What’s the Difference between a Stretch Wrapper and a Shrink Wrapper?

What’s the Difference between a Stretch Wrapper and a Shrink Wrapper?

One of the most commonly misused terms for a stretch wrapper is a shrink wrapper. Often, people that use stretch wrappers refer to them as shrink wrappers. The ironic thing is that the two machines looks nothing alike and the functions they perform do not provide the same result.

The purpose of a shrink wrap machine is to apply heat to a polymer plastic film that shrinks to the product that it’s covering. This is normally done with some sort of heat gun or hand-held device and sometimes done with larger shrink wrap systems that are about the size of an office desk. When shrinking film to the product it’s normally used to encase packs of or individual products. An example would be shrink wrapping a book so it looks like new when purchased or boxes of cereal to a cardboard container to package them together. Rarely is it used to secure product together on a pallet for transportation purposes.  That’s really where a stretch wrap machine comes in.

A stretch wrapper is used to secure multiple products that are normally cased or boxed and secure them to a uniform position on a pallet. This is done by applying tension to stretchable film and applying that film tightly to the product on a pallet. There is no heat or shrinking of the material involved. The most common way this is done is with a semi-automatic turntable style stretch wrap machine. In this process a pallet with product stacked in uniform position is placed on a turntable. The turntable then spins around in circles while stretch wrap film is attached to the load. The stretch film is tightened either by mechanical tension or electronic tension and the film is raised up and down on a carriage so that the entire pallet can be “wrapped” with film. This secures the load tightly so that in transportation, the load arrives intact. This same result can be accomplished with a rotary arm stretch wrapper. With a rotary arm stretch wrapper, there is no turntable, so the product stays in place on the pallet. A rotary arm then circles the pallet with the film that is being stretched around the product.

 

Stretch Wrap Machine (think pallet loads of boxes)                            Shrink Wrapper (think heat sealed individual items, like pizzas!)