Abrasive Jet and Waterjet Cutting Heads Information
Abrasive tools and water jet tools use a pressurized jet of water to cut or shape a variety of materials. Abrasive tools and water jet tools generate little heat, cut clean edges without any gasses or oils, and remove only small amounts of material. In addition, water jets and abrasive jets can cut virtually any material, do not generate side forces or mechanical stresses, and do not require tool changes. Cutting water jets may complement other cutting technologies such as electro-discharge machining (EDM), laser cutting, milling, and plasma cutting. Unlike other cutting processes, however, abrasive and water jet tools do not create hazardous materials and vapors. Some products are used in automotive and aerospace applications. Others are designed for stone and tile, tool and die, fabrication, and job-shop applications.
Types of Abrasive Jet and Waterjet Cutting Heads
There are two basic types of water cutting products: abrasive jets and water jets. Both types of water jet tools use water that is pressurized to 20,000 psi to 60,000 psi and then shot through a small-diameter opening (0.007 in. to 0.015 in.) to create a very thin beam of water.
A standard water jet uses an unadulterated stream of water to cut through relatively soft materials such as carpet, paper and cardboard, soft rubber, foam rubber, gasket material, or soft wood. The device uses high-pressure water forced through a small hole to concentrate an extreme amount of energy in a small area creating a high-pressure, high-velocity beam.
Water jet. Image Credit: waterjets.org
Abrasive water jet technology (AWJ) start the same way as a water jet but they inject abrasive particles into the water stream, allowing the abrasive jet to cut through materials such as stone, non-ferrous metal, glass, carbon fiber, composites, nylon, graphite, many types of steel, plastic, hard rubber and ceramic. This tool can cut material while the device is stationary but it is also highly efficient when the jet is moved across the material. Like standard water jets, AWJ tools require few secondary operations and can produce net-shaped parts without heat distortion or mechanical stress.
Abrasive water jet tool. Image Credit: waterjets.org
Abrasive and Water Jet Tool Parts
Abrasive and water jet tools cut with a narrow kerf and use materials efficiently since parts can be nested tightly. Components and accessories include nozzles, compressors, pumps, cabinets, wheels, and dust collectors.
Abrasive and water jet tools are available with several features for optimal performance in the required application.
Dry / Air- The machine uses a stream or jet of air to carry, accelerate, or direct the abrasive particles against the workpiece.
Wet / Water- The machine uses a stream or jet of water to cut, to carry, or accelerate the abrasive particles against the workpiece.
Gravity Feed- The abrasive particles are fed into the nozzle or wheel by gravity for projection onto the workpiece.
Pressure Feed- Pressure pot or vessel contains a mixture of abrasive and carrier fluid (air, water or other). The pressurized air, liquid, or gas in the vessel pushes the abrasive particles into the gun.
Suction / Venturi Feed-The abrasive particles are sucked into the gun, nozzle, or lance through a Venturi generation process. Venturi generators use a fast moving stream to create a vacuum that pulls materials into the steam.
When selecting abrasive tools and water jet tools, specifications to consider include jet pressure, abrasive grain or media flow, traverse speed and power.
Jet pressure is the pressure of the water used to create a jet or blast stream for cutting or propelling abrasive particles.
Abrasive grain or media flow is the rate of flow or feed of the abrasive grain.
Traverse speed is the feed speed of the workpiece as presented to the abrasive stream or water jet.
Power is the mechanical motor power required for driving the pumps or compressors on abrasive and water jet tools.