Ordinary PE is HDPE, and cross-linked PE is a plastic that melt-blends a silane mixture (containing peroxide) and HDPE in a twin-screw extruder.
The extrusion process parameters are as follows: The temperature of the outer extruder is 160-170°C (near the feed port), 190-200°C, 200-210°C, 220-230°C.
The temperature of the inner extruder was 160-170°C (near the feeding port), 190-200°C, 200-210°C, 220-230°C. Extruder temperature in turn
It is 130-140°C (closer to the feeding port 180-190°C, 200-210°C, 220-230°C. The inner tube inflation pressure is 0.4-0.6 MPa, and the pulling speed is 3-12 m/min.
Abnormal phenomenon in the production of aluminum-plastic composite pipe, analysis of the causes and solutions:
Abnormal phenomenon: Extrusion layering of HDPE and aluminum tape.
Analysis of reasons: The amount of hot-melt adhesive extrusion is too small, the temperature of hot-melt adhesive is too low, HDPE extrusion temperature is too high or too low, and aluminum tape is contaminated.
Solution: Adjust the amount of hot-melt adhesive extrusion, adjust the extrusion temperature of the hot-melt adhesive, adjust the HDPE extrusion temperature, remove the aluminum tape contamination;
Abnormal: fish scales on the outer surface of the composite pipe.
Analysis of the reasons: The extrusion of the outer layer is too small, the extrusion temperature of the outer layer is too low, and there is accumulation of material at the die.
Solution: Increase the amount of extrusion of the outer layer, increase the extrusion temperature of the outer layer, and clean the die.
Abnormal phenomenon: the composite pipe is not round, or the outer diameter is too large;
Analysis of the causes: Excessive extrusion of outer layer material, too low traction speed, and uneven temperature around the die.
Solution: Reduce the amount of extrusion of the outer layer, adjust the pulling speed, and adjust the temperature of the die to make it uniform.
Abnormal phenomenon: sudden burst of composite pipe
Analysis of causes: Insufficient welding head pressure, high compressed air pressure;
Solution: Increase the pressure of the welding head and compress the air pressure appropriately.
Abnormal phenomenon: aluminum ribbon breaks.
Analysis: Aluminum with defects, improper traction or welding
Solution: Exchange aluminum belt adjustment process