JPH07278982A - Combined spun yarn - Google Patents

Abstract

PURPOSE:To obtain lightweight combined spun yarn rich in bulkiness, excellent in thermal insulation, and hard to develop whitish spoilage even under friction in a flat or flexed state. CONSTITUTION:This combined spun yarn with sheath-core structure is obtained by mutually superposing hollow filament yarns 10-40% in hollow rate and >=8% in boiling water shrinkage rate and staple fiber bundles followed by twisting and then treatment with boiling water. The weight ratio of the hollow filament yarns as the core to the staple fiber bundles as the sheath stands at <=1.5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite spun yarn which is lightweight and has excellent bulkiness and heat retention.

[0002]

2. Description of the Related Art Conventionally, as a means for reducing the weight, improving the bulkiness and improving the heat retaining property, hollow filament yarns or staple fibers having a hollow central portion of the fiber cross section have been used for clothing applications. Is well known. This is because these hollow filament yarns and staple fibers have a higher specific volume and an increased air content as compared with ordinary fibers. However, hollow filament yarns and staple fibers generally tend to be deformed by external pressure due to their shape, so that cracks or cracks are likely to occur on the fiber side surface, and the surface is likely to be subjected to repeated friction. There is a drawback that fibrillation causes whitening and drastically reduces the commercial value. Therefore, in practical use, consideration has been given to prevent the above problems from occurring as much as possible by methods such as blending with normal fibers, interlacing or interweaving, but this is sufficient because the hollow fibers exposed from the yarn or fabric are disturbed. At present, there is no choice but to place restrictions on usage such as back usage and partial usage. In addition, although attempts have been made to control the fibrillation by setting the fiber hollow ratio to a low level, weight reduction, bulkiness, and heat retention are sacrificed as the specific volume decreases, and the significant difference from ordinary fibers becomes poor. There was a problem that it could not fully exhibit its features because it was hollow.

[0003]

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem and is lightweight, rich in bulkiness, excellent in heat retention, and less likely to cause a whitening phenomenon even when it is rubbed against a flat surface or bent. An object of the present invention is to provide a composite spun yarn.

[0004]

In order to solve this problem, the present invention is designed such that a hollow filament yarn having a hollow ratio of 10 to 40% and a boiling water shrinkage ratio of 8% or more and a short fiber bundle are superposed and twisted. Which is a composite spun yarn having a core-sheath structure, wherein the mixing weight ratio of the hollow filament yarn of the core part and the short fiber bundle of the sheath part is core /
The gist is a composite spun yarn characterized in that the sheath is ≤1.5, and the yarn is formed and then treated with boiling water.

The present invention will be described in detail below. The hollow filament yarn referred to in the present invention is one in which one or more hollow portions are present in the fiber cross section, and cavities are continuously formed along the fiber axis. Composed of a plastic polymer. As the thermoplastic polymer forming the filament yarn, for example, a polyester-based polymer such as polyethylene terephthalate or copolyester, or a thermoplastic polymer such as polyacrylonitrile polymer can be adopted. It may be any of yarn, monofilament yarn, processed yarn, and the like. Furthermore, when the filament yarn is a multifilament yarn, it may be twisted or untwisted. The hollow ratio of the hollow filament yarn referred to in the present invention is 10 to 40%. The term "hollowness" as used herein means the volume (V ₁ ) of the fiber per unit length and the volume (V ₂ ) of the hollow portion of the fiber per unit length, and is represented by the following formula (1). It is a thing.

Hollow ratio (%) = (V ₂ / V ₁ + V ₂ ) × 100 (1) When the hollow ratio of the filament yarn in the composite spun yarn of the present invention is less than 10%, mixing with short fiber bundles occurs. Since the hollow ratio of the composite yarn is reduced by the weight ratio, practically,
It is difficult to make a significant difference in weight reduction and heat retention.

