Method for manufacturing a fiber reinforced polymer composite beam, particularly a spar beam for a wind turbine rotor blade

Abstract

A method for producing a hollow composite structure, such as a spar beam for a wind turbine blade, includes placing a membrane within a mold tool, the membrane being permeable to air and impermeable to resin. A mandrel is placed within the mold tool, the mandrel enclosed in an air tight layer that includes a vent. Fiber reinforcement material is placed around the mandrel within the mold tool and the membrane is sealed at least partly around the fiber reinforcement material and mandrel. The mold tool is closed with the vent line from the mandrel extending through the sealed membrane to outside of the mold tool. A vacuum is drawn in the mold tool while the mandrel is vented to outside of the mold tool, and while the vacuum is being drawn, resin is infused into the mold tool around the mandrel such that the resin is drawn towards the membrane.

Dependencies are inferred from the claim text.