Water jet machining is a CNC cutting process in which a water jet at very high pressure is used to cut material to make 3D parts.
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What is Water Jet Machining?
Water Jet Machining (WJM), also known as Hydrodynamic machining or Water Jet Cutting (WJC), is a CNC cutting process that uses a high-pressure water jet to cut material and create 3D parts. The high-pressure water jet is strong enough to cut metal, plastic, textile, composites, fabrics, wood, cardboard, paper, tiles, stones, carpets, leather and rubber by cutting a narrow groove in the material. ( Shown in the image below).
WJM is a widely used manufacturing process in Automotive, Aerospace, Food processing, Defence and military, Medical, surgical equipment, Architectural, and mining because it can cut material or shape that is difficult to cut using traditional manufacturing methods.
Although water jet cutting is typically associated with 2D machining, manufacturers use Multi-axis CNC machines and articulated robotic arms with cutting nozzles to cut and create 3D shapes. The food processing industry also uses it to cut and slice food products because it is a more efficient and clean operation than other cutting processes.
Types of Water Jet Machining
Pure water jet machining and Abrasive Water jet machining are the two basic types of WJM processes.
Pure Water Jet Machining
As the name suggests, the Pure WJM uses pure water without add-ons as the high-pressure cutting medium to cut through the material.
Abrasive Water-jet Machining
Abrasive water jet machining (AWJM) uses abrasive particles in the water jet, such as garnet abrasives, silicon carbide or aluminium oxide, to increase the material-removal rate significantly. As a result, metallic, non-metallic, plastic and advanced composite materials of various thicknesses can be cut in single or multilayers without compromising accuracy. AWJM machine controls the level of abrasives and uses nozzles made of rubies, sapphires, and diamonds to achieve the optimum cut.
Key characteristics WJM
- WJM is ideal for heat-sensitive materials that cannot be machined using heat-producing processes
- The process may not be cost-effective for applications requiring high production rates due to low cutting speed for metal or thick material
- Complex three-dimensional parts can be machined economically to finish dimensions using multiple-axis and robot-controlled machines.
- Pressures of around 350 – 400 MPa (50000 – 60000 psi) are typically used for efficient operation, though WJM machines can generate pressures of up to 1400 MPa (20000 psi).
Water Jet Cutting Applications
WJM is ideal for heat-sensitive materials that cannot be machined using heat-producing processes.
- Architectural / Design /Artwork
WJM technology is widely used to cut glass. The process can cut glass up to 180 mm (7″) to create parts such as glass mirrors, glass partitioning, glass splashback, and architectural applications. Even 3D intricate cut designs can be placed on a glass workpiece using the 5-axis waterjet cutters.
Water jet cutting can cut any metal, including aluminium, hardened tool steel, titanium, copper, brass, and other exotic metals. Water jet cutting preserves the workpiece’s structural and chemical integrity because it doesn’t raise the temperature.
Water jet cutting’s maximum cutting thickness varies depending on the metal. Aluminium – 450 mm (18″), Steel – 300 mm (12″) and Brass and Copper – 250 mm (10″).
Traditional machining of plastics produces toxic fumes due to cutting tools getting hot. As a result, water jet cutting is one of the safest options for cutting plastics because no temperature rise occurs. In addition, the process can cut up to 100 mm (4″) thick toughest acrylics.
Composites like fibreglass and carbon fibre can crack or strain during traditional machining. Because the force is limited at the impact point, waterjet cutting is one of the best cutting technologies for composites. Maximum cutting thickness – 150 mm (6″)
Because of their toughness, ceramics are difficult to machine and frequently require costly saw blades. Hence water jet cutting is a less expensive technique for ceramic machining, and it can cut ceramics up to 200 mm (8″) thick.
Foam and Rubber
Rubber, like plastic, emits toxic fumes at high temperatures. Therefore, manufacturers use waterjet cutting worldwide to process rubber because of its safety benefits. The maximum cutting thickness supported by this method is 250 mm (10″) for rubber and 750 mm (30″) for foam.
Stones, Tiles, Textiles, Paper, Cardboard, Food, Plasterboards,