Patent GB-1386242-A (GB)
Title: Apparatus for manufacturing foam laminates
IPC: B29C44/30
Filed: 1971-07-08
Abstract: 1386242 Apparatus for producing foam cored laminates IMPERIAL CHEMICAL INDUSTRIES Ltd 27 June 1972 [8 July 1971] 32096/71 Heading B5N An apparatus for manufacturing a laminate comprising a rigid layer of foam, e.g. foamed polyurethane, polystyrene, polyvinylidene chloride, urea-formaldehyde resin, epoxy resin or polyethylene confined between two outer sheets of facing material, comprises means for applying a liquid mixture of foam-forming ingredients to at least one of the sheets of facing material and conveying means for causing the two sheets of facing material to move parallel to one another while formation and setting of the foam are taking place, the conveying means comprising a lower driven conveyer 1 extending the length of the apparatus and three successive upper conveyers each mounted independently of the other two, the first upper conveyer 10 co-operating with the lower driven conveyer to form a laminating zone A wherein the two sheets with the expanding foam therebetween are positioned in the desired relationship to one another, the second upper conveyer 16 co-operating with the lower driven conveyer to form a holding zone B wherein the laminated assembly arriving from the laminating zone is held in a nominal thickness dimension for a period of time sufficiently long to achieve dimensional stability in the main body of the foam, and a third upper conveyer 20 co-operating with the lower driven conveyer to form a traction zone C to exert sufficient pressure on the cured foam laminate arriving from the holding zone to move it outward out of the apparatus while simultaneously drawing fresh facing material and foam into and through the laminating and holding zones. In the apparatus shown, the lower driven conveyer 1 comprises a series of slats, e.g. of metal, riding on tracks, one of which is a guiding track to ensure that the slats can only travel in one direction. The individual slats may be rubber covered; alternatively, a continuous rubber belt 6 may be fitted loosely on and around the whole slat conveyer. The first upper conveyer may be a nip roller 10 which is non-driven and may optionally be heated or cooled. The upper conveyer 16 of the holding zone which is non-driven and the upper conveyer 20 of the traction zone which may optionally be driven, may each comprise a slat conveyer, the upper conveyer 20 riding freely upon the lower conveyer 1 under the control of a floating linkage 21 to ensure that no lateral forces are applied, the floating linkage 21 including a vertical link terminating at an air cylinder 22 piped to a three-position pneumatic valve, the three positions of the valve being such that the upper conveyer 20 may be set to ride on the lower conveyer 1 under its own weight, under more than its own weight or completely supported by the valve. The nip roller 10 may be replaced either by a plurality of rollers or by a conveyer belt. In a preferred embodiment (Fig. 5, not shown), a continuous belt is run around both the holding and traction zones. When profiled facing sheets are used, appropriately profiled supports are run into the apparatus together with the facing sheets.