Impact of different weight fractions of silica nanoparticles on the surface finish, rheological, and mechanical properties of photopolymer 3D printed nanocomposites using UV lasers

This study utilized a 3D printer that employed the photopolymer extrusion (PPE) technique with ultraviolet (UV) lasers to solidify a liquid-photosensitive polymer material. The research focused on studying fumed silica nanoparticles reinforced fillers with PPE, aiming for improved surface finish while maintaining desired rheological and mechanical properties for printing and application requirements. Various silica filler concentrations were examined during the experiments. It was noted that composite mixtures with fillers exceeding 10% exhibited significantly increased viscosity, rendering them unsuitable for extrusion in 3D printing applications. Additionally, it was observed that these mixtures displayed an increase in viscosity over time (aging), indicating a limited shelf-life. Non-contact profilometer results revealed enhanced values of roughness average (Ra) and root mean square average (Rq) for surface roughness in a 9% fumed silica mixture. This concentration resulted in superior surface properties compared to others, leading to improved print quality and higher strength overall; however, higher concentrations negatively impacted the bending properties of the printed samples.