moisture and bio ethanol swelling restraint in Polyamide 6

Thread by Tom Christiansen on 21 Feb 2011 at 15:30:02 
From the CheFEM section I understood that glass fibre reinforcement can restrain chemically driven expansion (so the reduction in expansions is more than proportional than the volume of fibres)

I found that dry Polyamide 6 has an E modulus of 3.1 GPa, with 3% wt% Water E becomes 1.1 GPa, and with wt% 6% Water it decreases to 0.7 GPa. In presence of bio Ethanol (the opposite side in our application), the figures won't be much better. Nevertheless, our application works quite well in real-life. Can this be due to the swelling restraint as predicted by the CheFEM simulation software. Could we quantify this effect for a given loading of glass fibres?

Tom Christiansen