Four firms partner to install new G3 internal mixer at WAGU

WARSTEIN-BELECKE, Germany—After many years of use, it was already time for WAGU Gummitechnik GmbH to replace an ancient internal mixer.

The core of a new rubber compounding plant at WAGU's site in Warstein-Belecke consists of a new internal mixer from Castel di Lama (AP), Italy-based G3 S.r.l.

The construction of the new rubber mixing plant at WAGU was coordinated by Nuembrecht, Germany-based Mabolution Biegale & Partner. The project involved close and well-coordinated cooperation between G3 Mixing Technologies, as the manufacturer of the internal mixer, and two German companies: Rautec, and Nienburg/Weser-based CT Datentechnik GmbH.

Rubber News was present at the start-up of the plant earlier this year and talked about it with managing directors of the companies involved.

Rautec was responsible for development and configuration of the process control system and ensured it ran smoothly at WAGU during commissioning. All recipe components and processing parameters are monitored, controlled and used to adjust and optimize the mixing process via the operator panel, which is programmed with Simatic P.L.C. software from Siemens. Rautec has been certified as a "Siemens Solution Partner Automation Drives" since 2007.

The G3 internal mixer is located on the first floor, directly under the place where, one floor higher, various recipe ingredients and mineral fillers are manually thrown into the mixer from sacks or bags via a chute. At the time of the visit, the plant was started up and ran an EPDM-based compound. WAGU Managing Director Tobias Nonnast confirmed that the two silos visible at the WAGU site are filled with carbon black and silica, and are dedicated to compounds for a single large customer.

WAGU has a total of four rubber compounding lines equipped with internal mixers. These are Line 1 with an online strainer, for light and colored rubber compounds; Line 2, also with an online strainer, for black rubber compounds; Line 3 for bulk and fiber-filled compounds; and Line 4 for fluoroelastomer (FKM) compounds.

Online straining through 0.1 to 0.8 millimeters screens is used by WAGU for the most demanding, ultra-fine compounds, such as for membranes or webs.

Other processes at WAGU include extrusion of blister-free rubber sheets, calendering rubber sheets, vulcanization of calendered and extruded sheets, production of zig-zag skins, and of rubber granules as 5 mm x 5 mm cubes by horizontal cutting rubber sheet strips. WAGU produces both standard compounds and niche products.

WAGU already has been subjected to a sustainability audit by EcoVadis and successfully passed with a silver award in 2020. Various ESG factors were evaluated, and the audit included not only ecology, social and corporate governance, but also WAGU's monitoring of sustainability of its global supply chain.

Unlike some other companies audited by EcoVadis, WAGU cannot use solar panels on the roof to perform better in the area of the environment because "solar panels are too heavy for that," Nonnast told Rubber News.

Pierpaolo Gagliardi, managing director since 2002 of G3 Mixing Technologies, said his company has offered a comprehensive service to the rubber industry right from its founding in 1953, including reconditioning used machines. This activity led to the acquisition of Italian machinery producer Italmec in 2005, "and through their expertise in turning and milling metal, we learned how to design and produce new machines," he said.

G3 had focused on internal and external mixers already for a long time, with tangential counter-rotating, intermeshing screw internal mixers having become a particular G3 specialty. And it is this type of mixer that has now been installed at WAGU. The new mixer at WAGU has a chamber volume of 110 liters and internal clearance around the screws of 86 liters, according to WAGU Operations Manager Mike Raszpir.

Rautec was founded in 1991 and is owned and managed by the Repohl family. The 20-employee company has carried out 76 projects since 2021, other than WAGU. The most important Rautec customer is Hanover, Germany-based extrusion machinery and equipment producer Troester GmbH & Co. K.G.

Troester, incidentally, built and supplied a 30-meter long highly automated, combined roller head and calender line in 2022 for WAGU. This new line represented the largest single investment for WAGU and replaces two old lines: a roller-head line and a separate four-roll calender. The line runs at speeds of 1.25-25 meters/minute to produce precise extruded and calendered rubber sheets in 0.3 mm to 21 mm thickness to ±5 µm tolerance.

