Machining plastic 1

[MDowney]

Can anyone provide some guidelines for feeds and speeds for machining plastics? We have several vacuum formed parts that require secondary machining. We have experimented with a variety of tools as well as feeds and speeds with limited success and I need to get a better handle on the details. What are the best tools (ie. carbide, HSS, 2 or 4 flute, ect)? Thanks is advance for your replies.

Regards

Mark Downey
American Injection Molding

http://www.aimolding.com

 

[coachjoker]

It really depends on what type of plastic. But generally you should use a 2 flute endmill. Lots of coolant. Run your spindle as high as you can . Feed about .010" chip load.This should give you at least a 125RMS finish.
Good luck

 

[DANGERBOY]

The key to machining plastic in general is a sharp cutter w/ lots of chip clearance. There for I would suggest a HSS 2 flute end mill. You can get plastic to cut with carbide, but HSS is better!

 

[lmackie]

i am machining platic and the one person told you to use coolant. we dont here becuase of the mess and i find it doesnt work that good with coolant. but i think a 4 flute end mill works better then a 2 flute. use speeds and feeds similar to alluminum i found works really good for the platic we are using.

 

[MDowney]

Thanks for all the replies. They have been informative. I have actually come accross a VERY nice tool for cutting plastics. The tools are from CMT,

http://www.cmtusa.com/.

These tools are giving us a burr free finish. They have a steep helix and come in both up cut and down cut configurations. The down cut helix does a great job and it does not pull the parts up off of the fixture. I am very pleased with these tools. They are also two flute tools which I have found are recommended for cutting plastic because they take larger chips without melting the plastic. Again thanks for the feedback.

Regards

Mark Downey
American Injection Molding