, including from about 0.5% to about 15%, and about 5% to about 10%, by weight of the yarn. The elastomeric fiber content in the fabric may be from about 0.01 wt% to about 10 wt%, including from about 0.5 wt% to about 5 wt%, based on the total fabric weight.

The staple sheath fiber (staple sheath fiber) in the dual elastic yarn may be a natural fiber such as cotton, wool or linen. They can also be short synthetic or synthetic fibers, poly (ethylene terephthalate) and poly (trimethylene terephthalate) fibers, polycaprolactam fibers, poly (hexamethylene adipamide) fibers, acrylic fibers, modacrylic fibers, acetate fibers, rayon fibers, nylon, and combinations thereof, in a single component.

The dual elastic yarns may be used to make stretch fabrics on which various weave patterns may be applied, including plain, poplin, twill, oxford, mini-jacquard, sateen, satin, and combinations thereof. The fabrics of some embodiments may have an elongation from about 10% to about 45% in the warp or/and weft direction. The fabric may have a shrinkage of about 15% or less after washing. The stretch woven fabric may have a good cotton hand. The garment may be made from the fabric described herein.

The warp yarns may be the same as or different from the weft yarns. The fabric may be stretched only in the weft direction, or it may be biaxially stretched, with useful stretch and recovery properties being manifested in both the warp and weft directions.

Air-jet looms, rapier looms, projectile looms, water-jet looms and shuttle looms can be used. The dyeing and finishing process is very important in producing satisfactory fabrics. The fabric can be finished in a continuous range process and a piece dye jet process. The conventional equipment present in continuous finishing plants and piece-dyeing plants is generally sufficient for the treatment. Standard finishing process sequences include preparation, dyeing and finishing. Standard processing methods for elastomeric wovens, including singeing, desizing, scouring, bleaching, mercerizing, and dyeing, are generally satisfactory in preparation and dyeing processes.

The analysis method comprises the following steps:

recoverable stretch of yarn

Recoverable stretch of the elastic fibers used in the examples was measured as follows. Each yarn sample was formed into a hank of 5000+/-5 total denier (5550 dtex) using a hank winder at a tension of about 0.1 grams per denier (0.09 dN/tex). The skein was conditioned at 70 ° F (+/-2 ° F) (21 ℃ C. +/-1 ℃ C.) and 65% (+/-2%) relative humidity for at least 16 hours. The skein was suspended substantially vertically on a bracket, a 6mg/den (5.4mg/dtex) weight (e.g., 30 grams for 5550 dtex skein) was suspended at the bottom of the skein, allowing the weighted skein to reach equilibrium length, and the length of the skein was measured to 1mm accuracy and recorded as "Cb". For the durability test, a weight of 5.4mg/dtex was left on the skein. Next, a 1030g weight (206 mg/d; 185.4mg/dtex) was suspended at the bottom of the skein and the length of the skein was measured, accurate to 1mm and recorded as "L"_b”。

The weight of 1030g was removed and the skein was then immersed in boiling water for 10 minutes in water at 100 ℃, after which the skein was taken out of the water and conditioned as above for 16 hours. This step is designed to simulate a commercial fabric relaxation process, which is one way to create fabric stretch. The length of the skein was measured as above and recorded as "C_a". A1030 g weight was again hung on the skein, and the skein length was measured as above and recorded as "L_a". According to formula CC_a＝100x(L_a-C_a)/L_aCalculating the recoverable percent elongation (percent) "CC" of the relaxed yarn_a". According to the formula Cs (%) ═ 100X (L)_b-L_a)/L_bAnd calculating the yarn shrinkage.

Elongation (elongation) of woven fabric

The elongation% of the fabric is evaluated at a particular load (i.e., force) in one or more fabric stretch directions, which is the direction of the composite yarns (i.e., weft, warp, or weft and warp). Three samples having a size of 60cmx6.5cm were cut out of the fabric. The long dimension (60cm) corresponds to the direction of stretching. The sample was partially disassembled to reduce the sample width to 5.0 cm. The samples were then conditioned at 20 ℃ +/-2 ℃ and 65% +/-2% relative humidity for at least 16 hours.

