PART ELEMENT FOR A WIND TURBINE BLADE AND METHOD FOR MANUFACTURING A PART ELEMENT FOR A WIND TURBINE BLADE

Abstract

Disclosed is a part element for a wind turbine blade and a method for manufacturing a part element. The part element comprises a primary sheet having a primary first side and a primary second side. The part element comprises a first fibre thread extending in a primary first direction and forming a first primary loop on the primary first side of the primary sheet from a primary first L1 point to a primary first L2 point. The part element comprises a second fibre thread extending in a primary second direction and forming a second primary loop extending from a primary second L1 point at the primary first side of the primary sheet to a primary second L2 point at the primary first side. A first pre-shaped element is positioned between the first fibre thread and the second fibre thread.

Claims

1. A method for manufacturing a part element for a wind turbine blade, the method comprising: providing a primary sheet having a primary first side and a primary second side, providing a first fibre thread extending in a primary first direction and forming a first primary loop on the primary first side of the primary sheet extending from a primary first L1 point at the primary first side of the primary sheet to a primary first L2 point at the primary first side, including anchoring the first fibre thread to the primary sheet, providing a second fibre thread extending in a primary second direction and forming a second primary loop on the primary first side of the primary sheet extending from a primary second L1 point at the primary first side of the primary sheet to a primary second L2 point at the primary first side, including anchoring the second fibre thread to the primary sheet, and providing a first pre-shaped element, and positioning the first pre-shaped element between the first fibre thread and the second fibre thread.

2. Method according to claim 1, wherein the first pre-shaped element is positioned after providing the first fibre thread and/or the second fibre thread.

3. Method according to claim 1 wherein the first fibre thread and the second fibre thread is provided such that the primary first direction and the primary second direction are parallel.

4. Method according to claim 1 comprising: providing a secondary sheet having a secondary first side and a secondary second side, and arranging the secondary sheet and the primary sheet such that the primary first side is facing the secondary second side, wherein the first primary loop is provided to extend to the secondary first side of the secondary sheet, and the second primary loop is provided to extend to the secondary first side of the secondary sheet, and wherein positioning the first pre-shaped element comprises positioning the first pre-shaped element between the primary sheet and the secondary sheet.

5. Method according to claim 4 wherein the secondary sheet comprises a first primary slit extending in a secondary first direction from a secondary first L1 point to a secondary first L2 point, and wherein arranging the primary sheet and the secondary sheet includes arranging the primary sheet and the secondary sheet such that the first primary slit is aligned with the first primary loop, and wherein the first primary loop is provided to extend to the secondary first side of the secondary sheet by pulling the first primary loop through the first primary slit in the secondary sheet.

6. Method according to claim 4 wherein the secondary sheet comprises a second primary slit extending in a secondary second direction from a secondary second L1 point to a secondary second L2 point, and wherein arranging the primary sheet and the secondary sheet includes arranging the primary sheet and the secondary sheet such that the second primary slit is aligned with the second primary loop, and wherein the second primary loop is provided to extend to the secondary first side of the secondary sheet by pulling the second primary loop through the second primary slit in the secondary sheet.

7. Method according to claim 1 comprising providing a first fibre strip, and pulling the first fibre strip through the first primary loop of the first fibre thread and the second primary loop of the second fibre thread.

8. Method according to claim 1 comprising transferring the primary sheet, the first pre-shaped element, and optionally the secondary sheet, from a first position to a second position, wherein transferring the primary sheet, the first pre-shaped element, and optionally the secondary sheet, comprises attaching a transportation structure to the first fibre thread and/or the second fibre thread.

9. Method according to claim 8 wherein transferring the primary sheet, the first pre-shaped element, and optionally the secondary sheet, comprises arranging the primary sheet, the first pre-shaped element, and optionally the secondary sheet, in a mould comprising an inclined surface, and wherein arranging the primary sheet, the first pre-shaped element, and optionally the secondary sheet, comprises aligning the part element on the inclined surface of the mould.

10. Method according to claim 1 wherein the primary sheet, the first pre-shaped element, and optionally the secondary sheet, are impregnated or infused with a resin and the method comprising curing the resin.

11. A part element for a wind turbine blade, the part element comprising a primary sheet having a primary first side and a primary second side, the part element comprising a first fibre thread extending in a primary first direction and forming a first primary loop on the primary first side of the primary sheet extending from a primary first L1 point to a primary first L2 point at the primary first side, and wherein the first fibre thread is anchored to the primary sheet, the part element comprising a second fibre thread extending in a primary second direction and forming a second primary loop on the primary first side of the primary sheet extending from a primary second L1 point at the primary first side of the primary sheet to a primary second L2 point at the primary first side, and wherein the second fibre thread is anchored to the primary sheet, and wherein a first pre-shaped element is positioned between the first fibre thread and the second fibre thread.

12. Part element according to claim 11 wherein the first pre-shaped element is a first pultruded element, such as a first pultruded strip.

13. Part element according to claim 11 wherein the primary first direction and the primary second direction are substantially parallel.

14. Part element according to claim 11 comprising a secondary sheet having a secondary first side and a secondary second side, and wherein the secondary sheet and the primary sheet are arranged such that the primary first side is facing the secondary second side, and wherein the first primary loop extends on the secondary first side of the secondary sheet, and the second primary loop extends on the secondary first side of the secondary sheet, and wherein the first pre-shaped element is positioned between the primary sheet and the secondary sheet.

15. Part element according to claim 11 wherein the secondary sheet comprises a first primary slit extending in a secondary first direction from a secondary first L1 point to a secondary first L2 point, and wherein the primary sheet and the secondary sheet are arranged such that the first primary slit is aligned with the first primary loop, and wherein the first primary loop extends through the first primary slit.

16. Part element according to claim 11 wherein the secondary sheet comprises a second primary slit extending in a secondary second direction from a secondary second L1 point to a secondary second L2 point, and wherein the primary sheet and the secondary sheet are arranged such that the second primary slit is aligned with the second primary loop, and wherein the second primary loop extends through the second primary slit.

17. Part element according to claim 15 wherein the secondary first direction and the secondary second direction are substantially parallel.