On the other hand, when the hollow ratio of the filament yarn exceeds 40%, the hollow filament yarn is easily deformed by external pressure, and in an extreme case, it becomes difficult to maintain the hollow shape because the fiber cross section becomes flat. And easily fibrillate. Therefore, the hollow ratio of the hollow filament yarn in the present invention is 10 to 40%, preferably 15% to 3
5%. The boiling water shrinkage of the hollow filament yarn referred to in the present invention is 8% or more. The term "boiling water shrinkage rate" as used herein means the following in accordance with JIS L-1013-7.15B method: the yarn length (L ') after treatment with boiling water and air drying and the yarn length (L) before treatment are measured. It is calculated by the equation (2).

Boiling water shrinkage (%) = [(LL ′) / L] × 100 (2) In the composite spun yarn of the present invention, the hollow filament yarn of the core has a boiling water shrinkage of less than 8%. This is because the variation in coating of the short fiber bundles in the sheath portion during the composite spinning cannot be improved to a good coating state due to the shrinking action. On the other hand, when the boiling water shrinkage rate becomes extremely large, the density of the woven or knitted product obtained when a woven or knitted product is made using this composite spun yarn becomes too large, deforms the hollow shape, and deteriorates the feel, This is not preferable because it makes it difficult to control the processing process. Therefore, in the present invention, the boiling water shrinkage of the hollow filament yarn is 8% or more, preferably 10 to 1
5%.

The short fiber bundle referred to in the present invention is composed of ordinary spinnable short fibers, for example, viscose rayon fibers and polynosic fibers produced from ordinary raw materials such as cotton, hemp and pulp. Alternatively, various short fibers such as polyester, acrylic and nylon, which are spun into an appropriate thickness necessary for spinning and cut into an appropriate length, can be adopted.

In the composite spun yarn of the present invention, the mixing weight ratio of the hollow filament yarn forming the core portion and the short fiber bundle of the sheath portion must be core / sheath ≦ 1.5. When the core / sheath ratio exceeds 1.5, the coverage of the short fiber bundle on the hollow filament yarn is extremely deteriorated, and the exposed portion of the hollow filament yarn in the core portion increases from the yarn side surface of the composite spun yarn. This is because, when it is repeatedly rubbed, it causes fibrillation as described in the above-mentioned conventional example and whitens.

The composite spun yarn in the present invention must be treated with boiling water after the yarn is formed. This is because the coating variation of the short fiber bundle of the sheath portion that occurs during the composite spinning is treated with boiling water, and the filament yarn of the core portion is contracted in the yarn axis direction, so that uniform and good coatability can be obtained. The boiling water treatment may be carried out in the state of the yarn or after making it into a woven or knitted material, and the boiling water treatment may be carried out alone or in combination with dyeing.

The boiling water treatment may be carried out at normal pressure or at high pressure, but it is desirable to carry out the treatment in an appropriate loosened state so that the yarn or the woven or knitted fabric can shrink smoothly. The composite spun yarn of the present invention is a hollow fiber prepared for the core part by supplying the short fiber roving yarn prepared for the sheath part to the draft part of the spinning machine and on the nip point of the front roller immediately before the completion of the draft. It is obtained by arranging and supplying filament yarns so as to overlap each other and twisting them. The twisting mechanism in the spinning machine may be a system using a ring and a traveler, or a bundling system in which high-pressure air is jetted to perform false twisting and twisting.

With the above-described structure, the present invention solves the problems of the conventional hollow filament yarn, staple fiber, and woven / knitted fabric made thereof, and is lightweight, rich in bulkiness, excellent in heat retention and friction. This makes it possible to obtain a composite spun yarn in which the whitening phenomenon hardly occurs.

