JP7015273B2 - Stretch yarns and fabrics with multiple elastic yarns - Google Patents

Description

The present invention relates to the manufacture of stretch composite yarns and fabrics. The present invention relates specifically to fabrics and methods that include two sets of elastic core fibers in a single yarn.

Stretch fabrics using elastic composite yarns have been on the market for many years. Fabric and garment manufacturers are well aware of how to make fabrics with appropriate quality parameters to achieve consumer acceptable fabrics. In the fabrics currently on the market, there is only one type of elastic fiber system inside the yarn and the fabric. One type of elastic fiber serves the dual function of extensibility and resilience. It is difficult to obtain fabrics that are stretchable, highly resilient and have a low degree of shrinkage.

Ease of stretching is one important feature of comfortable clothing. In the case of comfortable garments, the fabric can be easily stretched as the garments are wrapped around the human body and moved. The pressure on the wearer's body due to clothing is low. The garment can be cut to achieve a more streamlined appearance, while maintaining the comfort of the wearer in motion, and can be better suited to the shape of the body. Such performance can be achieved by reducing the tensile modulus of the fabric by minimizing the resistance of the garment to the body's demands during operation.

However, a typical quality problem with fabrics with low tensile modulus is that when the fabric is overstretched in parts of the body, such as the knees, hips and waist, the fabric has a high level of stretch, especially for fabrics. It cannot be quickly restored to its original size and shape. In most cases, the smaller the modulus of tensile modulus, the lower the resilience of the fabric. Consumers face the problem of sagging and sagging when worn for extended periods of time.

On the other hand, in order to obtain a fabric having good resilience, it is necessary to add a shrinkage force in the fabric. Higher content or stronger elastic fibers can be added to the fabric. However, such a fabric has a high extension modulus and a high tightening force. Consumers are dissatisfied with the high pressure of clothing and the unpleasant tightening during wearing and operation. In addition, the fabric lacks dimensional stability. The heat set is a necessary process for controlling the shrinkage of the cloth. The comfort and freedom of movement of the garment is impaired by the shape retention and recovery function of the fabric. Fabrics with stretchability, high resilience and low degree of shrinkage are still desired.

For many years, composite elastic yarns have been well known. For example, US Pat. Nos. 4,470,250, 4998403, 7134265, 6848151 facilitate acceptable processing for knitting or weaving and are used for a variety of end-use fabrics. Elastomer fibers such as spandex have been covered with relatively non-elastic fibers in order to provide elastic composite yarns with acceptable characteristics. In U.S. Patent Application Publication No. 2008/0268734 (A1) and US2008 / 0318485A1, rigid filaments are used with elastic filaments as the core in the core span yarn.

Therefore, it is necessary to produce stretch woven fabrics that are easy to stretch, easy to process, low shrinkage, easy to make garments, and have excellent resilience and low residual elongation (growth).

One aspect includes a method for making a composite yarn having two sets of different elastic core fibers called a double elastic composite yarn. Further included are this double elastic composite yarn, as well as stretch fabrics and garments made from this yarn.

According to the first embodiment of the method, two sets of elastic fibers having different properties and hard fibers are covered together to form a composite yarn, where two sets of elastic fibers are formed. Is stretched to different draft ratios to the original length during the yarn covering step. Elastic fibers may be bare spandex yarns from 11 to 560 dtex and rigid fibers may be from 10 to 900 dtex counts. An example of a suitable rigid yarn is cotton. Elastic core fibers I and elastic core fibers II are independently selected from elastomeric or non-elastomeric fibers.

According to the second embodiment of the method, two sets of elastic fibers (elastic core fibers I and elastic core fibers II) having different properties are covered together with the hard fibers to form a composite yarn. So, the two sets of elastic fibers have different polymer compositions and different stress-strain behaviors. Elastic fibers may be bare spandex yarns from 11 to 560 dtex and rigid fibers may be from 10 to 900 dtex counts. An example of a suitable rigid yarn is cotton.

According to a third embodiment of the method, two sets of different elastic core fibers (elastic core fibers I and elastic core fibers II) and the rigid fibers are covered together to form a composite yarn, where the elastic core fibers I and the elastic core fibers II are covered together to form a composite yarn. At least one set of elastic core fibers is a pre-covered elastic yarn. The other set of elastic core yarns may be bare spandex yarns or covered elastic yarns. The denier value of the bare spandex yarn is from 11 to 560 dtex, and the count of the hard fiber is from 10 to 900 dtex. An example of a suitable rigid yarn is cotton.

According to a fourth embodiment of the method, two sets of different elastic core fibers and rigid fibers are covered together to form a composite yarn, where at least one elastic core fiber is elastomer-free. (No-elastomeric) stretch fiber. The other set of elastic core yarns may be bare elastomeric yarns, such as spandex. The denier value of the bare spandex yarn is from 11 to 560 dtex, and the count of the hard fiber is from 10 to 900 dtex. An example of a suitable rigid yarn is cotton.

Fabrics are made by using double elastic yarns produced by one of these alternative methods. The double elastic yarn is used in at least one direction of the fabric. Any form of fabric may be used, including woven fabrics, round knits, warp knits and narrow fabrics. Further processing may include refining, bleaching, dyeing, drying, sanforizing, fluffing, degluing, mercerizing, and any combination of such steps. The stretched fabric produced can form on garments.

The following drawings will be referred to in detail. In these drawings, the same numbers refer to the same components.

