Improving competitiveness by ­strengthening in-house mould-making

“Quality in quantity”

Grote + Brocksieper GmbH + Co. KG in Kierspe in the ­Sauerland, a manufacturer of numerous plastic parts for a variety of industrial ­sectors, has ­e­xtended its machine park by adding a MV2400R ­precision ­wire-cutting ­machine. With its ­innovative technology, this EDM system is ­helping to optimise processes in the company significantly in the company. Along with boosting productivity, one of the company’s stated aims was to meet the growing requirements in terms of complexity, precision, quality and ­flexibility in the long term.

In mid-2016, Grote + Brocksieper GmbH + Co. KG, now under ­3rd-generation management, ­decided to purchase an innovative MV2400R wire-cutting machine from Mitsubishi Electric. This decision was taken so that it could cope with the growing volume of orders and meet customers’ rising expectations of precision and quality. This is not a replacement machine, as one might perhaps at first expect. In fact, the innovative wire-cutting system has been added to the machine park to absorb extra demand. The machine park in the company’s own tool-making department has so far consisted of several ­drilling and milling machines and die-sinking systems in addition to an FX10-K wire EDM from Mitsubishi Electric, which has been in operation since 1999. “The experience that we have gathered with the FX10-K in terms of quality, precision and ­dependability has been excellent. On the rare occasions that have we resorted to the hotline, we have ­always received professional support from Mitsubishi Electric’s experts. These were among the decisive factors that led us to choose the MV2400R when we were looking for a new EDM system,” explains Jörg Becker, Managing Partner of Grote + Brocksieper. “On top of this, the new machine generation offers a number of exciting technological and economic features which are essential in view of the over a ­million plastics parts that we output per day.” The company founded in 1939 ­today operates with an 85-strong ­workforce at its Grünenbaum and Bollwerk locations in Kierspe. Grote + Brocksieper generates about 90 per cent of its sales with plastic parts. Owing to the complexity of the items, just-in-time delivery, and the availability of injection moulding machines and their workload, the company’s own toolshop plays a prominent role in everyday operations. This is because the moulds it produces are absolutely ­essential for successful ­production. In addition to ­developing and ­fabricating new moulds for incoming jobs, it also routinely repairs and replaces wear parts. In the automotive ­sector, plastics parts can be expected to have a life cycle of 7 years. After this, the associated moulds are kept in good working order as replacement parts. There are even fields of applications in which resort is made to basic assemblies that have been around for some 40 years – but this is the absolute exception.

Customers benefit from receiving everything from a single source. This extends from technical consultations coupled with a test of feasibility, mould design and ­production, and initial sampling through to the finished product. On request, the company also handles such downstream tasks as finishing and module production. “The standards demanded of function, precision and quality have been rising year after year. A typical example of this trend is the desire for moulds with even more cavities. Some time back, we started with 8-cavity moulds, and are now achieving an ­astonishing 96. This way, much increased output is achieved in shorter production times. To keep pace with such trends, the tool steels used in the production of high-grade injection moulds have to undergo high-­precision machining. For this, ­accuracies in the µm range have to be possible,” Dipl.-Ing. Klaus Fischer, Technical Manager and Authorised Officer of Grote + Brocksieper, explains.

The new wire-cutting machine is in line with the latest state of the art and is equal to the growing demands. In particular, it masters the ­production of the required moulds with high precision, functionality and flexibility in terms of surface finish, parallelism, ­contours and tapers. Necessary for this are the associated machine performance, sufficient operating comfort and exceptional reliability. In addition, service and support from the ­manufacturer are growing in importance. Furthermore, the injection moulds are expected to boost process security, so that downtime in parts ­production is reduced to a minimum.

