The plasma in Plasma Arc Cutting (PAC) refers to the physical state assumed by a gas after it has been exposed to, and reacted to an extremely high temperature. It becomes an ionized state of a plasma gas, also known as the fourth state of matter.
Plasma Arc Cutting is a process in which an electronic arc ionizes a gas, creating a super-heated highly focused plasma arc column that generates the heat for cutting ferrous and non-ferrous metal alloys. The super-heated cutting arc is focused through a constricting tip orifice which directs the arc to the work piece. Advantages are high cutting speeds, and a narrower heat affected arczone.
When used for cutting, the plasma gas flow is increased so that the deeply penetrating plasma jet cuts through the material and molten material is removed as cutting dross. PAC differs from oxy-fuel cutting in that the plasma process operates by using the arc to melt the metal whereas in the oxy-fuel process, the oxygen oxidizes the metal and the heat from the exothermic reaction melts the metal. Unlike oxy-fuel cutting, the PAC process can be applied to cutting metals which form refractory oxides such as stainless steel, cast iron, aluminum, and other non-ferrous alloys.
Check out Arc-Zone.com's Plasma Arc Cutting Guide: Setup Guide For PAC Torches