Multi-material textile waste as biomass feedstock: using fused filament fabrication to investigate optimal stirrer geometries in non-Newtonian media

Processing of blended polyester-cotton waste is difficult using traditional methods. Biocatalytic separation of the fractions via enzymatic hydrolysis of the cellulose fraction offers an alternative approach, resulting in processable polyester and glucose solution as a secondary product. The scale up to intermediate scale (60 l) processing of these shear-thinning non-Newtonian suspensions has been reported, but further investigations of flow properties and optimization of stirrer geometries are required. The aim of this work is the development of optimized stirrer geometries and dimensions via fused-filament fabrication. Mixing times were compared by a computer-assisted optical method and via speed torque assessment.