A vacuum imidization furnace and an imidization method for polyamic acid fibers

Abstract

The invention provides a vacuum imidizing furnace comprising a hearth, an external heat insulating layer, a vacuumizing tube, a sealing device, 5-9 heating devices, a heating protective device, a net frame and an openable end enclosure, wherein the external heat insulating layer is arranged outside the hearth, the vacuumizing tube and the openable end enclosure are respectively arranged at the two ends of the hearth, the openable end enclosure is arranged at the open end of the hearth and is used for opening and closing the hearth, the heating devices are arranged in the hearth, the heating protective device is arranged outside the heating devices, the net frame is arranged outside the heating protective device, a fiber to be treated is sleeved outside the net frame, and the sealing device is arranged between the net frame and the hearth. By utilizing the vacuum imidizing furnace, the fiber can be thermally cyclized but cannot be oxidized, decomposed or carbonized at a high temperature, so that the mechanical performances of the prepared polyamide acid fiber can be improved.

Description

technical field [0001] The invention relates to the technical field of polymers, in particular to a vacuum imidization furnace and an imidization method of polyamic acid fibers. Background technique [0002] At present, with the development of science and technology, various high-tech fibers are playing an increasingly important role in national economic and social development. Polyimide fiber has become one of the important varieties of high-tech fibers due to its excellent properties such as radiation resistance, high temperature resistance, high strength and high modulus. [0003] The polyimide fiber is prepared by a two-step method. First, the polyamic acid fiber is obtained by spinning polyamic acid as a raw material, and then the polyimide fiber is obtained through imidization. Among them, polyamic acid fibrils need to be imidized by heating equipment before they can be transformed into polyimide fibers. Ordinary heating furnaces cannot meet the imidization condition...

AI Technical Summary

Problems solved by technology

Ordinary heating furnaces cannot meet the imidization conditions, which will cause incomplete imidization of fibers, or high-temperature carbonization, or serious parallel filaments, etc.

Chinese patents CN101986077B and CN201962442U disclose this kind of equipment, but the disadvantages are that the prepared fibers have low performance, poor strength, and many hairs.

Although the use of a vacuum oven can improve the disadvantages of ordinary furnaces, due to the discrepancy between the control temperature and the actual temperature in the vacuum oven, the serious hysteresis of the temperature, the uneven temperature caused by heat radiation, and the severely limited amount of processed fibers, etc., therefore, Ordinary heating furnaces and vacuum ovens cannot meet the requirements of imidization of polyamic acid fibers. In order to prepare high-performance polyimide fibers, special imidization equipment is necessary. The vacuum imidization equipment provided by the present invention The imidization furnace caters to the demand for special equipment for the development of polyimide fibers, and can be mass-produced to facilitate industrialization

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