A first fiducial was prepared across the width of each sample at 6.5cm from the end of the sample. A second fiducial was prepared across the width of the sample at 50.0cm from the first fiducial. Excess fabric from the second datum to the other end of the sample is used to form and sew loops into which metal pins can be inserted. The notches are then cut apart in a ring so that a weight can be attached to the metal pin.

The sample non-loop end was clamped and the fabric sample was hung vertically. A 17.8 newton (N) weight (4LB) was attached to the metal pin through the suspended fabric loop so that the fabric sample was stretched by the weight. The sample was "exercised" by allowing it to be stretched by a weight for three seconds, and then the force was manually released by lifting the weight. This cycle was carried out three times. The weight is then allowed to hang freely, thereby stretching the fabric sample. The distance (in millimeters) between the two fiducials is measured when the fabric is under load, and is designated as ML. The original distance between the datums (i.e., the unstretched distance) is designated GL. The% fabric elongation for each individual sample was calculated as follows:

elongation% (E%) ((ML-GL)/GL) x100

The final result was taken as the average of the three elongation results.

Growth rate of woven fabric (unrecovered elongation)

After stretching, the non-grown fabric will return exactly to its original length before stretching. However, a stretched fabric will generally not recover completely and will lengthen slightly after prolonged stretching. This slight increase in length is referred to as "growth".

The fabric elongation test described above must be completed before the growth rate test. Only the fabric was tested for the direction of stretch. For the biaxially oriented fabric, the test was performed in both directions. Three samples, each 55.0cm x 6.0cm, were cut from the fabric. These are different from the samples used in the elongation test. The direction of 55.0cm should correspond to the stretching direction. The sample was partially disassembled to reduce the sample width to 5.0 cm. The samples were conditioned at temperature and humidity as in the elongation test above. Two fiducials spaced exactly 50cm apart were drawn across the width of the sample.

The known elongation% (E%) from the elongation test was used to calculate the length of the sample at 80% of this known elongation. The calculation is as follows:

e (length) at 80%, (E%/100) x0.80xl,

where L is the original length between references (i.e., 50.0 cm). The sample was clamped at both ends and stretched until the length between the benchmarks equals L + E (length) as calculated above. The stretching was maintained for 30 minutes, the stretching force was released after the passage of time, and the sample was allowed to hang freely and relax. After 60 minutes,% growth was measured as follows:

growth rate [% ], [% ] (L2 x 100)/L,

where L2 is the increase in length between the standards of the sample after relaxation and L is the original length between the standards. The growth rate% of each sample was measured, and the results were averaged to determine the number of growths.

Shrinkage of woven fabric

Fabric shrinkage was measured after washing. The fabric is subjected to a first conditioning at temperature and humidity as in the elongation and growth rate test. Two samples (60cm x 60cm) were then cut from the fabric. The sample was taken at least 15cm away from the selvedge. Four sided boxes of 40cm x 40cm were marked on the fabric samples.

The samples were washed in a washing machine with the samples and loaded fabric. The total washing machine load was 2kg of air drying material and no more than half of the washes consisted of test samples. The laundry was gently washed at a water temperature of 40 ℃ and rotation. A cleaning dose of 1g/l to 3g/l is used, depending on the hardness of the water. The sample was placed on a flat surface until dry and then conditioned at 20 ℃ +/-2 ℃ and 65% +/-2% rh relative humidity for 16 hours.

The fabric sample shrinkage was then measured in the warp and weft directions by measuring the distance between the marks. The shrinkage C% after washing was calculated as follows:

C％＝((L1-L2)/L1)x 100，

where L1 is the original distance between the labels (40cm) and L2 is the distance after drying. The average of the samples was sampled and reported in the weft and warp directions. Negative shrinkage figures reflect expansion, which is possible in some cases due to hard yarn behavior.

