Investigation on the Effect of Process Parameters to Improve the Optical Transparency of 3D Printed PLA Parts

This research aims to improve the optical transparency of polylactic acid (PLA) parts fabricated through fused filament fabrication (FFF) processes, enabling bright and consistent illumination patterns. The study employs a design of experiments (DOE)-based analytical modeling technique to investigate the illumination properties of optically transparent FFF-printed parts. A custom sensing setup incorporating a standard light-dependent resistor (LDR) was used to measure the optical transparency of the printed components. By analyzing printing parameters through detailed experimental and analytical modeling, the research achieved high transparency levels and consistent illumination patterns in PLA parts. Insignificant factors and their interaction effects were systematically eliminated from the regression model through analysis of variance (ANOVA), identifying significant parameters such as layer height, build orientation, infill density, and the number of shells. Visual examination of illuminated parts, achieved by lighting them with a light-emitting diode (LED), demonstrated bright and consistent patterns. The analytical model generated can be used to predict optical transparency in terms of analog to digital (ADC) values and shows R square of 89.43%. The ADC values obtained from LDR for PLA printed parts range from 986.00 to 990.64. This comprehensive investigation not only highlights the potential of FFF for creating optically transparent decorative objects but also paves the way for future research into advanced applications of additively manufactured transparent parts.