Automatic inline quality control

Gerodur MPM Kunststoffverarbeitung GmbH & Co KG, a subsidiary of HakaGerodur AG (Gossau/Switzerland), is a specialist in producing plastic products for piping systems and heating and sanitary.

Since 2017, the company located in Neustadt/Saxony, Germany has been using millimeter wave technology from SIKORA AG for the measurement of the wall thickness, diameter and sagging of plastic pipes during the extrusion process. The cooperation between the two companies is based on a future and also practice oriented solution for an automatic inline quality control in order to ensure the highest pipe quality and optimal processes. 

Wherever reliability, wear resistance and corrosion resistance are required, plastic pipes are the best choice. Whether as piping systems for transporting water, sewage and gas, or for transferring drinking water or for heating and sanitary facilities, quality requirements of the pipes are very high and determined by standards.

Since the foundation 26 years ago, Gerodur has been producing first-class plastic pipes with the focus on the highest product quality, optimal processes and profitability. For the internationally operating manufacturer, the application of innovative measuring and control technology in extrusion lines is a matter of course. The first contact with SIKORA, manufacturer of measuring and control devices from Bremen, was made several years ago.

At that time, Gerodur was looking for measuring technology for smaller product dimensions in the area of heating and sanitary facilities and found the solution in X-ray technology. For two years now, the company has also been using a new technology from SIKORA that is based on millimeter waves and which is applied during the extrusion of large plastic pipes and thus follows a future-oriented approach.

“There are several methods for quality control on the market. The newly developed millimeter wave technology convinced us with its smart measurement principal”, says Andre Richter, Team Leader of the division piping systems at Gerodur. “Especially for the measurement of large pipes in the dimension range of 250 to 630 mm and wall thicknesses of up to 60 mm, we see significant benefits”, he continues.

In the line, the millimeter wave system CENTERWAVE 6000 is installed directly after the first vacuum tank. The system measures over 360 degrees of the pipe circumference the diameter, ovality, wall thickness and the sagging in real-time and, thus, enables a fast centering of the extrusion tools. An alternative measuring method on the market is ultra sound.

This technology also measures the pipe diameters, however, due to its temperature dependency, it can only be applied later in the production process.

“It is our goal to receive reliable and accurate information about the pipe dimensions as early in the process as possible in order to take actions if necessary. Thereby, an early measurement of the wall thickness is of significant importance considering that pipes with large diameters and large wall thicknesses are being produced at a line speed of 0.5 meters per minute”, adds Richter.

An optimized start-up process – meaning time saving and manufacturing at nominal dimensions while, simultaneously, avoiding waste – leads to process reliability and an efficient production, which is often crucial with regard to competition. Gerodur understands its business as a continuous improvement process.

“We constantly review our processes and also break new grounds if this enables us to further increase customer satisfaction”, explains Axel Mantey, Managing Director of Technology at Gerodur.

“In addition to quality, the highest delivery reliability and flexibility concerning customer requirements are important aspects.” Thus, the company has launched two innovative products, which opened up new application areas.

Gerodur also places high demands on its suppliers. Process technology, which includes measuring and control technology, is a crucial component within the value-added chain. The data supplied by the measuring technology is the basis for process improvements and has an impact on business correlations within the company.

“We are in close exchange with SIKORA and develop further together. For example, we are discussing ideas to adapt the system to our line requirements even after purchasing the device. This applies, for instance, to customized software modifications or individual visualizations of measurement data to support the operator”, explains Mantey. The results are optimal processes and high productivity.

At Gerodur, the production of high-quality products and process optimization will continue to be at the top of the agenda in the future. „Besides technical innovation, industry 4.0 and digitalization will be long-term challenges”, says Mantey. In extrusion lines, various machines, devices and systems are integrated that supply different data.

A particular challenge is to evaluate and process these amounts of data that have to be intelligently reduced to be perceivable for human. “Thus, the cooperation with machine manufacturers and manufacturers of measuring devices, like SIKORA, will play a key role”, says Mantey. SIKORA’s millimeter wave measuring system is well equipped with regard to industry 4.0 and already provides interfaces such as OPC UA and industrial fieldbus connections to be networked with the production plant.

Axel Mantey is convinced that the combination of future-oriented technology with proven functionality and reliable service makes the cooperation with SIKORA so valuable. “If we achieve more process reliability by using measuring technology and produce a perfect pipe at the end of the production line, not only our customers will be satisfied, but we will be too”.