A kind of preparation method of polyimide fiber filament

Abstract

The invention discloses a method for preparing polyimide fiber filament. The method comprises the following steps: (1) dry spinning: a polyamic acid solution prepared by a polymerization reaction is subjected to vacuum standing, defoaming and filtration, and then is extruded into a spinning tunnel through a spinning hole for dry spinning, in the spinning tunnel, a solvent is heated by high-temperature nitrogen and precipitated and taken out, then recovered after cooling, and a spinning solution is solidified into fiber; and (2) imidization: the fiber is simultaneously imidized and stretched bya GR1 to GR6 hot roller to obtain the finished polyimide fiber filament. The one-step method with imidization, spinning and stretching is beneficial to save space, reduce cost and improve productionefficiency; and the method also has high solvent recovery rate, is easy to operate, has low cost, and has certain environmental protection significance.

Description

technical field [0001] The invention relates to the technical field of polyimide fiber production, in particular to a method for preparing polyimide fiber filaments. Background technique [0002] Polyamideimide fiber has good high temperature resistance, acid corrosion resistance, antibacterial, insulation shielding, flame retardant, self-extinguishing, radiation protection and other functionalities. It belongs to high-performance fiber materials and is suitable for military industry, aerospace, etc., and Thermal insulation, light weight, and softness are also ideal materials for making military uniforms such as firefighting uniforms and navy uniforms. However, the strength of polyimide fibers is relatively low, which largely restricts the development of its applications, and is also an urgent need in the industry. The problem to be solved is that some manufacturers use the method of improving the polymerization formula to increase its strength, which not only increases the ...

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Problems solved by technology

[0002] Polyamideimide fiber has good high temperature resistance, acid corrosion resistance, antibacterial, insulation shielding, flame retardant, self-extinguishing, radiation protection and other functionalities. It belongs to high-performance fiber materials and is suitable for military industry, aerospace, etc., and Thermal insulation, light weight, and softness are also ideal materials for making military uniforms such as firefighting uniforms and navy uniforms. However, the strength of polyimide fibers is relatively low, which largely restricts the development of its applications, and is also an urgent need in the industry. The problem to be solved is that some manufacturers use the method of improving the polymerization formula to increase its strength, which not only increases the cost, but also reduces the performance of the polymer, and the overall effect is not good.

[0003] The existing production and preparation of polyamideimide is mostly solution wet spinning, and the spinning and subsequent imidization, stretching and other post-treatments need to be carried out step by step, and cannot be produced in one step.

The polyamic acid polymer is spun in the form of a solution. The solvent needs to be precipitated in the coagulation bath, and then the polyamic acid polymer macromolecules are solidified into fibers. This process is a low-temperature reaction, and the proportion of solvent precipitation is low. The solvent content is high, the filaments are easy to bond, unwinding is difficult, there are many broken ends, and the production efficiency is low. Moreover, post-processing such as spinning, imidization, and stretching is carried out step by step, which cannot be completed in one step, which affects the subsequent sub-processes. Amination and post-stretching properties, fiber product elongation at break and breaking strength fluctuate greatly, poor uniformity, poor mechanical and mechanical properties, and relatively low fiber strength, which affects its performance and application, and the cost of solvent recovery is high. Operation Inconvenient and polluting

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