Foam cored grp sandwich panels - with grp bridge profiles at frequent intervals for greater strength, for boat hulls

摘要

Sandwich panels with GRP outer layers and an intermediate layer of bonded synthetic foam, where the structure incorporates long bridging elements of resin impregnated glass which are bonded to both facing panels by faces linked by rounded corners. Pref. the reinforcing panels are shaped like troughs with lips having a combined surface area similar to the area of the base of the trough, and the structures are assembled by lining a mould with one resin impregnated facing layer, over-laying this at intervals with shaped strips of core foam, laying up bridge elements over the foam strips either as preshaped profiles or by direct spray-up, then laying up the rest of the foam between the bridging elements and finally laying on the other sandwich panel. Strengthening effect can be sufficient to allow satisfactory use of polyurethane foams weighing 40 kg/m3 instead of PVC foams fo 100 kg/m3.