A plasma cutter is used in fabrication works to cut electrically conductive sheets of metals. These include steel, stainless steel, aluminum, brass, and copper, or any other metal capable of conducting electricity.
In this process, a jet of ionized gas that melts and severs a metal is released and heated to a high temperature of 20, 000 Celsius. Once hot, an electric arc forms between an electrode and the workpiece metal.
A welder then positions the electrode directly in the gas nozzle. Here, there’s a cooling process, with water being the main coolant. Additionally, cool air is useful in constricting the arc and forming a narrow, high-speed temperature stream of plasma.
In our review today, we’ll answer the question, how does a plasma cutter work? We’ll also dig in the preparation and various components of a plasma cutter.
Plasma cutting, getting ready
There is a checklist of the questions you need to answer in choosing the best plasma system. First off, you need to estimate the thickness of the metal. Different metals sizes require certain amperages.
You also need to have a clue of the quality you need since high amperage may give you more flexibility in terms of the output.
What metal will you cut? Nonferrous metals are hard to cut since they need more power. It’s essential to read the specifications of the metals you’re about to cut. You also must consider the power input. Smaller systems can run on 110/220 voltage.
How does a plasma cutter cut?
Just to recap, plasma cutter works by sending an electric arc through a gas that passes through a constricted opening or nozzle.
Does the gas matter? Yes. The gas may be air, nitrogen, argon, or oxygen. Each can be used alone or in combination, where you have thick sheets of metal.
With a speed of lightning, the gas cuts through the molten metal. Quite interesting. Indeed, the plasma jet can reach 40,000 F to pierce through a workpiece swiftly.
The plasma cutting process in details
You can find the plasma cutter and MIG welding machine combo in the market. But a welding machine is not a plasma cutter. Whereas a plasma cutter has unique features that ensure a smooth cutting process, the plasma cutting system falls into three categories.
- Conventional Plasma Cutting System
The conventional systems generally employ shop air to serve as the plasma gas. These devices typically come with a small nozzle and work almost similarly, as I have mentioned above. Nevertheless, with them, you cannot really manipulate the gas flow, which can make your work with thicker metals a little bit challenging.
However, they are quite easy to use and work efficiently in low-temperature places. Due to this reason, they are still in use in several working places.
- Precision Plasma Cutting Systems
Unlike the traditional ones, precision plasma cutting systems can generate a high amount of power and heat. The copper nozzles of these models are even smaller than their conventional counterparts, which boosts their efficiency by a mile.
Furthermore, they generally do come with a complex design, which helps them to withstand the heat for a prolonged period. Moreover, they are also compatible with several types of gases, such as oxygen, nitrogen, and high purity air. Hence, alongside being effective, they are quite versatile too.
So, now you might be wondering about where these systems are actually used. Most times, the larger organizations employ the precision plasma cutters to serve their purpose. The individual usually does not use it as they are quite expensive and require a lot of prep work.
- Handheld Plasma Cutting System
The nozzle parts and the electrode of a handheld plasma cutting system generally stay in contact with each other during the ‘off’ state. However, when the user switches the device on, the pressure of plasma gas starts increasing in it.
When that happens, both the electrode and the nozzle parts are forced apart from each other. This, in turn, generates an electrical spark, which switches the air gas into the plasma jet. After that, the DC current flow, within the device, switches to the nozzle from the electrode.
The airflow and current keep continuing until the user releases its trigger.
Components of Plasma Cutter or a Cutting Plasma System
A plasma cutting system or a plasma cutter comes with three different components or parts. Here are some details that you need to know about them. All three components of the plasma system are intertwined, and they work simultaneously in the cutting process. The process may not be realized without any of the three components.
To improve on the quality of the cut, it’s vital to use a shielding cap. This ensures that all parts are held together by inner and outer retaining caps
For us to get a clear picture of how the process evolves, we’ll expound on the basic components of the plasma cutter. Read on.
- Plasma Torch: The plasma torch is one of the main components of a plasma cutter. This part mainly works by providing proper cooling and alignment to the consumables of the machine. The main consumable parts of a plasma cutter are the nozzle, electrode, and swing ring. Sometimes, many users also add a shielding cap with it, improve its cutting quality. So, the plasma torch works by cooling all these sections of the device.
- Power Supply: The power supply of the plasma cutter converts a three or a single-phase AC voltage to a constant and smooth DC voltage. It generally ranges from 250 to 450 VDC. This DC voltage helps in managing the plasma arc during the cutting process.
- Arc Starting Console: The ASC circuit of a plasma cutter helps the device in producing the spark inside of the torch to make the plasma arc.
So, these are some ways in which the different types of plasma cutting systems generally operate.
- A stable power supply maintains the plasma arc
- Plasma cuts by sending an arc through a gas
- The Plasma torch aligns and cools the consumables
Our closing thoughts, the plasma cutting is a well-coordinated process. All components are intertwined for the plasma cutter to work. In case you are wondering, here is a video demo of how it works.