Extrusion machinery company Hans Weber Maschinenfabrik GmbH has been implementing digital tools to help its customers improve sustainability.
In a Q&A from German industry group VDMA, Simon Bard, product manager for extrusion at Hans Weber talks about how technology can help advance better production.
Q: How does digitalization in extrusion contribute to sustainability?
Bard: Companies are increasingly concerned about sustainability, with many measuring their carbon footprint. When we extrude window profiles, today’s customers want to know the exact emissions involved in the process, how much energy has been utilized, and so on. In the past, hardly anyone showed an interest in that aspect.
We have developed a digitalization solution, resulting in us being able to provide these precise answers, such as how much electricity was consumed per meter of window profile on "Day X." However, this is not limited to telling them the current status quo, but also how to improve something in the production process. For example, how to save energy and avoid emissions. With our digitalization solution, we can turn the screws to avoid wastage.
Q: How do you achieve that?
Bard: We record key figures; that is the prerequisite. Based on these key figures, you could, for example, replace the screw in the extruder and see if you use less energy. During extrusion, you first put a lot of energy into melting the plastic. In the final process, you have to cool the plastic again so it can regain its shape, however, you can synchronize the parameters to reduce the power consumption to a minimum. Previously, the desired temperatures were entered by employees, mostly by instinct. One employee from one shift would set the temperature in the cooling zone to 190° C, the employee of the next shift then set it to 200° because they felt that was best. With our digitalization solution, we can determine and set the optimal temperatures.
Q: What does this solution draw on?
Bard: Interconnecting the different machines is the first step. We have many different manufacturers in the extrusion line. So far, they have communicated little with each other, plus there was no higher-level control system in place either. Now we have the possibility of collecting data on the entire line, evaluating it, finding the optimum levels, and then controlling it accordingly. We have defined our extruder software as the starting point for the entire control system. To do this, everything must first be linked up, and the data must be issued accordingly.
Q: To make this work you’ll need the various machine manufacturers to cooperate.
Bard: Yes, and technically they should all speak the same language. That's why we are working on further developing the OPC UA standard, as many machines can't do that yet. That's why we need a translation box that translates from the proprietary language to OPC UA. But we are working towards ensuring that our suppliers and all machine providers in this production line also master this language. In injection molding, we had the adaptation to this standard first. In extrusion, less than half of the manufacturers of saw, haul-off, water bath and so on currently speak OPC UA. It will be a while before everyone speaks this language within extrusion.
Q: But the benefits would be considerable?
Bard: The benefits would be enormous. Today, the cost of installing our software is much higher than the software itself. This is because without a plug-and-play solution, we have to integrate each machine individually. So, it will take a major effort before all the aggregates communicate with each other.
Q: There is already a circular economy for window profiles. Why is this field already so far advanced?
Bard: This is mainly because you always have the same material, namely PVC. Moreover, you know that the additives you have to extract for recycling are always the same, too. For example, titanium dioxide to protect the profile from solar radiation. Of course, all this makes recycling easier. In addition, we already have a well-functioning waste system for the profiles. More than 50 percent of all window profiles already contain recycled material. However, it has to be said that these do not primarily come from old window profiles, but are largely obtained from leftover pieces resulting when window profiles are cut to size by the window manufacturers. However, recycling of old windows has been pushed forward recently because prices for virgin plastic have risen sharply. If prices stay this high, it will become increasingly important to recycle every gram of plastic.
Q: Where does digitalization at Hans Weber go from here?
Bard: After collecting data and then optimizing certain parameters, we are now thinking about how we can make the extrusion process run completely automatically. The goal is for the user to just press a button, and for the entire process to then run optimally. In case of an error, the system should be able to recognize the reason and correct it. But it will still take some time before we’re at that stage.