It is a figure of the core span yarn which has two kinds of elastic cores. FIG. 3 is a schematic explanatory view of a core spinning device equipped with two draft machines used for two types of bare elastic fibers. FIG. 6 is a schematic explanatory view of a core spinning apparatus equipped with two draft machines having a weighted roll. FIG. 3 is a schematic explanatory view of a core spinning apparatus equipped with two draft machines used for one type of bare elastic fiber and one type of covered elastic yarn.

Elastomer fibers are often used to impart stretchability and elastic resilience to woven fabrics and garments. An "elastomer fiber" is either a continuous filament (which may be a multifilament in which several are combined into one) or multiple filaments without the use of a diluent, with crimping. The breaking elongation exceeds 100% regardless of. Elastomer fibers are (1) stretched to twice their length, (2) held for 1 minute and then (3) released, 1.5 times their original length within 1 minute of being released. Back to less than. As used herein, "elastomer fiber" means at least one elastomer fiber or filament. Such elastomeric fibers include, but are not limited to, rubber filaments, biconstituent filaments and elastesters, rustols and spandex.

"Spandex" is an artificial filament in which the filament forming material is a long chain synthetic polymer containing at least 85% by weight of segmented polyurethane.

An "elast ester" is an artificial filament in which the fiber forming material consists of a long chain synthetic polymer containing at least 50% by weight of an aliphatic polyether and at least 35% by weight of polyester.

A "two-element filament" is a continuous filament or fiber containing at least two polymers bonded to each other along the length of the filament, where each polymer belongs to a different general category, eg, the core is an elastomer. Is a polyether amide, the sheath is a continuous filament or fiber, such as a polyamide with a robe or wing.

A "lastol" is a fiber of a crosslinked synthetic polymer with low but significant crystallinity, consisting of at least 95 weight percent ethylene and at least one other olefin unit. The fibers are elastic and substantially heat resistant.

A "polyester two-component filament" is a continuous filament containing a pair of polyesters that are closely adhered to each other along the length direction of the fiber, in which the cross-sections of the fibers are, for example, adjacent eccentricities. It means a continuous filament having a sheath-core structure, or any other suitable cross section capable of producing useful crimps. Fabrics made of this filament, such as Elastellal-p, PTT / PET binary fibers, etc., have excellent recovery characteristics.

"Elastomer-free elastic fiber" means a stretch filament that does not contain an elastomer fiber. However, the recoverable stretch of such threads, such as textured PPT stretch filaments, textured PET stretch filaments, binary stretch filament fibers or PBT stretch filaments, is ASTM. Must be higher than 20% when tested by the method of D6720.

A "precovered elastic yarn" is one that is surrounded by a rigid yarn, twisted with a rigid yarn, or mixed with a rigid yarn prior to the corespun process. Precovered elastic yarns containing elastomeric fibers and rigid yarns are also referred to herein as "precovered yarns". Covering with rigid yarns functions to protect the elastomeric fibers from abrasion in the process of textile products. Such wear can lead to breakage of the elastomeric fibers, resulting process interruptions and undesired fabric non-uniformity. In addition, this covering helps stabilize the elastic behavior of the elastomeric fibers, so that the stretch of the precovered elastic yarn in the process of textile products is more uniform than the stretch expected when bare elastomeric fibers are used. Can be controlled. Precovered yarn can also increase the tensile modulus of yarn and fabric, helping to improve the resilience and dimensional stability of the fabric.

Pre-covered yarns include (a) a single winding of a hard yarn around an elastomer fiber, (b) a double winding of a hard yarn around an elastomer fiber, and (c) a continuous covering of the elastomer fiber with a staple fiber (c). That is, core span or core spinning), which is subsequently twisted during winding, (d) elastomer and rigid yarn mixed and entangled with an air jet, and (e) elastomer fiber and rigid yarn. Some are twisted together.

A "double elastic composite yarn" is a composite yarn containing two sets of elastic core fibers per yarn and covered with a sheath which is a rigid staple fiber. Throughout this specification, the term "double elastic yarn" is used interchangeably.

The stretch fabric of some embodiments contains a double elastic core span yarn in the warp direction. In some embodiments, fabrics with unexpectedly high recovery properties have been achieved, especially in the case of highly stretchable fabrics. This was accomplished by the use of core span yarn containing two different elastic fibers with different elongation properties. Those skilled in the art will recognize that the fabric may contain such corespun yarns with double elastic fibers in the weft direction if warp stretch is desired.

As shown in FIG. 1, the double elastic yarn 8 according to the present invention always includes two types of elastic filament cores, that is, elastic core I (4 in FIG. 1) and elastic core II (6 in FIG. 1). Will be. The elastic core filament is preferably surrounded by a fiber sheath 2 containing spun staple fibers over its entire length.

An embodiment of a typical core spinning device 40 is shown in FIG. The machine is fitted with two separate fiber draft machines 46 and 64. During core spinning, the elastic core filaments I 48 and elastic core filaments II 60 are separately mounted on feed rolls 46 and 64 and combined with the rigid yarn to form a composite core spun yarn. The core elastic filaments derived from the tube 48 and tuber 60 are unwound in the directions of arrows 50 and 62 by the action of the feed rollers 46 and 64 driven in the positive direction. The feed rollers 46 and 64 act as cradle for the tubes 48 and 60, feeding the elastic fibers threads 52 and 66 at a predetermined speed.

