Magnetfabrik Bonn, one of the leading magnet producers in Germany, always opt for safety first when it comes to quality. For more than two decades, they have been using HASCO filters. They have now tested the new model H5055/… in practice, with a positive result and the expectation of extra added value for the customer. The complete production in Bonn is now being successively switched to this latest innovation from HASCO.
Driving onto the site of the magnet factory in the middle of Bonn, visitors can admire a historical brick facade that reflects the German industry culture. The family company, with around 120 employees, has been an important supplier to German high-tech companies since 1932. On entering the production area, at the heart of the building complex, it immediately becomes clear why the 78 million magnets that are produced there every year are described as high-tech, even though, at first glance, they come across as rather unimposing. They are used wherever measurements are made or controls are carried out. In a modern car, for example, at least 600 of these products are installed for this purpose. Through “field shaping” – the very precise design of electromagnetic fields – every product is customised. The know-how of the magnet factory is also completed by the very sensitive aspect of material selection and the design of demanding geometries.
“The product responsibility for the design lies with our customers. In Bonn, there is no product development taking place in the traditional sense. Our know-how lies exclusively in the customer-specific development and design of the articles, that is something we do particularly well,” says sales manager, Frank Burilov. “We are service partners and service providers for our customers.”
“Quality is therefore of paramount importance to us,” says Marcus Mohr, head of the toolmaking division at Magnetfabrik Bonn. The products are produced almost exclusively by the fully automatic injection moulding process. More than 500 moulds with a general size of 600 x 600 mm are used. The base material is polyamide, as the binding mass, which is processed either as virgin material or as recyclate/millbase. Hard ferrites and rare earths are used as fillers, with the addition of defined additives that are selected for their desired magnetic and mechanical requirements. Flow properties of the magnet materials in the mould must be adequately simulated and, last of all, must not influence the necessary quality of the finished product. They have used the H109/… filters, where possible, for many years, installing them on the nozzle side. These hole filters assume the important task of removing all foreign substances from the material compound. “That can theoretically be anything that is relevant in an injection moulding process: From a broken screw, a splinter from the mill from the grinding process of the recyclate or from the material of the outer packaging of the compound.”
Innovative hole filter H5055/… with new features
With its follow-up model H5055/…, HASCO offers a hole filter made from stainless steel, which differs from its predecessor through its innovative design. More than 1,000 angled holes provide an optimum melt flow and reduce shear and flow velocity. In a market comparison, H5055/… guarantees the lowest pressure loss with the same filter performance. The filter can be used in the machine nozzle and in the sprue bushing. Apart from that, Stefan Reich / Key Account Engineer and Jörg Karthaus / Technical Salesman at HASCO, emphasise that the service life through the use of a corrosion-resistant material is much longer and cleaning is very much easier for the user.
Injection pressures fell by 20 percent
That is something that Marcus Mohr can confirm, because the new model has already been tested in-house over several months. The results, after the initial scepticism had disappeared, showed a positive effect in several aspects of the process and the part quality. “When Stefan Reich introduced us to the product at the beginning, I simply couldn’t believe it,” says the Technical Manager recalling, very precisely, the start of the practical tests. The service life of a filter is, for him, oriented to the tonnages of material that are processed with the injection moulding machine. When the filter was dismantled after the comparable number of operating hours, he was pleasantly surprised that it was still in very good condition. “We could hardly believe our eyes, because really the filter should no longer exist or have been completely worn out.” Stefan Reich, praised at this point, his customer for the openness in also trying out new things. “In Germany, it is certainly something that can no longer be taken for granted,” says the Key Account Executive, speaking from his many years of experience.
Yet, Marcus Mohr can supply even more facts which, he says himself, he had not expected. “The injection pressures alone fell by 20 percent. This naturally has a positive effect on our component quality.” Jörg Karthaus: “The effect is backed by the completely new geometry of our hole filter.” Compared with the predecessor, it has a significantly larger number of holes in the surface and thus enables much higher filter throughput. Through the differentiated arrangement, the shear is recognisably lower and the injection pressures get more easily into the mould fitted with a hot runner
system.
Marcus Mohr also makes a positive appraisal of the direction of installation of the filter: “First of all, we had a look to see from which direction the filter is installed. On dismantling, the contamination settles in the outer area, as a result of which we can subsequently clean the filter much better.” Moulding tools that are built exclusively in-house are re-equipped every day. To do this, use is made among other thins of HASCO’s quick-action couplings. We have hardly any mono-cultures in production, says Marcus Mohr. A partnership relationship has existed with HASCO for decades. Marcus Mohr can well remember that the Tempflex system had been jointly developed for their own cooling purposes.
Filter insert H5055/… a must for every customer
“I would recommend every injection moulder use these hole filters,” said Marcus Mohr, immediately providing an explanation: For one of his customers, he had in the past taken the trouble to note down all the possibilities of contamination. “The customer had not been aware of the extent to which the contamination could get into the melt and finally find its way into the product.” To prevent this in the conventional way is very complicated and, at the same time, almost impossible. For this reason, the use of the hole filter H5055/… for the magnet factory has now become a must and is recommended for general use by all injection moulders – even with virgin material. “We always work with a healthy human understanding,” says Frank Burilov. “Everything that improves the quality of our products is utilised. It is nevertheless clear that wherever people work, errors occur.” “From the customer’s point of view, one of the downsides, in the past, was the reultant pressure loss,” says Stefan Reich, recalling a number of customer discussions. “At this point, I can put everyone’s mind at rest and encourage them to take the tip from Marcus Mohr – simply test the product, run empty injection pressures and to learn appreciate the advantages.”
Positive outcome: More stable processes and higher quality
Marcus Mohr and Frank Burilov both draw a positive conclusion: The changeover to the new hole filter H5055/… is now being carried out in stages. This can take up to three years with the large product variety of Magnetfabrik Bonn. “HASCO is helping us, through the innovation and further development of the standard mould units and hot runner components, in making our processes more stable and increasing the quality of our products. In this way, they enable us to serve our customers better and, in this respect, make a good impression,” says Frank Burilov, with a clear acknowledgement of the cooperation with HASCO.
HASCO Hasenclever GmbH + Co KG
As a leading manufacturer of standardised, modular quality standard mould units and individually designed hot runner systems, HASCO offers innovative and economical solutions for designers, mouldmakers and injection moulders from a single source. More than 700 employees at 35 sites worldwide enable moulds to be built in the simplest possible way.
More information: www.hasco.com/en
