doc -
many yrs ago I had cause to investigate the 'failures' - what we found was with age the sealing efficient decreased.
goop build up, elements not running as hot, jaw warping / uneven sealing.
looks okay to the naked eye, but the seal is not as 'tight' as a brand new unit - especially at the corners/ends of the bag. basically, it starts "leaking" the instant it comes out of the sealer - albeit rather slowly....
certainly something poking a hole while moving about the freezer isn't going to help <g>
our experiments were constructed with frozen bags inside a freezer flooded with special gases. we could measure how much and how fast the outside gases got in....
I explained it like gluing two pcs of wood together. you can gloop up the seam, press the two pcs together to get good glue smear around, walk away; you will get a "bond"
if the two pcs are _clamped_ together, you get a better bond . . . |