Degreasing system using a hydrocarbon-alcohol mixture as the cleaning medium

A degreasing system that uses a hydrocarbon-alcohol mixture as the cleaning medium achieves a high level of cleanliness for precision parts. Close collaboration between the solvent and equipment manufacturers reliably optimized the cleaning process.

Richard Geiss GmbH, with its RG4Chemicals brand, has made “Everything from a single source” its motto. Helmut Mühlberger of Rosenberger Hochfrequenztechnik GmbH & Co. KG, headquartered in Fridolfing (Upper Bavaria), can attest that the solvent specialist based in Offingen (Bavarian Swabia) delivers on this promise in practice. “Richard Geiss GmbH and the equipment manufacturer Vapic supported us as strong partners on an installation project and proved that we can rely on them completely—especially when things get tricky,” explains Mühlberger, group leader for individual parts manufacturing at Rosenberger. The Rosenberger Group employs more than 15,000 people worldwide. At its headquarters in Fridolfing alone, approximately 3,500 people work on the company’s approximately 133,000-square-meter campus.

In the summer of 2023, the leading provider of connection solutions for high-frequency technology commissioned a new degreasing system at its production site in Fridolfing—with one unique feature: For the new system, Helmut Mühlberger and his surface technology team deliberately chose a hydrocarbon-alcohol system using Isoclean RG 59 from Richard Geiss GmbH as the cleaning medium, in order to be able to utilize the full range of cleaning solutions in the future. In Fridolfing, there are already four degreasing systems that use perchloroethylene (PER) as the cleaning medium, one hydrocarbon system, and one closed vacuum system that uses an aqueous-based cleaning solution. All systems installed at Rosenberger in Fridolfing were supplied by Vapic, a renowned specialist in industrial component cleaning based in Neubulach, Baden-Württemberg.

The demand for degreasing is enormous: In fiscal year 2025 alone, Rosenberger cleaned two billion components in Fridolfing; every month, more than 130 million connectors for high-frequency technology pass through the various degreasing systems. There is currently a boom in measuring devices for AI chips, which Rosenberger also develops and produces in Fridolfing. Degreasing operations in Fridolfing are running at full speed around the clock, six days a week, in 6/24 mode. Commissioning the latest KW alcohol system proved to be trickier than originally planned. “Together with Richard Geiss GmbH and Vapic, we managed to develop a stable process that leaves nothing to be desired. The high level of commitment from everyone involved has truly paid off. Now, with the KW alcohol solution, we’re achieving the same quality and surface tension as with a PER system,” says Mühlberger.

Since Rosenberger supplies its components not only to the automotive industry but also to the aerospace, telecommunications, and medical technology sectors, the requirements for the degree of cleanliness during degreasing are particularly high. “It was clear to us from the outset that the degreasing process at Rosenberger, using a mixture of hydrocarbons and modified alcohols, would be more sensitive than the conventional degreasing with PER in the systems previously installed. This meant we had to invest even more effort into the continuous monitoring and optimization of the process,” explains Lech Andrzejewski-Eser, the account manager for surface cleaning at Richard Geiss GmbH.

At the height of the analysis, Markus Obermayer, Project Manager for Process Optimization at Rosenberger, and his team reported the readings from the solvent bath to the experts at Richard Geiss GmbH on a daily basis. “The response came back immediately: ‘Okay, add 150 or 200 ml of stabilizer now.’ We’ve now optimized this process so that the stabilizer is added at fixed intervals spread throughout the day,” says Obermayer. During this phase, Rosenberger made constant use of the Quick-Test kit for on-site analysis of the solvent bath based on Isoclean RG 59. This test kit is equipped with all necessary measuring instruments, test reagents, and operating instructions for independent on-site solvent monitoring. “Our team now knows the testing process by heart, since we’ve also been monitoring our PER systems for many years using the three-step test kit from Richard Geiss,” explains Obermayer.

During the process analysis of the new KW alcohol system, Markus Obermayer and Helmut Mühlberger benefited greatly from the comprehensive service provided by Richard Geiss GmbH: The specialists at the Geiss laboratory continuously analyzed samples from the solvent bath, provided the correct recommendations for stabilizer additions, and monitored safety during the degreasing process.

In addition to the comprehensive support services for system installation and the cleaning process in Fridolfing, Rosenberger also utilizes the contract cleaning services offered by Richard Geiss GmbH. “That really helps us a lot. Especially when it comes to purchased parts—which we don’t produce ourselves in Fridolfing but instead source in part from third-party manufacturers in Asia—this is a solution that offers us tremendous peace of mind. That’s because Richard Geiss GmbH can adapt its own degreasing process at its Offingen facility much more quickly to new—and, above all, constantly changing—component challenges than we can in Fridolfing,” explains Mühlberger.

At Rosenberger, the process optimization of individual part production and degreasing also has an impact on procurement. “We have tightened our purchasing regulations. For example, suppliers must now document which oils were used to manufacture their components. Only then do they receive approval from us,” explains Mühlberger.

Plant manufacturer Vapic was, of course, also fully involved in the optimization process and made several changes to the plant’s technical systems. “In the original configuration, some components were still very PER-oriented. That was intentional, because we wanted to keep the door open for a hybrid solution. However, we quickly realized that it would be better to completely bypass the absorber and the activated carbon unit,” said Mühlberger. Vapic also made adjustments to the water separator and the storage tanks.

What everyone involved has learned from the project: If the degreasing process is to work with hydrocarbons and alcohol, the system must be 100 percent tailored to this solution from the very beginning. “Otherwise, it simply doesn’t make sense,” explains Michel Lubinsky-Fischer, Sales Division Manager for Surface and Textile Cleaning at Richard Geiss GmbH. The project at Rosenberger is a prime example of outstanding teamwork and a partnership in action. “We have impressively demonstrated that we truly live out the four pillars of our RG4Chemicals brand—namely, supply, support, disposal, and the promise of quality—in our day-to-day operations,” says Lubinsky-Fischer.

Thanks to the experience that Rosenberger, Geiss, and Vapic have gained together from the current plant project, a new sense of confidence has developed. The oldest PER plant in Fridolfing is scheduled to be replaced in 2027. “We’ve gained so much process expertise that we’ll also be operating the new system with Geiss’s IsocleanN RG 59,” says Markus Obermayer.

The expertise in optimal surface treatment at Rosenberger Hochfrequenztechnik GmbH & Co. KG has grown over decades. Helmut Mühlberger has been with the company for 40 years now and headed the Surface Technology division for over 15 years before taking on the role of group leader for individual-part production. Rosenberger in Fridolfing has relied on Richard Geiss’s high-quality products, expertise, and comprehensive service for over 15 years. “Back then, we completely switched from raw materials to distillates in our cleaning process and deliberately chose Richard Geiss GmbH as our regional partner, who has truly provided us with all-around service ever since,” says Mühlberger. The professionals at Geiss handle the supply of distillates, the disposal of waste materials, regular laboratory analyses, and employee training. (OM-7/26)