[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[pct-l] Shiny Wine Box Bladders
At 06:33 AM 10/26/01, you wrote:
>The one shiny
>bag was left virtually unprotected under a ledge, but it wasn't even
>touched! Our theory is that a squirrel saw the mirror image of himself
>in the shiny bag and ran away.
The shiny "stuff" is a plastic/metal sandwich called Mylar
(....technically: Mylar is a plastic called polyethylene terephthalate and
comes with or without the metal, but most of us only notice the metalized
Regular plastic "breathes" (ie is gas permeable) so the squirrels could
smell the water inside.
Mylar does NOT breathe, so the squirrels couldn't smell the water, and left
See http://www.darylscience.com/VanillaBalloon.html for an experiment that
demonstrates this in a way even human noses can detect.
This lack of breathing is why Mylar helium balloons stay inflated, while
rubber helium balloons go flat quickly. The helium cannot get through the
Mylar. Helium (He) is one of the smallest molecules, so if it cannot get
through Mylar, larger stuff like Oxygen and Water don't have a chance.
This is the same reason that freeze dried food comes in Mylar pouches. With
the oxygen absorber packed inside (the thing with "do not eat" printed on
it) oxygen can't get in to ruin the food, and it stays good forever.....
for more information on Mylar.
Brick Robbins mailto:firstname.lastname@example.org