JPS6361423B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a knitted fabric having excellent flexibility. More specifically, after a fabric using splittable composite fibers is dyed and finished, it is passed between two compressed surfaces facing each other to improve the separability between the split fibers, thereby improving the cohesiveness of the filaments that make up the yarn. This is a method for producing a flexible fabric containing split fibers, which is characterized by disturbing the split fibers. In general, as a method for making woven or knitted fabrics soft, there has been a conventional method of crinkle finishing, such as so-called sanphorization, in which the woven or knitted fabric is pushed between a heating cylinder and an endless elastic band made of rubber or felt to create a rubbing effect. Are known. However, in such a method, it is not possible to improve the separation between the divided fibers, and undesirable effects on the quality such as slips in the fabric structure and increase in density occur. As a result of intensive studies regarding these problems, the present invention has been arrived at. That is, the present invention has the following configuration. A knitted fabric including a split composite fiber having a cross section consisting of a plurality of split polyamide polymers and a polyester polymer interposed between the polyamide polymers is treated with an alkali, and at least a portion of the polyester polymer is decomposed and removed. A method for producing a knitted fabric with excellent flexibility, characterized in that the polyamide split fibers obtained from the composite fiber are separated by compressing the knitted fabric between opposing roll surfaces. The present invention will be explained in detail below. The knitted fabric of the present invention contains at least a part of the split fibers obtained by splitting the splittable conjugate fibers, and preferably all of the split fibers. Here, the single yarn fineness after division of the knitted fabric is 1.2
Denier or less, preferably 1.0 denier or less is desirable. If the denier is 1.2 denier or more, a soft texture cannot be obtained from the fabric. When using fibers other than splittable composite fibers as part of the knitted fabric, it is preferable to use fibers with a single yarn denier of 1.2 denier or less, and fibers with a single yarn denier of 1.0 denier or less to obtain a fabric with a soft texture. It is more preferable to use Split fibers obtained by applying appropriate pretreatment such as scouring to a knitted fabric using splittable fibers of a combination of polyethylene terephthalate and nylon 6 or nylon 66, and then decomposing and removing the polyester polymer through alkaline bath treatment. make it easier for people to become separated from each other. Here, the polyester polymer may be any polymer that can be decomposed and eluted with an alkali, such as polyethylene terephthalate or polybutylene terephthalate, but particularly preferred is a polyamide polymer that can be easily decomposed and removed by an alkali and that can be used in the spinning process. It is a polyethylene terephthalate-based polymer copolymerized with 2 to 20 mol% of 5-sodium sulfoisophthalate, which does not easily peel off. However, in fiber splitting that does not involve the swelling process of the intervening component or any mechanical action, such as when a polyester polymer, which is an intervening component, is decomposed and eluted with an alkali, the split fiber group becomes the composite fiber before splitting. The arrangement is almost maintained, and some of the fiber characteristics before division tend to remain. This tendency is particularly remarkable when there are few intervening components, that is, when the opposing surfaces of the polyamide polymers facing each other via the intervening components are highly parallel and close to each other. Therefore, in order to sufficiently exhibit the softening effect of fine fiber formation, additional means are required to separate and disperse (rearrange) the split fibers (polyamide fibers). In other words, the knitted fabric from which intervening components have been decomposed and removed by alkali is subjected to dyeing, printing, etc. and finishing agent processing as necessary, and then inserted and transferred between two compressing roll surfaces facing each other. Ru. This allows the contact surface of the split fibers to move significantly, improving the separation between single fibers and providing a soft texture, which is an advantage of using ultrafine fibers. The compression roll used in the present invention has a smooth cylindrical surface, but may be heated by electric heat, steam heat, etc., if necessary.
