Abstract: A contoured structural laminate formed of thin facings bonded to an end-grain balsa wood core. The laminate is produced by first bonding a liner of end-grain balsa to each facing to create front and rear plies. The exposed surfaces of the liners are then wet coated with a bonding solution, and the two plies with their coated liners in face-to-face relation are placed in a forming press which causes the front ply to assume a concave-like formation and the rear ply a complementary convex-like formation. During forming, the wet interface of the liners affords slip freedom. When the bonding agent dries and cures in the press, the plies are permanently laminated together to form the desired contoured structure.

Abstract: A structural sandwich laminate constituted by thin skins, such as aluminum or fiber-reinforced plastic sheets bonded to the faces of a core formed by an array of wood strips having a periodic wave formation. The wavy strips in the array are out of phase with each other and are bonded together at their contiguous troughs and peaks to define an open-celled expanded wood structure whereby the laminate, though light-weight, has high strength.

Abstract: A structural sandwich laminate formed of thin facings, such as aluminum or fiberglass sheets, bonded to a core panel. The core panel is formed of end-grain balsa wood having an array of holes punched therein, the holes having their centers on the apexes of a diamond, thereby making possible a high concentration of holes with an adequate separation therebetween to define a reticulated balsa core of high strength and exceptionally light weight.