Case Study Switch to graphite sparks more changes at in-house mould shop

Editor: Eric Culp

A German manufacturer of components for the electronics industry found that a change-over from copper to graphite electrodes also rearranged the process for mould production.

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In 2008, the tool production department at Escha switched completely to graphite electrodes.
In 2008, the tool production department at Escha switched completely to graphite electrodes.
(Source: OPS-Ingersoll)

Due to extremely demanding precision requirements, the mould making operation at electronics components producer Escha Bauelemente GmbH has been completely rebuilt, has been outfitted with air conditioning, and the plant has been fully modernised. However, for sink erosion and HSC milling, OPS-Ingersoll remains the partner of choice in the tool construction. In addition, the concept of the supplier’s original Mold Center was modified. And it has been successful because machine operating times have again drastically increased.

Automation lowers costs

The basic idea was to economically design the electrode and mould production via HSC (high-speed cutting) milling and sink erosion with an automatic process. OPS was said to have achieved this in 2005 with the Mold Center.

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Three years later, Escha invested in this concept and at the same time switched from copper to graphite electrodes. The combination of the Gantry Eagle 400 sink erosion machine and the Speed Hawk 550 HSC milling machine seemed to be the perfect solution for the continually growing volume of orders. Particularly since the company could get everything from once source, i.e., milling, erosion, automation and job management. The management at the moulder selected the Multi-Change Performance with 154 electrode trays and 10 tool positions. Just four weeks after the initial operation, employees reportedly expressed their desire for another extension.

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For Jürgen Sikora, manager of materials, however, this was the lesser problem. “In 2008, when we invested in the plant, we also completely switched from copper to graphite electrodes.” He noted that although the company’s expectations were high, it found the low electrode wear and the the short time it took to file off the components in the milling and erosion processes surprising.

The Speed Hawk was mainly meant to produce graphite electrodes and also occasionally hard-mill them. Despite these two areas, the machine was too fast. This means that on the Gantry Eagle 400 – which was already working with Eagle technology – erosion took place around the clock and the milling machine was still not running at full capacity. “So we had the idea to fire two erosion machines with the Speed Hawk,” Sikora explained. The fact that the company often produces small electrodes – which generally equates to very short erosion times – gave rise to the idea.