Finished Shrink Wrap Problems: Crow's Feet Wrinkles
Effect: Wrinkles otherwise known as Crow's feet in the shrink film industry, can be seen weaving their way down from corners or edges of the finished shrink film wrapper.
These wrinkles or Crow's feet, like dog ears, are a common occurrence but more likely experienced by those who have recently started using a new machine. As detailed on the dog ears problem section, the heat vacuum used within shrink wrapping can only be finely tuned so much.
However there are reasons why shrink film wrinkles will show more than they should, and they certainly should not be as prevalent as dog ears are on rounded packaging. Below are a few reasons why you may be witnessing Crow's feet and how to lessen wrinkles.
- The reasons for Crow's feet and Dog ears can be similar, so if you correct one you may solve the other. Use a smaller size of shrink film, thinner micron of film or higher quality Polyolefin.
- Your tunnel or chamber not only uses a heat vacuum to seal but if utilising a conveyor system, motion also. So not only do you need to test the heat settings and that the vacuum is performing correctly, but the speed with which the item is moving may need to be slowed down or increased.
- Dog ears and wrinkles are common place when shrink wrapping products which are not straight edged. Unfortunately shrink film has no option but to fold in on itself when there isn't a surface to bond to.
- The thinner the micron the lesser visible this will be. Hence why circular exterior packaging suffers the most from winkles and dog ears when wrapped.