Patent ID: 9580598
Date: 2017-02-28
CPC Classifications: B29C,B29L,C08G,C08J,C08L,Y02P

Claim:
1. A process for producing a fiber-reinforced polyurethane composite article by vacuum infusion molding, comprising: (a) degassing components comprising an isocyanate component and an isocyanate-reactive component, wherein: (b) combining the de-gassed components (1) and (2) to obtain a polyurethane-forming reaction mixture having a viscosity at 25° C. of less than 600 mPa·s for at least 30 minutes, a gel time at ambient temperature of greater than 60 minutes and a water content of less than 0.06% by weight, based on total system weight, wherein components (1) and (2) are combined in amounts such that the NCO Index is from 99 to 110 to form a polyurethane having sufficient green strength to be de-molded at ambient temperature in no greater than 6 hours; (c) placing a fibrous reinforcing material in a vacuum chamber arranged to form a wind turbine blade; (d) drawing down the pressure within the vacuum chamber to thereby push the reaction mixture into the vacuum chamber and into the fibrous reinforcing material; and (e) curing the reaction mixture to form a composite of the fibrous reinforcing material infused with the cured reaction mixture that is in the form of a wind turbine blade.