laser cutting and plasma cutting are widely used for metalwork, however, we often get consufed of which CNC machine to buy — laser or plasma? especially new comer in the field. Actualy, it depends on the specific requirements of your metal cutting project or application.
Though having much in common, the plasma cutting and laser cutting have their unique features and advantage/disadvantage, some main differences between laser cutting and plasma cutting are as shown below:
How does a laser cutter work?
Laser cutting is the production of a particularly high-energy beam through the device, which then focuses the energy through a lens to form a spot. This kind of focusing makes the energy even bigger. Generally, the spot temperature formed by the laser cutting device can reach tens of thousands of degrees Celsius. The material is melted and vaporized instantaneously by the high temperature, and then the high-pressure gas is sprayed through the nozzle to melt the melt. The vaporized part is blown away so that many types of metals can be easily cut.
Plasma cutting, as a cutting style, was developed in the 1950s as an alternative to flame cutting, when working, a superheated, electrically gas is fired out of a nozzle at high speed towards the work-piece. An electrical arc is then formed within the gas. This electrical arc ionizes some of the gas, creating an electrically conductive channel of plasma in the process. As electricity from the cutter torch travels down plasma torch, sufficient heat is thus generated which melts through the work piece while the gas blows away the molten material from the bottom of the cut, resulting in separation of the work piece.
Laser cutting can cut a lot of materials, including stainless steel, iron, aluminum, copper, galvanized and other metal materials, as well as many non-metallic materials such as acrylic, wood, leather. However, since it cuts by beam spot, and the reflectance of non-ferrous metals such as aluminum plates and copper plates is very high and thus is very difficult to cut, the thickness is limited within 6 mm, it is one of the disadvantages of laser cutting.
Plasma can only cut some metal materials such as aluminum plate, iron plate, stainless steel plate, copper plate, galvanized plate, etc., but the cutting thickness is much larger. Generally, the iron plate of 20mm or more can be cut by plasma. Reflection is not a problem for plasma cutting. Thus aluminum and copper plates can be cut. Aluminum plates, which have relatively low density, can be cut faster and easier.
The precision of laser cutting is the highest among many cutting methods. If set properly, the cutting accuracy can be within 0.02mm when cutting some thin plates, thus is suitable for high-precision cutting, also, the heat-affected zone and slit are small. The cutting surface is smooth and burr-free and can be used directly.
The cutting precision of plasma cutting can be within 1mm. other advantages of plasma cutting are the relatively large heat-affected zone and wide slit. It is not suitable for cutting thin plates because the plates will deform under the affect of heat, and the work-piece by plasma cutting needs further processing.
Laser cutting machines, especially high-power fiber laser cutting machines, are costly and therefore the price is pretty high, whiles plasma cutting machines are relatively inexpensive. At the same time, when cutting the same material, the running cost of plasma cutting is much less than laser cutting, because the running cost of plasma cutting is calculated on the basis of time, generally, it is calculated by the quality and thickness of the plate. Whiles Laser cutting is calculated according to different types of holes, lengths, and heights, thus the price is higher than plasma cutting.
How do I decide which CNC machine to buy?
Seen from the differences between laser cutting and plasma cutting, conclusion can be made that plasma cutting is more suitable for rough machining work which has low precision requirements. The price of plasma cutter is cheaper and thus acceptable, whiles laser cutting is high in price but also in cutting quality. Therefore, it is suitable for industries and products which require pretty high accuracy, such as decorative screens, saw blades and various high-precision and high-quality products. Besides, owing to the special working principle of laser cutting, it is not suitable for cutting work of thick aluminum plates and copper plates, thus plasma cutting will have to be selected.