Sustainable 3D printed poly (lactic acid) (PLA)/Hazelnut shell powder bio composites for design applications

In the context of seeking sustainable solutions for developing innovative materials and products by an efficient use of natural resources and recycling waste, with an increasing focus on circular economy and mitigating environmental impact, the presents research aims to use biomass and agricultural residues as raw materials for bio composite production. Specifically, valorizing European hazelnut waste presents a unique opportunity to devise innovative formulations for 3D printing, leveraging both the mechanical properties and aesthetic appeal of lignocellulosic bio composites. In detail, this work aimed at the investigation of new poly(lactic acid) (PLA)/Hazelnut Shell Powder formulations for 3D printing design applications exploiting the woody aesthetic effect of these bio composites. A pellet 3D printer was used to bypass the filament production. Three different Hazelnut Shell Powder content (from 10 up to 30 wt%) were investigated and a design of experiment was carried out to generate response surfaces able to identify the best printing conditions to optimize flexural, tensile and impact properties. Finally, the effect of three different raster angles (0°, ±45° and 90°) on the mechanical properties was investigated. The best configuration was: 220 °C of nozzle temperature, 25 mm/s of printing speed and ±45° of raster angle. With this configuration, prototypes of ornamental pots, jewellery and home furniture were produced as demonstrators.