Water jet is the most versatile process, because it is able to cut almost any type of material. Limitations include materials that are highly brittle, such as tempered glass and some ceramics.
Water jet is a very precise cutting process. It has a narrow kerf width, allowing fine contours to be cut, and producing high tolerance parts. However, it is a very slow, expensive process when compared to plasma on most metals.
That is why ESAB offers the patented combination of water jet and plasma on the same machine. This option allows you to take advantage of the accuracy of water jet where you need precision, and also benefit from the speed and low cost of plasma where high precision isn’t necessary. The effect is to produce the parts you need for substantially lower cost, in substantially less time.
Water Jet Process Basics
The water jet cutting process starts with an intensifier pump, which creates the ultra-high pressure (over 50,000 psi) water pressure required for cutting hard materials.
The Intensifier pump uses a hydraulic pressure over water system. A large horsepower motor drives a hydraulic pump, creating hydraulic pressure which powers a piston in a cylinder. The hydraulic pressure is amplified by the ratio of the larger hydraulic cylinder pushing a smaller piston into a cylinder filled with water, thus creating the ultra-high water pressure.
The pressurized water is delivered to a cutting head by either high pressure tubing or hose. At the cutting head, the high pressure water is applied to an orifice with a typical diameter ranging from 0.005” to 0.020”. This orifice is made in a diamond or sapphire, to resist abrasion of the high pressure water. The orifice defines and creates the water stream which cuts through the material.
After the water stream exits the orifice, an abrasive can be added to the water stream, to allow it to cut hard materials. When cutting hard materials, including steel, stainless steel, aluminum, stone, wood, plastic, glass, etc., it is the abrasive that does the actual cutting using a mechanical sawing type action.
The abrasive is usually crushed garnet, the same type of material often used as the abrasive on sand paper. Some special applications utilize other abrasive types.
When cutting soft materials, such as rubber, leather, cloth, paper, cardboard, insulation, foam, etc., the high pressure water stream does the cutting, and no abrasive is used.
ESAB manufactures CNC water jet cutting machines for large and small cutting applications, and can customize a machine to fit your exact needs: