Plasma cutting is a process that is used to cut steel and other metals of different thicknesses (or sometimes other materials) using a plasma torch. In this process, an inert gas (in some units, compressed air) is blown at high speed out of a nozzle; at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma. The plasma is sufficiently hot to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut.
The HF type plasma cutting machine uses a high-frequency, high-voltage spark to ionize the air through the torch head and initiate an arc. These do not require the torch to be in contact with the job material when starting, and so are suitable for applications involving computer numerical controlled (CNC) cutting. More basic machines require tip contact (scratch) with the parent metal to start and then gap separation can occur similar to DC type TIG welders. These more basic type cutters are more susceptible to contact tip and shield damage on starting.
The Pilot Arc type uses a two cycle approach to producing plasma, avoiding the need for initial contact. First, a high-voltage, low current circuit is used to initialize a very small high-intensity spark within the torch body, thereby generating a small pocket of plasma gas. This is referred to as the pilot arc. The pilot arc has a return electrical path built into the torch head. The pilot arc will maintain itself until it is brought into proximity of the workpiece where it ignites the main plasma cutting arc. Plasma arcs are extremely hot and are in the range of 25 000 °C.
Plasma is an effective means of cutting thin and thick materials alike. Hand-held torches can usually cut up to 50 mm thick steel plate, and stronger computer-controlled torches can cut steel up to 150 mm thick. Since plasma cutters produce a very hot and very localized "cone" to cut with, they are extremely useful for cutting sheet metal in curved or angled shapes.
In the past decade plasma torch manufacturers have engineered new models with a smaller nozzle and a thinner plasma arc. This allows near-laser precision on plasma cut edges. Several manufacturers have combined precision CNC control with these torches to allow fabricators to produce parts that require little or no finishing.
Robot plasma cutting is a process which uses high-velocity ionized gas, known as plasma, to heat and melt metals. The plasma then mechanically blows the molten material away to severe the work piece.
Plasma cutting is used to cut steel or a non-ferrous material less than one inch thick. Using a robotic plasma cutting machine offers higher quality cuts at faster travel speeds. This versatile application effectively cuts very thin & thick metals consistently.
In the last few years, these machines have drastically reduced in price and size, allowing more companies to utilize plasma cutting robotics. Many models are available, including the FANUC 120iB and the Motoman HP20-6.
Plasma cutting creates great angled or curved shapes, as well as a smoother surface than a manual application.
Plasma cutting robot automation will not only lower your costs, but will also introduce precise, high-quality cuts to enhance your products.