18. Part element according to claim 11, wherein the first fibre thread extends on the primary second side of the primary sheet from the primary first L1 point to a primary first L0 point, and extends on the primary second side of the primary sheet from the primary first L2 point to a primary first L3 point.

19. Part element according to claim 11, wherein the second fibre thread extends on the primary second side of the primary sheet from the primary second L1 point to a primary second L0 point, and extends on the primary second side of the primary sheet from the primary second L2 point to a primary second L3 point.

20. Part element according to claim 11 comprising a second pre-shaped element, such as a second pultruded element, arranged between the first fibre thread and the second fibre thread and aligned with the first pre-shaped element.

21. Part element according to claim 11 comprising a third fibre thread extending in a primary third direction and forming a third primary loop on the primary first side of the primary sheet from a primary third T1 point to a primary third T2 point, and wherein the primary third direction is different than the primary first direction and/or the primary second direction.

22. Part element according to claim 21, wherein the secondary sheet comprises a third primary slit extending from a secondary third T1 point to a secondary third T2 point, and wherein the third primary loop extends through the third primary slit.

23. A wind turbine blade comprising a part element according to claim 11, wherein the part element is connecting a first blade section and a second blade section of the wind turbine blade.

24. Wind turbine blade according to claim 23 wherein the first blade section extends along a longitudinal axis from a root to a first end and the second blade section extends along the longitudinal axis from a second end to a tip, the first blade section comprising a root region, and a first airfoil region, the second blade section comprising a second airfoil region with the tip, the part element forming a spar beam connecting the first blade section and the second blade section, the spar beam longitudinally extending along a spar beam axis from a first beam position to a second beam position and being positioned such that the first beam position is located in the first airfoil region and the second beam position is located in the second airfoil region and a third beam position, between the first beam position and the second beam position, is aligned with the second end of the second blade section.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0087] Embodiments of the invention will be described in more detail in the following with regard to the accompanying figures. Uke reference numerals refer to like elements throughout. Uke elements may, thus, not be described in detail with respect to the description of each figure. The figures show one way of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

[0088] FIG. 1 is a schematic diagram illustrating an exemplary wind turbine,

[0089] FIG. 2 is a schematic diagram illustrating an exemplary wind turbine blade,

[0090] FIG. 3 is a schematic diagram illustrating an exemplary wind turbine blade,

[0091] FIG. 4 is a schematic diagram illustrating an exemplary wind turbine blade,

[0092] FIG. 5a-5c are schematic diagrams illustrating an exemplary part of a wind turbine blade,

[0093] FIG. 6a-6c are schematic diagrams illustrating an exemplary part element,

[0094] FIG. 7 is schematic diagram illustrating an exemplary part element,

[0095] FIG. 8 is schematic diagram illustrating an exemplary part element,

[0096] FIG. 9a-9c are schematic diagrams illustrating an exemplary part element,

[0097] FIG. 10 is schematic diagram illustrating an exemplary part element,

[0098] FIG. 11 is schematic diagram illustrating an exemplary part element,

[0099] FIG. 12 is schematic diagram illustrating an exemplary part element,

[0100] FIG. 13 is schematic diagram illustrating an exemplary part element,

[0101] FIG. 14a-14d are schematic diagrams illustrating an exemplary part element, and

[0102] FIG. 15 is a block diagram of an exemplary method.

DETAILED DESCRIPTION

[0103] In the following figure description, the same reference numbers refer to the same elements and may thus not be described in relation to all figures.

[0104] FIG. 1 illustrates a conventional modern upwind wind turbine 2 according to the so-called “Danish concept” with a tower 4, a nacelle 6 and a rotor with a substantially horizontal rotor shaft. The rotor includes a hub 8 and three blades 10 extending radially from the hub 8, each having a blade root 16 nearest the hub and a blade tip 14 furthest from the hub 8.

[0105] FIG. 2 shows a schematic view of an exemplary wind turbine blade 10. The wind turbine blade 10 has the shape of a conventional wind turbine blade with a root end 17 and a tip end 15 and comprises a root region 30 closest to the hub, a profiled or an airfoil region 34 furthest away from the hub and a transition region 32 between the root region 30 and the airfoil region 34. The blade 10 comprises a leading edge 18 facing the direction of rotation of the blade 10, when the blade is mounted on the hub, and a trailing edge 20 facing the opposite direction of the leading edge 18.

[0106] The airfoil region 34 (also called the profiled region) has an ideal or almost ideal blade shape with respect to generating lift, whereas the root region 30 due to structural considerations has a substantially circular or elliptical cross-section, which for instance makes it easier and safer to mount the blade 10 to the hub. The diameter (or the chord) of the root region 30 may be constant along the entire root area 30. The transition region 32 has a transitional profile gradually changing from the circular or elliptical shape of the root region 30 to the airfoil profile of the airfoil region 34. The chord length of the transition region 32 typically increases with increasing distance r from the hub. The airfoil region 34 has an airfoil profile with a chord extending between the leading edge 18 and the trailing edge 20 of the blade 10. The width of the chord decreases with increasing distance r from the hub.

[0107] A shoulder 40 of the blade 10 is defined as the position, where the blade 10 has its largest chord length. The shoulder 40 is typically provided at the boundary between the transition region 32 and the airfoil region 34.

[0108] 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.

[0109] The wind turbine blade 10 comprises a blade shell comprising two blade shell parts or half shells, a first blade shell part 24 and a second blade shell part 26, typically made of fibre-reinforced polymer. The wind turbine blade 10 may comprise additional shell parts, such as a third shell part and/or a fourth shell part. The first blade shell part 24 is typically a pressure side or upwind blade shell part. The second blade shell part 26 is typically a suction side or downwind blade shell part. The first blade shell part 24 and the second blade shell part 26 are fastened together with adhesive, such as glue, along bond lines or glue joints 28 extending along the trailing edge 20 and the leading edge 18 of the blade 10. Typically, the root ends of the blade shell parts 24, 26 has a semi-circular or semi-oval outer cross-sectional shape.

