Perforated metal is encountered in many areas. It can be found in industry and sound insulation as well as in air conditioning technology and food production, although perforated sheet can also be used to clad the façades of buildings. In all these areas, the products from Schäfer meet the toughest requirements in terms of quality and availability. For its punching tools, Schäfer relies on EDM technology from Mitsubishi Electric for its perforated sheet. The toolmakers at Schäfer are particularly proud of their FA30, which has been put to more than 100,000 hours of use since 2001 and is still producing top-quality punching tools.
Today, the Schäfer Werke Group can look back on over 80 years of experience of steel processing. More than 1,000 employees contribute to the company’s success at its state-of-the-art production sites in Germany and the Czech Republic. From its base in Neunkirchen in the Siegerland region, the family-owned company now operates worldwide through its numerous divisions. One of its focuses is on perforated sheet metal, and Schäfer satisfies its customers with a wide range of products. Its standard range comprises over 400 different perforation patterns in a variety of sizes and grades in a wide range of materials and in thicknesses from 0.5 to 3.0 millimetres. Other specialities include perforated sheets to customer specification and its machining service. Schäfer responds to customer’s wishes flexibly and efficiently at its modern production facilities.
For Daniel Sauer, Assistant Technical Manager, on-time delivery and quality are the decisive unique selling points of Schäfer Perforated Metal. “We are very quick to respond to and satisfy customer requests,” Sauer explains. “Quality management plays a central role here. For 25 years, all the critical stages in production have been integrated into the system.” The company produces around two million running metres of perforated sheet metal per year from all materials and with a variety of finishes.
Optimising the air flow of radiator grilles
One of the tasks of a radiator grill is to supply vehicle engines with the air they need and to protect them from mechanical impact. Together with its customers, Schäfer perforated sheet has developed among other things new approaches in the improvement of engine cooling. Originally, a diamond-shaped perforation was envisaged for a customer to protect the engine. In the designing process, the developers discovered the advantages of hexagonal perforations for this application and thus increased the air throughput significantly. This improvement in cooling performance has a measurable effect on engine cooling. The company has achieved similar improvements on agricultural vehicles.
Hexagonal perforations were a challenge for the toolmaking department, because with this hole pattern only 12 per cent of the sheet metal is retained. So that these sheets are highly air-permeable, up to 80 per cent of the material is punched out. The remaining percentage must then deliver the necessary rigidity.
State-of-the-art machinery in the toolmaking department
Since the company’s founding, the in-house toolshop has been responsible for making and maintaining all the tools. “In addition,” Sauer explains, “we also produce the spare parts for our machinery as far as possible. We have a variety of machining techniques here and expertise that has accumulated over the years. On top of all this, we work quickly and inexpensively.” For their activities the toolmakers have a state-of-the-art machine park at their disposal. In addition to the three EDM units from Mitsubishi Electric, there are a variety of lathes, milling machines and grinding benches.
The first Mitsubishi Electric FX20 was introduced back in 1997, to be replaced in 2001 by a larger FA30. “For 20 years it has been running on a daily basis to our complete satisfaction. The FA30 is the oldest machine in the toolshop,” Sauer reports. “Nevertheless, the machine still does its job one hundred per cent. This is due both to the FA30’s top quality and our skilled staff, which receives comprehensive training to handle the machines with the necessary care.”
Over 100,000 hours in operation
The performance of the Mitsubishi Electric FA30 is outstanding. In the past 20 years it has clocked up well over 100,000 operating hours. “We did a rough calculation of the number of threadings during this period,” Sauer explains, “and arrived at a figure of over a million – which absolutely stunned us. Since we are totally satisfied with the machine’s quality and reliability, we see no reason at the moment for us to replace it with a new one.”
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Caption: IT racks with doors of perforated sheet ensure efficient ventilation.
To boost its EDM capacity, the company installed a Mitsubishi Electric MV4800R Connect in August 2021. The tool guides mainly run on the large machines, the FA30 and the MV4800R Connect. To machine workpieces with a length of 1,650 millimetres and a width of 200 millimetres, the standard machines had to be slightly modified. Dies with a maximum length of 330 millimetres are usually cut by the toolmakers on a FA10s Advance. “Although the machining programs dictate to some extent which machines are used for which jobs,” Neuser adds, “it can still be safely said that the MV4800R Connect and the FA30 are used for the same tasks.”
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Caption: Generations apart – the new MV4800R (left) and the FA30 (right) being operated by employees M. Brock and M. Knautz.
All-important dependability
“For a direct comparison of the two machine generations,” says Sauer, “the new MV4800R Connect simply hasn’t been running long enough. After tests at Mitsubishi, we are assuming that the cutting speed of the new machine is not significantly faster. One point that immediately catches the eye, however, is its remarkable speed during wire threading. The process runs much faster as a result, and this makes itself felt in the machine’s overall productivity. It is hugely important for us that the wire threader operates trouble-free, because our EDM machines all run during an unmanned third shift.
While process reliability, therefore, is crucial for Schäfer Werke, the company can always depend on the machines from Mitsubishi Electric. “When we start the process in the evening, the jobs are either finished or still running in the morning,” Sauer concludes.
For More information, contact WD Hearn – Tel: 021 534 5351
