Cold cutting
Stone processors find waterjets answer a lot of their questions about cutting. This is Omag’s answer from UK agent D Zambelis.
Waterjets cut cold, which makes them a good way of dealing with materials with internal tension that can lead to snapping when using a disc. They can also cut just about anything without having to change the tooling and cut intricate patterns. The latest five axes versions are even more versatile as they can produce angled cuts, including 45º mitres, and with rotating heads can produce an even greater variety of shapes.
The Omag waterjets featured here are sold in the UK by machinery, tools and consumables supplier D Zambelis. They are three axes and five axes CNC machines using 29kW KMT waterjet pumps to produce a maximum working pressure of 3800 bar.
Axes X and Y are powered by brushless digital motors driving pinions on hardened helical racks. Linear sphere guides achieve high accuracy movement for precise, fine cuts. The Z axis is equipped with a spherical recirculating screw.
They use Watertag (Taglio) CAD/CAM developed specifically for waterjets and capable of interpolating up to five axes. Together with MagicTool, this provides complete control, facilitating nesting and optimization of cuts or producing simple inclined cuts, such as 45º mitres for drop fronts.
Watertag allows the operator using the 19in touch screen to assign sync points between top and bottom profiles.
Abrasive consumption is a significant cost in the cutting of natural and engineered stones, so needs managing. But by optimizing control of all the system’s parameters, Omag allows optimisation of cutting while minimising the use of consumables.
The cutting unit is assembled on the Z axis guide and consists of a cutting kit that delivers a water and abrasive mix.
There is a probe that maintains a fixed distance between the focuser and the slab to make sure the cut is consistent, even if the surface is not perfectly flat.
That also safeguards the focuser from hitting any previously cut pieces that have been raised against the slab surface because of the backflow of the water.
It is expected these days that there should be automatic compensation for the spread of the jet of water after it has left the focuser. Omag offers software compensation for cutting up to 45º, reducing the cone effect while at the same time increasing the cutting speed.
There are also options of software to display and manipulate digital images of slabs using a camera positioned above the cutting table, a cutting head calibration system, and a sludge vacuum evacuation to remove sludge quickly and economically to minimise maintenance downtime.
