> Volume fractions are used when mixing the two (or more) EPOXY components.
Sometimes, by some people...
> Mass fractions are used when determining fiber/mixed epoxy ratios.
I guess we disagree on the volume fraction stuff then.
Strange world, there are quite some differences between the two sides of the pond. Americans measure fuel consumption in miles per gallon, we use liters per 100km. Most epoxies are weighted here, rarely mixed by volume. And for fiber content comparisons of laminates we use volume fractions.
> Again - how would one determine the volume of woven cloth?
Density of the raw material is known. Yarn diameter is known. Weight per lenght is known (1 tex = 1g/km), grammage (weight per area) is known. Thickness of the cloth and the laminate is known. More than enough data to come up with a volume ratio, don't you think?