Method and device for controlling multi-level coagulation bath concentration for spinning polyacrylonitrile protofilament

Abstract

The invention discloses a method and a device of multi-level coagulation bath concentration for spinning polyacrylonitrile protofilament. An automatic water-supplementing device is arranged in a coagulation bath at each level, and the concentration of each coagulation bath at each level is controlled by adjusting the water-supplementing speed of the automatic water-supplementing device. The water-supplementing speed is based on a the theory that the amount of supplemented water is equal to the sum of water which is purely brought by filaments out of the coagulation bath and water needed for diluting a good solvent released by the filaments from the coagulation bath to the concentration of the coagulation bath. Compared with the prior art, the invention has the advantages of convenient operation and simple equipment, overcomes operation errors brought by artificial intermittent water supplementation and can accurately control the coagulation bath concentration at each level so as to favorably produce stable high-performance polyacrylonitrile protofilament.

Description

technical field [0001] The invention relates to the technical field of spinning polyacrylonitrile precursors, in particular to a multistage coagulation bath concentration control method and device for spinning polyacrylonitrile precursors. Background technique [0002] Carbon fiber has many excellent properties such as low density, high specific strength, high specific modulus, high temperature resistance and corrosion resistance, and has been widely used in various fields of aerospace, national defense and civilian industries. According to the raw material route, carbon fiber can be divided into three types: polyacrylonitrile (PAN)-based, pitch-based and viscose-based. Among them, PAN-based carbon fiber has become a carbon fiber with the fastest development, the highest output, the most varieties and the widest application due to its simple production process, low production cost and excellent mechanical properties. [0003] It is well known that high-performance PAN precu...

AI Technical Summary

Problems solved by technology

However, at present, there are few reports on the control method of the concentration of the PAN precursor spinning coagulation bath

If the method of manually adding water to the coagulation tank is used to control the concentration of coagulation baths at all levels, it is difficult to achieve precise control of the concentration of coagulation baths due to human error, which is not conducive to the production of stable high-performance PAN precursors

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