PET heat shrinkable film is a new type of heat shrinkable packaging material. Because it is easy to recover, non-toxic, tasteless, good mechanical properties, especially in line with environmental protection and other characteristics, in developed countries, polyester (PET) has become a substitute for PVC (PVC) heat shrink film ideal alternative.
However, the ordinary polyester is a crystalline polymer, ordinary PET film through a special process can only get 30% of the following thermal shrinkage. To obtain a higher heat shrinkage of the polyester film, it must be modified. That is, in order to prepare a polyester film having a high heat shrinkage rate, it is necessary to perform copolymerization of a conventional polyester, i.e., polyethylene terephthalate. The PET film after copolymerization has a maximum heat shrinkage of up to 70%.