KR100466768B1 - Stable Double Covered Elastic Yarn, Process for Making Same, and Fabric Comprising Same - Google Patents

Abstract

Provided are a double covered yarn based on spandex having a heat fixation rate of at least 50% and two seed yarns wound in the same direction, a method of making the same, and a fabric produced therefrom.

Description

Stable Double Covered Elastic Yarn, Process for Making Same, and Fabric Comprising Same}

Covered elastic yarn, such as a single covered yarn obtained by winding inelastic filament yarn or inelastic staple fibers around the core elastic yarn, and obtained by further winding a second inelastic filament yarn or inelastic staple fiber around the single covered yarn Double covered yarns are used for a variety of apparel applications. Recently, such covered elastic yarns have been used for stretch fabric applications that do not require significant stretchability.

Japanese Patent Publication No. 06-049736 (1994) discloses the use of elastic fabrics of elastic polyurethane fibers coated with multiple filament yarns having a weight ratio of multiple filament yarns to elastic fibers of 1 to 5. That is, the elastic fibers are 50% to about 80% by weight of the covered yarns. However, the problems of fluff, stability, and feel that occur when the fibers to be covered are in the form of staples are not solved in this document.

Moreover, typical stretch fabrics using conventional elastomeric polyurethane fibers have the disadvantage of having low wet heat settability and susceptibility to shrinking upon washing. In addition, the covered yarns exhibit instability such that the core yarns and sheath yarns move relative to each other so that the elastic yarns slide at the cut edges of the fabric and the core yarns penetrate the covering yarns. In addition, such spun yarns lead to the formation of fine hairs, resulting in fine hairy fabrics, or tend to curl in knitted products. To improve the high temperature wet stability, the heat set temperature can be increased but covered elastic yarns using pyrolytic fibers such as wool and acrylic staples as the seed yarns are wetted above 100 ° C. in dyeing and processing. Temperatures, or dry temperatures above 160 ° C., are unbearable at such temperatures because a soft hand may be lost or fabric strength may be reduced. There is still a need for stable covered elastic yarn.

Summary of the Invention

The double covered elastic yarn of the present invention is basically,

Spandex cores having spandex of 50% or more,

A first sheath yarn wound around the spandex to form a single covered yarn that does not exceed 40% of the total weight of the double covered yarn, and

It consists of a second sheath yarn wound around the single covered yarn, and the first and second sheath yarns are wound in the same direction.

The method for producing the double covered elastic yarn of the present invention

Preparing a spandex having a thermal fixation ratio of at least 50% from the spandex supply package,

Stretching the spandex to a range of about 100-250%,

Coating the stretched spandex with a first seed yarn to form a single covered yarn,

Coating the single covered yarn with a second sheath yarn wound in the same direction as the first sheath yarn to form a double covered yarn, wherein the single covered yarn is 40% by weight or less of the double covered yarn, and

Thermally fixing the double covered yarns.

The fabric of the present invention comprises the double covered yarn described above as the only warp yarn or weft yarn.

FIELD OF THE INVENTION The present invention relates to a stable double covered elastic yarn, a method of making the same, and a fabric comprising double covered elastic yarn, and more particularly to a spun yarn having a coordinated sheath twist orientation.

The term "spandex" as used herein refers to manufactured fibers wherein the fiber forming material is a long chain synthetic elastomer comprising at least 85% by weight of segmented polyurethane. About 20 to 166 decitex (about 18 to 150 denier) spandex is suitable for use in making the double covered yarns of the present invention.

The term "seed yarn" means a relatively inelastic spun yarn comprising continuous filaments, bundles of staple fibers or spun staple fibers, or both filaments and staple fibers. The term "first seed yarn" refers to a seed yarn wound around a spandex to form a single covered yarn. The term "second seed yarn" means a seed yarn wound around a single covered yarn to form a double covered yarn.

Suitable filament seed yarns include polyester, nylon, acrylic, rayon, acetate, silk and the like. Suitable staple fibers include synthetic fibers such as polyester, nylon, acrylic, rayon and acetate, and natural fibers such as cotton, wool, and the like, or combinations thereof. As the first seed yarn, continuous filaments, for example nylon filaments, are preferred. As the second seed yarn, wool and staple acrylic fibers are preferred.

The term "heat fixation" means that the spandex is elongated at an elongation of 100%, then heat treated in the stretched conditions, and is released from the stretch to a length longer than the original length. Thus, for example, when a 10 cm long spandex is stretched to 20 cm and then exposed to elevated temperatures and released 15 cm long after being released, the spandex has a 50% thermal fixation rate.

