Laser Sintering of Pine/Polylatic Acid Composites

A new powder feedstock composed of sustainable and degradable biomass composite material was proposed for laser sintering technology in this research. This biomass mixture, abbreviated P-PLA, is made up of mechanically mixed polylactic acid (PLA) powder and pine powder. The proper processing parameters were determined based on the component thermal behavior and laser sintering testing: processing temperature 130-135°C, laser power 20-24 W, scan spacing 0.1-0.2 mm, scan speed 1.6-2.2 m/s and layer thickness 0.2mm. Laser-sintered P-PLA parts exhibited much better mechanical properties compared with pine/polyethersulfone copolyester (PCoPES) wood-plastic composite, with tensile strength 34-200% higher and flexural strength 92- 246% higher than values for laser-sintered P-CoPES. Results reveal that pine powder loading can reduce the shrinkage and deformation of laser-sintered P-PLA parts. Shrinkage decreased from 4% to 0.31-2.27% in the XY plane and from 3.25% to 0.13-2.25% in the Z direction.