DIALOGUE WITH Nexans
Nexans is among the leading suppliers of cables and offers solutions for all application areas. Whether for the office, energy provision, building technology, transportation, automotive or industry – Nexans cables and cabling systems ensure the secure transfer of energy and data.
MR SCHULTE, HOW LONG HAS NEXANS BEEN OCCUPIED WITH THE TOPIC OF AUTOMATION AND WHAT ARE THE REASONS BEHIND THIS?
That’s a bit of a long story. The component, which is produced in an automated way here, has already existed in this form on the market for more than 40 years. It’s a 250 connector that is required in various application areas.
It was originally produced in the United States. However, in the 1970s, the decision was taken to make the connector available in Europe as well, and to produce it here at the site in Belgium. The connector design, tools and concept for this were “simply” copied, then applied to round-table machines from DESMA and produced there. The connector consists of three elements, but producing them requires three different machines, each with its own machine operator. It was necessary to perform many tasks manually for reworking, e.g. demoulding, deburring and grinding.
Moreover, cable manufacturers, i.e. the buyers of the connector, developed their cables further over the course of time, which meant quite a lot of variant diversity as a result of modified cable diameters and other specifications and options. The connector was designed in such a way that it was produced with all the options although it was not possible for all customers to use all these options, nor did they necessarily want them, yet they had to bear the costs. To cut a long story short, as a result of the scenario described, it was becoming more and more difficult to competitively offer the connector at this site in the long term. That’s where the idea came from to automate production and considerably reduce the complexity of the process – also for the machine operator.
IN MY MIND’S EYE THIS APPEARS TO BE RATHER DIFFICULT. HOW DID IT PROCEED?
Well, we came up with an idea of how we could set up production, and first developed different concepts, considered various technologies and talked to potential suppliers. The old plan was to produce the component in different stages. To clarify, stage one was produced first, then stage two and so on. But this three-stage process had a few kinks in it. Small deposits of material residues at the parting lines acted like antennas in the electrical stress test and caused the component to fail. These deposits had to be removed by hand. Automatic deburring, however, would have added further peripherals to the system, and we wanted to avoid this.
It was a tricky situation – but one day we happened upon an ingenious idea. We decided to completely rethink the production process and tipped the whole thing upside down. This made it possible for us to produce the component without those electrically unpopular deposits and forgo any additional grinding systems or suctioning.
So we decided to turn the technology completely inside out and now had to find a supplier who would go along with this groundbreaking idea. You can just imagine the effort it took to convince everyone on both sides – after all, we were in the middle of completely realigning a process which had been in place for more than 40 years and would need to use new materials, validate new machines and, to top it all off, automate the whole process. But with DESMA we found the suitable partner we’d been looking for to rise to this pioneering challenge.
WHAT WERE THE NEXT STEPS?
Once everyone was on board with this extraordinary idea, a trial tool was produced by us with one single cavity. This is how to ensure that the parts can actually be produced and that they demonstrate the necessary electrical properties. After all, we hadn’t just adapted the processing conditions, but also had to consider the flow characteristics of the new materials being used.
This required a whole lot of engineering and, of course, not everything worked straight away. But after an intensive, three-day test series, we found out how we had to inject the parts and, just a few hours later, the first two functional components, which we named Adam and Eve, were sent to our own onsite R&D lab for the electrical test. Since in subsequent use the component has to be able to withstand voltages of up to 24 kV, it is tested with a much higher voltage – and it passed all the tests.
WHAT ROLE DOES THE AUTOMATION OF THE SYSTEM NOW PLAY?
Of course, up to the first prototypes, you hone away at the tool, the parameters and so one, but you always have an eye on how the parts are to be placed and how demoulding is to proceed. All of the considerations which go into handling must later be feasible for the robot as well. A holistic perspective is necessary, so to speak, in order to account for all interests between human and machine.
The component is now manufactured fully automatically on a system with just one machine operator. Without reworking, which means that the articles actually come out of the system suitable for immediate sale – they’re just visually inspected, electrically tested in our own R&D department and then packed and shipped. Opting for a final visual inspection by the machine operator was a conscious decision. The human at the machine makes sure that the process runs stably, checks the rubber feed and keeps an eye on the machine. Automating all of this may be conceivable – but is it worth the additional effort and expense? We believe that a reasonable balance between human and machine is the smarter choice.
SINCE YOU MENTION STAFF – HOW DO THEY FEEL ABOUT THE TOPIC OF AUTOMATION?
Our staff are in favour of automation and have no problems with it. Quite the contrary, at our company automation stands for modernity and we thus secure our site by using it. This is obvious to everyone. For the co-workers at the system, we offer internal training to help them get fit or keep them fit. Therefore, it was a prerequisite that the control during running production be particularly easy and the alerts issued be clearly understandable so that after a brief initial training period the operator would be able to start the system and also take action in case of malfunctions, without having to immediately request the support of maintenance staff. All of this has to be considered beforehand, and can only be optimally implemented if both parties are able to cooperate smoothly.
PLEASE DESCRIBE THIS COOPERATION IN MORE DETAIL.
We only had one project manager as a contact partner over the course of the entire project. That was agreed upon from the start. Of course, we developed the specifications, processes, acceptance criteria and schedule, and sent them to the various departments – but I always had the same contact person. As a customer, I was permitted an extremely in-depth look inside internal processes, collaboration was very open and the boundaries between customer and supplier were fluid. For projects of this kind, this is also extremely important. None of us had ever done this before and both sides knew how important this development is. Quite simply, this involves a relationship marked by high levels of trust and a willingness on both sides to open up to each other. What we’ve learnt in this project is now flowing into other projects.
WHAT CONTRIBUTION WERE SPECIAL DESMA TECHNOLOGIES ABLE TO MAKE AND HOW WERE THEY ABLE TO MAKE THEM?
Since, as a result of the new materials, we also had to cope with a new flow behaviour, we made remarkably good experiences with the FlowControl cold runner in combination with PressureSense, especially in terms of volume determination. In addition, thanks to QuickLock, it’s possible to change the tool fast. Press two buttons, insert two rods – done. The co-workers who still have to unscrew twelve M16 screws on the old systems in a hot environment sometimes look over this way with envy. And because space is always an issue in a production hall, the compact design of the entire system is, of course, convincing.
YOU MENTIONED BEFORE THAT THE EXPERIENCES MADE FLOW INTO FURTHER PROJECTS. COULD YOU EXPLAIN THAT IN A LITTLE MORE DETAIL?
There are further projects, including automation, which we would like to complete in the future. This includes everything from the idea to the actual implementation. The market in which we’re active is rather conventional. It’s not possible to get it all done overnight since we’ve got an enormous amount of qualification work to do for each and every customer. The parts need to be produced and presented to the market, operating instructions and installation instructions need to be written and so on. For these reasons as well, we’ve opted for a modular solution which makes it possible for us to cover planned requirements with the installation of a second cell. And this again with just one operator at the machine.
WHAT IS SPECIAL ABOUT THIS SYSTEM?
The beautiful thing about this solution is that, in principle, we can copy the basic structure of the system and use it for another article. This is possible because, among other things, you can use all tools intended let’s say for a 400 T machine on all 400 T machines from DESMA. This ensures the utmost in flexibility, which I want for my machine park – and all of it without retrofitting.