EDM High precision leads to new fields of economical applications
In 2018, the mould making department at Procter & Gamble optimised its portfolio in order to meet the requirements of multicavity moulds requiring small high accuracy geometries. In addition, the company wanted to consistently continue the changeover from copper to graphite electrodes, which began in 2014. With the investment in OPS-Ingersoll’s Eagle G5 Precision die-sinking EDM machine, they have fulfilled this task.
Prototyping and toolmaking activities at Procter & Gamble, are focused on dry and wet shavers as well as manual and electronic toothbrushes. To meet the high interchangeability and accuracy demands, the Kronberg plant was therefore looking for a new die-sinking EDM machine in 2018. After some research, the company invested in the Eagle G5 Precision from OPS-Ingersoll. Jürgen Mohr, Group Head of Innovative Prototype and Molding Technologies (iPMT), sees this decision as an investment in the future: “In the course of merging the areas of prototyping and mould making, we wanted to uplift our portfolio. After a short benchmark, we realised that there was no machine on the market that was really comparable. On the other hand, we have found that the quality characteristics of the G5 Precision enabled us to meet our requirements for high precision in multicavity moulds and high-quality surfaces.”
Components that are extremely demanding and in terms of sizes, e.g. cleaning elements of a toothbrush, sometimes as small as a grain of plastic granulate. The applications clearly indicate how necessary the investment in this high-tech machine had been. These include 3-component injection moulded parts in 128-cavity moulds, with tolerances of 5 µm in many cases. With its high-quality equipment, innovative automation solutions and new strategies, prototyping and mould construction at P&G has been regarded as exemplary in the industry for decades. This is another reason why the investment in automation, including the Eagle G5 Precision, appears to be ground-breaking, because it has also changed their manufacturing strategies. While these components used to be milled at high cost due to the small milling cutter diameters, the G5 Precision leads the path back to EDM.
Due to the process reliability and the fact that it is no longer necessary to intervene in the process in order to optimize the erosion technology, it is now possible to manufacture parts with an accuracy of less than +/- one hundreds of a millimetre in a fully automated process. There are enough examples in Kronberg that speak for the use of EDM. These are, for ex-ample, mould cores with a clamping length of ~250 mm that have a tendency to vibrate during milling. Whereas these used to be milled and partially eroded, they are now finished in a single EDM operation on the G5 Precision.
The total package creates new solutions
After investing in the G5 Precision, however, those responsible were faced with the question of whether to integrate the G5 Precision into the existing automation line or to use it as an automated stand-alone machine. Due to the fact that the company operates in the end-to-end arena, from prototype, pre-production to series moulds, the decision was made in favour of the stand-alone solution, this allowed for more flexibility with the handling system Multi Change offered from OPS-Ingersoll. In this context, however, the Job Management System that runs to the line-automation system also appears to be particularly interesting for the stand-alone automation. In a pilot project, OPS-Ingersoll and P&G have expanded the system to utilize EDM within the Job Management System.
Matthias Schmidt, Sales Manager at OPS-Ingersoll, comments: “This job manager connection is unique. Since the job management system provided by the manufacturer of the milling machines is designed for milling, i.e. it has a relatively simple structure and does not offer any specific functions that are required for erosion. Now it can call up where parts are currently located at any time, even if they are in a robot that is not part of their system in terms of software (e.g. measuring).” In addition to the job management, maximum precision and high-quality surfaces, the whole system creates more added value. P&G has now reached the point where they can offer solutions that were not previously feasible. Among other subjects, the achievable surfaces are absolutely new territory for those involved.
OPS-Ingersoll promises a quality of less than VDI 10 with the corresponding graphite grade. In Kronberg, VDI 10 is now reliably achieved in an automatic process. Even finer surfaces, e.g. VDI 1, are still realised with copper electrodes! The interchangeable frame of a shaver provides the proof of concept: The component was previously milled, eroded, polished and then decorated with a functional surface. Since this is a premium product, it was also intended to be provided with an electroplated surface. With the G5 Precision, however, it has been possible to achieve surface finishes of less than VDI 10 and to eliminate reworking. This is an enormously helpful advantage, when com-pared with external suppliers and the newly defined economic efficiency. The economic saving are achieved because reworking or additional finishing could be completely eliminated in some areas. Electrode wear has been noticeably reduced once again with the new multicavity technology provided by the technology programming system “Power Spark Editor”; Additionally, cycle times are again significantly shorter in some cases due to the new Eagle Power Spark generator. Furthermore, according to Jürgen Mohr, the work-load can be controlled much easier.
P&G, Focus set on innovative Prototype and Molding Technologies
Braun & Oral-B electrical appliances gained worldwide reputation for their distinctive design. The GIC (German Innovation Center) / Development Center for Devices is located at the Kronberg Taunus campus. The iPMT (innovative Prototyping & Molding Technologies) team with approx. 70 employees realizes the ideas and concepts from research & development. This area combines specialists from technologies and core competencies such as Additive Manufacturing, Modelling & Simulation, Process Development, Mold Development & Design, Mold Engineering and Prototyping & Manufacturing, who together stand as E2E development partners, from the prototype to the series tool. For the internally produced prototypes and components, a fully automated production line is available in the manufacturing area, on which prototypes, test moulds and moulding tool components for injection moulds as well as electrodes are produced and further processed.
Jürgen Mohr: “We've been working with the G5 Precision for quite some time, but I don't think we’ve reached the top of the development curve yet. We need to keep confirming results, getting faster and more economical. And we need to find new applications.”
Without motivated employees, such results are not possible. Viktor Hert, CNC and machine operator at iPMT, for example, grows with the processes. A component that was originally planned to be engraved by means of a laser, was produced by him on the G5 Precision.