Pre-oxidized fiber and preparation method thereof

Abstract

The invention belongs to the technical field of preparation of fiber material preparation, and particularly relates to a pre-oxidized fiber and a preparation method thereof. The pre-oxidized fiber hasan obvious skin-core structure and comprises a skin layer and a core layer, wherein the density of the skin layer is 1.38-1.41 g / cm<3>, and the density of the core layer is 1.34-1.38 g / cm<3>. The preparation method of the pre-oxidized fiber comprises the steps that a polyacrylonitrile precursor as a raw material is subjected to fiber feeding, primary pre-oxidation, secondary pre-oxidation, traction, crimping, drying for setting and collection, wherein the temperature of the primary pre-oxidation is 80-160 DEG C lower than the temperature of the secondary pre-oxidation. Through research, the technical staff find that the skin-core structure is beneficial, on the one hand, the density of the outer skin layer is high so that it can be ensured that the pre-oxidized fiber is high in flame resistance; on the other hand, the density of the inner core layer is low, so that there are fewer fiber hole defects, the strength retention is high, and the processibility of the pre-oxidized fiber is easily improved.

Description

technical field [0001] The invention belongs to the technical field of fiber material preparation, and in particular relates to a pre-oxidized fiber and a preparation method thereof. Background technique [0002] Pre-oxygenated fiber has good flame retardant performance, high oxygen limiting index, non-combustibility under open flame, no melting drop, good thermal insulation performance, excellent sound absorption effect, and has obvious advantages compared with intrinsic flame retardant fibers such as aramid fiber and polyimide fiber. It can be made into yarn, felt, cloth and other product forms alone or blended with other fibers, and can be widely used in fireproof blankets, fireproof felts, flame-retardant underwear, protective clothing, sound-absorbing barriers and other product fields. [0003] At present, pre-oxidized fibers are mostly intermediate products for the production of carbon fibers, and polyacrylonitrile precursors for carbon fibers are used as raw materials...

AI Technical Summary

Problems solved by technology

However, this pre-oxygenated fiber production process is based on the ultimate goal of producing high-performance carbon fibers, while ignoring the performance of the pre-oxygenated fiber itself, resulting in low strength of the pre-oxygenated fiber, and the single-filament strength is below 300MPa. Processability and poor tear resistance and wear resistance of downstream products have a great negative impact

At the same time, since the oils of polyacrylonitrile precursors for carbon fibers are mostly high-temperature-resistant silicon-containing oils, they cannot be decomposed and removed only by pre-oxidation temperature, and black smoke will be generated when encountering an open flame, which will affect product performance.

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