We are laying up a cfrp part that is on a scale of complexity around a 5 ( 1 to 10 scale ). The laminate has 4 layers of 12K, biaxial, stitched graphite cloth. First pull i noticed there was bridging on a tight inside corner of the mold. Do you think it is possible, out of autoclave, to get no bridging with this single lay up schedule? We used a paddle to push the layers down but the paddle wasn’t very stiff.
As always it would depend on the flexibility of your fabric and the pressures used. It’s impossible to say without a good look at the geometry and fabric though. However maybe try pressure intensifiers or a stiffer paddle like you mentioned.
Could you replicate the geometry of the (presumably) female tool on a male paddle? i.e., instead of the paddle being the shape of the stick, have the paddle the male version of the geometry you are trying to get the cloth into? Could help squeeze the fabric into the tight geometry better
4 layers of 12K biax should be able to be pushed enough to get tighly into corners. If all else fails, design a relief cut in the fabric at that area, in the 2nd and 3rd layer.
What he said…