Plasma Cutting - WeldQuip

THE PROCESS

The plasma cutting technique is a method that relies on accurately controlled minimal heat to sever metal, rather than using mechanical means. The Plasma Machine creates an electric arc between the Plasma Tungsten electrode and the parent metal, effectively melting it to form a precise cool cut. Plasma cutters are designed to operate using compressed air, which means you'll need to have an air compressor to hook up to your machine. Alternatively, you can use bottled compressed Air or Nitrogen. The small hole in the cutting tip and the swirl ring narrows the flow of air in a centrifugal manner, generating a focused plasma stream that is applied to the workpiece. Since plasma is electrically conductive, the workpiece is required to be grounded. When the plasma arc makes contact with the metal, its intense pinpoint heat causes the metal to melt. Concurrently, the high velocity of compressed air/gas expels the molten material.

CHOOSING A CUT & TORCH

Type of cut

There are 2 types of cuts, a clean cut or a severance cut. Every plasma cutter is designed with specific limits regarding the thickness of metal it can effectively handle. These limits are defined by two key measurements: the maximum clean cut thickness, which represents the optimal thickness for achieving a high-quality cut, and the maximum severance thickness, which indicates the maximum thickness the cutter can penetrate if the priority is simply to cut through the material. Typically, the severance thickness exceeds the clean cut thickness, and it's important to note that these cutting capabilities can vary based on the type of metal being processed.

Torch

There are two primary types of arc ignition used in plasma cutting, The first type is High Frequency (HF) ignition, which requires the plasma torch to be positioned close to the workpiece for the arc to ignite and initiate the ionisation process. In this method, the arc jumps from the torch to the metal surface. The second type is On Air Ignition, which allows the torch to ignite automatically with a simple button press, thanks to a spring-loaded mechanism within the torch head. This method is particularly user-friendly, as it can effectively cut through rusty or poorly clean materials.