It’s not uncommon for our customers to package products that have a particularly strong odor such as car fresheners, incense, food, or even animal bait. Sometimes, it is desirable for the smell to permeate through the bag so that the consumer can sample it. In other cases, the odor must be kept securely inside the bag. The property commonly used to quantify how well a material contains an aroma is called its Oxygen Transfer Rate or OTR. OTR is the steady state rate at which oxygen gas permeates through a material at a specific temperature and humidity.
While oxygen is the gas used for testing purposes, the property relates to any type of gas. Simply, the lower the OTR, the better a material will contain the scent of the product inside. Most people aren’t aware that a standard polyethylene bag doesn’t do a very good job of containing aromas. You may have noticed this when storing particularly potent foods in zipper bags and then opening up the refrigerator. In fact, polyethylene is considered a permeable material that freely allows gases to move through it. If a better odor barrier is needed, R.V. Evans carries several Automated Packaging Systems materials that can be tested for suitability. As a general rule, as the barrier property increases, so does the cost.
Good: PTCL Polyester laminated to linear low density polyethylene – The polyester provides the barrier properties of this particular structure. Lamination film also offers ink protection and is perfect for retail applications due to its excellent stiffness and high gloss. This material is commonly used in standup pouches.
Better: NYLN LifeX™ Barrier Film – This is a co-extruded material that incorporates nylon to provide very good gas barrier properties. In addition to containing aromas, it is also suitable for use in modified atmosphere packaging and as a gas, flavor, and solvent barrier.
Best: CBAR High-Barrier Packaging Film – This product is also co-extruded and incorporates EVOH and nylon to provide superior barrier properties.
Because every application is different, we always encourage customers to test the compatibility of any material with their product and unique performance expectations to determine its fitness for use. Technical data information for all APS materials can be requested via this short request form here. These materials can be coupled with the usage of an automatic bagging machine and/or an automatic bag sealer.
As always, you can reach us at 800-252-5894 or at http://www.rvevans.com