Sealing Film Material Structure

Sealing films typically consist of three or more composite layers with different functionalities. For example, the aluminum foil sealing composite material described in patent literature includes a biaxially oriented polyester film (PET) substrate layer (7-25μm), an aluminum foil (AL) barrier layer (7-50μm), and a polyethylene (PE) heat-seal layer (40-60μm). These layers are bonded together with an adhesive to create a PET/AL/PE structure. The barrier layer effectively blocks oxygen and water vapor permeation, while the heat-seal layer ensures a secure bond with the container opening. Some products, such as electromagnetic induction sealing films, incorporate an elastomer or cardboard layer to enhance anti-counterfeiting and tear resistance.