Plasma cutting is a kind of arc cutting and is characterized by the formation of a highly concentrated plasma arc, glowing between the electrode and the material which melts and throws it from the cutting area. Plasma arc is a highly ionized gas, moving from plasma nozzle near the speed of sound.
The temperature of the plasma beam oscillates with values of 10 000 – 30 000 K and depends on current intensity and the composition of plasma gas. Due to high heat of the plasma arc cutting can be realized in a wide speed range. However, it determines the quality of this process and as a speed grows quality falling down, decreasing the width of the cutting gap and finally takes no intersection. Depending on the type of cutting material we use different plasma gases. ZAKMET uses air, nitrogen, and mixtures thereof. Current source is a plasma aggregate. During the cutting torch is kept in an upright position or at a right angle (during gounging or beveling) to a separate object surface and at a constant distance from it. Torches, in which a plasma gas is air, are equipped with special electrodes, which are resistant to oxidation. They are used hafnium electrodes placed in a copper corpus, providing intense heat dissipation.
This type of cut allows the separation of all electrically conductive materials. Plasma cutting process is carried out in a manual, mechanized and robotized. Along with the oxygen cutting dominates the industry – about 90% cutting machines sold on the world market are plasma or oxygen cutting machines.
Advantages of plasma cutting machines are high cutting speed and undistorted elements. Thanks to the high temperature plasma arc cutting begins immediately, without heating. However, disadvantages of this process are high noise level, a large number of gases and fumes and the risk of electric shock.