Large-diameter PE straight-wall pipe startup molding and towing device and startup method thereof

Abstract

The invention discloses a large-diameter polyethylene (PE) straight-wall pipe startup molding and towing device and a startup method thereof. The device comprises a dragger, a cooling sizing water tank, a sizing sleeve and an extrusion die and also comprises a steel rope coiling device, wherein the steel rope coiling device is arranged opposite to the outlet of the dragger; and the extrusion die is provided with an air inlet pipeline. The startup method comprises the following steps of: (1) extruding a pipe blank, gluing and sealing the pipe blank, and fixedly connecting a steel rope; (2) dragging the pipe blank; (3) performing internal pressure sizing; (4) performing negative pressure molding; and (5) removing the steel rope. In the startup process, the internal pressure sizing is adopted, a traction tube is saved, the welding is avoided, waste products in the startup process are reduced, and the success rate is high.

Description

Technical field: [0001] The invention relates to a straight-wall pipe manufacturing tooling, in particular to a PE straight-wall pipe start-up forming and traction device and a method for realizing traction by the device. Background technique: [0002] When producing large-diameter PE straight-wall pipes, traditional start-up forming and pulling devices such as figure 1 As shown, it is mainly composed of tractor 1, traction pipe 5, cooling sizing water tank 2, sizing sleeve 3 and extrusion die 4 (the specific installation relationship between them is a technology well known to those skilled in the art, and will not be repeated here. ). The overall length of the device is about 35 meters, and its starting mode must be put into a traction tube 5 about 30 meters long, and the outer diameter of the traction tube 5 is identical with the pipe to be produced. When starting up, the pipe blank 6 extruded from the extrusion die 4 is connected to the traction pipe by hot-melt welding...

AI Technical Summary

Problems solved by technology

Since each traction tube is 30m long, the tube is manually put in during operation, which requires an extra 30m of space in the production workshop as the operating space for the traction tube, which takes up a lot of space

[0010] 2. It is time-consuming and labor-intensive to put in the traction tube when starting up. Generally, it takes 3-4 people to prepare before starting up, and it takes more than two hours to put in the traction tube;

[0011] 3. The welding of the tube blank and the traction tube is not easy to succeed at one time. Even a slight poor welding or air leakage will cause startup failure or unnecessary waste (air leakage will cause insufficient vacuum and cause the outer diameter of the pipe to be out of round);

[0012] 4. In order to ensure reliable welding, it takes a long time to extrude the material when starting up, until the temperature of the extruded tube blank is very high, and welding can only be done when the plasticization is complete, which takes time and materials to start up

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