Understanding the Difference Between Plasma and Laser Cutting

Cutting in production and manufacturing is a significant part of the process and is often much faster and more precise than other machining processes. 

This is largely due to the rise in popularity of computer-controlled (numerically controlled) cutting tools such as plasma and laser cutters.

Production cutting can be done by two different methods: plasma or laser. While lasers and plasma cutters both use high-powered beams or rays to cut material, these technologies offer very different benefits for businesses. 

Both have benefits depending on what kind of material is being cut, but there are things to consider before purchasing either type of machine. This article will explain the difference between plasma and laser cutting.

What is Plasma Cutting?

Plasma cutting is a type of metal cutting process where an ionized gas (plasma) acts on the metal to melt it and cut through the material. 

The basic principle behind cnc plasma cutting is that electricity passing between two electrodes can ionize air molecules present in between them. When the ionized air contains enough energy, it reacts with the material that is to be cut.

The air molecules then transfer excessive energy to the material which melts and cuts through it. 

These ions separate into positive and negative particles which are accelerated by the voltage applied between the electrodes, then neutralize themselves by colliding with neutrally charged particles. 

The plasma produced in this process can have varying temperatures depending on the application. 

A small amount of plasma (around 30A) is used for cutting thin sheets while thicker metal requires high temperatures (around 200A).

The plasma cutting torch is made up of an air compressor, compressed air nozzle, ionization unit, and a power supply. The compressed air is used to blow away the molten metal droplets from the piece being cut.

A large amount of heat produced during this process results in oxidation or discoloration of the piece being cut, which is why it is important to use a nozzle guard to protect the plasma cutting torch.

What is Laser Cutting?

Laser cutting is a milling process that uses a laser beam to melt and cut through metal. The actual material being cut does not come in contact with the blade of the machine, which ensures better quality cuts compared to plasma cutting. 

The laser beam can be used to cut through metal with high levels of precision, which are required in the aerospace industry, medical technology, or automotive manufacturing. 

Laser cutting is typically more expensive than plasma cutting because it requires a more powerful machine that operates under extreme conditions.

The basic principle behind laser cutting is similar to other forms of metal cutting. As the laser beam hits the target metal, it is absorbed by certain molecules or atoms in the material which causes them to emit energy. This energy collides with other particles and creates a lot of heat that melts the material.

The molten metal is then ejected from the piece being cut due to an increase in internal gas pressure caused by heat, which leads to the formation of a hole. 

Combining multiple laser beams can produce an effect called vector cutting where the metal is not cut by molten material but rather ejected from the surface at high speeds due to pressure.

Difference Between Plasma and Laser Cutting

The main differences between plasma cutting and laser cutting are the types of machines used, end result, and process.

1. Plasma Cutting vs Laser Cutting – Machines

Plasma cutting involves using a machine with an electrode gap to produce ionized gases which are then sent through a compressed gas nozzle to cut through metal. 

The beam emitted during plasma cutting is between 10,000 and 30,000 degrees Celsius while laser cutting uses machines that operate at around 1,020 degrees Celsius. 

The temperature required for plasma cutting is not high enough to produce the extreme heat necessary to vaporize material like in laser cutting.

2. Plasma Cutting vs Laser Cutting – Process

Plasma cutting only involves melting the metal being cut with plasma, which makes the process faster than laser cutting. 

The slag produced during plasma cutting is not hazardous but it can be an issue when the material being cut also contains materials that are hazardous or combustible. 

On the other hand, laser cutting’s high temperatures lead to the rapid oxidation of metal surfaces, which produces harmful gases like carbon monoxide and other harmful chemicals, which the operator must be protected from.

Laser Cutting

3. Plasma Cutting vs Laser Cutting – End Result

Plasma cutting produces a better cut surface compared to laser cutting because of its ability to melt through most types of metal. 

However, thick metals require high temperatures typically beyond plasma cutting’s capabilities. Laser cutting is commonly used for removing material, engraving, and making items that are delicate or detailed with few sides.

Benefits of Plasma Cutting and Laser Cutting

Plasma cutting is typically cheaper than laser cutting because it requires less expensive equipment. It does not produce any harmful gases so the operator does not have to be protected from fumes or chemicals that are released during plasma cutting.

Finally, it does not require an additional process like cleaning or chemical coating before being assembled into parts for assembly, which is common in laser cutting.

The main benefit of laser cutting is the precision it provides, which makes it a more viable option for complicated parts or assemblies that require very accurate cuts. 

Laser cutting also produces minimal fumes and does not leave any residue on the metal after cutting, unlike plasma cutting. This allows further processing to be done without additional cleaning before assembly.

Overall, both plasma cutting and laser cutting are important manufacturing processes that allow for fast, precise cuts even with thick metals. 

Plasma technology is well-suited for standard metal cutting needs while laser technology produces cleaner results at higher quality. 

Both methods have their benefits but laser cutting is often preferred to plasma cutting due to its ability to produce a better cut surface.

Some things are better left to the experts, and cutting metal is one of them. It can be difficult to know which type of laser or plasma cutter will work best for your application, and in some cases, both technologies may be equally effective. 

With so many different factors to consider when purchasing either plasma or laser cutter, it is important to understand the key differences between these two tools in order to determine which one will work best for your application.