Heating PE in oven.

From: 	daniel_hess-at-VNET.IBM.COM[SMTP:daniel_hess-at-VNET.IBM.COM]
Sent: 	Saturday, December 06, 1997 8:58 AM
To: 	tesla-at-pupman-dot-com
Subject: 	Heating PE in oven.


Am in the process of collecting material to assemble a stacked PE capacitor.
I'm really dissappointed by the quality of 6 mil poly that is otherwise
amply available in size, price and so on. Biggest problem is that all the
poly I've inspected, they all seems to have a sandpaper-like grit sub-
stance imbedded, (sometimes puncturing,) the poly sheet, which I consider

I finally located, at Home Depot, a higher quality 6 mil poly sheet called
Pergo, which is marketed as a floor underlayment. This stuff costs
about four times the going rate of conventional drop-cloth poly but the
stuff appears to be free of all the usuall contaminates and defects.
The Pergo has a green tint which from all the tests I've run thus far,
will perform as a dielectric at least as well as regular 6 mil poly.
I was concerned that the green color might "do" something to the poly.

But, like most rolled-up poly this stuff has a few wrinkles and creases,
albeit less than the cheaper poly I've looked at. I discovered that if
I place the cut up pieces flat on a cookie sheet, bake in my oven at
200 F. for 15 minutes or so, the creases in the poly relax and the stuff
flattens out nicely.

My question is; Does heating the poly in this manner degrade or harm
the poly in any way that might decrease its effectiveness as a dielectric?

I'm even wondering if it might be beneficial to bake the entire stack for
a few hours, (-at- 200 F.) as a way to "seat" the thing. My thinking is that
besides eliminating air and any other foreign material from the assembly,
ensuring the best possible contact among its componets will also
increase efficiency.

Anybody out there have experience with heating PE?

Regards, Daniel Hess