Production of heat insulating products

1,136,811. Paperboard. FOSECO TRADINGAG. 7 Sept., 1966 [14 Sept., 1965], No. 39212/65. Headings D2A and D2B. A method for the production of continuous lengths of refractory heatinsulating material comprises feeding an aqueous slurry of a particulate refractory material-e.g. sand-, an organic fibrous material-e.g. wood pulp or paper pulp-, a binder, and optionally asbestos fibres onto a water-permeable moving belt 2 having laterally disposed of the belt, deckle members, and compressing the layer of slurry thereupon by means of at least one other moving belt 5. The belt 2 may be of rubber and have a gauze sheet superimposed thereon. The deckle members may be formed by an upstanding rim at each side of the belt 2 or by stationary members in sliding contact with the edges of the belt. A left and right hand threaded Archmedean screw 41 and/or doctor 45 may be used to spread the slurry from tank 1 evenly over the belt. Rollers 7 of belts 5 and 6 are adjustably mounted. Rubber rolls 11, 12 may smooth the formed web which may then be fed directly in an oven, or cut into lengths and contoured before being passed into an oven.