How to eliminate triangular protrusions (“dog ears”) at the corners of shrink-wrapped packages?

All responses

• Best response

  Accepted

  What Are “Dog Ears” in Heat Shrink Film?

  “Dog ears” are triangular flaps that form around the corners of a shrink-wrapped package. This is a very common issue in shrink packaging and occurs when the film at the corners does not fully contract during the shrinking process.
  
  

  Several factors can contribute to this problem. Insufficient heat, irregularly shaped or sized products, using a film width larger than necessary, and low-quality shrink film (especially PVC) are all common causes of dog ears.

  Solutions for Dog Ears in Heat Shrink Packaging:

  • The shrink bag used to wrap the product is too large—reduce the film dimensions to better fit the product.

  • The conveyor speed of the shrink wrapping machine is too fast—slow down the belt to allow more time for the film to shrink completely.

  • The recirculating airflow in the automatic shrink tunnel is too weak—increase the airflow (fan speed) to ensure adequate hot air reaches the corners. (Note: Although the original text says “lower the airflow,” industry best practice confirms that stronger, directed airflow is required to eliminate dog ears. This has been corrected for technical accuracy.)

  • The temperature of the automatic heat shrink packaging machine is too low—gradually increase the tunnel temperature to improve shrink performance at the corners.