Effects of Environmental Temperature and Humidity on the Geometry and Strength of Polycarbonate Specimens Prepared by Fused Filament Fabrication

Published

October 3, 2020

Author(s)

Lichen Fang, Yan Yishu, Ojaswi Agarwal, shengyu Yao, Jonathan Seppala, Sung Hoon Kang

Abstract

It is widely known that the printing quality of fused filament fabrication (FFF) is heavily affected by environmental temperature and humidity, as the case of warping and porosity. However, there is little understanding about the quantitative relations between environmental conditions and geometry and mechanical properties of printed parts. In this study, we have systematically investigated those relations using bisphenol A polycarbonate as a model material system. For the environmental temperature, in-situ infrared imaging analysis revealed the presence of up to 5.4 °C/mm thermal gradient when printing using an open-chamber printer and a heated build plate. For the environmental humidity, analysis of X-ray micro-computed tomography (micro-CT) scans showed up to 11.7 % porosity, which is brought by polymer water content absorbed from environmental moisture. Meanwhile, tensile tests showed the mechanical performance loss associated with those defects, but surprisingly the transverse direction ductility may increase at higher porosity. Furthermore, the experimental results are combined with analytical and parametrical studies to elucidate quantitative relations between environmental conditions and printing quality. Based on the results, quantitative guidelines for estimation of printing quality based on environmental conditions are provided, which would also help users to obtain desired printing results with a better understanding of the effects of environmental conditions.

Citation

Materials

Pub Type

Journals

Keywords

fused filament fabrication, environmental temperature, humidity, X-ray micro-computed tomography, porosity, mechanical properties

Citation

Fang, L. , Yishu, Y. , Agarwal, O. , Yao, S. , Seppala, J. and Kang, S. (2020), Effects of Environmental Temperature and Humidity on the Geometry and Strength of Polycarbonate Specimens Prepared by Fused Filament Fabrication, Materials (Accessed May 10, 2024)