A multi-sequence UD molding method for wind turbine blades

Abstract

The present invention provides a multi-sequence UD molding method for wind turbine blades, comprising the following steps: S1, UD mold preparation: cleaning the UD mold surface and applying a release agent to the inner surface of the UD mold; S2, sequentially laying a first continuous felt and a first release cloth on the UD mold; S3, laying a first sequence UD cloth layer; S4, preparing a silicone mold; S5, laying a second sequence UD cloth layer; S6, connecting the silicone mold to the first sequence UD cloth layer and the second sequence UD cloth layer; S7, establishing vacuum, maintaining pressure, and performing pouring and curing. The present invention, by using a silicone mold and positioning the silicone mold after laying a first sequence UD cloth layer, can achieve one-time pouring molding of multi-sequence UD, and the side edges between the first sequence UD and the second sequence UD are smoother, thereby improving the matching of the multi-sequence UD and the shell core material molding, and improving the shell molding efficiency and quality.

Description

Technical Field

[0001] The present invention relates to the technical field of non-metallic composite material processing and forming, and in particular to a multi-sequence UD forming method for a wind turbine blade. Background Art

[0002] As a key component of a wind turbine, the design and performance of wind turbine blades directly impact the turbine's wind capture capacity and power generation efficiency. Blades capture wind energy and convert it into mechanical energy, which in turn drives the generator to generate electricity. Trailing edge (UD) plays a crucial role in the blade's structure, primarily by enhancing its structural strength and rigidity. This, in turn, improves the stability and reliability of the entire turbine, ensuring safe operation in complex and changing environmental conditions.

[0003] Trailing edge UD positioning, specifically the placement and placement of UDs along the trailing edge of the blade, significantly impacts the flexural stability of wind turbine blades. Buckling stability is a key metric for evaluating a blade's ability to resist deformation, and is particularly crucial for wind turbine blades, which are subject to significant wind loads. As wind turbines become larger, an increasing number of ultra-large blades are adopting multi-sequence UD structures to meet the required trailing edge buckling strength requirements. Some UDs utilize staggered layers, while others utilize non-staggered block structures.

[0004] Currently, multi-sequence UD molding generally uses a phased infusion solution, which results in long molding cycles, waste of auxiliary consumables and resin, and no effective solution to ensure the flatness of the leading edge. After vacuum tightening, the leading edge of the UD will produce an arc shape. After demolding, this area cannot be well matched with the shell core material. Usually, the arc area needs to be filled with yarn, padding, and adding pads. On the one hand, this affects on-site work efficiency, and on the other hand, improper handling can cause wrinkles in the upper layer of cloth, affecting the bending stability of the blade trailing edge. Summary of the Invention

[0005] In view of this, the present invention aims to propose a multi-sequence UD molding method for wind turbine blades to solve the problems of the prior art in which the multi-sequence UD molding of wind turbine blades is long, has uneven sides, and cannot be quickly matched with the shell core material.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A multi-sequence UD molding method for a wind turbine blade comprises the following steps:

[0008] S1. UD mold preparation: clean the surface of the UD mold and apply a release agent on the inner surface of the UD mold;

[0009] S2. Laying a first continuous felt and a first release cloth on the UD mold in sequence;

[0010] S3, laying of a sequence of UD fabric layers;

[0011] S4. Silicone mold preparation: Position the silicone mold according to the first sequence UD cloth layer and the second sequence UD cloth layer;

[0012] S5, laying of the second sequence UD fabric layer;

[0013] S6. Connecting the silicone mold to the first sequence UD fabric layer and the second sequence UD fabric layer;

[0014] S7, vacuum establishment, pressure maintenance, infusion and curing.

[0015] The present invention uses a silicone mold and positions the silicone mold after laying a first sequence of UD cloth layers, and fixes the silicone mold when laying a second sequence of UD cloth layers. This not only achieves one-time injection molding of multiple sequences of UD, but also makes the side edges between the first sequence of UD and the second sequence of UD smoother, thereby improving the matching of the multiple sequence of UD and the shell core material molding, and improving the shell molding efficiency and quality.

