Dry pet food requires a grease-resistant package, holding product in quantities up to 25 pounds, keeping it clean, and providing a surface for multicolored advertising. Packaging bags are most popular consisting of lacquered paper lined with PP or PE either laminated or as a separate layer, for heat sealing, abrasion resistance and a grease barrier.
Some semi-moist pet food products, with less than 35% moisture content, are flexibly packaged in bags providing moisture, oxygen and aroma barriers. Several multilayer structures are used:
- Paper/tie layer/metallized OPP/ionomer
It is important to use ionomer resins to pave the way for sealing via grease and fat. Tie layers are either acid copolymers or LDPE. The necessary barrier traits were provided by metallized OPP.