Abstract
The present invention relates to a pre-impregnated fibre sheet extending in a longitudinal direction and in a transverse direction and comprising a first fibre layer forming part of an upper surface of the pre-impregnated fibre sheet and a second fibre layer forming part of a lower surface of the pre-impregnated fibre sheet, wherein the first fibre layer is pre-impregnated with an adhesion promotor. The present invention further relates to methods of manufacturing a blade shell member or wind turbine blade comprising a pre-manufactured spar cap and a number of pre-impregnated fibre sheets arranged to obtain an improved adherence between the blade shell and pre-manufactured spar cap, particularly when the pre-manufactured spar cap is resin infused with vinyl ester or epoxy resin and the blade mould is resin infused with polyester.
Claims
1. A pre-impregnated fibre sheet (20) extending in a longitudinal direction (25) and in a transverse direction (26) and comprising a first fibre layer (21) forming part of an upper surface of the pre-impregnated fibre sheet (20) and a second fibre layer (22) forming part of a lower surface of the pre-impregnated fibre sheet (20), wherein the first fibre layer (21) is pre-impregnated with an adhesion promotor.
2. The pre-impregnated fibre sheet (20) according to claim 1, wherein the second fibre layer (22) is not pre-impregnated with the adhesion promotor.
3. A pre-impregnated fibre sheet (20) according to claim 1, wherein the adhesion promotor is compatible with polyester resin and/or epoxy ester resin and/or vinyl ester resin and/or wherein the adhesion promotor is a primer and/or the adhesion promotor is isocyanate based and/or silane based and/or acrylate based and/or urethane based.
4. A pre-impregnated fibre sheet (20) according to claim 1, wherein the first fibre layer (21) comprises a first plurality of fibres (27) arranged along a first fibre direction (23) and the second fibre layer (22) comprises a second plurality of fibres (28) arranged along a second fibre direction (24).
5. A pre-impregnated fibre sheet (20) according to claim 1, wherein the first and second fibre directions (23, 24) are different and wherein a fibre angle between the first and second fibre directions (23, 24) is between 40 degrees and 150 degrees, preferably 90 degrees.
6. A pre-impregnated fibre sheet (20) according to claim 1, wherein the arrangement of the first plurality of fibres (27) and the arrangement of the second plurality of fibres (28) are maintained in the pre-impregnated fibre sheet (20) relative to each other by a plurality of stitching rows (29) and wherein the plurality of stitching rows (29) are parallel and arranged along a first stitch direction and wherein the first stitch direction is between the first and second fibre directions (23, 24), such as half the fibre angle from each of the first and second fibre directions (23, 24).
7. A pre-impregnated fibre sheet (20) according to claim 1, wherein the first and/or second plurality of fibres (27, 28) comprises or essentially consists of glass fibres.
8. A method of manufacturing a blade shell member for a wind turbine blade (1000) according to the first aspect of the present disclosure, comprising the steps of: a) providing a blade mould (70) for the blade shell member, the blade mould (70) comprising a moulding surface (71) and a moulding cavity (72); b) arranging a number of fibre-reinforced layers (80) on the blade moulding surface (71); c) providing a number of pre-impregnated fibre sheets (20) according to any of claims 1-7, including a first pre-impregnated fibre sheet (20a) and a second pre-impregnated fibre sheet (20b) each comprising a first fibre layer (21) forming part of an upper surface of the pre-impregnated fibre sheet and a second fibre layer (22) forming part of a lower surface of the pre-impregnated fibre sheet (20), wherein the first fibre layer (21) is pre-impregnated with an adhesion promotor; d) providing a pre-manufactured spar cap (100) having an upper surface (101), a lower surface (102) opposite the upper surface, a first side surface (103), a second side surface (104), a first end surface (105) and a second end surface (106); e) arranging the pre-manufactured spar cap (100) at a spar cap region (73) on top of the fibre-reinforced layers (80); f) infusing the blade moulding cavity (72) with resin; and g) curing the resin to form the blade shell member; wherein the method further comprises a step of arranging the first pre-impregnated fibre sheet (20a) on top of the number of fibre-reinforced layers (80) on at least part of the spar cap region (73) before step e), such that the second fibre layer (22) contacts the at least part of the spar cap region (73) and/or wherein the method further comprises the step of arranging the second pre-impregnated fibre sheet (20b) on at least part of the upper surface (101) of the pre-manufactured spar cap (100) before step f) and preferably after step e) and such that the upper surface (101) of the pre-manufactured spar cap (100) contacts the first fibre layer (21) of the second pre-impregnated fibre sheet (20b).
