•We like to call plastic flexible packaging composite packaging bags.

•Literally speaking, it means that film materials of different properties are bonded together and compounded to play the role of carrying, protecting and decorating products.

•Composite packaging bag means a layer of different materials combined together.

•The main layers of packaging bags are generally distinguished by the outer layer, middle layer, inner layer, and adhesive layer. They are combined into different rows according to different structures.

•Let YPAK explain these layers to you:

•1.The outermost layer, also called the printing layer and the base layer, requires materials with good printing performance and good optical properties, and of course good heat resistance and mechanical strength, such as BOPP (stretched polypropylene), BOPET, BOPA, MT, KOP, KPET, polyester (PET), nylon (NY), paper and other materials.

•2. The middle layer is also called the barrier layer. This layer is often used to strengthen a certain feature of the composite structure. It needs to have good barrier properties and good poly moisture-proof function. Currently, the more common ones on the market are aluminum foil (AL) and aluminum-plated film (VMCPP). , VMPET), polyester (PET), nylon (NY), polyvinylidene chloride coated film (KBOPP, KPET, KONY), EV, etc.

•3. The third layer is also the inner layer material, also called the heat sealing layer. The inner structure is generally in direct contact with the product, so the material requires adaptability, permeability resistance, good heat sealability, transparency, openability and other functions.

•If it is packaged food, it also needs to be non-toxic, tasteless, water-resistant, and oil-resistant. Commonly used materials include LDPE, LLDPE, MLLDPE, CPP, VMCPP, EVA (ethylene-vinyl acetate copolymer), EAA, E-MAA, EMA, EBA, Polyethylene (PE) and its modified materials, etc.