Abstract: In the vacuum infusion process of preparing wind turbine blades,the unidirectional permeability of Vacuum Assisted Process （VAP） membrane can continuously pump out the air inside the vacuum bag membrane,prevent the resin from being pumped out,and solve the process problem of not being infused through due to the existence of air bubbles locally in the blade molding and infusion. The air permeability performance of different models of VAP membrane was tested,and the microstructure of VAP membrane was observed by optical microscope. The test results show that the air permeability of VAP membrane is related to the ambient pressure difference in molding and infusion and the number of its holes.

Key words: wind turbine blades, VAP membrane, air permeability