A forming method of hdpe double-wall winding pipe

Abstract

The invention discloses a forming method for a high-density polyethylene (HDPE) double-deck twisted pipe. The forming method for the HDPE double-deck twisted pipe comprises the steps of material blending, plasticizing extruding, twisting, cooling, shaping and cutting, demolding and the like. The twisting process is improved, a cylindrical steel mold rotates and horizontally moves, the steel mold is continuously heated through flame, when the temperature reaches 125 DEG C-135 DEG C, a strip-shaped inner material begins to be twisted on the steel mold, the inner material presses 1 / 3-1 / 2 part ofa previous circle when rotating in each circle, then, a hollow cylindrical outer material is twisted on the inner material, the outer material presses the non-overlapped 2 / 3-1 / 2 part, the flame, the twisting pipe inner wall material and the outer wall material are kept unchangeable in position, and the rotating linear speed of the steel mold is larger than the extruding rate by about 1%-3%; and the performance of the materials is enhanced to a great extent, and the ring stiffness of the twisted pipe is improved. Through repeated practice, it proves that by means of the forming method, the ringstiffness of the HDPE double-deck twisted pipe can be improved by 15%-20%.

Description

technical field [0001] The invention relates to the technical field of winding pipes, in particular to a forming method of HDPE double-wall winding pipes. Background technique [0002] Buried drainage pipes are mainly used in large-scale sewage discharge, exhaust, ventilation of subways, tunnels, mines, etc., and low-pressure irrigation of farmland. Due to the low ring stiffness and poor external pressure resistance of plastic pipes, the pipe buckling deformation is often caused by excessive external pressure loads, which brings certain restrictions to the application of plastic underground drainage pipes in many large and medium-sized cities. Ring stiffness is a comprehensive parameter of the external pressure load resistance of plastic buried drainage pipes. At present, the numerical index of ring stiffness is widely used in the world to express the external pressure load resistance of plastic buried drainage pipes. If the ring stiffness of the pipe is too small, the pipe...

AI Technical Summary

Problems solved by technology

PE material has the advantages of good low-temperature impact resistance and high flexibility, but because the double-wall wound pipe has high requirements for the ring stiffness of the pipe, the shortcomings of PE material low modulus, insufficient strength and stiffness limit its use in double-wall wound pipes. Therefore, it is an urgent need to improve the rigidity of HDPE double-wall wound pipe under the existing conditions

[0004] And the forming method of current double-wall winding pipe is mainly to form naturally through the mould, as in Chinese patent CN106084449 A, the method of forming is, will be extruded by the inner and outer wall extruder of described double-wall winding pipe after plasticization. The fluid-like raw material is shaped by the double-wall winding pipe shaping mold, and after cooling, the HDPE double-wall winding pipe can be obtained. This method is simply to enter the mold after plasticizing the raw material for simple shaping; the forming method disclosed in Chinese patent CN 106009756 A It is: put the metal mesh cylinder in the mold cavity, pour the raw material melt into the mold cavity, and form a winding pipe after cooling; neither of these two winding pipe forming methods can optimize the performance of the existing material, so that when To improve the performance of the winding pipe can only be achieved by changing the material formula raw materials or increasing the use of materials, which increases the cost

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