LDPE protective film (low density polyethylene film)
LDPE protective films are generally produced by two processes of blow molding and casting. The thickness of the cast polyethylene film is uniform, but it is the most widely used because of its high price and low cost. LDPE protective film is a translucent, shiny, soft texture film with excellent chemical stability, heat sealability, water resistance and moisture resistance, freeze resistance and boilable. Its main disadvantage is its poor barrier to oxygen. It is commonly used in the inner film of composite flexible packaging materials. It is also the most widely used and widely used plastic packaging film, accounting for more than 40% of the consumption of plastic packaging film. .
Since the polyethylene molecule does not contain a polar group and has high crystallinity and low surface free energy, the printing performance of the LDPE protective film is poor, and the adhesion to the ink and the adhesive is poor, so before printing and compounding Surface treatment is required.
PET protective film (polyester film)
The PET protective film is a film material made of polyethylene terephthalate as a raw material, formed into a thick sheet by extrusion, and then biaxially stretched. It is a colorless, transparent and lustrous film with excellent mechanical properties, high rigidity, hardness and toughness, puncture resistance, friction resistance, high temperature and low temperature resistance, chemical resistance, oil resistance, air tightness and aroma retention. Good, it is one of the commonly used barrier composite film substrates. However, PET protective film is relatively expensive, generally 12 μm thick, and is commonly used as an outer layer material for retort packaging, and has good printability.
Aluminum protective film
The most widely used aluminum protective films are mainly polyester aluminized film (vmpet) and cpp aluminized film (vmcpp). The aluminum protective film has both the characteristics of a plastic film and the characteristics of a metal. The surface of the film is coated with aluminum to prevent light and ultraviolet radiation, which not only prolongs the shelf life of the content, but also improves the brightness of the film. It replaces the aluminum foil to a certain extent, and has the advantages of low cost, good appearance and good barrier property. Aluminum protective film is widely used in composite packaging.
Take A Look At The Three Most Widely Used Protective Films
Post time: 2019-01-03