The Amazing Cutting Power of Plasma

There are a lot of ways to cut through various materials and each method offers its own advantages and disadvantages.  Certain methods can only cut certain materials, certain methods are faster than others, and certain methods offer better accuracy or cut quality, and so on.  When it comes to metal fabrication, there is one method that is simply a cut above – plasma.  Plasma is often described as the fourth state of matter.  The three states of matter are ice, water and steam and the difference between these states relates to their energy levels.  For example, when we add energy in the form of heat to ice, the ice melts and then becomes water. To continue, when we add additional energy, the water then vaporizes into hydrogen and oxygen in the form of steam.  We refer to plasma as the fourth state because when you add additional energy to steam the gases become ionized.  The ionization process causes the gas to become electrically conductive and this electrically conductive ionized gas is called plasma.

For metal fabrication shops that cut electrically conductive metals, plasma cutting is ideal because the process utilizes electrically conductive gas to transfer energy from an electrical power source through a plasma cutting torch to the material being cut.  If you are unfamiliar with how plasma is able to cut through metal, the process is quite elegant and efficient.  A plasma cutting system consists of a power supply, an arc starting circuit and a torch.  These basic system components provide the electrical energy, ionization capability and process control that is necessary to produce high quality, highly productive cuts on a variety of different materials.  Our Machitech Automation systems use a constant current DC power source for the power supply.  The open circuit voltage is typically in the range of 240 to 400 VDC.  The speed and cut thickness capability is determined by the output current (amperage). The arc starting circuit is a high frequency generator circuit that produces an AC voltage of 5,000 to 10,000 volts at approximately 2 megahertz.  The plasma is produced when the voltage is used to create a high intensity arc inside the torch to ionize the gas.  The torch itself functions as the holder for the consumable nozzle and electrode, and it also provides cooling in the form of gas or water to these parts.  The plasma jet is achieved and maintained by the constriction of the nozzle and electrode.  Plasma is an ideal tool for metal fabrication because it is fast, efficient and provides pristine cuts on a wide variety of materials.