| abstract |
1375948 Thermally insulating panel BALSA ECUADOR LUMBER CORP 3 Feb 1972 [10 Feb 1971 10 Nov 1971] 5112/72 Heading B5N [Also in Divisions F2 and F4] A thermal insulation panel comprises at least one facing sheet bonded to at least one layer formed from balsa wood beams and another insulating material of similar thermal conductivity substantially filling the spaces between the beams. Several layers L 1 , L 2 , L 3 (Fig. 2), may be superposed and the axes of the beams in one layer may be displaced from the axes of the beams in an adjacent layer. The other material may be in the form of slabs or bags of expanded material: foamed polyurethane, polystyrene, P.V.C. or glass, expanded mineral insulation, e.g. perlite or vermiculite, fibreboard, fibreglass insulation, rockwool, hairfelt and cork being referred to. The facing sheet, which may form the inner surface of a liquid storage tank may be formed of plywood, aluminium, high pressure phenolic polymers, steel, a flexible open mesh screen of glass fibres, a polyurethane film or paper and may be bonded to the core with an epoxy or urethane adhesive. The slabs may be pre-compressed before assembly so that as the panels are cooled gaps do not form between the beams and the slabs. The gaps between the edges of adjacent panels which may be dove-tailed or mitred may be filled with flexible insulation. In Fig. 9, the panel is composed of fire-retardant plywood facing sheets 38, 44 and a core of two layers of balsa beams B and insulating slabs F separated by a plywood sheet 40, the upper and lower parts being offset as shown to provide for interfitting. |