| Factor | PET | PE | CPP |
|---|---|---|---|
| Typical position | Outer layer | Inner sealant layer | Inner sealant layer |
| Main strength | Print stability, stiffness, clarity | Heat sealing and moisture resistance | Higher heat resistance and clarity than PE |
| Common role | Carries print and structure | Food-contact seal layer | Clear, heat-tolerant seal layer |
| Relative note | Used with functional inner layers | Best sealing performance | Slightly lower material price than PE |
PET provides the printable outer surface
PET holds print accurately, adds stiffness, and can remain transparent. It commonly sits outside the laminate where it protects graphics and gives the pouch a cleaner hand feel.
PE provides the sealing surface
PE is commonly used as the food-contact inner layer because it heat-seals well and resists moisture. Its sealing behavior makes it central to many pouch structures.
CPP handles more heat
CPP offers higher heat resistance and transparency than PE and can also serve as an inner layer. Its material price is slightly lower than PE, but selection should follow filling temperature and seal requirements rather than price alone.
Other layers solve other risks
PET, PE, and CPP do not cover every need. Aluminum foil or VMPET improves light, oxygen, and moisture barrier. Nylon adds puncture resistance and is often used in vacuum or retort structures. One example is an outer PET layer, a nylon middle layer, and an inner CPP layer.
The product decides the laminate
A clear dry-product pouch may need a different construction from an oily food pack or a vacuum bag. Match each layer to printing, barrier, puncture, heat, and sealing requirements.
Decision Guide / Recommendation
Choose PET as the outer layer when print stability and stiffness matter. Choose PE inside when seal reliability and moisture protection are priorities. Choose CPP inside when higher temperature tolerance and clarity are needed. Add nylon or a foil barrier only when the product requires their functions.
FAQ
Can PET be used as the sealing layer?
PET is normally selected as the outer printable layer. PE or CPP is more commonly used inside for heat sealing.
Which material has the best heat-seal performance?
PE provides the strongest general heat-seal performance among PET, PE, and CPP.
When should CPP replace PE?
CPP is useful when the inner layer needs higher heat resistance or greater clarity. The filling and sealing process should be checked before changing materials.
Do I need aluminum foil for every food pouch?
No. Foil or VMPET is chosen when strong light, oxygen, and moisture barrier is required.
Why is nylon added to a laminate?
Nylon increases puncture resistance and is useful in vacuum or heat-tolerant structures that need more mechanical strength.
Get a Packaging Recommendation
Send these details so our technical team can recommend a practical structure and prepare an accurate quotation.
- Product and fill weight
- Finished size, including relevant side seals or gussets
- Order quantity
- Material structure or performance needs
- Printing requirement and color count
- Destination country or port
If you have a physical sample, send it for material-structure analysis and closer matching.
Request a Packaging Recommendation