Laminas are the layers of matrix (e.g. glass) and/or other materials. Then there is the bonding element (glue, resin, whatever).
is when the layers become lose due to bonding element's (e.g. resin) failure or to the lamina's failure.
Delamination may result either from overpowering the bond (e.g. in solid GR laminates) or else from failure of the bonded element (e.g. in sandwiches the core
In solid laminates the failure most often happens when the timing was off - unlikely in modern vacuum single-injection techniques.
over poly productions/repairs are likely to delaminate if flexed too much.
A properly balanced, one-shot, poly or epoxy
GR laminate is very, very unlikely to delaminate