The term "fuzz" refers to the loose end of staple fibers expanded from double covered yarns, resulting in spun yarn with undesired fuzz that is difficult to knit or weave.

In order to obtain a stable double covered yarn of the present invention, the spun yarn is made to have a coordinated twist orientation of the first and second seed yarns. Spandex core fibers have a fixation rate of at least 50%, preferably at least 55%, at 100% elongation as measured by water immersion heat treatment at 100 ° C. for 60 minutes. In applications where the double covered yarns of the present invention are fixed in dry heat, the spandex has a fixed rate of at least 50% and preferably at least 55% after dry heat treatment at 140 ° C. for 1 minute when elongated at 100% elongation.

In the stable double covered yarns of the present invention, the first and second sheath yarns are wound in the same direction, ie both in the z-direction or the s-direction. In this environment, the yarn's apparent bulkiness (expansion) is small, and the sheath is tightened across the fuzz. As a result this results in fluff binding and reduces the number of excessively long hairs. In general, size does not apply to fabrics made of a single wool yarn such as warp yarns, so weaving is difficult if it is not possible to bond fine hairs to the yarn. Since the fine hair in the yarn of the present invention is bonded, it can be used without sizing as the only warp in the woven fabric. This is particularly useful for lightweight stretch woven fabrics for spring and summer garments, but in that case single covered yarns preferably have a relatively high common metric count, such as 1/40 ("single 40"). The double covered yarns of the present invention can also be used satisfactorily as the only weft yarn or as both warp and weft yarns.

In contrast, when the twist direction of the two sheath yarns is different, the twist of the first sheath yarn can be released during coating with the second sheath yarn, resulting in a bulky final spun yarn and increased fine hair, especially excessively long hair. have. In addition, different twisting directions can result in partial exposure of the first seed yarn to the surface.

The double covered yarns of the present invention comprise up to 40% by weight single covered yarns. Single covered yarns preferably do not exceed 30% by weight, in particular 25% by weight, of double covered yarns. If the single covered yarns exceed the above limit when compared to double covered yarns, the first seed yarns may appear on the yarn surface or the fabric surface, and the fabric then has the feel of the first seed yarns. In addition, if, for example, the second sheath yarn is wool, the number of wool fibers may be reduced in the final sheath, worsening the interlacing of the wool and causing excessively long fine hair, such products in particular warp or weft It becomes difficult to use as the only spinning yarn of.

In the spun yarn of the present invention, the spandex may be included in about 2 to 9% by weight, preferably about 2 to 5% by weight of the double covered yarn.

The double covered yarns of the present invention may be knitted or woven into a fabric and then heat set in the form of a package.

In the process of the invention, when measured at 100% elongation by water immersion at 100 ° C. for 60 minutes or dry heat treatment at 140 ° C. for 1 minute, a spandex having a fixed rate of at least 50%, preferably at least 55%, Taken from the supply package and stretched from about 100% to 250%. The stretched spandex is covered with the first seed yarn at about 300 to 800 revolutions per meter to form a single covered yarn.

The single covered yarn is then covered with a second sheath yarn wound in the same direction as the first seed yarn to form a double covered yarn comprising up to 40 wt% single covered yarn. The twist coefficient of the second sheath yarn may be about 80 to 130, preferably about 90 to 130 times / meter / (common number) ^1/2 . The single covered yarn preferably accounts for up to 30% by weight, more preferably up to 25% by weight of the double covered yarn.

The double covered yarns can then be heat fixed in the form of a package, or knitted or woven into a fabric and heat fixed to a fabric. Since spandex cannot shrink below the elongation to be coated, it is thermally fixed in the stretched state in the double covered yarn. Heat fixation may be performed with wet heat (steam or water) at 80 ° C. or higher or with dry heat at 110 ° C. or higher. Lower temperatures may be used if lower rates may be acceptable, but a higher rate of 50% or higher is preferred. However, the heat set temperature is preferably somewhat higher (eg about 20 ° C. higher) than the temperature at which the maximum heat shrinkage stress is exhibited by the spandex. Heat fixation at a temperature lower than the temperature at which the maximum heat shrinkage stress occurs will result in the yarns shrinking if a later temperature is applied above the heat fixation temperature. Preferred spandex used in the yarn of the invention has a maximum heat shrinkage stress at dry heat temperatures of about 110 ° C to 150 ° C.

In addition, the present invention is further described through the following examples, but the scope of the present invention is not limited thereto, and the scope of the present invention is defined in the appended claims.

