Waterjet Machining

Waterjet Machining -- Its Time Has Come
Waterjet machining has been around for many years, but has traditionally been viewed as a specialty process with limited applications. However, recent advances are making waterjet machining practical for applications never before considered.

The waterjet cutting machine uses a stream of water and abrasive particles, such as garnet, to perform the cutting operation. The waterjet cutter takes city water (typically 80 psi), and through the use of an intensifier-type pump, pressurizes the water to 55,000 psi. When the abrasivejet cutting head is enabled, the water flows through a 0.010-inch diameter orifice into a mixing chamber. As the waterjet stream enters the mixing chamber, it creates a partial vacuum that draws the flow of abrasive particles through the abrasive delivery line. The abrasive particles combine with the waterjet stream to create the high energy abrasivejet cutting stream. This stream exits the cutting head at a velocity of up to 3,000 feet per second. Today's waterjet cutting machines are CNC controlled for accuracy, repeatability and ease of setup.

Waterjet machine

Advantages of waterjet machining:
- Cuts through any substance

- Material yield is maximized. Parts can be nested very close to each other in order to maximize material utilization. In some cases, pieces can even share the same cutting line.

- No heat-affected zones the waterjet process does not generate the same level of heat as other processes. As a result, the properties of the materials being cut do not change. The waterjet heat is concentrated so much that it literally dissipates into the chip or removed material. He adds that there will be no burn marks on parts that have been cut by the waterjet.

- No start hole is required The waterjet nozzle is placed where the cutting is to begin. The waterjet burrows its own hole through the material, eliminating the need to drill the material beforehand.

- Burr-free edge quality. The waterjet cuts with very little force, so the amount of burr generated is either very small, or non-existent.

- Eliminates secondary operations. In many cases, the need for secondary operations, such as sawing, milling or drilling can be eliminated. Etching of numbers can be done during the waterjet process, eliminating the need for a separate etching operation. In addition, because the waterjet cuts without heat, there is no need to anneal the material after machining.

3D Waterjet Cutting Technology

The Mach 4 cutting system combines a HyperJet pump, rated at 94,000 psi, with Dynamic Waterjet XD, a high-precision flat stock and 3D waterjet cutting technology. The combination is said to improve part cycle time and accuracy.

The accuracy and speed that Dynamic Waterjet applied to 2D cutting is now available for cutting bevels and 3D parts with the patented Dynamic XD. Now manufacturers can accurately cut a variety of intricate designs, often without any secondary processing.

The HyperJet pump delivers a stream of water at nearly four times the speed of sound, the company says. Increased pressure increases productivity. Waterjets equipped with HyperPressure systems running continuously at 87,000 psi cut as much as 50 percent faster while using less abrasive than conventional waterjets, the company says. Parts can be cut with a lower cost per part, and more jobs can be completed in less time.

3D Waterjet Cutting Technology

Cost-Effective Waterjet Technology
The Hydro-Jet Eco is described as a high-precision, low cost waterjet cutting system. The unit offers a compact design and cuts virtually any type of material including metal, composites, plastic and more.

Equipped with a software package for quick programming on an integrated PC control with graphical user interface, the waterjet technology features a cold-cutting process that ensures distortion free fabrication, the company says. This pure water and abrasive cutting equipment is said to ensure precise cuts without any heat-affected zone. The working area is 60 ″ × 24″ along with positioning accuracy on the X axis of ±0.001 inches per foot and Y axis of ±0.0007 inches per foot, allowing for complex cuts and small kerf widths for better material use as well as seamless nesting.

The Water cut

The waterjet features a maximum feed speed of 160 ipm with a repeatability of 0.0007 inches per foot. The unit comes with an integrated high-pressure 10-hp pump.