Low-solvent process for rubber coating on metal from Huehoco

Since its foundation as a cold strip coating plant in 1893, Huehoco GmbH has developed into a leading specialist for the finishing of metal products. Its core business is the coating of metal strips in various dimensions with organic coating materials and rubber. These rubber-coated strips have sealing, noise and vibration-damping properties and are used in the automotive industry as engine gearbox seals and damping plates, among other things. "Conventional rubber coating requires large quantities of solvents. In order to reduce the environmentally harmful use of solvents, we set ourselves the goal of implementing a process that for the first time almost completely dispenses with solvents in rubber coating," explains Dr. Ulrich Irle, Consultant, Huehoco Group Holding GmbH & Co.KG. The technical innovation of the process developed by Huehoco is that the rubber mixture is brought to the desired coating thickness directly via an extruder in several polished rollers arranged one on top of the other. Immediately afterwards, the mixture is applied to the surface of the metal strip pre-coated with adhesion promoter, dried and vulcanized. Coatings from 100 micrometers to 2,000 micrometers can be produced using this innovative process.

"Compared to the state of the art, the new coating process saves up to 96% in solvents and 86% in film every year - a benefit for our company and the environment," says Dr. Ulrich Irle. In addition to material savings, the process also reduces electricity consumption by up to 57 percent and gas consumption by up to 94 percent. With an annual capacity of 654 tons, this results in an annual reduction in CO2 emissions of around 1,917 tons - a saving of 86 percent. "The low-solvent coating process is a game changer for the entire industry," says Dr. Ulrich Irle. "Thanks to our innovation, we are working on new products that were previously out of focus - for example in the fields of electromobility and hydrogen technology." In 2016, the company used the support of the Efficiency Agency NRW (Effizienz-Agentur NRW - EFA) to apply for funding under the Environmental Innovation Program of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV). The project was funded in February 2017 with around EUR 2.03 million from the BMUV environmental innovation program. Following approval, the EFA was commissioned to prepare the final report. The project was completed in 2023. Huehoco GmbH invested a total of around EUR 14 million in the project.