Plasma Cutting Principle: Plasma is often described as the fourth state of matter. We generally refer to three states: solid, liquid, and gas. The most common substance, H2O, exists in three states: ice, water, and steam.
The difference between these three states lies in the amount of energy they contain. If we add energy to ice, water is formed, i.e., liquid. If we add more energy, steam is formed. If we add enough energy to a gas, we find that its physical properties change dramatically. A highly ionized, hot gas composed of ions, electrons, and neutrons-plasma-is formed.
Many principles governing the flow of electric current through metals can also be applied to the plasma arc. For example, when the cross-section of the plasma arc is obstructed, its resistance and temperature increase, but the current remains constant. This high temperature and kinetic energy of the plasma arc are applied in plasma cutting. The working principle of a CNC plasma cutting machine is to use compressed air as the working gas and a high-temperature, high-speed plasma arc as the heat source. The metal to be cut is locally melted, and simultaneously, a high-speed airflow blows away the melted metal, forming a narrow kerf.
