FlexSiliconAdditive – Flexible additive manufacturing of 2K silicone material systems

Due to their chemical and mechanical properties, silicones are increasingly being used as moulded parts in industry, pharmaceuticals, the food sector, and medical engineering. Their flexible options for production and processing mean that silicone elastomers can be used to produce complex workpieces precisely and cheaply. Parts made from silicone are extremely robust from a chemical and mechanical perspective and have a high degree of thermal resistance, making them suitable for a wide range of applications. For example, sealing and fixing elements are also manufactured from silicone elastomers, as are industrial prototypes and precision moulded parts. Due to its lack of toxicity and ease of cleaning, together with its thermal resistance, silicone rubber is also a frequently used material in the food and kitchen industry.

In recent years, there has been a clear production trend towards specific components in low quantities. In prototype construction and special machine construction, for example, there is often only a need for a single workpiece made from silicone. However, conventional manufacturing processes are not economically viable for this. Additive manufacturing (3D printing) is ideal for small quantities and complex shapes. The market share of additively manufactured components in small-series production is steadily increasing. More and more types of materials are being considered for additive manufacturing. In addition to conventional plastics (thermoplastics, resins) and metals, it is now possible to produce flexible components from (thermoplastic) elastomers using 3D printing. The additive manufacturing of components using the silicone rubber described above is of particular interest.

Silicones are typically processed by casting with liquid or paste-like raw materials. Silicones used in industry and medical engineering are made from multi-component base materials that are either hardened by a chemical reaction or cured by UV light or heat. Self-curing silicones, as they are known from sanitary engineering, are not generally used for industrial or medical engineering applications. A preliminary project has shown that materials belonging to the group of “liquid silicone rubbers” (LSR) have the greatest potential for 3D printing. Thanks to their adaptable material properties, they are versatile and can be processed as liquids or pastes.

Therefore, a system for the additive manufacturing of LSR silicone building components is being developed within the framework of the FlexSiliconAdditive project. The novelty over existing silicone printer systems is the use of production-quality silicones from conventional injection moulding. There is therefore no need to develop new special-purpose 3D printing silicones. The additively manufactured prototypes also already have the material properties of series components. The newly developed system is intended, in particular, for use in development departments and for material development and small-series production.

Project leader: Prof. Michael Koch, Dr.-Ing. Dipl.-Wirt.-Ing.

Researcher: Robin Löffler, M.Sc.

Contributors: KL TECHNIK GmbH & Co. KG, Rapid Prototyping

Funded by: Zentrales Innovationsprogramm Mittelstand (ZIM)

Dates: 1 May 2022 – 31 July 2024