[0016] Furthermore, in step S6, the following steps are specifically included:

[0017] S61, removing the silicone mold from a sequence of UD fabric layers;

[0018] S62, laying a second release cloth and a perforated isolation film, wherein the perforated isolation film is laid on the second release cloth, the second release cloth covers the first sequence UD cloth layer and the second sequence UD cloth layer, and the perforated isolation film extends from the first sequence UD cloth layer to the second sequence UD cloth layer;

[0019] S63, positioning according to step S4, placing the second continuous felt, the silicone mold and the guide net, the guide net covering the first sequence UD cloth layer and the second sequence UD cloth layer, and connecting and fixing the guide net to the second continuous felt on the lower side of the silicone mold.

[0020] This setup provides additional support for the UD fabric layers by laying a second release sheet and a flow mesh, helping to maintain their flatness during the infusion and curing process. The flow mesh extends from the first to the second UD fabric layers, ensuring even resin distribution during infusion and further minimizing side unevenness. By precisely connecting the silicone mold to the second continuous mat and the flow mesh, the shape and size of the UD fabric layers can be precisely controlled, avoiding side unevenness caused by shape deviations.

[0021] Furthermore, in step S6, the cross section of the silicone mold is a quadrilateral, the laying cross section of the first sequence of UD fabric layers is a triangle, and the laying cross section of the second sequence of UD fabric layers is a quadrilateral.

[0022] Furthermore, in step S4, the silicone mold includes a first surface, a second surface, a third surface, and a fourth surface connected in sequence, the angle between the first surface and the second surface is α2, the UD mold includes a flange surface and a bottom surface, the angle between the flange surface and the bottom surface is α1, α1=α2.

[0023] This setting ensures the flatness of the front side of the second-sequence UD, sets the height of the silicone mold and the height of the second-sequence UD cloth layer to a certain level, and ensures that the top of the UD is flush with the silicone mold without warping after pouring, thereby achieving the overall flatness of the side of the multi-sequence UD, thereby improving the matching with the shell core material and improving the shell molding efficiency and quality.

[0024] Furthermore, in step S4, when the silicone mold is positioned, a second continuous felt is placed on the lower end of the silicone mold, and the second surface is arranged on the second continuous felt.

[0025] This setup uses a silicone mold for precise positioning. On the one hand, it ensures that each sequence of UD fabric layers is laid accurately, avoiding repeated adjustments and corrections due to position deviations, thereby shortening the molding cycle. On the other hand, when the silicone mold is positioned, a second continuous felt is placed at the lower end of the silicone mold. This step provides additional support for the UD fabric layer, helping to maintain the flatness of the fabric layer during the infusion and curing process. The flexibility and elasticity of the silicone mold can adapt to the shrinkage and deformation of the UD fabric layer during the curing process, thereby reducing the unevenness of the side edges.

[0026] Furthermore, an obtuse angle formed by the surface where the second continuous felt is located and the surface where the third surface is located is α3, and α3>90°.

[0027] This setting not only prevents the bag film from failing to adhere to the silicone mold during vacuuming, causing the bag film to burst and leak, but also ensures the firmness of the silicone mold connection, making the side smoother during multi-sequence UD molding.

[0028] Furthermore, the width of the first continuous felt and the second continuous felt is 100-300 mm.

[0029] Furthermore, the first continuous felt and the second continuous felt have a gram weight of 200 to 300 g / m 2 .

[0030] Furthermore, the first sequence of UD fabric layers is laid out in 17 to 21 layers, and the second sequence of UD fabric layers is laid out in 43 to 47 layers.

[0031] Furthermore, in step S7, the vacuum degree during vacuum establishment is ≤-0.095 MPa, the pressure holding time is 5 to 15 minutes, and the vacuum degree decreases by ≤0.002 MPa.

[0032] Compared with the existing technology, the multi-sequence UD molding method for wind turbine blades described in the present invention has the following advantages:

[0033] 1) By using a silicone mold and positioning the silicone mold after laying a first-sequence UD fabric layer, and fixing the silicone mold when laying a second-sequence UD fabric layer, the present invention not only achieves one-time injection molding of multiple UD fabrics, but also makes the side edges between the first-sequence UD and the second-sequence UD more flat, thereby improving the matching of the multiple-sequence UD and the shell core material molding, and improving the shell molding efficiency and quality;

[0034] 2) In the UD mold of the present invention, the angles of the flange surface and the bottom surface are the same as those of the first surface and the second surface, ensuring the flatness of the front side of the second sequence of UDs. The height of the silicone mold and the height of the second sequence of UD fabric layers are set to a certain level to ensure that the top of the UD is flush with the silicone mold after pouring without warping, thereby achieving the overall flatness of the sides of the multi-sequence UDs, thereby improving the compatibility with the shell core material and enhancing the shell molding efficiency and quality.

