Abstract: Light wood, also known as Balsa, is a tropical fast-growing tree of kapok family native to South America and the West Indian Ocean Islands. It has the characteristics of small density, stable volume and structure and not easy to deform. Through years of application verification, its performance has been fully recognized by the wind power blade industry. In recent years, with the continuous decline of the cost of wind turbine generator, the price of wind power continues to decline. As a key component accounting for 25%~30% of the cost of the whole machine, it provides support for reducing industry cost by cooperating with the development of large blades of high-power wind turbine. To meet the needs of structural design, light wood with a thickness of more than 30 mm, which was rarely used in the past, has become a common choice in the structure of large wind turbine blades. In the actual manufacturing process of wind power blades, there are many defects such as bubbles, delamination caused by this kind of light wood, which seriously affect the manufacturing quality of wind power blades. In order to improve this problem, the defect occurrence mechanism, light wood material characteristics and influence are analyzed, and the solution of destroying the adhesion of bound water and reducing the total content of residual water is locked.

Key words: composites, wind turbine blade, light wood, core material, defect