In additive manufacturing Fused Filament Fabrication (FFF) is outstanding since common thermoplastics can be used. Thus, this method can meet the industry’s demands of producing complex designs in limited series with familiar materials. To fully exploit the technique’s potential, new printing materials have to be developed, as currently only a few types of materials (mostly PLA and ABS) are commercially available for FFF. Therefore, the Chair of Polymer Processing is systematically developing novel materials for their use in FFF.
For example, specially filled polyolefins with low shrinkage coefficients and good dimensional stabilities are investigated. These materials provide several advantages compared to existing filament types, such as higher impact strength and better temperature stability. Moreover, wood fibre reinforced materials for FFF are under investigation. The biggest challenge with these materials is an accurate production of perfectly round filaments, as the additional fibres prevent elongation and therefore a proper calibration. Another field of research are highly filled materials, wherein the polymer acts as the binder system. After printing, the parts are debound in a solvent and sintered in a furnace similar to powder injection moulded parts. Currently, compounds filled with highest possible amounts of metal and ceramic powders are being developed. So far, compounds with a maximum of 91 wt.% (55 vol.%) of stain-less steel are still processable.
For the systematic development of new materials for FFF, mechanical, flow, adhesion and shrinkage properties of materials have been characterised, compared and linked to printability.