Advantages of Waterjet Cutting Machines

Waterjet cutting machines tend to be the most versatile of all cutting machines. They can handle almost any material, from hard to soft, in any shape and size. It may be surprising, yet waterjets can indeed cut through extremely tough materials.

Diversity of Materials

Unlike almost any other method of cutting material, waterjet cutting does not involve heat, directly or indirectly. As a result, minimal material deformation occurs – there is no "heat-affected zone." Waterjet cutting is a cold cutting process.

Many kinds of materials are susceptible to temperature change. Plastics and rubber will melt and change their shape under excessive heat. Carpeting and textiles are flammable. Many materials give off harmful fumes when heated.

Waterjet cutting offers an attractive option if food needs to be cut because no blade needs to be cleaned. The jet of water is sanitary.

Ceramics are notoriously difficult to cut because of their toughness. Special, expensive blades are needed and must be regularly replaced. Adding an abrasive to the waterjet enables WCMs to handle ceramics at a cost-effective price point.

Steel, titanium, hardened tool steel and other metals are cut well by waterjets. Because waterjet cutting does not raise the temperature of the material, internal stresses are avoided, and the material's structural integrity is preserved.

Glass cutting is tricky using conventional methods because it easily cracks and chips. Waterjet cutting handles glass very well and is commonly used for this purpose.

Cutting stone is an excellent application for WCMs. With the addition of abrasives, WCMs can make precise cuts in almost any kind of stone.

Cutting wood with blades can generate a ragged edge and airborne dust particles that are problematic. The user can solve these problems with waterjet cutters. Some manufacturers may shy away from using waterjet cutting for wood because they fear damage to the wood from water absorption. However, waterjet cutting is effective without causing any damage due to water absorption because the water stream is so highly pressurized and moves with incredible velocity. And the cuts are clean with little to no tear-out.

In terms of water absorption, it is interesting to note that the first commercial application of waterjet cutting was for corrugated cardboard! Cardboard can, of course, be easily damaged by water, yet the waterjet cutting does a great job.

Reduction of Secondary Operations

Other methods of drilling or cutting usually leave burrs. These ragged edges need to be ground or sanded down, requiring additional, secondary processing time. Waterjet cutting leaves few to no jagged edges behind – the cut is clean. Secondary processes such as sanding and deburring are eliminated or minimized by WCMs.

The result is a more productive operation for a manufacturing business.

Safer and Environmentally Friendly

With most other kinds of cutting, the user faces safety and environmental challenges. CNC machines emit metal particles, saw blades create dust and particles, and laser cutting can result in fumes because of the heat.

WCMs are environmentally benign because they use a cold cutting process. The water used in cutting is recycled, so the amount of water used is minimal.

Depth of Cut

A waterjet cutting machine can cut relatively thick material – much thicker than most laser cutters. The exact thickness varies according to the material and the setup. Charts are available to give the user detailed information about the thicknesses possible.

Some manufacturers advertise that they can cut materials with a WCM up to 24 inches thick. A waterjet cutter can even cut through a 10-inch-thick steel plate using abrasives.

Detailed Part Geometry

Waterjet Cutting enables the user to generate very detailed and complex parts. Because there are no heat-affected zones, no mechanical stresses are applied to the material's internal structure, which allows for fine detail.

Ease of Setup

The waterjet cutter does not in general require different tools the way CNC machines do. This eliminates time spent changing tools.

Also, the clamping force on the work material for a WCM is less than is required for CNC milling machines.

Cost

Niels Korsager, a consulting engineer with Gain & Co, estimated that a fiber laser cutting setup might run about $500,000. A carbon dioxide laser cutter could be 30% less expensive, and a waterjet cutter could be half as much as the fiber laser setup.

So, a waterjet cutter can be an attractive alternative to the more expensive laser cutting machines.

In addition, your electricity costs will likely be lower with a waterjet cutting machine than with a laser cutting setup.

