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Everything is running smoothly at cable manufacturer Huber+Suhner. Every process in the production facility is in place - from delivery of the copper wire to the finished reel of cable. This is also necessary, because the high-tech cable from the Zurich municipality of Pfäffikon has a considerable amount to withstand: when it is used as inter-carriage cable in trains, it still has to work in extreme cases. It does this thanks to special treatment with electron beam cross-linking. The plastic is blasted with electrons and made «unmeltable». This gives the cable a sheath that withstands extremely high temperatures.
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In the factory, costs are kept down by an on-demand system, low warehouse stock and a high degree of machinery utilisation. In spite of this, Peter Schmollinger, process technology manager at Huber+Suhner, is always thinking about the individual stages of the process. On the one hand, because it is his job to improve existing processes and develop new ones, and on the other hand because the company puts value on investigating the ecological effect of the processes.
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«Companies are aware of their material and salary costs. But what costs are generated by clandestine energy consumers?», asks Schmollinger. He wants to know the facts: does it make ecological sense to keep the plastic permanently warm in the extruder that puts the sheath on the copper wires? Or would it be more sensible from an energy point of view to allow the polymer compounds to cool during breaks in production and heat them up again as required?
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Are there any alternative drying methods? Can they be operated in a financially viable way, and will it be possible to manufacture the same amount of cable in the same time using these methods? Schmollinger is sure about one thing, though: «No company wants to have a green factory that doesn't earn anything».
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Wherever possible, individual stages of the process would also have to be arranged differently in accordance with ecological aspects, considers the precision mechanics engineer. In Pfäffikon the cable runs through a water bath for cooling after the sheath has been extruded. A few metres further on, it is dried again by a high-pressure air dryer. Is that more efficient from an energy technology point of view, or could the cooling and drying resources be arranged in a more resource-friendly way?
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«EcoFactory» combines financial and ecological aspects.
As a process engineer, he has a feeling about the direction in which things need to go. But now he is hoping to receive some more objective feedback by means of the joint «EcoFactory» project with Empa and the ETH Zurich. The heart of the project consists of software that simulates how to set up and coordinate processes in the best possible way, in order to achieve financial and ecological targets as a company. And exactly this "not only – but also" between market and environment is the new thing about «EcoFactory»; the program does not just simulate financial parameters such as utilisation, timing and idle times (i.e. the entire profitability aspect) but models, evaluates and optimises process with regard to sustainability. Anyone who wishes to arrange processes in an ecologically better way in a production facility is quickly confronted with ecological balances, dealing with resources, CO2 emissions and waste disposal - all of which are extremely complex topics.
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Empa know-how regarding life cycle assessment
And this is exactly where Empa comes in: The Empa researchers provide their expert knowledge on life cycle assessment and the «ecoinvent» database (see box). They have many years of experience with systematic analysis of the environmental effects of products during the entire lifecycle. «We actually look at things in a similar way to the economists», says Empa researcher Rainer Zah, ecological balance expert, «we also always examine the entire process creation chain». |
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| According to Zah, many manufacturing companies would have realised that they should integrate the ecological perspective in the process management, which has been financially driven in the majority of cases to date. Where do we start? For example, if they want to purchase a new, more efficient machine, they need to know whether they can save money with it, and also if they will consume less energy and auxiliary materials and can comply with the legal limits. |
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| This is where the EcoFactory software can help in the future. If the financial model is directly coupled with the methods and data for life cycle assessment, companies can determine which machines are running when and for how long in the production process, and which materials they require. They can also simulate emissions, reveal resource consumption and collect waste materials. Because the ecological dimension is by no means restricted to energy saving, says Zah. |
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| When the project is completed at the end of 2013, the tool if going to be developed to such an extent that it can be introduced commercially. Larger companies with their own environmental department can use the tool themselves, and SME's should approach energy agencies with their specific questions. ETH and Empa employees now (at the half-way stage) visit their industrial partners on frequent occasions. «These are all companies, that are already a step ahead in corporate environmental protection, but want to go a step further», states Zah. «It makes the work extremely interesting.» |
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Data collection and evaluation
As an industrial partner, Peter Schmollinger of Huber+Suhner currently makes «his» processes available for systematic recording and analysis. The ETH team recorded a full week of production at the end of May, during which about 3500km of high-tech cable was manufactured. They recorded every individual work step at one-second intervals: during extrusion, water cooling and electron beam cross-linking. In this way they collected key data about energy consumption, emissions, water usage and material flows. |
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| Once all of the pieces of the puzzle have been assembled, new processes in which the work steps take place in a different order are simulated, and the best financial viability is determined. Huber+Suhner has more than a dozen similar cable manufacturing plants to which the optimisation could be transferred. And, of course, the findings could also be applied to new production facilities. Even in special cases, such as the new electron beam cross-linking system next to the factory building, where the walls will be extra thick, so that high performance cables can be refined in high vacuum. |
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