9. Method according to claim 8, wherein the method further comprises the step of applying a primer layer to at least part of the spar cap region (73) before step e) or applying a primer layer to at least part of the upper surface (101) of the pre-manufactured spar cap (100) before step f).
10. Method according to claim 8, wherein the method further comprises arranging further fibre-reinforced layers (83) in the blade mould (70), including arranging further fibre-reinforced layers (83) on top of the second pre-impregnated sheet (20b), before step f) and after step e), such that the further fibre-reinforced layers (83) are contacted with the second fibre layer (22) of the second pre-impregnated sheet (20b).
11. Method according to claim 8, wherein providing the pre-manufactured spar cap (100) comprises the steps of: c1) providing a plurality of pultruded carbon elements (110) and a number of interlayers (130) comprising fibre material for promoting resin flow between the pultruded carbon elements (110); c2) arranging the plurality of pultruded carbon elements (110) in a stacked array, wherein the plurality of pultruded carbon elements (110) is separated by the number of interlayers (130); and c5) infusing the plurality of pultruded carbon elements (110) with resin and curing to provide the pre-manufactured spar cap (100).
12. Method according to claim 8 wherein the pre-manufactured spar cap (100) is infused with vinyl ester or epoxy ester resin and wherein the blade mould cavity (73) is infused with polyester resin.
13. Method according to claim 8, wherein the number of fibre-reinforced layers (80) and/or further fibre-reinforced layers (83) comprises glass fibres and/or carbon fibres and/or wherein the number of fibre-reinforced layers (80) and/or further fibre-reinforced layers (83) comprises unidirectional layers and/or biaxial layers and/or triaxial layers.
14. Blade shell member for a wind turbine blade (1000) obtainable by the method of claim 8.
15. Wind turbine blade (1000) obtainable by manufacturing a pressure side shell half and a suction side shell half over substantially the entire length of the wind turbine blade in accordance with claim 8 and subsequently closing and joining the shell halves for obtaining a closed shell.
Description
DETAILED DESCRIPTION OF THE INVENTION
[0075] The invention is explained in detail below with reference to embodiments shown in the drawings, which shall not be construed as limitations.
[0076] FIG. 1 is a schematic diagram illustrating a wind turbine,
[0077] FIG. 2 is a schematic diagram illustrating a wind turbine blade and a spar cap structure arranged within the wind turbine blade,
[0078] FIG. 3 is a schematic diagram illustrating a pre-manufactured spar arranged on a preparation table and in a sling according to an embodiment of the present invention. Furthermore, part of a blade mould and a spar cap region are illustrated.
[0079] FIG. 4 is a schematic diagram illustrating different views of a pre-impregnated fibre sheet according to a preferred embodiment of the present invention,
[0080] FIG. 5 is a schematic diagram illustrating a cross-sectional view of the blade mould of FIG. 3 and method steps of providing a blade shell member according to embodiments of the present invention,
[0081] FIG. 6 is a schematic diagram illustrating a close-up view of a first and second pre-impregnated sheet arranged at the interface between a pre-manufactured spar cap and the remaining blade shell member parts,
and
[0082] FIG. 7 is a schematic diagram illustrating a pre-impregnated fibre sheet arranged in different rolled-up configurations.
