Material extrusion additive manufacturing of short glass fiber-reinforced epoxy composites via time-dependent rheological control

Abstract

Extrusion-based additive manufacturing of thermosets and short fiber-reinforced thermoset composites is a challenging task and remains, despite recent advances, unable to fully leverage the entire design freedom offered by state-of-the-art technology due to low viscosity and solidification way of ink. This study introduces an enhanced direct ink writing (DIW) technique for effectively printing thermoset resins and corresponding short glass fiber-reinforced composites, achieved without adding any rheological modifiers and using ultraviolet (UV) curing. The proposed method utilizes time-dependent rheological control to enhance the ink's properties, offering a cost-effective and experimentally simplified approach. Experimental results suggest that the raster angle had no substantial effect on the mechanical properties, or in other words, the printed specimens behave like an isotropic material. To achieve maximum tensile properties, the ink parameters, such as fiber weight fraction, mixing time, and mixing speed, were optimized using the Taguchi design of experiment. The results showed a strong correlation between predicted and observed values, confirming the efficacy of the approach. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.