Plasma Cutters

Industrialization and the allied processes have traversed the good and bad times in equal stride. The demands made on the various industries via the special markets for the products and services have increased with the advent of the cutting edge technological approach possible today. One such cutting edge technology is the plasma-arc process. The plasma cutters have their origin dating back to almost half a century ago. This unfolded during the zenith of the Second World War, in the pursuit of improving the technology applied to the welding and joining of aircraft material. The effort resulted in a method of welding that was developed and used a protective shield of inert gas. This shield functioned around an electric arc developed and protected the weld from oxidation or the reaction of oxygen in the atmosphere on the weld.

The technology applying the plasma cutters was taken to the next level during the next couple of decades. The observation was that on restricting the opening, through which the inert gas was channelized, the heat that was produced by the process was also increased to a great extent and this was very desirable in the procedure. Similarly, it was also observed that the resultant reduced opening caused the gas flow to speed up and blow out via a channel that optimized the entire effort. The plasma cutters found a great commercial market and use in good time. However, the extremely expensive process further opened up avenues for experiments that involved large burning services and systems to amortize the equipment at hand.

There were a number of dedicated experiments carried out that have culminated in the application of the plasma cutters of today. A number of manufacturers realized the enormous benefit involved in the ability to burn ferrous and non-ferrous metals. Today, the demands of the smaller components within the industry are catered to by a number of manufacturers who offer portable plasma cutters. The plasma cutters available today are so light that they can be carried around with least effort. Some of the plasma cutters are generated from units that have built-in air compressors, making the operation completely mobile. Most of these light weight and portable plasma cutters are primarily suited for cutting sheet-metal and extended light work.

There are plasma cutters that operate as 220 volt machines powered with 50 to 80 amp output current. These cutters can be mounted on a truck and taken to the job site. These plasma cutters also work by emitting an electric arc through the gas passing through the constricted opening, which could be nitrogen, argon, oxygen or any other gas. The cutters increase the temperature of the gas within to a point where it takes on the quality of the fourth state of matter, the first three being solid, liquid and gas. This fourth state is also referred to as the additional state or plasma. The metal sheet being cut is not only a part of the resultant circuit, but it also facilitates the electrical conductivity of the plasma to cause the arc generated to be transferred to the work intended.

The restricted opening, through which the gas passes, causes it to be thrown out at great speed, to cut through the molten metal. The gas also covers the perimeter of the cutting area and thus shields the work area. In many of the latest plasma cutters used today, there is a pilot arc generated between the electrode and nozzle, which is used to ionize the gas and create the plasma state even prior to the transfer of the arc. There are plasma cutters that also apply a method that involves touching the torch tip to the metal sheet to generate a spark. This method uses a high-frequency starting circuit and functions just like a spark plug. There are plasma cutters that also apply an electrode at the center, with the nozzle just below, to generate a swirl ring.