Machinery & Engineering

What you need to know about plasma cutting

Plasma cutting is the process of cutting through materials (usually metal) with the use of a jet of heated plasma.

The Basic Process

The basic process of plasma cutting involves coming up with a channel of plasma which will go through the material that will be cut. There will be completed the electrical circuit from the cutter to the grounding clamp. This is done by blowing compressed gas through a nozzle at a very high speed.

The electrical arc will be formed within the gas. The electricity going through the plasma is going to create enough heat that will melt through the material. The blowing action of the plasma will also eliminate the melted material, which will complete the process.

Plasma cutting, like the service offered by Metal 4 U, is a very efficient means of cutting thick materials. It can be used for cutting up steel with a thickness of up to 150 mm. Unlike other forms of cutting, the use of plasma is ideal for cutting curves and even angled shapes.

The formation of the arc follows a three-step process:

  1. High voltage arc ionizes the air which can be found in the torch head.
  2. A pilot arc forms within the torch head, which will then burn up the nozzle.
  3. A blast of air will then blow out the plasma from the nozzle towards the material to be cut. An electrical arc will then be formed outside of the nozzle going to the material and so the cutting process will not consume the nozzle.

The useful life of the nozzle is going to be limited by the number of arcs for which it will be used.

How Did It Start?

Plasma cutting is a process that grew out of plasma welding. This process was developed back in the1960s. It became popular right away because it offered several advantages over the traditional form of cutting, which used metal against metal.

Here are some of those advantages:

  • There are no metal chips produced during this process
  • It produces a more accurate cut
  • It produces a cleaner cut edge

Now, with the application of computer control on plasma cutting, it is even more accurate than before.

Safety During Plasma Cutting

So, is plasma cutting dangerous?

Like with the use of other machine tools, plasma cutting can be dangerous when proper safety precautions are not followed when performing the process. There is the risk of getting eye damage during the cutting. The injury is known as the arc eye. Face shields and other forms of eye protection will have to be used to prevent this kind of injury. Thick filters are needed when the arc of the cutter is visible.