Hot air drying method of PVA fibers and drying ovens

Abstract

The invention discloses a hot air drying method of PVA fibers and drying ovens. The method is characterized in that the neutral washed tows from the previous procedure are subjected to liquid squeezing by liquid squeezing rollers to form the liquid squeezing tows, the liquid squeezing tows are led into hot air ovens connected in series in sequence by tow leading strips, the hot air ovens include multi-stage drying ovens, a preheating oven, an extending oven and a shrinking oven which are connected in series in sequence, in each hot air oven, the tows are supported on the rollers in the shape like a Chinese character zhi and each hot air oven carries out heating by way of circulating hot air; and the tows at the outlet of the shrinking oven can be cut or wound after being cooled by a cooling roller. The method can reduce the surface temperature difference of the tows, avoid fiber adhesion and improve the quality of the PVA fibers.

Description

Technical field [0001] The invention relates to a method for preparing PVA fibers, more specifically a hot air drying method for PVA fibers. Background technique [0002] In the manufacturing process of polyvinyl alcohol fiber, the heat treatment process is responsible for the continuous drying and dry heat stretching of the wet PVA fiber. In the heat treatment process, the heat treatment conditions determine the intrinsic quality of the PVA fiber, the color of the fiber, the degree of adhesion of the fiber, etc., and the adhesion of the fiber will directly affect its application. [0003] In the existing heat treatment process, the tow to be processed is heated by electric heating, the tow runs between the rollers, and the resistance wire or quartz tube is used as the heat source. By controlling a certain speed ratio of the front and rear rollers, the tow is in the rollers. High-strength and high-modulus PVA fiber with average strength ≥11.5CN / dtex and modulus 280CN / dtex is obtai...

AI Technical Summary

Problems solved by technology

[0003] In the existing heat treatment process, the tow to be treated is heated by electric heating, the tow runs between the rollers, and the resistance wire or quartz tube is used as the heat source. The number of turns in the middle, the temperature and temperature distribution of each oven can obtain high-strength and high-modulus PVA fibers with an average strength of ≥11.5CN / dtex and a modulus of 280CN / dtex, but it is difficult to stably obtain an average strength of ≥13CN / dtex and a modulus of 320CN / dtex high-strength and high-modulus PVA fiber, and the appearance of the obtained fiber product is slightly yellow, the dispersibility is not high, and the dispersibility fluctuates greatly during the production process

Due to dispersion reasons, the expansion of the fiber application field is restricted

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