What is plasma cutting?

Plasma cutting has a long history that begins in the 1950s. It is one of the established techniques for cutting electrically conductive materials. To understand how plasma cutting systems work, it is useful to know the basic elements of the process.

How does plasma cutting work?

Plasma arc, also known as plasma jet, is ionized matter in a gas-like state. The presence of ions of different charges and free electrons makes plasma an excellent conductor of electric current, and its resistance decreases as the temperature increases.

The intensity of the current flowing in the plasma makes it possible to distinguish three states. At low current intensity, no light is visible (black current). As the intensity increases, the plasma begins to generate light, forming a plasma arc at its peak. This is used in CNC plasma cutting.

What affects the quality of the cut

Plasma cutting uses different types of gases. For basic equipment, it is air, but high-performance equipment (High Definition Plasma) requires the use of: Oxygen, Nitrogen, Hydrogen, Argon or mixtures of these gases. Each of these gases is used as required:

• Oxygen - most commonly used in the cutting of low-carbon and low-alloy steels. The use of oxygen produces a clean, smooth cut with minimal slag, which is crucial in the machining of low-alloy metals used in the construction and automotive industries.

• Azotium - is ideal for marking and cutting non-ferrous materials such as aluminum, copper and titanium alloys. Nitrogen is an inert gas, which means that it does not react chemically with the material, preserving its original properties.

• Argon - commonly used for plasma marking. Due to its chemical and physical properties, argon is preferred in processes where accuracy and control over the marking process is important.

• Argene-hydrogen mixtures and nitrogen-hydrogen mixtures - used for cutting aluminum and stainless steel. Hydrogen, being a highly reactive gas, when combined with argon or nitrogen, forms a mixture that allows precise cutting of thicker materials such as stainless steel and alloyed aluminum.

Another factor that affects the result of cutting with plasma cutters is current intensity. It affects the high temperature and strength of the plasma arc. The voltage is responsible for making the plasma arc determine the correct course of the machining process.

The diameter of the nozzle, which is responsible for the constriction of the plasma arc, also plays an important role. The position of the torch (plasma torch) in relation to the material, the type, pressure and intensity of the gas, as well as the type and structure of the electrode also have a huge impact on the deposition result.

What is plasma cutting - characteristics of the technology

In plasma cutting, the material is cut by a highly concentrated plasma arc and ejected from the slot using kinetic energy. This allows cutting of all materials that conduct electricity well. The development and continuous improvement of this technology has greatly increased both the range of materials that can be cut and their thickness, as well as the high cutting speed. For example, the difference in burning speed between plasma and oxygen is so great that at a thickness of 3 mm, plasma can replace 5 oxygen burners (Flame Cutting with Oxygen Fuel). At a thickness of 10 mm, the difference decreases 2-3 times. The development of plasma technology has made plasma cutting competitive with processes such as laser cutting under certain conditions. This is made possible by the use of high-resolution plasma. CNC plasma cutting takes place in a shield of rotating gases that confine the plasma arc. The beam is more concentrated, so the edges of the cut parts are less sheared. In addition, less slag is produced during cutting, and parts are cut faster and more accurately. In addition, HD technology uses liquid-cooled torches, which ensures longer part life.

CNC plasma cutting - advantages:

• High cutting speed

• Wide range of cutting thickness

• Very narrow heat-affected zone

• Cutting without preheating

• Small cutting gap

• Possibility to cut thin materials without burning
• Possible to cut thin materials without burning

• Very good quality of the cut surface after the machining process

• The ability to cut thin materials without burning

Plasma cutting systems in action. What kind of materials can be cut with plasma?

The plasma arc, which is responsible for CNC plasma cutting, can be used to machine electrically conductive materials (such as black steel, stainless steel and aluminum). Plasma cutting can be performed manually or mechanized. Plasma systems are prepared to cut sheet metal up to 75 mm thick (manual systems) and up to 160 mm for mechanized systems. Plasma cutting systems are used not only for cutting, but also for marking.

As a CNC cutting machine manufacturer, we recommend various types of our plasma cutting machines, such as plasma-cutting machines with pilot ignition! Also check out our other CNC machines:

• Metal-cutting-plasmas
• steel-cutting plasmas
• Plates for cutting sheet metal
• Plasma aluminum cutting
• CNC plasma cutting for profiles
• Pipe-cutting plasmas

FAQ:

What is plasma?

Plasma cutting can be easily recognized when cutting along a bright arc. It consists of ionized matter that is in a gas-like state. In order for the electrically charged particles to strike the material, it must conduct electricity.

What advantages does the plasma cutting system have over other cutting systems?

The biggest advantage of the plasma cutting system over other cutting systems is its high speed. It can also process a wide range of steels with different alloys and properties from mild steel, stainless steel and aluminum types. The heat affected zone is small, there is only a small cutting gap, and thin materials can be cut without overheating.

What kind of gas is used for plasma cutting?

Ordinary air is sufficient for conventional basic equipment. High-performance equipment requires gases such as oxygen, nitrogen and argon. Some outputs may also require gas mixtures such as nitrogen-hydrogen or argon-hydrogen.