Preparation method of high concentration ultrahigh molecular weight polyethylene fiber spinning solution

Abstract

The invention relates to a preparation method of a high concentration ultrahigh molecular weight polyethylene fiber spinning solution. The preparation method comprises the following steps: step one, subjecting polyethylene powder, a mixed solvent, and an antioxidant to pressurization, heating, stirring, and swelling to obtain suspension of swelled body; step two, subjecting the suspension obtained in the step one to reduced pressure flash evaporation, separating and storing a solvent A with a low boiling point in a buffer tank, and discharging the suspension after flash evaporation; and step three, feeding the suspension obtained in the step two into a double screw extruder to carry out high temperature dissolution to radically unwind molecular chains through mixing by double screws so as to obtain the high concentration polyethylene fiber spinning solution. Compared with the prior art, after the swelling process, the swelled suspension is rapidly cooled through flash evaporation so as to prevent excess swelling. The preparation method can prepare a uniform polyethylene spinning solution with a polyethylene mass percentage of 15 to 50%. The solvent extraction step is not needed, the production efficiency is largely improved, at the same time, the low boiling point solvent generated in flash evaporation can be condensed, recovered and reused, and the production cost is reduced greatly.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and relates to a preparation method of a high-concentration ultra-high molecular weight polyethylene fiber spinning solution. Background technique [0002] With the rapid development of science and technology, the demand for special fibers in the engineering and technical circles is increasing. UHMWPE fiber is another high-performance fiber that appears after carbon fiber and aramid fiber under this trend. Ultra-high molecular weight polyethylene fiber has excellent performance and wide application, its raw materials are easy to get, and its preparation process is relatively simple. [0003] Ultra-high molecular weight polyethylene fiber has the characteristics of light weight, high strength, long service life, wear resistance, high strength, moisture resistance, and corrosion resistance, and is widely used in towing ropes, negative force ropes, rescue ropes, and cut-resistant gloves. ...

AI Technical Summary

Problems solved by technology

The use of high-boiling-point solvents requires additional solvent extraction steps during desolventization, which increases the complexity of the process, but the cost of the solvent used is lower; the use of low-boiling point solvents requires higher solvent costs and requires more precise control of the process flow , but the steps are simplified and the yield is higher

The current technology is difficult to recycle the separated solvent, even if it is recycled, the cost is high, so the use of solvent has become the main cost consumption of jelly spinning

[0006] The higher the concentration of the spinning solution, the higher the yield, the less the amount of solvent used, and the lower the cost. However, in the traditional gel spinning method, the solution concentration is too high, which will lead to uneven dissolution of raw materials and incomplete unwinding , and then at the exit of the twin-screw die, the phenomenon of broken wire or die plugging will seriously affect the production process, and the finished wire is prone to defects, resulting in a decrease in mechanical properties. This is also the main contradiction that currently limits the increase in the concentration of spinning solution

[0007] In order to further increase the concentration of the spinning solution and avoid broken filaments and decrease in mechanical properties, CN101956238B mixes the ultra-high molecular weight polyethylene solution and the ultra-high molecular weight polyethylene swelling solution in a weight ratio of 0.42-2.85 to obtain an ultra-high molecular weight The spinning dope with a polyethylene weight content of 10%-15%, CN101575743B cools the swelling suspension through a storage bin to obtain a spinning dope with a mass ratio of 4%-25%, although the two can slightly improve the spinning The concentration of the solution, but the operation is complicated and the efficiency is low, and the cost reduction is not obvious when the cost is reduced by increasing the concentration of the solution.

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