Shrink wrap comes in a variety of thicknesses, clarity, strengths, and shrink ratios. The most commonly used type of shrink wrap is polyolefin shrink film. The other type of shrink films include PVC (polyvinyl chloride), which is a cheaper quality shrink film-less expensive shrink but has a smaller shrink force. PVC shrink film is a very popular with CD and DVD packaging, package boxes, software, and other non-edible food products.
On the other hand, polyolefin film is more commonly used with food products, gift baskets, and bundling multiple products together. Polyolefin wrap is also more pliable than PVC film and does not tear as easily. Poly film also emits very little to no odor and as aforementioned, it is safe to use with food.
The biggest difference is that Polyolefin Shrink Film ages a lot better than PVC shrink wrap in the long run. Poly film does not become brittle or discolored (yellow) with age and does not have a tendency to break down during the heat sealing process phase of the packaging. PVC shrink wrap create order and smoke and the sealing equipment and carbon build up called film deposits. This does not happen with poly film which means less maintenance and a cleaner, higher quality appearance.
The reason polyolefin is better quality has to do with that poly film is a polymer-a large macromolecule composed of repeating structural units-for poly film its ethylene. On the other hand, PVC is also a polymer (vinyl polymer) constructed of repeating vinyl groups.