What does “high barrier” mean in food packaging?
High-barrier flexible packaging is designed to slow the movement of substances such as oxygen and water vapour through the package wall. Depending on the food, light protection may also be important. The purpose is to help maintain product quality during the intended storage and distribution period.
“High barrier” is not one universal material grade or a guarantee of a specific shelf life. It describes a performance requirement that must be defined for the food, package format, storage conditions and target market.
Why are oxygen and moisture important to food?
Oxygen can affect fats, flavour and colour
Oxygen exposure can contribute to oxidation in products containing fats and oils, including nuts, seeds, chips and some snack foods. Oxidation may affect flavour, aroma and colour. Oxygen can also influence other quality changes depending on the food formulation.
Moisture can change texture and stability
Water vapour entering or leaving a package can affect crispness, softness, clumping and other product characteristics. Crispy snacks may lose crunch if moisture enters, while some products may dry out if moisture escapes. The correct moisture barrier depends on the product’s moisture sensitivity and target water activity.
Light can accelerate certain quality changes
Some products are sensitive to light exposure. Opaque, printed or metallized structures may help reduce light transmission, but the required level depends on the food and the overall packaging design.
What are common high-barrier packaging materials?
Flexible packaging structures often combine several layers, with each layer contributing different properties. Options may include:
- Metallized PET (VMPET): a polymer film with a thin deposited metal layer. It can provide barrier and appearance benefits in suitable laminate designs.
- Aluminium foil: can provide very high barrier to gases, moisture and light when the finished laminate and seals remain intact. Foil structures need careful consideration of flexing and handling.
- EVOH-containing films: EVOH can provide strong oxygen barrier under suitable conditions, often protected by other polymer layers. Its performance is affected by humidity and the specific co-extruded structure.
- Polyethylene (PE) sealant layers: commonly provide heat-seal functionality and moisture resistance, but PE alone is not generally selected as a high oxygen-barrier layer.
- PET outer layers: often contribute stiffness, print surface and mechanical performance; barrier performance depends on the full construction.
How do you compare barrier performance?
Two common measurements are oxygen transmission rate (OTR) and water vapour transmission rate (WVTR). OTR describes the rate at which oxygen passes through a material under stated test conditions. WVTR describes the rate at which water vapour passes through it. Lower values generally indicate lower transmission under the same test method and conditions.
When reviewing test data, check the units, temperature, relative humidity, test method, specimen thickness and whether the result applies to a single film or the complete laminate. A material datasheet value does not automatically represent the performance of a finished pouch with seals, folds, zippers or other features.
High barrier is more than the film structure
Even a high-barrier laminate can fail to protect a product if the package has weak seals, pinholes, flex cracks, poor converting quality or unsuitable closures. The whole pack must be considered, including:
- sealant selection and sealing window;
- seal width, cleanliness and consistency;
- puncture and flex-crack resistance;
- zipper, spout, valve or other functional components;
- pouch geometry, headspace and filling method;
- transport, storage temperature and humidity.
How should a food brand specify a high-barrier pouch?
Start with the food rather than choosing a material name first. Tell your packaging supplier what the product is, whether it is oily, dry, crispy or moisture-sensitive, the intended shelf life, storage conditions, pack size, filling method and whether nitrogen flushing or vacuum packaging is used.
Then agree on measurable performance targets, such as OTR and WVTR, and confirm the final structure through technical review and suitable package testing. Shelf-life validation should use the actual product in the final package under relevant storage conditions.
Does high-barrier packaging automatically extend shelf life?
No. A suitable barrier can help reduce one or more pathways of quality deterioration, but shelf life also depends on the food formulation, processing, initial product quality, hygiene, residual oxygen, seals, storage temperature, distribution and consumer handling. Claims about shelf life should be supported by product-specific validation.
Related packaging solutions
Explore custom stand-up pouches and printed rollstock film. Fuhehu Packaging can review laminate options and pouch specifications based on your food product and packing line.