RS at work fired this volley in news:94d50a8b-
:

I don't think you have thought this out. When you start, the air
pressure on the inside of the bad is the same as it is on the outside
of the bag.

In either scenario.

The bag is held shut by a less than hermetic seal, so as the air
pressure in the chamber drops, the air pressure inside the bag drops
also, but unlike the kid stepping on the ketchup packet, there is no
pressure on the other stuff in the bag.

You're not using a bell jar, you're using a plastic bag. OF COURSE there
is direct pressure (of 14.7psi) on every square inch of food in contact
with the bag. Where do you suspect that force would come from in your
"pressure packed" example, except from a differential between the inside
and outside pressures?


Think of what would happen to a cup of ketchup in a bell jar, as the
air pressure drops, any bubbles in the ketchup would come to the
surface and pop but the ketchup would just sit in the cup, assuming of
course that you didn’t hold the vacuum so long as to vaporize all of
the water.

F'criminy's sake... it's not a bell jar. It's a soft plastic bag! It
conforms to the surface shape of whatever is in it. It applies PRESSURE
to that surface, just as if someone had stepped on it.
..... snipped a bunch of non-sequitor stuff...

Another cool thing you can do with a chamber sealer is to back fill
the chamber with nitrogen or another inert gas. This is what they do
with potato chips to get an oxygen free packaging.

I'll let you continue to believe that until you see how a continuous
fill/seal line actually works.

In the case of potato chips and nitrogen fill, it has nothing to do with
differential pressures. The "chamber", when it exists at all, is a room,
with no pressure hardware, and no need for it.

LLoyd