Weight of fabric

The woven fabric samples were die stamped using a 10cm size die. Each cut woven fabric sample was weighed in grams. The "fabric weight" was then calculated as grams per square meter.

Example (b):

the following examples demonstrate the invention and its ability to be used to make various fabrics. The invention is capable of other and different embodiments and its several details are capable of modifications in various obvious aspects all without from the scope and spirit of the present invention. Accordingly, the embodiments should be considered as illustrative in nature and not restrictive.

For each of the following denim fabric examples, 100% cotton open end spun yarns or ring spun yarns were used as warp yarns. For denim fabric, it contains two types of yarns (count yarn): 7.0Ne OE yarns and 8.5Ne OE yarns with irregular patterns. Prior to warping, the yarn was indigo dyed in the form of a rope. Then, the size is set and weaving and warping are performed. For the bottom weight fabric, the warp yarn was 20Ne 100% cotton ring spun yarn. The size is set and weaving and warping are performed.

Table 1 lists four examples of core spun yarns with one conventional elastic core filament and an inventive yarn containing two sets of elastic cores.

Several core spun yarns with a dual elastic core fiber are used as weft yarns. Various elastic core fibers are used in the core, including bare spandex, pre-coated polyester-

Spandex fiber or pre-coated nylon/spandex yarn. Table 2 lists the materials and treatment used to make the core spun yarn of each example. Table 3 shows a detailed fabric structure and performance summary for each fabric.

Spandex is available from Invista, s.l., Wichita, KS. For example, in the column entitled spandex, 40D refers to 40 denier; 3.5X means applied by core-spun spinning machine

Drawing (machine drawing). In the column entitled "rigid sheath yarn", 20's are the linear densities of the spun yarns measured by the English Cotton Count System (English Cotton Count System). The remaining entries in tables 1 and 2 are clearly labeled.

A stretch woven fabric was then made using the core spun yarn of each example in table 2. Table 3 summarizes the yarns used in the fabric, the weave pattern, and the quality characteristics of the fabric. Some additional comments for each of the examples are given below. Unless otherwise specified, the fabric is woven on a denier air jet or rapier loom. The loom speed was 500 picks per minute. The width of the fabric in the loom and greige goods states is about 76 inches and about 72 inches, respectively. The loom has double weaving and warping capability.

Each gray fabric in the examples was finished by a jiggle dye machine. Each woven fabric was made up at 49 ℃ with 3.0% by weight

64(Sybron Inc.) Pre-scouring 10And (3) minutes. Then, the mixture was cooled at 71 ℃ with a cooling medium of 6.0% by weight

(Dooley Chemicals.LLC Inc.) and 2.0% by weight

LFH (E.I. DuPont Co.) desizing for 30 minutes, and then using 3.0 wt.% at 82%

64. 0.5% by weight

LFH and 0.5 wt.% trisodium phosphate were scoured for 30 minutes. After the fabric was finished, it was dried in a tenter frame at 160 ℃ for 1 minute.

Exemplary yarn a: typical core spun yarns have an elastic core fiber.

This is not an innovative yarn. The core-spun yarn is a 40d yarn with a cotton skin covering

16Ne of spandex fiber. In the course of the coating treatment process,

the draft of the fiber was 3.5X. The cotton twist level TM is 18 strands per inch. The yarn had a recoverable stretch of 17.71% after boiling.

Exemplary yarn B: core-spun yarn with two types of core elastic fibers

The core-spun yarn has two groups covered by cotton skin

16Ne of spandex fiber. Elastic core I fiber was 20D T162B, and elastic core II fiber was also 20D T162B. The total denier of the elastic fiber was 40 denier. In the course of the coating treatment process,

the draft of the fiber was 3.5X. The cotton twist level TM is 18 strands per inch. Thus, the core spun yarn had the same structure as the exemplary yarn A, including the yarn count,

Fiber denier and yarn twist level except for having 2 sets of core elastic filaments instead of one end of the core spun yarn. The recoverable stretch of this yarn was 20.63% higher than the yarn in sample a by 2.92 unit percent. This means that yarns with two sets of filament cores have a higher recoverable stretch at the same spandex content than yarns with one set of filament cores. In this way, the inventive yarn can provide high stretch and high recovery to the fabric by using the same amount of elastic fiber.

