Moisture diffusion coefficients determination of furan bonded sands and water based foundry coatings

摘要

Moisture content in furan bonded sand and water based coatings can be one of the main causes for gas related defects in large cast iron parts. Moisture diffusion coefficients for these materials are needed to precisely predict the possible moisture levels in foundry moulds. In this study, we first compare two different experimental methods that can be used to determine moisture diffusion coefficients. Then, we determine diffusion coefficients for water based coatings and for different types of furan binders and we investigate the effects of compaction, dust levels and temperature. Finally, we provide an example on how it is possible to apply this knowledge to estimate moisture variation in a sand mould during production.