The comparison between plasma cutting and laser cutting has been an ongoing discussion for a long time. While each cutting technology have their pros and cons, the predominant cutting method is tend to be laser cutting in the last decade thanks to the rapid advances in the fiber laser cutting technology.
Both laser cutting and plasma cutting are popular metal fabrication techniques. The method you choose mostly depends on the material you intend to cut. While both methods are able to effectively cut your metal parts, they use entirely different techniques to perform that process. Both methods come with their own unique advantages. Which method you should use for your project will be based on budget, tolerance expectations, metal type and metal thickness.
2. Plasma Cutting
The oldest form of cutting, plasma cutting, dates back to the 1950s when it was developed as an alternative to flame cutting which cannot cut metals such as stainless steel, aluminium or copper.
Figure 1: CNC Plasma Cutting
Plasma cutting operates by firing an electrically ionised heated gas (plasma) out of a nozzle at a high speed towards the metal. This will form an electrical ark within the gas. This electrical arc ionizes some of the gas, producing an electrically conductive plasma channel in the process. As electricity from the cutter torch travels down this plasma, sufficient heat is generated to melt through the work piece. High level of heat is generated as electricity from the nozzle travels down this plasma. This heat melts the metal where cutting is achieved.
Due to its aforementioned working principle, plasma cutters can cut any conductive metal including stainless steel, aluminium, brass and copper along with mild steel. It’s particularly ideal for thick metal, up to 50 mm. If cutting highly reflective or very thick sheets of metal is required, plasma should be the ideal cutting method. However, for tight cutting tolerances and high surface finish, laser cutting would be the ideal option.
3. Laser Cutting
Laser cutting uses laser beams to cut metal sheet. It involves a focused beam of laser light that melts or burns. There are currently two types of laser cutting methods; CO2 and fiber laser cutting. Both CO2 and fiber lasers use a laser to create a beam used to cut and fabricate metal, but they differentiate based on the concentration of the beam. Fiber Laser use gas for the concentration whereas Co2 lasers use gas. These technologies perform at different wavelengths, altering the absorption of the laser.
Figure 2: CNC Laser Cutting
4. Comparison of Plasma and Laser Cutting
- Laser cutters require significantly higher investment cost compared to plasma cutters.
- Laser cutters unit operation costs are significantly higher than plasma cutting.
- Laser cutting offer higher efficiency and higher output rate compared to plasma cutting
- Maintenance and operation costs of plasma cutting machines are higher than laser cutters.
- Laser cutting provides a better finish and higher precision whereas plasma cutters have bigger cutting tolerances.
- Plasma can cut thicker sheet metals than laser however due to recent advances in fiber capacity lasers are becoming more capable of cutting thicker metals.
- Plasma is used only for cutting steel, while laser can cut many types of material.
Although fiber lasers require a higher initial investment budget, they offer more effective and high quality output compared to the plasma cutting machines. Traditionally fiber cutting underperforms when it comes to thick material but recent developments in the fibre technology with 15kW machines, steel up to 30 mm can be cut with high precision.