DETAILED DESCRIPTION
[0083] FIG. 1 illustrates a conventional modern upwind wind turbine according to the so-called Danish concept with a tower 400, a nacelle 600 and a rotor with a substantially horizontal rotor shaft. The rotor includes a hub 800 and three blades 1000 extending radially from the hub 800, each having a blade root 1600 nearest the hub and a blade tip 1400 furthest from the hub 800.
[0084] FIG. 2A shows a schematic view of a first embodiment of a wind turbine blade 1000 according to the invention. The wind turbine blade 1000 has the shape of a conventional wind turbine blade and comprises a root region 3000 closest to the hub, a profiled or an airfoil region 3400 furthest away from the hub and a transition region 3200 between the root region 3000 and the airfoil region 3400. The blade 1000 comprises a leading edge 1800 facing the direction of rotation of the blade 1000, when the blade is mounted on the hub, and a trailing edge 2000 facing the opposite direction of the leading edge 1800.
[0085] The airfoil region 3400 (also called the profiled region) has an ideal or almost ideal blade shape with respect to generating lift, whereas the root region 3000 due to structural considerations has a substantially circular or elliptical cross-section, which for instance makes it easier and safer to mount the blade 1000 to the hub. The diameter (or the chord) of the root region 3000 may be constant along the entire root region 3000. The transition region 3200 has a transitional profile gradually changing from the circular or elliptical shape of the root region 3000 to the airfoil profile of the airfoil region 3400. The chord length of the transition region 3200 typically increases with increasing distance r from the hub. The airfoil region 3400 has an airfoil profile with a chord extending between the leading edge 1800 and the trailing edge 2000 of the blade 1000. The width of the chord decreases with increasing distance r from the hub.
[0086] A shoulder 4000 of the blade 1000 is defined as the position where the blade 100 has its largest chord length. The shoulder 4000 is typically provided at the boundary between the transition region 3200 and the airfoil region 3400.
[0087] It should be noted that the chords of different sections of the blade normally do not lie in a common plane since the blade may be twisted and/or curved (i.e. pre-bent), thus providing the chord plane with a correspondingly twisted and/or curved course, this being most often the case in order to compensate for the local velocity of the blade being dependent on the radius from the hub.
[0088] FIG. 2B is a schematic diagram illustrating a cross-sectional view of an exemplary wind turbine blade 1000, e.g. a cross-sectional view of the airfoil region of the wind turbine blade 1000. The wind turbine blade 1000 comprises a leading edge 1800, a trailing edge 2000, a pressure side 2400, a suction side 2600, a first spar cap 100 and a second spar cap 100. The wind turbine blade 1000 comprises a chord line 3800 between the leading edge 1800 and the trailing edge 2000. The wind turbine blade 1000 comprises shear webs 82, such as a leading edge shear web and a trailing edge shear web. The shear webs 82 could alternatively be a spar box with spar sides, such as a trailing edge spar side and a leading edge spar side. The spar caps 100 may comprise carbon fibres while the rest of the shell parts 2400, 2600 may comprise glass fibres.
[0089] FIG. 3A is a schematic diagram illustrating a cross-sectional view along the width of a pre-manufactured spar cap 100 according to an embodiment of the present invention. In FIG. 3A, a finished pre-manufactured spar cap 100 is arranged on a preparation table 90.
[0090] FIG. 3B is a schematic diagram illustrating a three-dimensional view of the pre-manufactured spar cap 100 arranged in a sling 91 which is further coupled to a beam 92. As can be seen in FIG. 3B, the pre-manufactured spar cap 100 is an elongated element having an upper surface 101, a lower surface 102 (not visible), a first side surface 103, a second side surface 104 (not visible), a first end surface 105 and a second end surface 106 (not visible). The upper surface 101 and lower surface 102 are preferably arranged opposite each other and may have substantially the same size. In the same way, the first and second side surfaces 103, 104 may be arranged opposite each other and have substantially the same sizes, and the first and second end surfaces 105, 106 are arranged opposite each other and preferably have substantially the same sizes. However, since the shape of the spar cap 100 is set according to strength requirements, the thickness may change along the longitudinal direction of the spar cap 100, resulting in tapering sections at the sides and/or the ends (not visible in drawing). The pre-manufactured spar cap 100 comprises a plurality of elongated pultruded carbon elements 110 arranged in a stacked array. The plurality of pultrusion carbon elements 110 is separated by a number of interlayers 130 arranged to promote resin-infusion between the pultruded carbon elements.
