Method for producing polyurethane sandwich molded parts

A process for producing polyurethane sandwich moldings comprising at least one core layer and at least one reinforcing fiber layer, wherein

• i. at least one reinforcing fiber layer is applied onto a core layer and a moisture-curing polyurethane adhesive is applied to the at least one reinforcing fiber layer,
• ii. the part from i. is placed into a mold and pressed in the mold and the moisture-curing polyurethane adhesive is cured, wherein the mold defines edges of the cured polyurethane adhesive, wherein the polyurethane adhesive is sufficiently free-flowing in the mold such that no open edges or corners are formed, and
• iii. the molding from ii. is removed from the mold and optionally subjected to further operations,
• wherein the moisture-curing polyurethane adhesive has a viscosity of 6000 mPas to 50000 mPas, measured at 25° C. according to DIN 53018,
• wherein the moisture-curing polyurethane adhesive comprises at least 80% by weight, based on a total weight of the moisture-curing polyurethane adhesive, of isocyanate-terminated prepolymer which is obtainable by mixing a stoichiometric excess of aromatic isocyanate with polymeric compounds having at least two isocyanate-reactive groups and optionally compounds having only one isocyanate-reactive group and optionally chain extenders and/or crosslinking agents and
• the moisture-curing polyurethane adhesive is applied before or after application of the at least one reinforcing fiber layer onto the core layer and for the curing the moisture-curing polyurethane adhesive is brought into contact with water or with a solution comprising water.