Abstract: A polyurethane foam is produced by mixing foam forming chemicals with the mixing being effected to produce an unfoamed liquid mixture and then feeding the unfoamed liquid mixture into an open-topped trough in which the liquid mixture remains for a dwell time during which an exothermic and gas-forming reaction occurs and the liquid begins to foam and for a partially foamed froth. The volume of the open-topped trough and the dwell time of the foam forming chemicals in the trough are adjusted by tilting the trough. The partially foamed froth is discharged across a curved lip portion at the top of the open-topped trough on to a surface on which the foamed froth is allowed to further react and form a solid polyurethane foam material. The curved lip portion is shaped to minimize shear forces and stresses in the foam and ensure smooth overflow of the foamed froth at different tilt angles.

Abstract: A flexible polyurethane foam is made by reacting an isocyanate with a polyol in the presence of a foam-forming agent and a fire-retardant additive. The fire-retardant additive comprises melamine and this is used in conjunction with a polyol which is of the polymer-modified polyol kind, i.e. a polyol containing a polymeric substance such as a dispersed alkanolamine/isocyanate polyaddition product.

Abstract: A flexible polyurethane foam is made by reacting an isocyanate with a polyol in the presence of a foam-forming agent and a fire-retardant additive. The fire-retardant additive comprises melamine and this is used in conjunction with a polyol which is of the polymer-modified polyol kind, i.e. a polyol containing a polymeric substance such as a dispersed alkanolamine/isocyanate polyaddition product.

Abstract: A flexible polyurethane foam is made by reacting an isocyanate with a polyol in the presence of a foam-forming agent and a fire-retardant additive. The fire-retardant additive comprises melamine and this is used in conjunction with a polyol which is of the polymer-modified polyol kind, i.e. a polyol containing a polymeric substance such as a dispersed alkanolamine/isocyanate polyaddition product.

Abstract: A polyurethane foam is produced using acetone as an auxiliary blowing agent. A polyol, an isocyanate, water, acetone and a catalyst for catalyzing the formation of polyurethane are mixed to produce an unfoamed liquid mixture, which is then retained in bulk form, preferably in an open-topped reaction vessel, for a dwell time during which an exothermic reaction occurs and the liquid foams. Finally, the foaming liquid is spread on to a surface on which it is allowed to expand and form a solid polyurethane foam material. Significant reductions in the amount of auxiliary blowing agent can be achieved, as compared with conventional formulations using methylene or CFC's as auxiliary blowing agents.

Abstract: A foam material, such as a polyurethane foam, is formed by mixing a polymer forming material with a blowing agent and two catalysts, one catalyst being provided to catalyze polymer formation and the other catalyst being provided to catalyze blowing. An auxiliary blowing agent in the form of a vaporizable substance, such as methylene chloride, is also incorporated. In one embodiment, the mixed components are maintained in a reaction vessel prior to application of same to a surface on which the foam is allowed to expand. In a further embodiment, in the case where the foam is polyurethane foam and the vaporizable substance is methylene chloride, the mixed components are maintained in a reaction vessel prior to application of same to a surface on which the foam is allowed to expand and the methylene chloride is used in an amount in excess of 12% of the weight of the polyurethane-forming material.