[0091] In FIG. 3A, the stacked array of pultruded carbon elements 110 comprises three rows arranged adjacently, and each row comprises six pultruded carbon elements 110 arranged on top of each other. Five interlayers 130 are arranged between the pultruded carbon elements 110 arranged on top of each other, extending from the first to the third row of pultruded carbon elements 110. In FIG. 3B, the stacked array of pultruded carbon elements 110 comprises three rows arranged adjacently, and each row comprises four pultruded carbon elements 110 arranged on top of each other. Three interlayers 130 are arranged between the pultruded carbon elements 110 arranged on top of each other, extending from the first to the third row of pultruded carbon elements 110.
[0092] The pre-manufactured spar cap 100 is preferably infused with vinyl ester resin or epoxy ester resin to maintain the pultruded carbon elements 110 in the stacked array. The pultruded carbon elements 110 are preferably elongated planks with a rectangular cross-section and made from carbon fibres in a cured resin. Alternatively, they may be hybrid pultrusion elements comprising a second type of reinforcement fibres, such as glass fibres. The interlayers 130 comprise fibre material, such as glass fibres, carbon fibres or polymeric fibres etc. for promoting resin flow between the pultruded carbon planks.
[0093] The sling 91 is an example of an element for lifting the spar cap 100 from the preparation table 90 to the blade mould 70. As can be seen, the sling 91 is arranged around the spar cap 100 and thus contacts the lower surface 102 of the spar cap 100, as well as the first and second side surfaces 103, 104 of the spar cap 100. This means that if a primer layer is applied to the lower surface 102 and/or side surfaces 103, 104 of the spar cap, the lifting of the spar cap from the preparation table 90 to the blade mould 70 may damage the applied primer layers. In reality, the pre-manufactured spar cap 100 is much longer than illustrated in FIG. 3B.
[0094] FIG. 3C is a schematic diagram illustrating a three-dimensional view of a part of a blade mould 70 for moulding a blade shell member, such as a suction side blade shell member or a pressure side blade shell member. Only a middle part of the blade mould 70 relative to a longitudinal direction 74 is illustrated, whereas the ends for moulding the tip and root of the blade shell member are not illustrated. The blade mould 70 comprises a spar cap region 73 extending along the longitudinal axis 74 of the blade mould. The spar cap region 73 is the region where the pre-manufactured spar cap 100 is to be arranged, i.e. the spar cap region 73 preferably has the same length and width as the lower surface 102 of the pre-manufactured spar cap 100.
[0095] The blade mould 70 comprises a moulding surface 71 whereon the different materials for the blade shell member can be arranged. Furthermore, the blade mould 70 comprises a moulding cavity 72. The moulding cavity 72 is the space between the moulding surface 71 and a plane between which the different materials for the blade shell member may be arranged. The cavity 72 is illustrated in FIG. 5A.
[0096] FIG. 4 is a schematic diagram illustrating different views of a pre-impregnated fibre sheet according to a preferred embodiment of the present invention.
[0097] FIG. 4A shows a pre-impregnated fibre sheet 20 extending in a longitudinal direction 25 and in a transverse direction 26 and comprising a first fibre layer 21 forming part of an upper surface of the pre-impregnated fibre sheet and a second fibre layer 22 forming part of a lower surface of the pre-impregnated fibre sheet 20. The first fibre layer 21 is pre-impregnated with an adhesion promotor (not visible), whereas the second fibre layer 22 is not.
