JP4123430B2 - Elastic composite yarn and method for producing the same - Google Patents

Description

【００２８】
【発明の効果】
本発明の複合糸は製織時はほとんど弾性がなく、張力による糸長差が生じにくい、取扱性、工程管理性に優れ、染色仕上げ工程ではじめて、弾性が発現する特徴を持つ、複合糸であり、塩素晒工程にも、アルカリ減量工程にも耐えうる優れた白度とソフトな触感が得られる弾性複合糸を提供することを可能とした。[0001]
BACKGROUND OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is suitable for use in shirts, blouse fabrics, stretch pant fabrics, uniform fabrics, etc., and has excellent chemical resistance and is excellent in providing fabrics with excellent process stability of woven and knitted fabrics. This invention relates to elastic composite yarn of cotton. More specifically, the present invention relates to an elastic composite yarn that exhibits stretchability for the first time after undergoing a heat treatment step after knitting in a state in which there is no stretchability in the knitting and weaving step, and a method for producing the same.
[0002]
[Prior art]
Elastic fibers using polyurethane (urea) elastic fibers (spandex) are widely used in the clothing field due to their excellent stretch properties, and in recent years, with the diversification of applications, various properties in addition to stretch properties For example, chemical resistance and heat resistance have been required.
However, spandex is generally inferior in chemical resistance compared to other materials due to its molecular structure, and has a problem of practical limitations.
[0003]
In order to solve these problems, attempts have been made to add additives to spandex, but this does not solve the essential characteristics of spandex, and sufficient effects have not been obtained. is there. In general, polyurethane elastic fiber has a high coefficient of friction, has many problems in the weaving and knitting process, has a poor texture as a clothing material, and has almost no dyeability, so it can be used in combination with other materials. Is almost. As the composite means, there are core-sheath type composite spun yarn in the case of short fibers, and in the case of filament yarn, there are means such as blending, twisting and covering.
[0004]
Especially for underwear and inner garments where moisture absorption performance is required, the counterpart material is cotton. As means for combining cotton fibers and elastic yarns, there are conventionally used methods of knitting and covering and means for covering. However, the core-sheath type composite spun yarn is excellent because it increases the coverage of the elastic yarn.
However, when cotton fibers and polyurethane elastic yarn are combined, there is a big problem. This is because polyurethane fibers cannot withstand the bleaching process, which is essential for finishing cotton fibers. Currently, chlorite exposure is avoided, and the conditions are limited to mild exposure conditions with hydrogen peroxide. Damage to the mechanical properties of the fibers is a problem and is limited to limited applications. In addition, the composite spun yarn of cotton fiber and polyurethane elastic yarn has a high elongation rate, so there is a large variation in the elongation rate due to tension variation during the preparation process and weaving. Inconsistent problems are likely to occur and process management is troublesome.
[0005]
In the case of a filament knitted fabric, there are means such as blending, twisting and covering when the filament yarn and the polyurethane elastic yarn are combined, but the tension during the preparation process and weaving is the same as in the case of the above composite spun yarn. The fluctuation of the elongation rate due to fluctuations is large, and unless strict tension control is performed, problems such as streak generation and unevenness are likely to occur, and process management is troublesome. Further, when the filament yarn is a polyester fiber, an alkali weight reduction is often performed. However, since the polyurethane elastic yarn has insufficient alkali resistance, there is also a problem that it is difficult to caulk to a weight reduction rate sufficient for creating a texture.
[0006]
[Problems to be solved by the invention]
The object of the present invention is to eliminate such a conventional problem and use an elastic composite yarn of polyolefin elastic fiber and non-elastic fiber to knit with an elastic composite yarn excellent in chemical resistance and resistant to chlorite bleaching and alkali weight loss processing. An object of the present invention is to provide an elastic composite yarn that is insensitive to process fluctuations at the time and has excellent process passability and a method for producing the same.
[0007]
[Means for Solving the Problems]
That is, the present invention has the following configuration.
