Stretch packaging, also known as stretch film, self-adhesive plastic film can be stretched and wrapped tightly to the packaged items, and the self-adhesive will not adhere to the surface of the item is wrapped in batter, only exists in the film and film wall. No heat shrinkage treatment is needed during the packaging process, which is conducive to saving energy, and is also conducive to the identification of highly transparent packaging items, reducing distribution errors.


Stretch film for packaging must have two basic properties. First, it has good mechanical strength, extensibility and resilience. Second, its surface has good viscosity. Polyethylene can provide good mechanical strength, excellent elongation and better resilience for stretch-wrap films. However, it does not provide sufficient surface viscosity. Therefore, polyethylene stretch-wound films require the use of tackifier additives to obtain the surface viscosity of the film.


The viscosity required to stretch the wound film should have good peel viscosity and good lap viscosity. The higher the peel viscosity, the easier the tray is to spread, and the better the sealing performance of the film. The higher the lap viscosity, the smaller the longitudinal displacement of the film. Therefore, in order to obtain a solid package, it is necessary to balance the peel viscosity and lap viscosity of the stretch-wound film.