30-07-2013, 02:40 PM
WATER JET TECHNOLOGY
WATER JET .ppt (Size: 2.42 MB / Downloads: 254)
Water jet cutter
A water jet cutter is a tool capable of slicing into metal or other materials using a jet of water at high velocity & pressure, or a mixture of water & an abrasive substance.
Introduction to Water Jet
Fastest growing machining process
One of the most versatile machining processes
Compliments other technologies such as milling, laser, EDM, plasma and routers
True cold cutting process – no HAZ, mechanical stresses or operator and environmental hazards
Not limited to machining – food industry applications
Working principle
The cutter is commonly connected to a high pressure water pump where the water is then ejected from the nozzle, cutting through the material by spraying it with the jet of high speed water. Additives in the form of suspended grit or other abrasives, such as garnet and aluminum oxide can assist in this process.
Pure WJ Cutting
Pure cuts soft materials – cardboard, disposable diapers, tissue papers, automotive interiors
Very thin stream (0.004-0.010 dia).
Very little material loss due to cutting.
Can cut thick, soft, light materials like fiberglass insulation up to 24” thick or thin, brittle materials.
Very low cutting forces and simple fixturing.
Abrasive WJ Cutting
Used to cut much harder materials
Water is not used directly to cut material as in Pure, instead water is used to accelerate abrasive particles which do the cutting
80-mesh garnet (sandpaper) is typically used though 50 and 120-mesh is also used
Standoff distance between mixing tube and work part is typically 0.010-0.200 – important to keep to a minimum to keep a good surface finish
INTENSIFIER PUMP
INTENSIFIER PUMP consists two part
① Water circuit
② hydraulic circuit
Intensifier pumps utilize the
"intensification principle.“
Pressure = Force /Area
Made of inlet water filters,
booster pump, intensifier,
and shock attenuator.
filtered by the inlet water filtration system
The filtered water travels the booster pump
intensifier pump and pressurized up to 94,000 psi.
the shock attenuator.
Waterjets v/s Lasers
Abrasive water jets can machine many materials that lasers cannot. (Reflective materials in particular, such as Aluminum and Copper.
Uniformity of material is not very important to a water jet.
Water jets do not heat your part. Thus there is no thermal distortion or hardening of the material.
Precision abrasive jet machines can obtain about the same or higher tolerances than lasers (especially as thickness increases).
Water jets are safer.
Maintenance on the abrasive jet nozzle is simpler than that of a laser, though probably just as frequent.
Conclusion
Relatively new technology has caught on quickly and is replacing century-old methods for manufacturing
Used not only in typical machining applications, but food and soft-goods industries
As material and pump technology advances faster cutting rates, longer component life and tighter tolerances will be achievable
Paves the way for new machining processes that embrace simplicity and have a small environmental impact