Patent ID: 8007624

Claim:
A method of manufacturing a wind turbine blade comprising composite materials, comprising: selecting an outer mould part; selecting an inner mould part, wherein at least a substantial part of the surface of the inner mould part comprises a compressible layer being covered by an airtight membrane; evacuating the compressible layer, thus causing the compressible layer to become compressed; positioning, after the evacuating, materials to be bonded in a mould cavity between the outer mould part and the inner mould part; wherein after positioning, the outer mould part encloses the inner mold part; evacuating the mould cavity; and bonding the materials; wherein the inner mould part is selected such that a force of expansion of the compressible layer provides sufficient pressure for the bonding; and wherein the inner mould part is selected such that it exceeds the hollow space provided by the outer mould part when the compressible layer is not compressed.