Retort pouches and ready-meal packaging
Retort is the one application where the packaging must survive the preservation process itself: sterilisation under pressure, at temperatures that destroy ordinary laminates.
The preservation challenge
A retort pouch is filled, sealed, and then cooked — sterilised inside the pack under heat and pressure. Every layer, every adhesive and every seal must hold through this cycle, and then give long shelf life at ambient temperature afterwards. That requires near-absolute oxygen and moisture barriers. Delamination, seal creep or barrier loss are not acceptable.
How we engineer for it
The proven architecture is PET for strength and print, aluminium foil for the absolute barrier, and cast polypropylene as the seal — because CPP holds hermetic seal integrity at sterilisation temperatures where PE fails. Retort-grade adhesives and verified bond strength complete the system.
| Design parameter | Specification |
|---|---|
| Typical structure | PET/ALU/CPP (retort-grade) |
| Oxygen target | OTR < 5 cc/m²/day |
| Moisture target | WVTR < 2 g/m²/day |
| Typical grammage | 120–160 GSM |
| Seal layer | CPP — high-temperature |