Preparing method of PET/PTT parallel complex filament with high self-crimpiness

Abstract

The invention discloses a preparing method of a PET / PTT parallel complex filament with high self-crimpiness. PET and PTT are sliced, dried and crystallized, afterwards, the PET and PTT are fused separately and subjected to extrusion molding through a parallel-type spinneret plate, oil is applied after cooling, then level 1-3 drafting and heat setting treatment are adopted, during drafting, the total drafting rate is controlled to be 3-3.5, the level-1 drafting rate is 2.8-3.0, and the temperature is controlled to be 75-80 DEG C. According to the preparing method of the PET / PTT parallel complexfilament with high self-crimpiness, methods like multi-level drafting for increasing the drafting rate are adopted, and the effects of improving the fiber strength, moderately lowering the elongationat break, and greatly improving the self-crimpiness are achieved.

Description

Technical field: [0001] The invention relates to the field of chemical fibers, in particular to a preparation method of high self-crimping PET / PTT side-by-side composite filaments. Background technique: [0002] At present, my country's chemical fiber output is huge, but the phenomenon of homogeneity and isomorphism is serious. Composite fiber is an important category of differentiated fibers at present. It is a new type of chemical fiber developed in the 1960s. The side-by-side composite fiber is a composite type in which two components exist side by side and only partially adhered. It is based on the internal crimp mechanism of wool. , a new variety developed using the principles of bionics. The PET / PTT side-by-side composite fiber is a composite fiber with spontaneous crimp obtained through melt composite spinning by utilizing the shrinkage difference between PTT and PET. Due to its relatively low cost, it has gradually realized commercial application. [0003] At prese...

AI Technical Summary

Problems solved by technology

[0003] At present, the industrial production of PET / PTT side-by-side composite fibers in my country is still in its infancy. Many domestic manufacturers have problems such as blind obedience and unclear fiber properties. PET / PTT side-by-side composite fiber products generally have poor comprehensive performance and poor quality. A series of problems such as unevenness and confusion of standard requirements

For example: Although many documents and patents mention that the crimp shrinkage rate is over 80%, it is difficult to measure this index uniformly due to the non-uniform test standards

According to the industrial testing method of PTT / PET self-crimping yarn elasticity proposed by patent ZL201510570077.7, the crimp recovery rate of PET / PTT side-by-side composite fibers at home and abroad is only lower than 40%, and the crimp rate is difficult to reach 45%, and the self-crimping ability is limited , it is difficult to meet the fabric demand of the back road

The fundamental reason is that the melting points and melt viscosities of PET and PTT two-component raw materials differ greatly (PET melting point is 260°C, melt viscosity is low, while PTT melting point is 225°C, melt viscosity is high and high temperature is easy to degrade), and the draft ratio is difficult to increase ( Generally, it is 1 to 2.5 times, too high a draft ratio is poor in stability), the winding speed is low (less than 3500m / min), the linear density is too large (the linear density is generally 4 to 5dtex) and many other factors exist