If you think about it, interlaminar tension (trying to pull layers apart) is always a matrix faliure. Even if you have only a single ply, the only way to "pull" on that ply in that orientation is to adhere a pad on either side of the sheet and try to pull them apart. So it doesn't really matter if you have one layer of cloth or a hundred, or whether they are woven or uni... the matrix will fail either somewhere in the middle of a stack, or you'll pull the resin off of the top or bottom of the stack. In any case, it is always the matrix failing. The only reason you would expect a slight increase in interlaminar tension strength with a single layer is because of the presence of small non-wetted areas in the middle of laminate stacks - without those the properties would be the same. We handle this by applying a statistical knockdown on the properties that is appropriate for the number of plies used, flow properties of the resin used, and competence of the manufacturing method.
As for interlaminar shear, that again is a matrix dominated failure because no fiberer run perpendicular to the stack, whether for many plies or for one. And again, if you have a single layer you are testing the matrix on the top or bottom instead of somewhere in the middle of the stack, and the same knockdown considerations apply due to the same dry spot problems. If constructed and tested appropriately, uni stacks should develop close to the same interlaminar shear strength as a woven stack, but in practice in-plane shear failures often occur first and obscure good data.
Thick composites... man, some amazing stuff can be done. The most common approach for large scale stuff (and for high quality smaller stuff too) is a vacuum assisted resin transfer method (VARTM, but goes by many other names). This is a process where a vacuum is pulled on the stack of cloth dry, and resin is pulled through tubes from a reservoir by the vacuum, pulled through the composite stack, and then into another reservoir. It's sort of like injecting glue into something under pressure, but instead you are pulling glue into the composite under vacuum (and at the same time consolidating the part). Some really big stuff can be done this way. I've designed single panels sixty feet long and sixty feet wide that are many inches thick.
As for interlaminar shear, that again is a matrix dominated failure because no fiberer run perpendicular to the stack, whether for many plies or for one. And again, if you have a single layer you are testing the matrix on the top or bottom instead of somewhere in the middle of the stack, and the same knockdown considerations apply due to the same dry spot problems. If constructed and tested appropriately, uni stacks should develop close to the same interlaminar shear strength as a woven stack, but in practice in-plane shear failures often occur first and obscure good data.
Thick composites... man, some amazing stuff can be done. The most common approach for large scale stuff (and for high quality smaller stuff too) is a vacuum assisted resin transfer method (VARTM, but goes by many other names). This is a process where a vacuum is pulled on the stack of cloth dry, and resin is pulled through tubes from a reservoir by the vacuum, pulled through the composite stack, and then into another reservoir. It's sort of like injecting glue into something under pressure, but instead you are pulling glue into the composite under vacuum (and at the same time consolidating the part). Some really big stuff can be done this way. I've designed single panels sixty feet long and sixty feet wide that are many inches thick.