Usage of hot melt butt welding machine

1. Welding preparation
Welding preparation is mainly to check whether the hot melt welding machine is in good condition. For example, check whether the fasteners at various parts of the machine and tools fall or become loose; Check whether the electrical circuit of the whole machine is connected correctly and firmly; Check whether the hydraulic oil in the hydraulic box is sufficient; Acknowledge that the power supply matches the input requirements of machines and tools; Whether the heating plate meets the requirements (whether the coating is damaged); Commissioning of milling cutter and oil pump switch, etc.
Then install the slips with consistent pipe specifications into the rack; Set the temperature of the heating plate to the welding temperature (the welding temperature of the polyethylene pipe is 200~230 ℃). Before heating, scrub the surface of the heating plate with soft paper or cloth dipped in alcohol, but be careful not to scratch the PTFE anti sticking layer.
2. Welding
Welding shall be carried out according to the parameters of the welding procedure card. If necessary, it shall be properly adjusted according to changes in weather, ambient temperature, etc. The main steps are as follows.
(1) Use a clean cloth to remove the dirt at both pipe ends. Place the pipe in the frame slip so that the length of the two ends extending out is equal (it should be as short as possible under the condition of satisfying the requirements of milling and heating, usually 25~30mm). If necessary, the parts outside the pipe rack shall be lifted with supports to make the pipe axis and the center line of the rack at the same height, and then fastened with slips.
(2) Put in the milling cutter, first turn on the milling cutter power switch, then slowly close the welding ends of the two pipes, and apply appropriate pressure until there are connected chips at both ends. Remove the pressure, wait for a moment, and then exit the movable frame and turn off the milling cutter power. The chip thickness shall be 0.5~1.0mm, and the height of the adjusted milling insert can adjust the chip thickness.
(3) Take out the milling cutter, close the two pipe ends, and check the alignment of the two ends. The displacement of both ends of the pipe shall not exceed 10% of the pipe wall thickness or the larger value of 1mm, and the straightness and tightness of the pipe can be adjusted to a certain extent; When closing, there is no obvious gap between the two ends of the pipe, and the maximum gap width cannot exceed 0.3mm (DN<225mm) and 0.5mm (225mm400mm). If the above requirements are not satisfied, it shall be milled again until the above requirements are satisfied.
(4) Measure the drag force (friction resistance of moving fixture). This pressure should be superimposed on the process parameter pressure to obtain the actual applied pressure. Check whether the temperature of the heating plate reaches the set value.
(5) After the temperature of the heating plate reaches the set value, put it into the rack and apply regular pressure until the minimum crimping on both sides reaches the regular width and the pressure decreases to the regular value (so that the tube end face and the heating plate just keep in contact) for heat absorption.
(6) When the time arrives, retract the movable frame, quickly take out the heating plate, and then close the two pipe ends. The switching time should be as short as possible and should not exceed the regular value. After cooling to a regular time, relieve the pressure, loosen the slips, and take out the connected pipes.
The welding machine is characterized by:
① The best welding parameters of pipes with different materials, diameters and SDRs have been set in advance;
② Fully active control of welding time, temperature and pressure;
③ Active detection and compensation of towing pressure;
④ The heating plate is ejected actively to minimize the temperature loss;
⑤ Active monitoring and prompt of the whole process of each operation step in the welding process;
⑥ The rapid clamping system improves the operation efficiency by 30%;
⑦ The dynamic data of the welding process can be printed or downloaded to the PC of the quality inspector through the data transmission system, so as to recheck the on-site performance of the welder and operator;
⑧ The database can store up to 600 interface related welding parameters.