Method and device for manufacturing plastic composite pipe with flexibly-knitted wire mesh skeleton

Abstract

The invention relates to a method and a device for manufacturing a plastic composite pipe with a flexibly-knitted wire mesh skeleton. A fixed mandrel is arranged in the center of a positioning disk of a steel wire knitting machine, and comprises a mandrel tail section, a mandrel middle section and a mandrel head section. Longitudinally-towed circumferential steel wire columns are arranged, spindles of linear steel wires are arranged about the fixed mandrel, and the linear steel wires run through a limiter one by one to be circumferentially uniformly arranged. The knitting machine longitudinally moves when crossing the mesh knitting steel wires outside the linear steel wires for cylindrical knitting. An extruder makes melted plastics pass through annular belts of hot runners of an injection node, so that the pressure of the plastics is uniformly distributed, and the plastics cover the wire mesh skeleton and are pushed forwards. Vacuum absorption shaping is performed on a formed pipeline rudiment by a shaping mould, thereby obtaining the plastic pipe with relatively smoother inner and outer walls. In the method and the device, the longitudinally-towed circumferential steel wire columns are adopted, so that diamond hole-shaped wire mesh skeleton knitting can be performed on the mesh knitting steel wires on the fixed mandrel with certain inclination and the circumferentially arranged linear steel wires thereof. The method and the device provided by the invention are simple, remarkably reduce the production cost and improve the production efficiency.

Description

technical field [0001] The invention relates to urban water supply and drainage pipes, in particular to a manufacturing method and device for a plastic composite pipe with a flexible braided wire mesh skeleton. Background technique [0002] In recent years, the municipal construction and renovation projects have developed greatly. For this reason, the construction department and the environmental protection department have put forward higher requirements for the pipes used in urban water supply and drainage. In the production of water supply pipes, a large number of polyethylene PE and HDPE materials are currently used. Compared with traditional steel pipes, ductile iron pipes, and cement pipes, polyethylene plastic pipes have a series of advantages such as safety and sanitation, stable and reliable pipe fittings, impact resistance, crack resistance, aging resistance, and corrosion resistance, especially the non-sticky inner wall material. The adhesion can avoid the formatio...

AI Technical Summary

Problems solved by technology

[0012] (1) The process is cumbersome, and the assembly line needs two extruders for inner and outer tubes, two hot-sol spraying machines and corresponding auxiliary devices

[0013] (2) Multi-layer structure, especially the hot melt in the middle layer is not the same material as the plastic in the inner and outer layers, and only depends on the transitional bonding of the inner and outer surfaces of the plastic pipe with hot melt adhesive, which affects the overall strength of the composite pipe

[0021] (1) The punching steel plate is limited by the process. Generally, the punching rate is about 20% to 30%. Therefore, the contact area of ​​the inner and outer plastics of the composite pipe is basically about 30%. Because the linear expansion coefficient of plastic and steel is almost the same An order of magnitude, so the internal stress shear force caused by temperature changes directly affects the quality of composite pipe products

[0022] (2) The skeleton adopts a series of processes such as punching and cutting, segmentation, reeling, and welding after precision cutting of steel plates, so the production process is cumbersome and the skeleton production cost is high

However, the axial steel bars are always in a strong tension state, and the axial steel bars will break, especially when thinner axial steel bars are used.

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