BIO-SMC: Development of a Sheet Molding Compound (SMC) on the basis of renewable raw materials
Sponsor: LORENZ Kunststofftechnik GmbH
Sheet Molding Compound (SMC) was developed in the 1960s and initially enabled the production of glass fiber reinforced polymer composites (GFRPC) in mass scale production. Currently, approximately 20% of all glass fibers produced in Europe are processed to SMC. Nowadays, both material and process are well established for the production of semi-structural components in various applications from electrical devices and automotive components to construction industry. Increasingly strict ecological and economical requirements for construction materials are forcing further development of SMC materials regarding lighter, mechanically more resilient and also bio-based alternatives. A conventional standard SMC semi-finished product for electrical applications, based on unsaturated polyester-resin, consists of approx. 15 -25 wt.-% unsaturated polyester-resin with anti-shrinkage additives, approx. 7 Gew.-% application-specific additives (e.g.: internal release agents, coloring agents), approx. 40 wt.-% mineral fillers (e.g. calcium carbonate) and approx. 20 – 35 wt.-% chopped glass fibers with a length of approx. 25,4 mm.
Within the project BioSMC conventional resin systems, reinforcing fibers and filler materials should be replaced by bio-based and renewable raw materials. The aim is to develop a bio-based SMC semi-finished product, that can be processed with conventional processing parameters and state of the art processing equipment. Furthermore, the bio-based SMC should show a density reduction about 20 %, compared to a conventional SMC, while maintaining same mechanical properties.