Much larger water jet cutting machines are in demand, such as a profiling machine of 4m x 18m long, which is to be supplied to a German rolling mill, and another operating at a sheet steel mill.

Although offering an unprecedented range of more than 90 standard waterjet profiling machines, all based on the concept of portal design and employing high tech components and systems, Water Jet Sweden now finds itself firmly-established as a market leader meeting a surge in the new demand for much larger capacity installations where machines need the table to be at least 6m long. * Germany leads the way - a good example is the 4m x 18m long WJS profiler, believed to be the biggest in Germany and probably the world, currently under construction and due for delivery before the end of 2006 to the steel rolling company Dillinger Hutte. Not only can Water Jet Sweden's machines such as these handle very large workpieces, thanks to easy transverse access through the portal, but can perform also water jet parallel profiling operations by using several cutting heads mounted along the cross beam.

Moreover, large format machines enable the principle of a divided cutting table to be put into practice, thereby creating an even more economical operational regime.

* WJS installation with workpiece area of 4.2m x 9.2m - Universal Iron and Steel, based in Neuss, is one of Germany's largest retailers of unfinished sheet metal in the steel industry and has a current inventory of 80,000 tonnes, along with a monthly turnover of around 20,000 tonnes.

The branch site at Viersen is concerned exclusively with the processing of refined steels and it stocks up to 1,300 tonnes of various grades of steel at any one time.

The traditional thermal cutting procedures, such as underwater plasma cutting, could handle sheet thicknesses in the 6 to 150mm range.

The Water Jet Sweden NC4492-D now installed is the only one in Germany with a maximum workpiece area of 4.2m x 9.2m and a maximum cutting area of 3.6m x 8.5m.

The machine has now been in operation for several months and is set up for cutting sheet thicknesses from the required maximum of 150mm down to a new low of only 0.5mm which brings great flexibility to the user.

Said Manfred Salg, Universal's branch manager of Refined Steel services, 'Universal is currently the only company in Germany able to cut its whole range of refined and special steels to this desired dimension and precision in-house.' Salg said, 'The main reason for this investment into waterjet cutting was to enlarge our range to include heavy-duty materials such as nickel and cobalt alloys, as well as titanium and titanium alloys.' He added: 'However, this was dependent upon finding an effective and economic process that would fulfil the requirements of cutting quality and tolerance without heat reaction or delay.

We needed also to 'machine' the largest possible format from our classic refined steel product range and this extends to 3.5m wide by 8m long.' Other machine choices were out of the question, as they could not meet the desired specification and, additionally, the quality of the test pieces cut proved decisive.

* 'Side-by-side' cutting - another advantage is that the portal construction of WJS profiling machines makes for easy side-by-side cutting.

Thus, for example, the machine can be set up easily with four cutting heads.

This allows a marked increase in production - without loss of quality.

The high cutting quality, even in very thick materials, is due, amongst other things, to the patented construction of the cutting heads.

Moreover, they use up to 20% less abrasive material than comparable machines.

The machine comes equipped with collision and height sensors as standard, although this is not so important for Universal, as hardly any curvature is involved - something that would be different with plasma cutting because of potential heat distortion.

Guidance of the unit comes from an especially-developed GE Fanuc 310i CNC control system.

Cutting pressure of up to 4,200 bar is provided by two Bohler Dynatronic 424 high pressure pumps.

One interesting point for the business is that the operating area of the Z-axis is up to 250mm.

This allows for the cutting of pieces thicker than 150mm for aluminium and titanium.

* The largest in Switzerland installed by Water Jet Sweden - the Swiss company, Stahl-Contor, Zurich, since 1929 has successfully-established itself as a specialist in the working of and trade in stainless steel.

As such, they have gained a renowned reputation for competence among an ever-increasing number of satisfied customers.

As the leading supplier in Switzerland of various types of highest strength steel plate as used for armoured tanks, cranes, bridges, etc, an investment in waterjet cutting required the closest scrutiny of the system in order to ensure both maintaining and improving the high standards of quality and efficiency expected of them.

Having decided these necessary standards could be met by Water Jet Sweden, a five-axis WJS NC 3592 machine was ordered and installed at the beginning of 2006, which marked the start of a fruitful partnership between customer and supplier.

The installation, one of the most advanced and largest in the whole of Switzerland, having a workpiece of maximum size area of 3m x 8.5m, has more than justified its selection, whether for single part or mass production, semi-fabrication or finished components, and whether from just a sketch plan, drawing, or CAD system.

2D or 3D cutting heads facilitate economic parallel cutting.

Stainless steel is cut to a maximum thickness of 150mm.

Jet pressure of more than 4,200 bar guarantees clean cutting and high precision.

Accuracy tolerance of less than 0.1mm fulfils all the requirements of not only the sheet metal industry in general, but also those engaged in plant and machinery building and the automotive industry.

* A WJS profiler with four cutting heads plus linear drive for workpieces 4m x 6m - earning its keep at Schroeder Schneidtechnikin Guetersloh, is the latest machine from WJS, the new NC4060 Quad.

The first of its kind in Europe, it combines high-precision linear drives with four side-by-side cutting heads.

This company began a contract-cutting service in the waterjet sector six years ago and also offered rapid prototyping of pieces.

Materials dealt with range from metals such as refined steel and aluminium through plastics and ceramics to 'sandwich' construction parts.

Prior to installing the WJS machine, all work had been carried out on a two-three shift system on a 2m x 4m machine with two heads.

Frequent re-adjustments of the machine were needed and managing director, Raphael Schroeder, also had to decline opportunities for producing larger parts.

