In simplicity, some kind of gas (often compressed air) is Ionized into plasma state with high temperature.
This plasma gas is blown out of the nozzle to the surface of the material to be cut and form an electric arc.
The plasma gas is at very high temperature and it melts the metal. Meantime, the melted metal is blown
away by the plasma flow, leaving a gap of cutting.
Frequently asked questions about plasma cutting machine
Q(1) What can be cut with plasma cutting machine ?
A: Plasma cut cut common metals, including mild steel, stainless steel, aluminum, copper, etc.
Q(2) What type of gas should be used with plasma cutting machine ?
A: Selection of the type of gas is very important when cutting different types of metal.
Often nitrogen is used to cut thick metal, oxygen to cut carbon steel, and argon-hydrogen is used to
cut stainless steel and aluminum.
Q(3) What are the types of starting the plasma arc ?
A: Two main categories: contact or non-contact. Contact refers to the process of nozzle has an initial contact
with the material to be cut (which is connected to one electrod) in order to start the plasma arc.
Non-contact type utilizes high voltage and sometimes also high frequency small pilot arc to start the plasma
Q(4) Can plasma cutting cross a separation of material ?
A: No. When the electric arc of plasma sees no metal at a gap, discontinuous of current will stop the arc.
Advanced plasma cutting machine often has the feature to re-initiate the arc.
Q(5) Does the plasma cutting yield taper ?
A: Yes. Most commonly the cutting edge will have some kind of taper. More advanced plasma cutting machine
yields less taper.