Nano-silica modification of UV-curable EVA resin for additive manufacturing

Due to layer by layer printing, the interlayer adhesion of resin used in extrusion-based additive manufacturing (AM) is poor, while thermal curing affects the accuracy of the resin. Therefore, methods of photo-curing and nanomodification were used in this work to improve the adhesion between layers and the overall performance of AM resins. Specifically, ethylene-vinyl acetate (EVA) copolymer with dual curing agent of benzophenone/triallyl isocyanurate (BP/TAIC) and nano-silica (NS) were introduced. The results of light transmittance, scanning electron microscopy and gel content test showed that BP/TAIC with NS were proved to be able to improve the curing process of EVA. The filling of a small amount of NS did not act as ultraviolet light barrier, but instead improved the photo-curing of the resin and reduced the amount of agents. UV curing also improved the adhesion between layers of EVA resin. The tensile strength was 7.1% higher than that of EVA/NS/BT without curing. At the same time, due to good interface bonding and dispersion, the thermal conductivity of resin improved from 0.212 W/m*k to 0.252 W/m*k. A 16.1% raise in tensile strength and a 10.0% increase in the volume resistivity were demonstrated for the 3.0 wt% NS. Furthermore, this resin is potential to be used in AM. KEYWORDS additive manufacturing, ethylene-vinyl acetate, nano-silica, photo-curing, property
1 | INTRODUCTION Additive manufacturing (AM) often referred to as 3D printing. Unlike traditional manufacturing processes, materials were stacked layer by layer to fabricate three-dimensional parts during AM. [1,2] There [...]