Some special products have different requirements for packaging materials,such as liquid product needs different barrier properties than a dry product,and similarly an acidic product needs different chemical resistance than a basic product
There are different plastic layers used in retort pouches as follows:
polyester (PET) – provides a gloss and rigid layer, may be printed inside
nylon (bi-oriented polyamide) – provides puncture resistance
aluminum (Al) – provides a very thin but effective gas barrier
food-grade cast polypropylene (CPP) – used as the sealing layer
polyethylene (PE) – can be used instead of PP as a sealing and bonding layer
This multi-layer structure prevents the retort pouch from being recycled into other retort pouches or food packaging. However, the material can be recycled into an aluminized resin or up-cycled into textile materials. The weight of a pouch is less than regular cans or bottles, and the energy required to produce each pouch is less than competing packaging from metals, paper, and glass.