The rigid fiber or thread 44 is unwound from the tube 54 and merges with the elastic core filaments 52 and 66 on a set of front rollers 42. The combined elastic core filaments 52 and 66 and the rigid fiber 44 are core-spun together by the spinning machine 56.

The elastic core filament I 52 and the elastic core filament II 66 enter the front roller 42 after being stretched (drafted). The elastic filament is stretched due to the speed difference between the feed roller 46 or 64 and the front roller 42. The feed speed of the front rollers 42 is faster than the speeds of the feed rollers 46 and 64. By adjusting the speed of the feed rollers 46 and 64, the desired draft ratio or stretching ratio can be obtained.

The draw ratio is usually from × 1.01 times to × 5.0 times (from 1.01 × to 5.0 ×) as compared with the fiber in the unstretched state. If the draw ratio is too low, it results in poor quality yarn with grin-throwh and un-centered elastic filaments. If the draw ratio is too high, the elastic filament breaks and core voids occur.

Another embodiment of a typical core spinning device 40 is shown in FIG. The elastic core I is a bare elastic filament 48 and the elastic core II 12 is a covered elastic thread. The elastic core II derived from the tube 12 is unwound in the direction of the arrow 62 by the action of the feed roller 64 driven in the positive direction. The weighted roll 66 functions to maintain stable contact between the elastic core II and the feed roller 64 and feed the elastic core II thread 68 at a predetermined speed. The other components of FIG. 3 are as described for FIG.

Another embodiment of a typical core spinning device 40 is shown in FIG. The elastic core I is a bare elastic filament 48 and the elastic core II 12 is a covered elastic thread. The elastic core II from the tube 12 exits the end and then passes through the tension control means and the guide bar. The tensioning means functions to keep the tension of the yarn stable at a predetermined level. The draw ratio of the bare elastic fiber is usually from × 1.01 times to × 5.0 times (from 1.01 × to 5.0 ×) as compared with the fiber in the unstretched state. The other components of FIG. 4 are as described for FIG.

According to some embodiments of the method, two elastic fibers having different properties and a rigid fiber are covered together to form a composite yarn, in which the two elastic fibers are the yarn. During the covering process of, it is stretched to different draft ratios to its original length. The draft ratio of the two types of elastic fibers can be selected from the draft ratio × 1.01 times to × 5.0 times. For two core elastic fibers with different denier values or different filament numbers, the draw ratios of elastic core I and elastic core II may differ from each other, depending on the requirements of the elastic fiber performance and fabric quality. Often, one core is more highly drafted to provide higher stretch performance, and the other core is more less stretched to impart low shrinkage and high resilience to the fabric.

In traditional fabrics, if the heat setting is not used to "set" the spandex, the fabric may have a high shrinkage rate, excessive fabric weight and excessive elongation, which is disgusting to consumers. May have experience. Excessive shrinkage during the fabric finishing process can cause crease marks on the fabric surface during processing and home cleaning. The creases thus formed are often very difficult to remove by ironing.

By using a low draft ratio on one of the elastic core fibers, the method avoids the hot heat setting step. This new method can reduce thermal damage to certain fibers (ie cotton) and thus improve the feel of the finished fabric. The fabric of some embodiments may be prepared without the heat setting step, including the case of tailoring the fabric to garment. As a further benefit, this new method can use heat-sensitive rigid yarns to make shirt fabrics, elastic fabrics, and thus increase the likelihood of producing a wide variety of improved products. can. In addition, shorter methods bring productivity benefits to fabric manufacturers.

Unexpectedly, core span yarns with two different elastic core fibers were found to be more extensible and resilient than core span yarns made from a single core elastic filament at the same denier value. It was issued. For example, a core spanyan with two cores, a 30d / 3 filament spandex and a 40D / 4 filament spandex, is more resilient than a core span made from a single core of 70D / 5 filaments using the same draft ratio. Is high. That is, spandex of the same content can be used to make core spanyans with higher extensibility and higher resilience.

Two types of elastic fibers having different properties can be used, and these elastic fibers are covered together with a rigid fiber sheath to form a composite yarn, in which case the two types of elastic fibers are used. May have different polymer compositions and different stress-strain behaviors. One example is two types of spandex fibers with different heat set efficiencies, for example, normal LYCRA® spandex fiber T162C and easy set LYCRA® fiber T562B, together in one core spanyan. Is to use. The fabric can be heat-set at a temperature higher than the heat-setting temperature of the EasySet LYCRA® fibers but lower than the heat-setting temperature of the normal LYCRA® fibers. That is, the fabric is only subject to a partial heat set that keeps the fabric shrinkage tolerable while maintaining good stretchability and residual elongation.

Another example is a core span containing an elastic core I with a high tensile modulus and an elastic core II with a low tensile modulus. The elastic core I imparts high resilience and low residual elongation to the fabric, while the elastic core II with a low modulus provides the fabric with ease of stretch, lower shrinkage, resulting in high stretchability, high. The fabric has holding power and high dimensional stability. Elastic fibers with different chemical compositions, such as polyolefin elastic fibers rustol and spandex, can also be combined together in a single core span yarn. While spandex fibers provide high resilience, lastol fibers contribute to good heat resistance and lower shrinkage.

The combination of the elastic core I and the elastic core II may be a bare elastic fiber + a bare elastic fiber, a bare elastic fiber + a covered elastic thread, or a covered elastic thread + a covered elastic thread. Bare elastic fibers can range from about 11 dtex to about 444 dtex (from about 10 D to about 400 D at denier values), for example from 11 dtex to about 180 dtex (from 10 D to about 162 D at denier values).

