Screw extrusion method for high polymer material pipe

Abstract

The invention relates to a screw extrusion method for a high polymer material pipe. The method comprises the following steps in sequence: driving a rotating screw to rotate through the rotation movement of a power gear and a driven gear, forwards conveying and gradually compacting a high polymer material; standing a sizing screw, and when the high polymer raw material reaches the sizing screw, filling the space formed by a machine tube and the sizing screw with the high polymer raw material to form a high polymer material pipe embryo; gradually plasticizing the obtained high polymer material pipe embryo under the joint action of friction heat, external heat of the machine tube and a heating screw to obtain the high polymer material pipe. According to the screw extrusion method the high polymer material pipe embryo does the absolute movement along with the direction of the screw, the quality of the high polymer material pipe embryo and the stability in the forming process can be improved, and the characteristic of plasticizing after forming is realized; and the high polymer material pipe formed can keep the physical property of raw materials.

Description

technical field [0001] The invention relates to a screw extruding method for polymer material pipes with poor melt fluidity or even no melt fluidity. Background technique [0002] At present, the commonly used molding methods for the molding of polymer material pipes with poor fluidity are: plunger extrusion molding; polymer materials are modified by flow process to increase their molding fluidity, and ordinary single-screw extrusion molding is adopted; Single-screw extrusion barrel molding method. [0003] Plunger extrusion molding can be regarded as continuous sintering molding. The molding process of this method is discontinuous, the plasticizing time is long, the production efficiency is low, and it is not suitable for molding large finished products, so it is limited in production and application. [0004] After modifying the flow process of polymer raw materials with poor fluidity, ordinary single-screw extrusion molding is used. Although it can be molded, the molding...

AI Technical Summary

Problems solved by technology

However, the movement form of the pipe parison formed by the patent ZL200710053227.2 technology is difficult to control. On the one hand, the pipe parison rotates with the screw, and on the other hand, it moves relatively linearly with the screw groove. The absolute movement of the pipe parison is a spiral motion.

During the forming process, with the reduction of the concentricity of the screw, the geometric dimension accuracy of the UHMWPE pipe parison formed by the space formed between the polished screw rod and the barrel is reduced, which affects the precise shaping of the UHMWPE pipe and the stability of the UHMWPE pipe forming.

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