When it comes to industrial tools, there is a powerful one which can cut through kinds of materials – plasma cutter. What is plasma? What is a plasma cutter? How does a plasma cutter work? Why is it so powerful?
To understand the way a plasma cutter works, we must know some definition about plasma. . This article also shows you the best way to know how a plasma cutter works.
Table of Contents
What Is Plasma?
On Earth, plasma is knowns as the fourth state of matter, after solid, liquid, and gas. Matter changes from state to state when it gets enough amount of energy like heat. An ice cube (solid) becomes water (liquid) when you heat it, the water becomes steam (gas) when you keep boiling it. So what happens when you keep heating the gas?
The gas being heated to a certain extent will become strongly ionized and electrically conductive and then, there comes plasma.
How Does a Plasma Cutter Work?
What Is a Plasma Cutter?
A plasma cutter is a machine that uses an accelerated jet of hot plasma to cut through electrically conductive materials. The materials here include steel, stainless steel, copper, aluminum, and other conductive metals. People often use the plasma cutter in industrial sectors such as automobile repairing, marine salvage, and mechanical work site.
How Does a Plasma Cutter Work?
The object of a plasma cutter is to cut through conductive materials, but how can this machine do its job? It creates an accelerated jet of extremely hot plasma which can go through the workpiece to make a cut. So, what does this jet come from?
The jet of hot plasma comes from the compressed gas. The gas including air, oxygen, inert, and others is created from a small high-speed forced nozzle of a torch pointing to the workpiece.
At this time, an electrical arc is generated from the external power supply and immediately ionizes the gas. Then, the plasma jet is created. This accelerated jet of plasma supplies a high level of heat to melt down the material. Meanwhile, compressed gas and high-speed plasma blow the melted metal away to cut things.
There are hand-held torches and computer-controlled torches for plasma cutter. Both are useful and effective.
Handheld and precision operation
For handheld tool, it operates quite simply. When you turn off the machine, nothing happens because there is no contact between the electrode and the nozzle in the torch. The connection of the electrode to the nozzle consumable parts in OFF mode inside the torch is safe. When you pull the trigger of the machine, a DC current from the power supply will flow through both electrode and nozzle. The plasma gas also comes in this stage.
When the compressed gas creates enough pressure for the connection between the electrode and the nozzle, it will force them to be apart. Immediately, there comes an electrical spark inside to impact and change the gas into a jet of hot plasma. The DC current now will flow from the electrode to the workpiece instead of the nozzle.
Inside the precision plasma touch, things are different. The electrode and the nozzle are separated by a wire wrapping around the electrode. This wire can create a vortex shedding from the plasma gas. When you start the power supply, there comes an open circuit voltage with up to 400VDC. The gas is now pressed to the torch. A swirl wire separated the nozzle and electrode helps create a swirling vortex from the plasma gas. The open circuit voltage can reach up to 400VDC when starting the power supply.
Now, the connection of the nozzle to the positive potential of the power supply will make the electrode at a negative. Now, the electrode becomes negative, while the nozzle is at positive as it is connected with the power supply. When there is an electrical spark from the arc starting console, it establishes a current path from the electrode to the nozzle and also creates a pilot arc of plasma.
When the pilot arc touches the workpiece, the current path changes to flow from the electrode to the workpiece instead of the nozzle. The following part will explain why the plasma jet has the shape like what you often see.
To cut the amperage selected at the beginning, the power supply ramps up the DC current. It also gets the new plasma gas instead of pre-flow one to use with the workpiece. At the same time, a shield gas comes from the shield cap to impact and re-shape the plasma arc. Now, you will have a super precise and quick cut.
Now, you can find answer to question: How does a plasma cutter work? The description above is the best way to understand the operation of a plasma cutter whether you are a mechanic or not.
This machine is so powerful that it can cut through many kinds of electrically conductive materials. It is especially useful when you want to make a complicated, curved, or angled cut. It can also work well on thick material. The plasma cutter is simply perfect.
Want to know more aspects of the plasma cutter? Please comment below what you need and share your questions.