[0110] FIG. 3 is a schematic diagram illustrating a cross sectional view of an exemplary wind turbine blade 10, e.g. a cross sectional view of the airfoil region of the wind turbine blade 10. The wind turbine blade 10 comprises a leading edge 18, a trailing edge 20, a pressure side 24, a suction side 26 a first spar cap 74, and a second spar cap 76. The wind turbine blade 10 comprises a chord line 38 between the leading edge 18 and the trailing edge 20. The wind turbine blade 10 comprises shear webs 42, such as a leading edge shear web and a trailing edge shear web. The shear webs 42 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 74, 76 may comprise carbon fibres while the rest of the shell parts 24, 26 may comprise glass fibres.

[0111] FIG. 4 is a schematic diagram illustrating an exemplary wind turbine blade 10, such as the wind turbine blade 10 of the previous figures. The wind turbine blade 10 comprises a leading edge 18, a trailing edge 20, a tip end 15 and a root end 17. The wind turbine blade 10 comprises shear webs 42, such as a leading edge shear web and a trailing edge shear web.

[0112] The wind turbine blade 10 is a so-called split blade, or two-part blade, or segmented blade. The wind turbine blade 10 comprises a first blade section 44 and a second blade section 46. The first blade section 44 extends along the longitudinal axis L from a root, such as the root end 17, to a first end 50. The second blade section 46 extends along the longitudinal axis L from a second end 52 to a tip, such as the tip end 15. The first blade section 44 comprises a root region 30, a first airfoil region 34a and a transition region 32 between the root region 30 and the first airfoil region 34a. The second blade section 46 comprises a second airfoil region 34b with the tip, such as the tip end 15. The first blade section 44 and the second blade section 46 may be connected with a spar beam 48.

[0113] FIG. 5a is a schematic diagram illustrating an exemplary part element 78′ of a wind turbine blade, such as a reinforced part of a blade shell part, such as the spar cap 74, 76 of FIG. 3. The part element 78′ may comprise a pultruded member 60, such pultruded strips such as pultrusion members of carbon, which is arranged on top of a biax element 62, such as glass fibres. During assembly, the pultruded member 60 may be transferred and laid upon the biax element 62 and the parts may be infused with resin. The pultruded member 60 may be 60 m long and transferring the pultruded member 60 may be challenging, as the long pultruded member 60 often bends, as illustrated in FIG. 5b, which is an enlarged view of FIG. 5a.

[0114] FIG. 5c is a schematic enlargement of the pultruded member 60 and the biax element 62, illustrating the potential situation when the pultruded member 60 is lowered and laid upon the biax element 62. Because the pultruded member 60 becomes slightly bent during transferal, the biax element 62 will compress underneath the parts of the pultruded member 60 corresponding to valleys. The compression of the biax element 62 may cause wrinkles and weaknesses in the biax element 62, which in turn may cause weaknesses in the part element 78 and/or a wind turbine blade comprising the part element 78′.

[0115] FIG. 6a-6c are schematic diagrams illustrating an exemplary part element 78. The part element 78 may mitigate some of the problems associated with the part element 78′ of FIG. 5a-c. The part element 78 comprises a primary sheet 80, such as a light fabric, such as glass fibre, and a fibre thread 86, such as a first fibre thread. The primary sheet 80 comprises fibres extending in the longitudinal L and the transverse T direction and has a primary first side 82 and a primary second side 84. The fibre thread 86 is sewn into the primary sheet 80 forming stitches 134 and loops 90, 130. When the fibre thread is sewn through the sheet and back out, a stitch is created.

[0116] The part element 78 in FIG. 6a is seen from the primary first side 82 of the primary sheet 80 and the part element 78 in FIG. 6b-6c is seen in a cross-sectional view. The fibre thread 86 extends in a first direction 88. The fibre thread 86 forms a primary loop 90 from a primary first L1 point PFL1 to a primary first L2 point PFL2 on the primary first side 82 of the primary sheet 80. The fibre thread 86 extends from a primary first L1 point PFL1 to a primary first L0 point PFL0 on the primary second side 84 of the primary sheet 80. The fibre thread 86 extends from a primary first L2 point PFL2 to a primary first L3 point PFL3 on the primary second side 84 of the primary sheet 80.

[0117] FIG. 6b Illustrates stitches 134 being backstitches, e.g. stitches where the fibre thread 86 crosses itself, thereby anchoring the fibre thread 86 at the backstitch 134 to the primary sheet 80. The fibre thread 86 may cross itself next to a loop or the fibre thread 86 may cross itself at a distance from the loop, e.g. extending on the primary second side 84 between the loop and the backstitch 134. FIG. 6c Illustrates stitches 134 being running stitches, e.g. stitches where the fibre thread 86 does not cross itself. With running stitches 134 the fibre thread 86 may be pulled at free ends, e.g. to tighten the fibre thread 86. The figures are examples of stitches, but any combination of the described stitches, or any other type of stitches, is possible. By placing backstitches after loops the size of the loop may be fixed.

[0118] FIG. 7 is a schematic diagram illustrating an exemplary part element 78, such as the part element of FIGS. 6a-c. The part element 78 comprises a primary sheet 80 and a first fibre thread 86′ extending in a primary first direction 88′. The first end 92′ of the first fibre thread 86′ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The first fibre thread 86′ forms stitches 134 and forms a first primary loop 90′ from a primary first L1 point PFL1 to a primary first L2 point PFL2. The part element 78 comprises a secondary sheet 100. The secondary sheet 100 comprises a first primary slit 102′ extending in a secondary first direction 108′ from a secondary first L1 point SFL1 to a secondary first L2 point SFL2. In FIG. 7 the first primary loop 90′ engages with the first primary slit 102′ by extending through the first primary slit 102′. The primary first L1 point PFL1 is aligned with the secondary first L1 point SFL1 and the primary first L2 point PFL2 is aligned with the secondary first L2 point SFL2.

[0119] FIG. 8 is a schematic diagram illustrating an exemplary part element 78, such as the part element of FIGS. 6-7. The part element 78 comprises a primary sheet 80 and a first fibre thread 86 extending in a primary first direction 88′. The first end 92′ of the first fibre thread 86′ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The first fibre thread 86′ forms stitches 134, a first primary loop 90′ and a first secondary loop 130′. The part element 78 comprises a secondary sheet 100. The secondary sheet 100 comprises a first primary slit 102′ and a first secondary slit 132′. In FIG. 8 the first primary loop 90′ engages with the first primary slit 102′ by extending through the first primary slit 102′ and the first secondary loop 90″ engages with the first secondary silt 102″ by extending through the slit 102″. A pre-shaped element 122 is arranged between the primary sheet 80 and the secondary sheet 100. The pre-shaped element 122 is aligned with the first primary loop 90′ and the first secondary loop 130′. The part element 78 illustrated in FIG. 8 may comprise more fibre threads, loops, stitches, slits and pre-shaped elements than illustrated in FIG. 8.

