Troubleshooting Top 4 POF Shrink Film Issues in Packaging

Solve common POF shrink film problems like burn-through, uneven shrinkage, condensation fog, and sealing blade sticking to improve your packaging yield.

Introduction:
POF shrink film is an eco-friendly and highly transparent material favored for wrapping a wide array of products. Its excellent shrinkage properties ensure a tight, secure package. However, because it relies on heat to shrink and seal, operators often face thermal-related issues that compromise the final appearance and packaging integrity.

Problem 1: Holes or burn-through after shrinking
Cause: The temperature in the shrink tunnel is too high, or the conveyor speed is too slow, causing localized overheating.
Solution: Lower the shrink tunnel temperature (POF typically shrinks optimally between 120°C and 140°C) and increase the conveyor belt speed slightly. Ensure the hot air circulation is uniform and the film is not lingering too long in the heat zone.

Problem 2: Uneven shrinkage or wrinkled surface
Cause: Uneven heat distribution in the tunnel or insufficient cross-linking in the film's molecular structure.
Solution: Service the shrink tunnel to ensure consistent airflow and heating. Choose a high-quality cross-linked POF film, which provides balanced shrinkage in both machine direction (MD) and transverse direction (TD), resulting in a smooth, tight finish.

Problem 3: Condensation fog forming inside the package
Cause: Moisture evaporating from the product (especially food) condenses on the inside of the film due to temperature changes.
Solution: Use POF film infused with anti-fog additives. These additives lower the surface tension, allowing the moisture to form a continuous clear film and flow down the sides rather than forming opaque droplets that obscure the product.

Problem 4: The film sticks to the sealing blade
Cause: The sealing temperature is set too high for the film's outer layer, or there is a lack of proper insulation on the sealing jaw.
Solution: Reduce the heat sealing temperature and dwell time. Apply a high-quality Teflon (PTFE) coating to the sealing blades to prevent molten film from adhering to the metal. Regular cleaning of the blades also helps maintain a clean seal.