Additive Manufacturing Utilizing Stock Ultraviolet Curable Silicone

Extrude and Cure Additive Manufacturing (ECAM) is a method that enables 3D printing (3DP) of common thermoset materials. Ultraviolet (UV)-curable silicone is an example of a thermoset material with a large number of industrial and medical applications. 3D printed silicone prototype parts are obtained using a custom high pressure ram, valve, and UV exposure system. This paper will address issues with printing stock UV curable silicone such as electrostatic repulsion, in-nozzle curing, and extrudate slumping. One solution that addresses two issues is adding carbon black (CB) to the mixture to reduce electrostatic repulsion while also inhibiting UV cure depth, hence preventing material from curing in the nozzle. Evidence shows that too much carbon black can be detrimental to the structural stiffness of the resulting part.