Polytrimethylene terephtalate conjugate fiber and method of preparing the same

Abstract

Disclosed is a polytrimethylene terephtalate conjugate fiber having high self-crimpability, which is prepared by conjugate-spinning two types of polytrimethylene terephtalates having different intrinsic viscosities in which a difference between the intrinsic viscosities ranges from 0.05 to 0.15 into a side-by-side fiber. Also, the polytrimethylene terephtalate conjugate fiber prepared by the conjugate-spinning undergoes a false twisting process, leading to development of three-dimensional high self crimpability and sufficient bulky property in the resulting fiber.

Description

TECHNICAL FIELD [0001] The present invention, in general, relates to a polyester conjugate fibers and method of preparing such fibers. In detail, the present invention relates to a polyester conjugate fiber, and a method of preparing such a fiber, comprising conjugate-spinning two types of polyesters having different intrinsic viscosities to produce a fiber having a side-by-side cross-section, and subsequently performing a heat-treating and relaxation process to develop high self-crimpability and overall quality of the fiber. More particularly, the present invention relates to a method of preparing a polyester conjugate fiber, capable of developing crimpability and supplying good spinning operability even at a smaller difference between intrinsic viscosities of two polymers than a conventional intrinsic viscosity difference. BACKGROUND ART [0002] Several methods of preparing side-by-side conjugate fibers are conventionally known. As representative examples, one is to prepare such co...

AI Technical Summary

Benefits of technology

[0005] Leading to the present invention, the intensive and thorough research into a polyester conjugate fiber, conducted by the present inventors with an aim to achieve the above object, resulted in the finding that a conjugate fiber can be prepared by conjugate spinning two different types of trimethylene terephtalates having a difference of 0.05-0.15 in their intrinsic viscosities into a side-by-side fiber, with good spinning operabililty, and the resulting conjugate fiber exhibits high self-crimpability even in a flat yarn form, not in a false twist yarn form, in addition that, when a bicomponent conjugate fiber prepared by conjugate-spinning polymers having a small difference between their intrinsic viscosities is subjected to a false twisting treatment, difference in shrinkage of the polymers occurs owing to the difference in the intrinsic viscosities of the polymers, and latent torque is developed by false twisting at a heat treatment step, thereby giving a conjugate fiber with high crimpability as well as sufficient bulky property.

Problems solved by technology

However, such methods are disadvantageous in that copolymers typically have deteriorated physical properties and poor spinning operability, and resulting fibers have a limited crimping level.

However, additional fabric weave patterns should be designed to develop high elasticity, and it is especially hard to obtain satisfactory elasticity in fabric weaves having many cross-links of warp and weft.

Also, since crimp is not easily developed in a flat yarn form, the fiber in the flat yarn form must be processed into a false twisted yarn by a false twisting treatment to obtain desired crimpability.

Owing to such a difference in intrinsic viscosities, the fiber is severely curved at a lower part of a spinning nozzle, and spinning operability is very poor.

Especially, in the case that the difference in intrinsic viscosities of two components of a side-by-side fiber is small good spinning operability is obtainable, but it is hard to develop crimpability in a resulting fiber.

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