ASHCROFT, I.A. ... at al, 2012. Environmental ageing of epoxy-based stereolithography parts. Part 1: moisture transport. Plastics, Rubber and Composites: Macromolecular Engineering, 41 (3), pp. 120-128
It has been shown that current epoxy-based stereolithography materials are highly
hygroscopic . However, the diffusion of moisture into these materials and the effect this
has on the mechanical performance of manufactured parts has not been thoroughly
investigated to date. The first part of this paper will discuss the transport of moisture into
representative stereolithography materials and the second part of the paper will describe the
effect of the absorbed moisture on mechanical performance. Moisture transport in three
different epoxy-based stereolithography materials has been investigated using mass uptake
experiments. The results show that anomalous (non-Fickian) diffusion occurs to varying
degrees in all three materials, the characteristic uptake appearing to be pseudo-Fickian.
Anomalous uptake models based on dual-sorption , diffusion-relaxation  and a dual-
Fickian model were all shown to provide an excellent fit to the data. The effects of relative
humidity and sample thickness are also investigated in the paper.