Stretch wrap is usually made of linear low-density polyethylene or LLDPE. 

There is one method of producing it in our company:

 

-----Cast, where the film is passed over cooling rollers, which considerably speeds up the cooling process. Because the film is made in piltiple layers, It costs less to produce than blown ones. The layers allow the film to be made with cling properties on one side, which is perfect if you don’t want one pallet to stick to the one next to it. The layers also make the film stronger with the addition of tough layers on the inside.

 

Most of what’s commercially available nowadays is cast, Stretch Wrap film, which is clearer and quieter release than blown ones when coming off the roll.