Para-aramid fine denier fiber and preparation method thereof

Abstract

The invention relates to para-aramid fine denier fiber and a preparation method thereof. The method comprises the following steps: dissolving a para-aramid polymer in a strong acid, filtering twice, defoaming, performing tertiary filtration, spinning, stretching, cooling to solidify, rinsing, drying and rolling to finally prepare the finished fiber. In the preparation method, a high shear double screw extruder and a continuous film defoaming device are adopted, multiple filtering working procedures are adopted, the filtering precision characterized by the filtering plugging value Kw which is no more than 150, the defoaming purity, the spinning temperature, the stretching condition and the like are strictly controlled, the global optimization of process steps and process conditions is performed, the method is practical and is high in operability, and the para-aramid fine denier fiber with good physical properties can be prepared. The para-aramid fine denier fiber has the advantages of high strength and good quality, the fineness is 30-100D, the tensile strength is no less than 22CN / dtex, the elongation at break is no less than 2.5% and the initial modulus is no less than 550CN / dtex.

Description

technical field [0001] The invention belongs to the field of textiles, and in particular relates to a para-aramid fine-denier fiber and a preparation method thereof. Background technique [0002] Aramid fiber is a high-tech special fiber, which is widely used in high-strength tire and rubber industry, bulletproof materials and protective clothing, friction sealing insulation materials, aerospace structural parts, high-strength impact-resistant and wear-resistant composite materials, high-strength corrosion-resistant and Thermal cables and other fields have broad application prospects. With the advancement of aramid fiber preparation technology, the gradual expansion of production, and the good insulation and corrosion resistance of aramid fiber, its application in fiber-reinforced cables and communication electronic equipment has also expanded rapidly, especially in communication There is an increasing demand for aramid fine denier fibers in electronic devices. [0003] In...

AI Technical Summary

Problems solved by technology

This production method has the following disadvantages: 1) When the para-aramid polymer is dissolved in a strong acid system such as concentrated sulfuric acid, it will dissolve unevenly, and there will be gel particles, which will affect the spinning effect, and even make it impossible to spin. Normal spinning; 2) The degradation of aramid polymer in concentrated sulfuric acid increases with the increase of dissolution time and dissolution temperature, which easily affects the physical properties of the finished fiber; 3) Due to the high viscosity of the solution, it is difficult to defoam, and the residual bubbles will It will cause fuzz and broken ends, and even make it impossible to produce normally, which has a particularly obvious impact on fine denier fibers