A kind of production method with high strength polyacrylonitrile fiber

Abstract

The invention relates to a method for producing a polyacrylonitrile fiber with high strength for reducing the internal stress of the polyacrylonitrile fiber. The method comprises the following steps: preparing spinning solution; performing wet spinning; performing multi-stage drafting; performing washing treatment; performing thermal shaping and the like. According to the method, the influence on a microscopic chain structure of the fiber due to over-large internal stress of the fiber caused by continuous, multi-stage and large-multiplying-power drafting can be effectively reduced; compared with the prior art, the method has the advantages that the strength of the polyacrylonitrile fiber is improved by 0.44 cN / dtex and is improved by 7.5 percent compared with the strength of the precursor fiber, the degree of orientation is improved by 3.86 percent, and the quality of the fiber is improved and is obviously improved.

Description

【Technical field】 [0001] The invention belongs to the technical field of polymer fiber processing. More specifically, the present invention relates to a method for reducing the internal stress of polyacrylonitrile fibers and producing polyacrylonitrile fibers with high strength. 【Background technique】 [0002] High-performance carbon fiber is a technology-intensive material. Carbon fiber not only has a series of excellent properties such as high specific strength and specific modulus, high electrical conductivity, low thermal expansion coefficient, high temperature resistance, corrosion resistance, creep resistance, and self-lubrication, but also has fiber Its flexibility and weaving properties are often used as reinforcements of advanced composite materials, and its application fields are widely used in various fields of military and civilian industries. Polyacrylonitrile fiber is the key to prepare high-performance carbon fiber, and its quality will directly affect the fi...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned patent application is to modify the existing equipment or add multi-stage constant pressure drafting equipment, which has high requirements for public works and layout, and the equipment processing is cumbersome. In addition, multi-stage high-magnification drafting tends to cause excessive internal stress of the fiber, which virtually increases the Difficulty in heat setting; spraying and washing stretching requires multi-stage water tanks and a large spraying space. In order to remove residual solvent as much as possible, a large amount of waste liquid will be generated, the drafting ratio is not high, and the effect is not obvious enough

[0005] At present, in the process of carbon fiber production, the draw ratio of the fiber is blindly increased to make the fiber finer, but it is often easy to ignore the influence of the internal stress of the fiber in the process of fiber formation, resulting in internal molecular chains in the fiber produced by high-strength drafting. Fracture occurs under the action of stress, so that the mechanical properties of the fiber do not increase but decrease, and cause "congenital" damage for the next high-temperature carbonization