What is a "barrier" and how is it measured?
Barriers protect what's inside your package. By limiting the exposure to oxygen, moisture, and light, barriers keep products fresh for longer periods. Products travel safe and are well-protected on store shelves with the help of barrier packaging. Stand up barrier pouches are especially popular for flavorful and aromatic food products.
Flexible plastic films also offer a wide range of barrier protection and offer many advantages over glass or metal. Plastics offer flexibility in design and shape, and they are lightweight and inexpensive. Many plastic films are heat sealable and are easy to print on.
The disadvantage of plastics is that they are permeable to light, moisture, and gasses. This is where the use of a barrier comes in.
What do we mean by "barrier"? A barrier is anything that blocks passage, and this includes what leaves or enters the package. A barrier functions to help products:
- Keep desirable flavors and aromas in.
- Keep undesirable moisture, oxygen, and gasses out.
- Prevent migration of moisture, oxygen, and gasses from within the film into the packaged goods.
How is a barrier measured? A barrier's performance is measured by the Oxygen Transmission Rate (OTR) and the Water Vapor Transmission Rate (WVTR). The lower the transmission rate, the better the barrier performance.
The ability level of a barrier is determined by the transmission of molecular gas (O2, CO2, N2), water vapor, and other organic solvents.