Why Use Barrier Packaging?
     There are two basic reasons for using barrier material for product packaging; one is to keep desirable elements in (such as flavor, aroma or a controlled atmosphere), and the other is to keep undesirable elements out (such as moisture, oxygen or other corrosive gases). Barrier Packaging is used to keep food fresh, prevent corrosion or rust, extend product shelf life and provide long term preservation.

What is MVTR?
     Moisture Vapor Transmission Rate (MVTR) is ameasurement of the amount of gaseous H²O that permeates through a material over a specific time and under specific conditions. It is also known as Water Vapor Transmission Rate (WVTR). These measurements are utilized to “compare” the amount of moisture barrier that one material provides vs. that of another. If you have a product that must be kept dry (such as medicinal powder or metal components susceptible to rusting) , then you would specify a package material with a low MVTR. The lower the MVTR value the “dryer” your product will be.

What Should Be Considered?
     With an innumerable amount of material choices now available; how is a product's package ensured to be constructed from the highest performing yet most economical material? At a minimum the following criteria should be considered; MVTR, puncture resistance, tear resistance, service temperature range, method of closure or sealing of the package and oxygen transmission rate. Understanding the criteria and the effects they have on your products is essential. A professional with a strong working knowledge of these criteria and the materials that exhibit them is indispensable in arriving at the optimally effective packaging method for a product.

Note: These are approximate values and should be used for comparison only. The specific content of the material, the filling process, sealing process, ambient temperature and humidity can all have effects on the actual MVTR levels.