In the composite packaging, there are several kinds of raw material film: printing film, composite membrane, and film that can contact the product directly (such as food, medicine).
1. printing film: common printing film includes: PET (polyester film) common thickness of 12 microns, BOPP/Matt BOPP (BOPP film / extinction BOPP film thickness) are commonly used 18 micron, 25 micron and 28 micron, Nylon-BOPA (bidirectional La Nironbo film) common thickness of 15 microns.
2.: composite membrane composite membrane are common PE (polyethylene film thickness) at 25 microns -150 microns, CPP (cast polypropylene film) thickness can be adjusted freely, VMPET (aluminized polyester film) common thickness of 12 microns, VMCPP (VMCPP) can arbitrarily adjust the thickness of the aluminum foil (Aluminum, AL full) thickness is 7 microns, some printing film can also be used as intermediate in composite films, such as PET and Nylon-BOPA film.
3. films that can be in direct contact with the product (especially foods and pharmaceuticals), PE membranes, CPP membranes, and VMCPP membranes, can be placed directly into the innermost layer for contact with food. They are safe, but require that the material film must be of food grade.