[0120] FIG. 9a-9c are schematic diagrams illustrating exemplary part elements 78, such as the part element of the previous FIGS. 6-8. FIG. 9a-9c Illustrates different solutions to retaining the pre-shaped elements. Two or more of the solutions may be combined or one of the solutions may be used.

[0121] FIG. 9a shows a part element 78 comprising a primary sheet 80 and loops 91. Pre-shaped elements 122 are arranged between the loops 91 and a fibre strip 120 extends in a direction perpendicular to the direction of the loops 91. The fibre strip 120 engages with the loops 91 to retain the pre-shaped elements 122. The fibre strip may be wide, such as in FIG. 9a, or the fibre strip may be narrow such as in FIG. 9b. The size of the loops 91 may be adjusted in accordance with the width of the fibre strip 120. The fibre strip 120 may engage with loops of a first column 124, as in FIG. 9a, and/or the fibre strip 120 may engage with loops of a plurality of columns, e.g. a first column 124 and a second column 126, such as illustrated in FIG. 9b.

[0122] FIG. 9c shows the part element 78 comprising a primary sheet 80 and a secondary sheet 100. The secondary sheet 100 comprises sifts 132 engaging with loops 91. Pre-shaped elements 122 are arranged between the primary sheet 80 and the secondary sheet 100 and aligned between the loops 91. A fibre strip 120 extends in a direction perpendicular to the direction of the loops 91. The fibre strip 120 is engaging with the loops 91.

[0123] For illustrative purposes, the part element 78 illustrated in the following figures are configured according to the solution in FIG. 9c, however any of the solutions illustrated in 9a-9c may be applied.

[0124] FIG. 10 is a schematic diagram illustrating an exemplary part element 78, such as the part element of FIGS. 6-9. The part element 78 comprises a primary sheet 80 and a first fibre thread 86′ extending in a primary first direction 88′. The first end 92′ of the first fibre thread 86′ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The first fibre thread 86′ forms a first primary loop 90′, between the primary first L1 point PFL1 and the primary first L2 point PFL2, and a first secondary loop 130′ between the primary first L3 point PFL3 and the primary first L4 point PFL4. A second fibre thread 86″ extends in a primary second direction 88″ and the first end 92″ of the second fibre thread 86″ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The second fibre thread 86″ forms a second primary loop 90″ between the primary second L1 point PSL1 and the primary second L2 point PSL2. The primary first direction 88′ and the primary second direction 88″ are substantially parallel. The primary first direction 88′ and/or the primary second direction 88″ and the longitudinal direction of the primary sheet L may be parallel. Alternatively, the primary first direction 88′ and/or the primary second direction 88″ and the transverse direction T of the primary sheet may be parallel, or the primary first direction 88′ and/or the primary second direction 88″ may be angled between the longitudinal direction L or the transverse direction T.

[0125] A third fibre thread 86′″ extends in a primary third direction 88′″ and the first end 92′″ of the third fibre thread 86′″ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The third fibre thread 86′″ forms a third primary loop 90′″ between the primary third T1 point PTT1 and the primary third T2 point PTT2. A fourth fibre thread 86″″ extends in a primary fourth direction 88″″ and the first end 92″″ of the fourth fibre thread 86″″ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The fourth fibre thread 86″″ forms a fourth primary loop 90″″ between the primary fourth T1 point PFT1 and the primary fourth T2 point PFT2. The primary third direction 88′″ and/or the primary fourth direction 88′″ and the transverse direction of the primary sheet T may be parallel. Alternatively, the primary third direction 88′″ and/or the primary fourth direction 88″″ and the longitudinal direction L of the primary sheet may be parallel, or the primary third direction 88′″ and/or the primary fourth direction 88″″ may be angled between the longitudinal direction L or the transverse direction T.

[0126] The part element 78 comprises a secondary sheet 100. The secondary sheet 100 comprises a first primary slit 102′ extending between a secondary first L1 point SFL1 and a secondary first L2 point SFL2, a first secondary slit 132′ between a secondary first L3 point SFL3 and a secondary first L4 point SFL4, a second primary slit 102″ between a secondary second L1 point SSL1 and a secondary second L2 point SSL2, a third primary slit 102′″ between a secondary third T1 point STT1 and a secondary third T2 point STT2, and a fourth primary slit 102″″ between a secondary fourth T1 point SFT1 and a secondary fourth T2 point SFT2. The first primary loop 90′ engages with the first primary slit 102′ by extending through the first primary slit 102′, the first secondary loop 130′ engages with the first secondary slit 132′ by extending through the first secondary slit 132′, the second primary loop 90″ engages with the second primary slit 102″ by extending through the second primary slit 102″, the third primary loop 90′″ engages with the third primary slit 102′″ by extending through the third primary slit 102′″, the fourth primary loop 90″″ engages with the fourth primary slit 102″″ by extending through the fourth primary slit 102″″.

[0127] A first pre-shaped element 122′ is arranged between the primary sheet 80 and the secondary sheet 100. The first pre-shaped element 122′ is arranged between the first primary loop 90′, the first secondary loop 130′, the second primary loop 90″, the third primary loop 90′″ and the fourth primary loop 90″″. The first pre-shaped element 122′ extends in a direction substantially parallel to the primary first direction 88′ and/or the primary second direction 88″. The first pre-shaped element 122′ extends in a transverse direction between the first fibre thread 86′ and the second fibre thread 86″. The first pre-shaped element 122′ extends in a longitudinal direction between the third fibre thread 86′″ and the fourth fibre thread 86″″.