1. Polyolefin elastic fiber and non-elastic fiber composite yarn, elongation rate before boiling water treatment is 5% or less, elongation rate after boiling water treatment is 20% or more, shrinkage rate during boiling water treatment is 8% or less An elastic composite yarn characterized by being.
2. 2. The elastic composite yarn according to the first aspect, wherein the mixed ratio of the polyolefin elastic fiber is 25% or less.
3. 2. The elastic composite yarn according to claim 1, wherein the polyolefin elastic fiber is a fiber obtained by crosslinking a substantially linear polyolefin having a branch.
4). 2. The elastic composite yarn according to claim 1, wherein the elastic composite yarn is a core-sheath type composite spun yarn, and the non-elastic fiber is made of cotton and arranged in the sheath portion.
5. 2. The elastic composite yarn according to claim 1, wherein the elastic composite yarn is mixed, twisted or covered, and the non-elastic fiber is a synthetic filament.
6). A non-elastic fiber roving is drafted between a front roller and a back roller, and a polyolefin elastic fiber drafted 2.5 to 5.0 times is supplied separately to the front roller, and the twist coefficient is 3.5 to 4 A method for producing an elastic composite yarn, which is wound around a spinning cup at a draft tension of the polyolefin elastic fiber or higher and twisted at 60 to 95 ° C. while twisting at .5.
7). The polyolefin elastic fiber is supplied while drafting 2.5 to 5.0 times, and the non-elastic fiber is wound at 500 to 1200 T / m in the draft region and wound up without loosening. A method for producing an elastic composite yarn, wherein the heat and humidity are set at a temperature of ° C.
[0008]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that, even in view of the heat setting characteristics of polyolefin elastic fibers, it has been possible to achieve even a slight fluctuation in tension, which cannot be achieved with conventional elastic composite yarns including spandex. The present invention is able to ensure the quality, and withstands the chlorite bleaching process and the alkali weight loss process.
[0009]
The polyolefin elastic fiber referred to in the present invention is uniformly branched, and is subjected to a crosslinking treatment from the viewpoint of improving various physical properties such as heat resistance, preferably to a substantially linear olefin. Fiber.
Here, the olefin fiber which is uniformly branched and is substantially linear refers to a polymer obtained by polymerizing an olefin monomer, and the degree of branching of the polymer is uniform.
For example, low-density polyethylene copolymerized with α-olefin and elastic fiber described in JP-A-8-509530 are examples.
Examples of the crosslinking method include chemical crosslinking using a radical initiator, a coupling agent, and the like, and a method of crosslinking by irradiating energy rays.
In consideration of stability after becoming a product, crosslinking by irradiation with energy rays is preferable, but the present invention is not limited to these methods.
[0010]
The elongation characteristics of the elastic composite yarn are important. The elongation before the boiling water treatment is 5% or less, preferably 1 to 3%. If it exceeds 5%, when used for wefts, there arises a problem that the width fluctuates due to fluctuations in tension at the time of weft driving, which makes it difficult to manage the fluctuations in the release tension and deteriorates the yield. When used for warp, it is necessary to manage the tension during aging. The same applies to a knitted fabric. In order to satisfy this elongation rate, it is important to perform wet heat setting after the combination, and the wet heat temperature is suitably from 60 ° C to 95 ° C. A set time of 15 minutes or more is sufficient.
Below 60 ° C, the setting effect is small. In the case of composite spun yarn and twisted yarn, the strain set of the fiber is insufficient and torque remains, causing snare and poor processability. If the temperature exceeds 95 ° C., the recovery of elasticity described later is impaired, which is not preferable. In general, this wet heat setting is performed in a pressure cooker in which air is extracted by decompression and then steam is supplied in order to eliminate the setting difference between the inner and outer layers. Although it is desirable that the elongation rate is low, a breaking elongation of 3% or more is necessary for maintaining the weaving property.
[0011]
However, more importantly, the elasticity is restored at a temperature equal to or higher than the wet heat set, and the elongation after the boiling water treatment is 20% or more, preferably 30 to 100%. If it is less than 20%, the elongation property as an elastic yarn is insufficient and sufficient stretchability cannot be imparted, which is not satisfactory. In particular, since the elastic recovery force is not so large, when elastic recovery is performed in a state where the cloth or the like has a restraining force, consideration must be given so as to provide a sufficient fringing effect.