The heating temperature needs to be changed depending on the desired texture and purpose, but it needs to be kept below a temperature that does not cause hardening of the knitted fabric, and a temperature of 80°C or lower increases the separation between the split fibers of the present invention and makes it flexible. Suitable for obtaining fabrics. It is desirable that the compressing roll surfaces face each other and can rotate in the direction of movement of the knitted fabric. Furthermore, the pressurization of the compressed surface can be arbitrarily changed depending on the desired texture and processing purpose as described above, and the transition speed can also be arbitrarily adjusted based on the same idea. As the pressurizing method, any other method such as a spring type, water pressure type, hydraulic type, etc. may be used. The material for the compression roll surface may be metal, ebonite, rubber, paper, etc., and any combination of these may be used. As described above, the present invention is similar to various conventionally well-known calender finishing processes in that the woven or knitted fabric to be treated is introduced and passed between the surfaces of two compression rolls facing each other. Most of them are used for surface treatment, and the contact surface of the calendar bowl, which rotates under strong pressure, is used to create smoothness, special luster, and polish, as well as to engrave a pattern on the metal bowl and transfer that pattern to the fabric surface. The purpose is to obtain special qualities such as embossing. However, in the present invention, it is not necessary to perform any special processing on these surfaces, and by transferring them through the roll surfaces that compress each other, it is possible to improve the separation between the split fibers, thereby achieving sufficient A major feature is that it provides flexibility. Furthermore, conventionally, calendering is sometimes performed as a treatment for softening the texture of general textiles. When this process is applied to a fabric made of ordinary yarn, and when this process is applied to a fabric made of split fibers as in the present invention, the softening effect is as shown in the Examples and Comparative Examples. is significantly different and much larger for split fiber fabrics. This processing separates the fibers that are continuously bonded in the longitudinal direction, so it can be said that the softening effect is large. Next, the present invention will be explained using examples. Example Nylon 6 with a sulfuric acid viscosity of 2.4 was used as the polyamide component, and ethylene 5-sodium sulfoisophthalate (5 mol%)/ethylene terephthalate (95 mol%) copolymer with an intrinsic viscosity of 0.53 in orthochlorophenol was used as the polyester component. Using normal composite spinning equipment, spinning temperature 263℃, spinning speed
A composite fiber in which the polyamide component was divided into three parts by the polyester component was obtained at 1200 m/min. The polyester component accounts for 15% by weight in this composite fiber. Continued stretching speed 400
Normal stretching was carried out at m/min with a hot pin at 100° C. and a stretching ratio of 3.4 times to obtain a drawn yarn of 83 denier and 24 filaments (70 denier and 72 filaments after splitting to remove the polyester component). This drawn yarn is used as warp yarn and weft yarn for plain fabric (warp yarn density 107 yarns/
2.54cm, weft yarn density 90/2.54cm).
This fabric is scoured in water at 98-100°C using Neugen and soda ash, and then placed in a hanging tank for 30 minutes.
After washing, dyeing was carried out in a NaOH aqueous solution at 100°C for 60 minutes, followed by dyeing with a Jitzger dyeing machine.
Finish setting was carried out in the usual manner. When the warp and weft yarns of the obtained taffeta were separated and observed under a microscope, it was found that although the polyester component was almost completely removed, each single yarn remained in the same alignment as before splitting and was in contact with each other. Ta. These finished fabrics were subjected to a pressing load of 2500Kg (62Kg/
cm ² ) between compressing roll surfaces facing each other. As a result of this processing, there was no tissue slip or change in density of the woven fabric, the separation between the split fibers was increased, the drapability was improved, and a woven fabric was obtained which had a desirable soft feel. In order to examine the texture of this fabric, the bending resistance of the fabric was measured using the cantilever method (JISL-1096A method). The results are shown in Table 1. As a comparative example, normal nylon thread length 70 denier,
A plain woven fabric (density 123 x 87/2.54 cm) using 12 filaments and 70 denier 24 filaments was processed using the same process as split fibers. The bending resistance results of the fabric are also shown.

[Table] As is clear from the results in Table 1, by carrying out this processing, the feel of the split fibers is much better than that of the normal yarn (comparative example), and this effect is recognized. Comparative Example A taffeta obtained by processing the same raw yarn as in the example under the same standards and conditions from weaving to dyeing to finishing set was pressed between an endless elastic band made of rubber and felt and a heating cylinder to create a kneading effect. I applied it. However, it was not possible to improve the desired separation between the split fibers, and the overall slippage occurred due to slippage, and as shown in Table 2 below, the density increased due to shrinkage, resulting in a fabric with a soft texture. I couldn't get it.

【table】

Claims (1)

[Claims] 1. A knitted fabric containing splittable composite fibers having a cross section consisting of a plurality of split polyamide-based polymers and a polyester-based polymer interposed between the polyamide-based polymers is treated with an alkali to decompose at least a portion of the polyester-based polymer. After removal, the polyamide split fibers obtained from the composite fibers are separated by compressing the knitted fabric between opposing roll surfaces, a method for producing a knitted fabric with excellent flexibility. .