Method for manufacturing a composite and a wind turbine blade

1. A method of manufacturing a composite, comprising:

laying a first fibre mat onto an inner surface of a mould;

applying suction between the inner surface of the mould and the first fibre mat such that the first fiber mat flattens against the inner surface of the mould;

laying a second fibre mat over the first fibre mat;

covering the second fibre mat with a vacuum bag after said applying suction between the inner surface of the mould and the first fiber mat;

introducing vacuum between the vacuum bag and the mould;

injecting resin under vacuum between the vacuum bag and the mould;

letting the resin set; and

removing the mould, wherein a medium which is suitable to distribute vacuum is placed between the inner surface of the mould and the first fibre mat, and is used for applying the suction between the inner surface of the mould and the first fibre mat, and is connected to a vacuum pump for applying the suction.

2. The method as claimed in claim 1 , wherein the medium which is suitable to distribute vacuum is placed between the inner surface of the mould and the first fibre mat and between two subsequent further fibre mats, and wherein the two subsequent further fibre mats also flatten against the inner surface of the mould.

3. The method as claimed in claim 2 , wherein a core material is placed between the two subsequent fibre mats.

4. The method as claimed in claim 1 , wherein the second fibre mat is covered with a mould core which is covered by the vacuum bag such that the vacuum bag is placed on the second fibre mat.

5. The method as claimed in claim 1 , wherein the medium which is suitable to distribute vacuum is impregnated by resin.

6. The method as claimed in claim 2 , wherein the medium which is suitable to distribute vacuum is impregnated by resin.

7. The method as claimed in claim 1 , wherein a layer of material having a lower air permeability than the fibre mats is placed on top of the second fibre mat.

8. The method as claimed in claim 7 , wherein the material having a lower air permeability than the fibre mats is suitable for lamination.

9. A method of manufacturing a wind turbine blade, comprising:

laying one or more first fibre mats onto a concave inner surface of each of a lower part and of an upper part of a mould;

applying suction between the inner surfaces of the mould parts and the one or more first fibre mats;

laying a second fibre mat over the one or more first fibre mats in the lower part and the upper part of the mould, the second fibre mats comprising a layer of material having a lower air permeability than respective outermost ones of the one or more first fibre mats;

covering the second fibre mats with a vacuum bag such that the vacuum bags are placed on the second fibre mats;

covering the second fibre mat laying in the lower part of the mould with a mould core;

placing the upper part of the mould on top of the lower part of the mould such that the mould is closed;

introducing vacuum between the vacuum bags and the mould;

injecting resin under vacuum between the vacuum bags and the mould;

letting the resin set; and

removing the mould and the mould core.

10. The method as claimed in claim 9 , wherein the upper part of the mould has a longitudinal axis, and wherein the upper part is turned around the longitudinal axis before placing the upper part on top of the lower part of the mould.

11. The method as claimed in claim 9 , wherein a medium which is suitable to distribute vacuum is placed between an inner surface of the upper part of the mould and a respective one of the first fibre mats.

12. The method as claimed in claim 9 , wherein a medium which is suitable to distribute vacuum is placed between the inner surface of the lower part of the mould and a respective one of the first fibre mats.

13. The method as claimed in claim 9 , wherein a medium which is suitable to distribute vacuum is placed between two subsequent fibre mats.

14. The method as claimed in claim 11 , wherein the medium which is suitable to distribute vacuum is impregnated by resin.

15. The method as claimed in claim 13 , wherein a core material is placed between subsequent fibre mats.

16. The method as claimed in claim 9 , wherein at least one shear web is placed onto the second fibre mat laying in the lower part of the mould.

17. The method as claimed in claim 9 , wherein at least one fibre mat which is placed in the lower part of the mould overlaps with at least one fibre mat which is placed in the upper part of the mould.

18. The method as claimed in claim 9 , wherein at least one fibre mat which is placed in the upper part of the mould overlaps with at least one fibre mat which is placed in the lower part of the mould.

19. The method as claimed in claim 17 , wherein a biaxial fibre mat is used as the fibre mat which overlaps with at least one fibre mat of the upper part of the mould.

20. The method as claimed in claim 18 , wherein a biaxial fibre mat is used as the fibre mat which overlaps with at least one fibre mat of the lower part of the mould.