Pre-covered elastic yarns include one in which a rigid yarn is wound in a single layer around an elastomer fiber, one in which a rigid yarn is doublely wound around an elastomer fiber, and one in which the elastomer fiber is continuously covered with staple fiber (that is, core spinning). There are various types such as those that are twisted at the time of winding, those that mix an elastomer and a hard yarn with an air jet and entangle them, and those that twist an elastomer fiber and a hard yarn. A preferred precovered elastic yarn is a spandex air jet covered yarn with textured polyester and nylon filaments, such as an air jet covered yarn with 40D or 70D spandex and polyester from 50D to 150D. Pre-covered elastic yarns are machined and then subjected to the corespun yarn process.

The precovered elastic yarn can be present in any desired amount, eg, from about 5 to about 35 weight percent (%) of the total weight of the double elastic yarn. The linear density of the covered yarn ranges from about 15 denier (16.5 dtex) to about 900 denier (990 dtex), for example from about 30 denier to 300 denier (33 dtex to 330 dtex). Thread denier ratio (rat) of the total of pre-covered yarn and double elastic yarn
When the io of yarn denier) is lower than 35%, there is virtually no peeling of the fabric. After the finishing process, the two elastic core fibers contained in the covered yarn are invisible and untouchable.

The denier value of bare elastic fibers (before covering to form a covered yarn) ranges from about 11 dtex to about 444 dtex (denier value from about 10 D to about 400 D), for example from 11 dtex to about 180 dtex. It may be (from 10D to about 162D in denier value). During the pre-covering process, the elastic fibers are drafted between the original lengths of 1.1x and 6x. In precovering, the elastic fibers are precovered with one or more rigid yarns having a denier value of 10 to 600 denier.

Another combination of elastic core fibers I and elastic core fibers II may be one set of bare elastic fibers + another set of elastomer-free elastic fibers. Elastomer-free elastic fibers may be textured PET stretch filaments, textured PPT stretch filaments, binary fibers or PBT stretch fibers. It is surprising to find that the performance of core span yarns and fabrics changes dramatically when elastomer-free elastic fibers with a recoverable elongation of more than 20% are used as one of the elastic core fibers. there were. The fabric has high extensibility and high resilience. The linear density of the elastomer-free elastic fibers may range from about 15 denier (16.5 dtex) to about 450 denier (495 dtex), for example from about 30 denier to 150 denier (33 dtex to 165 dtex). If the denier value is too high, the fabric can have considerable peeling.

The content of elastomer fibers in the double elastic core span yarn is from about 0.1% to about 20%, for example from about 0.5% to about 15% and even from about 5% to the weight of the yarn. Between about 10%. The content of the elastomeric fibers in the fabric may be from about 0.01% by weight to about 10% by weight, for example from about 0.5% to about 5%, based on the total weight of the fabric.

The staple sheath fiber in the double elastic yarn may be a natural fiber such as cotton, wool or linen. Such staple fibers include single component poly (ethylene terephthalate) and poly (trimethylene terephthalate) fibers, polycaprolactum fibers, poly (hexamethylene adipamide) fibers, acrylic fibers, modacryl fibers, acetate fibers, and rayon fibers. , Artificial or synthetic staple fibers made of nylon, or combinations thereof.

Such double elastic yarns can be used to make stretch fabrics to which various weave patterns such as plain weave, poplin, twill weave, oxford, dobby, sateen, satin and combinations thereof can be applied. The fabric of some embodiments may have warp and / and warp and weft direction elongation from about 10% to about 45%. This fabric may shrink by about 15% or less after washing. This stretch woven fabric may have an excellent hand feel. Clothing may be tailored from the fabrics described herein.

The warp may be the same as or different from the warp. The fabric may be a weft stretch only or a bi-stretch, in which case it exhibits useful stretch and recovery properties 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 important in producing a satisfactory fabric. The fabric can be finished by a continuous range process and a post-dyeing jet process. The traditional equipment found in continuous finishing plants and post-dyeing plants is often suitable for processing. The usual series of finishing steps includes preparation, dyeing and finishing. For pretreatment and dyeing steps, such as singing, desizing, refining, bleaching, mercerizing and dyeing, the usual processing methods for elastic fabrics are usually sufficient.

Analysis method:
Recoverable stretch rate of yarn The recoverable stretch rate of the elastic fiber used in this example was measured as follows. Each yarn sample was skeined with a total denier value of 5000 +/- 5 (5550 dtex) using a skein frame at a tension of about 0.1 gpd (0.09 dN / tex). The skein was left at 70 ° F (+/- 2 ° F) (21 ° +/- 1 ° C) and 65% relative humidity (+/- 2%) for at least 16 hours. The skein is suspended substantially vertically from the stand, a 6 mg / den (5.4 mg / dtex) weight (eg, 30 grams for a 5550 dtex skein) is hung from the lower end of the skein, and the weighted skein is the equilibrium length. The length of the skein is set to 1 mm (within).
1 mm) measured and recorded as "C _b ". The 5.4 mg / dtex weight was left skeined for the duration of the test. Next, a weight of 1030 grams (206 mg / d, 185.4 mg / dtex) was suspended from the lower end of the skein, the length of the skein was measured in 1 mm increments and recorded as "L _b ".