Exemplary yarn C: typical core spun yarns have an elastic core fiber.

This is not an innovative yarn. The core-spun yarn is a 70d yarn with a cotton skin covering

16Ne of spandex fiber. In the course of the coating treatment process,

the draft of the fiber was 3.8X. The cotton twist level TM is 18 strands per inch. The yarn had a recoverable stretch of 38.71% after boiling off and the yarn had a shrinkage of 2.28.

Exemplary yarn D: core-spun yarn with two types of core elastic fibers

The core-spun yarn has two groups covered by cotton skin

16Ne of spandex fiber. Elastic core I fiber was 30D T162B and elastic core II fiber was 40D T162B. The total denier of the elastic fiber was 70 denier. In the coating process, two kinds

The draft of the fiber was 3.8X. The cotton twist level TM is 18 strands per inch. Thus, the core spun yarn has the same structure as exemplary yarn C, except that there are 2 sets of core elastic filaments instead of one set of core spun yarn. The recoverable stretch of this yarn was 40.88% which was 2.17 unit percent higher than that of yarn sample C. This means that yarns with two sets of filament cores have a higher recoverable stretch at the same spandex content than yarns with one set of filament cores. In this way, the inventive yarn can provide high stretch and high recovery to the fabric by using the same amount of elastic fiber.

Example 1: typical stretch woven bottom weight fabrics

This is a comparative example not according to the present invention. The warp yarn is a ring spun yarn with 40/2Ne count. The weft yarns being of 40D

20Ne cotton of the core yarn.

The draft was 3.5X. The weft yarns are typical drawn yarns used in typical drawn woven card fabrics. Loom speed was 500 picks per minute at a pick level of 56 picks per inch. Table 3 summarizes the test results. The test results show that, after finishing, the fabric has a weight (8.95 g/m)²) Stretch (37.6%), width (50.5 inches), washing shrinkage in the weft direction (0.91%), and fabric growth (8.7%). The data show that the drawn yarn and fabricThe combination of structures results in a high fabric growth rate.

Example 2: stretch fabric with dual elastic fibers

The sample had the same fabric construction as example 1. The only difference is the use of 20s weft yarns containing dual core elastic fibers: 40D with 3.5X draft

Fibers and 40d with 1.8X draft

A fiber. The warp yarn was 40/2Ne ring cotton yarn. The loom speed was 500 picks per minute at 56 picks per inch. Table 3 summarizes the test results. The sample is clearly shown to have similar elongation but a lower level of fabric growth (6.4%). Thus, by using two different drafts of the elastic core fiber within the same yarn, the covered yarn and fabric can obtain different characteristics. For example, high draft in elastic core I fibers results in a fabric with high stretch, while lower draft in elastic core II fibers results in a fabric with low growth rate, high recovery, but without increasing fabric shrinkage. In this way, a fabric with high stretch, high recovery and low shrinkage can be produced.

Example 3: stretch fabrics containing dual elastic fibers

The sample had the same fabric construction as example 1. The only difference is the use of a core spun yarn in the weft: 40D T162B with 3.5X draft

Fibers and 40d easy-set with 3.5X draft

A fiber. The warp yarn was 20Ne 100% cotton ring spun yarn. A 3/1 twill weave pattern was applied. The finished fabric had a weight (9.19 g/m)²) 38.4.0% elongation and 7.9% growth rate in the weft direction. Clearly showing easy setting in the elastic core II

The fibers maintained the fabric stretch level while reducing the fabric growth rate from 8.7% in example 1 to 7.9%.

Easy to shape

The fibers can be heat-set at about 170 ℃ with the temperature ratio T162B

The heat-set temperature of the fiber was about 20 c lower. Thus, when the fabric is heat-set at a temperature between 170 ℃ and 190 ℃, the fabric portion is heat-set. Is only easy to shape

The fibers were set, while T162B was not. In this way, the fabric maintains better stretch and recovery while the shrinkage remains below a certain level.

