Stretch wrap, often known as stretch film, is a highly flexible plastic material used to wrap goods. The objects are kept tightly bound by the elastic recovery. Shrink wrap, on the other hand, is put loosely around an item and shrinks firmly when heated. While it resembles plastic food wrap in appearance, it is not typically composed of food-safe materials.
It's commonly used to unitize pallet loads, but it can also be used to bundle smaller goods together. Bundling stretch film, hand stretch film, extended core stretch film, machine stretch film, and static dissipative film are all examples of stretch film.
LLDPE, or linear low-density polyethylene, is the most prevalent stretch wrap material. It is made by copolymerizing ethylene with alpha-olefins, the most prevalent of which are butene, hexene, and octene. Stretch film properties are improved when higher alpha-olefins (hexene or octene) are used, especially in terms of elongation at break and puncture resistance. Other polyethylene and PVC materials can also be used. Many films have a 500 percent stretch at break but only 100 to 300 percent stretch when in use. The elastic recovery is employed to maintain the load tight once it has been stretched.
Stretch wrap can be made in one of two ways. 1) Air-cooled blown resin: the resin is melted and extruded via an annular die. This is a more time-consuming process, but it ensures superior quality in all of the areas outlined below. Because of the quantity that may be produced every hour, the cost of production is likewise higher. 2) Extrusion: the film is extruded via a slot die and then cooled by rollers. This speeds up the cooling process. The quality isn't as good as blown glass, but more can be made in an hour for less money.