Plasma cutting is a process in which an accelerated jet of hot plasma cuts through metal.
Plasma cutting generates an electrical channel of superheated, electrically ionized gas, or plasma. The gas, which can be shop air, nitrogen, argon, or oxygen, creates an electrical arc that conducts itself through a constricted opening on the torch head to cut the metal. The torch is mounted on a CNC table, or XY table. A CNC controller programs the torch to move in a specific profile or pattern to cut the part.
A plasma cutting system consists of the plasma arc power supply and torch, and the CNC controlled table. The torch is mounted onto the table and the CNC controller moves the torch around in x-y axes. Often the CNC can also control the torch in z-axis for full 5-axis cutting.
The type of gas depends on the metal being cut. For mild steel, stainless steel, aluminum, etc., the gas is usually oxygen (O2), nitrogen (N2), or other mixed-fuel gasses (hydrogen, argon, nitrogen, etc.).
While it’s impossible to measure, theoretical calculations have shown a temperature of above 40,000 degrees Fahrenheit, which is hotter than the sun. Anything in its path is disintegrated.
There is very little maintenance required with a plasma cutter.
Plasma parts should be replaced every 3-4 weeks.
The initial capital investments to purchase a high-definition plasma ranges from $100,000 – $400,000, depending on the size of the machine.
Operating costs consist of electricity, water, compressed air, gasses, and consumable parts. Plasma cutters cost approximately $5 – $6 per hour to run.
Plasma is ideal for cutting larger parts, typically ranging from 1 inch up to 20 – 30 feet, with accuracies ranging from +\- .15-.020.
By nature of the plasma technology, plasma is limited to cutting about 2 inches of mild steel. In stainless steel, the plasma can typically cut up to 1 ½ inches.
Ideal applications for plasma include cutting steel, brass and copper and other conductive metals for use by fabrication shops, automotive repair and restoration, industrial construction, and salvage and scrapping operations. Stainless steel and aluminum can be cut by plasma, though are not ideal due to the reflection of the torch and low melting point of the plasma cutter.
Yes. Through the AKS laser alignment tool, an operator can load the table with an existing part located through the laser alignment tool and cut additional feature into the part.
Yes. In plasma cutting, recent improvements with the Hypertherm XPR, using argon, offer excellent etching into mild steel, stainless steel or aluminum. Previously, nitrogen etching was available, but results were less accurate.