Apparatus for the continuous fabrication of cellular products of a

Abstract

A method for the continuous fabrication of blankets or sheets of expanded phenolic resin displaying a hard skin on each of their sides, according to which a mixture, comprising in particular a resole resin, a blowing agent and a hardening catalyst is placed on an essentially flat surface of a moving conveyor, is completely expanded, and is conformed eventually between two parallel surfaces entrained in the same direction, the second surface being located above and substantially parallel to and able to move at the same speed as the moving surface, characterized in that, in a first stage, after having been distributed at the surrounding temperature and in the liquid state along the whole width of the surface of the transport component, in such a way so as to comprise a blanket of expandable liquid mixture essentially uniform in thickness, the expandable mixture is conveyed in the open air towards the conformation surfaces while being submitted to a heating so that it expands, the degree of heating and the length of the path in the open air being chosen in a way that the upper skin loses its stickiness before the complete expansion of the mixture and that after the complete expansion, the obtained expanded mass reaches an immediate hardening state, the upper skin remaining supple and unsticky; and then the expanded mass is formed by the exertion of pressure on its free side at the time of entry between the conformation surfaces, thus reducing the thickness of the mass to its definitive value; and finally the hardening of the resin is completed by maintaining the pressure and the heat during the passage between the conformation surfaces.