Welding Methods For Plastic Pipes

With the expansion of the application of plastic pipes, the varieties of plastic pipes are also increasing. Now, in addition to ordinary PVC and polyethylene pipes, there are: PVC core foam pipes, PVC, PE double-wall corrugated pipes, aluminum-plastic composite pipes, cross-linked PE pipes, plastic-steel composite pipes, polyethylene silicon core pipes, etc.
The connection methods of plastic pipes are: mechanical connection, hot melt socket welding, hot melt butt welding, and spot fusion welding. Among them, hot melt butt welding and spot fusion welding are the main connection methods for plastic pipes.
Hot melt socket welding
During hot melt socket welding, the inner and outer ring surfaces of the heating tool are used to heat the corresponding outer and inner ring surfaces of the plastic pipe and pipe fittings to be welded, melt them, quickly pull out the heating tool, and then quickly insert the pipe into the pipe fitting, and apply a certain amount of force, and achieve the purpose of welding after cooling. Generally, hot melt socket welding is suitable for projects with a diameter less than 125mm.
Butt fusion welding
Butt fusion welding is to use a hot fusion welding machine to heat the welding end faces of two pipes (which must be cleaned or milled before welding) to a certain temperature, melt them, and then quickly fit them together, and apply a certain pressure until they cool down, so that the two pipes are welded together.
According to the contact mode between the welding machine heating plate and the welded pipe, it can be divided into contact heating and infrared radiation heating. When welded according to the appropriate process, the tensile strength and pressure resistance of the Hankou part are equivalent to or stronger than the pipe itself. Butt fusion welding is suitable for welding plastic pipes with a diameter greater than 90mm. It should be noted that it is strictly forbidden to be impacted by external forces during the welding process until it is fully cooled, and no method can be used for forced cooling.
Electric fusion welding
Electric fusion welding of plastic pipes uses the electric heating wire on the inner surface of the electric fusion pipe to heat the inner surface of the pipe fitting and the outer surface of the pipe to melt. The plastic pipe and its connector are fused together by the thermal expansion effect of the plastic welded pipe itself, and then cooled to the required time to achieve the purpose of welding.
Before welding, the welding area should also be cleaned or scraped, mainly to remove the 0.1-0.3mm oxide layer. Choose 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 appropriate values, so as to obtain high-quality plastic welding joints.