[0012]
The shrinkage ratio of the elastic composite yarn during boiling water treatment is desirably 8% or less. If it exceeds 8%, the density of the knitted fabric increases and becomes hard. In order to avoid this, it is not preferable to reduce the density of the green machine because there are problems with the diameter of the knitting machine and the wrinkling width. The boiling water shrinkage of the composite elastic yarn is determined by the boiling water shrinkage of the non-elastic yarn, and this characteristic can be achieved by using fibers of 8% or less. More preferably, it is 5 to 8%.
[0013]
The mixing ratio of the cross-linked polyolefin fiber in the composite yarn is preferably 25% or less, and if it exceeds this, the strength of the composite yarn becomes insufficient, causing problems in the knitting process. Further, since the cross-linked polyolefin fiber does not have any dyeing ability, if the mixing ratio exceeds 25%, it is likely to cause unevenness when dyeing in a dark color. However, even if it is too thin, the bullet performance is insufficient and the purpose cannot be achieved. Therefore, it is preferably 5% to 25%. In order to reduce the mixing ratio, it can be achieved by making the composite yarn thicker or making the cross-linked polyolefin fiber thinner. However, the thickness of the composite yarn is limited by the application, and the cross-linked polyolefin fiber should be made thinner. Makes the economy worse and 5% is the limit. Further, if it is less than 5%, the recovery performance at the time of elongation is lowered, which is not preferable.
[0014]
One of the present inventions is a composite spun yarn, and it is preferable to use a polyolefin elastic fiber for the core and a cotton fiber for the sheath. The polyolefin elastic fiber can be temporarily set at a low temperature, and is excellent in the property of recovering elasticity at a temperature higher than the temporary set and excellent in chemical resistance. The sheath fiber is preferably a cotton fiber in order to maintain the moisture absorption characteristics required by the application. However, when there is a strong demand for easiness of drying during washing and anti-mold properties, the sheath fiber is less than 70% of the sheath fiber. Although some synthetic fiber staples such as polyester and nylon may be included, it is desirable that 30% or more is cotton fiber.
[0015]
The twist coefficient of the spun yarn is also important, and is preferably 3.5 or more and 4.5 or less. If it is less than 3.5, the core olefin fiber is a filament yarn, so it cannot withstand the ironing received in the weaving process or the preparation process, and peeling off occurs. Although it is allowed to be slightly lower for knit applications, it is preferably 3.5 or more for stable production. However, if the twist coefficient exceeds 4.5, not only the yarn becomes hard, but also the binding force of the fiber increases and the elastic recovery of the core fiber is impaired, which is not preferable. More preferably, it is 3.8 to 4.2. The twist coefficient is the in. Expressed by the value obtained by dividing the number of twists between them by √ cotton count.
[0016]
The draft ratio is an important factor that affects the elongation stress and elongation recovery characteristics of the composite yarn, and 2.5 to 5.0 is suitable. The draft ratio depends on the elongation of the elastic yarn, but the elongation of the elastic yarn is generally set to about 600% under production conditions, and 2.5 to 5.0 is suitable at this time. If it is less than 2.5, it becomes soft stretch, but the elongation percentage after boiling water treatment of the composite yarn is lowered, and the recoverability is also lowered, which is not preferable. On the other hand, if it exceeds 5.0, the yield at the time of producing the composite yarn decreases. More preferably, it is 3.0-4.5.
[0017]
Another invention is an elastic filament composite yarn. This refers to a composite yarn of polyolefin elastic fiber and synthetic filament yarn, and the synthetic filament refers to a filament such as a polyester filament, a polyamide filament, a polyolefin filament, rayon, cupra, acetate, acrylic, or promix. The filament of the child need not be thermoplastic, but may be false twisted yarn. As the composite method, mixed fiber, cross twist, false twist composite or covering can be used.