Advantages to Cutting with Waterjets

While the advantages to WCMs are many, there are some disadvantages.

Precision

According to Korsager, "the accuracy of a waterjet cannot compete with a CNC milling machine or a laser cutting setup. A CNC milling machine can do 0.01 mm accuracy, whereas the waterjet can achieve about 0.2 mm in tolerances." You can be even more precise with a laser cutting machine than a CNC machine.

So, if high precision is necessary for your application, you're better off using a CNC machine or laser cutting setup. However, for a very wide variety of applications, the precision of the waterjet cutting machine is appropriate.

Speed

When cutting a relatively thin sheet of material, a laser cutter will be faster than a waterjet cutting machine.

On the other hand, because a WCM can cut deeper than lasers, this speed deficit can often be compensated for by stacking sheets of material on top of each other. In that case, you're cutting out several sheets at once.

Another approach to narrowing the speed gap is to use multiple nozzles simultaneously. For cutting parts out of sheets, this can be very effective.

Cost of Nozzles

One disadvantage to using waterjet cutting machines is that the high-pressure water nozzle wears out relatively rapidly and must be replaced.

Korsager advises that carbon dioxide lasers will have cutting heads that also need replacing, although this is not an issue for fiber laser cutting setups.

The nozzles wear out more quickly when abrasives are added to the water stream.

Using Robots with Waterjet Cutting

Since most applications for waterjet cutters are for cutting sheets of material, a 3-axis XYZ type mechanism is the most common type of setup.

However, it is certainly possible to use robot arms with more degrees of freedom to cut more complex objects. An example is the cutting of automobile interiors. An articulated robot arm enables the waterjet cutter to follow the contours of the inside of the car passenger compartment to cut the material to shape.

Automating other parts of the workflow – intake, outflow

Apart from the different kinds of robots that can wield the waterjet cutting nozzle, other aspects of the workflow can be automated.

Robots that lift and put the sheets of material into place for cutting are quite useful and further automate the process. Once the cutting has been accomplished, another robot arm could be used to remove the finished parts, stack them, or place them onto a conveyor. The outflow robot arm could also pass the finished pieces onto an Autonomous Mobile Robot (AMR) for transportation to another part of the factory.

Typical Applications and Industries that benefit from WCMs

Any cutting or drilling done on sheets of material is a potential application for waterjet cutting machines.

According to Grandview Research, the automotive and metal fabrication sectors are the two largest industries using WCMs. Electronics are a close third, and the aerospace sector after that.

Many other industries use waterjet cutting machines, including stone, glass, wood, rubber, and plastic manufacturers.

Factors Preventing Adoption of Waterjet Cutting Robots and How to Overcome These Issues

Many issues can stand in the way of adopting waterjet cutting and robotics in your company. One concern might be uncertainty regarding the superiority of one technology over another. You may find it helpful to talk with people who have seen companies similar to yours successfully implement waterjet cutting. Although discussing things with vendors can be valuable, sometimes a more impartial viewpoint is needed.

You can reach out and confer with an unbiased and knowledgeable advisor from HowToRobot who can provide guidance free of charge.

To help calculate return on investment, HowToRobot also offers tools such as an online investment calculator to assist in estimating savings and ROI.

One of our customers commented, "We used to think that robots and automation solutions were out of the question for a smaller company like us. This program has completely changed our view on automation. When there is a structured approach to follow and advisors to trust, we don't have to be the robot experts. Now we know what we can achieve from automation – and how to get there."

You may know exactly what you want, yet it is still time-consuming to find relevant vendors and contact them. To help with this, HowToRobot has the world's largest directory of robot suppliers. You can search our directory for your application and get a list of relevant vendors in no time. And you can use HowToRobot to get quotes so you can compare prices on anything robot-related.

Perhaps you have an application in mind, but you are unsure if the technology is mature and exists to address it. Or, you might be unclear how to translate your needs into proper requirements for suppliers. HowToRobot offers an automation journey with a structured process.