Thermal contracting directional memory polyvinyl chloride pipe and manufacture thereof

Abstract

A polyvinyl chloride pipe with radial and / or longitudinal thermal directional shrinking memory function is prepared from polyvinyl chloride through shaping pipe, blocking both ends, arranging it in a limiter, filling high-pressure air in while heating it for expansion, cooling and releasing pressure.

Description

technical field

[0001] The invention relates to the field of materials, in particular to a polyvinyl chloride pipe with thermal shrinkage orientation memory, and also provides a manufacturing method of the polyvinyl chloride pipe. technical background

[0002] Thermal shrinkage memory of polymer materials has been applied in many occasions. For example, two materials (steel and plastic) with different thermal expansion coefficients (steel and plastic) can be fixed and compounded by using thermal shrinkage memory. It can effectively prevent heat delamination during use. It is especially advantageous in pipe compounding. However, the existing heat-shrinkable materials are usually made of polyethylene, and they need to be irradiated with high-intensity rays to form memory. As described in Chinese patent 00122353.4, heat-shrinkable pipe fittings are made with polyethylene additives as raw materials. The pipe fittings are cross-linked and modified by gamma ray irradiation. Beca...

Examples

Embodiment 1

[0013] Embodiment 1, radial heat shrinkable directional memory polyvinyl chloride pipe, the manufacturing method is first to extrude the polyvinyl chloride pipe, the two ends of the pipe are blocked, and a metal pipe with a diameter larger than the pipe material and a number of through holes is set on the radial pipe wall. Tube, the vertical length of the metal tube is the sum of the length of the tube, the length of the resistance head and the length of the air valve, which means that there is no room for longitudinal extension of the tube, fix the limit tube, soak it in a water bath at about 100°C to soften it, and inflate the tube while soaking , expanding the tube while softening, quenching to room temperature for setting, degassing and decompression, and withdrawing from the limiting tube.

Embodiment 2

[0014] Embodiment 2, longitudinal heat-shrinkable directional memory polyvinyl chloride pipe, the manufacturing method is to first extrude the polyvinyl chloride pipe with anti-aging agent, the two ends of the pipe are blocked, and the inner diameter of the ferrule is equal to the outer diameter of the pipe and radial A number of metal tubes with through-holes are set on the tube wall. The longitudinal length of the metal tube is greater than the control value of the tube length. Heat and soften in a water bath at about ℃, then cool the expanded tube to room temperature, release the pressure in the tube, and exit the limiting tube.

Embodiment 3

[0015] Embodiment 3, with reference to Examples 1 and 2, change the length and inner diameter of the limit metal pipe, and use the same method to manufacture a directional memory polyvinyl chloride pipe with shrinkage in the radial and longitudinal directions, wherein the formed polyvinyl chloride pipe When adding external additives such as antifungal agents and flame retardants, the plastic pipe is first softened with an oil bath at 110°C, then pressurized and expanded, cooled to room temperature and shaped, and the limiting metal pipe is removed after depressurization.

technical field

[0001] The invention relates to the field of materials, in particular to a polyvinyl chloride pipe with thermal shrinkage orientation memory, and also provides a manufacturing method of the polyvinyl chloride pipe. technical background

[0002] Thermal shrinkage memory of polymer materials has been applied in many occasions. For example, two materials (steel and plastic) with different thermal expansion coefficients (steel and plastic) can be fixed and compounded by using thermal shrinkage memory. It can effectively prevent heat delamination during use. It is especially advantageous in pipe compounding. However, the existing heat-shrinkable materials are usually made of polyethylene, and they need to be irradiated with high-intensity rays to form memory. As described in Chinese patent 00122353.4, heat-shrinkable pipe fittings are made with polyethylene additives as raw materials. The pipe fittings are cross-linked and modified by gamma ray irradiation. Beca...

Examples

Embodiment 1

[0013] Embodiment 1, radial heat shrinkable directional memory polyvinyl chloride pipe, the manufacturing method is first to extrude the polyvinyl chloride pipe, the two ends of the pipe are blocked, and a metal pipe with a diameter larger than the pipe material and a number of through holes is set on the radial pipe wall. Tube, the vertical length of the metal tube is the sum of the length of the tube, the length of the resistance head and the length of the air valve, which means that there is no room for longitudinal extension of the tube, fix the limit tube, soak it in a water bath at about 100°C to soften it, and inflate the tube while soaking , expanding the tube while softening, quenching to room temperature for setting, degassing and decompression, and withdrawing from the limiting tube.

Embodiment 2

[0014] Embodiment 2, longitudinal heat-shrinkable directional memory polyvinyl chloride pipe, the manufacturing method is to first extrude the polyvinyl chloride pipe with anti-aging agent, the two ends of the pipe are blocked, and the inner diameter of the ferrule is equal to the outer diameter of the pipe and radial A number of metal tubes with through-holes are set on the tube wall. The longitudinal length of the metal tube is greater than the control value of the tube length. Heat and soften in a water bath at about ℃, then cool the expanded tube to room temperature, release the pressure in the tube, and exit the limiting tube.

Embodiment 3

[0015] Embodiment 3, with reference to Examples 1 and 2, change the length and inner diameter of the limit metal pipe, and use the same method to manufacture a directional memory polyvinyl chloride pipe with shrinkage in the radial and longitudinal directions, wherein the formed polyvinyl chloride pipe When adding external additives such as antifungal agents and flame retardants, the plastic pipe is first softened with an oil bath at 110°C, then pressurized and expanded, cooled to room temperature and shaped, and the limiting metal pipe is removed after depressurization.