How Does Abrasive Waterjet Cutting Work?
The customer submits a drawing, blueprint, or electronic file. HezRock then scans, digitizes, or loads the file or drawing with AutoCad. The customer's drawing is then converted into a language that HezRock's waterjet machines can read through a process called CAM (Computer Aided Manufacturing).
A waterjet machine has essentially two components: the x-y-z table which moves the cutting head over the material and a high intensity pump that generates 55,000 psi. At this pressure, water alone can cut plastics, foam, wood, resilient floor coverings, rubber and similar soft substances. The cutting head is a nozzle with a .050 (1/4") sapphire crystal orifice through which water is forced at three times the speed of sound by the high intensity pump. The movement of this nozzle is determined by the computer instructions the machine follows (the customer's drawing).
When cutting harder materials such as metals, stone, ceramics, glass and dense composites, a garnet abrasive is fed into the waterjet stream for stronger erosion action. The waterjet stream does not exert pressure or heat on the working material.
The advantages of this process extend beyond its cost-competitiveness with other cutting techniques. Waterjet allows for complex and difficult shapes, such as inside corners, notches, architectural and artistic shapes, to be cut with equal ease and with a high level of accuracy and precision. Because this is a CAD driven process it also offers the capability of repeatability, not available with most other cutting methods.
Waterjet can be used for cutting composites and plastics that cannot tolerate heat, mechanical damage or delimitation. There are no molding or tooling costs associated with waterjet.
The CAD-CAM process and narrow kerf (or cut) resulting from the waterjet allows for exceptionally efficient usage of expensive materials such as titanium, composites and optical glass. The narrow kerf allows for optimum yield due to nesting (tight tolerances +/- .010 inches depending on the material). In addition the process provides mass production capability with CAD/CAM repeatability. Parts can be manufactured by simply reentering previously run computer programs.
