Abstract: A structural panel that may be suitable for use in building construction, the panel may have a core bonding to first and second skins, the core may be a first foam layer, a membrane, and a second foam layer, the membrane and at least one skin configured to be suitable to retain fasteners, the foam layers having low density, good shear strength and stiffness, the skins and the membrane having higher density and good strength.

Abstract: A structural panel for use in building construction, which may include a first skin having a first face, a second skin having a first face spaced apart from the first skin first face, a reinforcing member having a first surface fixed to the first skin first face and a second surface fixed to the second skin first face, a first foam piece having a first surface fixed to the first skin first face, a second surface fixed to the second skin first face, and a third surface facing a third surface of the reinforcing member, and a second foam piece having a first surface fixed to the first skin first face, a second surface fixed to the second skin first face, and a third surface facing a fourth surface of the reinforcing member.

Abstract: A method and apparatus for making thin panels having a urethane core and hinges for interconnecting them. A frame is secured to a support bed, and a sheet of paper is placed inside the frame into overlying relation to the bed. Plural board members are then placed inside the frame so that they overlie the peripheral borders of the sheet of paper and so that they are held in position by the frame. Tubular members are positioned in bores formed in the board members so that they extend into the area bounded by the extrusion members, and the innermost end of the tubular members are taped over to prevent foam intrusion. A second sheet of paper is then placed over the frame and a rigid top plate is lowered into overlying relation to the second sheet of paper so that the frame is sandwiched between the bed and the top plate. Foam is then injected into the cavity defined by the board members and the sheets of paper through a port formed in a board member.