Not all Bags are Created Equal (Quick Lesson on OTR)

Vacuum packaging is a method of packaging that removes air from the package prior to sealing the package.  Many food industries (meat, cheese, seafood) use vacuum packaging in order to extend the shelf life of these products.

Once air has been eliminated from the package, there must be an adequate oxygen barrier and seal integrity to keep a low oxygen concentration inside the bag. Otherwise, the driving force created by the oxygen partial pressure differences (21% outside the bag and 0-2% inside the bag) will cause oxygen to re-enter the bag.

OTR (Oxygen Transfer Rates) is the amount of oxygen that passes through a defined area of film over 24 hours.  This is where the importance of your bag comes in.  See our chart below of various OTR rates for films.  The lower the OTR, the better the barrier.

OTR Chart_Logo

If you are vacuum sealing a bag with a high OTR, this defeats the purpose of vacuum sealing since the bag will easily allow oxygen right back in the bag.  In order to properly vacuum seal your bag, you must choose a bag with a low OTR.


7 responses to “Not all Bags are Created Equal (Quick Lesson on OTR)

  1. How low does the OTR need to be to seal it for a week?

    • Hi Andrew,
      Our standard vacuum bags have an OTR of 4 and that would be recommended for vacuum sealing your items. We would not have any data on OTR for a week since most of our customers are wanting to vacuum seal for the long term

  2. How was the OTR of your bags tested? Was the transfer rate tested with 100% oxygen on one side of the film, and 0% oxygen on the other? Or with air (21% oxygen) on one side, and 0% oxygen on the other?

  3. We need to vac seal some small electronic devices, for shipping. We need a static safe bag, not necessarily the conductive bags, just non-static generating. I need a bag 12 or 14 inches square. Is there a specific bag or material you would recommend?

  4. I have been told by another vac seal equipment and bag supplier that nylon is required in a bag, or it will not be considered vacuum-able. I have never heard this before. Can you comment on the need for nylon as a bag material? Are there any static-safe bags that contain nylon?

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