The contest for industrial cutting is often portrayed as a two-horse race between old-fashioned oxyfuel and the (relatively) new kid in town, plasma. But that is to disregard two very competent performers with their own special abilities: CNC laser cutting and waterjet cutting.
Let’s look at these two objectively and see how they can be of use in the industrial cutting world.
Laser Cutting: Do You Expect Me to Talk?
“No, Mr Bond. I expect you to die.” The invention of the laser in the 1960s came in very handy for filmmakers looking for a futuristic instrument of threat. Lasers were clean, clinical, unfathomably powerful and somehow otherworldly. Forget brute force, that belonged to another age. Lasers could do anything, and even if most people didn’t have a clue how they worked, that didn’t matter, because they weren’t made for the public to use.
The word laser is an acronym: Light Amplification by Stimulated Emission of Radiation. It’s about electrons in atoms absorbing charges from electrical current or light. That is complicated enough to put most people off delving into it any further, and like many scientific ideas, there is no real reason why we should look into it: if it works and does a particular job, great, let’s use it. The researchers and the government will look into the safety aspect and as long as it is certified as okay to use within certain guidelines, that’s fine.
Lasers, we were told, are perfectly safe if used correctly and appropriately—and so it has proved to be—because these things tend to show themselves over time.
Lasers can be used for pointing in situations such as classrooms, and the lower-powered ones are harmless, which is obviously why they are allowed to be used in that way. More power, though, means potential danger, and this power can be increased exponentially to the extent that it is used in industrial cutting.
Benefits of Using a CNC Laser Cutting Machine
Laser cutting is excellent for details and very precise work and is therefore widely used in making smaller parts for electronics and medical equipment, for instance, but also for vehicle parts. CNC stands for computer numerical control, which simply means a computer can be programmed to carry out the work, repeating even complex shapes and patterns exactly.
In addition to cutting fabrics and wood for furniture and decorative applications, with its potentially gentle nature it can be used for etching, making it very useful in sign-making as well as the clothing trade.
At the heavier end of industry, CNC laser cutting machines can be used with metals including iron and steel, at thicknesses as much as 30mm depending on the power of the cutting machine. Laser can deal with plastics and wood too—materials which are not conductors of electricity and therefore do not respond to plasma cutting, and because lasers can be focused so precisely these softer, heat-vulnerable materials are not ruined as they might be with the heavier touch of, for instance, oxyfuel cutters.
On the other hand, laser cutting is not ideal for the real grunt work, the heavy, thick challenges of industrial steel. The machines are also relatively expensive.
As a bonus, laser cutting machines use less energy than other methods, giving them a healthy tick in the ecology box.
Water Cutters: The Unlikely Heroes
While water can be a mighty force in some forms—the ocean and waterfalls, for instance—it doesn’t spring readily to mind when it comes to cutting. But that is to underestimate it. Given a little help from an abrasive, water can be used at high pressure to cut metal, stone, glass, wood and plastic. The most commonly-used abrasive is garnet, better known as a gemstone but having the right characteristics to operate as a high-powered enforcer when pushed through a blasting nozzle.
Garnet is also good because it can be recycled, which adds to the water-cutter’s general characteristic of being a pleasant thing to work with. It creates a clean cut with just a little debris to be removed, and there is none of the potential heat damage that can be caused by oxyfuel, laser and plasma. Waterjet cutting does not produce harmful waste or toxic fumes.
In this way, the development of waterjet cutting was a brilliant piece of lateral thinking which provided a counterintuitive solution for certain cutting needs.
On the negative side, waterjet cutters can be expensive and the process can be slower than heat-driven methods. They are also relatively noisy, because we’re dealing here with abrasion, which means solid material hitting other solid material, even though the abrasive material is in very small particles.
Because waterjet cutting produces smooth edges, this can save time on further work to get rid of roughness.
It could be argued that thickness is not an issue with waterjet cutting, but thicker material will result in slower work.
The use of water in this cutting method brings a certain amount of criticism in relation to using this precious resource, particularly in parts of the world where water is relatively scarce.
The Conclusion: It All Depends
Both waterjet cutting and CNC laser cutting machines have distinct strengths and limitations, so it’s important to consider the type of work you’ll be doing most often before deciding which method suits your operation best.
If one process can meet all your cutting requirements, that’s the ideal scenario. However, many workshops find that using a combination of technologies delivers the best results. Once your investment has been recouped through consistent output and productivity gains, the machine quickly becomes a profit-generating asset.