Increased efficiency and reduced production costs are two recurring items on the agenda of most company managements. In recent years, outsourcing has become a more common solution, with many companies moving some or all of their production to low-wage countries.
But many chief executives have learnt the hard way that there are no simple solutions. They have found that outsourcing does not always bring the savings they were aiming for. More and more of them are bringing the jobs back home so that they can control and optimise the entire process within their own four walls.
This way of working - optimising creativity in your own refinement chain – is used at Wilden Werkzeug- und Automatisierungstechnik GmbH of Wackersdorf, Germany.
Manfred Baumann, CEO, explains: “We have supplied more than 6500 quality tools. We make use of this sound experience in close collaboration between functions such as product development, tool design, preparation, NC programming and production in our own workshops. The backbone of the operation is a combination of our highly-qualified employees and an interlinked flow of materials and data.”
An example of a recently-delivered job – a two-component injection moulding tool with dual cavities, for a garden shower. The customer, Gardena, is highly quality-conscious and demanded a VDI 27 surface finish, a maximum cycle time of 40 seconds, and a guaranteed life of one million shots per insert.
The production chain starts with the customer sending 3D-data in IGES format. Wilden determines the shape and number of the electrodes, and design work on tools and electrodes starts at the same time. For some years now, Wilden has been working primarily with graphite as the electrode material, since this saves time during both electrode manufacture and EDM. Manfred Baumann says with a smile: “By using graphite as the electrode material we save all of EUR 100 000 a year.”
It is difficult nowadays to imagine minimised tooling-up times and downtimes without an integrated system for workpieces and electrodes. At Wilden, they decided early on to acquire mechanical interfaces with the necessary stability, accuracy and versatility. System 3R’s Macro reference system (for the electrodes) and its Dynafix reference system (for the workpieces) are used throughout the entire production process. The reference systems do more than link the entire production process together; they create the preconditions for reproducible and unmanned production.
This flow also includes all specific data for every workpiece, every electrode and every machining operation. In the presetting station, which uses AGIE CHARMILLES SIGMA software, all workpieces and electrodes are located and registered, with reference point, offsets, drawing number, part number and machining program, by means of an ID chip with a unique identity.
All pallets with workpieces and electrode holders can be loaded chaotically in the magazine of the existing System 3R robot. As soon as the magazine door closes, an automatic scan is activated to identify loaded workpieces and electrodes. The operator then determines the order of priority of the jobs, to suit the requirements of production planning. And Gerhard Luber, production manager explains: “Our EDM department is a self-managed group, with every employee involved. The result of the great flexibility during preparation and machining is that the average machining time exceeds 6000 hours a year. And with the highest possible process safety.”
Gardena was able to produce the first parts in the tools ten weeks after the order was placed. Electrodes, electrode drawings with the necessary data, and NC programs, were delivered with the machine. “If the need arises, they can make immediate repairs to the tool or component parts themselves, on site. Further proof of the service-friendliness of Wilden tools,” adds Gerhard Luber.
In the intensive competitive situation in the present market, Wilden needs the greatest possible flexibility and efficiency, with no sacrifice of quality, customer satisfaction or profitability. “For mould and tool manufacturers like us,” Manfred Baumann explains, “this means that we must exploit every possible synergy in the process. Shorter lead times in every step, if the step cannot be totally done way with. Enter data only once, to avoid potential errors and to save time. And striving for unmanned machining 6500 to 7000 hours a year, compared with 1600 manual hours a year.”
The tool for the garden shower grip
Could Wilden improve its production efficiency even more? Manfred Baumann – “Yes, we have concrete plans. They involve a systematic increase in the degree of automation, with more versatile and powerful robots in complete integrated production cells. Milling of harder materials must be included in the process chain. And all machining must take place on the same clearly identified pallet. This is our chance to develop our operation here in Oberpfalz, Bavaria.”
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Related links:
WorkShopManager
System 3R Automation
Macro
Dynafix