Why does a heat-shrink film shrink greatly when it is heated? Does the stretched plastic film act as a heat-shrinkable film?
Shrink film in the state of heat, the irregular arrangement between the original molecules has changed, in the infrared radiation and other thermal radiation, plastic molecules rearrangement, so that the original area greatly reduced.
The contraction materials commonly used are PVC, POF, PE and so on. At present, POF shrinkable film: the most widely used, with its high surface gloss, good toughness, tear strength, heat shrinkable uniform and suitable for automatic high-speed packaging, especially the good advantages of environmental protection is recognized by the majority of manufacturers, can also be called environmental shrink film, so the use of a very wide range; PVC shrink film: chemical name: polyethylene, a toxic material, not environmental protection, low toughness, gradually replaced by POF, generally suitable for chemical non-environmental protection industry; PE shrinkable film: generally used in the beverage industry the most widely, characteristics: good flexibility, impact resistance, tear resistance, not easy to damage, not afraid of moisture, shrinkage rate, suitable for the product is relatively heavy shrinkable film packaging. Suitable for cans, glass bottles, beer, mineral water and other large quantities of automatic shrink packaging goods.