| That is all I got, sorry. Presumably the holes spacing is 40-50mm, but I guess it could be multiples of this. No idea if the tow is continuous or trimmed some distance from the hole. Also no idea what weight of tow, or whether it was carbon or glass. Pretty hopeless really, but gives you plenty to experiment with. ;-)

How do they know they got H100 like performance in some ways?

I imagine just the infusion columns of epoxy will add a lot of perceived compressive strength to the foam.

Imagining the loading paths;
Either (?) the tow spreads the loads to a larger foam area, Which seems good, or the load goes down the column to the other side, which might put a delaminating force on the back side? Which seems not good?
Or not, as the two sides cannot spread or separate, and the load will just engage the stiffness of the far side too, doubling the effect of surface stiffing tow, up to the point the column or the surface enhancement fails?
So the load, in this case, acts like an I beam? Where the web is the epoxy (and tow?) column?

Does anyone have a better visualization?

If the above is anywhere near correct, this might point to turning a cheap foam into a cheap honeycomb like thing. Drill the holes closer, perhaps bigger. Offset the hole rows to get a honey comb/hex pattern. Stitch between each hole and all 6 adjacent to get good surface tow coverage. (Just a typical zigzag stitch). Infuse.

The foam only needs to last through the infusion. Ultimate weight savings by solvent flushing the foam out. Will be weak vs racking(?) forces, I imagine. Leave the foam for better racking strength. Or make the holes big enough to get some angle in the stitches.

5 axis cnc angle drill the holes? Machine?? Stitch on the angle? Sounds expensive. I am stopping this line of thought.

The added tow could also be a weight saving gimmick. Perhaps even money saving too as one uses less epoxy in the column. But too much, and it literally clogs the hole. #

A sewing machine like mechanism could stitch the holes with tow relatively quick. I imagine the stitch selected could add tow in different areas, like column vs surface

A low strength foam might compress too much under full vac, and bend or loosen the vertical tow while compressed. But if said tow is encased in epoxy, does that matter much? 25 psi xps or 40 psi polyiso might be good enough.

Something like H45 might be a great material, in that it does not warp under full vac, so the tow stays straight, if straight/taunt tow columns matter..

I am thinking the tow being vertical does not matter. It is probably the surface tow that adds the most to the foam properties anyway, as it is more properly infused with correct epoxy ratios, and stiffens the surface and transfers loading to larger surface areas and additional columns. A raw epoxy column has to have a large compressive strength

So, my Gedankenexperiment seems to say, just add tow to the surface. Perhaps the holes dont matter?

Sorry for the long rant. Please review brutally.