Graphite and its effects on the human body and tool room equipment
The health and well-being of toolmakers who use graphite to make electrodes for EDM mold machining must be a high management priority. In addition to health concerns for workers, very expensive machinery such as EDM machines and milling machines must be protected from the damaging effects of graphite dust. EDM and injection molding are inseparably linked in the manufacturing process of plastic products.
Anyone who has worked with graphite in EDM electrode manufacturing is well aware of the need for proper dust removal during the machining process. Many poorly equipped shops have very little equipment to handle the dust generated during grinding and grinding operations.
Safety
The MSDS (material safety data sheet) for synthetic graphite used in EDM shows that there are no carcinogenic properties associated with graphite. It is a chemically inert material and does not contain volatile components. It is also used for medical purposes, such as implants and heart valves in the human body.
However, this does not mean that graphite is completely harmless. It can be very irritating to the skin, eyes, and nasal passages. May cause stinging, redness, and watering of the eyes and itchy skin. This can be a very upsetting experience when a toolmaker is expected to produce a close tolerance electrode with a fine finish.
controlling the dust
The simple but very ineffective solution is to use particle masks. Experience shows that this stopgap measure is a failure. The mask soon becomes clogged with fine dust and the operator is left breathing in a disgusting mixture of bad breath and graphite dust!
Portable vacuum cleaners are the next best solution, but this too has many drawbacks. Often the filter in a portable shop vac is not fine enough to trap microscopically sized particles, and they are simply blown into the air. Also, because the vacuum hose is often cumbersome to handle, operators don’t properly align the hose to capture most of the dust.
Many shops use a centralized vacuum system designed for the removal of fine dust particles, such as graphite. It is important to have enough air velocity in the vacuum system for it to be effective. It is recommended to have an air speed of 500 feet. per minute and the air in the lines must travel at a speed of 2000 feet. per minute to prevent dust from settling inside the ducts.
With a centralized system it is much easier to efficiently manage the dust from the various machine tools because the system is more efficient and the hoses can be placed strategically. Special wheel guards are available for surface grinders that act like a turbo to remove dust in the vacuum system.
Newer milling machines, more or less dedicated to electrode machining, are equipped with extremely effective dust removal systems. The sealed chamber around the work area allows the vacuum to capture a high percentage of the dust. This development has dramatically reduced the amount of graphite dust in the shop environment.
An additional method of dust removal is the use of a coolant curtain that surrounds the bur. This prevents dust from escaping and is very efficient. This feature is available on some routers, as well as an accessory that is easily installed.
A clean workshop environment
Graphite powder is highly conductive and has been responsible for the damage of many expensive tools and machines. Glass scales can give false measurements due to accumulation of dust. Dust can also short circuit electronic equipment. The dirty nature of graphite makes it especially annoying if it builds up on workbenches and desks.
It is in everyone’s best interest to do everything possible to maintain a clean and pleasant environment in a mold making or EDM shop. The toolmakers will be happy, the work will be better, and the machinery will work as it should. It is also very impressive for visitors to see a clean and dust-free store.