WAGU said the line has enabled a broader product portfolio for customers and more application possibilities.

Rautec has extensive experience in supplying systems for rubber processing. For example, Muendener Gummiwerke was one of the first customers for the Rautec BLS batch line control system for order and recipe management, as well as batch and production data acquisition in rubber production.

Although Rautec previously was active in control cabinet construction, the plant control cabinet in the new mixing plant at WAGU comes from CT Datentechnik, and is fully equipped with all kinds of electrical and electronic components. CT Datentechnik also is a family business and has installed automation solutions for more than 100 rubber mixing lines since it was founded in 1989.

CT Datentechnik Managing Director Christian May also was present at the commissioning of the internal mixer at WAGU. The CCS2000 Compound Control System installed by CT Datentechnik at WAGU for the new internal mixer is a process control system that provides complete monitoring and control of all processes within the mixing plant. According to CT Datentechnik, the software ensures quality-assured automation of various production processes "from raw material to finished product" and is mainly used by rubber compounders.

WAGU's Mike Raszpir emphasized that, given the increasing importance of carbon footprints, data collected in the new mixing plant is very helpful as part of WAGU's plant data acquisition (PDA), as it also allows, among other things, to calculate specific energy consumption for each of the many rubber compounds. The firm tests all batches during production, resulting in creation of process, weight, hardness, density and rheology Mooney viscosity data documentation.

Nonnast previously worked in the rubber industry at Hanover, Germany-based Continental A.G. and joined WAGU in 2010. He said WAGU has around 5,000 recipes and that 10,000 metric tons a year of materials are mixed at the company into 1,600 different rubber compounds. Having a well-functioning and controllable PDA is therefore extremely important, as it needs to process more than 2 million data records/year, including data on raw materials, weight measurement, the mixing plant, laboratory and customer shipment data.

Nonnast added that WAGU achieved record results in both 2021 and 2022. As a result, "the business is doing very well, supported by a total of four compounding plants." The G3 internal mixing plant replaced an ancient plant that was no longer in good condition.

"We had been looking around for a replacement for quite some time," Nonnast said. "We were very open to alternatives, but knew that two of our customers who also produce rubber compounds, bought internal mixers from China and had to replace them after only two years. We ourselves had experience with a roll mill that we received from China, and had to rework the roll mill ourselves. We also had to replace the control cabinet and the control system for the roll mill".

Maurice Biegale of Mabolution Biegale & Partners described during commissioning how the project was initiated. The three project partners and WAGU met together in November 2021 at G3 Mixing Technologies in Italy to prepare for a possible order from WAGU. After the bid was submitted, WAGU placed the order in February 2022 and was eager to have the plant up and running by early 2023.

Despite delivery difficulties, the partners were able to deliver the entire plant to WAGU on time in December 2022, shortly before Christmas. All that remained after that was to perform the installation, targeted for commissioning the following month. Not an easy task, but one that was nevertheless accomplished. Biegale noted, "The last three years have been very difficult for all of us because of COVID and supply chain issues," he said. "Importantly, WAGU said they wanted to get the mixer in 2022 and we delivered on time".

Raszpir added: "I visited G3 Mixing Technologies in Italy in November 2021, and G3 convinced me that they could build an internal mixer in a good way. Besides, since Rautec and CT Datentechnik were already usual partners for us, we didn't expect any extraordinary changes from them."

Biegale said that while the mixer was made in Italy, it was important that the control system for the plant came from local companies. Raszpir said that both Rautec and CT Datentechnik faced some difficulties in the supply of components, but nevertheless overcame these problems.

Nonnast said the project went smoothly, with all the partner companies in sync. "We never had the impression that we were dealing with four companies, as everything went smoothly through Mabolution," he said.

About the new internal mixer, Nonnast said, "I was also very impressed that the internal mixing plant arrived at our plant in Warstein within nine months from order placement to delivery and could be installed immediately. It can make all kinds of rubber compounds, in colors ranging from white to anthracite to yellow, and it can also handle relatively hard compounds with high filler content without any problems, because it has a very powerful motor".

Raszpir said the new G3 mixer gives WAGU possibilities to produce many additional rubber compounds.