| The health and welfare of toolmakers that use | | | | Many shops use a centralized vacuum system |
| graphite to make electrodes for use the EDM | | | | designed for the removal of fine dust particles, such as |
| machining of molds should be a high priority for | | | | graphite. It is important to have enough air velocity in |
| management. In addition to the health issues for the | | | | the vacuum system to be effective. It is |
| workers, the very expensive machinery, such as the | | | | recommended to have an air velocity of 500 ft. per |
| EDM machines and milling machines, must be | | | | minute and the air in the lines should travel at a rate of |
| protected from the damaging effects of graphite dust. | | | | 2,000 ft. per minute in order to prevent the dust from |
| EDM and injection molding are inseparably linked in the | | | | settling inside the duct work. |
| manufacturing process of plastic products. | | | | With a centralized system it is much easier to |
| Anyone who has worked with graphite in the | | | | efficiently manage the dust from the various machine |
| manufacturing of EDM electrodes is keenly aware of | | | | tools because the system is more efficient and the |
| the need for proper dust removal during the machining | | | | hoses can be strategically placed. Special wheel |
| process. Many ill-equipped shops have very little | | | | guards are available for surface grinders that act as a |
| equipment to handle the dust generated during milling | | | | turbo to remove the dust into the vacuum system. |
| and grinding operations. | | | | Newer milling machines which are more or less |
| Safety | | | | dedicated to electrode machining are equipped with |
| The MSDS (material safety data sheet) for the | | | | extremely effective dust removal systems. The |
| synthetic graphite used in EDM show that there are no | | | | sealed chamber around the work area enables the |
| carcinogenic properties associated with graphite. It is a | | | | vacuum to capture a high percentage of the dust. This |
| chemically inert material and contains no volatile | | | | development has dramatically reduced the amount of |
| components. It is also used for medical purposes, such | | | | graphite dust in the shop environment. |
| as implants and heart valves in the human body. | | | | An additional method of dust removal is the use of a |
| This is not to say that graphite is totally harmless | | | | curtain of coolant surrounding the milling cutter. This |
| though. It can be very irritating to the skin, eyes, and | | | | prevents the dust from ever escaping and is very |
| nasal passages. It can cause stinging, redness and | | | | efficient. This feature is available on some milling |
| watering of the eyes, and itching of the skin. This can | | | | machines as well as an accessory that is easily |
| be a very annoying experience when a toolmaker is | | | | installed. |
| expected to produce a close-tolerance electrode with | | | | A Clean Shop Environment |
| a fine finish. | | | | Graphite dust is highly conductive and has been |
| Controlling the Dust | | | | responsible for the damage of many expensive tools |
| The simple but very ineffective solution is to wear | | | | and machines. Glass scales can give false |
| particle masks. Experience shows that this stop-gap | | | | measurements due to the settling of dust. Electronic |
| measure is a failure. The mask soon is clogged with | | | | equipment can be short-circuited by the dust as well. |
| the fine dust and the operator is left breathing a | | | | The grimy nature of graphite makes it especially |
| disgusting blend of bad-breath and graphite dust! | | | | annoying if it accumulates on work-benches and |
| Portable vacuums are the next best solution, but this | | | | desks. |
| also has many drawbacks. Often the filter in the | | | | It is in the best interest of everyone to make every |
| portable shop vacuum is not fine enough to trap the | | | | effort of maintain a clean and pleasant atmosphere in |
| microscopic sized particles, and they are simply blown | | | | a moldmaking or EDM shop. The toolmakers will be |
| back into the air. Also, because the vacuum hose is | | | | happier, the work will be better and the machinery will |
| often cumbersome to manipulate, operators fail to | | | | perform as it should. It is also very impressive to |
| properly align the hose to capture the most dust. | | | | visitors to see a clean, dust-free shop. |