Abstract: There is provided a method of pultrusion using multiple resins. In the method a continuous interior reinforcement layer and a continuous exterior reinforcement layer are supplied and the interior reinforcement layer is infused with a first resin and then combined with the exterior reinforcement layer to form a pultrusion reinforcement structure. The pultrusion reinforcement structure passes into an infusion die where a second resin infuses the exterior reinforcement layer, and then passes into a curing die to cure the resins and form a composite article. The second resin comprises an aliphatic isocyanate polyurethane resin with a greater concentration of aliphatic isocyanate than is present in the first resin to give the composite article superior UV resistance. A pultruded composite article produced by the pultrusion method is also provided.

Abstract: There is provided a multi-layered composite article having an inner core of a first composite material and one or more than one outer layers of a second composite material, the second composite material comprising an aliphatic isocyanate polyurethane overlaying the inner core. A method of manufacturing such a composite article is also provided. The method comprises providing a core comprising a reinforcement impregnated with a first resin; mixing an aliphatic isocyanate component and a polyol component to produce a reaction mixture; impregnating a second reinforcement with the reaction mixture to produce an impregnated reinforcement; applying the impregnated reinforcement over an outside surface of the core; and allowing the reaction mixture to set to produce a composite article with one or more than one outer layers of aliphatic isocyanate composite material.

Abstract: A high solids black liquor which has solids content of at least 65% by weight of liquor is mixed with a viscosity reducing additive prior to firing in a chemical recovery furnace. The additive is an admixed compound consisting of monoethylene glycol, diethylene glycol and triethylene glycol.