Shrink Wrap or Shrink Film

Shrink Wrap or Shrink Film (See shrink machinery, below)

Shrink film falls into a variety of categories and price ranges.

At the lower cost end is common polyethylene shrink film, used in bundling applications such as in the soft drink industry, bulk bundling of industrial and some retail products, and bundling of some printed books (such as phone books. This film is very inexpensive, tends to be of a heavier gauge (typically 1.0 mils and up) and requires appropriate equipment to accomplish the shrinking.

At the higher cost range are films known under the general term of polyolefin. Polyolefin films come in an assortment of different layers, made up of various plastics. Films can be specialized to resist tearing, control zippering, reduce amount of shrink, and to create other desired characteristics. Polyolefin films come flat and center-folded for use in various types of machines. See below for machine descriptions.

PVC film is a higher cost film used in some specialized applications. In particular, it is noted for its very low shrink force, thus allowing it to work well on flimsy packages. For example, it can be used to wrap a few sheets of paper without the paper curling up while the film is shrinking.

Shrink Wrap Machines

Center-folded films are applied to packages with an L-sealer and shrink tunnel. The L-Sealer is named for the L-shape of the two sealing components. When the L-bar is pulled down, it makes a seal on two sides of the center-folded film. The third side is sealed as a result of the previous package sealing. The fourth side is the center-fold, and therefore does not require sealing. L-Sealers and tunnel combinations are commonly available in a wide assortment of sizes and automation levels. L-sealers lend themselves for situations when package sizes vary somewhat, when high speed is not essential and

Flat shrink films are applied by machines which form the film around a custom designed film plough. This method lends itself only to long runs of same-sized packages where high speed is important.