Common Barrier Packaging Polymers—Their Functions & Applications
- Published: June 07, 2016, By Tom Bezigian
Plastics for use in barrier packaging is commonplace today. The list below of common barrier polymers provides their functions and applications in tabular form for easy reference by the reader.
Hundreds of thousands of tons of polymers are used globally each year for various packaging uses. A small percentage of these are barrier polymers, which of course are used to prevent the migration of “something” into the package. That something is usually oxygen, water, and light. Sometimes the purpose is to keep something in, such as in modified atmosphere packaging, and sometimes it is to let something out, such as carbon dioxide in cheese packaging.
Below is a table of common polymers used in multilayer food packaging. It should come in handy for R&D personnel and perhaps even marketing and sales people when presenting a list of capabilities to customers.
Suggestions for follow-up articles are welcomed. If none are received shortly, the next blog will review a list of common adhesives used for lamination in packaging.
| Plastic Polymer | Functions in Multilayers | Applications |
| Polyethylene (PE) |
Heat-sealable food contact layer Moisture barrier Can be combined with gas/aroma barriers (e.g., PA, EVOH) |
Breathable packaging for fresh produce (LDPE), HDPE) Carton liners (LLDPE) |
| Polypropylene (PP) |
Moisture barrier To provide mechanical strength Can be coated with heat seal coatings (PVDC, acrylate) Can be combined with gas/aroma barriers (e.g., PVDC coatings, PA, EVOH) |
Modified atmosphere packaging thermoformed containers for microwavable packaging, hot-filled packaging |
| Polyamide (PA) |
Gas/aroma barrier To provide mechanical strength Heat resistance Can be used as outside layer of a heat seal film → film will not stick to the sealing bar surface |
Boil-in-bag packaging Thermoformed packaging |
| Polyethylene Terephthalate (PET) |
Gas/aroma barrier Moisture barrier To provide mechanical strength Heat resistance |
Plastic bottles for carbonated soft drinks Meat and cheese packaging Snack food wrapper Boil-in-bag Sterilizable pouches Ovenware containers |
| Polystyrene (PS) |
Gas permeability Printability Can be combined with gas/aroma barriers (coextruded or laminated) → commercially available structures: e.g., PS/PVDC/PS, PS/PVDC/PE, PS/EVOH/PE, PS/EVOH/PP |
Breathable packaging for fresh produce (e.g., fresh meat packaging) printable outside layers |
| Ethylene Vinyl Alcohol (EVOH) |
Oxygen barrier Needs to be protected from moisture → often sandwiched (coextruded) between PE or PP, in some applications also sandwiched between PET, PA, or PS |
Modified atmosphere packaging Packing of oxygen-sensitive food |
| Polyvinylidene Chloride (PVDC) |
Gas/aroma and/or moisture barrier To protect the surface from scratches and abrasion Heat-sealable food contact layer Often copolymers of vinylidene-chloride and ester-type monomers (e.g., ethyl acrylate) |
Modified atmosphere packaging applied as coating or coextruded film |
| Ethylene Vinyl Acetate (EVA) |
Moisture barrier Adhesion layer (tie layer) for coextrusion of polar (e,g., PA, PET-G) and non-polar (e.g., PE) or BOPP films |
Modified atmosphere packaging applied as coating or coextruded film |
| Polycarbonate (PC) |
Heat resistance Mechanical strength Moisture barrier |
Microwavable packaging, hot-filled packaging Modified atmosphere packaging barriers for fruit juice cartons |
| Polyvinylchloride (PVC) |
Gas/aroma barrier Mechanical strength |
Fresh food packaging (e.g., PVC/PE films) Modified atmosphere packaging (e.g., PVC, EVOH, PE films) |
| Polyethylene Naphthalate (PEN) |
Gas/aroma and moisture barrier heat resistance |
For hot refills, rewashing, reuse beverage bottles (e.g., beer) |
| Glycol modified polyethylene terephthalate (PET-G) |
Heat-sealable food contact layer |
Unit dose pharmaceutical Blister packaging |
| Ethylene Acrylic Acid (EAA) |
Extrusion coating tie layer between aluminum foil and other polymers Heat-sealable food contact layer Grease resistance Chemical resistance |
Food packaging applied as tie layer or heat seal layer |
| Ionomer |
Extrusion coating tie layer between aluminum foil and other polymers Heat-sealable food contact layer Heat seal through fat and contaminants Superior grease resistance Superior chemical resistance |
Food packaging applied as tie layer or heat seal layer |
Remember, your timely suggestions for follow-up articles are welcomed by writing me at This email address is being protected from spambots. You need JavaScript enabled to view it..
