The Thuringian town of Zella-Mehlis, Germany, is home to one of the most advanced extrusion facilities. Here ultra-thin aluminum tubes are coated with several layers of plastic. Formed and heat-sealed, the result is a multilayer composite piping product for heating and drinking water applications – produced at a rate of up to 60 meters of pipe per minute.
“We are the competence center for multilayer composite piping of Uponor,” says Stefan Häfke, Quality Manager at the Thuringian location of the Finnish plumbing and HVAC specialist Uponor. What distinguishes multilayer composite pipes from all-plastic ones is that they are shape-retaining. “When the plumber bends the composite pipe to fit the installation, he can be sure that the pipe will not move but remain exactly in that position,” explains Häfke.
Since the pipe specialist introduced a new technology in the production of its OD 16 to 32 mm pipes, the production speed has almost doubled. The existing inspection systems used in quality control were unable to cope with this high rate. In 2020, the company considered the investment in new inspection technology and chose the new Two-in-One system, AllRounDia DualVision (DV), from measuring technology specialists PIXARGUS, based in Würselen, near Aachen, Germany.
This compact and at the same time versatile instrument is the first 360-degree inspection system for round products combining both surface inspection and dimension measurement simultaneously within one sensor head and showing the measured data immediately in real time on the display. The first system has now been in operation at Uponor in Zella-Mehlis since August 2020. It passed the acid test with flying colors.
Quality Manager Stefan Häfke knows how exacting the quality requirements in this industry are. Out of its production facilities in Zella-Mehlis, Uponor supplies wholesalers in Germany and the rest of Europe. The pipes are used in service ducts, in floor heating systems, drinking water systems installed in the wall or surface-mounted “The customer expects a visually impeccable product,” says Häfke. But technical integrity is just as important. Cracking phenomena on the pipe surface, for example, resulting from fused foreign substances, may negatively affect the pipes’ shape-retaining capacity and cause breaking of the pipes at these spots. “To avoid this, we need 100 percent flaw detection, missing out not a single spot of the surface,” adds Häfke.
Another important aspect for Uponor was to get a system that was Industry 4.0-ready and proof. A system based on Windows, AllRounDia DV could be easily linked with the components of the production line, enabling the control system to retrieve the quality data generated by the gauge. “When a defect has been detected, we can immediately take action, switching automatically to the scrap mode, for example, to eject the defective product,” explains Häfke.
In addition, Uponor uses the quality data available thanks to the new PIXARGUS system to optimize the production process. Process parameters provided by the software can be analyzed over time and related to one another. “In this way we see whether certain machine settings lead to more or fewer defects. And this knowledge enables us to refine our recipes, for example.”
The system requires virtually no manual adjustments. “Whether the lighting or the setting of the camera angle: everything adjusts automatically. The functionality is straightforward. In other words: AllRounDia DV checks exactly what is relevant for us. And from this our customers benefit just as well.” This is where quality manager Häfke sees one key advantage of the PIXARGUS system.
PIXARGUS has designed their new series of compact systems with a focus on the essential. “Reduced to the max”: this is how PIXARGUS calls this approach. Sales Manager Michael Frohn: “For us, high-performance technology and compactness of design are two things that go very well together.”
For AllRounDia DV, the German measuring technology expert has optimized and adapted its successful ProfilControl-7 technology to achieve a system that concentrates all its capabilities on the measurement of simple, round geometries. “The system can measure the diameter, ovality and inspect the complete surface area of round extruded products for a wide range of materials,” Michael Frohn continues.
While the system’s big brother, ProfilControl 7, uses an external encoder to send the scan signals to the camera, in the AllRounDia DV this is handled by software. ”For us, it was important to design a system that would have no additional hardware to be added and removed or set up by the customer. This makes our system extremely versatile, and it can be easily moved over to another line,” Frohn adds. PIXARGUS is ready to take their series of compact gauges to the next stage, making it possible for the customer to commission the system without the support by a technician. “Our aim is to offer our customers Plug & Play – at an attractive price,” says Frohn. “
However, no compromises will be made on the technological performance. AllRounDia DV uses “real” LED light for the surface inspection, not laser light as conventional system do. Thanks to the application of laser triangulation in the camera-based dimension measurement, round and oval contours can now, for the first time ever, be measured gaplessly around their complete circumference. While conventional axis-based measurements using the shadowing method cover only six single points, the optical sensors are able to capture 4 million pixels. “This enables us to measure much more accurately and reliably,” Frohn comments.
Meanwhile everything has been going on according to plan at the facilities in Zella-Mehlis. After the successful commissioning of the first system, Uponor is expecting the next three AllRounDia DV systems to arrive soon.
