Citation
(2008), "Charles Day Steel invest in second Water Jet Sweden machine in space of 12 months", Aircraft Engineering and Aerospace Technology, Vol. 80 No. 6. https://doi.org/10.1108/aeat.2008.12780faf.010
Publisher
:Emerald Group Publishing Limited
Copyright © 2008, Emerald Group Publishing Limited
Charles Day Steel invest in second Water Jet Sweden machine in space of 12 months
Article Type: Feature From: Aircraft Engineering and Aerospace Technology: An International Journal, Volume 80, Issue 6
Already using the largest Water Jet Sweden (WJS) profiler in the UK, Sheffield-based Charles Day Steel, has opted for a second machine from the same manufacturer. Unique amongst British specialist subcontract profilers by being able to offer its customers the choice from all three profiling methods, flame, laser or water-jet, the company continues to grow its business by smart investment.
Material economy
Workpieces profiled on the WJS 4020 can be produced with such fine kerf widths and accuracies that, when combined with modern nesting techniques, really substantial material savings can be offered to customers.
One such recent example has been for pairs of rings to be cut from a large sheet of 30 mm thick stainless steel, whereby all that separated the two was a thin (2 mm) ring sliver of 710 mm diameter (Figure 1).
Another classic example of the flexibility of water jet operation is that of a 1 m diameter × 5 mm thick stainless steel distributor plate for the chemical industry, where a myriad array of 300+ holes down to as little as 3 or even 2 mm diameter had to be accurately placed (Figure 2).
The surface finish obtainable with the water jet process is free from burrs and is invariably sufficiently smooth as to require no subsequent machining and, of course, the material is left tension free.
With the addition of this second WJS machine, Charles Day expect water jet production will account for a full 15 per cent of the company’s throughput this year and give a significant boost to the business growth it has consistently experienced in recent years.
Speaking of this installation, Chris Baker, Managing Director, Water Jet Sweden (UK), said: “Charles Day is not the first UK customer to ‘ask WJS for more’ and I’m confident that others in the country will soon be following suit”.
Details available from: WJS UK Ltd, Tel: +44 (0)1937 845 499, Fax: +44 (0) 7092 860 980, E-mail: info@ waterjetsweden.com
More flexibility
The latest round of new plant purchases by the company has included, not only a fifth laser cutting machine, but also a second WJS water jet profiler to join the giant 8.5 × 4 m WJS machine installed a year earlier. Phil Wooffinden, Managing Director, says: “Whilst the large format machine has certainly helped outsmart competitors, it can, almost by definition, sometimes be tied up for long periods of time executing complex programs on large parts”.
For this reason a second, smaller water jet profiler was needed in order to satisfy customer confidence in providing a fast turn-around, especially in this age of short supplier chains and JIT demands.
A job analysis soon showed that, in terms of throughput, a smaller WJS machine would meet the requirements and so the standard mid-sized 4 × 2 m WJS 4020 ED model was selected and rapidly brought on-stream.
To cater for the company’s additional capacity, the company has had to spend an additional £100,000 on a new electrical sub-station so that all machines can be run and to “future-proof” its power requirements.
As was the case with its first WJS purchase, Phil Wooffinden made a detailed assessment of other water jet profilers on the market before making a firm decision. In this case, he admits, the ability to use the same software and consequent absence of a new learning curve for the operators, were positive factors in staying with the Swedish supplier. The reliability of the first WJS machine and good service provided since it was installed served also to reinforce the logic of this decision.
Additional accessories
Important other factors also contributed to making the overall water jet facility at Charles Day Steel into a highly flexible and efficient entity. Instead of simply supplying a single pump and single garnet storage hopper with the new profiler, WJS was contracted to install two of each and to provide a distribution system that such extra power can be provided where needed.
Thus, there are now three 50 HP KMT pumps available and so, whenever the new, smaller machine is in use, a sufficient volume of water at the fully-rated 60,000 psi can be supplied to each of the three heads of the larger machine, even if the “larger” 0.35 mm nozzles are in use, thereby significantly improve cutting speeds and productivity. An obvious advantage of having three individual water and abrasive (garnet) sources of supply is that, should any one of them require maintenance attention, production can continue apace.
Environmental improvement
Environmental considerations have also been addressed whereby a communal twin-weir ASAS de-sludging system has been installed, thereby allowing filtered water to be recycled to both profilers rather than flushed away into the drainage system.
The new 4 × 2 m capacity WJS profiler, like its larger stable companion, is equipped with four water/abrasive heads so that, not only can productivity be hiked by profiling two components simultaneously, but also switching from one method of cutting to the other is also both quick and easy.
Flexibility
Soft materials, including foam, plastics, gaskets and rubber for example, are easily profiled using water alone, while harder materials such as tooling steels of up to 300 mm thickness are profiled using the abrasive heads. Both of these processes, unlike laser and flame cutting, are totally free from creating any heat affected zones or distortion.
The two profilers have also the popular WJS automatic splashguard fitted that help avoid unwanted stray water from settling onto the operator’s work area or the swivel-mounted Fanuc 18EMi control system console.
Soft touch
The tiny orifices used (0.1-0.35 mm diameter) and through which water is ejected at speeds calculated to be up to 2.5 the speed of sound (800 m/s), are vital to the operation of a water jet machine. Apart from the garnet used when in abrasive cutting mode, the only other “consumables” that water jet machines require are the diamond or sapphire nozzle inserts. Some users in hard water areas will resort to the installation of water softeners to help prolong jet orifice life but, according to Phil Wooffinden: “Being in Sheffield, we have the advantage of enjoying famously soft water and so have no problems in this regard”.