The demands of the pharmaceutical industry generally go beyond the norm when it comes to material, machining strategy and quality. This means that those who want to establish and prove themselves in this area must possess the necessary expertise and optimum technical equipment. An example is Herzog CNC Zerspanung, based in Anröchte, Germany, who can handle any machining challenge – thanks, in part, to our tools.
Founded in 2005 by Andreas Herzog as a contract manufacturing company grew rapidly, and the company moved into a newly constructed production facility in 2010.
One customer for whom Herzog manufactured an increasing amount of ever more challenging parts in recent years is L. B. Bohle Maschinen + Verfahren GmbH from Ennigerloh, about 50 kilometres away from them. The company specialises in handling and process machinery for the pharmaceutical industry.
Andreas’ son, Marcel, takes up the story: "In addition to the normal milled and turned parts we were already producing for them, L. B. Bohle wanted us to make a polished and eccentrically ground component. Therefore, we produced a couple of test parts – and the customer was thrilled right from the start!"
The part was by no means easy to produce, machined from a special kind of stainless steelwith a form that consistedof bars that were just 2 mm wide and 20 mm high, with small corner radii and tight corners which were barely possible to pass through. The clamping devices had to be selected with millimetre precision to offer the milling cutters a chatter-free hold, while gripping on the minimum of material.
“The finished component needs a total of three clamping operations. In the first operation the outside profile and the thread were milled ensuring that the material removed did not affect the stability of the component. After this, all the other sides were machined. The final clamping operation was to machine the grooves, with positional tolerances of 0.05 mm. Total cycle times were up to 12 hours, depending on the specific component" explains Marcel Herzog.
To improve machining processes trochoidal milling techniques were used. "Although it wouldn't have taken any longer with the 'old' milling techniques, I might have had to use ten times as many tools,” says Marcel Herzog. “Trochoidal, in contrast, is process-secure and the tool life is excellent. Best of all, it didn't need any intervention from me! I knew that roughing now took just under two hours leaving me free to take care of something else during this time.
The process was run on an Okuma Genos M560, which had proven to be a precise and reliable machine, among other things due to the tool breakage monitoring and automatic tool length measurement. And so, in terms of surface technology, a very good, deposit-free result was achieved even before polishing.
Such smoothness as achieved by the polishing process can hardly be reproduced on the machine, confirms Thomas Sicke, Technical Consulting & Sales\Cutting Tools at CERATIZIT and responsible for the Herzog company from the very beginning: "We know this from mould making, where we have smaller segments that really come off the machine as smooth as polished. We have special milling strategies for that, but they tend to be around 40 hours because of the small circuits." Manual polishing, on the other hand, takes 12 to 16 hours.
In its early days the company opted for very cheap tool solutions, but his strategy quickly changed:
The result is that everything is now from CERATIZIT's portfolio. Herzog's project with L. B. Bohle clearly shows that everything hinges upon durable and process-secure tools. This is not a gut feeling, but a fact backed up by numerous examples. "One tool that is used at Herzog is, in the truest sense of the word, outstanding: we received the Hans-Jürgen Warnecke Innovation Award from the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) for the S-Cut. Its special, S-shaped side profile reduces vibrations, resulting in a long tool life. Therefore, many of our customers use it for volume production, where it delivers a 50 to 60% longer tool life," says Thomas Sicke, Technical Sales Engineer, Ceratizit.
These S-Cut tools were used for rough machining the L. B. Bohle component. "During 3D roughing, it removed everything with ease with a full depth and 2.5 mm stepover. In terms of chip volumes, this was tremendous", said Marcel Herzog.
Initially Marcel Herzog decided to play it safe and stocked up on all the tools. "Five 12 mm, four 10 mm and six 8 mm milling cutters for precision work. I used two of each at most!" His father was suitably impressed: "My son showed me tools that had been used for a long time. They looked as if they had never been used!"
Also reducing cycle times at Herzog are CCR CircularLine milling cutters with their long cutting lengths and chip breakers delivering high chip volumes and shorter runtimes. "These cutters have saved us a huge amount of money. We needed to rough mill 12 mm of material, when using a competitor's tool, I had to index the inserts three times. Now I can do exactly the same thing with just one cutting edge!" says Marcel Herzog and Thomas Sicke right along with him. "I am always happy when our tools are used in a 'species-appropriate' way. After all, we develop our tools so that the customer becomes faster with them!"
To help manage tool useage Herzog CNC Zerspanung is using the Tool-O-Mat tool dispensing system, which has brought even greater flexibility: "Some specific tools are needed for a special order, which might only be requested once a year. To avoid running out of tools in case of damage, we have a Tool-O-Mat, from which I can simply draw the next tool. Once the stock falls below the minimum level, it is automatically replenished and I don't need to worry about it!"
As a consignment store, the Tool-O-Mat also frees up some capital in the company. Instead of placing tools into drawers at a cost of several thousand euros, the customer only takes and pays for the tools they actually require.
When it comes to after-sales service, Andreas and Marcel Herzog can completely count on their advisor Thomas Sicke. "When dealing with application technicians from other manufacturers, I often got the impression that it would be a long road to the desired result involving test runs, but with Mr Sicke it is completely the opposite. When I describe a task to him, he recommends a specific tool to me, tells me the possible cutting speeds, the feed and then it can get under way. Right off the bat, we have shortened our process times and thereby saved good money so many times."
Thomas Sicke also believes that this only works when you interact as equals: "Marcel Herzog understands exactly what I mean and implements it, because, for one thing, he has a feel for the machine in question. He knows what he is doing and so the recommended tool is able to deliver the best results!"
Reliability and stringent quality standards are not just the preserve of plant engineering for the pharmaceutical industry. Which is why Herzog has always believed in having everything documented and checked (by two people) from receipt of goods to goods dispatch – and this has paid off. "We even help customers carry out quality assurance to some extent. Over the years we have built up such a foundation of trust, as customers know that if it's from Herzog, it'll be flawless," adds Andreas Herzog.
By focussing on special machining tasks, Herzog CNC Zerspanung stand out from the crowd. Their success rests upon a careful selection of state-of-the-art machinery and a wide-ranging portfolio of tools. "And we must not forget our specialist personnel. We employ experienced machining specialists – and now we can even train them ourselves. Our first trainee just passed his exam with the mark 'very good'," notes Andreas Herzog proudly. There will never be a dull moment at Herzog – the requirements are usually far too unique for that. "This is also something that sets us apart from the rest: we make the parts that not everyone wants to make or is able to make. And when customers come back to us and say we should be proud of what we created, that motivates us to raise the bar that little bit further each time!" sums up Andreas Herzog.