[0098] FIG. 4B illustrates a top view of a first and second fibre layer 21, 22 arranged beside each other. The first fibre layer 21 comprises a first plurality of fibres 27 arranged along a first fibre direction 23, and the second fibre layer 22 comprises a second plurality of fibres 28 arranged along a second fibre direction 24.
[0099] FIG. 4C illustrates a top view of a pre-impregnated fibre sheet 20 made by arranging the first and second fibre sheets of FIG. 4B on top of each other. For illustrative purposes, the arrangement of the first plurality of fibres 27 and the second plurality of fibres 28 in the pre-impregnated fibre sheet 20 is shown. The plurality of first and second fibres 27, 28 are each arranged at a 45-degree angle relative to the longitudinal direction 25 of the pre-impregnated fibre sheet 20, and the fibre angle between the first and second fibre directions is 90 degrees.
[0100] The fibres 27, 28 are maintained relative to each other by a plurality of stitching rows 29 arranged along a first stitch direction between the first and second fibre directions. The stitching rows are illustrated by dotted lines extending along the longitudinal direction 25 of the pre-impregnated fibre sheet 20. In FIG. 4C, the first stitch direction is parallel with the longitudinal direction 25 of the pre-impregnated fibre sheet 20.
[0101] FIG. 4D is a cross-sectional view of the pre-impregnated fibre sheet through the line A-A in FIG. 4A.
[0102] FIG. 5A is a schematic diagram illustrating a cross-sectional view of the blade mould 70 of FIG. 3. The thick black lines illustrate substantially straight areas of the blade mould 70 between which a plane Y extends. The area between the plane Y and the moulding surface 71 is defined as the moulding cavity 72. FIG. 5A further illustrates the spar cap region 73, i.e. the region of the blade mould 70 where the spar cap 100 is to be arranged. The spar cap 100 is not to be arranged directly on the blade moulding surface 71 but in the area above the spar cap region 73 on fibre-reinforced layers 80.
[0103] FIG. 5B is a schematic diagram illustrating an arrangement of a number of fibre-reinforced layers 80 on the blade moulding surface 71 of the blade mould 70. In FIG. 5B, three fibre-reinforced layers 80 are arranged on top of each other, forming a thin outer shell 81 of the blade shell member, as illustrated in FIG. 5C. In reality, the outer shell 81 is much thinner than illustrated in FIG. 5C. However, for illustrative purposes, the outer shell 81 proportions are exaggerated. Furthermore, in reality, more than three fibre-reinforced layers 80 may be arranged on top of each other, but for an illustrative purpose, only three layers are shown.
[0104] FIG. 5C is a schematic diagram illustrating how a first pre-impregnated fibre sheet 20a may be arranged on top of the fibre-reinforced layers 80 in the blade mould 70. The first pre-impregnated fibre sheet 20 is shown as a thick black line for illustrative purposes. The first pre-impregnated fibre sheet 20 may be applied outside the spar cap region 73, i.e. covering an area larger than the spar cap region, or may only cover some parts of the spar cap region 73. However, preferably, the first pre-impregnated fibre sheet 20 or a plurality of first pre-impregnated sheets substantially covers the entire spar cap region. Alternatively, a primer layer could be applied instead of the first pre-impregnated fibre sheet 20.
[0105] FIGS. 5D-5F illustrate that in some embodiments, after the first pre-impregnated fibre sheet 20a has been arranged on the spar cap region 73 on top of the fibre-reinforced layers 80, the pre-manufactured spar cap may be arranged on the first pre-impregnated fibre sheet 20a before the second pre-impregnated fibre sheet 20b is arranged on the upper surface 101 of the pre-manufactured spar cap 100. Thus, the second pre-impregnated fibre sheet is arranged at the upper surface 101 of the pre-manufactured spar cap 100 after the pre-manufactured spar cap 100 has been arranged in the blade mould 70. A primer layer may be applied instead of the second pre-impregnated fibre sheet 20b.
