The quality of biocomposites depends on fibres moisture content during manufacture as it affects microstructure, mechanical properties and internal mechanical states. Managing moisture content during manufacturing and service life is therefore essential for high-performance parts. This study investigates key manufacturing steps of flax-epoxy biocomposites produced by Vacuum Assisted Resin Transfer Moulding (VARTM), focusing on the moisture content throughout the process, including vacuum assisted compaction, curing (including post-cure) and service life under temperature and relative humidity (RH) loads. During compaction, no desorption occurs at 20°C for preforms of 30x30 cm 2 . However, a decrease of sample size or an increase in temperature can induce moisture desorption regardless of pressure (from 12 % to 7 % at 50°C, 72 h). During cure (24 h at 20°C), even though a slight decrease in moisture content is observed (0.7 %), post-curing does not affect this desorption, regardless of its duration or temperature until 60°C. Finally, for both flax fibres and cured biocomposite, temperature only affects the equilibrium moisture content during sorption above 70 % RH (−17 % at 90 % RH from 20°C to 60°C). These results indicate that moisture content of flax-epoxy composites remains largely unchanged throughout ambient-temperature VARTM process when pre-conditioning and post-cure do not exceed 70 % RH and 60°C, respectively.
benjamin et al. (Wed,) studied this question.