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KiddZimaHater
07-20-2012, 11:13 PM
How do you cut Polyethylene (White UHMW) with a bandsaw?
It would seem simple enough, but I ran into a big SNAFU.
The piece was 4-1/2" Diameter, and I was using my little 4x6 bandsaw with the only blade I have, (14 tooth).
Well, It took forever to even get 1/2" deep, then suddenly it pinched the blade, and all hell broke loose! :mad:
I tried again, and it kept pinching the blade! Damn it!!
I ended up putting it in my bench vise and sawing it by hand with a coarse-tooth tree saw!:p
What's the poop?

duckman
07-20-2012, 11:36 PM
To many teeth not enough set , next time try a chain saw.

BobL
07-20-2012, 11:51 PM
It sounds like the gullets are just packing with sawrf and then then its just trying to melt your way through, the slower it goes the gummier it gets and eventually it will pinch the blade. If you don't have a blade with fewer TPI Make a piece of angle out of two boards and cut it on top of that, i.e. cutting the wood after the PE drags the PE out of the gullets.

A_Pmech
07-20-2012, 11:56 PM
You need a MUCH coarser band. 2-3 TPI would be about right and about the coarsest you can get in 1/2" wide blade stock.

Rich Carlstedt
07-20-2012, 11:57 PM
I cut Polyethylene (aka PE) and Corian without a problem
Because of the low melting point (300 F) it wants to ball up and load your blade.
When PE drags across other PE, there is tremendous drag/resistance to movement and a great deal
of heat is created, making matters worse. Plastic "extruders" rely on this feature to further melt PE during
production processes.

To reduce the effect, you can freeze the raw material..somewhat, or blow lots of air on the cut to cool it, or slow down the blade
speed to reduce heat.

The method I use and it works wonderfully , even on Corian ( and no Carbide needed !) is
to rework the SET of the teeth on one blade (8-10 Pitch) to about .060 "
With a .025 thick blade. it gives great clearance and no heat.

If you notice the cut bending (like a "C") it means not enough clearance.
I used a hand saw set unit that Foley made.
Took about an hour, but saved lots of time

Here are two photos of some Corian being cut for my Monitor Engine Base.
A tough cut, but the pattern shows free cutting. Note the blade in the photo

Rich
http://i273.photobucket.com/albums/jj220/StationarySteam/P3140005.jpg
http://i273.photobucket.com/albums/jj220/StationarySteam/P3140010.jpg

vpt
07-21-2012, 11:08 AM
When I was cutting a big block of the stuff I had the same problem of the saw stopping but around half way threw the block. I found that holding a chunk of wood against the side of the blade to clear the teeth helped allot! Also pushing down and putting more pressure on the saw helped.

lane
07-22-2012, 12:05 AM
Get a course pitch blade like you might use for wood . 6 teeth are less per inch. and it will cut beautiful.