The micromachined components produced by Germany-based Heraeus Medical Components meet exceptionally high standards in terms of accuracy, precision and surface finish. This excellence in micromachining is achieved thanks in no small part to 40 Swiss-type lathes from Tornos, and it has been bolstered by a recently introduced comprehensive digitisation strategy.
A brief history
The Heraeus Technology Group, headquartered in Hanau, Germany, is an international, family-owned company. Its roots go back to a pharmacy known as the Einhorn Apothecary, founded by the Heraeus family in 1660. Wilhelm Carl Heraeus (Heraeus), a pharmacist and chemist, took over the running of the Einhorn Apothecary from his father in 1851 and laid the foundations for a global, multifaceted business. In 1856, he developed an oxyhydrogen blowpipe and used it to melt large volumes of platinum to produce pure platinum. Until then, it had only been possible to use oxyhydrogen to melt small amounts of platinum in a laboratory. This pioneering achievement enabled Heraeus to found the W.C. Heraeus First German Platinum Smelters, which supplied pure platinum to goldsmith workshops and jewellery factories all over the world as well as a number of other markets.
Today, under the umbrella of Heraeus Holding, the Heraeus Technology Group comprises global business units (GBUs) that are market-oriented and functionally structured. One of these GBUs is Heraeus Medical Components, a specialist in metallurgical solutions for the design of highly demanding medical components. Heraeus Medical Components primarily manufactures components for cardiac rhythm management, neuromodulation and electrophysiology. To be able to reach the corresponding areas in the human body, however, the components and devices must be increasingly miniaturised. For Heraeus Medical Components, micromachining is more than just the manufacture of small and miniature components, it is about increasing skills and performance. Based on this approach, the company has earned a global reputation for its knowledge of and expertise in precious metals and alloys, materials science, micromachining and micromanufacturing.
The Heraeus Technology Group is headquartered in Hanau, Germany.
Turning excellence
Heraeus Medical Components’ turning shop is the origin of almost all components. The company uses its 40 Tornos Swiss-type lathes for all its turning tasks. About 250 different components are manufactured on these machines, in batch sizes of up to 4,500.
Many of the components are barely visible to the naked eye. This is the reason why many of the machines are equipped with special vacuum-operated discharge systems that deposit the components on a fleece. There are some high-sensitivity components that require a diameter of 1 mm and a length of 2 mm. These components are made of a platinum-iridium alloy and feature 0.01 mm holes and milled grooves and slots. At this size point, the Tornos SwissNano machines and their operators are reaching their limits. As these components are for the medical industry, absolute quality, non-existence of burrs, excellent surface finishes and traceability are mandatory.
Heraeus Medical Components lathe operators praise Tornos machines’ high precision, long life, flexibility, which is attributable to a counter-spindle, ease of access and ease of use. The last two factors are especially important in view of the materials used. Heraeus Medical Components relies on systematic precious metal tracking, and material is measured down to the gram for billing on every job. Certain tolerance thresholds must be maintained here and for this reason, the machines are meticulously cleaned after every job.
Heraeus Medical Components produces high-sensitivity components that are barely visible to the naked eye.
Process optimisation based on digitisation
Heraeus Medical Components is successful because of its steadfast commitment to continuous evolution. In mid-2019, the GBU tasked Lars Schubert, its lean manager for digital projects, with making its analogue machines digitally visible. The objectives of this were to analyse manufacturing processes, reveal productivity reserves, shorten procedures, incorporate quality management and documentation into the manufacturing process, and thus establish a better basis for decision making.
Initially, this seemed an insurmountable task, but Schubert sought the expertise of the Heraeus Digital Hub and together they decided to opt for a pragmatic approach involving small steps that did not lose sight of the big picture. In planning these steps, they considered the following questions: what information do we need, from whom do we get such information and how can we benefit from it?
As a first step, the Heraeus Digital Hub collaborated with Tornos to upgrade four pilot machines with the Tisis communication and programming software connectivity pack and thus enable production tracking.
Jörg Hempel, production line manager (left), and Lars Schubert, lean manager for digital projects (right), keep abreast of machine availability, production times, downtimes, etc. via Heraeus Medical Components’ visualisation program.
Tisis
Tisis software ensures appropriate tool selection, having a database that contains all the tool carrier systems, from simple turning tool holder plates to milling and polygon cutters and thread whirling cutters, for each machine. Each of these tool carrier systems has its own features and these are considered by the software.
Tisis provides intuitive user guidance through operation of the machine. Each tool carrier system has its own picture to allow for easy identification, and incompatibilities between tool carrier systems are detected. When a tool carrier system is selected, only the positions where it can be fitted on the machine are enabled. Furthermore, when a tool is selected, its default geometries are displayed.
In addition to actual programming, it is also possible to electronically transfer programs from the office PC to the machine. These programs can then be modified on the machine and transferred back to the office PC. Full traceability is maintained during both transfer operations.
At the start of the project, Heraeus Medical Components especially appreciated the monitoring function. This allowed for detailed monitoring of the machine inventory, which not only involved the status of the machines in the workshop but also the running of production. The latter included the workpiece counter, the remaining production time as well as the workpiece name and drawing, which could all be retrieved at any time.
Step by step towards better transparency
The pilot machines delivered all the required information in terms of their availability and production times and downtimes. Heraeus Medical Components created its own visualisation program and provided all departments involved with dashboards so that they could visualise the results. Once the stable running of this pilot test had been guaranteed, it was extended to almost all the Tornos machines, which saw a remarkable increase in efficiency.
It was extremely important for the managers to get everybody involved in a timely manner, since a project such as this can only work if appropriate leadership is guaranteed. All employees needed to be involved from an early stage, so it was made clear that management’s role was to provide support rather than keep tabs. This meant the project was very well accepted and as a second step, the reasons for downtimes could be analysed.
For this purpose, a suitable catalogue containing eight criteria was compiled in collaboration with the employees. Appropriate quick response (QR) codes were assigned to the criteria and these codes were attached to the machines or near the machines. In the case of machine downtime, the employee responsible for the machine simply scans the QR code and everybody else is informed in real time about the downtime, the reason for it and its duration. On this basis, any remaining analysis tools can be subsequently implemented, and the appropriate data are aggregated and made transparent. Furthermore, large computer monitors are installed in each department and the results are discussed at regular intervals during the ‘team dialogue’. Problems with machine components and tools can thus be jointly determined and solved relatively quickly. All these measures have brought about a significant increase in productivity and are exemplary for the whole company.
Last year, the project was nominated for the global intra-group Heraeus Award and made it to the final round. This has served to further motivate Lars Schubert and his team to schedule the next project steps. All electrical discharge machining (EDM) machines will be incorporated into the new system. At the same time, quality parameters will be incorporated gradually with process documentation, and these will then also be incorporated into the new system.
With its digitisation strategy, Heraeus Medical Components has demonstrated that continuous evolution pays off in a high-wage country such as Germany and helped towards ensuring guaranteed growth of the Group. Tornos is proud to have contributed to this success with appropriate machines and software.
Heraeus Medical Components produces high-precision, platinum-iridium alloy cable adapters with a high-quality surface finish and without burrs, in batch sizes of up to 4,500.
Heraeus Medical Componentshttps://bit.ly/3kkBlWY
Tornoswww.tornos.com/en