The 1030 g weight was removed and then the skein was immersed in boiling water at 100 ° C. for 10 minutes, after which the skein was removed from the water and placed under the conditions as described above for 16 hours. This step is designed to simulate the relaxation process of a commercial fabric and is one way to improve the stretchability of the fabric. The length of the skein was measured as described above and the length was recorded as " _Ca ". _A 1030 gram weight was suspended from the skein again, the length of the skein was measured as described above and recorded as "La". The recoverable stretch rate (%) "CC _a " of the yarn after relaxation was calculated by the formula CC _{a =} 100 × (La −C _a ) / _La . The shrinkage ratio of the yarn was calculated by the formula Cs (%) = 100 × (L _b − _{La) / L b .}

Elongation (elongation rate) of woven fabric
The fabric is evaluated for stretch rate (%) when a specific load (ie, force) is applied in the stretch direction (one or more directions) of the fabric. Here, the stretch direction of the fabric is the direction of the composite yarn (that is, the weft, the warp, or the weft and the warp). Three samples measuring 60 cm x 6.5 cm were cut from the fabric. The longer dimension (60 cm) corresponds to the stretch direction. Partially loosen the sample and narrow the sample width to 5.0 cm. The samples were then placed under conditions of 20 ° C. +/- 2 ° C. and 65% +/- 2% relative humidity for at least 16 hours.

A first benchmark was set up over the width of each sample at a position 6.5 cm from the edge of the sample. A second benchmark was set up over the sample width at a position 50.0 cm from the first benchmark. The excess fabric from the second benchmark to the other end of the sample was used to form and sew a loop through which the metal pins could pass. The loop was then notched so that the weight could be attached to the metal pin.

The sample end on the side without the loop was clamped and fixed, and the fabric sample was hung vertically. A 17.8 Newton (N) weight (4LB) is attached to a metal pin through the hanging fabric loop to allow the fabric sample to be stretched by the weight. The sample was "exercised" by stretching with a weight for 3 seconds and then manually removing the force by lifting the weight. This cycle was performed 3 times. The weight was then allowed to hang freely, thereby stretching the fabric sample. The distance between the two benchmarks was measured in millimeters with the fabric loaded. Let this distance be ML. The original distance between the benchmarks (ie, the unstretched distance) was taken as the GL. The fabric elongation (%) for each individual sample was calculated as follows :
Elongation rate (%) (E%) = ((ML-GL) / GL) x 100
The results of the three growth rates were averaged and used as the final result.

Residual elongation of woven fabrics (unrecoverable extensibility)
When stretched, the fabric with no residual stretch is completely restored to its original length before stretching. However, typically, the stretch fabric does not fully recover and is slightly longer after a long stretch. This slight increase in length is called "residual elongation".

The fabric elongation test described above must be completed prior to the residual elongation test. Only the stretch direction of the fabric was tested. Two-way stretch fabrics were tested in both directions. Three samples, 55.0 cm x 6.0 cm each, were cut from the fabric. These were different samples than those used in the elongation test. The direction of 55.0 cm corresponds to the stretch direction. The sample was partially loosened and the sample width was narrowed to 5.0 cm. The sample was placed under the same temperature and humidity conditions as in the elongation test above. Two benchmarks, exactly 50 cm apart, were drawn across the width of the sample.

Using the known elongations (%) (E%) obtained in the elongation test, the length of the sample when this known elongation was 80% was calculated. this is,
E (length) at 80% = (E% / 100) x 0.80 x L
(In the formula, L is the original length between benchmarks (ie, 50.0 cm))
Calculated as. Both ends of the sample were clamped and the sample was stretched until the length between the benchmarks was equal to the L + E (length) calculated above. This stretched state was maintained for 30 minutes, after which the stretching force was released to allow the sample to hang freely and relax. After 60 minutes, the residual elongation rate (%),
Residual elongation rate (%) = (L2 × 100) / L
(In the formula, L2 was the increase in length between benchmarks in the sample after relaxation, and L was the original length between benchmarks). This residual elongation rate (%) was measured for each sample, and the results were averaged to determine the numerical value of the residual elongation.

Shrinkage of woven fabric The shrinkage of the fabric was measured after washing. First, the fabric was placed under the same temperature and humidity conditions as for the elongation test and the residual elongation test. Two samples (60 cm x 60 cm) were then cut from the fabric. Samples were taken at least 15 cm from the edge. The fabric sample was marked with a quadrangle with four sides of 40 cm x 40 cm.

The sample was washed in a washing machine containing the sample and a fabric for bulking. The total amount input to the washing machine was 2 kg of the air-dried material, and the ratio of the test sample to the washing material was at most half. The laundry was gently washed and dehydrated at a water temperature of 40 ° C. The amount of detergent used was from 1 g / l to 3 g / l depending on the hardness of water. Samples were placed on a flat surface and dried, then placed under conditions of 20 ° C +/- 2 ° C and 65% +/- 2% rhh relative humidity for 16 hours.

The shrinkage of the fabric sample was then measured in the warp and weft directions by measuring the distance between the markings. The shrinkage rate C% after washing is
C% = ((L1-L2) / L1) × 100
(In the formula, L1 was the original distance between markings (40 cm). L2 is the distance after drying). The results are averaged for the sample and reported in both the weft and warp directions. Negative shrinkages reflect swelling, which could occur in some cases due to the behavior of the rigid yarn.

Fabric Weight The woven fabric sample was obtained by punching with a die using a die having a diameter of 10 cm. The cut out woven fabric samples were weighed in grams. The "fabric weight" was then calculated as grams / square meter.

