1. Outer Layer Materials:
The outer layer materials are typically chosen for their good mechanical strength, heat resistance, excellent printing performance, and optical properties. The most commonly used materials include polyester (PET), nylon (NY), oriented polypropylene (BOPP), paper, and other similar materials.
2. Intermediate Layer Materials:
Intermediate layer materials are utilized to enhance specific properties of the composite structure, such as barrier properties, light-shielding properties, fragrance retention, and strength. Commonly aluminum foil bag used materials for this purpose are aluminum foil (AL), aluminized film (VMCPP, VMPET), polyester (PET), nylon (NY), polyvinylidene chloride coated film (KBOPP, KPET, KONY), EVOH, and other similar materials.
3. Inner Layer Materials:
The primary role of the inner layer material is for sealing. Since the inner layer structure comes into direct contact with the inner contents, it must be non-toxic, odorless, water-resistant, and oil-resistant. Commonly used materials for the inner layer include cast polypropylene (CPP), ethylene-vinyl acetate copolymer (EVA), polyethylene (PE), and its modified materials.