<Experiment>

Heat shrinkage of spandex by using "Heat Stress Measurement Instrument KE-2S" (manufactured by Kanebo, Japan) and heating to dry heat starting from 27 to 28 ℃ at tension 0 The stress was measured. Measurements were performed with 10 strands of spandex.

The common count (km / kg) of the covered elastic yarn was calculated from the gram weight per 100 m of the spun yarn measured in length with a 1 m circumferential lap reel with a tension of 20 g per strand.

The number of fine hairs was measured by counting the fine hairs in 10m length of the double covered yarn.

The weaving capability of the yarns in the examples was measured by making plain weave products using Sulzer Ruti (Swiss Winters) injection looms operating at 400 rpm.

In all examples, the first sheath yarn was between nylon false twisted continuous filaments and the second sheath yarn was wound in the z-direction. After applying the second seed yarn, the double covered yarn was wound on bobbin and steam heat fixed on the bobbin at 85 ° C. for 30 minutes.

In all examples, the raw fabric is washed in 40 ° C. water, dried for 1 minute at 120 ° C. on a tenter frame, dyed for 45 minutes at 95 ° C. in a counterflow dyeing machine, and dried for 1 minute at 120 ° C. in a tenter frame. And processed for 45 minutes at 100 ° C. in a decatizer.

In the table, representative samples of the covered company of the present invention are shown in Arabic numerals, and comparative samples other than the present invention are shown in capital letters.

<Examples 1 and 2>

In Examples 1 and 2, the spandex was 20 decitex (18 denier) of Opelon T-178C (Japan) with a 410% elongation at break and an elongation at 1.19 dN / tex (1.35 g / d). Registered trademark of Polyurethane Elastics manufactured by Toray-Dupont Co., Ltd., Tokyo. The fixation rate after 60 minutes at 100 ° C. in water was 62%, and 56% after 1 minute at 140 ° C. under dry conditions. For 10 strands of spandex, the maximum heat shrinkage stress temperature was about 120 ° C to 140 ° C and the maximum heat shrinkage stress was 2.28g.

While covering with the first seed yarn in the z-direction, the spandex stretched 2.7 times (170% elongation). The second sheath yarn was a 1/40 common count wool, applied 569 times / meter and a twist factor of 90.

The fabric was woven with the double covered yarns of Examples 1 and 2 as the only yarn in the warp yarn. The weft yarn was 1/40 wool, the warp density was 28 strands / cm (72 strands / inch) and the weft density was 25 picks / cm (64 picks / inch).

<Example 3>

The spandex used in this example was 28 decitex (25 denier) T-178C Opelon (registered trademark). While covering with the first seed yarn in the z-direction, the spandex was stretched 2.8 times (180%). The second seed yarn was 1/32 acrylic staple and was applied at 522 times / meter and twist factor 92.

The yarn was woven into the yarn as the only yarn in the warp yarn. The weft yarn was a 1/32 common count acrylic staple, the warp density was 25 strands / cm (64 strands / inch), and the weft density was 22 picks / cm (57 picks / inch).

Comparative Example A

The double covered yarn of this example was prepared as in Example 2, but the first sheath yarn was applied in the s-direction such that the first and second sheath yarns had opposite twists.

<Comparative Example B>

The spandex used in this example is 22 decitex (20 denier) of T-127C Opelon (registered trademark) with a 560% elongation at break and an elongation at 1.06 dN / tex (1.20 g / d). Was. The fixed rate of this spandex was 21% after 60 minutes at 100 ° C. in water and 28% after 1 minute at 140 ° C. under dry conditions in a range different from the present invention. For 10 strands of spandex, the maximum heat shrinkage stress temperature was about 170 ° C to 180 ° C and the maximum heat shrinkage stress was 2.28g.

During coating with the first seed yarn, the spandex was stretched 2.8 times (180%). The second seed yarn was 1/40 wool and was applied at 569 times / meter and a twist factor of 90.

The fabric was woven with double covered elastic yarn as the only yarn in the warp yarn. The weft yarn was 1/40 common count wool, the warp density was 28 strands / cm (72 strands / inch), and the weft density was 25 picks / cm (64 picks / inch).

Comparative Example C

The spandex used in this example is 22 decitex (20 denier) of T-152C Opelon (registered trademark) with a 510% elongation at break and an elongation at 0.97dN / tex (1.10 g / d). Was. The fixed rate of this spandex was 33% after 60 minutes at 100 ° C. in water and 34% after 1 minute at 140 ° C. under dry conditions in a range different from the present invention. For ten strands of spandex, the maximum heat shrinkage stress temperature was about 160 ° C to 170 ° C and the maximum heat shrinkage stress was 2.89g.

