Dalian Youyan Plastic Machinery Co., Ltd.
Couplet: Feng Manager
Phone/fax:086-0411-86260347
Hand:18624289888
13604263838
Mail box:21272059@qq.com
Network access:www.dlyouyan.com
Address: Chinese Lushunkou District of Dalian City, the three streams town (take Tuchengzi Dalian to Lushun Road westbound vehicle airport about 200 meters in front of about 100 meters)
The Dalian blown film unit is a key equipment in plastic film production, and its operating status directly affects production efficiency and product quality. However, in practical operation, the blown film unit may encounter various malfunctions, leading to production interruptions or a decrease in product quality.
1. Uneven film thickness
Fault phenomenon: Inconsistent film thickness, resulting in uneven thickness.
Possible reasons:
The uneven temperature of the mold head leads to inconsistent flow of the melt.
The unstable screw speed of the extruder leads to fluctuations in the extrusion volume.
The uneven cooling of the wind ring affects the cooling effect of the film.
The traction speed does not match the extrusion speed.
resolvent:
Check the heating devices in each area of the mold head to ensure uniform temperature.
Adjust the screw speed to ensure stable extrusion volume.
Check the air volume and pressure of the air ring to ensure even cooling.
Adjust the traction speed to match the extrusion speed.
2. There are bubbles or crystal dots on the surface of the film
Fault phenomenon: Bubbles or crystal dots appear on the surface of the film, affecting its appearance and performance.
Possible reasons:
The raw materials contain moisture or impurities.
Improper temperature setting of the extruder resulted in poor plasticization of the melt.
There are carbon deposits or impurities inside the screw or die.
resolvent:
Pre dry the raw materials to remove moisture.
Adjust the temperature settings of each section of the extruder to ensure that the melt is fully plasticized.
Regularly clean the screw and mold head to remove carbon deposits and impurities.
3. The film has fish eyes or stripes
Fault phenomenon: Fish eyes or stripes appear on the surface of the film, affecting its appearance and transparency.
Possible reasons:
The melt temperature is too high or too low, resulting in poor fluidity of the melt.
There are scratches or damages inside the mold head.
The raw materials contain impurities or insufficiently plasticized particles.
resolvent:
Adjust the extruder temperature to ensure that the melt temperature is moderate.
Inspect the interior of the mold head and repair or replace any damaged components.
Use a filter to filter the raw materials and remove impurities.
4. Uneven film winding
Fault phenomenon: The film experiences wrinkles, uneven elasticity, and other issues during the winding process.
Possible reasons:
The tension setting of the traction roller or winding roller is improper.
The uneven thickness of the film results in uneven force during winding.
The neutral deviation of the winding device causes the film to shift.
resolvent:
Adjust the tension of the traction roller and the winding roller to ensure even force distribution on the film.
Check the thickness of the film to ensure its uniformity.
Adjust the centering of the winding device to prevent the film from shifting.
5. Thin film rupture or breakage
Fault phenomenon: The film ruptures or breaks during the blowing process.
Possible reasons:
Excessive melt temperature leads to a decrease in film strength.
The traction speed is too fast, resulting in excessive stretching of the film.
Mold head blockage or insufficient extrusion volume.
resolvent:
Reduce the melt temperature and improve the film strength.
Adjust the traction speed to avoid excessive stretching of the film.
Clean the die head to ensure sufficient extrusion volume.
6. The extruder screw is stuck or difficult to rotate
Fault phenomenon: The extruder screw cannot rotate normally or has difficulty rotating.
Possible reasons:
The raw materials contain metal impurities or other hard substances.
The extruder temperature is too low, causing the melt to solidify.
The screw or barrel is severely worn.
resolvent:
Check the raw materials and remove metal impurities or other hard objects.
Raise the extruder temperature to ensure melt flowability.
Check the wear of the screw and barrel, and replace them if necessary.
7. Poor cooling effect of the air ring
Fault phenomenon: Uneven cooling of the film, resulting in deformation or uneven thickness of the film.
Possible reasons:
Insufficient air volume or unstable air pressure in the wind ring.
The air outlet of the wind ring is blocked or damaged.
The high ambient temperature affects the cooling effect.
resolvent:
Check the air volume and pressure of the air ring to ensure its stability.
Clean the air outlet of the air ring and remove any blockages.
Adjust the ambient temperature and add cooling equipment if necessary.
8. Electrical control system malfunction
Fault phenomenon: The blown film unit cannot start or runs unstably.
Possible reasons:
Unstable power supply voltage or poor contact of power cord.
Electrical components (such as contactors, relays, etc.) are damaged.
PLC or control system program error.
resolvent:
Check the power supply voltage to ensure its stability.
Check electrical components and replace damaged parts.
Restart or reprogram the PLC control system.
9. Excessive noise
Fault phenomenon: Excessive noise during the operation of the blown film unit.
Possible reasons:
Wear or poor lubrication of mechanical components such as gears and bearings.
The clearance between the screw and the barrel is too large, causing friction noise.
The equipment installation is unstable and generates vibration.
resolvent:
Check mechanical components, replace worn parts in a timely manner, and add lubricating oil.
Adjust the gap between the screw and the barrel to reduce friction.
Check the installation of the equipment to ensure its stability.
10. Poor transparency of the film
Fault phenomenon: Low transparency of the film, affecting the appearance quality.
Possible reasons:
Poor quality of raw materials, containing impurities or insufficient plasticization.
Improper temperature setting of the extruder resulted in poor plasticization of the melt.
The cooling speed is too fast or too slow, which affects the crystallization of the thin film.
resolvent:
Use high-quality raw materials to ensure their purity.
Adjust the extruder temperature to ensure that the melt is fully plasticized.
Adjust the cooling rate to ensure even crystallization of the thin film.
The malfunction of the blown film unit may involve multiple aspects such as mechanical, electrical, and raw materials. Operators need to have certain professional knowledge and experience in order to quickly identify problems and take effective measures. Regular maintenance and upkeep of equipment, strictly following operating procedures, can effectively reduce the occurrence of failures and ensure smooth production.
