SJ film blowing machine may encounter various faults during use. The following are some common faults, causes and solutions:
1. Unstable film bubble
Cause:
The molten film is stretched too fast or the pressure changes during the solidification process, resulting in pressure fluctuations inside the film bubble.
The improper position of the cooling air ring or insufficient cooling efficiency cannot stably support the film bubble.
The plasticizing temperature is too high or too low, affecting the fluidity and stability of the melt.
The extruder extrusion volume is unstable, resulting in fluctuations in the thickness and width of the film bubble.
Solution:
Adjust the extrusion volume and traction speed of the extruder to stabilize the condensation line of the film bubble.
Adjust the position and cooling efficiency of the cooling air ring to ensure stable support of the film bubble from the bottom.
Appropriately reduce or increase the plasticizing temperature to optimize the fluidity and stability of the melt.
Check and adjust the feeding system and screw speed of the extruder to ensure stable extrusion volume.
2. Unsmooth discharge
Causes:
Improper die temperature control leads to blockage of the discharge port.
Improper die gap adjustment or uneven mold heating causes uneven discharge.
Impurities mixed in the raw materials or inappropriate formulations affect the fluidity of the melt.
The barrel screw is severely worn or the speed is too fast, resulting in poor plasticization effect.
Solutions:
Reasonably adjust the die temperature to ensure smooth discharge.
Calibrate the die gap, check and solve the problem of uneven temperature.
Ensure the purity of the raw materials, clean the die and barrel screw, and adjust the appropriate formula.
Replace the barrel screw that is severely worn, or reduce the screw speed to ensure that the raw materials are fully plasticized.
3. Other common faults and solutions
Poor film opening
Causes: The barrel screw or mold temperature is too high; the traction roller pressure is too high; the raw material selection or additives are improperly used.
Solutions: Increase the power of the cooling fan; appropriately relax the traction roller pressure; re-select the raw materials and reasonably allocate the additives.
Uneven winding
Causes: uneven film thickness; insufficient or uneven cooling; uneven pressure of the traction roller.
Solutions: adjust the thickness of the film; adjust the air volume of the cooling air ring; adjust the pressure of the traction roller.
Bubble rupture or breakage
Causes: too many impurities in the raw material; the plasticizing temperature is too low or improperly set; the traction speed is too fast.
Solutions: replace the raw material or replace the filter; increase the plasticizing temperature and set a reasonable temperature curve; appropriately reduce the traction speed.
Wrinkled film
Causes: uneven film thickness; too high plasticizing temperature; uneven clamping force of the traction roller.
Solutions: adjust the uniformity of film thickness; reduce the plasticizing temperature and improve the cooling efficiency; appropriately adjust the clamping force and make the pressure uniform.
