Plasma Cutter

What is Plasma? 

In simple terms, plasma is the fourth state of matter. Matter is commonly referred to as having three states – solid, liquid and gas.

Matter is altered from one state to another by introducing energy such as heat. As an example, water will change from a solid (ice) to its liquid form when a certain level of heat is applied. Should even more heat be applied, it will change again from a liquid to a gas (steam).

Now, if the heat levels are increased again, the gases that make up the steam will become ionized and electrically conductive, becoming plasma. A plasma cutter will use this electrically conductive gas to transfer energy from a power supply to any conductive material, resulting in a cleaner, faster cutting process than with oxyfuel. 

How does a Plasma Cutter Work?

At a basic level, plasma cutting is a process that uses a high-velocity jet of ionized gas that is delivered from a constricting nozzle orifice. The high velocity ionized gas - the plasma - conducts electricity from the torch of the plasma cutter to the workpiece. The plasma heats the workpiece, melting the material.

The high-velocity stream of ionized gas mechanically blows the molten metal away, severing the material.

Plasma Cutting System Components

    • Power supply -- The plasma power supply converts single or three-phase AC line voltage into a smooth, constant DC voltage ranging from 200 to 400VDC. This DC voltage is responsible for maintaining the plasma arc throughout the cut.  It also regulates the current output required based on the material type and thickness being processed.

    • Arc Starting Console – The ASC circuit produces an AC voltage of approximately 5,000 VAC at 2 MHz which produces the spark inside of the plasma torch to create the plasma arc.

    • Plasma torch – The function of the plasma torch is to provide proper alignment and cooling of the consumables.  The main consumable parts required for plasma arc generation are the electrode, swirl ring, and nozzle.  An additional shielding cap may be used to further improve cut quality, and all the parts are held together by inner and outer retaining caps.

Do I need an Air Compressor to use a Plasma Cutter?

While different gasses can be used for plasma cutting, most people today use compressed air for the plasma gas. In most shops, compressed air is readily available, and thus plasma does not require fuel and compressed oxygen for operation.

Gasweld stocks a wide range of Air Compressors which are suitable for use with Plasma Cutters. Click Here for the entire range of Air Compressors

Air Compressors

What can a Plasma Cutter be used for?

Plasma cutting can be performed on any type of conductive metal - mild steel, aluminium and stainless are some examples. With mild steel, operators will experience faster, thicker cuts than with alloys.

Plasma cutting is ideal for cutting steel, and non-ferrous material less than 1 inch thick. Plasma cutting really shines in some niche applications, such as cutting expanded metal, something that is nearly impossible with oxyfuel. And, compared to mechanical means of cutting, plasma cutting is typically much faster, and can easily make non-linear cuts.

Benefits of Plasma Cutting

A plasma cutter is a fantastic cutting solution for a number of applications and provides an alternative to traditional cutting methods such as mechanical saws.

The benefits of plasma cutting include ease of use, higher quality cuts and faster travel speeds.

Whether it’s repair and maintenance work or projects which require large cutting volumes, Plasma Cutting is certainly a method to consider.  

Plasma Cutting

Plasma Cutting v Oxy-Fuel Cutting

Oxy-fuel cuts by burning - or oxidizing - the metal it is severing. It is therefore limited to steel and other ferrous metals which support the oxidizing process.

Metals like aluminium and stainless-steel form an oxide that inhibits further oxidization, making conventional oxyfuel cutting impossible. Plasma cutting, however, does not rely on oxidation to work, and thus it can cut aluminium, stainless and any other conductive material.

Plasma cutting machines are typically more expensive than oxyacetylene, and also, oxyacetylene does not require access to electrical power or compressed air which may make it a more convenient method for some users. Oxyfuel can cut thicker sections (>1 inch) of steel more quickly than plasma.

Click Here for Gasweld's Range of Plasma Cutters and Accessories