grp basics - micro strand length

General Composites Discussions Engineering Talk
#1

A micro strand starts out as full length, and handling breaks them? Thus a tow is made up of “short” micro strands, which slide past each other unless there is resin bonding them together?

A resin-rich laminate is weaker cause there is more resin between the micro strands, which cracks before the glass fibres do?

How much weaker is a dry tow versus a resined one? Theoretically they would be the same if it weren’t for broken micro strands?

Tks,

#2

I’ll let an engineer handle the bulk of this question.
However, I would not go as far to say that handling breaks all the fibers. A few here and there, but I think 1% is a good #.
Yes, the more resin you have, the weaker the laminate is due to the crack propagation, and the inability to have the fibers take the load. There is a point where too LITTLE resin does not bind the fibers together.