Troubleshooting of the most popular polypropylene

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Troubleshooting of polypropylene blown film molding fault

1. The longitudinal thickness needs to define 'in which aspects performance should be considered first to minimize complexity'

fault analysis and Troubleshooting:

(L) the amount of air cooling ring blowing is too large. The blowing volume should be appropriately reduced. This situation often occurs when the film width is narrow and the traction speed is fast. At this time, the expansion part of the film tube exceeds the edge of the inlet of the water cooling ring. Due to excessive air blowing, uneven water flow causes intermittent changes in the film thickness along the longitudinal direction

(2) there is too much water supply for water cooling ring. Water supply should be reduced appropriately. When the water level of the water cooling ring is higher than the top of the ring, it will also cause uneven flow. Therefore, the water supply cannot be too much,

(3) the air cooling ring is too close to the machine head. It often occurs when the width of the film is narrow. At this time, 8. The digital display spring testing machine has two-stage limit protection: program-controlled and mechanical. The distance between the air cooling ring and the water tank is too large, and the pressure of the air cooling ring does not work. The result is equivalent to too much air blowing. In this regard, the water cooling ring should be appropriately raised and the position of the air cooling ring should be lowered

(4) the distance between the water cooling ring and the machine head is too large, resulting in uneven thickness of the pre cooled bubble tube which still sags by its own weight. In this regard, the distance between the water cooling ring and the machine head should be shortened, so that 7. The speed range: 0.05 ~ 500mm/min is not more than 300mm, generally 250mm~300mm is appropriate

(5) the discharge of the machine head is unstable. Check whether the feeding is normal and whether the temperature at the bottom of the hopper is too high

(6) filter blockage. Replace the filter

(7) if the winding speed is uneven, the driving devices of winding and other pinch rolls should be repaired to make the winding speed stable and uniform

(8) there is foreign matter attached on the surface of the film clamping roller. Foreign matters should be removed

(9) the water-cooled ring is not concentric with the machine head. The alignment should be recalibrated


l0) the blowing ratio is too small. It should be increased appropriately. The blowing ratio of polypropylene blown film is generally 1: (1~2) and the maximum is not more than 1:2.5

2. The transverse thickness is uneven

so the zero adjustment screw can be adjusted upward. Analysis and troubleshooting methods:

(1) the die gap of the machine head is uneven: the die gap should be adjusted appropriately

(2) the positions of the air cooling ring and the water cooling ring are set improperly. The positions of the air cooling ring and the water cooling ring should be adjusted appropriately to make the bubble shape even and straight. The parts with thin film can be slightly close to the water cooling ring

(3) uneven die temperature. Check whether the die heater is damaged and avoid blowing cooling air onto the die

(4) uneven air blowing of air cooling ring. It should be adjusted evenly

(5) there are obstructions in the die. The die shall be cleaned. (end)

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