The CNC water cutting machines are among the most expensive types of equipment as you can pay for a single machine anywhere between $200,000 and $450,000! These machines are heavily popular for 2D cutting of flat metal plates but one thing that makes these popular is the precise cutting. The precise cutting can be done with a laser as well, however, this is much expensive equipment and isn’t precise as cutting with water.
Some of the biggest waterjet CNC machines are used by companies that serve to granite countertops Raleigh requests and handle huge amounts of these projects. So, what should you know about this waterjet cutting? Well, for a start, you should know that you should not play with this and do take this seriously.
The first cool thing is that you will not have the high temperature that can sometimes be a huge problem. Unlike laser or oxy-fuel cutting, the waterjet process does not involve any temperature increase but rather a purely physical activity. It is very similar to laser, but instead of a laser, you can a thin stream of highly-pressurized water that cuts a material.
However, do not get confused and think that itself cuts the material, – it only carries the tiny rocks that are cutting the material. These rocks use garnets in their structure that enable cutting of strong materials like granite for example.
The abrasive hits the flat plate at the high speed, which makes it able to cut through the material. All the abrasives are small and hence has a small mass. Therefore, to be able to cut through the hard material, the abrasives must have velocity and the greater mass, greater the velocity. It means that the abrasives are moving at a high speed, making it possible to cut through.
But, to achieve such a fast speed, there comes water in. It is pressurized to achieve speed. It is the same principle when you squeeze the garden hose and instead of a larger amount, you get a small one but high pressure and faster speed. The same analogy can be applied to this principle.
To make things work, abrasive is mixed with in a waterjet cutting head that pressurizes water up to 60,000 PSI, which means that it travels faster than sound (making it supersonic). The mix goes into the chamber where the stream forms and then goes out from the focusing tube, traveling supersonically.
Therefore, the abrasives, in the mix with water, travel fast under pressure, which makes it possible to cut through hard materials. It is so powerful that only ½ of gallon flowed per minute. But, it is not about the amount, but about the quality or pressure in this case! Though there is a slight amount of heat during the moment when abrasives hit the plate, water is there to keep the material cool.