An extrusion molding die for online biaxially oriented plastic large-diameter pipes

Abstract

The invention discloses an extrusion molding mould of an online biaxially oriented plastic large diameter pipe. The mould comprises a built-up hose forming zone, a heat preservation zone and a bidirectional expansion zone, wherein the built-up hose forming zone, the heat preservation zone and the bidirectional expansion zone are sequentially connected; the built-up hose forming zone comprises a mould body, a sprue spreader, a core mould bracket, a high temperature-resistant heat-insulating hose and connector, a machine head body, a bush die, a coaxial adjusting screw, a core rod, a heater, a thermocouple and a connecting screw; the high temperature-resistant heat-insulating hose and connector is arranged in the channel of the core rod and the core mould bracket. The extrusion molding mould has the following main innovative points: 1) a vacuum device and a channel which are mutually matched are arranged in a subsection of an expansion forming zone, so that height orientation of the pipe is guaranteed; 2) proper axial stretching ratio and radial stretching ratio are selected for the mould, so that the pipe with high-level orientation and a smooth and flat outer surface can be obtained; 3) the mould is simple and reasonable in structure, and the length of the core rod is shortened, so that coaxiality of the pipe and thickness uniformity of the pipe wall are improved.

Description

technical field [0001] The invention relates to an online biaxially oriented plastic extrusion molding die, in particular to an online biaxially oriented plastic large-diameter pipe extrusion molding die. Background technique [0002] When the thermoplastic pipe is extruded, the stretching in the axial and radial directions of the pipe is biaxial stretching. It has been proved by practice that the biaxially stretched pipe exhibits high physical and mechanical properties, greatly improves its strength and toughness, and greatly reduces the consumption of materials, so it has a wide range of applications. [0003] At present, most people use the online biaxial orientation extrusion molding die of the die drawing method. The die of this invention can produce pipes with relatively good strength and toughness, but the disadvantage of this invention is that: in the production of relatively large-scale pipes At the same time, due to the large diameter and long length of the mandre...

AI Technical Summary

Problems solved by technology

[0004] The invention provides an extrusion molding die for on-line biaxially oriented plastic large-diameter pipes, and provides a biaxially drawn pipe with high dimensional accuracy, easy control of the stretching process, and the ability to improve the size and surface quality of the stretched pipe. Extrusion molding dies and processes for extruding plastic pipes to solve the technical problems of poor coaxiality of pipes, serious unevenness of pipe wall thickness, complicated operation, large energy consumption, and high production costs in the prior art

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