V - The magazine of the VOLLMER Group - 2018

blade Vmax with mechanically replaceable blades. LENNARTZ develops circular saw blades for professional metal cutting and adapts them to specific manufacturing steps. Apart from precision, the focus lies on cutting speed and material saving in the in-house research and development. "Thanks to increasingly thinner circular saw blades ma- terial consumption can be lowered and costs reduced in the machining", says Frank Mich, Technical Director at LENNARTZ. "However, thin circular saw blades with diameters up to two and a half metres place extremely high demands on the stiff- ness of the material, so that the saw blade does not go astray and vibrate during the metal cut. We stabilise our blades using the cold deformation procedure." In order to also stay ahead in this area, the so-called tensioning, measuring and straightening of blades, in 2008 LENNARTZ took over the recognised and world-leading specialist Mummenhoff Technology. The company manufac- tures and sells all machines for the tensioning, straightening and measuring of circular saw blades of all sizes. LENNARTZ boosted this expertise from a technological perspective and has been continuing to do so for ten years now. SHARPENING WITH SWABIAN ACCURACY Thanks to the cold deformation with corresponding rolling operations LENNARTZ is able to compress and stiffen the steel of the circular saw blades. For instance, even circular saws with two and a half metre diameter cut various metals at high cutting speed. When it comes to the sharpening of saw teeth, the company has been relying on the expertise of VOLLMER for over 50 years now. There are around 40 machines of the Swabian sharpening specialist in the halls of LENNARTZ, which are used to machine the different geometries of the saw teeth – there are between 400 and 500. NO TWO CIRCULAR SAWS ARE THE SAME A look at the requirements of metal-cutting quickly shows why specific circular saw blades are essential: Ring-rolling mills cut, e.g. wheel tyres, conical gear wheels or gears, which are made from different materials. In the aerospace industry LENNARTZ circular saws have to saw temperature-resistant steels with nickel and chromium, which are extremely resistant. Companies from the auto- motive industry machine various components with circular saws, which range from the engine block to the wheel axle through to the headrest post. A customer often needs up to a dozen different saw blade versions for the manufacture of one product. "For us it is key that we work closely with our partners in order to realise very specific tasks", says Karl Arnd Lennartz. "This applies not only to our customers, but also to our sup- pliers. This is why we are often on board at VOLLMER when it comes to the development of sharpening machines for circular saw blades." WWW. LENNARTZ .DE VOLLMER IN ACTION! The Remscheid-based company LENNARTZ uses more than 40 VOLLMER machines for the manufacture and machining of its circular saw blades. The company mainly manufactures carbide-tipped circular saw blades, HSS cir- cular saw blades, as well as segmental circular saw blades, customised to the requirements of customers. LENNARTZ received the first VOLLMER sharpening machines in 1966. The VOLLMER CM, CHD and CHF sharpening machines are among their most recent acquisitions. These machine concepts can be used to sharpen carbide-tipped circular saw blades in a single and precise clamping operation. Combined with a ND handling system and appropriate loading carriage for automatic tipping, these machines are in operation around the clock. FRANK MICH, TECHNICAL DIRECTOR AT LENNARTZ, IN THE MIDDLE OF CIRCULAR SAW PRODUC- TION. 19 18 INSIGHTS