Grades 6–8 · Machines
How can a waterjet cut through a solid material?
A waterjet cutter uses a narrow, very fast stream to remove material along a path. A pump first supplies high-pressure water. Passing through a tiny opening converts much of that pressure energy into the stream’s motion.
In the diagramA fast stream accelerates grains that erodehigh-pressure waterabrasive grainsworkpieceparticle impacts remove material from a narrow path
Pure waterjets can cut some soft materials. For many hard materials, the stream also accelerates small abrasive grains, often made from garnet. Those fast grains strike the workpiece and remove tiny pieces by erosion.
Moving the cutting head traces a line through the material. Water carries abrasive and removed particles away from the cut. The process does not need a heated blade to melt the entire cutting path.
Its capability depends on the workpiece, stream, abrasive and travel speed. The machine also needs to manage the remaining jet after it passes through. A liquid that seems gentle in a tap becomes a manufacturing tool when equipment concentrates energy into a small, fast, controlled flow.
About this explanation
Starting knowledge: Know that moving particles carry energy and that a nozzle can concentrate a flow into a narrow stream.
Sources
- Flow International — How Waterjet Technology Works