[0128] A second pre-shaped element 122″ is aligned with the first pre-shaped element 122′. The second pre-shaped element 122″ is arranged between the primary sheet 80 and the secondary sheet 100. The second pre-shaped element 122″ is arranged between the first primary loop 90′, the first secondary loop 130′, the second primary loop 90″, the third primary loop 90′″ and the fourth primary loop 90″″. The second pre-shaped element 122″ extends in a direction substantially parallel to the primary first direction 88′ and/or the primary second direction 88″. The second pre-shaped element 122″ extends in a transverse direction between the first fibre thread 86′ and the second fibre thread 86″. The second pre-shaped element 122″ extends in a longitudinal direction between the third fibre thread 86′″ and the fourth fibre thread 86″″.

[0129] The part element 78 illustrated in FIG. 10 may comprise more fibre threads, loops, stitches, slits and/or pre-shaped elements than illustrated in FIG. 10.

[0130] FIG. 11 is a schematic diagram illustrating an exemplary part element 78, such as the part element of FIGS. 6-10. The part element 78 comprises a primary sheet 80 and a first fibre thread 86′ extending in a primary first direction 88′. The first end 92′ of the first fibre thread 86′ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The first fibre thread 86′ forms a first primary loop 90′ and a first secondary loop 130′. A second fibre thread 86″ extends in a primary second direction 88″ and the first end 92″ of the second fibre thread 86″ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The second fibre thread 86″ forms a second primary loop 90″ and a second secondary loop 130″. The primary first direction 88′ and the primary second direction 88″ are substantially parallel. A fifth fibre thread 86′″″ extends in a primary fifth direction 88′″″ and the first end 92′″″ of the fifth fibre thread 86′″″ is anchored to the primary sheet 80, e.g. with a backstitch (see FIG. 6b). The fifth fibre thread 86′″″ forms a fifth primary loop 90′″″ and a fifth secondary loop 130′″″. The primary first direction 88′ and the primary fifth direction 88′″″ are substantially parallel.

[0131] The part element 78 comprises a secondary sheet 100. The secondary sheet 100 comprises a first primary slit 102′, a first secondary slit 132′, a second primary slit 102″, a second secondary slit 132″, a fifth primary slit 102′″″ and a fifth secondary slit 132′″″. The loops engage with the corresponding slits by extending through the slits.

[0132] A first pre-shaped element 122′ is arranged between the primary sheet 80 and the secondary sheet 100. The first pre-shaped element 122′ is arranged between the first fibre thread 86′ and the second fibre thread 86″. The first pre-shaped element 122′ extends in a direction substantially parallel to the primary first direction 88′ and/or the primary second direction 88″. The first pre-shaped element 122′ extends in a transverse direction between the first fibre thread 86′ and the second fibre thread 86″.

[0133] A third pre-shaped element 122′″ is aligned with the first pre-shaped element 122′. The third pre-shaped element 122′″ is arranged between the primary sheet 80 and the secondary sheet 100. The third pre-shaped element 122′″ is arranged between the second fibre thread 86″ and the fifth fibre thread 86′″″. The third pre-shaped element 122′″ extends in a direction substantially parallel to the primary first direction 88′ and/or the primary second direction 88″ and/or the primary fifth direction 88′″″. The third pre-shaped element 122′″ extends in a transverse direction between the second fibre thread 86″ and the fifth fibre thread 86′″″.

[0134] The part element 78 illustrated in FIG. 11 may comprise more fibre threads, loops, stitches, slits and/or pre-shaped elements than illustrated in FIG. 11.

[0135] FIG. 12 is a schematic diagram illustrating an exemplary part element 78, such as the part element of FIGS. 6-11. The part element 78 comprises a plurality of pre-shaped elements arranged on a primary sheet 80. The part element 78 has an increased flexibility, because the pre-shaped elements 122 may be arranged differently for different areas of the part element 78, e.g. depending on the purpose of specific areas. The part elements 78 may have different lengths and/or widths. For illustrative purposes loops are not illustrated, but loops, as described with respect to previous figures, may be present between the pre-shaped elements 122. The pattern of the pre-shaped elements 78 may also improve the drapability of the part element 78.

[0136] FIG. 13 is a schematic diagram illustrating an exemplary part element 78, such as the part element of FIGS. 6-12. The part element 78 comprises a primary sheet 80 and a secondary sheet 100.

[0137] The primary sheet 80 comprises a fibre thread 86 forming loops 91. The secondary sheet 100 comprises slits 103. The loops 91 are engaging with the slits 103. Pre-shaped elements 122 are arranged between the primary sheet 80 and the secondary sheet 100. The part element 78 may be transferred, e.g. after assembly of the part element 78, by connecting the loops 91 to a transportation structure. The loops 91, which may be evenly distributed along the longitudinal direction of the pre-shaped elements support the pre-shaped elements 122 so that bending of the pre-shaped element 122 (e.g. as explained with respect to FIG. 5) may be reduced. The transportation structure 140 may be a bar with hooks.

[0138] FIG. 14a-14d are schematic diagrams illustrating exemplary part elements 78, such as the part element FIGS. 6-13.

[0139] The part element 78 may be transferred from a first position, such as a pre-form mould 152, as illustrated in FIG. 14a, to a second position, such as on a shell part, such as the first blade shell part and/or the second blade shell part 24, 26 in a blade shell mould 154 as illustrated in FIG. 14b.

[0140] FIG. 14a schematically illustrates a pre-form mould 152 wherein the part element 78 may be manufactured. The part element 78 may be assembled by providing a primary sheet 80 and positioning the primary sheet 80 in the pre-form mould 152. Pre-shaped elements 122 may be provided and positioned on the primary sheet 80. A secondary sheet 100 and/or fibre strips 120 may be provided to retain the pre-shaped elements 122 by engaging with the loops 91 of the primary sheet 80. The part element 78 may be lifted from the pre-form mould 152 and transferred to a blade shell mould 154 with a transportation structure, such as the transportation structure 140 of FIG. 13.

[0141] FIG. 14b shows a blade shell mould 154 with a part element 78. The part element 78 is laid on top of a blade shell part, such as a first blade shell part 24 or a second blade shell part 26. The part element 78 may form a spar cap, such as the spar cap 74, 76 of FIG. 3. The part element 78 may have a high drapability and may be able to adapt to curved surfaces, such as an internal surface of a blade shell part 24, 26. The part element 78 may be cured hereafter, e.g. by vacuum assisted resin transfer moulding (VARTM).

