WIND TURBINE BLADE

• US 20110097211A1
• Filed: 03/30/2009
• Published: 04/28/2011
• Est. Priority Date: 03/28/2008
• Status: Abandoned Application

• Current Assignee: Paul Rudling
• Original Assignee: Blade Dynamics Limited (General Electric Company)
• Inventors: Rudling, Paul
• Application Number:
  US12/935,236
• Publication Number:
  US 20110097211A1
• Time in Patent Office: Days
• US Class Current: 416/229.00R
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2307/41 Opaque
• CPC Class Codes: B32B 2307/514 Oriented
• CPC Class Codes: B32B 2307/536 Hardness
• CPC Class Codes: B32B 2307/558 Impact strength, toughness
• CPC Class Codes: B32B 2307/58 Cuttability
• CPC Class Codes: B32B 2307/712 Weather resistant
• CPC Class Codes: B32B 2307/72 Density
• CPC Class Codes: B32B 2307/724 Permeability to gases, adsorption
• CPC Class Codes: B32B 2307/726 Permeability to liquids, absorption
• CPC Class Codes: B32B 2603/00 Vanes, blades, propellers, rotors with blades
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/30 comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/304 comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/322 comprising halogenated polyolefins, e.g. PTFE
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: F03D 1/065 : characterised by their construction elements F03D13/10 takes precedence
• CPC Class Codes: Y02E 10/72 : Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49336 : Blade making
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree

Abstract

A wind turbine blade is disclosed, at least 50% of the surface of which is covered with a self-adhesive, thermoplastic film. A method of manufacturing and repairing such a wind turbine blade is also disclosed. A two layer thermoplastic film suitable for covering the surface of a wind turbine blade is also disclosed. The film comprises a surface layer and a lower layer. The surface layer comprises 50% to 85% of polyvinylidene fluoride (PVDF), wherein up to 30% of the polyvinylidene fluoride may be replaced by hexafluoropropylene (HFP); and 10% to 45% polymethyl methacrylate (PMMA). The lower layer comprises 10% to 45% of a polyvinylidene fluoride (PVDF) polymer, wherein up to 30% of the polyvinylidene fluoride may be replaced by hexafluoropropylene (HFP); and 50% to 85% PMMA. Optionally the surface and/or lower layer comprises up to 8% UV stabilisers/absorbers; up to 10% matting agent; and up to 40% of an inorganic pigment. The film has an initial gloss of less than 30% when measured with a reflectometer at a angle of 60 degrees.

Claims

1-38. -38. (canceled)

39. A wind turbine blade at least 50% of the surface of which is covered with a self-adhesive, thermoplastic film, wherein the film is applied in a number of strips.

40. The wind turbine blade according to claim 39, wherein the film is applied in a number of strips arranged to reduce the complexity of curvature of each strip.

41. The wind turbine blade according to claim 39, wherein the edge of one strip overlaps with the edge of an adjacent strip.

42. The wind turbine blade according to claim 39, wherein edges of adjacent strip do not overlap and the join is covered with a further strip of thermoplastic film.

43. The wind turbine blade according to claim 39, wherein edges of adjacent strips do not overlap and the join is painted with a PVDF paint.

44. The wind turbine blade according to claim 39, wherein the thermoplastic film comprises at least one of an aliphatic polyurethane, a vinyl, an acrylic or a fluorinated thermoplastic.

45. The wind turbine blade according to claim 39, wherein substantially all of the blade is covered with the film covering.

46. The wind turbine blade according to claim 39, wherein the thermoplastic film comprises a two layer structure having an outer layer with enhanced weather resistant properties compared to the inner layer.

47. The wind turbine blade according to claim 46, wherein the inner layer has enhanced adhesion properties compared to the outer layer.

48. The wind turbine blade according to claim 46, wherein the inner and outer layers include polyvinylidene fluoride (PVDF) and polymethyl methacrylate (PMMA) with the outer layer having more PVDF than PMMA and the inner layer having more PMMA than PVDF.

49. The wind turbine blade according to claims 46, wherein the layers are co-extruded.

50. The wind turbine blade according to claim 39, wherein the thermoplastic film has an initial gloss of less than 30% when measured with a reflectometer at an angle of 60°

with respect to the film surface.

51. The wind turbine blade according to claim 39, wherein the thermoplastic film is less than 300˜

m thick, and preferably from 50 to 150˜

m thick.

52. The wind turbine blade according to claim 39, wherein the thermoplastic film is porous such that it is air permeable and water impermeable.

53. The wind turbine blade according to claim 39, wherein the adhesive is an acrylic or silicon based adhesive.

54. A method of manufacturing a wind turbine blade comprising moulding the blade body and adhering a thermoplastic film to at least 50% of the surface of the body, wherein the film is applied in a number of strips.

56. The method of manufacturing or repair according to claim 54, wherein the film is applied in a number of strips arranged to reduce the complexity of curvature of each strip.

57. The method of manufacturing or repair according to claim 54, wherein the edge of one strip overlaps with the edge of an adjacent strip.

58. The method of manufacturing or repair according to claim 54, wherein edges of adjacent strip do not overlap and the join is covered with a further strip of thermoplastic film.

59. The method of manufacturing or repair according to claim 54, wherein edges of adjacent strips do not overlap and the join is painted with a PVDF paint.

60. The method of manufacturing or repair according to claim 54, wherein the thermoplastic film is heated shortly before and/or during its application to the blade body.

61. A wind turbine blade manufactured according to the method of claim 54.

55. A method of repairing a wind turbine blade comprising adhering a thermoplastic film to at least 50% of the surface of a worn blade body, wherein the film is applied in a number of strips running between the leading and trailing edges of the blade.