[0018]
In this case, the draft ratio of the polyolefin elastic fiber is the same as that of the composite spun yarn.
In the case of covering, there are a single cover and a double cover, but there is no particular limitation, and the number of wrinkles is suitably 500 T / m to 1200 T / m. When it is less than 500, the covering property is lowered, and there is a problem of unevenness. When it exceeds 1200, the constraint on the elastic yarn is increased, and the stretchability is lowered.
[0019]
【Example】
Hereinafter, although an Example demonstrates in detail, the range of this invention is not specifically limited. The characteristics defined in the present invention were measured by the following method.
[Elongation rate and shrinkage rate]
Using composite wrap reel with composite and wet heat set, use a lap reel with a circumference of 1m, make 8 skeins, apply a load of 0.1g / denier (denier of composite yarn), measure the skein length, mm). Next, the load was removed, and a new load of 0.001 g was applied to the denier of the core yarn (denier before the draft at the time of compounding), and the skein length was measured one minute later to obtain B (mm). Then wrap in gauze under no load, fix with clips, put in boiling water and treat for 30 minutes. After treatment, leave at room temperature for 1 hour or more, remove gauze, dry with hot air dryer at 40 ° C for 1 hour, scrape load of 0.1 g / denier again, measure skein length, mm). Next, the load was removed, and a new load of 0.001 g was applied to the denier of the core yarn (denier before the draft at the time of compounding), and the skein length was measured after 1 minute to obtain D (mm). The elongation rate and the shrinkage rate were obtained from the following equations.
Elongation rate before processing = {(A−B) / A} × 100 (%)
Elongation rate after treatment = {(C−D) / C} × 100 (%)
Shrinkage during processing = {(A−C) / A} × 100 (%)
[0020]
[Example 1]
A rough yarn made of cotton fibers having an average fiber length of 26 mm is drafted 48 times between the front roller and the back roller, and at the same time, a monofilament of cross-linked polyolefin fiber 44 dtex is drafted 3.5 times and supplied to the front roller. A twisted coefficient of 4.2 was wound around a fine spinning cup under a tension of 36 g to obtain a core-sheath type composite spun yarn of 40 cotton count. The mixture ratio of the crosslinked polyolefin fiber was 8.6%. The spun yarn was set for 15 minutes at 70 ° C. Table 1 shows the elongation and shrinkage of the yarn. A plain weaving woven fabric was obtained by arranging 40 counts of cotton yarn at a density of 90 yarns / in for warp and 70 yarns / in of the composite spun yarn for weft yarns. At this time, the weft was almost non-stretchable and could be handled in the same way as a normal cotton yarn, and it was not necessary to strictly control the tension. There was no occurrence of chatter. The fabric was subjected to fried hair, desizing, scouring, bleaching, mercerization, and sun holization processing in a normal continuous finishing process. Bleaching was carried out at 35 ° C. for 45 minutes with 35 g / liter of sodium chlorite (25%). The obtained fabric was a high-grade woven fabric having no width variation, high whiteness, soft tactile feel, and excellent stretchability and recoverability in the lateral direction.
[0021]
[Example 2]
A composite spun yarn was obtained in the same manner as in Example 1 except that the roving used for spinning was a polyester / cotton blend (65/35). Table 1 shows the properties of the raw yarn after the carrier set. The obtained woven fabric was slightly hard, but was suitable for men's shirting, having a wash and wear property, an anti-mold property, a stretch property and a high recovery property.
[0022]
[Example 3]
Cross-linked polyolefin fiber 44 decitex monofilament is drafted 3.5 times, polyester one-stage false twisted yarn is wound with S twist, wound at 1,000 T / m, wound in a damp heat-resistant bobbin in the draft state I took it. The yarn was set at 80 ° C. for 30 minutes, and then the weft yarn and the warp yarn were arranged with ester different shrinkage mixed yarn to make a woven fabric. Table 1 shows the properties of the raw yarn after the carrier set. The weft was not stretchable in the weaving process and could be handled in the same way as a normal inelastic yarn. There was no variation in the width of the fabric, and 25% alkali weight reduction processing was also performed, but there were no particular problems such as strength, discoloration, and extensibility.