[0142] Alternatively, as schematically illustrated in FIG. 14c, the second position may be a mould 150 for manufacturing a spar beam. The part element 78 may be transferred, e.g. as shown in FIG. 13, and placed into the mould 150. Retaining the pre-shaped elements 122 with the loops 91 allows the part element 78 to be tilted towards an upright position while the pre-shaped elements 122 is maintained in their intended positions before and while the part element is cured. Due to the high drapability of the part element 78 and the retained pre-shaped elements 122, the part element 78 may follow the contour of the mould 150 with an inclination. For example, the mould side may incline at an angle between 0-90°. The fibre strip 120 illustrated in FIGS. 14a-14d may be any of the strips 120 illustrated in the previous figures. Alternatively, the fibre strip 120 may represent a sheet, such as a secondary sheet. When the part element 78 has been transferred to the mould 150 the part element 78 may be cured, e.g. by vacuum assisted resin transfer moulding (VARTM).

[0143] FIG. 14d shows a perspective view of the mould 150, as also illustrated in FIG. 14c, with a part element 78. The mould 150 in FIG. 14c-14d may be a mould for manufacturing a spar beam, such as the spar beam 48 in FIG. 4. However, moulds for manufacturing other parts of a wind turbine blade may also be used.

[0144] FIG. 15 is a block diagram of an exemplary method 200 for manufacturing a part element for a wind turbine blade, such as the part element 78 of previous figures.

[0145] The method 200 comprises providing 202 a primary sheet, such as the primary sheet 80 of previous figures, having a primary first side and a primary second side. The primary sheet comprising fibres, e.g. the primary sheet may comprise fibres extending in a longitudinal direction and in a transverse direction. The primary sheet comprising a first fibre thread extending in a primary first direction and forming a first primary loop on the primary first side of the primary sheet from a primary first L1 point to a primary first L2 point, and wherein a first end of the first fibre thread is anchored to the primary sheet.

[0146] The primary sheet may comprise a second fibre thread extending in a primary second direction and forming a second primary loop on the primary first side of the primary sheet from a primary second L1 point to a primary second L2 point. The first fibre thread and the second fibre thread may extend substantially parallel, and wherein the second fibre thread is anchored to the primary sheet.

[0147] The method 200 optionally comprises providing 204 a pre-shaped element. The method optionally comprises positioning 206 the pre-shaped element on the primary sheet, e.g. between the first fibre thread and the second fibre thread, e.g. between the first primary loop and the second primary loop. A second pre-shaped element may be provided and arranged on top of the first pre-shaped element, alongside the first pre-shaped element in the longitudinal direction, or alongside the first pre-shaped element in the transverse direction. The pre-shaped elements may have different lengths, widths and thicknesses.

[0148] The method 200 comprises providing 208 a secondary sheet, such as the secondary sheet 100 as described with respect to previous figures. The secondary sheet comprises a first primary slit and optionally a second primary slit. The method 200 comprises arranging 210 the secondary sheet such that the first primary slit is aligned with the first primary loop and optionally such that the second primary slit is aligned with the second primary loop, and optionally such that the pre-shaped element is arranged between the primary sheet and the secondary sheet. The method 200 optionally comprises pulling 212 the first primary loop through the first primary slit in the secondary sheet and optionally pulling 214 the second primary loop through the second primary sit in the secondary sheet.

[0149] The method 200 optionally comprises providing 216 a first fibre strip and pulling 218 the first fibre strip through the first primary loop of the first fibre thread and/or the second primary loop of the second fibre thread. The strip may be fastened or tightened to retain the pre-shaped elements.

[0150] The part element may comprise the secondary sheet without the fibre strip for retaining the pre-shaped elements. The part element may comprise the fibre strip without the secondary sheet for retaining the pre-shaped elements. The part element may comprise both the secondary sheet and the fibre strip for retaining the pre-shaped elements.

[0151] The method 200 comprises transferring 220 the part element from a first position to a second position. The first position may be a pre-form mould. The second position may be a mould for manufacturing for example a spar beam or a mould for manufacturing a blade shell part.

[0152] Transferring 220 the part element may comprise attaching 222 a transportation structure to the first fibre thread and/or the second fibre thread, e.g. attaching the first primary loop and/or the second primary loop to hooks in the transportation structure.

[0153] Transferring 220 the part element may comprise arranging 224 the part element in a mould comprising an inclined surface, and wherein arranging the part element comprises aligning the part element on the inclined surface of the mould. Alternatively, the part element may be arranged 224 on a blade shell part in a blade shell mould.

[0154] The method 200 optionally comprises curing 226 the part element and/or a wind turbine blade part comprising the part element. The part element may be cured in the first position, e.g. In the pre-form mould, or in the second position, e.g. In the mould or the blade shell mould. The part element may be cured by infusing the part element with a resin. Infusion may be provided by vacuum assisted resin transfer moulding (VARTM), e.g. with the part element in an inclined position or a substantially horizontal position.

[0155] FIG. 16 is a block diagram of an exemplary method 300 for manufacturing a part element for a wind turbine blade, such as the part element 78 of previous figures.

[0156] The method 300 comprises providing 302 a primary sheet, such as the primary sheet 80 of previous figures, having a primary first side and a primary second side.

[0157] The method 300 further comprises providing 304 a first fibre thread extending in a primary first direction and forming a first primary loop on the primary first side of the primary sheet. The loop is formed to extend from a primary first L1 point at the primary first side of the primary sheet to a primary first L2 point at the primary first side. Providing 304 the first fibre thread includes anchoring 306 the first fibre thread, such as a first end of the first fibre thread, to the primary sheet.

[0158] The method 300 comprises providing 308 a second fibre thread extending in a primary second direction and forming a second primary loop on the primary first side of the primary sheet. The loop is formed to extend from a primary second L1 point at the primary first side of the primary sheet to a primary second L2 point at the primary first side. Providing 308 the second fibre includes anchoring 310 the second fibre thread to the primary sheet.

