Three layer film, is a 3-layered plastic film. This type of film has excellent barrier properties. It protects the packaged material from oxygen, moisture and sunlight and gives a long shelf life to products. It is specially useful in the case of food products that will have a shelf life of over 3 months.
The top layer is usually the printed layer, and the middle layer is a barrier layer of film with good barrier properties. The third layer is also a barrier layer which acts as the sealing layer also. There are several kinds of 3 layer films depending on the end use. In some cases Aluminium Foil is used in the middle layer to give extra barrier protection. In some cases, Nylon film is also used to retain the nice smell of aromatic products, and yet make the products visible to customers.