[0035] 3) The obtuse angle formed by the surface where the second continuous felt is located and the surface where the third surface is located is α3, and α3>90°. This setting not only prevents the bag film from being unable to stick to the silicone mold during vacuuming and the bag film from bursting and leaking, but also ensures the firm connection of the silicone mold while making the side smoother during multi-sequence UD molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a cross-sectional view of the multi-sequence UD molding of a wind turbine blade according to the present invention;

[0037] Figure 2 Schematic diagram of the matching of UD and core material of the present invention.

[0038] 1-first exhaust pipe, 2-second release cloth, 3-UD mold, 31-flange surface, 32-bottom surface, 4-second sequence UD cloth layer, 5-first sequence UD cloth layer, 6-first continuous felt, 7-flow guide net, 8-perforated isolation membrane, 9-silicone mold, 91-first surface, 92-second surface, 93-third surface, 94-fourth surface, 10-second continuous felt, 11-second exhaust pipe, 12-shell core material, 13-first release cloth. DETAILED DESCRIPTION

[0039] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that in the description of the present invention, the terms "upper," "lower," "front," "rear," and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limiting the present invention.

[0040] A multi-sequence UD forming method for a wind turbine blade, the forming method is used to form a first-sequence UD and a second-sequence UD, comprising the following steps:

[0041] S1. UD mold preparation: clean the surface of UD mold 3 and apply release agent on the inner surface of the mold;

[0042] Specifically, the UD mold 3 includes a flange surface 31 and a bottom surface 32 . The angle formed between the flange surface and the bottom surface is α1 , and the connection point between the flange surface and the bottom surface is point a.

[0043] S2. Laying a first continuous felt 6 and a first release cloth 13 on the UD mold in sequence; the first continuous felt is laid on the bottom surface 32 .

[0044] Specifically, the distance between one end of the first continuous felt close to the flange surface and point a is 130 to 170 mm; the width of the first continuous felt 6 is 250 to 300 mm; the first continuous felt is laid on the PS surface or SS surface at R25-90m, that is, the length of the first continuous felt is 65m, R25-90m is the dimension in the length direction, and the length direction is the direction perpendicular to the cross-sectional view in the figure.

[0045] More specifically, both ends of the first continuous felt need to be thinned at R25m and R90m to prevent steps from forming and causing wrinkles in the upper UD fabric layer.

[0046] More specifically, the first release cloth 13 is laid above the first continuous felt with a width of 750 to 850 mm. The leading edge of the first release cloth extends 40 to 60 mm beyond the leading edge of the formed product. The excess portion of the trailing edge of the first release cloth is turned over to the flange surface. The release cloth is required to be laid flat and wrinkle-free.

[0047] S3, laying of a sequence of UD fabric layers 5;

[0048] Specifically, a sequence of UD fabric layers 5 totals 17 to 21 layers with a width of 200 to 300 mm. They are laid according to the start and end positions, first layer positioning data, and staggered layer requirements required by the process. The staggered layer width of the UD fabric layers is measured every five layers to ensure that the staggered layer width meets the process requirements. The cross-section of a sequence of UD fabric layers forms an obtuse triangle structure.

[0049] S4. Silicone mold preparation: Position the blades according to the first-order UD fabric layer 5 and the second-order UD fabric layer 4. Since the blades are all curved areas, a silicone mold is more suitable for shaping.

[0050] Specifically, the position of the silicone mold is set according to the width of the second-sequence UD cloth layer 4. The width of the second-sequence UD cloth layer is 200-300 mm. Positioning lines are drawn at intervals of about 0.9-1.1 m from the flange surface in the length direction, and the silicone mold is placed according to the drawn line position.

[0051] Specifically, the cross-section of the silicone mold is a quadrilateral.

[0052] More specifically, the silicone mold 9 includes a first surface 91, a second surface 92, a third surface 93, and a fourth surface 94 connected in sequence. The angle between the first surface 91 and the second surface 92 is α2, and α1=α2, to ensure that after the second sequence of UD cloth layers are laid, they are completely attached to the flange surface and the silicone mold, avoiding the problem of resin-rich sides after vacuum infusion.

