New research project: Liquid silicone injection molding with additively manufactured, resin-based tool inserts
In February 2025, the SKZ Plastics Center and the UNIpace (Polymer Application Center) at the University of Kassel launched a pioneering research project entitled “ADDmold for LSR”. The aim of this ambitious project is to enable the injection molding of liquid silicone rubber (LSR) using additively manufactured tool inserts for the first time. The process thus offers significant advantages in the production of prototypes, small series and specialized applications.
Additively manufactured tool insert and the component manufactured with it (Image source: Christian Deubel, SKZ)
Additive manufacturing, also known as 3D printing, has long been an integral part of industrial production and shows its strengths particularly in the production of complex, individualized components. Additively manufactured resin-based tool inserts can offer considerable advantages, particularly in the product development of injection molded components or in small series production. Compared to conventional metal tools, not only can production times be significantly shortened, but manufacturing costs can also be drastically reduced. This efficient approach makes it possible to economically produce small series of components from the desired target material and to flexibly design product development processes with multiple iteration loops.
Until now, however, the use of additively manufactured tool inserts in injection molding was limited to thermoplastic processing. This led to a considerable restriction of application possibilities, as liquid silicones in particular, which are indispensable in many branches of industry such as medical technology, the automotive sector or electrical engineering, could not be processed without conventional metal tools. This is where the “ADDmold for LSR” research project comes in: By combining additive manufacturing and liquid silicone processing, the aim is to create a completely new way of producing silicone components. The advantages of cost-effective small-batch production and shorter product development cycles should also be available for LSR types in the future.
This innovation opens up far-reaching potential for industrial users in particular, especially small and medium-sized enterprises (SMEs). By using additively manufactured tool inserts for LSR, SMEs can react more flexibly to customer requests, reduce development times and adapt more quickly to changing market requirements. This helps to strengthen the competitiveness of these companies in the long term. It also creates new opportunities for customized product solutions that were previously not feasible for economic or technical reasons.
Ralf-Urs Giesen, Managing Director of UNIpace at the University of Kassel, emphasizes the importance of this research project: “This completely new approach to silicone processing will enable existing companies that already work with silicones to benefit significantly from the advantages of additive manufacturing. The ability to create tools quickly and cost-effectively will significantly increase the innovative strength of this industry.”
Alexander Schulmann, Research Associate Additive Manufacturing at SKZ, adds: “With this project, we are further expanding our expertise in the field of additively manufactured tools. We have already gained extensive experience with thermoplastics and now see great potential in revolutionizing the processing of liquid silicone in the same way.”
Interested companies have the opportunity to actively participate in the research project. The project partners invite companies to join the project committee free of charge. By participating, companies can not only benefit from the research results at an early stage, but also contribute their own requirements and use cases to the development.
For further information or to get in touch directly, please contact the SKZ and the University of Kassel.
