Patent GB-1202701-A (GB)
Title: Prefabricated building panel
Inventor: POPE KENNETH W
IPC: B29C44/32
Filed: 1966-09-02
Abstract: 1,202,701. Laminates; moulding building panels. KALCO HOLDINGS Ltd. 1 Sept., 1967 [2 Sept., 1966], No. 39434/66. Headings B5A and B5N. [Also in Division B6] A building panel comprises a rigid layer of cellular plastics, spaced facing elements bonded to one face of the layer, and granular material adhered to and embedded in the cellular plastics between the facing elements. The celullar layer may be a rigid foamed plastics layer, e.g. of polyurethane and the facing elements may be a brick, stone, ceramic, wood, concrete or plastics tile. The particulate material may be sand. A rigid backing sheet may be adhered to the face opposite the face to which the facing elements are bonded. By using facing elements resembling bricks, the building panel can be given the appearance of a conventional brick wall with mortar between adjacent bricks. The finished panels can be fastened directly to the building frame-work or siding by means of an adhesive, fasteners, or a combination of both. Sands of different colours can be used for the simulated mortar joint, and in addition ground stone, minerals, ceramics of pulverized brick or glass can also be utilized. Examples of suitable formulations for the production of rigid polyurethane foam are described. The panels can be made by pasting face down in the desired relation bricks on the bottom of a mould having the desired shape. The bottom of the mould can be provided with locating bars to space the facing elements into the desired pattern. Sand is then placed in the spaces between the facing elements and the polyurethane foam ingredients are brought together for the foaming reaction and the mixture is spread over the back of the facing elements using, for example, a twin-component gun. The mould is then covered with a plywood backing sheet or left uncovered and the reactants permitted to complete the foaming reaction. Alternatively the panels can be produced continuously. As shown in Fig. 5 rows 28 of brick facing elements 14 are positioned in spaced and staggered relationship on conveyer 26 by a feeding means (Fig. 6, not shown), sand 29 is distributed over the tops of the brick facing elements 14 by dispenser 30, rotary brush 32 removes the sand from the tops of the facing elements 14. Polyurethane is distributed over the rows of facing elements 14 by guns 34, and the conveyer 26 then carries the panel components into a curing oven 36 in which the polyurethane is heated to facilitate curing and foaming. Prior to entry into the curing oven 36 a second conveyer 37 contacts the top of the polyurethane 35 and exerts downward pressure on it. The feed conveyer may be of a traversing type which reciprocates laterally to join the operation to stagger the rows of brick and the feed conveyer brings the brick facing elements to a rotating shaft to which are secured a plurality of cams for loading the brick facing elements on the main belt 26 (Figs. 3, 4, 6, not shown). Locating pins are fixed on the conveyer 26 in positions such that facing elements in contact with the locating pins are disposed in a desired spaced relationship. Roll brushes preferably set at about 45 degrees to the path of travel of the conveyer 26 are provided to urge the bricks into contact with the locating pins. Located along each side of the conveyer 26 are regularly spaced closure blocks 64 (Fig. 3, not shown) spaced so as to be opposite alternate rows of brick and adapted to reciprocate laterally between an inward position and an outer position so that the panels are formed with alternate rows having projecting bricks which extend beyond the adjacent bricks at a distance equal to one half their length. The closure blocks have an extension which closes the space between adjacent closure blocks thereby forming the sides of a continuous mould. The closure blocks are pushed into place immediately after the sand has been distributed and brushed by the rollers 32. A dispensing rack may be provided to hold pre-cut plywood sheets and to dispense them one at a time so that they are placed in proper relation to the brick facing elements 14 before passing through the companion belt which exerts downward pressure during curing. The companion belt is provided with separating bars at intervals corresponding to the desired panel width and are adapted to come down into the inter-panel spaces (Fig. 3, not shown). The polyurethane core may be double the desired thickness and a layer such as plywood, roll roofing or plaster board is then bonded to the upper surface of the polyurethane layer and the panels then sliced centrally between the two faces to provide two building panels.