The following examples demonstrate the present invention and its potential use in the manufacture of various fabrics. The invention can be made into other different embodiments, some of which may be modified in various obvious respects without departing from the scope and spirit of the invention. Therefore, it should be perceived that this example is exemplary in nature and not limiting.

For each of the following denim fabric examples, 100% cotton open-ended (OE) span yarn or ring span was used as the warp. The denim fabric contained two types of yarns, an OE yarn of 7.0 Ne and an OE yarn of 8.5 Ne, in an irregular arrangement pattern. The yarn was indigo dyed in rope form prior to beaming. Then, this thread was glued to prepare a weaving beam. For bottom weight fabric, the warp is 20 Ne, 100% cotton ring span yarn. This thread was glued to prepare a weaving beam.

Table 1 lists four examples of core spun yarns with one traditional elastic core filament and innovative yarns containing two sets of elastic cores.

Several core span yarns with double elastic core fibers were used as wefts. A variety of elastic core fibers such as bare spandex, precovered polyester / LYCRA® spandex fibers, or precovered nylon / spandex yarns were used as in the core. Table 2 lists the materials and manufacturing methods used to make the core span yarn for each example. Table 3 shows a detailed outline of the fabric structure and performance for each fabric. Lycra® spandex is available from INVISTA, s. a. r. L. , Wichita, KS. For example, in the spandex heading column, 40D means 40 denier and 3.5x means Lycra® draft ratio (meaning machine draft) produced by the core spinning machine. In the column heading "Rigid Sheath Thread", 20'is the linear density of the span yarn as measured by the English Cotton Count System. The remaining items in Tables 1 and 2 are clearly labeled.

Subsequently, the core span yarns of each example in Table 2 were used to make stretch woven fabrics. Table 3 summarizes the yarns used in the fabric, the woven pattern, and the quality characteristics of the fabric. Below are some additional comments for each of the examples. Unless otherwise noted, fabrics were woven on Donier air jets or rapier looms. The speed of the loom was 500 picks / minute. The width of the fabric was about 76 inches when it was on the loom and about 72 inches when it was on the loom. This loom has twice the weaving beam capacity.

Each raw fabric in the example was finished with a jiggle dye machine. Each woven fabric is 3.0% by weight Lubit® 64 (Sybron).
Inc. ) Was used for pre-washing at 49 ° C. for 10 minutes. The fabric was then subjected to 6.0% by weight Synthyme® (Dooley Chemicals. LLC).
Inc. ) And 2.0 wt% Merpol® LFH (EI DuPont Co.) at 71 ° C. for 30 minutes, followed by 3.0 wt% Lubit® 64. , 0.5 wt% Merpol® LFH and 0.5 wt% trisodium phosphate at 82 ° C. for 30 minutes. Following the finishing of the fabric, the fabric was dried at 160 ° C. for 1 minute while being stretched on a tente frame.

Thread Example A: A typical core span yarn with one type of elastic core fiber.
This is not an innovative thread. This core spanyan is 16 Ne and has one 40d LYCRA® spandex fiber covered by a cotton sheath. The draft ratio of LYCRA® fibers is 3.5 × in the covering process. The cotton twist level TM is 18 twists per inch. The recoverable stretch rate of this yarn after boil-off is 17.71%.

Thread Example B: Core Span Yarn with Two Core Elastic Fibers This core span yarn is 16 Ne and has two sets of LYCRA® spandex fibers covered by a cotton sheath. The elastic core I fiber is 20D T162B, and the elastic core II fiber is also 20D T162B. The total denier value of the elastic fiber is 40 denier. The draft ratio of LYCRA® fibers is 3.5 × in the covering process. The cotton twist level TM is 18 twists per inch. Therefore, this corespun yarn has the same structure as yarn example A, such as count, LYCRA® fiber denier value and plying level, except that it has two sets of core elastic filaments instead of one corespun yarn. Have. The recoverable stretch rate of this yarn is 20.63%, which is 2.92% higher than that of sample A. This means that a yarn having a core consisting of two sets of filaments has a higher recoverable elongation rate than a yarn having a set of filament cores if the spandex content is the same. In this way, the innovative yarn can impart high stretchability and high resilience to the fabric using the same amount of elastic fibers.

Thread Example C: A typical core span yarn with one type of elastic core fiber.
This is not an innovative thread. This core spanyan is 16 Ne and has one 70d LYCRA® spandex fiber covered by a cotton sheath. The draft ratio of LYCRA® fibers is 3.8 × in the covering process. The cotton twist level TM is 18 twists per inch. The recoverable elongation rate after boiling off of this thread is 38.71%, and the shrinkage rate of the thread is 2.28.

Thread Example D: Core Span Yarn with Two Core Elastic Fibers This core span yarn is 16 Ne and has two sets of LYCRA® spandex fibers covered by a cotton sheath. The elastic core I fiber is 30D T162B and the elastic core II fiber is 40D T162B. The total denier value of the elastic fiber is 70 denier. The draft ratio of LYCRA® fibers is 3.8x for both in the covering process. The cotton twist level TM is 18 twists per inch. Therefore, this core span yarn has the same structure as yarn example C except that it has two sets of core elastic filaments instead of one set of core span yarns. This yarn recoverable stretch rate is 40.88%, which is 2.17 unit percent higher than the yarn sample C. This indicates that a yarn having a core consisting of two sets of filaments has a higher recoverable elongation rate than a yarn having a set of filament cores if the spandex content is the same. In this way, the innovative yarn can impart high stretchability and high resilience to the fabric using the same amount of elastic fibers.

