The high pressure water jet cutting is a still possibility to produce packing. Here you are able to cut very complicated contours. The high pressure water jet cutting technology are use mostly in cutting very hard material like stone and metal. With this technology it is possible to produce very complicated forms.
So a machine is consisting of a high pressure pump, high pressures pipe, the nozzle, the cutting table, the step engine and the catcher.
The high pressure pumps task is to make the high pressure, which are necessary to use the water jet as a tool. This is produce by the pressure transmitter while the till too 200 bar high oil pressure is increase up to 20 fold by the hydraulic pump. This pressure work to the water, which is carry though the high pressure pipes to the nozzle.
Picture IV.11: picture 4.1-1 High pressure pump [5]
For the cutting of Styrofoam you need only a pressure at 400bar. That means that 4 litres per minute come out of the nozzle with 800 m/s (that's 2.5 fold speed of sound) and the force is cut the material. Though the high energy the stuff is not go out of shape and you have a smooth cut. After the bundled has cut the material, the water is catch up by the catcher. This has not only the task of store the water but also they has to absorb the rest of the energy of the water jet.
Picture IV.12: picture 4.1-2 Water jet nozzle [5]
The water has to clean and soften before, when you want avoid downtimes of the machine and of the pump. The pressure can adjust. The adjusting range is dependent on the nozzle diameter and the nozzle number, so the pressure have lower if the nozzle number is higher ore the diameter is bigger. The feet of the cutting Styrofoam can be till 200m/min.
Of course the process technique has limits. The maximum of the cutting depth is 50 cm if you want a accurate cut. If the work piece is more thick, then you get the follow cutting picture:
Picture IV.13: picture 4.1-3 cutting picture after 56 cm