Off-line steam drawing process method of polyacrylonitrile-based protofilament

Abstract

The invention discloses an off-line steam drawing process method of a polyacrylonitrile-based protofilament, and is a modified technology. The method aims at vices in the conventional on-line steam drawing production. An off-line steam drawing process flow comprises a front production line and a back production line, which are separated, wherein the front production line comprises: metering stock solution, spraying threads, cooling with a coagulating bath, washing and drawing, oiling, drying, doffing or coiling, and taping-out a protofilament drum or filament coil to be drew; the back production line comprises: conveying the protofilament drum or filament coil to be drew in batches to a pinch roller, a multi-roll draw machine and a steam draw machine, drying or thermally sizing, and doffing or coiling to obtain finished protofilament after steam drawing of the polyacrylonitrile-based protofilament. According to the invention, the production efficiency of the polyacrylonitrile-based protofilament can be improved, the steam energy consumption is reduced, the product quality is ensured, and the production cost is greatly reduced.

Description

technical field [0001] The invention relates to an off-line steam drafting process for polyacrylonitrile-based raw silk, and belongs to the technical field of polyacrylonitrile-based carbon fiber raw silk preparation. 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 aerospace, military, civil and other fields. According to the raw material route, carbon fiber can be divided into three types: polyacrylonitrile-based, pitch-based, and viscose-based. in, get together Due to its simple production process, low production cost and excellent performance, acrylonitrile-based carbon fiber has become a carbon fiber with the fastest development, the highest output, the most varieties and the most widely used. [0003] As we all know, high-performance polyacrylonitrile-based precursors are the prerequisite for pr...

AI Technical Summary

Problems solved by technology

The existing process of steam drafting is online drafting, that is, continuous drafting on the production line. This method has the following disadvantages: (1) Before the online raw silk enters the steam drafting, the tow has a speed of 20-100 m / min , so that the steam drafting can be completed at a higher speed. In order to ensure sufficient drafting temperature and drawing time, the steam drafting box needs to be longer; (3) Due to the shortcomings of (1) and (2), the spinning speed of the raw yarn cannot be greatly increased; (4) Due to the steam drafting line, the drafted yarn in the steam drafting box The number of bundles must be in one-to-one correspondence with the number of spinning spindles, which limits the output and wastes more steam

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