On Friday, June 21, 2019 at 4:20:05 PM UTC-4, Joseph Gwinn wrote:
a

He has a job machining peek plastic. And has a problem with long
strings of the plastic jamming the chip conveyor. Now I am a novice
but do know enough when confronted with a problem the first thing to do
is find out what others have done. So how do you deal with strings of
pl
The key is to use SHARP HSS tools intended for plastic, and to keep the
plastic from melting and gumming everything up. Even plain water used as a
coolant will prevent melting, and will drain the static electric charge away.
To keep corrosion of the machine tool surfaces down, it is traditional to
dissolve some bicarbonate of soda in the water. Do not use any kind of fat or
oil, as it will degrade the plastic.stic?
stic?

As for chip breaking, the usual approach is to arrange for the chip to be
pulled away as fast as it is generated.

Joe Gwinn

The turning center is a Okuma LB15. Not the latest and greatest, but in good shape.

Using HSS makes sense. No need for carbide that can withstand high temperares and pressures. And HSS can be sharper.

I thougt it would be easy to find a comercial solution to plastic chips. but so far have not found one.

I think we are going to first try using air to suck the chip streams out of the machine. If that does not work well we might try CO2 cooling. I would think cooling would help with holding tolerances and finish, but not so much with actually getting the chip to break. Might be able to program pauses that would limit the length of the chips to 5 or 10 feet.

Will post our sucess or failure.

Dan