Effect of Layer Thickness on the Tensile and Impact Behaviour of SLA-Printed Parts

Abstract: This paper systematically investigates the influence of layer thickness on the mechanical properties of the SLA printed parts. Specimens were fabricated with four different layer thicknesses, namely 25, 50, 75, and 100 microns, and evaluated for tensile and impact performance. Results showed that as layer thickness increases, mechanical properties significantly deteriorate. The tensile strength values had decreased from 57.5 MPa at 25 microns to 38.2 MPa at 100 microns, while the impact strength declined from 9.5 J/mm² to 5.5 J/mm² over that same range. The major causes for this mechanical property degradation are the poor adhesion between the layers, increased surface roughness, and imperfections introduced by the formation of thicker layers. On the contrary, with the thinner layers, the approach tends to produce layers having stronger interlayer bonding, reduced defect percentages, and higher structural integrity; therefore, superior mechanical performance. The investigation can furnish helpful guidelines for optimizing the thickness of layers in SLA printing so as to balance mechanical properties with production efficiency while catering to the need of high-precision applications requiring superior mechanical strength and excellent impact resistance