Example 4: stretch fabrics with spandex and elastomeric polyolefin fibers

The warp yarn is a mixed open end yarn of 7.0Ne count and 8.4Ne count. Prior to warping, the warp yarns were indigo dyed. The weft yarns are of 40D T162B

A 16Ne core spun yarn of spandex and 40D elastomeric polyolefin fiber.

The fibers and elastic polyester fibers were drawn 3.5X during the coating process. Table 3 lists the fabric properties. Fabrics made from the yarn exhibit good cotton hand, good elongation (47.8%) and good recovery (6.5% growth). All test results indicate that the combination of spandex and elastomeric polyolefin filaments can produce good fabric stretch and growth rates. The fabric did not grin through. The elastic filaments are not visible from both the fabric surface and the fabric backside.

Compared to spandex, elastic polyolefin fibers or Lastol fibers have lower recovery power, but better heat resistance, better chemical resistance, low fabric shrinkage, and good cotton touch. Fabrics containing spandex and elastomeric polyolefins can provide good stretch and good recovery, with better heat resistance, low shrinkage, and better chemical resistance, such as chlorine resistance in swimming pools and in denim bleaching.

Example 5: stretch fabrics containing spandex and pre-coated elastomeric yarn

The sample had the same fabric construction as example 1. A core-spun yarn differing in the fill direction, said core-spun yarn comprising a bare 40D yarn in the core of the yarn

Fiber and a pre-coated elastic yarn (40D/34 fNylon/40D)

Air-covered yarn). Bare 40D

In elastic yarns in which the draft of the fibres is 1.8X and which are previously covered

The draft of the fiber was 3.2X. This fabric uses the same warp yarns and structure as in example 1. In addition, the weaving and finishing processes were the same as in example 1. Table 3 summarizes the test results. We can see that the sample has good elongation (35.9%), good washing shrinkage in the weft direction (0.65%) and good fabric growth (5.3%). The fabric appearance and hand feel are very excellent. Adding pre-coated elastic yarn (40D/34f Nylon/40D)

Fiber AJY yam yarn) the fabric growth rate decreased significantly.

Example 6: stretch fabrics containing spandex and pre-coated elastomeric yarn

The sample had the same fabric construction as example 5. The only difference is that 40D is bare during the coating process

And (4) drafting the fiber. Exposed

The fiber draft was 3.5X and 1.8X in example 5. The weight of the fabric is 8.96OZ/yd²And the weft elongation was 37.8%. The fabric had a very low growth rate in the weft direction (5.9%). The samples also demonstrate that the addition of additional elastic composite yarns can produce high performance stretch fabrics with low growth rates. The dual elastic yarns resulted in fabric growth rates from 8.7% to 5.9% in example 1. The increased draw also resulted in higher weight and draw ratios compared to example 5.

Example 7: stretched denim comprising spandex and pre-coated elastic yarn

This example has the same warp yarns and the same fabric structure as example 4. The warp yarn is a mixed open end yarn of 7.0Ne count and 8.4Ne count. Prior to warping, the warp yarns were indigo dyed. The weft yarns being of 40D

Spandex and 50D/24f polyester 40D

A 16Ne core spun yarn of a fiber air jet covered yarn.

The draw in the bare and composite cores was 3.5X and 1.8X. The sample was an innovative fabric. The loom speed was 500 picks per minute at a pick level of 44 picks per foot. Table 3 summarizes the test results. The test results show that after washing, such fabrics have a weight (12.80 OZ/Y)²) 35.3% weft stretch in weftAnd a growth rate of 3.5%.

Example 8: stretched denim comprising spandex and pre-coated elastic yarn

This example has the same warp yarns and the same fabric construction as example 7, except in the pre-coated elastic yarns

Fiber draw (2.6X draw in example 8 versus 1.8X draw in example 7). Table 3 summarizes the test results. It is clear that the sample has a good elongation (40.4% weft) compared to sample 7.