[0023]
[Comparative Example 1]
A woven fabric was obtained in the same manner as in Example 1 except that the elastic yarn supplied at the time of composite spinning was polyurethane elastic yarn (Toyobo Espa Type 765) 44 dtex. The fabric had a width variation of 1 to 2 cm in the longitudinal direction, and extreme yellowing occurred in the bleaching process, making the fabric unusable. In addition, the strength of the elastic yarn was greatly reduced, and there was a problem in durability.
[0024]
[Comparative Example 2]
A woven fabric was obtained in the same manner as in Example 1 except that the carrier was not set after spinning. When using a shuttle loom when weaving the same fabric, the weaving width fluctuates greatly, and weaving machines with a uniform weaving width cannot be obtained unless weaving machines supply weft with constant tension such as rapier looms and jet looms. There was a need. Moreover, although it was partially at the time of weaving, chattering occurred and defects of the fabric were observed.
[0025]
[Comparative Example 3]
A fabric was obtained in the same manner as in Example 3 except that the elastic yarn was Lycra 127c44 dtex.
Table 1 shows the elongation characteristics of the elastic yarn. The resulting fabric had insufficient weft tear strength and was difficult to withstand practical use. In addition, the width of the green machine fluctuated if wefts were not set sufficiently and weft tension was not sufficiently controlled during weaving.
[0026]
[Comparative Example 4]
A fabric was obtained in the same manner as in Example 3 except that the elastic yarn was a melt-type polyester-based polyurethane elastic yarn (Toyobo Espa M) 44 dtex and the carrier setting conditions were 120 ° C. × 60 minutes.
Table 1 shows the elongation characteristics of the elastic yarn. The fabric was relaxed, and the fabric after the dyeing process was only a fabric with poor elasticity. In addition, it has no alkali resistance and no commercial property.
[0027]
[Table 1]

[0028]
【The invention's effect】
The composite yarn according to the present invention is a composite yarn that has almost no elasticity during weaving, is unlikely to cause a difference in yarn length due to tension, has excellent handleability and process controllability, and exhibits elasticity only in the dyeing finishing process. It has become possible to provide an elastic composite yarn that has excellent whiteness and soft feel that can withstand both the chlorine exposure step and the alkali weight loss step.

Claims (6)

A composite yarn of a polyolefin elastic fiber and a non-elastic fiber, the mixing ratio of the polyolefin elastic fiber is 5 to 8.6%, the elongation rate before boiling water treatment is 5% or less, and the elongation rate after boiling water treatment is 5% or less. An elastic composite yarn characterized by having a shrinkage rate of 20% or more and boiling water treatment of 8% or less. The elastic composite yarn according to claim 1, wherein the polyolefin elastic fiber is a fiber obtained by crosslinking a substantially linear polyolefin having a branch. 2. The elastic composite yarn according to claim 1, wherein the elastic composite yarn is a core-sheath type composite spun yarn, and the non-elastic fiber is made of cotton and arranged in the sheath portion. 2. The elastic composite yarn according to claim 1, wherein the elastic composite yarn is mixed, twisted or covered, and the non-elastic fiber is a synthetic filament. A non-elastic fiber roving is drafted between a front roller and a back roller, and a polyolefin elastic fiber drafted 2.5 to 5.0 times is supplied separately to the front roller, and the twist coefficient is 3.5 to 4 Elasticity with a blending ratio of polyolefin elastic fiber of 5 to 8.6%, characterized in that it is wound around a spinning cup above the draft tension of polyolefin elastic fiber while twisting at .5, and heat and heat set at 60 to 95 ° C. A method for producing a composite yarn. The polyolefin elastic fiber is supplied while drafting 2.5 to 5.0 times, and the non-elastic fiber is wound at 500 to 1200 T / m in the draft region and wound up without loosening. A method for producing an elastic composite yarn having a blending ratio of polyolefin elastic fibers of 5 to 8.6% , wherein the heat and humidity are set at a temperature of 0 ° C.