Fabrication of SS 316L particle-infilled PLA composite filaments from cast-off bi-material extrudates for 3D printing applications.

Abstract

The identification of recyclable resources are extremely important to balance the growing demand for polymer composite 3D printing and sustainable manufacturing. In the present study, SS 316L powder particle infused PLA filaments are fabricated by deriving PLA from discarded bi-material extrudates, adopting solvent mixing methodology. The matrix reclaimability, composite feedstock fabrication, extrudability and printability are investigated by increasing the solid loading from 10 - 40 wt%. Outcomes of the FTIR for 'PLA gel' and 'extrudate dissolved gel' are identical and confirms the matrix reclaimability. Essential characterization studies like XRD, TGA, and DSC are carried out for composite feedstock. The reinforcement dispersion in composites is quantified with the help of microscopy results. The melt rheological studies reveal that all the extruded filaments exhibit shear thinning over a shear rate of 50 s^-1 and are compatible with 3D printing. The tensile strength is improved by 22.4% after adding 10 wt% reinforcement to the recycled PLA. The economical benefits are evaluated by comparing the composite filament fabrication with the pure PLA matrix. The study concludes recommending viscous modifiers to improve filament processability and increase loading capacity beyond 40 wt% for indirect metal additive manufacturing.