[0053] Specifically, the height of the silicone mold is determined according to the thickness of the second-sequence UD fabric layer. That is, the height of the second-sequence UD fabric layer is consistent with the height of the fourth surface. Therefore, if the silicone mold is too high, the bag film will not be firmly attached during vacuuming. The corner area where the second-sequence UD fabric layer contacts the silicone mold is prone to warping after vacuum infusion. If the silicone mold is too low, the arc angle problem on the leading edge of the second-sequence UD fabric layer will still exist during vacuuming.

[0054] Specifically, when the silicone mold is positioned, a second continuous felt 10 is placed on the lower side of the silicone mold, and the second surface 92 is set on the second continuous felt 10. The rear edge of the second continuous felt 10 is aligned with the rear edge of the second surface, and the leading edge of the second continuous felt extends 10-20 mm beyond the connection between the first surface and the second surface to prevent a series of UD cloth layers at the lower end of the silicone mold from being wrapped during pouring.

[0055] Specifically, the obtuse angle formed by the surface where the second continuous felt is located and the surface where the third surface is located is α3, and α3>90°. This setting not only prevents the bag film from being unable to stick to the silicone mold during vacuuming and the bag film from bursting and leaking, but also ensures the firm connection of the silicone mold, making the side smoother during multi-sequence UD molding.

[0056] Specifically, the silicone mold needs to be pre-treated before positioning. The pre-treatment is to wrap the outer surface of the silicone mold with a layer of non-porous isolation film, and then use transparent tape to seal it. The seal must be tight to prevent resin from entering the silicone mold during vacuum infusion and reducing the service life of the silicone mold.

[0057] Preferably, the non-porous isolation membrane is made of polypropylene or polyethylene.

[0058] S5, laying of the second sequence UD fabric layer 4;

[0059] Specifically, the second-sequence UD fabric layer 4 has a total of 43 to 47 layers, a width of 200 to 300 mm, and a fabric type of UDS-1250. The second-sequence UD fabric layer is laid between the flange surface, the silicone mold, and the first-sequence UD fabric layer at the starting and ending positions according to the process requirements. The fabric layer is required to be firmly attached to the flange surface, the silicone mold, and the second-sequence UD fabric layer, and any gaps are filled with yarn to avoid resin-rich sides after vacuum infusion.

[0060] Specifically, the first continuous felt and the second continuous felt have a gram weight of 200 to 300 g / m 2 .

[0061] S6, connecting the silicone mold to the first sequence UD fabric layer and the second sequence UD fabric layer; S6 specifically includes the following steps:

[0062] S61, removing the silicone mold from a sequence of UD fabric layers; at this time, the second continuous felt is also removed accordingly;

[0063] S62. Lay a second release cloth 2 and a perforated isolation film 8. The second release cloth contacts the first release cloth on the outside of the multi-sequence UD cloth. The perforated isolation film is laid on the second release cloth. The second release cloth covers the first and second sequence UD cloth layers and extends to both ends of the first and second sequence UD cloth layers. The perforated isolation film extends from the first sequence UD cloth layer to the second sequence UD cloth layer. The distance A between the trailing edge of the perforated isolation film and the flange surface is 80 to 150 mm.

[0064] S63: Position the second continuous felt, silicone mold, and guide net 7 as in step S4. The silicone mold is placed on the second continuous felt, which is then placed on the first sequence of UD fabric layers. The guide net covers the first and second sequences of UD fabric layers, as well as the silicone mold. The guide net is then connected and secured to the second continuous felt on the underside of the silicone mold. Specifically, the second side of the silicone mold, the second continuous felt, and the first side of the silicone mold are all secured to the perforated isolation film by spraying adhesive.

[0065] Specifically, the distance A between the trailing edge of the guide mesh and the flange surface is 80-150 mm. The guide mesh extends from the upper end of a sequence of UD fabric layers to the fourth and third surfaces of the silicone mold, as well as the first sequence of UD fabric layers. The position and edge distance of the guide mesh from the PS and SS surfaces are shown in Table 1. The position refers to the length direction, and the edge distance refers to the distance from the flange surface.

[0066] Table 1

[0067]

[0068] Specifically, step S63 also includes laying a first exhaust pipe 1, a second exhaust pipe 11, a glue injection pipe (not shown in the figure), and a vacuum bag film (not shown in the figure); the first exhaust pipe and the second exhaust pipe are located on the two ends of the first release cloth and the second release cloth. The laying of the first exhaust pipe, the second exhaust pipe, the vacuum bag film, and the glue injection pipe are all existing technologies and will not be described in detail here.