[0106] FIGS. 5G-FI illustrate that in other embodiments, whereafter the first pre-impregnated fibre sheet 20a has been arranged on the spar cap region 73 on top of the fibre-reinforced layers 80, the second pre-impregnated fibre sheet 20b is arranged on the upper surface 101 of the pre-manufactured spar cap before it is arranged in the blade mould 70 and that only after arranging the second pre-impregnated fibre sheet 20b on the upper surface 101 of the pre-manufactured spar cap 100, the pre-manufactured spar cap 100 is lifted into the blade mould and arranged at the spar cap region 73. A primer layer may be applied instead of the second pre-impregnated fibre sheet 20b.
[0107] Furthermore, the side surfaces and/or end surfaces of the spar cap may also be covered by a pre-impregnated fibre sheet or a primer layer.
[0108] FIGS. 5J-5K illustrate that after the second pre-impregnated sheet 20b has been arranged on the upper surface 101 of the pre-manufactured spar cap 100, independently of whether this was done in accordance with the embodiment illustrated in FIGS. 5D-5F or 5G-FI, further elements 82, such as sandwich core layers, shear webs and further fibre-reinforced layers 83, may be arranged within the cavity of the blade mould 70. After arranging the desired elements within the cavity of the blade mould 70, the blade mould 70 can be infused with resin and cured to form a finished blade shell member. Infusion of the blade mould cavity with resin is preferably based on vacuum-assisted resin transfer moulding.
[0109] FIGS. 5A-5K illustrate the manufacture of a pressure side shell part. It is recognised that a suction side shell part may be manufactured in a similar way. The two shell parts can subsequently be assembled to form a closed aerodynamic shell, e.g. with shear webs between the spar caps as illustrated in FIG. 2B.
[0110] It should be emphasised that the figures. are schematic only and that in particular the thickness of the different elements in FIG. 5 is exaggerated. Normally, the blade shell and spar cap are much thinner, e.g. as shown in FIG. 2B.
[0111] FIG. 6 is a schematic illustration illustrating a close-up view of FIG. 5L. As can be seen in FIG. 6, the interface between the spar cap 100 and the blade shell member parts, i.e. the fibre reinforced layers 80 and the further fibre reinforced layers 83, is covered by a first and a second pre-impregnated fibre sheet 20a, 20b. Preferably, the first and second pre-impregnated fibre sheets should be similar to those illustrated in FIG. 4. It can be seen from FIG. 6 that the first pre-impregnated fibre sheet 20a is arranged on top of the number of fibre-reinforced layers 80 of the spar cap region 73, such that the second fibre layer 22 contacts the spar cap region 73 and such that the first fibre layer 21 contacts the lower surface 102 of the spar cap 100. It can further be seen that the second pre-impregnated fibre sheet 20b is arranged on the upper surface 101 of the pre-manufactured spar cap 100, such that the upper surface 101 of the pre-manufactured spar cap 100 contacts the first fibre layer 21 of the second pre-impregnated fibre sheet 20a and such that the second fibre layer 22 contacts the further fibre-reinforced layers 83. Again, it should be emphasised that the figures are schematic only and that in particular the thicknesses of the different elements in FIG. 6 are not necessarily in the correct dimensions relative to each other.
[0112] FIGS. 7A and 7B are schematic illustrations showing how a pre-impregnated fibre sheet 20 may be provided in a rolled-up configuration. As can be seen, the upper surface of the pre-impregnated fibre sheet 20, i.e. the first fibre layer 21, is covered by a removable film 30, which can be removed when desired, either while rolling out the pre-impregnated fibre sheet 20 or after it has been rolled out.
