Plastic pipe welding machine can be mainly divided into two types: plastic welding machine and metal welding machine based on the material. The technologies used include ultrasonic, high frequency, plasma, electric heating, and rotary type.
The plastic pipe hot melt machine is a high-voltage, high-frequency electrical signal generated by an ultrasonic generator that is converted into the same frequency mechanical oscillation by the piezoelectric inverse effect of the transducer. It acts on the plastic product workpiece in the form of audio longitudinal waves, and the friction between the surface and inner molecules of the workpiece causes the temperature transmitted to the interface to rise. When the temperature reaches the melting point of the workpiece itself, the workpiece interface quickly melts and fills the gap between the interfaces. When the vibration stops, the workpiece cools and solidifies under a certain pressure, achieving a perfect welding result.
The key to welding with plastic pipe welding machine is the hot melt butt joint, which should always be carried out under hot melt pressure. Due to the poor thermal conductivity of plastic materials, the cooling speed is correspondingly slow. The shrinkage of the welding seam material and the formation process of the structure proceed at a slow speed over a long period of time. Therefore, the cooling of the welding seam must be carried out under a certain pressure.
(1) The appearance of the welding seam should be uniform, and the surface of the welding seam and its heat-affected zone should not have any cracks, lack of fusion, pores, slag inclusion, spatter, or fixture welding points.
(2) The surface of the weld should not be lower than the surface of the base material. The weld height should generally not exceed 2mm, and should not exceed 3mm locally. When the height exceeds 3mm, it should be polished and smoothly transitioned with the base material, but must not damage the base material.
(3) The width of the welding seam surface on each side should be 0.5-2mm wider than the groove surface.
(4) The maximum size of the undercut should meet the regulations.
For the preparation work before welding with plastic pipe welding machine: Before welding downwards, the downward welding and defect repairing process specifications should be formulated according to the welding process evaluation. The welding personnel participating in pipeline construction must hold valid welding qualifications. The surface of the oil, floating rust, water, sand, slag after gas cutting, oxide skin, and other impurities on both sides of the groove within 50mm should be cleaned before pipeline welding, and the inside of both sides of the groove should be free of burrs. The dimensions of the pipe ends should be inspected as required.
