Total volatile organic compound emission evaluation and control for stereolithography additive manufacturing process

Abstract

Additive manufacturing has gained rapidly increasing public interest as it has shown to be a viable and promising alternative to traditional manufacturing processes. Since a great number of additive manufacturing processes are used in indoor environments without proper emission control, there is an urgent need to assess and prevent any potentially harmful effects on the environment and human health. The stereolithography process utilizes photosensitive liquid resins, which might cause hazardous gaseous emissions due to the volatilization process as well as additive manufacturing production activities. Current studies fail to theoretically evaluate these emissions and propose efficient emission control approaches. This paper aims to advance the state-of-the-art on emission evaluation for stereolithography-based additive manufacturing by establishing an analytic model for the total volatile organic compound emissions. The proposed analytical model is experimentally validated. In addition, the measured emission levels are significantly higher than the reported values in literature as well as the recommended emission standards. Therefore, two emission control strategies are proposed as follows: (1) the adoption of Titanium Dioxide photo catalytic oxidation method, and (2) the employment of activated Carbon absorption approach. Compared to current commercial technology, the two proposed strategies are tested and lead to 44.15% and 71.06% reductions in the average total volatile organic compound concentration, and 62.74% and 68.54% in the total volatile organic compound caused by additive manufacturing activities, respectively.