Plasma cutting

Plasma cutting is a process that cuts through electrically conductive materials by means of an accelerated jet of hot plasma. Typical materials cut with a plasma torch include steel, stainless steel, aluminum, brass and copper, although other conductive metals may be cut as well. Plasma cutters work by sending an electric arc through a gas that is passing through a constricted opening. The gas can be shop air, nitrogen, argon, oxygen. etc. This elevates the temperature of the gas to the point that it enters a 4th state of matter.

How Does a Plasma Cutter Work?

The plasma cutting process is a thermal cutting method. Which means that is uses heat to melt the metal instead of mechanically cutting it.

The overall mechanics of the system is always the same. Plasma cutters use compressed air or other gases, such as nitrogen. Ionisation of these gases takes place to create plasma.

Typically, compressed gases come into contact with the electrode and are then ionized to create more pressure. As the pressure increases, a stream of plasma is forced into the cutting head.

The cutting tip restricts the flow to create a stream of plasma. It is then clamped onto the workpiece. Since plasma is electrically conductive, the workpiece is grounded via the cutting table.

When the plasma arc touches the metal, its high temperature melts it. At the same time, the high-velocity gases expel the molten metal.

Starting the cutting process

Not all systems work in the same way. First off, there's a generally low-budget version called High Frequency Contact. This is not available for CNC plasma cutters as the high frequency can interfere with modern equipment and cause problems.

This method uses a high voltage, high frequency spark. Sparking occurs when the plasma torch touches metal. This completes the circuit and creates the spark, which in turn creates plasma.

Another possibility is the Pilot Arc method. First, the spark is created inside the torch by a high-voltage, low-current circuit. The spark creates the pilot arc, which is a small amount of plasma.

The cutting arc is created when the pilot arc touches the workpiece. The operator can now start the cutting process.

A third option is to use a spring-loaded plasma torch head. Pressing the torch against the workpiece creates a short circuit that allows current to flow.

Releasing the pressure creates the pilot arc. The following is the same as the previous procedure. This brings the arc into contact with the workpiece.

Advantages and disadvantages

Advantages

Choosing a Cutting Method

Making your preference among one-of-a-kind slicing techniques comes right all the way down to the cloth, its thickness and alertness of the parts.

The encouraged slicing thickness for plasma slicing is among 15…50 mm.

The encouraged higher restrict of cloth thickness for a plasma slicing service is set 50 mm for carbon and stainless steel. Aluminium need to no cross beyond forty mm.

Everything above this is withinside the area of waterjet and flame slicing.

Laser slicing offerings need to be the favored choice for sheet metal and thinner plates due to its extra slicing high-satisfactory and speed. But laser slicing’s higher restrict is someplace round 25…30 mm.

Also, plasma slicing is faster and consequently inexpensive with plates beginning from round 15 mm. Then again, the query comes right all the way down to the specified high-satisfactory. It is, though, constantly viable to get a pleasant and clean end result with submit processing.