I had three ribs in a vac seal bag and decided to have a snack. I put the whole bag in the microwave for one minute. When the bell rang I looked inside and the bag looked like what you get at the fish store. The Quart bag was all blown up tight as a drum.
As the heat subsided the bag started to shrink back down. I know this is some kind of a chemistry thing but with the air all sucked out I did not expect the bag to blow up like that. I learn something new every day.