[0113] The pre-impregnated fibre sheet 20 may be rolled up as illustrated in FIG. 7A or as in FIG. 7B. Whether the pre-impregnated fibre sheet 20 should be rolled up as shown in FIG. 7A or 7B depends on whether the pre-impregnated fibre sheet 20 are to be rolled out on the spar cap region 73 in the blade mould 70 or on the upper surface 101 of the pre-manufactured spar cap 100.
[0114] For a first pre-impregnated fibre sheet 20a configured to be rolled out on a spar cap region 73 in the blade mould 70, the pre-impregnated fibre sheet 20a is preferably rolled up as shown in FIG. 7A, such that the first fibre layer 21 faces upwards relative to the blade mould and the second fibre layer 22 is contacted with the spar cap region 73 of the blade mould, i.e. the fibre-reinforced layers 80 arranged at the spar cap region 73. In this case, the film 30 may be removed simultaneously with or after rolling out the pre-impregnated fibre sheet 20a.
[0115] For a second pre-impregnated fibre sheet 20b configured to be rolled out on the upper surface 101 of a spar cap 100, the pre-impregnated fibre sheet 20b is preferably rolled up as shown in FIG. 7B, such that the second fibre layer 22 faces upwards relative to the pre-manufactured spar cap 100 and such that the first fibre layer 21 is contacted with the upper surface 101 of the pre-manufactured spar cap 100. In this case, it may be necessary to remove the film 30 substantially simultaneously with rolling out the pre-impregnated fibre sheet 20b.
[0116] FIG. 7C is a schematic illustration showing that a pre-impregnated fibre sheet 20 provided in a rolled-up configuration may be rolled out along a surface, e.g. along the spar cap region 73 in the blade mould 70 or the upper surface 101 of the pre-manufactured spar cap 100. In FIG. 7C, the pre-impregnated fibre sheet 20 is arranged on a wheel 93, connected to a device 94. The wheel 93 can be rotated relative to the device 94 to facilitate rollout of the pre-impregnated fibre sheet 20. Furthermore, the device 94 itself may have wheels to allow the device to be moved along the surface 95, i.e. along the spar cap region 73 in the blade mould 70 or on the upper surface 101 of the pre-manufactured spar cap 100.
LIST OF REFERENCE NUMERALS
[0117] 20 pre-impregnated fibre sheet [0118] 21 first fibre layer [0119] 22 second fibre layer [0120] 23 first fibre direction [0121] 24 second fibre direction [0122] 25 longitudinal direction of fibre sheet [0123] 26 transverse direction of fibre sheet [0124] 27 first plurality of fibres [0125] 28 second plurality of fibres [0126] 29 stitching rows [0127] 30 film [0128] 70 blade mould [0129] 71 moulding surface [0130] 72 moulding cavity [0131] 73 spar cap region [0132] 74 longitudinal direction [0133] 80 fibre-reinforced layer [0134] 81 outer shell of wind turbine shell member [0135] 82 further elements, such as core elements and/or shear webs [0136] 83 further fibre-reinforced layers [0137] 90 preparation table [0138] 91 sling [0139] 92 beam [0140] 93 wheel [0141] 94 device [0142] 95 surface [0143] 100 pre-manufactured spar cap [0144] 101 upper surface of spar cap [0145] 102 lower surface of spar cap [0146] 103 first side surface of spar cap [0147] 104 second side surface of spar cap [0148] 105 first end surface of spar cap [0149] 106 second end surface of spar cap [0150] 110 pultruded carbon element [0151] 130 interlayers [0152] 200 wind turbine [0153] 400 tower [0154] 600 nacelle [0155] 800 hub [0156] 1000 blade [0157] 1400 blade tip [0158] 1600 blade root [0159] 1800 leading edge [0160] 2000 trailing edge [0161] 2200 pitch axis [0162] 2400 pressure side [0163] 2600 suction side [0164] 3000 root region [0165] 3200 transition region [0166] 3400 airfoil region [0167] 3800 chord line [0168] 4000 shoulder/position of maximum chord