[0159] The method 300 further comprises providing 312 a first pre-shaped element and positioning 314 the first pre-shaped element between the first fibre thread and the second fibre thread. Further pre-shaped elements may be provided and arranged on top of the first pre-shaped element, alongside the first pre-shaped element in the longitudinal direction, or alongside the first pre-shaped element in the transverse direction. The first pre-shaped element, and optionally any further pre-shaped elements, may be provided 312 after the first fibre thread and/or the second fibre thread has been provided 304, 308, as illustrated

[0160] The method 300 optionally comprises providing 316 a secondary sheet, such as the secondary sheet 100 as described with respect to previous figures. The method 300 may further comprise arranging 318 the secondary sheet and the primary sheet such that the primary first side of the primary sheet is facing the secondary second side of the secondary sheet.

[0161] Positioning 314 the first pre-shaped element may comprise positioning the first pre-shaped element between the primary sheet and the secondary sheet. The secondary sheet and the primary sheet may be arranged 318 prior to positioning 314 the first pre-shaped element, i.e. the first pre-shaped element may be positioned 314 after arranging 318 the secondary sheet and the primary sheet.

[0162] The secondary sheet may comprise a first primary sit and/or a second primary slit. The secondary sheet and the primary sheet may be arranged 318 such that the first primary slit is aligned with the first primary loop and/or such that the second primary slit is aligned with the second primary loop. The method 300 optionally comprises pulling 320 the first primary loop through the first primary slit and/or pulling 322 the second primary loop through the second primary slit.

[0163] The method 300 optionally comprises providing 324 a first fibre strip and pulling 326 the first fibre strip through the first primary loop of the first fibre thread and/or the second primary loop of the second fibre thread. The strip may be fastened or tightened to retain the pre-shaped elements.

[0164] The method 300 optionally comprises transferring 328 the part element, such as the primary sheet, the first pre-shaped element, and optionally the secondary sheet of the part element, from a first position to a second position. The first position may be a pre-form mould. The second position may be a mould for manufacturing for example a spar beam or a mould for manufacturing a blade shell part. Transferring 328 the part element may comprise attaching 330 a transportation structure to the first fibre thread and/or the second fibre thread, e.g. attaching the first primary loop and/or the second primary loop to hooks in the transportation structure.

[0165] Transferring 328 the part element may comprise arranging 332 the part element in a mould comprising an inclined surface, and wherein arranging the part element comprises aligning the part element on the inclined surface of the mould. Alternatively, the part element may be arranged 332 on a blade shell part in a blade shell mould.

[0166] The method 300 optionally comprises curing 334 the part element and/or a wind turbine blade part comprising the part element. For example, the part element may be impregnated and/or infused with resin and the resin may be cured. The part element may be cured in the first position, e.g. In the pre-form mould, or in the second position, e.g. In the mould or the blade shell mould.

[0167] The part element may be cured by infusing the part element with a resin. Infusion may be provided by vacuum assisted resin transfer moulding (VARTM), e.g. with the part element in an inclined position or a substantially horizontal position.

[0168] Exemplary embodiments are disclosed in the following items: [0169] 1. A part element for a wind turbine blade, the part element comprising a primary sheet having a primary first side and a primary second side, the primary sheet comprising a first fibre thread extending in a primary first direction and forming a first primary loop on the primary first side of the primary sheet from a primary first L1 point to a primary first L2 point, and wherein a first end of the first fibre thread is anchored to the primary sheet. [0170] 2. Part element according to item 1 comprising a secondary sheet, wherein the secondary sheet comprises a first primary slit extending in a secondary first direction from a secondary first L1 point to a secondary first L2 point. [0171] 3. Part element according to item 2, wherein the primary sheet and the secondary sheet is arranged such that the primary first L1 point of the primary sheet is aligned with the secondary first L1 point of the secondary sheet and the primary first L2 point of the primary sheet is aligned with the secondary first L2 point of the secondary sheet, and wherein the first primary slit is configured to receive part of the first fibre thread. [0172] 4. Part element according to any of the preceding items wherein the primary sheet comprises a second fibre thread extending in a primary second direction and forming a second primary loop on the primary first side of the primary sheet from a primary second L1 point to a primary second L2 point, the first fibre thread and the second fibre thread extending substantially parallel, and wherein a first end of the second fibre thread is anchored to the primary sheet. [0173] 5. Part element according to any of the preceding items, wherein the first fibre thread extends on the primary second side of the primary sheet from the primary first L1 point to a primary first L0 point, and extends on the primary second side of the primary sheet from the primary first L2 point to a primary first L3 point. [0174] 6. Part element according to any of the preceding items, wherein the second fibre thread extends on the primary second side of the primary sheet from the primary second L1 point to a primary second L0 point, and extends on the primary second side of the primary sheet from the primary second L2 point to a primary second L3 point. [0175] 7. Part element according to any of the preceding items, wherein the secondary sheet comprises a second primary slit, and wherein the second primary slit extends from a secondary second L1 point to a secondary second L2 point, and wherein the second primary slit is configured to receive part of the second fibre thread. [0176] 8. Part element according to any of the preceding items comprising a first pre-shaped element, such as a first pultruded strip, arranged between the first fibre thread and the second fibre thread. [0177] 9. Part element according to any of the preceding items comprising a second pre-shaped element, such as a second pultruded strip, arranged between the first fibre thread and the second fibre thread and aligned with the first pre-shaped element. [0178] 10. Part element according to any of the preceding items, wherein the primary sheet comprises a third fibre thread extending in a primary third direction and forming a third primary loop on the primary first side of the primary sheet from a primary third T1 point to a primary third T2 point, and wherein the primary third direction is different than the primary first direction and the primary second direction. [0179] 11. Part element according to any of the preceding items, wherein the secondary sheet comprises a third primary slit extending from a secondary third T1 point to a secondary third T2 point, wherein the third slit is configured to receive part of the third fibre thread. [0180] 12. A method for manufacturing a part element for a wind turbine blade, the method comprising providing a primary sheet having a primary first side and a primary second side, the primary sheet comprising a first fibre thread extending in a primary first direction and forming a first primary loop on the primary first side of the primary sheet from a primary first L1 point to a primary first L2 point, and wherein a first end of the first fibre thread is anchored to the primary sheet. [0181] 13. Method according to item 12 wherein the primary sheet comprises a second fibre thread extending in a primary second direction and forming a second primary loop on the primary first side of the primary sheet from a primary second L1 point to a primary second L2 point, the first fibre thread and the second fibre thread extending substantially parallel, and wherein the second fibre thread is anchored to the primary sheet. [0182] 14. Method according to item 13 comprising, e.g. after providing the primary sheet: [0183] providing a pre-shaped element, and [0184] positioning the pre-shaped element on the primary sheet between the first fibre thread and the second fibre thread. [0185] 15. Method according to item 14 comprising: [0186] providing a secondary sheet comprising a first primary slit and a second primary slit, [0187] arranging the secondary sheet such that the first primary slit is aligned with the first primary loop and the second primary slit is aligned with the second primary loop, and such that the pre-shaped element is arranged between the primary sheet and the secondary sheet, [0188] pulling the first primary loop through the first primary slit in the secondary sheet, and [0189] pulling the second primary loop through the second primary slit in the secondary sheet. [0190] 16. Method according to any of items 13-15 comprising [0191] providing a first fibre strip, and [0192] pulling the first fibre strip through the first primary loop of the first fibre thread and the second primary loop of the second fibre thread. [0193] 17. Method according to any of items 12-16 comprising transferring the part element from a first position to a second position, wherein transferring the part element comprises attaching a transportation structure to the first fibre thread and/or the second fibre thread. [0194] 18. Method according to item 17 wherein transferring the part element comprises arranging the part element in a mould comprising an inclined surface, and wherein arranging the part element comprises aligning the part element on the inclined surface of the mould. [0195] 19. Method according to any of items 12-18 comprising curing the part element. [0196] 20. A wind turbine blade comprising a part element according to any of items 1-11, wherein the part element is connecting a first blade section and a second blade section of the wind turbine blade. [0197] 21. Wind turbine blade according to Item 20 wherein the first blade section extends along a longitudinal axis from a root to a first end and the second blade section extends along the longitudinal axis from a second end to a tip, the first blade section comprising a root region, and a first airfoil region, the second blade section comprising a second airfoil region with the tip, [0198] the part element forming a spar beam connecting the first blade section and the second blade section, the spar beam longitudinally extending along a spar beam axis from a first beam position to a second beam position and being positioned such that the first beam position is located in the first airfoil region and the second beam position is located in the second airfoil region and a third beam position, between the first beam position and the second beam position, is aligned with the second end of the second blade section.

