I have to build a thermos and I can't use commercial stuff, just around the home sort of stuff. Please tell me what would make a good insulator and why besides styrofoam and fibre glass. and stuff like that. Oh and why is newspaper a good insulator.
2007-04-01 09:06:07 · 4 answers · asked by meh 4 in Science & Mathematics ➔ Engineering
All substances have a resistance to heat transfer including air film( the layer of air that is next to the object)
the more air pockets the more layers of air film and the resistance or R-value goes up.
Anything with air pockets is a good insulator- ex foam,cork,paper
if you take Fibreglass and squeeze it together it becomes compact and the air pockets are removed. Then it becomes a poor insulator just like a pane of glass.
If the air pockets are too large then the air will carry the heat through convection. so many tiny air pockets is best.
2007-04-01 09:26:41 · answer #1 · answered by frozenbrew 4 · 0⤊ 0⤋
The newspaper doesn't conduct heat well. One of the best I have run into is vacuum . I worked for NASA and we had special amplifier that used super conductor for the magnets to tune it. It was like everything was in this large double bottle and part of the procedure was to reduce the air in the inner bottle. Then we would pull a super vacuum between the two bottles and then we could start to cool it with liquid helium. After it was cooled down we could start the super magnets. Try vaccium I think u will like it.
2007-04-01 09:35:02 · answer #2 · answered by JOHNNIE B 7 · 0⤊ 0⤋
use lard(aka fat) it is available at most all grocery stores and is relatively cheap.vegetable lard exists but meat lard is the best. oh yeah try to seal it off with possibly a ziplock bag cuz once it leaks your drink or food will taste like ****
2007-04-01 10:56:24 · answer #3 · answered by g_wiz@sbcglobal.net 1 · 0⤊ 1⤋
things that air will not penetrate.
2007-04-01 09:14:56 · answer #4 · answered by Dotr 5 · 0⤊ 0⤋