Additive Manufacturing of Tough Silicone Via Large-Scale, High-Viscosity Vat Photopolymerization

Abstract

In this work, a large-scale, high-viscosity vat photopolymerization additive manufacturing system is designed and fabricated to print 3D structures as large as 370 × 300 × 370 mm3 out of high-viscosity, low-reactivity elastomeric resins. A detailed overview is presented of the printer's design and capabilities, including a resin processing sub-system that stores and spreads high-viscosity resin; a roll-to-roll variable tensioning system to mitigate the separation forces after printing each layer; and a light patterning system that generates high-intensity light patterns across an area of 370 × 300 mm2 with a resolution of 3840 × 4320 pixels. The ability to print with both high-viscosity and low-reactivity resins and resins that require high-intensity light enables additive manufacturing of new classes of materials that could not be printed previously using vat photopolymerization techniques. These materials include highly reinforced silica nanoparticle composites, high-molecular-weight polymers such as silicones and acrylate or methacrylate resins, and low-reactivity resins such as photocurable platinum-catalyzed liquid silicone rubber.