[silverchair_13]

Hi, I have a problem with the graphite dusts around my machine, Makino S33. Dusts are all scattered around inside the cover. Suction seems not enough to grab those dusts. Any advice on creating a dust collection system? Funding wouldnt be a problem... Thanks!

[wrieken]

Hi,

Graphite Dust is very dangerous. You must fix that as soon as possible. Do not have children around that area. Graphite and Carbon Dust will give you CANCER and will never leave your body once it is in it.

I would never work in that kind of environment. Also, graphite dust is electrically conductive and once you get in on something it is nearly impossible to get it off. This is because at that small size static electricity holds it down to the material and being highly conductive it will contain that charge nearly forever.

This is why the U.S. military uses it as a weapon. Remember Bosnia? Graphite dust and strands took out nearly every electrical item including generators, telecommunications, etc.

I would say that you have a very serious problem.

We solved that problem by installing hoods with cleanroom level particle capture units and washing units.

For room size cutting and we did a lot of it. We had high powered tornado type vacs that where used for similar work at NASA, which also had very fine particle filters.

Also where filter masks. Our masks (designed for graphite type material) are those similar to gas masks but can filter out particles as small as the common cold virus.

There are many kinds of dusts in composite production, but in my mind nothing is more dangerous than carbon dust. It is biologically compatible with the human body. Meaning that the human body does not reject it like it does other dusts. All dusts are dangerous, but carbon dust is the king. That is why there is policy now in some countries to ban aircraft using carbon composites at airports that do not have HASMAT teams in place to handle carbon dust.

Hope this helps and Good Luck,

Will...

[Shandon]

Try a Royal filter mist with a five micron filter or an air vac system with a five micron or less filter. Graphite dust does not cause cancer!! The material is inert once it does inter the body it just stays there (it is not good for you but it does not cause cancer). Some other forms with carbon fiber might cause cancer but pure graphite does not. We manufacture heart valves and other graphite components specifically for the body. It is electrically conductive and that can pose problems with all kinds of electrical equipment.

[wrieken]

some links;

http://oem.bmj.com/cgi/content/abstract/59/7/473
http://www.ncbi.nlm.nih.gov/pubmed/2345988
http://www.springerlink.com/content/g74p2133up44mp3n/

Here is a good article to answer the initial question of "what to do"?
Title: Milling graphite without dust
http://findarticles.com/p/articles/m...67/ai_16339352

Hope this helps,

Will...

[Jim G]

I used to have the same problem. The stuff goes everywhere.

I built a filter box out of MDF for a 20x20 filter.
Using the finest electrostatic filter the dust was captured in the dirty side.
The shopvac white filter remains white.

Shopvac provides the suction, I made a box around the workpiece that the suction hose attaches to. Works great!

[paulC]

some links;

http://oem.bmj.com/cgi/content/abstract/59/7/473
http://www.ncbi.nlm.nih.gov/pubmed/2345988
http://www.springerlink.com/content/g74p2133up44mp3n/

Here is a good article to answer the initial question of "what to do"?
Title: Milling graphite without dust
http://findarticles.com/p/articles/m...67/ai_16339352

Hope this helps,

Will...

Those links do not say that graphite causes cancer, rather that there are other substances associated with the graphite industry that can. Graphite is a crystiline form of carbon. We are carbon based life forms.
Paul

[Jim G]

I certaily haven't experienced the "25%" of dust not being collected.

Mind you, I am machining relatively small electrodes with blanks in the 1" x 2 x 2 size.

[wongstein]

Graphite is a crystiline form of carbon. We are carbon based life forms.
Paul

Carbon nanotubes are known to be carcinogenic, and they're also crystalline forms of carbon.

It's true that the silica found in some graphite is much worse than pure carbon, but pure carbon dust is also known to cause fibrosis in the lungs over long periods of exposure, though probably less commonly.

This 2007 paper from the Mayo clinic suggests that the fibrosis leads to cancer.

"Myofibroblasts are normally induced transiently during wound healing, but inappropriate induction of myofibroblasts causes organ fibrosis, which greatly enhances the risk of subsequent cancer development."
http://www.ncbi.nlm.nih.gov/pubmed/17211838

Anthony

[silverchair_13]

Thanks for the replies.

The system I'm currently working on is limited only to suction/blowing. Liquid curtains or submerging the workpiece is quite impossible bec massive change on the current equipment will be required.

[devildog]

Dear Silverchair,

I believe you just need a bigger suction or dust collector machine. Higher horsepower. You need to have a higher suction rating. Make sure you get most the dust since those dust are very abrasive for your machine.(If I remember correctly.) If you are using slideways guides, it is good to put rubber protectors on top. If you are using linear guideways, you will probably have to replace them in the future.

[silverchair_13]

I made a blower and suction along with the table. Cutting depth is 1mm w/ 7k spindle speed (ideal scenario for roughing). There are still dusts (70%)escaping and reaching the splash guard.

If we produce fine dusts, around 95% is captured. But we did the "roughing scenario" to illustrate the worst case.

I put also some kind of air curtain around the spindle but to no avail...

The spindle seems to be creating a "turbulence" on the system and all my controls seemed aren't able to contain it...

Attached is the picture of my design. Please comment. Thanks.

[yanjue]

You can start by adding a booster in-line with your dust collector. (the booster or blower should be near of your machine)

Air blast can also help you

You also can add a capture hood near of your cutter with air blast to push dust into the hood.

We use a blower on our cnc router and the cnc is very clean.
And on on our cnc milling, we use small capture hood with little air blast. The machine is also very clean.

Yannick

[silverchair_13]

I have finalized my design already. It's doing great.

I added air nozzles and a transparent (curved to maximize air dynamics) cover around the spindle.

[xrdcarbon]

Dust, a common household word that can be defined as a finely powdered substance of various matters often suspended in the air. This is no different with the dust generated when machining EDM electrodes. Anyone that has machined graphite knows that the particles generated from the machining process are very fine and have a tendency to remain airborne. However, unlike common household dust, graphite dust has characteristics that must be taken into consideration.
here is "How to Deal with Graphite Dust" visit: http://buygraphiteforsales.blogspot....hite-dust.html.Source from XRD Graphite Manufacturing Co.,Ltd,top china graphite manufacturers company.that's all what i know,hope it helps