Why Does Shrink Wrapping Film Shrink

Be it a shrink wrapped video game, music CD or a magazine, the process of wrapping these products in their clear protective cover can be done simply by using one of our chamber shrink wrapping machines from Minipack Torre.

All heat shrink wrapping films are made from one polymer or another so let’s take one molecule of this polymer and look at it before it goes through the process of making shrink wrapping film. If we compare one molecule of film to a piece of string. imagine that you have 1000 single balls of string all in one big mess.  By working the polymers when blowing the PVC or Polyolefin into a big bubble, all of these messy balls of coiled up strings stretch and line up all in order giving you a clear flat material  when cooled quickly, the molecules stay lined up perfectly straight.  This material can now be made into bags and centre folded shrink wrapping film just like we use on our Heat shrink wrap machines.

Our film is now formed into a clear flat material, however If we apply heat, then these polymers soften and it will retract back to their original state, shrinking in size. This is called the softening point. What these shrink wrap films do is convert the energy from the heat applied into the force required to to enable it to recoil or retract back to how it was. This is the reason why if used and selected correctly very little heat from the shrink wrapping process transfers into the shrink wrapped product.  

Dan packaging machinery have a full range of shrink wrapping machines from Minipack Torre and a fantastic range of center fold shrink wrapping films in PVC and Polyolefin from Darnell so why not visit us at Dan Packaging.

Posted by Steve Holt

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