Cutting polyethelyene

[jimt]

I'm bidding a job to cut 1" thick polyethelyene sheets. any info on bits, cutting speeds/feeds would be ver helpful.

[uniguard@pamlico.net]

Hi Jim,

I’m relatively new at this cnc thing but over the past couple of months I have cut a considerable amount of 9/16” HDPE. I have had good luck with carbide, up-spiral end mills at .65. The big trick was getting the material stay on the table at the end of the cut. It took awhile, but I found that the tabbing feature works great for this situation. Hope this helps.

Ken

[donchandler]

Jim,
Polyethylene cuts great, no problem with melting, etc. I have cut up to 4" thick with no problem. If you can spiral down through it it, you can run at 1"/s. I have used all kind of bits with good luck. For the 4" thick, I used a 1/2" end mill. Only thing I could find long enough, worked great.

[djhazeleger@mindspring.com]

I have been working a lot with the tiff conversion, cutting pictures using a v bit. I was wanting to use an opaque plastic material, put a black backing on it to achive a greyscale look. the deeper the cut, the darker it gets. Since I've had real good luck with cutting hdpe I bought a piece to give it a try. Much to my dismay, making such fine cuts the shavings either welded back together or never completely cut forming a mat like carpet. I did play with it a little more with a 1/4 in bit. I achieved the greyscaling I wanted by varying the depth of cut. Does anyone have any advise? Is their a different plastic this may work on?

[mtills]

Don,

Where do you buy 4" thick polyethylene?

Matt