1. HIGH PRESSURE JET CUTTING
• Typical jet size <0.8mm faster than speed of sound.
- destruction of brittle materials
• Typical pressures are 150-1000 MPa and use 8-80 KW.
• Velocities are 540-1400 m/s.
• Typical fluid volume is 0.5 to 2.5 l/min.
• Fluid Pressure Intensifier - hydraulics actuates smaller cylinders, that drive larger cylinders. The larger cylinders intensify air pressure.
• Nozzle - internal diameter reduces 40 to 160 times to the exit tip.
• Cutting - If the material is brittle it will fracture, if ductile or erosive, it will cut well.
• Pulsed cuts can cut deeper, but feed rates must be reduced for acceptable cuts.
• The fluid used must have a low viscosity to minimize energy loses,
• Water most common, but additives such as alcohols, oils, products and glycerol are used, when they can be dissolved in water (ventilation may be required).
• The typical head is shown below. The orifice is often made of sapphire and ranges from 0.05” to 0.020”