Reducing the surface deviation of stereolithography using in‐process techniques

TLDR

Stereolithography surface roughness has been mathematically modeled, but the print‑through effect that smooths down‑facing planes only works over limited angles, necessitating additional smoothing methods. The study aims to employ the surface‑roughness model as a design tool to determine optimal build orientations and plan post‑process finishing. The authors propose generating a meniscus between layers as an in‑process technique to reduce surface roughness and lessen manual finishing. Model development revealed that various in‑process attributes of stereolithography influence surface deviation.

Abstract

Builds on previous research by the authors to establish a mathematical representation of the surface roughness of stereolithography (SL) parts. It is the intention of the research to use this modelling technique as a design tool for defining optimum build orientation and planning post‐process finishing operations. During the development of this model, a number of in‐process attributes inherent in SL were seen to affect surface deviation. Most notably the phenomenon known as “print‐through” on down‐facing planes produces a build orientation envelope of very smooth surfaces. Although capable of providing low roughness over some 50°, print‐through smoothing cannot easily be extended to other angles, hence complementary processes for surface smoothing must be developed. Discusses a number of possible solutions, showing how the generation of a meniscus between layers can prove beneficial in reducing SL surface roughness, hence reducing the need for lengthy manual finishing operations.