A coffee pouch is normally a laminated system. The kraft, matte, metallic, or glossy surface a customer sees is only the outside face; freshness protection and sealing depend on the complete construction.
Outer web: print and handling
PET or BOPP commonly carries reverse printing and the selected matte or gloss direction. It contributes dimensional stability, stiffness, surface durability, and a controlled presentation through converting, filling, shipping, and shelf handling.
Ink and adhesive: protected graphics and bond
Reverse printing places the ink between film layers. The adhesive combines the print carrier, barrier web, and sealant into one structure. Adhesive selection, application, and curing are therefore part of the production specification rather than a hidden commodity step.
Barrier core: selected to the performance target
VMPET provides a metallized barrier direction that balances protection, appearance, flexibility, and converting. Aluminum foil is selected when the approved project uses PET/AL/PE (100% Barrier) and opaque protection is the leading requirement. Coated and mono-material directions can be reviewed when their tested performance and recovery route suit the project.
Inner sealant: food contact and closure
PE or CPP provides the coffee-contact surface and heat-seal behavior. The correct sealant depends on pouch geometry, filling conditions, product contamination at the seal, equipment, zipper construction, and the final top seal.
The complete structure is what gets approved
Crystavo records the exact material order, thickness direction, printed side, adhesive system, barrier layer, sealant, valve, closure, dimensions, and applicable reports in the written specification.