3D Reproduction of a Snow Crystal by Stereolithography

Abstract

A new method was proposed for replicating snow crystals that uses light-curing resin containing no harmful substances, as the replicating material, and the 3D reproduction of a snow crystal by stereolithography was conducted. It was found that a UV light irradiation density of at least 0.6 mW/cm2 was required to complete the light-hardening reaction within 15 min when polyene/polythiol resin (NOA81) was used as the light-curing resin. When the atmospheric temperature was 0 °C, the maximum temperature rise due to the light-hardening reaction was 4.2 °C at an irradiation density of 1.0 mW/cm2. This suggests that the initial temperature of the light-curing resin must be approximately -5 °C to prevent the snow crystal from melting when an irradiation density of 1.0 mW/cm2 is applied at an atmospheric temperature of below 0 °C. This replication method has sufficient accuracy to reconstruct the 3D shape of a snow crystal. The 3D reproduction of a snow crystal by stereolithography was conducted by transforming the CSV-formatted 3D profile height data to STL-formatted CAD data.

Keywords

• snow crystal
• 3d reproduction
• light-curing resin
• irradiation density
• light-hardening reaction
• replication accuracy
• stereolithography