Method of making a composite panel of a foam material

Abstract

A method of making a foam product including the steps of reacting an isocyanate component with a polyol component and foaming with a foaming agent to form a self-supporting intermediate foam material. The isocyanate component is present in excess of a stoichiometric quantity needed to react with the polyol component. The self-supporting intermediate foam material is then contacted with water and the self-supporting, intermediate foam material is heated to form a foam product, the water reacting with the remaining unreacted isocyanate component. The self-supporting, intermediate foam material formed by the first foaming step is rigid or semi-rigid at room temperature but it can be softened by heating to enable it to be used for deep draw molding in a successive cure molding process without cracking, splitting or being destroyed. Once the self-supporting, intermediate foam material is contacted with water or steam in the final cure molding process to react the remaining isocyanate component, the material becomes a finally cured, rigid or semi-rigid foam material which will not soften on heating. The self-supporting, intermediate foam material can be laminated with facing materials or reinforced with glass fiber--non-woven cloth or the like to give a composite panel which exhibits stiffness, heat insulation, acoustic insulation, moisture resistance and is light in weight so that it can be used for a molded ceiling or door panel in an automobile or a partition or screen for interior use.