Ambient relative humidity effects on mechanical properties of FDM 3D printed PLA components

Abstract

Abstract In this study, poly(lactic acid) samples were printed by using the fused deposition method whereas ambient relative humidity conditions and filling percentages varied. The effects of the relative humidity on the mechanical and thermal properties of the samples were investigated. It was observed that the mechanical properties of the samples decreased as the relative humidity increased and that specimens with low filling percentages were affected more by relative humidity. Differential scanning calorimetry results showed that the glass transition temperature, melting point, and crystallization temperature were inversely correlated with relative humidity. The surface structure was also negatively affected by the relative humidity, and the intensity and size of the voids increased as the relative humidity increased. In addition, this study recommends that the manufacture of materials with a 3D printer be conducted at low humidity to achieve high flexural strength and modulus.