subject: The Working Mechanism Of Plasma Cutters [print this page] Plasma cutters may be described as plasma torches which are used to cut steel and other electrically conductive metals. Plasma cutters are available in a range of shapes and sizes. The smallest plasma cutter is a compact, hand-held unit while the largest may be the state-of-the-art CNC plasma cutters that include giant size cutters that use robotic arms. Regardless of the size or shape of plasma cutters, the working mechanism is the same as they are all constructed around roughly the same design.
Plasma cutting is a process that is used to cut steel and other metals of different thicknesses using a plasma torch. Engineers describe plasma as the fourth state of matter. Plasma is produced by passing inert gas around an electrical discharge. The gas is blown out at high speeds by means of the electrical arc and this gas is superheated to the plasma state.
In the earlier welding method, a barrier of inert gas was used around the plasma arc to protect the weld from oxidation. Latter day engineers working on this welding principle realized the possibility of boosting the temperature by accelerating the flow of gas and limiting the opening through which it passed.
With this innovative thinking, the engineers successfully developed a device which could generate enormous amount of heat which could be used to cut a metal. This enormous amount of power generated by this machine made it feasible for the engineers to cut through the hardest of metal with tremendous ease and speed and more importantly the cut is smooth and precise. Plasma cutting is indeed a fascinating and progressive technology.
Plasma cutters use different types of methods to start the arc. In some units, the arc is created by putting the torch in contact with the work piece. Some cutters use a high voltage, high frequency circuit to start the arc.
In plasma cutters, an electric arc or an electric discharge is sent through nitrogen or argon gas or oxygen which is made to pass through a small channel with a limited opening. At the core of this channel is a negatively charged electrode. When power is introduced to this electrode and its tip is brought in contact with the metal that has to be cut, a circuit is created which eventually creates a spark.
This spark heats the gas as it makes its way through the small channel, and this heating in turn converts the gas into a plasma state. A stream of plasma is created that cuts through the metal smoothly and easily while moving at an incredibly high speed.
CNC plasma cutters have revolutionized the art of welding as they use specialized software that controls and directs the plasma torch. CNC plasma cutters are known for speed, accuracy, efficiency as also repeatability for the plasma torch.
The distinct feature of plasma is it can reach temperatures as high as 30,000 Fahrenheit and can very easily cuts through up to two inches of metal. CNC plasma cutters are even more efficient because they are driven by computer numerically driven controlled software. The biggest advantage of plasma cutters is that they do not damage the surface of the metal that is being cut and as such problems like warping and paint damage are not there.
There are two types of plasma cutters - manual and automatic and each has its own set of merits and drawbacks. So based upon your need, choose the apt plasma cutting machine instead of overbuying with features you may never need or use.
