Production process of polyvinyl chloride pipe

Abstract

The invention discloses a production process of a polyvinyl chloride pipe. The production process comprises the following steps that A, a steel pipe is fed into a pickling tank for acid pickling work; B, the steel pipe obtained after pickling is thoroughly washed through clear water and dried for use; C, intermediate-frequency heating is carried out on the steel pipe obtained in the step B; D, polyvinyl chloride powder is synchronously sprayed to the inside and outside of the steel pipe through an electrostatic spraying method; E, heating curing is carried out; and F, natural cooling is carried out. Plastic coating work is carried out through an electrostatic spraying line in the step D, and the electrostatic spraying line comprises a steel pipe conveying device, an outer spraying device, an inner spraying device and a powder recycling device. According to the inner spraying device, the work mode that the inner spraying device firstly stretches out of a pipe end, and carries out spraying in the contracting process, and meanwhile dust and chips in the pipe are sucked is adopted. The production process is simple in method and convenient to use; the occupied area of a production line can be reduced, production efficiency can be improved, and the dust and chips in the steel pipe can be synchronously sucked; and a spraying gun is prevented from shaking, powder spraying is even, and the powder utilization rate is high.

Description

Technical field: [0001] The invention relates to the technical field of pipes, in particular to a production process of polyvinyl chloride pipes. Background technique: [0002] The coated pipes of steel pipes include galvanized pipes, aluminum-plated pipes, chrome-plated pipes, aluminized pipes and steel pipes with other alloy layers. Coated tubes include outer coated tubes, inner coated tubes, and inner and outer coated tubes. Commonly used coatings include plastics, epoxy resins, coal tar epoxy resins, and various glass-type anti-corrosion coating materials. The coated steel pipe is made by coating plastic on the inner wall (or outer wall if necessary) by powder fusion spraying technology, and its performance is excellent. Compared with galvanized pipe, it has the advantages of anti-corrosion, no rust, no fouling, smooth and smooth, clean and non-toxic, and long service life. According to tests, the service life of the steel-plastic composite pipe is more than three t...

AI Technical Summary

Problems solved by technology

However, the defects are as follows: 1. The steel pipe is fixed, resulting in uneven outer spraying, that is, the bottom spraying layer is thin. 2. The inner and outer spray guns move from one side to the other side, and then reset; then the next steel pipe can be sprayed. The efficiency is not high, and the powder recycling is insufficient, and the waste of plastic coating powder is serious

3. The movable support is pulled by the steel wire. The defects are as follows. The support is located in the pipe, which is easy to cause scratches on the spraying position. 4. The steel wire rope traction makes the movable support difficult to operate when it is taken out of the pipe end or placed at the starting position of the other end.

5. There are many problems in synchronous heating and curing, because the electromagnetic heating cylinder cannot cover the whole pipeline, and the electromagnetic heating cylinder is constantly moving, resulting in uneven heating and poor curing effect

6. During the storage period of the cleaned steel pipe, it is easy to enter dust, such as dust, iron filings, etc., and accumulate at the bottom of the steel pipe, which will affect the spraying operation. Therefore, it is usually necessary to blow off the dust inside the pipe with a high-pressure air source before proceeding. Electrostatic spraying operation, complex process

[0005] In order to solve the above technical problems, some rigid spray guns have appeared on the market, that is, the spray gun is erected at the end of the steel pipe, the spray gun is pushed forward by the moving trolley, and the track is laid under the moving trolley. However, the length of the spray gun is too long when moving from one end of the pipe to the other end. It leads to vibration at the end and uneven powder spraying. Moreover, the excessively long pipeline will inevitably increase the track distance of the moving trolley supporting the spray gun, increase the occupied area, and greatly reduce the utilization rate of the plant area.

However, reducing the length of the rigid spray gun can not solve the long pipeline (such as more than 8 meters) spraying

Images