[0199] The invention has been described with reference to preferred embodiments. However, the scope of the invention is not limited to the illustrated embodiments, and alterations and modifications can be carried out without deviating from the scope of the invention.

LIST OF REFERENCES

[0200] 2 wind turbine [0201] 4 tower [0202] 6 nacelle [0203] 8 hub [0204] 10 blade [0205] 14 blade tip [0206] 15 tip end [0207] 16 blade root [0208] 17 root end [0209] 18 leading edge [0210] 20 trailing edge [0211] 24 first blade shell part (pressure side) [0212] 26 second blade shell part (suction side) [0213] 28 bond lines/glue joints [0214] 30 root region [0215] 32 transition region [0216] 34 airfoil region [0217] 34a first airfoil region [0218] 34b second airfoil region [0219] 40 shoulder [0220] 42 shear web or spar side [0221] 44 first blade section [0222] 46 second blade section [0223] 48 spar beam [0224] 50 first end [0225] 52 second end [0226] 60 pultruded member [0227] 62 biax element [0228] 74 first spar cap [0229] 76 second spar cap [0230] 78 part element [0231] 78′ part element [0232] 80 primary sheet [0233] 82 primary first side [0234] 84 primary second side [0235] 86 fibre thread [0236] 86′ first fibre thread [0237] 86″ second fibre thread [0238] 86′″ third fibre thread [0239] 86″″ fourth fibre thread [0240] 86′″″ fifth fibre thread [0241] 88′ primary first direction [0242] 88″ primary second direction [0243] 88″ primary third direction [0244] 90 primary loop [0245] 90′ first primary loop [0246] 90″ second primary loop [0247] 90′″ third primary loop [0248] 90″″ fourth primary loop [0249] 90′″″ fifth primary loop [0250] 91 loop [0251] 92′ first end of first fibre thread [0252] 92″ first end of second fibre thread [0253] 92′″″ first end of fifth fibre thread [0254] 100 secondary sheet [0255] 101A secondary first side [0256] 101B secondary second side [0257] 102 primary slit [0258] 102′ first primary slit [0259] 102″ second primary slit [0260] 102′″ third primary slit [0261] 102″″ fourth primary slit [0262] 102′″″ fifth primary slit [0263] 103 slit [0264] 108′ secondary first direction [0265] 120 fibre strip [0266] 122 pre-shaped element [0267] 122′ first pre-shaped element [0268] 122″ second pre-shaped element [0269] 122′″ third pre-shaped element [0270] 124 first column [0271] 126 second column [0272] 130 secondary loop [0273] 130′ first secondary loop [0274] 130″ second secondary loop [0275] 130″″ fifth secondary loop [0276] 132 first secondary slit [0277] 132′ second secondary slit [0278] 132″″ fifth secondary slit [0279] 134 stitch [0280] 136 spacing [0281] 140 transportation structure [0282] 150 mould [0283] 152 pre-form mould [0284] 154 blade shell mould [0285] PFL0 primary first L0 point [0286] PFL1 primary first L1 point [0287] PFL2 primary first L2 point [0288] PFL3 primary first L3 point [0289] SFL1 secondary first L1 point [0290] SFL2 secondary first L2 point [0291] PSL1 primary second L1 point [0292] PSL2 primary second L2 point [0293] SSL1 secondary second L1 point [0294] SSL2 secondary second L2 point [0295] PTT1 primary third T1 point [0296] PTT2 primary third T2 point [0297] STT1 secondary third T1 point [0298] STT2 secondary third T2 point [0299] PFT1 primary fourth T1 point [0300] PFT2 primary fourth T2 point [0301] 200 method [0302] 202 providing primary sheet [0303] 204 providing pre-shaped element [0304] 206 positioning pre-shaped element [0305] 208 providing secondary sheet [0306] 210 arranging secondary sheet [0307] 212 pulling first fibre thread through first primary slit [0308] 214 pulling second fibre thread through second primary silt [0309] 216 providing first fibre strip [0310] 218 pulling first fibre strip through first primary loop and second primary loop [0311] 220 transferring part element [0312] 222 attaching a transportation structure [0313] 224 arranging part element in mould [0314] 226 curing