A waterjet cutter is a versatile industrial tool that can perform cuts on a wide variety of metals and other materials. It works by directing a high-pressure jet of water flowing at such high velocity it cuts through the metal or other material. To make the cutter even more effective, an abrasive can be added to the water, and is often necessary when working on metal or stone. If the cutter is referred to as a pure waterjet (or water-only) it indicates no abrasive has been added and is more likely used with softer materials such as wood, plastic or rubber.
Of the many advantages to be gained by use of a waterjet, some of the most prominent are the precision ability of the cutter, as well as the lack of heat employed when using other cutting methods. It is extremely adaptable and can be found in any industry in which cutting, shaping or reaming is necessary.
What are the main aspects of waterjet cutting?
History of waterjet cutting
While the modern waterjet cutters in use today have only been around for a few decades, the use of water to clear material has been around for centuries. As far back as the Roman Empire, miners and builders used fast moving water to flush away loose material.
The first use of a waterjet to cut material was probably in the 1930’s, when paper companies used a steady stream to cut paper and other soft materials. While this technique offered advanced precision and allowed for cutting at an industrial level, the water pressure was too low to be used with harder substances.
In 1970 the Bendix Corporation developed a reliable corundum crystal waterjet orifice, which provided the durability needed for industrial water cutters to be used at scale. From the 40’s through the 60’s, advanced water jet machines were being used experimentally in the aerospace and automotive industries to cut plastics and other high performance materials, but they were not commercially available.
From that point advances in waterjet technology accelerated as one company after the other developed newer and more advanced techniques, such as adding abrasives and the use of automation to allow for greater precision. Today, waterjet cutting is a standard option for cutting aluminum, stainless steel and countless other materials. The combination of accuracy, safety and speed is hard to match with any other cutting method.
Waterjet cutting does not employ the intense heat used in flame-cutting, laser or plasma cutting operations. The high temperatures generated in these fabrication methods will affect the properties of certain stainless steels, aluminum and nickel based alloys, changing the material quality in the heat affected zone surrounding the cutting path. The waterjet option leaves the material in the same condition after processing.
What are the different cutting heads?
Waterjet cutting technology has come a long way from the 70’s when the first viable waterjet orifices became available. Modern waterjet cutters allow for a great deal of versatility, thanks in large part to the availability of different cutting head options. When it comes to standard waterjet cutting, the head is static, and the stream is kept perpendicular to the workpiece. While the supersonic stream of water is capable of cutting even the hardest metals, glass, stone, and composite materials, it lacks versatility.
Thankfully, dynamic waterjet cutting heads offer manufacturers a greater variety of options. A modern waterjet cutting system with a dynamic cutting head allows for precision tolerance control, which results in more accurate cuts, higher fabrication speeds and greater consistency. The articulated wrist of a dynamic cutting head, combined with automated controls, means the machine is able to compensate for both stream lag and taper.
Even greater precision is possible with a multi axis waterjet cutter. Multi axis cutting gives an operator true three-dimensional control. Some of the many advantages include the ability to stack raw materials to allow for several parts to be cut with one pass; the narrow kerf and nested parts mean there’s less material waste. The most advanced machines are designed to handle large production runs with a high degree of repeatability and uniformity.
What are the possible flow rates?
Another factor in the performance of waterjet cutters is the speed at which the water is ejected from the nozzle. All modern waterjets will involve high pressure generated by a pump. There are two main types of pressure pumps, an intensifier pump or a direct drive pump.
The former employs a hydraulic ram and oil to move the water out through a tiny hole. The latter is like the crankshaft of a car, using plungers and high pressure tubing. In both cases, the nozzle focuses the water into a thin beam. The water is so fast, it can easily reach the speed of a jet airplane, as fast as 2500 feet per second.
The typical range of pressure in waterjet cutters varies from 60,000 – 90,000 psi.
What are the different finishes?
When working with aluminum and stainless steel, there are a number of possible finishes available following waterjet cutting. It’s possible to go without any finish, known as a raw finish, as there is typically minimal overspray at the cut line. For more professional finishes, options include a glass blast finish, which will eliminate surface imperfections and leave an extremely fine grain finish.
Another possibility is to use an abrasive pad to polish the surface of the cut. One advantage of this method is that it will leave a rough tooth that will allow paint to take more firmly. Parts can also be placed into a tumbler along with ceramic media; this combination of part, ceramics and water will leave a nice, even finish.
Your Technical Services Professional
Waterjet cutting is a great option in a wide variety of industries. Aerospace, automotive, mining, manufacturing, fabrication and jewelry making are just a few examples. To learn more about how and when to use waterjet cutting with an application, it’s best to work with an experienced material supplier. Clinton Aluminum offers a variety of value added metals fabrication options including waterjet, precision saw, circle saw and high definition plasma cutting operations.
Clinton Aluminum is committed to working with every one of our clients through every step of the procurement process. Call or email today to learn more.