Example 1
Typical stretch woven bottom weight fabric This is a comparative example not according to the present invention. The warp was a 40/2 Ne count ring span yarn. The warp was a core spandex of 20 Ne cotton and 40D Lycra®. The draft ratio of Lycra® is 3.5x. This warp was a typical stretch yarn used in typical stretch woven khaki fabrics. The 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 this finished fabric has weight (8.95 g / m ² ), elongation (37.6%), width (50.5 inches), warp and weft wash shrinkage (0.91%), and fabric. It shows that the residual elongation was (8.7%). From the data, it can be seen that the combination of the stretch yarn and the fabric structure increased the residual elongation rate of the fabric.

Example 2
Stretch fabric with double elastic fibers This sample had the same fabric structure as that of Example 1. The only difference is the 20s weft containing double core elastic fibers, i.e., 40d LYCRA® fibers with a draft ratio of 3.5x and 40d LYCRA® fibers with a draft ratio of 1.8x. It was to be used. The warp was 40/2 Ne ring-spun cotton. The speed of the loom was 56 picks per inch and 500 picks per minute. Table 3 summarizes the test results. Table 3 clearly shows that in this sample, the elongation rate is similar, but the residual elongation level of the fabric is reduced (6.4%). Therefore, by using two types of elastic core fibers having different draft ratios in the same yarn, the covered yarn and the fabric can acquire different characteristics. For example, the high draft ratio of elastic core I fibers gives the fabric high extensibility, while lowering the draft ratio of elastic core II fibers gives the fabric low residual elongation and high resilience but does not increase fabric shrinkage. In this way, fabrics with high extensibility, high resilience and low shrinkage can be produced.

Example 3
Stretch fabric containing double elastic fibers This sample had the same fabric structure as that of Example 1. The only difference is the use of core spandex, ie 40D T162B LYCRA® fiber with a draft ratio of 3.5x and 40d Easyset LYCRA® fiber with a draft ratio of 3.5x for the weft. Was that. The warp was a 20 Ne 100% cotton ring span yarn. A 3/1 twill weave pattern was applied. The finished fabric had a weight (9.19 g / m ² ), an elongation rate in the weft direction of 38.4.0%, and a residual elongation rate of 7.9%. This means that the Easyset LYCRA® fibers in Elastic Core II reduce the residual elongation of the fabric from 8.7% in Example 1 to 7.9% while maintaining the stretch level of the fabric. It is a clear indication.

The Easyset LYCRA® fiber can be heat-set at about 170 ° C., which is about 20 ° C. lower than the heat-setting temperature of the T162B LYCRA® fiber. Therefore, if the fabric is heat-set at a temperature between 170 ° C and 190 ° C, the fabric will be partially heat-set. Only Easyset LYCRA® fibers are set, not T162B. In this way, the shrinkage is kept below a certain level while the fabric retains better extensibility and resilience.

Example 4
The stretch fabric warp having spandex and elastic polyolefin fiber was an open-ended yarn in which 7.0 Ne count and 8.4 Ne count were mixed. The warps were indigo dyed prior to beaming. The warp and weft is a 16 Ne core span yarn with 40D T162B Lycra® spandex and 40D elastic polyolefin fibers. Lycra® fibers and elastic polyester fibers were drafted to 3.5x during the covering process. Table 3 lists the fabric characteristics. The fabric made from this yarn exhibited good cotton texture (hand), good elongation (47.8%) and good resilience (residual elongation 6.5%). All test results show that the combination of spandex and elastic polyolefin filament can produce good fabric extensibility and residual elongation. There is no peeling on the fabric. The elastic filament is invisible from the surface of the fabric or the back of the fabric.

Compared to spandex, elastic polyolefin or lastol fibers have lower resilience, but better heat resistance, better chemical resistance, lower fabric shrinkage, and a cotton sensation when touched. Touch feeling) is good. Fabrics containing both spandex and elastic polyolefins have better extensibility and good resilience, as well as better heat resistance, lower shrinkage and better chemical resistance, such as swimming pools and denim bleaching processes. Can be provided with chlorine resistance in.

Example 5
Stretch fabric containing spandex and covered elastic yarn This sample had the same fabric structure as in Example 1. The difference was the core span yarn in the weft direction. This core spandex contains one bare 40D LYCRA® fiber and one precovered elastic yarn (40D / 34f nylon / 40D Lycra® air covered yarn) in the core of the yarn. .. The draft ratio of the bare 40D LYCRA® fiber is 1.8x and the draft ratio of the LYCRA® fiber in the covered elastic yarn is 3.2x. This fabric used the same warp and structure as in Example 1. Further, the weaving and finishing steps were the same as in Example 1. Table 3 summarizes the test results. This sample had a good elongation rate (35.9%), a good wash shrinkage rate in the weft direction (0.65%), and a good residual elongation rate of the fabric (5.3%). You can see that. The appearance and feel of the fabric was excellent. The addition of precovered elastic yarn (40D / 34f nylon / 40D Lycra® fiber AJY yarn) significantly reduced the residual elongation of the fabric.