Demand for the innovative ­machine properties of the MV2400R
“In making our investment ­decision, we built on our positive ­experience with Mitsubishi Electric. We were additionally highly impressed by the performance of the wire-cut EDM system during the demonstration in Ratingen. The dependability, ­accuracy and machining speed of the MV2400R, for example, are vastly superior to those of the FX10-K. One of the main differences is that the new wire threader is highly dependable and supports totally unmanned operation,” says Jörg Becker. He then goes on to list the other factors that are ­relevant to the company:

• Large work space
• New automatic wire threader
• Comfortable operation
• ­Advanced drive strategy ­with   cogging suppression
• Remote monitoring of the ­ machine
• About 20 per cent lower ­energy consumption

The MV2400R was installed in November 2016 and was ­effortlessly integrated on the plug-and-play principle into the industrial process chain in a matter of days. During the installation of the MV2400R, a start-hole drilling ­machine from Mitsubishi Electric was also supplied. This drilling system is the perfect complement to the wire-cut EDM as it is designed to guide the operator quickly and easily from the starting point. It is capable of drilling not only small start holes of 0.3 to 3.0 mm in size, but also so-called functional holes.

The new wire-cut EDM offers comfortable intuitive operation with the input masks and symbols of the Natural User Interface. Workpiece set-up is supported with 3D views on the 15ʺ touchscreen at the machine. By measuring the workpiece surface with a measuring probe, the wire’s angle of inclination can be automatically compensated for and adapted to the precise workpiece position. Malfunctions are reported directly on-screen. With the aid of an extra window, the operator receives a problem analysis and instructions on the action to the taken. In the case of complicated ­applications, he can also follow all the machining steps in 3D on the monitor. The work area of the MV2400R permits the machining of mould plates measuring roughly 700 x 900 mm and weighing over 300 kg (up to 1.5 t maximum). There are also several options in terms of the number and characteristics of the cavities.

The quality of the finished parts is boosted significantly by the innovative Tubular Shaft Motor drive concept. The linear technology employed ensures adapted and totally cogging-free movements of the shafts by means of Tubular Shaft Motor. The responsive control behaviour thus achieved yields precisely controllable movements and positioning. This results among other things in precise wire guidance with clean cuts.

The automatic wire threader has had a lasting ­impact on work ­efficiency

“We’re delighted by the new Intelligent AT automatic wire threader. Whether after wire breakage, in the dielectric, in the kerf or in a continuous start hole, wire threading is performed absolutely reliably, quickly and with high precision. Consequently, downtime of the EDM system due to wire breakage, for instance, is now a thing of the past. It was therefore an obvious idea to make the fullest possible use of our wire-cutting machines, so workpieces that can be machined overnight on the MV2400R are now set up in the afternoon or evening,” Fischer explains. So that Grote + Brocksieper is nevertheless constantly aware of progress at night, weekends or on public holidays, it has purchased the optional mcAnywhere Control function. This remote access option comprises the convenient monitoring of critical machining processes via iPad or laptop and the consultation of a Mitsubishi Electric technician for assistance.

“Our expectations of performance and robustness of the MV2400R wire-cut EDM have been fully satisfied. The machine is capable of operating unmanned and we have achieved an appreciable boost to productivity. With energy efficiency and savings of material in terms of cutting wire, ion exchange resin and filter cartridges, this helps to cut operating costs,” says Becker summing up. “Our production expertise meets with high acceptance among our customers and strengthens our competitive position. We can view the future with confidence.”

Profile of Grote + Brocksieper

Grote + Brocksieper domiciled in Kierspe produces roughly a million plastic parts each day. These are precision and functional parts weighing anything from 0.03 to 600 grams, which often have high-gloss decorative surfaces and grains. For the production of such parts, which can consist of up to three plastic components as well as metal-plastic composites, 45 injection moulding machines are used. A variety of thermoplastics, ranging from standard to high-tech plastics, are processed. Its customers come from the automotive, aerosol and pump industries, the ­domestic appliance industry, medical technology, the electrical and electronic industry, and building construction. Such big names as Audi, Bentley, BMW, Mercedes, VW, Rolls Royce and Hella are among them.

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