Published 8th May 2017
Are you torn between choosing a waterjet, laser or plasma cutting system? Each cutting system uses a different method to cut material, and each method has its benefits and disadvantages. Read on to find out which cutting technology will best suit your business.
How does a waterjet work?
A waterjet uses a jet of pressurised water to cut, although the water can be mixed with an abrasive to get a cleaner cut with a good edge finish. Laser uses a laser beam guided by mirrors or fiber optics to cut, and the plasma arc cutting process uses electrically conductive gas. This includes argon, hydrogen, nitrogen and mixtures, plus air and oxygen to melt and pierce the metal.
What can it cut?
The waterjet can basically cut anything; stainless steel, Inconel, titanium, aluminium, tool steel, ceramics, granite, armour plate and materials that are sensitive to high temperatures. It can cut almost any shape and thickness up to 10 inches, with precision, creating a uniform and burr-free edge. The waterjet uses the same tool for cutting all types of product, so there is no need to change cutting tools when switching product. This system does, however, produce a high volume of cutting waste and requires a high level of clean up, compared to laser and plasma.
Laser and plasma systems, by contrast, have limits to the materials they can cut. Plasma can be used for cutting metals such as stainless steel, aluminum and copper, of varying thicknesses. It can cut both ferrous and nonferrous metals, but non-conductive materials such as wood or plastic cannot be cut with a plasma cutter. Plasma is faster than laser cutting systems for thickness over 3mm, but a minor drawback is that plasma typically leaves a 4-6-degree bevel on the cut edge; which can be more noticeable on thicker pieces.
The laser is a little more extensive than plasma in the variety of material it can cut. All plastics, glass, ceramics, rubber, wood and most metals can be cut with speed and accuracy with a laser. It also allows complex detail and good edge quality in either sheet, plate, tube or box section.
The laser is more precise than plasma and the waterjet system and uses less energy when cutting steel and aluminum sheets. For thicker materials, the plasma is more likely to be the most efficient cut, although developing laser technology means that laser is not so far behind. However, there is a slight burring with laser and the possibility that the material may deform. The same can be said of the plasma system too.
How does it affect the staff and work environment?
The laser cutting machine requires only minimal human intervention, mainly for programming, inspections and repairs. Therefore, the frequency of injuries and accidents is minimal, although too close contact with the laser can cause burns. Laser cutting of materials such as plastics can cause gas emissions when exposed to heat, which means that a well-ventilated room is vital as the gases can be harmful and toxic.
Plasma cutting too requires only minimal operator training and is easy to operate with no potentially complicated adjustments associated with laser cutting systems. However, in addition to high energy radiation generated by plasma, the intense heat creates substantial quantities of fumes and smoke from vaporising metal, so again, a well-ventilated work area is a must.
The nature of the waterjet process requires that protective equipment is worn, particularly ear protection as the machine generates significant noise pollution. Protective glasses are needed for plasma but for laser safety glasses are not always necessary.
How efficient is it?
Power consumption depends on the type of material to be cut but as a general idea the electrical power use for a 1500-watt laser is 20-40kw, for a 20kw, waterjet system the electrical consumption is 22-35 kw and for a 300amp plasma machine, the electrical power use is 55kw.
It’s not an easy decision to make as there are a lot of factors to consider; the initial outlay and running costs, the efficiency of the system, the impact on your bottom line, not to mention the staff impact. Hopefully we have given you a little more insight into the general benefits and disadvantages of each method so that you can make an informed choice.
Do you intend to use one of these cutting methods? Let us know what your cutting needs are; we may be able to help.