* Close tolerance accuracy of +/-0.05mm - the WJS machine was able to resolve these problems.

After various test cuts on different companies' machines, the decision came down to the precision that could be achieved cutting special small springs to a tolerance of +/-0.05mm.

The competition was won by the WJS NC4060Q.

The customer asserts that these test pieces had never been cut so precisely before.

Schroeder explained, 'The purchase of this machine was without question a major investment for us.

It offers though the advantage of improved economy, noticeably greater accuracy and the ability to handle much larger workpieces.

Another important factor in our decision was that we could specify the high pressure pump of our choice.' * Virtues of linear drive - cutting precision was due not only to the quality of the Swedish machine, but also to a significant innovation - the linear drive.

Above all, an expensive linear drive makes sense only when used in conjunction with multiple cutting heads whereby they will all cut identical contours over long periods of time.

This is the reason that the WJS NC 4060Q is equipped with four abrasive heads.

Compared with a rotary motor with ball-driven spindles, linear drive offers greater precision, minimal wear and tear and no need for attendance.

Because of the construction of the linear drive, movements are carried out in the most precise way and all other sources of faults, such as gearing, linkage, transmission drive and ball-driven spindles, are avoided.

This results in a noticeably greater accuracy of contour compared with the spindle drive, particularly over a long period of work.

'And that was precisely where we always had problems in the past,' said Schroeder.

* Automatic adjustment - one of the most important points before starting a job is the setting up of the cutting head(s) clearance.

There are still many basic models on the market with manual adjustment.

The more expensive machines, however, use an automatic adjustment with this axis becoming fully CNC.

Linear drive, in conjunction with a corresponding guidance system, offers far greater flexibility and here, the Fanuc CNC control system is used for all drives.

During cutting, the correct clearance of the cutting heads is automatically taken care of by a mechanical height sensor.

A further advantage of this guidance system is the convenience of remote monitoring of the machine.

Even the smallest machine from Water jet Sweden comes with a Fanuc guidance system as standard but NUM-Schneider or Siemens systems are available if requested.

The patented cutting heads are an economically important aspect of all WJS machines: they consist of only three parts; the mixing chamber is located in the pipe and, compared with other machines, uses 15-20% less abrasive materials.

The benefits of this are very noticeable when purchasing and disposing of the abrasive material.

'The machine has two further special features,' said Schroeder proudly, 'A special device for removing the silt, which sucks it out from around 40 places, and an additional removal tank for regulating the water level.

Thus the machine has been custom-built to our exact requirements.' * WJS profiler 3 x 6m long 18 tonnes capacity with divided table - with a 6m long table generally recognized as the starting point for 'large' profilers, some of the above-mentioned advances are featured also in the Butzbach factory of CAN Industrieservice, where WJS has installed a typical 3m x 6m profiler.

Established in 1997, and traditionally using oxy-fuel and plasma devices, CAN produces rotating and non-rotating components for the pharmaceutical and oil industries, as well as for sewage treatment.

However, in contrast to previously used thermal techniques, waterjet is a cold cutting process and is the only method of cutting such a wide range of materials with great precision and without burrs.

Materials can range from refined steel and aluminium to plastics, ceramics and even 'sandwich' style combinations of materials.

There being no residues from heat-affected or melted zones, no microscopic cracks are formed on the cut edge.

CAN-chief, Mityesoglu, said, 'Previously, quite apart from the fact we always had to undergo secondary processing, we had to send large items to a third party for cutting.

Now we can cut everything on our own water jet profiler.' * Divided table - the divided cutting table installed at CAN offers several advantages compared with the more usual interchangeable types.

Not only is the overall footprint smaller than a machine with interchangeable cutting tables, but the waterjet solution is also more economical.

While cutting is still being carried out on one side, the other side can be cleared or set up.

Another advantage of the machine is its high total load capacity of 18 tonnes.

That is, nine tonnes on each half of the cutting table.

With its new WJS NC-3060D machine, CAN can now with ease cut heavyweight refined steel and C-steel components such as wiper blades installed on the rotors of sludge driers, rings for flanges and base plates for traverses and seals.

More unusual orders can now be taken for such items as parts for coolant return systems for nuclear power stations.

The cutting of plated and laminated sheets has been noticeably simplified in comparison with plasma cutting where there was always the danger of the refined steel coming away from the base substance.

The new machine not only needed to be compact and cut precisely, but also allow for the handling of large pieces of typical rough sheet as large as 3m wide by 6m long.

CAN made their final choice only after considering other machines from both Germany and Switzerland.

Said Mityesoglu, 'The final decision in favour of WJS came down to the higher quality of the cuts achieved during tests.' * Service and support - most WJS customers invest in a complete system, including controls and pumps etc The value of having one single point of contact should not be underestimated.

Potential users who are not sure whether waterjet cutting is a logical investment for them, either as an alternative process or as a supplement, can try before they buy.

The Water Jet service centre in Weinstrasse, Neustadt, Germany, for example, can be used for contract cutting initially, as can the same facility at the parent company in Sweden.

* Consumer durables - WJS is justifiably proud of its reputation for incorporating only high quality components that retain their precision and efficiency over long periods of hard usage.

Some users, however, have been found to put these high levels of performance, accuracy and reliability at risk by the purchase of key consumables from sources other than the original manufacturers.

The use of cheaper (and therefore usually inferior) garnets and nozzle inserts for example, not only have been the cause of marked performance deterioration but also can lead to the original supplier's warranty on key components, such as pumps, being invalidated.