interesting wiki about plastics

xbb · 19 Apr 2011, 23:37

Not sure if you know it already, lot of infos there!
http://plastics.inwiki.org

runeazn · 19 Apr 2011, 23:49

thats pretty interesting,
imma going to take a free day and read it

TheSoulhunter · 30 Apr 2011, 13:55

Interesting...
Now I want UHMWPE keycaps!

Ultra high molecular weight polyethylene (UHMWPE), also known as high modulus polyethylene (HMPE) or high performance polyethylene (HPPE), is a thermoplastic. It has extremely long chains, with molecular weight numbering in the millions, usually between 3.1 and 5.67 million. The high molecular weight results a very good packing of the chains into the crystal structure. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. It is highly resistant to corrosive chemicals, with exception of oxidizing acids. It has extremely low moisture absorption, very low coefficient of friction, is self lubricating and is highly resistant to abrasion (10 times more resistant to abrasion than Carbon Steel). Its coefficient of friction is significantly lower than nylon and acetal, and is comparable to teflon, but UHMWPE has better abrasion resistance than teflon. It is odorless, tasteless, and nontoxic.

ripster · 30 Apr 2011, 15:53

I use that white stuff to build jigs for my table saw.

Slicker than Japanese curlers.

Findecanor · 30 Apr 2011, 16:29

Its coefficient of friction is significantly lower than nylon and acetal, and is comparable to teflon

Personally, I like more friction on the key caps. I just changed a board from Cherry POM to PBT key caps because the POM caps were too slick for me.
I think that this type of plastic might be very well suited for moving parts inside the key switches, though.

Swede · 02 May 2011, 20:52

Maybe HPPE is the plastic used in the sliders in cherry switches?
Can't check myself, only has alps and BS.
But it would be a real nice material to use for that purpouse, if it's not expensive as hell :/

ripster · 02 May 2011, 21:15

Anybody know what plastic is used to make Cherry MX switches?

I suspect PBT but haven't figured out a way to tell for sure and it's better for Cherry Corp to make it official anyway.

sixty · 02 May 2011, 21:41

Theres a PBT stamp in the grey case toggle switches. Dunno about the general ones.

ripster · 02 May 2011, 22:10

Thanks. No stamp in the general ones.

I'm gonna assume PBT.

Maybe I'll melt a few in the oven next time I'm making brownies.

itlnstln · 02 May 2011, 22:31

Cherry brownies? Hmm...

That's not what I put in my brownies.