[0014]

The present invention has a core-sheath structure in which hollow filament yarns are arranged in the core portion and short fiber bundles are arranged in the sheath portion in order to prevent cracks, cracks due to deformation peculiar to the hollow filament fibers and whitening phenomenon due to frictional abrasion. After the composite spun yarn is treated with boiling water, the shrinking action of the hollow filament yarn of the core part uniformly improves the covering property of the short fiber bundle of the sheath part. It is possible to obtain a state in which the resin is almost completely covered in appearance. Therefore, even if disturbances such as external pressure and frictional friction act on the composite spun yarn and the woven or knitted fabric made by it, the whitening phenomenon can be avoided, and the composite spun yarn that is lightweight and rich in bulkiness and excellent in heat retention can be obtained. Obtainable.

[0015]

EXAMPLES Next, the present invention will be specifically described with reference to examples. The polyester multifilament yarns A, B, C, D and E having the hollow ratio and the boiling water shrinkage ratio shown in Table 1 and the polyester multifilament yarn F normally spun as a comparative example were obtained.

[0016]

[Table 1]

Next, the combed cotton roving (a) prepared in the usual process and the above-mentioned 6 kinds of polyester multifilament yarns are set and arranged in a spinning process in ring spinning so that the yarn structure becomes a core-sheath. , 6 types of composite spun yarns 36 ^S (cotton count) of a, b, h, d, h, and f shown in Table 2 were obtained.

[0018]

[Table 2]

The 6 types of composite spun yarns obtained were used for warp and weft, respectively, to weave a plain woven fabric having a warp density of 80 yarns / inch and a weft density of 70 yarns / inch, and then 100 with a jet dyeing machine.
Heat and stir shrink treatment with boiling water at 30 ° C for 30 minutes, then dye the polyester side with a disperse dye and the cotton side with a reactive paint in dark blue, and pressurize with a cylinder drier. After drying, six types of processed woven fabrics corresponding to the composite spun yarn samples A to F were obtained.

Table 3 shows the results of comparative evaluation of the specific fabric volume, heat retention and abrasion whitening of the six types of processed woven fabrics of Samples A to F thus obtained. The measuring method is as follows.・ Dough specific volume (cc) = Dough thickness (cm) x 1 / Basis weight (g / cm
Calculated in ² ).・ Heat retention (clo) = Thermo Lab II manufactured by Kato Tech Co., Ltd.
Measures heat retention with a die tester. -Abrasion whitening = Observing changes in appearance after 40 minutes of abrasion at a rate of 30 times / minute using a Gakushin-type abrasion tester in accordance with JIS L-1084 A-1 method.

[0021]

[Table 3]

The evaluation of abrasion whitening in Table 3 was conducted by rubbing for 40 minutes with a Gakushin-type abrasion tester, and after marking the sample of Comparative Example as a reference, the appearance of whitening change was the same or hardly changed. Was evaluated by visually observing an X mark for those that changed to such a degree that they pose a problem in practical use. As is clear from Table 3, the woven fabric a of the composite spun yarn according to the present invention has a specific volume of 30% or more, that is, it is light and rich in bulkiness, and the heat retention is improved by 30 to 40%. It was an excellent product that was no different from conventional products.

On the other hand, in the sample B having a high hollow polyester mixture ratio, abrasion whitening is exhibited, and in the sample C having a low boiling water shrinkage ratio, the bulkiness and wear whitening are inferior. On the other hand, in the case of E having an excessively high hollow ratio, the hollow shape was deformed by the pressure applied during the processing step, and as a result, it was inferior in lightness and bulkiness and abrasion whitening.

[0024]

As described above, according to the present invention, it is possible to obtain a composite spun yarn which is light in weight, rich in bulkiness, excellent in heat retention and hard to cause the phenomenon of whitening even when it is rubbed on a flat surface or bent. .

Claims (1)

[Claims] 1. A composite spun yarn having a core-sheath structure in which hollow filament yarns having a hollow ratio of 10 to 40% and a boiling water shrinkage ratio of 8% or more and short fiber bundles are superposed and twisted, A composite spun yarn characterized in that the mixing weight ratio of the hollow filament yarn and the short fiber bundle of the sheath portion is core / sheath ≦ 1.5, and is made by boiling water treatment after the yarn formation.