High shrinkage side by side type composite filament and a method for manufactruing the same

Abstract

The present invention relates to a high shrinkage side-by-side type composite filament, wherein two kinds of thermoplastic polymers are arranged side by side type and a boiling water shrinkage (Sr2) measured by the method (initial load=notified denier×1 / 10 g, static load=notified denier×20 / 10 g) of clause 5.10 of JIS L 1090 is 20 to 75% of a boiling water shrinkage (Sr1) measured by the method (initial load=notified denier×1 / 30 g, static load=notified denier×40 / 30 g) of clause 7.15 of JIS L 1013. The side-by-side type composite filament is made of two kinds of thermoplastic polymers having a number average molecular weight difference (ïMn) of 5,000 to 15,000 upon spinning and the composite filament is drawn and heat-treated so as to satisfy the following physical properties: Temperature area exhibiting 95% of maximum thermal stress (Tmax, 95%): 120 to 230° C. Range of maximum thermal stress per denier: 0.1 to 0.4 g / denier

Description

TECHNICAL FIELD [0001] The present invention relates to a side-by-side type composite (conjugate) filament which has a high elastic property (shrinkage) even in a filament state, and to a method for manufacturing the same. [0002] More particularly, the present invention relates to a side-by-side type composite filament, which can omit a false-twisting process and can attain a fine denier filament since it has a superior crimp even in a filament state where no false-twisting treatment has been carried out, and to a method for manufacturing the same. BACKGROUND ART [0003] Synthetic fibers have reached the level not inferior to natural fibers in some properties owing to repeated technical development in spite of their short history. But, the crimp property is a property which is not easy for synthetic fibers to exhibit and is being considered as an intrinsic property of natural fibers such as wool. [0004] As prior art methods providing synthetic fibers with crimp properties are (i) a m...

AI Technical Summary

Benefits of technology

[0012] The present invention provides a side-by-side type composite filament which has a excellent shrinkage even in a filament state which is not passed false-twisting process. Additionally, the present invention provides a method for manufacturing a high elastic side-by-side type composite filament which has a simple process and can attain a fine denier filament since a false-twisting process can be omitted.

Problems solved by technology

But, the crimp property is a property which is not easy for synthetic fibers to exhibit and is being considered as an intrinsic property of natural fibers such as wool.

But, the above method was disadvantageous in that, since the appearance of crimps is uneven and the binding force of core yarns and effect yarns is relatively small because it is dependent upon air texturing and the like, one component yarn is released or removed by a physical force applied during a after-process or the crimping property is decreased.

In addition, the above method for manufacturing a different shrinkage composite false twisted yarn was problematic in that it is difficult to provide a fine fineness because two or more kinds of yarns have to be mixed, and the process becomes complicated and the manufacturing cost is increased because the two or more kinds of yarns pre-produced have to be rewound and combined again.

On the other hand, the method for mixing a polyurethane fiber and other synthetic fiber upon manufacturing woven or knitted fabrics was disadvantageous in that it is difficult to process because the synthetic fiber is different from the polyurethane fiber in physical and chemical properties.

Therefore, in a case that the polyester fiber and the polyurethane fiber are mixed upon manufacturing woven or knitted fabrics, there are many problems that, for example, it is necessary to use a chlorobenzene or methyl naphthalene carrier for dyeing, and the final product is weak to a chlorine bleaching agent and easily hydrolysable by NaOH.

Meanwhile, a synthetic fiber manufactured by a polybutylene terephthalate (PBT) resin has a problem that they have to undergo a false twisting process for improving elastic property because of their lack of shrinkage in a filament state.

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