Welding method of PVC plastic pipe

Update:19 Jan 2020

With the expansion of the application of plastic pipes, […]

With the expansion of the application of plastic pipes, the variety of plastic pipes has also increased. Now in addition to ordinary PVC and polyethylene pipes, there are: PVC core-layer foamed pipes, PVC, PE double-wall corrugated pipes, aluminum-plastic composite pipes, Cross-linked PE pipe, plastic steel composite pipe, polyethylene silicon core pipe, etc.

The connection methods of plastic pipes are: mechanical connection, hot-melt socket welding, hot-melt butt welding, and spot welding. Among them, hot melt butt welding and spot welding are the main connection methods of plastic pipes.

Hot melt welding

In the case of hot melt butt welding, the inner and outer surfaces of the heating tool are used to heat the corresponding outer and inner surfaces of the welded plastic pipe and pipe, respectively, so that it melts, quickly pull out the heating tool, and then quickly insert the pipe. The pipe is applied with a certain amount of force to achieve the purpose of welding after cooling. General hot melt butt welding is suitable for projects with a diameter of less than 125mm.

Hot melt butt welding

Hot melt butt welding is to use a hot melt butt welder to heat the welding end faces of two pipes (which must be cleaned or milled before welding) to a certain temperature, when they melt, then quickly attach them, and apply a certain pressure until cooling, This welds the two pipes together.

According to the contact method of the welding machine heating plate and the pipe being welded, it can be divided into contact heating and infrared radiation heating. When welded in accordance with the appropriate process, the tensile strength and pressure resistance of the Hankou area are comparable to or stronger than the pipe itself. Hot melt butt welding is suitable for welding of plastic pipes with a diameter greater than 90mm. It should be noted that it is strictly forbidden to be impacted by external force during the welding process to sufficient cooling, nor can it be forced to cool by any method.

Electrofusion welding

The electric fusion welding of plastic pipes uses electric wires on the inner surface of the electric fusion pipe to heat them, so that the inner surface of the pipe and the outer surface of the pipe are melted. Due to the thermal expansion effect of the plastic welded pipe, the plastic pipe and its connector are fused in Together, and then cooled to the required time to achieve the purpose of welding.

Welding area should also be cleaned or scraped before welding, mainly to remove the 0.1-0.3mm oxide layer. Select the appropriate welding parameters according to the material, that is, control the heating time and heating voltage or current to ensure that the temperature and pressure of the molten plastic reach a suitable value. Thus, high-quality plastic welded joints are obtained.