The term WaterJet Cutting encompasses two procedures: “WaterJet Cutting” and “Abrasive Cutting”. The two methods are relative, the former using pure water pressurised to 60,000psi and forced through a jewel with an aperture of around 0.1mm and the latter, Abrasive cutting, differing in its incorporation of an abrasive in to the water the moment before it hits the material (in this case we use Garnet, a very hard and sharp sand.) The combination of pressure and abrasive quickly scores through the material with a kerf (cut width) of between 0.8-1mm depending on the thickness of the material.
WaterJet Cutting and Abrasive Cutting are extreme forms of erosion; artificial imitations of naturally occurring aquatic processes. The best example of such forces (and a process identical to WaterJet Cutting) can be seen in the geological formation of waterfalls whereby a combination of fast flowing water and fine particles wear away the rocks, gouging deep canyon styled features into the earth’s surface.
In somewhat smaller contexts WaterJet Cutting uses just a couple of litres of water and a couple of hundred grams of Garnet (abrasive sand) per minute, forcing them through a nozzle of 0.8 at 2045mph (that’s 3 times the speed of sound).
If a part is fairly small, it is necessary to add a ‘micro-tag’ to hold the part in place whilst the material is being removed from the machine. The tag stops that part from falling into the tank. Sometimes this leaves a small pip about 0.7mm big on the part which is can usually be removed with a small file.
This effect is often seen in thicker materials which have been WaterJet cut. As the beam is traveling through the material it is slightly compressed. This results in a very slight taper on the cut edge and is a characteristic of all WaterJet cutting. The deviation is usually about 0.1mm from the top of the material to the bottom depending on the material thickness and the speed at which the part was cut.
Our abrasive waterjet machines can handle material up to 2500 mm (width) X 9000 mm (length)