At the Austrian company Wittmann Battenfeld, everything revolves around plastics. The company has a modern, diverse and modular range of machines for processing plastics and other plasticizable materials, including the M30 Millturn from WFL Millturn Technologies, which has recently become the focus of manufacturing high-precision rotating machine components.
In addition, the company’s state-of-the-art injection molding technology is used to manufacture high-tech products for industrial and medical applications as well as everyday objects.
The company, with its US office in Torrington, Connecticut, consists of two main divisions: Wittmann Battenfeld and Wittmann. Over 2200 employees worldwide work for the Wittmann Group, which is active in industries such as automotive, medical technology and packaging. The Wittmann Group employs over 450 people at its Kottingbrunn location and is one of the world’s leading manufacturers of injection molding machines, robots and peripheral devices for the plastics processing industry.
Wittmann Battenfeld offers a range of servohydraulic or electrical machines that can be designed horizontally or vertically, depending on customer requirements. Wittmann’s product range includes robots and automation systems, material supply systems, dryers, gravimetric and volumetric dosing devices, granulators as well as temperature control and cooling devices. The two business areas complement each other and customers benefit from a complete solution from a single source.
“We introduced the principle of complete machining into the company back in 1993, starting with the purchase of an M70 Millturn. In 1995 an M50 Millturn was added. Before that, we had a multi-stage production process, i.e. turning and milling on several machines, “says Martin Gorzolla, Production Manager at Wittmann Battenfeld. Even then, all turning, drilling and milling operations were combined in one machine. The complete machining concept makes production more efficient , avoids waiting times and ensures flexibility. The general aim is to shorten throughput times.
“Above all, however, excellent accuracy was one of the most important requirements for the machine,” says Gorzolla. In the following years an M60, an M65 and an M40 Millturn were added. The two older models M70 (1993) and M50 (1995) were replaced by the new M30 Millturn in 2020. In addition to maintaining the high level of accuracy, the price-performance ratio and the machine reliability, which are ultimately met by the WFL machine, were decisive for the purchase.
“Another decisive factor was the proximity to the WFL,” explains Martin Gorzolla. “The service department is very quick, the WFL team can be here in just 2 hours. In addition, the WFL service team has always been excellent in terms of speed and reliability. That is a big plus. We have been very satisfied with the machines over the years so we didn’t even think about switching to another provider, “adds Gorzolla.
The Millturn part program
The Millturn machines can completely machine the range of parts from screw tips, plasticizing units, captive C-disks, hollow shafts to struts and many other workpieces.
“We use these machines for everything that has to be ultra-precise. We usually only need one of each component that we produce for our injection molding machines. Our products are highly individualized, so we do not have large batch sizes. Everything has to be ready just-in-time, “says Christian Grafl, Head of Maintenance.
Not only are the production and assembly departments adjusted to this, but also the programming is very individual, says Grafl. The programmers are masters at this. With the EXAPT Plus programming system, you can take over the CAD data and create and simulate the program quickly and reliably. Thanks to the perfectly optimized post processor, the programs are automatically converted into machine-readable programs and sent via the internal network to a PC right next to the respective machine. The machine operator calls up the orders, loads the program into the NC control of the machine and orders – if not already available in the magazine – the required tools from the warehouse via the internal tool management. Workpieces with diameters from 85 mm to lengths of 4200 mm are currently being manufactured on the various MILLTURN machines.
“This enabled us to reduce processing times by around 20%. A real advantage when it comes to highly efficient production, ”says Gorzolla.
The new member of the ‘Millturn’ team
In 2020 the M30 Millturn was procured to replace the M50 and M70. With a milling power of 20 kW, it is able to efficiently machine workpieces up to a maximum diameter of 520 mm and a maximum machining length of up to 2,000 mm. Currently, the different workpieces are mainly manufactured in batch size 1 on the Millturn.
The machine model can perform machining tasks at 4000 or 9000 rpm on the main drive and the turning-drilling-milling unit. The turning-drilling-milling unit with its strong gear spindle with backlash-free B-axis also enables the use of large drills and milling cutters and thus high feed rates with great cutting depth. Stability is essential – thanks to the massive inclined bed made of gray cast iron and the WFL-typical axis arrangement, which directs the main cutting forces vertically into the bed. Particularly large guide spacing, large guides and minimal distances between the machining point and guides ensure stable behavior with difficult cuts as well as thermal stability for high-precision machining. Optimal chip flow is guaranteed by the fixed, absolutely smooth guide plate on the lower slide. Thanks to the high-precision, stable B-axis with a direct measuring system and additional mechanical indexing by means of the Hirth coupling, tight tolerances are achieved in all angles.
Wittmann Battenfeld usually uses machines with a tailstock. A stable bezel slide with an automatic self-centering bezel is also built in. This configuration offers a high degree of flexibility and enables a wide variety of workpieces to be machined with little retooling.
A disk magazine with 40 places ensures that there is a sufficient supply of tools on the machine. Wittmann Battenfeld has opted for a Capto C6 tool system for the M30 Millturn. It is characterized by a selection of boring bars with C6 coupling as well as excellent stability and precision. Tools up to 450 mm in length can be used in the machine. Magazine capacity and tool length could have been greater, but this was not necessary.
An 80 bar coolant pump is used specifically for a variety of internal machining operations. The standard version of the milling spindle enables not only a high pressure of up to 150 bar, but also an extremely high flow of coolant through the spindle. According to the company, this leads to a noticeable improvement in chip breakage, chip removal and process reliability in all drilling operations. In addition, WFL has a reliable coolant interface for the tool as well as suitable hardware components such as high-pressure coolant pumps, microfilters and additional cooling devices.
The increasing use of high-strength materials requires technologies that can also process these “super” materials reliably. In addition to the enormous time savings, there is an improvement in process reliability and surface quality as well as controlled chip evacuation. Unwanted heating of the workpiece is reduced to a minimum.
Eyes on the future
Wittmann Battenfeld aims to increase its world market share in standard machines. This of course includes a very focused and long-term product and sales strategy. “The most important thing is to keep the manufacturing and manufacturing know-how for critical parts in-house and to develop the necessary manufacturing know-how to increase efficiency and optimization,” says Marc Zachmann, Head of Production.
“We have already connected the operating technology (OT) to our ERP system and will continue on this path.” The main reason for connecting this technology is to increase production efficiency, for example through the automatic generation of technical parts lists during autonomous order processing in fully automatic welding systems as well as production feedback from production units to our ERP system, “says Zachmann.
Wittmann Battenfeld offers its own Industry 4.0 solution for the products; Complete injection molding work cells, consisting of injection molding machine, automation and peripheral devices. This solution enables the formation of production units through several intelligently connected components that work in a work cell. This allows the individual components to communicate with each other via OPC UA, share settings and states and even perform self-optimization. With this unique mix of innovative products and efficient production, Wittmann Battenfeld is ideally equipped for the future.