Example 9: stretch fabrics with spandex and PBT stretch fibers

This example has the same warp and the same fabric construction as examples 7 and 8, except that 50D/26f PBT drawn fiber was used as the elastic core II fiber. The bare 50D/26f PBT fiber had a recoverable tensile of 40.23% and a shrinkage of 3.44% as measured by ASTM D6720 method. Elastic core I

The fiber was drawn 3.5X during the coating process. Table 3 lists the fabric properties.

Fabrics made from the yarn exhibit good cotton hand, good stretch (40.7%) and good recovery (6.0% growth). All test results indicate that the combination of spandex and non-elastomeric drawn filaments can produce good fabric stretch and growth rates. The fabric does not grin through; the elastic filaments are not visible from both the fabric surface and the fabric backside.

Claims

1. An article comprising a core spun yarn, the core spun yarn comprising:

a) a hard fiber skin;

b) an elastic core fiber I comprising spandex providing stretch to the article; and

c) an elastic core fiber II that provides recovery to the article and is separate from elastic core fiber I, the elastic core fiber II comprising spandex;

wherein the elastic core fiber I and the elastic core fiber II have different elastic properties, and wherein the core spun yarn exhibits higher stretch and recovery than a single core spun yarn having the same spandex content.

2. The article of claim 1, wherein the elastic core fiber I and the elastic core fiber II have different deniers or different filaments.

3. The article of claim 1, wherein the elastic core fiber I and the elastic core fiber II have different drafts.

4. The article of claim 1, wherein the elastic core fiber I and the elastic core fiber II have different polymer compositions.

5. The article of claim 1, wherein at least one elastic core fiber comprises an elastomeric fiber having a denier of 10 to 450.

6. The article of claim 1, wherein at least one set of elastic core yarns is a pre-wrapped elastic yarn having a denier of 15 to 300.

7. The article of claim 6, wherein the pre-coated elastic yarn comprises a coating selected from the group consisting of: air-wrapped yarns, single-wrapped yarns, double-wrapped yarns, and combinations thereof.

8. The article of claim 6, wherein the pre-coated elastomeric yarn is a polyester and spandex air-coated yarn.

9. The article of claim 1, wherein at least one elastic core fiber comprises a non-elastomeric elastic fiber having a denier of 15 to 450 denier.

10. The article of claim 9 wherein said non-elastomeric elastic yarn is selected from filaments having a yarn recoverable stretch of greater than 20% as tested by ASTM D6720-07 method.

11. The article of claim 10 wherein said non-elastomeric elastic yarn comprises at least one fiber selected from the group consisting of: polyester, nylon, PTT fibers, PBT fibers, bicomponent fibers, and combinations thereof.

12. The article of claim 1, wherein the hard fiber skin is selected from the group consisting of: wool, flax, silk, polyester, nylon, olefins, cotton, and combinations thereof.

13. An article comprising a woven fabric having warp yarns and weft yarns, wherein at least one of the warp yarns and the weft yarns comprises a core spun yarn comprising:

a) a hard fiber skin;

b) an elastic core fiber I comprising spandex, providing stretch to the fabric; and

c) an elastic core fiber II providing recovery to the fabric and separate from elastic core fiber I, the elastic core fiber II comprising spandex;

14. The article of claim 13, wherein the fabric has a stretch in the weft direction of between 10% and 45%.

15. The article of claim 13, wherein the fabric comprises a garment.

16. A method of making an article comprising a woven fabric having warp yarns and weft yarns, the warp yarns or the weft yarns or both the warp and weft yarns having a core spun yarn, wherein the core spun yarn comprises:

a) a hard fiber skin;

17. A stretch fabric comprising a core spun yarn, the core spun yarn comprising:

a) a hard fiber skin;

18. The stretch fabric of claim 17, wherein the fabric is a woven fabric, or a warp knit fabric, or a circular knit fabric.