Preparation method of low-temperature dyeable composite elastic fiber

Abstract

The preparation method of the low-temperature dyeable composite elastic fiber comprises the following steps: preparing a PET (Polyethylene Terephthalate) slice and a PBT (Polybutylece Terephthalate) slice; respectively putting the slices into a parallel composite spinning device, respectively melting and flowing to a spinning mechanism; co-extruding from a spinneret orifice; the extruded mixed yarn is subjected to drafting, side blowing, heat setting and winding; when the PET slices are manufactured, a component C, namely meta-position aromatic dicarboxylic acid or esters thereof, is also added to increase the distance between PET macromolecules, and meanwhile, the PBT slices are formed by liquid phase tackifying in a polycondensation kettle in the polymerization process or solid phase tackifying after polymerization and have the viscosity of 0.9-1.25 dl / g; in the extrusion process, the PET is adhered to the PBT for co-extrusion. The method has the advantages that the composite elastic fiber produced by the method has the characteristics of dyeability at low temperature and normal pressure, uniform coloring and high curling elasticity, and the prepared elastic fabric has the characteristics of uniform color and good elasticity retentivity.

Description

technical field [0001] The invention relates to the technical field of making elastic fibers, in particular to a method for preparing low-temperature dyeable composite elastic fibers. Background technique [0002] Polybutylene terephthalate (PBT), compared with its homologues polyethylene terephthalate (PET) and trimethylene terephthalate (PTT), has a softer molecular chain, And it has the elasticity similar to PTT, the glass transition temperature is 40-50°C, the melting point is 225-235°C, and can be dyed at low temperature and normal pressure, while the glass transition temperature of conventional PET is 67-81°C, the melting point is 250-260°C, and the macromolecular structure is tight , there is a lack of groups that adsorb ionic dyes in the molecule, so it is difficult to dye, and disperse dyeing requires high temperature or the addition of a carrier. Due to the different heat resistance properties of PET and PBT, when they encounter high temperature, the heat shrinkag...

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Problems solved by technology

The dyeing temperature difference between the two is nearly 40°C, which leads to the PBT / PET side-by-side self-crimping composite fibers prepared by this method, and the dyeing often has different colors and uneven coloring, that is, under the same dyeing conditions, the PBT component The deep color and the light color of the PET component cause color difference between the two sides of the same thread; after weaving the fabric surface, there will be uneven phenomena such as stripes and patterns, resulting in defective products; on the other hand, although high temperature dyeing at 130°C can Level the color difference between the two components, but such a high dyeing temperature will limit the application of this filament in low-temperature dyed varieties, such as wool, cotton fabrics, etc.

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