At the Fraunhofer Umsicht environmental, safety and energy technology institute in Oberhausen, Germany, researchers have developed an antibacterial solution that they claim "gives no chance for bacteria," as it involves highly efficient impregnation with nano silver particles into the outer surface of molded parts.
The key to the process is pumping liquid carbon dioxide into a high-pressure container holding the parts to be treated.
Researchers say scratches do not affect the impregnated surface. High-grade plastic parts and lifestyle products like cellphone housings can be treated with custom colors, additives and UV stabilizers well under the plastic's melt temperature and without using aggressive solvents.
The institute is also one of 13 partners in a 3.95 million euro Ecoplast project supported by the EU that is studying the use of biomass-based composites in automotive engineering. Auto parts supplier Grupo Antolin-Irausa SA of Madrid is a partner.
The collaboration has sought to improve the material properties of polylactide acid and polyhydroxybutyrate, using plant-based and mineral fillers and reinforcements. It also is focused on creating a protein-based bioplastic matrix to meet automotive standard requirements.
Fraunhofer Umsicht scientists are working on surface modification of plant-based natural fibers to make them more compatible with PLA. The aim is to achieve a fiber coating that not only provides homogenization in surface chemistry and topography, but optimizes transfer of forces from the polymer matrix to the fibers when the plastic part is subjected to mechanical load.
