Number of layers

General Composites Discussions Composites Talk
#1

I know it all depends on exactly what you’re making and such, but here’s my example.

I’ve run out of 2x2 3k right now but I have some 2x2 12k laying around. About 3 yards or so.

I tested 4 layers of the 12k stuff doing a piece that’s flat, and has a slight angle bend to it in one section. The part is very small and is just a cover for something but has basically all flat sections.

I laid this part up like this:
First layer 0/90
Second layer 45/45
Third layer 45/45
Fourth layer 0/90.

All warp directions/dominate zero’s were mirrored so nothing was flipped, and no piece of fabric was rotated more than 45 degrees counter clockwise.

My question is can this be done with just 2 layers of 12k 2x2? This stuff is strong and is probably equal to 4x layers of 3k that I was using before.

My main concern is warping

#2

Warping is always related to heat, using epoxies.
If you are able to manage the CTE while moulding, you should be ok because you use balanced fabrics.
What will change for shure is the behaviour of the panel under mechanical loads.
But on a simple cover I can’t see the problem.