BHC Gummi-Metall GmbH
DIALOGUE WITH BHC Gummi-Metall GmbH
BHC GUMMI-METALL GMBH, based in Meckenheim near Bonn, is an innovative, highly specialised mid-sized enterprise for technically sophisticated rubber-metal connections and vibration-control components.
MR KURTZ, PLEASE TELL US HOW LONG YOU’VE BEEN ANALYSING THE TOPIC OF AUTOMATION AT BHC AND WHAT REASONS PLAY A ROLE IN THIS.
Martin Kurtz: We’ve been occupied with the increasing automation of our systems for many years now. In addition to the growing demand for our products, making things easier for our employees has played a major role in the process of deciding which system to consider.
COULD YOU PLEASE EXPLAIN THAT?
Let me give you an example: in our production, there is a DESMA system that we’ve been using for more than 25 years to make rubber-metal parts. Demoulding, i.e. removing the components from the mould, had to be manually performed by a worker after the process ended – but the components weigh up to 3 kg – you can imagine the effort required of the worker. Since the components have to be additionally preheated in a cassette oven, the complicated combination of preheating process, energy-sapping loading and unloading and the appropriate robotics appeared to render any automated solution more or less impossible. Together with DESMA, a solution was nevertheless found that fully automatically mapped this truly hard task precisely and with a high level of reproducibility. DESMA convinced us most of all with the presentation of a complete concept and thus got rid of all our concerns.
WHAT DID IT LOOK LIKE?
I always compare it to a well thought-out triad. Normally, with this production system, several interfaces need to be harmonised at once – cassette oven, robotics and the injection moulding unit itself. In addition, ergonomic handling must also be ensured – no easy task. The components weigh up to 3 kg and that corresponds to a total weight of almost 3 tonnes per shift that need to be removed by the worker. And that combined with very high ambient temperatures and unpleasant noise levels and smells.
Coordinating all these specifications with different manufacturers would have been too much work and therefore impossible – because, in such complicated projects, responsibilities are often not defined clearly enough. The DESMA solution makes it possible to consolidate monitoring of the heating process, automatic demoulding and robot programming in a single controller. That made a lot of things simpler.
MR SARIDAG, WHAT DIRECT ADVANTAGES ARISE AS A RESULT OF THIS AUTOMATION SOLUTION?
Irfan Saridag: We were able to use our previous insights made with the robot of the existing machine to programme the new robot. For example, the robot’s behaviour was modified so that, in case of a collision, the robot would no longer completely interrupt the product cycle, instead the robot ignores the component in question and simply continues with the remaining components that have been correctly placed. This considerably increased the runtime of the robot and the corresponding output.
Since now all components, e.g. switching the cassette oven on and off and its temperature control, are also monitored via the DESMA controller, this gives us additional advantages. The risk of components not being preheated properly or being placed in the system when they are too hot is eliminated. The system detects when an alert is issued that a heating rod is defective and, as a result of cycle time monitoring, the machine always knows which parts need to be taken out of the four cassettes first. The stability of the cycle time is thus much more continuous. The cassette oven supplier was supported by DESMA for the integration in the DESMA controller and thus the supplier knew exactly how he was to prepare his oven.
HOW WOULD YOU BEST DESCRIBE THE COURSE OF THE PROJECT?
Not even 12 months passed from the initial idea to the final acceptance. It definitely plays a role that we always had one and the same contact partner from DESMA at our side. After the idea stage, we were shown an initial setup on the display via a CAD demo. One important aspect was, of course, the simulation of the cycle time calculation. Our specification was, of course, that the new cycle time had to at least correspond to the old one, and that the robot had to work fast enough to ensure that, despite the additional removal time (this had previously been done manually by a worker), it remained within the heating cycle. All of these provisions were more than met.
And there was another positive side effect: the calculations resulted in the heating cassette being angled and not positioned parallel to the system as originally planned. This made it possible to avoid forces which would have had an unfavourable effect on the joints of the robot. The robot is also integrated for all intents and purposes according to its own ergonomic requirements.
The demo also helped in understanding what the conveyor length and speed are needed for removal of the components chosen, what space requirements will be the case and what the corresponding safety concept will look like. When you work together with a company like DESMA, you can be sure that you are always working with your finger on the pulse of the times. Also in terms of safety requirements, which we all know are always changing, DESMA is always right up to date. Thus, everything was recalculated and a completely new safety concept was presented, and the system was equipped with intermediate rails, a complete protective enclosure, light aprons and a multifunctional door-closing system. We received an all-round carefree package.
WHAT HAPPENED TO THE ORIGINAL TOOL OF THE ORIGINAL MACHINE?
Of course, it was a further requirement that the existing tool be reused. The adaptations were arranged for from the start. As a result of the close collaboration with the DESMA mould shop, the necessary modifications to the injection channels and dimensions were perfectly adapted to the new working environment.
ARE ADDITIONAL QUALIFICATIONS REQUIRED FOR OPERATION OF THE FULLY AUTOMATED SYSTEM?
Meanwhile, as a result of the simple user interface on the touch panel, 20 of our employees are able to operate the robot. We acquired this expertise within the scope of onsite training. If situations arise that we cannot resolve on our own, phone-based assistance is available via SmartLine, which always provides us with fast professional support.
ONE QUESTION TO SUM THINGS UP: WHAT WOULD BE A CRITICAL FACTOR IN A DECISION TO OPT ONCE AGAIN FOR AN AUTOMATION SOLUTION FROM DESMA?
There are many manufacturers of injection moulding machines, but none that can boast such a wide scope and experience. You actually get a complete turnkey solution from a single source. That’s decisive for us.
As a result of the simulation, it was possible to ascertain considerable potential for improvement. Thus, the walking distance between the operating panel and the cassette oven was considerably shortened. Operating or programming the robot, oven and injection moulding machine using just one unit makes working at this system so simple that all of our staff want to work with it.
Further automation potential is currently being identified and will be implemented in the near future together with our partner DESMA as a turnkey provider.