Oxygen absorbers, absorb the oxygen molecule, this does not necessarily create a vacuum seal. Air is about 20 percent oxygen and 80 percent nitrogen. Absorbers remove only the oxygen. The air left in the container is mostly nitrogen and will not affect the food or allow the growth of insects. Therefore, the final packaging may not have the appearance of being " vacuum-packed " because of the remaining nitrogen in the package. The only way to get a good vacuum seal inside the bag is to use a vacuum sealer. Let us know if you have further questions, happy to help!