What is the easiest plastic to machine?

[pced]

The answer is PET. Many of you may know of it as Ertalyte. Ertalyte was the first PET offered on the market extruded by Quadrant EPP out of Reading PA. Several other extruders are now in the game making PET more affordable. PET is now a little more expensive than Delrin. PET meets or exceeds all of Delrin's mechanical and chemical properties but the big difference is dimensional stability during machining. You can literally take a 1.0" thick 12x12 PET plate, machine .750" off of 1 side and it will stay flat. Try that with Delrin and it will turn into a Pringle potato chip! PET is great for structural, bearing and wear or FDA or USDA parts with complex features and deep cut outs. PET is extremely stable and it holds tolerance.

For more information on PET go to: http://www.cncplastics.com/PDFs/PET.pdf or call 1-800-265-7351.

For general information on plastics please visit us at: http://www.cncplastics.com/

[mugim0e]

I beg to differ. You are making more of a statement than answering a question. I wouldnt say its the easiest to machine. PTFE is easy to machine because its so soft and you can take large cuts . I think you are confusing whats the best plastic to use in terms of an application for a component, rather than the general machining of it.

[pced]

I guess I should have been more clear. Many plastics have high internal stress levels. PET is the most dimensionally stable plastic material to machine, especially when trying to maintain tight tolerance or flatness. Teflon is very easy to "cut" because it's so soft, but you have to admit it is like trying to hang onto a bar of soap. 30 A Durometer Polyurethane is also soft but virtually unmachinable without freezing it first and keeping it frozen through all of your procedures. Plus, Teflon, whether it be extruded or compression molded, does not have nearly the dimensional stability of PET nor the rigidity, and with Teflon's extremely high coefficient of thermal expansion, it gets difficult to hold tight tolerances with even moderate application related temperature swings.

I can appreciate your opinion but I think that most would agree, when machining tight tolerance parts out of plastic, Teflon would not be their first choice.

[pced]

Yes, I do have free samples of pretty much any plastic you can think of with the exception of the really expensive stuff. Of course my posts are really an advertisements, but I'm trying to present them in the form of public service to members. Is the other forum where I should be posting my propaganda?

If so, my bad.
-Paul

[pced]

I appreciate the information. I'm new to the site. Was there a specific sample you wanted? If so, e-mail me your adress and I'll be happy to send you what you are looking for. pced@msn.com

[mugim0e]

I wasnt refering to teflon as a first choice, i used it as an example of a material that is easy to machine.Teflon is terrible for stability, and dimensional accuracy.

[chan luci]

Hi pced,
Availability of PET in stock shape is still a BIG question in India, atleast. If you give me a hand in marketing this in India, which holds hell a lot of potential for stock shape machining, I am with you. write back to me at custompartsonline@gmail.com

[planar39]

well im not familiar with pet or such, have used delrin, polycarbonate, phenolic, uhmw, g4, abs, too many to remember,

now in my shop we use Nylon, its hard and resisiant, and with carb inserts, 1100+ sfm, and .015-.020 chip per tooth easy, just need to rough it out, if i dont move fast enough it wants to melt. Also its very bad for coolant, coolant eats it and makes sludge, so i recommend an air blow off.

this probably didnt help,

PS; secret tip, to weld polycarb slabs together, use ether as a glue

[dvcgraphics]

hello, i use foamalux.. very cool..

see here

[dvcgraphics]

see here ;-)

[dvcgraphics]

i use foamalux, see here

[dvcgraphics]

Originally Posted by pced The answer is PET. Many of you may know of it as Ertalyte. Ertalyte was the first PET offered on the market extruded by Quadrant EPP out of Reading PA. Several other extruders are now in the game making PET more affordable. PET is now a little more expensive than Delrin. PET meets or exceeds all of Delrin's mechanical and chemical properties but the big difference is dimensional stability during machining. You can literally take a 1.0" thick 12x12 PET plate, machine .750" off of 1 side and it will stay flat. Try that with Delrin and it will turn into a Pringle potato chip! PET is great for structural, bearing and wear or FDA or USDA parts with complex features and deep cut outs. PET is extremely stable and it holds tolerance. For more information on PET go to: http://www.cncplastics.com/PDFs/PET.pdf or call 1-800-265-7351. For general information on plastics please visit us at: http://www.cncplastics.com/

i use foamalux