Polyethylene solid wall pipe and its expansion forming device

Abstract

The invention discloses a polyethylene solid wall tube and an expansion forming device thereof, and relates to the field of forming equipment for plastic pipelines. According to the technical scheme,the expansion forming device comprises a machine base, wherein an annular far-infrared heating part which can sleeve the outer ring of the tube and is arranged at intervals with the tube; a port expansion mechanism embedded in the end part of the tube is further arranged on the machine base, the port expansion mechanism comprises a port expansion part, a guide mechanism and a driving device, wherein the port expansion part moves in the radial direction of the tube to expand a port of the tube, the guide mechanism is used for guiding and limiting the movement direction of the port expansion part, and the driving device drives the port expansion part to move. The device has the technical effects that 1, the annular far-infrared heating part is used for heating, heating equipment which uses glycerol as a heating medium is avoided, due to the fact the moisture is mixed inevitably in the glycerol, so that the decomposition temperature of the glycerol is reduced, a large amount of smog is generated, and the environment is polluted; and 2, the axial shrinkage rate of the tube is well controlled by changing heating modes and controlling the temperature difference, so that the use of the large-scale heating equipment is avoided, and the electricity consumption is saved by 50% compared with that of the large-scale heating equipment.

Description

technical field [0001] The invention relates to the field of molding equipment for plastic pipes, in particular to an expansion molding device for polyethylene solid-wall pipes. Background technique [0002] The tubing is easily uniaxially (ie, axially) stretched orientated during the forming process. This orientation can be achieved simply by increasing the speed ratio of pipe pulling and extrusion. However, this axial stretch orientation is meaningless to the performance of the pipe, because although it increases the strength of the pipe in the axial direction through stretch orientation, it reduces the radial, that is, the hoop strength of the pipe. [0003] This is very harmful to plastic pipes, especially water supply pipes. Because it will reduce the hydraulic burst strength of the pipe. This is also the reason why in the quality standard of the pipe, it is stipulated that the longitudinal retraction rate of the pipe must be less than or equal to 5%. Ideal stretch ...

AI Technical Summary

Problems solved by technology

[0005] To sum up, when the pipe is flaring, the radial direction of the pipe is increased, and the proportional flaring of the pipe becomes difficult. If the wall thickness of the pipe is reduced, the hoop strength at the pipe flaring will be reduced, which improves the The tightness of the interface, but the original hydraulic burst strength of the pipe cannot be maintained

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