It’s the same soft packaging bag, yet some foods remain crisp for three months while others become damp and spoiled within two weeks—the difference often lies in the barrier properties of the packaging. High barrier packaging materials are a core technology for extending the shelf life of food, but high barrier properties aren’t necessarily better when it comes to price. Choosing incorrectly can lead to unnecessary costs. This article explains the types, application scenarios, and selection logic of high barrier materials.
I. What does it block? Oxygen, moisture, and aroma
The main objects that packaging materials need to barrier against are three types: oxygen, moisture, and aroma (volatile substances). Oxygen can cause oil oxidation and rancidity, food browning, and microbial growth; moisture can lead to dampness in dry goods, clumping in powders, and softening of biscuits; aroma loss directly affects the flavor experience of food. Different foods have varying sensitivities to these three substances: nuts are most sensitive to oxygen, biscuits to moisture, and coffee and tea to aroma loss. Clearly identifying what needs to be barriered is the first step in selecting high barrier materials.
II. Overview of Mainstream High Barrier Materials
Aluminum foil (AL) is the most comprehensive barrier material, offering almost complete protection against oxygen, moisture, and light, making it commonly used for packaging high-end tea, pharmaceuticals, and sterilized food. However, it has high cost and poor flexibility, as it may develop pinholes after bending. EVOH (ethylene-vinyl alcohol copolymer) has oxygen barrier properties close to aluminum foil, but it is transparent and recyclable. Its barrier performance may decrease in high humidity conditions, so it is typically used between two layers of material. PVDC-coated film has good barrier properties and moderate cost, and was widely used in the past, but it has faced considerable environmental controversy. Aluminum-coated film (VMCPP/VMPET) is a cost-effective choice, offering better barrier properties than ordinary film but less than pure aluminum foil. For the difference between aluminum foil and aluminum-coated film, you can refer to our previous release.Comparison Article Between Aluminum Foil and Aluminum-Laminated Film。
III. Which Products Must Be Packaged in High Barrier Packaging
Food products requiring a long shelf life are the main users of high barrier packaging: nuts and fried snacks (where oil oxidation is the main threat), coffee and tea (for aroma retention), meat products and seafood (to prevent oxygen and microbial contamination), infant formula and nutritional products (to protect against oxygen and moisture), and pharmaceuticals and health supplements (which are sensitive to moisture and oxygen). In contrast, short shelf life, ready-to-consume products (such as breathable packaging for fresh produce), and products that do not require long-term storage can be adequately packaged with standard packaging, without the need to pay for unnecessary barrier properties.
Four. Cost and Structural Design of High Barrier Packaging
The cost of high barrier packaging is mainly determined by the material structure and the number of layers. Single-layer high barrier films (such as PVDC-coated films) are the most cost-effective and suitable for medium to short shelf life requirements; two-layer composites (such as PET/AL) are suitable for moderate shelf life; three or more layer composites (such as PET/AL/PA/PE) are used for products requiring high-temperature sterilization and ultra-long shelf life. Under the premise of meeting shelf life requirements, the structure should be simplified as much as possible to control costs. When purchasing, use shelf life testing to verify: package the product with the candidate packaging, test key performance indicators under accelerated aging conditions, and determine the structure based on data rather than experience.
V. Practical Suggestions for Purchasers
First, clearly define the shelf life target and transportation and storage conditions, which is the starting point for material selection. Second, request suppliers to provide barrier test data for similar products, comparing oxygen transmission rate (OTR) and water vapor transmission rate (WVTR). Third, obtain samples for actual testing, especially focusing on barrier performance in transportation scenarios such as folding and dropping. Fourth, pay attention to sealing and bagging processes; even if the barrier layer is excellent, poor sealing will render all previous efforts useless. High barrier packaging is a comprehensive engineering effort involving both structural design and process control. Choosing a factory with testing capabilities is more important than simply comparing material prices.
If you are planning a high barrier packaging solution, feel free to contact us. We can design the barrier structure based on your product characteristics and provide test data support.
In addition to high barrier packaging materials, we also offer composite packaging solutions using various materials such as PE, PP, PET, and aluminum foil. Please visit us.Om PackagingExplore a more comprehensive product line.