Laser Cutting Vs. Plasma Cutting
A question we often hear is, "Should I use laser cutting or plasma cutting for metalworking?" As a metalworking company, we have the knowledge and skills to be able to provide you with professional advice based on your budget, needs, and end project. Today, we wanted to take a moment to talk about the differences between laser cutting metal and plasma cutting, and on which projects we would use each of these technologies.
Laser Cutting
A laser cutter is essentially a concentrated beam of light (yes, a laser cutter is essentially a lightsaber). The high-powered beam quickly heats, melts, and partially vaporizes the metal or other material it comes in contact with.
Plasma Cutting
The plasma cutting method involves a highly concentrated conductive gas channel that acts as a vessel to transfer energy from a power source to the material being cut via a plasma torch. Like laser cutters, plasma cutters ultimately cut metal by melting it.
Comparing Laser Cutting and Plasma Cutting
Lasers are generally more expensive to operate, but offer a level of detail that plasma cutting does not. Therefore, lasers are great for engraving details or cutting small shapes out of metal, while plasma is better suited for simpler cuts.
Plasma cutters can cut thicker sheet metal.
Plasma can only cut conductive materials, while lasers are used to cut wood, plastic, glass, and other materials. This is because plasma uses a conductive gas instead of a beam to cut.
Lasers cannot cut highly reflective materials such as copper, so plasma cutting may be the best choice for such materials. However, plasma can cut any conductive metal, regardless of the surface.
Laser cutting is ideal for precise cuts or parts with intricate cuts.
Types of Laser Cutting
Many industries have harnessed the power of laser cutting and applied it to a variety of materials, including wood, glass, stone, plastic, and sheet metal. Currently, there are three main types of lasers used for laser cutting:
●CO2 lasers
●Fiber lasers
●Crystal lasers
Additionally, there are many different types of cutting methods used to cut different materials. Some of these methods include:
●Vaporization cutting
●Melting and blowing
●Thermal stress cracking
●Invisible cutting of silicon wafers
●Reaction cutting
Benefits of laser cutting
●Precise edges - When cutting with traditional methods, such as blades, you often see burrs or rough surfaces that need to be sanded and smoothed. When cutting with a laser, this is not a problem.
●Precise details - The laser beam does not wear out. This improves accuracy. Additionally, due to the size of typical lasers and the fact that they are guided by high-performance computers, this makes it possible to create complex designs that would otherwise be impossible to create.
●Low maintenance - Traditional cutting methods require regular maintenance and blade sharpening. Lasers do not require this kind of maintenance and can run for long periods without repair.
●Maximum Efficiency - Whether you are prototyping or going into full production, lasers never need to be adjusted or re-adjusted. This allows for optimal efficiency when manufacturing.
●Versatile - Laser cutting is capable of cutting a wide range of materials and thicknesses.
●Quick Setup - Compared to other metal cutting techniques, laser cutting has a relatively quick setup time. It is also much easier to make adjustments when custom manufacturing is required.
Plasma Cutting Overview
Plasma cutting is a technique used to cut conductive metals such as steel, brass, titanium, copper, aluminum, etc. Plasma cutting is not only done in metal fabrication shops using large CNC plasma cutters. It can also be done manually using a handheld plasma torch (sometimes called a plasma arc, plasma cutter, or plasma gun).
How does it work?
Plasma cutting works by sending a rapid stream of hot plasma into a conductive metal. This hot plasma is created through a process where an electric arc is fed into a gas such as nitrogen or oxygen. When the plasma stream hits the metal, recombination occurs, causing the gases to return to their normal state, giving off intense heat. It is during this interaction that a fourth state of matter is created. We call this state plasma.
Why use plasma cutting?
Metalworkers prefer plasma cutting for a number of reasons. Here are just a few:
●It is safer than using a saw
●Can cut thick metals and a variety of surface types
●Provides extremely precise, fast, and repeatable cuts (when used with a CNC machine)
Tips for choosing the best plasma cutter
●Determine its purpose. What materials will you be cutting with plasma? What products do you plan to produce with plasma cutting? Plasma cutters are amazing and versatile tools, but you need to make sure the one you buy is powerful enough to handle the work you will be doing. These questions will narrow down which plasma cutter is right for you.
●Consider the cutting speed. The cutting rate will tell you how fast a plasma cutter can cut through different thicknesses of metal. Additionally, a plasma cutter with a higher amperage will be able to cut metal faster than one with a lower current, although both will get the job done. Plasma machines typically have three cut ratings: rated, quality, and cut. This also tells you the thickness of metal the machine is capable of cutting.
●Consider how the plasma cutter will start. Most plasma cutters have a pilot arc that uses high frequency to conduct the current through the air. Plasma cutters are easier to start, but the high frequency may interfere with nearby computers and devices. High-frequency cutters are cheaper and produce a more stable arc, but they are limited in that they require scratching close to the metal to start.
●Weigh the cost of materials. Due to the nature of plasma, plasma cutting torches have many parts that need to be replaced periodically. If you are using a handheld torch, you will have to replace the retaining cap, shield, nozzle, electrode, and swirl ring. All of these will affect cutting performance once they begin to deteriorate. Logically, the fewer parts there are, the fewer parts will need to be replaced, and the lower the overall cost in the long run. Some manufacturers will give you an estimate of the life of the parts.
Not sure which cutting torch is right for you?
At the end of the day, no two projects are alike. Time and budget constraints will influence whether we use laser CNC machine services or a plasma cutter. Additionally, the thickness of the project and the level of material and detail required will all influence how we achieve the final product. If you have questions, please feel free to ask us.