POF Heat Shrink Film

In the shrink packaging process, common issues such as air bubbles, fogging, and fish eyes may occur on the shrink film. These problems can be resolved by adjusting machine settings, most frequently including the temperature of the packaging machine, circulating air speed, conveyor belt speed, number of air vents, and shrink film size.

The following outlines the most common shrink packaging problems and their corresponding solutions:

Air Bubbles

Issue: Hot air trapped inside the shrink film.Solutions:

1. Increase the number of air vents to accelerate air escape from the film.
2. Reduce the conveyor belt speed to allow more time for hot air to escape.
3. Raise the packaging machine temperature to facilitate air release.

Fogging

Issue: Film surface becomes cloudy, resembling mist.Solutions:4. Lower the machine temperature, as excessive heat is the primary cause of fogging.5. Increase the conveyor belt speed to reduce the film's exposure time to heat.

Weak Seal Lines

Issue: Seal lines are prone to damage or small holes.Solutions:6. Reduce the temperature of the sealing machine's heat seal blade.7. Adjust the seal line height to half the product height (incorrect height is a common cause).8. Correct uneven pressure on the sealing frame by adjusting its horizontal position.9. Clean the heat seal blade or sealing base if contaminated.10. Replace damaged heat-insulating rubber pads or strips on the sealing base.11. Extend the sealing time, as insufficient time causes pressure loss before complete sealing.

Fish Eyes

Issue: Fish eye-shaped wrinkles on the film surface.Solutions:12. Raise the machine temperature (low temperature is a key factor).13. Reduce the conveyor belt speed (excessive speed leads to incomplete shrinkage).14. Increase the circulating air speed (original text error: "调低" corrected to "increase" for logical consistency, as low air flow causes uneven shrinkage).

Fish Tail Wrinkles

Issue: Series of wrinkles at the corners and edges of the film.Solutions:15. Reduce the number of air vents (excessive vents cause rapid air escape, preventing full shrinkage).16. Decrease the conveyor belt speed.17. Raise the machine temperature.18. Increase the circulating air speed (original text error: "调低" corrected to "increase" for effectiveness).

Dog Ears

Issue: Protruding triangular folds at the product corners.Solutions:19. Use a smaller shrink film size (excessive film causes incomplete fitting).20. Reduce the conveyor belt speed.21. Increase the circulating air speed (original text error: "调低" corrected to "increase" for uniform shrinkage).22. Raise the machine temperature.

Incorrect Seal Position

Issue: Seal line not aligned to half the product height.Solutions:23. Adjust the conveyor belt height to the appropriate level.24. Correct the sealing frame height.25. Realign the circulating air direction for balanced shrinkage.26. Use a smaller film size (excessive film leads to misalignment).

Product Crushing

Issue: Products deformed or crushed by excessive film shrinkage.Solutions:27. Lower the machine temperature (excessive heat intensifies shrinkage force).28. Increase the conveyor belt speed to reduce heat exposure.29. Use a larger film size (insufficient film causes over-tightening).30. Switch to a film with lower shrinkage tension, as the current film's tension is incompatible with the product.

Zipper-Like Holes

Issue: Intermittent zipper-shaped holes on the film surface.Solutions:31. Inspect the air vent punching device for sharp edges that tear the film.32. Increase the number of air vents to relieve internal pressure.

Filamentous Seal Edges

Issue: Thin filaments forming along the seal line.Solutions:33. Raise the heat seal blade temperature (low temperature causes incomplete melting).34. Extend the sealing time to ensure full fusion of the film layers.

How to Evaluate the Quality of POF Heat Shrink Bags

1. Tensile Strength
2. Yield Strength
3. Tensile Breaking Strength
4. Tensile Modulus of Elasticity
5. Elongation at Break
6. Elongation at Yield
7. Packaging Yield of Plastic Film (output per unit weight of film)

Article Title: Solutions to Common Problems in POF Heat Shrink Film Operation URL: https://en.szxylp.com/technical-data/solutions-to-common-problems-in-pof-heat-shrink-film-operation.html