The advancement of Digital Light Processing (DLP) in 3D printing has catalysed
the production of high-quality parts characterized by their high resolution and swift
manufacturing turnaround. Despite its popularity, the detailed effects of specific printing
parameters on material properties have not been fully outlined. This study investigated how
layer height, exposure time, and bottom exposure time influence the tensile strength and
surface roughness of photopolymer resin parts produced via DLP. Utilizing a Taguchi
method 9v9 experimental design, the contribution of each parameter to the variance in
mechanical properties were explored. The statistical analysis reveals that layer height
significantly dictates the surface roughness, contributing to 52.97% of the total variance.
Simultaneously, bottom exposure time and layer height substantially influence tensile
strength, accounting for 29.64% and 19.00% of the variance, respectively. Exposure time,
however, has a minimal impact, contributing just 1.36% to tensile strength and showing
negligible effects on surface roughness. Optimization efforts identified a layer height of 0.05
mm and bottom exposure time of 15 seconds as optimal, markedly improving tensile strength
and surface finish. Scanning electron microscope (SEM) analysis correlates these optimized
parameters with crack morphology, offering microstructural evidence that parts printed with
optimal settings demonstrate a more resistant structure to tensile forces, as indicated by the
presence of rougher, more tortuous crack patterns on stronger samples. The optimal
parameters serve as a benchmark for producing parts with superior mechanical strength and
surface integrity, thereby fulfilling the increasing industrial demand for robust, 3D-printed
components
