Hi folks,
Im looking to make a few flat sheets with carbon and some sort of of core material (PVC, Nomex, honeycomb etc) and I’m needing some advice from anyone who has done this??
I’m looking to autoclave these parts and I’m wondering if i should make the sheets first then bond the core in on a secondary cure, or is there a better way? I did a sample piece earlier where i cured a composite panel with 1x layer of 200gsm 3k twill, 2 x 0 degrees UD, PVC core, 2x 0 degrees UD and then a finish twill. My idea was to cure a lower panel with carbon and core, then i was going to produce a sheet with material only, place on the top and bond together. What happened is the finish consisted of lots of dimples which look like they are positioned at the same points that there was holes in the core. This makes me think that maybe i applied too much pressure? I had the parts in a 4bar? apart from the evenly spaced dimples the finish was pinhole free. The other issue was the laminate developed a large bow in the part. Could this be due to the lack of 90 degree layers?
Anyway, I am open to any advice as i would like to make sandwich panels. Core and process advice would be hugely appreciated!