Poly-Lactic Acid-Bagasse Based Bio-Composite for Additive Manufacturing

Abstract

Beer bagasse is a residue waste produced in great amounts; nevertheless, it is still underestimated in the industry. The aim of this paper is to develop an innovative and efficient methodology to recycle the beer bagasse by producing Poly-lactic acid(PLA)-based bio-composites, in the forms of pellets and filaments, to be used in additive manufacturing processes. To assess the suitability of beer bagasse for extrusion-based 3D printing techniques, it was, firstly, physically and chemically characterized. Then, it was added in combination with different kinds of plasticizers to PLA to make bio-composites, analyzing their thermal and physical properties. The results prove the great potential of bagasse, evidencing its printability. Both composites’ pellets and filaments were used in two different 3D printing machines and the mechanical properties of the 3D-printed models were evaluated as a function of the composition and the kind of technology used. All the used plasticizers improved processability and the polymer–bagasse interface. Compared to neat PLA, no changes in thermal properties were detected, but a lowering of the mechanical properties of the 3D-printed composites compared to the neat polymers was observed. Finally, a comparison between the efficiency of the two 3D printing techniques to be used with the bio-based composites was performed.

Bio-Composite Filaments Based on Poly(Lactic Acid) and Cocoa Bean Shell Waste for Fused Filament Fabrication (FFF): Production, Characterization and 3D Printing

“…Furthermore, the melting process seems to be particularly influenced by the presence of the CBSW filler, which leads to the development of a double melt peak (T m and T m1 ) in composite biofilaments, which is absent in 100PLA (Figure 6B). Similar behaviour and the presence of the double melting peak were observed by the authors in biocomposites based on polylactic acid and olive wood waste, indicating a different behaviour during the phase transition between the polymer and the organic filler [35].…”

“…The phenomenon appears to be attributable not only to a different diameter of the particles in the mixture (PLA approximately 500 µm measured by SEM and CBSW 5 µm to 1 mm diameter measured by SEM), but also to a different chemical nature that creates poor interfacial adhesion. This occurrence is already known in the literature for various PLA-based composites and waste fillers with different polarities and may indicate the possibility in the future of using plasticizer agents that improve the compatibility and adhesiveness of the different substances [ 35 ].…”