Plasma Cutting 101
Understanding plasma cutting begins with defining plasma, gas that has become electrically conductive through the process of ionization. As an electrically conductive gas, plasma is utilized to transfer energy from the electrical power source through the plasma cutting torch to cut any electrically conductive material like mild steel, aluminum, brass or copper.
A plasma arc cutting system consists of three basic elements – a power supply, an arc starting circuit and a torch. These components provide the electrical energy, ionization capability and process control required to create efficient high quality cuts on a variety of metal materials.
A constant current DC power source is used as the power supply for plasma cutting. The output current of the power supply is what determines the speed and cut thickness capability of a plasma cutting system. The primary function of the power supply is to provide the necessary energy to maintain the plasma arc after ionization.
The arc starting circuit is a high frequency generator circuit that produces an AC voltage of 5,000 to 10,000 volts at approximately 2 megahertz. The voltage creates a high intensity arc inside the torch, which ionizes the gas and produces the plasma. The torch holds the consumable nozzle and electrode, and provides air- or water-cooling to these parts. The nozzle and electrode are constricted to maintain the plasma jet.
Plasma cutting is ideal for cutting steel and non-ferrous materials less than 2 inches thick. Benefits include ease of use, high precision cuts, high speed, and low operating costs (especially compared to water jet and laser). Plasma cutting is an effective means for cutting both thick and thin materials. Our plasma systems have a cutting capacity of up to 50mm/2” for mild steel and up to 150 mm/6” for special stainless steel applications. Since plasma cutters produce a very hot and focused cutting area, they are extremely useful for cutting metal in curved or angled shapes.