Example 6
Stretch fabric containing spandex and covered elastic yarn This sample had the same fabric structure as that of Example 5. The only difference was the draft ratio of bare 40D LYCRA® fibers in the covering process. The draft ratio of the bare LYCRA® fiber here was 3.5 ×, but in Example 5, it was 1.8 ×. The fabric weight was 8.96 OZ / yd ² , and the warp elongation was 37.8%. This fabric had a very low residual elongation in the warp (5.9%). This sample further confirms that the addition of additional elastic composite yarns can produce high performance stretch fabrics with low residual elongation. When the double elastic yarn is used, the residual elongation rate of the fabric becomes 5.9% from 8.7% in Example 1. Compared to Example 5, the increased draft ratio also increases weight and extensibility.

Example 7
Stretch denim containing spandex and covered elastic yarn This example had the same warp and fabric structure as in Example 4. The warp was an open-ended yarn in which 7.0 Ne count and 8.4 Ne count were mixed. The warps were indigo dyed prior to beaming. The warp and weft is a 16 Ne core spandex with 40D Lycra® spandex and 50D / 24f polyester / 40D LYCRA® fiber air jet covered yarn. The draft ratio of Lycra® is 3.5x for bare cores and 1.8x for composite cores. This sample is an innovative fiber. The loom speed was 500 picks per minute at a pick level of 44 picks per inch. Table 3 summarizes the test results. The test results show that the fabric after washing had a weight (12.80 OZ / Y ² ), a weft elongation rate of 35.3%, and a weft residual elongation rate of 3.5%.

Example 8
Stretch Denim Containing Spandex and Precovered Elastic Yarn This example is an example of a draft ratio of LYCRA® fibers in a covered elastic yarn (draft ratio 2.6 × in Example 8 vs. draft ratio 1. It had the same warp and the same fabric structure as in Example 7, except that it was 8 ×)). Table 3 summarizes the test results. It is clear that this sample had a better elongation rate compared to sample 7 (warp and weft, 40.4%).

Example 9
Stretch fabric with spandex and PBT stretch fibers This example had the same warp and fabric structure as Examples 7 and 8 except that 50D / 26f PBT stretch fibers were used as elastic core II fibers. .. This bare 50D / 26f PBT fiber has a recoverable elongation rate of 40.23% and a shrinkage rate of 3.44% when tested by the method of ASTM D6720. Lycra® fibers of elastic core I were drafted to 3.5x during the covering process. Table 3 lists the fabric characteristics.

The fabric made from this yarn exhibited good cotton texture, good elongation (40.7%) and good resilience (residual elongation 6.0%). All test results show that the combination of spandex and elastomer-free stretch filaments can produce good fabric extensibility and residual elongation. The fabric is not peeled and the elastic filaments are not visible from the surface of the fabric or the back of the fabric.

Claims (13)

a) Sheath and
b) Elastic core fiber I with spandex and
c) An article containing a core span yarn, which is an elastic core fiber II separate from the elastic core fiber I and includes an elastic core fiber II having spandex.
An article in which the elastic core fiber I and the elastic core fiber II have different elastic moduli while the spandex of the elastic core fiber I and the spandex of the elastic core fiber II have the same polymer composition. The article according to claim 1, wherein the elastic core fiber I and the elastic core fiber II have different denier values or different numbers of filaments. The article of claim 1, wherein at least one elastic core fiber comprises spandex fibers having a denier value from 10 denier to 450 denier. The article of claim 1, wherein at least one set of elastic core fibers is a covered elastic yarn having a denier value from 15 denier to 300 denier. The precovered elastic yarn has a covering portion selected from the group consisting of an air-covered yarn, a single wound yarn (singlewrapped yarn), a double wound yarn (doublewrapped yarn), and a combination thereof. The article according to claim 4, which is included. The article according to claim 4, wherein the pre-covered elastic yarn is an air-covered yarn of polyester and spandex. The article according to claim 1, wherein the sheath is selected from the group consisting of wool, linen, silk, polyester, nylon, olefin, cotton, and combinations thereof. An article containing a woven fabric having warps and wefts, wherein at least one of the warps and wefts is
a) Sheath and
b) Elastic core fiber I with spandex and
c) An elastic core fiber II that is separate from the elastic core fiber I and includes a core span yarn containing an elastic core fiber II having spandex , and the spandex and the elastic core fiber II possessed by the elastic core fiber I. An article in which the elastic core fiber I and the elastic core fiber II have different elastic ratios while having the same polymer composition as the spandex possessed by. The article of claim 8, wherein the fabric has an elongation in the warp direction between 10 and 45%. The article according to claim 8, wherein the fabric constitutes clothing. A method of making an article comprising a woven fabric having warps and wefts, wherein either the warps or the wefts or both the warps and the wefts have a corespun yarn.
a) Sheath and
b) Elastic core fiber I with spandex and
c) The elastic core fiber II, which is a separate body from the elastic core fiber I, includes the elastic core fiber II having spandex.
A method in which the elastic core fiber I and the elastic core fiber II have different elastic moduli while the spandex of the elastic core fiber I and the spandex of the elastic core fiber II have the same polymer composition. a) Sheath and
b) Elastic core fiber I with spandex and
c) A stretch fabric containing a core span yarn containing an elastic core fiber II having a spandex and an elastic core fiber II separate from the elastic core fiber I.
A stretch fabric in which the spandex of the elastic core fiber I and the spandex of the elastic core fiber II have the same polymer composition, but the elastic core fiber I and the elastic core fiber II have different elastic moduli . The stretch fabric according to claim 12, wherein the fabric is a woven fabric, a warp knitted fabric, or a circular knitted fabric.

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