During coating with the first seed yarn, the spandex was stretched 2.8 times (180%). The second sheath yarn was 1/40 wool, applied 569 times / meter and a twist factor of 90.

The fabric was woven with double covered elastic yarn as the only yarn in the warp yarn. The weft yarn was 1/40 common count wool, the warp density was 28 strands / cm (72 strands / inch), and the weft density was 25 picks / cm (64 picks / inch).

Table 1 shows the additional features of the composition and preparation of the spun yarn of the spun yarns of the present invention (Examples 1, 2 and 3) and comparative spun yarns (Examples A, B and C).

Example One 2 3 A B C First Seed Yarn Decitex 33 78 33 78 33 33 filament 6 24 6 24 6 6 Rotation / meter 700 400 700 400 700 700 Twisting direction Z Z Z S Z Z Single covered yarn as weight percent of double covered yarn 17.0 34.6 13.6 34.6 16.5 16.5

Weaving finish of the fabric with a length of 40 meters in length and 0.5 meters in width for X 10 or more cuts per roll, △ for 4 to 9 spun yarn cuts per roll, OO for weaving ability ratings for 3 or less cuts per roll Was given. If the shrinkage during dry cleaning did not exceed 4%, a dimensional stability of the fabric was given a rating of 00. Table 2 shows the weaving ability of the yarns, the dimensional stability of the woven products, and the number of yarns of varying lengths per 10 meters of double covered yarns.

Example One 2 3 A B C The number of fuzz ≥2mm, <4mm 231 437 261 428 220 240 ≥4mm, <7mm 54 129 61 148 65 50 7mm and above 4 18 10 27 8 6 Weaving ability 00 △ 00 △ 00 00 Fabric dimensional stability 00 00 00 00 x x

The data in the table above are stable double covered with a combination of low weight percent single covered yarns in spandex and double covered yarns (where the first and second seed yarns are applied in the same direction) with the required high% heat fixation rate. It is shown that yarns and stable fabrics made from such yarns can be achieved.

In Tables 1 and 2, the dimensional stability of the fabrics produced by the yarns of Examples 1-3 differs from that of the present invention through comparison of the yarns and fabrics of the invention (Examples 1-3) with those of the present invention and other comparative examples. It is superior to the dimensional stability of the fabric made of the yarn and it can be seen that the fabric of Comparative Example A exhibits an excessive number of medium to long fine hairs.

The comparison between Example A and Example 2 shows that when the twist directions in the first and second sheath yarns are the same, the number of excessively long fine hairs is small and the fine hair bonding is caused. In addition, in Example A, the nylon first sheath yarn was partially exposed to the surface of the spun yarn, and began to exhibit the feel of nylon.

Example 3 also shows that better doublecovered yarns are produced when the second seed yarns are acrylic staples.

Claims (10)

Basically, Spandex core with spandex having a thermal fixation rate of at least 50%, A first sheath yarn wound around the spandex to form a single covered yarn that does not exceed 40% of the total weight of the double covered yarn, and And a second sheath yarn wound around the single covered yarn, wherein the first and second sheath yarns are wound in the same direction. 2. The double covered elastic yarn of claim 1, wherein said spandex is about 2 to 9 weight percent of the total weight of the double covered yarn and the second seed yarn is wound with a twist factor of about 80 to 130. 3. The double covered elastic yarn of claim 2, wherein the single covered yarn is about 30% by weight or less of the total weight of the double covered yarn, the first seed yarn is nylon continuous filament, and the second seed yarn is wool or acrylic staple. 4. The double covered elastic yarn of claim 3 wherein the spandex is about 2-5% by weight of the total weight of the double covered yarn. Preparing a spandex having a thermal fixation ratio of at least 50% from the spandex supply package, Stretching the spandex to a range of about 100-250%, Coating the stretched spandex with a first seed yarn to form a single covered yarn, Coating the single covered yarn with a second sheath yarn wound in the same direction as the first sheath yarn to form a double covered yarn, wherein the single covered yarn is 40% by weight or less of the double covered yarn, and Heat-fixing the double covered yarns. The method of claim 5 wherein the double covered yarns are heat set in wet conditions at a temperature of about 80 ° C. or greater. The method of claim 5, wherein the double covered yarns are heat set in dry conditions at a temperature of about 110 ° C. or higher. 6. The method of claim 5, wherein the single covered yarn is 30 wt% or less of the double covered yarn, the first seed yarn is nylon continuous filament and the second seed yarn is wool or acrylic staple. A fabric comprising the double covered yarn of claim 1 as the sole warp. A fabric comprising the double covered yarn of claim 1 as the only weft yarn.