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Fiberglass plus coolant equals big mess

scojen

Stainless
Joined
May 21, 2004
Location
Zellwood, Fl.
I have a soon to be a recurring job in the shop cutting a fiberglass carbon composite that they want to run with coolant. We ran about 20 parts yesterday and needless to say it backed up the coolant system pretty good. We tried to use a filter cloth to strain the coolant through but it also backed up the system. While I would not normally run coolant while cutting fiberglass management has a definite fear of the carbon part of this being a health risk and maintained that using coolant to control the dust is the only acceptable method. What there not seeing is the mess the fiberglass/carbon particulate is doing to the coolant. So I guess I am looking for advice on how to separate the fiberglass swarf from the coolant to protect the machine and keep management happy, tongue in cheek statement there.
 
IME you are going to have a hell of a job filtering that out on the machine, so ;-

Can you run / divert the drain from the machine to a separate catch tank and pump fresh coolant on a ''total loss'' basis.

PS Correctly filtered the coolant should be reusable.

PPS A mist of coolant will keep the dust down.

PPPS Failing that, can you run a HEPAS (or something)filtered shop vac to keep the dust right down.
 
Lower the volume of coolant you are using to that required to keep the dust down and try to enlarge the area of the filter media. Let the swarf sit on the table and shovel it into a bucket periodically

the net effect ought to be less fiberglass in the sump.

I ran a lot of G10 parts for a lot of years on open knee mill CNC, and went back and forth on coolant.
 
Ok let me give you a bit more information the machine we are running this on is a Haas TM-2P. I am currently using a piece of breather cloth used in fiberglass layup to filter the coolant on its return to the coolant tank but this material clogs up pretty quick. I like the idea of using straight water as a coolant but will need to create a second system to be able to use it just for this job. Thinking of asking Haas about a price on another coolant system for this machine. Really do not want to do that but may have no other choice.
 
My philosophy is to never run fiberglass composites with a coolant, but set up as much dry-dust control as possible with good vacuum and dust collection around the source. I'm not an expert on carbon-fiber or other carbon composites, so I can't speak to the additional hazards of that material family, but where there is fiberglass, there will be highly accelerated machine wear. No matter what sort of slide and screw protection is built into the machine, some of the glass particulates will find their way into sliding ways and "other stuff".

If you are forced to run coolant, some of the above suggestions are about as good as it gets.
 
I have run several blanchard grinders, every single one has the large "bathtub"
coolant tank below. With enough capacity to allow settling (Hoeing out the tank
is an everyday chore)

Except one....

This was a "High proudction" model, and they had removed the tank underneath
(rather, they short circuited it to out back with a trough)
Out back was a add on unit with a "waterfall system" to get rid of heat
(I know, not needed in your case) and then a long series of baffles to
slow down the flow, to get rid of allot of the material.

I also have seen the cylindrical grinders (Vertical Campbell units) running
separate coolant processors like I posted, with the paper bed filtration units,
one example also had some cyclone pre-filtering units as well.

I am suggesting the opposite of others, use max. coolant flow, maybe even some additional nozzles running all the time (at various points on the table)
to "sluice out" the machine, keeping the material in suspension, and
keeping the machine clean.
 
I’m about to face similar problems cutting CFRP.

How big are your parts?

My parts are small, so I’ve created a fixture “tank” - basically an aluminum fixture plate with 2” high x 1/4” thick acrylic walls. I used acrylic so I could see through the sides - and also to be sacrificial in the event of a collision with a tool or tool holder. The CFRP sheet is clamped to the top of the plate and then submerged in water. The tank is filled about 1” over the part with water - can use a shopvac to suck out the contaminated water between cycles. If you’re using small tools (and moderate rapid speeds) the amount of water that gets sloshed out of the tank should be minimal.


Edit: Adding screenshot of “tank” in Solidworks. The base fixture plate is actually an Orange Vise 8x20 Vise Pallet...
Screenshot 2018-04-24 11.06.06.jpg
 
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We run a high temp composite here. We use as much coolant as possible for a couple of reasons
1: To keep the dust down, the composite we machine is about 60% glass fiber
2. Cooling, the material we machine has a extremely low heat transfer rate so the cutter ends up absorbing all the heat generated. Without coolant a cutter may survive for about 18" of cut. These are carbide cutters,they will turn blue and die very quickly without coolant.

We use a tank with weirs in it to let the stuff settle out, filter systems with this crap we machine, at least for us, were useless and a constant problem.
 
We build waste treatment systems and have to deal constantly with hair and fibers. Flushable wipes and diapers have cost the industry millions of dollars in damage to pumps. You can not use a a passive strainer or filter with fibrous materials, you have to actively clean the filter. The suggested deep bed paper roll filter will work really well. However it is a gravity system and you need another pump as well in most cases. I did a job on really fiber loaded waste a couple years ago using an Amiad T strainer with the manual Brushaway assembly and a blowdown valve. That might work just fine for you. We actually automated it with a drive motor and an actuated ball valve. It worked well enough that we currently use one we build that is 10" in diameter and 3 feet long with a brush motor. I'm designing a much larger one at the moment for 400 gpm continuous flow.
 
As one or two others have said, you might need a paper roll filter system with a float switch to advance the paper when it gets blocked, like this. We called them Philips paper filters at work, where they were used on a few of the older machines, but I think that was just one manufacturer.
 








 
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