[0069] S7, vacuum establishment, pressure maintenance, infusion and curing. After all the fabric layers and auxiliary materials are laid, a vacuum system is established. The vacuum degree is required to be ≤-0.095MPa. After closing the exhaust system, the pressure is maintained for 7 to 12 minutes and the vacuum degree is required to drop by ≤0.002MPa. The ambient temperature needs to be controlled between 15℃ and 35℃. After pressure maintenance, infusion and curing are carried out. First, the curing temperature is heated at 45 to 55℃ for 1.5 to 2.5 hours, and then the curing temperature is heated at 75 to 85℃ for 3.5 to 4.5 hours. Within the low-temperature curing temperature and time range, the resin is allowed to pass the exothermic peak to avoid the resin from releasing heat violently and causing wrinkles in the UD product. Heat within the high-temperature curing temperature and time range to ensure that the product meets the Tg and hardness requirements. After the product is cured, remove the surface auxiliary materials to obtain a multi-sequence UD product with smooth sides, improve the UD molding efficiency and the matching of the UD and the shell core material 12, and thus improve the shell molding efficiency and quality.

[0070] Example 1

[0071] A multi-sequence UD molding method for wind turbine blades adopts an upper and lower diversion scheme to integrally cast the multi-sequence UD blocks. During the laying process, a silicone mold purchased or manufactured in advance is used. After the first sequence UD cloth layer is laid, the silicone mold is positioned according to the width of the second sequence UD Block cloth layer above. After the silicone mold is placed, the second sequence UD cloth layer is laid between the flange surface and the silicone mold. After all UD cloth layers are laid, the silicone mold is fixed, and then the blades are cast together. The method specifically includes the following steps:

[0072] Step 1: UD mold preparation: clean the surface of the UD mold and apply a release agent on the mold surface according to the process requirements;

[0073] Specifically, the UD mold 3 includes a flange surface and a bottom surface. The angle formed by the flange surface and the bottom surface is α1, and the connection point between the flange surface and the bottom surface is point a.

[0074] Step 2: Lay a first continuous felt and a first release cloth on the UD mold in sequence; the first continuous felt is laid on the bottom surface.

[0075] Specifically, the distance between one end of the first continuous felt close to the flange surface and point a is 150 mm; the width of the first continuous felt is 300 mm; the first continuous felt is laid on the PS surface or SS surface at R25-90m, that is, the length of the first continuous felt is 65m, R25-90m is the dimension in the length direction, and the length direction is the direction perpendicular to the cross-sectional view in the figure.

[0076] More specifically, both ends of the first continuous felt need to be thinned at R25m and R90m to prevent steps from forming and causing wrinkles in the upper UD fabric layer.

[0077] More specifically, the first release cloth is laid on top of the first continuous felt with a width of 800 mm. The leading edge of the first release cloth extends 50 mm beyond the leading edge of the formed product, and the excess portion of the trailing edge of the first release cloth is turned over to the flange surface. The release cloth is required to be laid flat and wrinkle-free.

[0078] Step 3: Lay down a sequence of UD fabric layers;

[0079] Specifically, a sequence of UD fabric layers totals 19 layers, with a width of 250mm and a gram weight of 300g / m 2， Fabric type is UDS-1250, weight is 300g / m 2 ; Lay the UD fabric according to the starting and ending positions, first layer positioning data, staggered layer requirements, etc. required by the process. Measure the staggered layer width every 5 layers to ensure that the staggered layer width meets the process requirements. The cross-section of a sequence of UD fabric layers forms an obtuse triangle structure.

[0080] Step 4: Prepare the silicone mold: Position the first and second UD fabric layers. Since the blades are curved, a silicone mold is more suitable for shaping.

[0081] Specifically, the position of the silicone mold is set according to the width of the second-sequence UD cloth layer. The width of the second-sequence UD cloth layer is 250 mm. Positioning lines are drawn at intervals of about 0.9 to 1.1 m from the flange surface in the length direction, and the silicone mold is placed according to the drawn line position.

[0082] Specifically, the cross-section of the silicone mold is a quadrilateral.

[0083] More specifically, the silicone mold includes a first surface, a second surface, a third surface, and a fourth surface connected in sequence. The angle between the first surface and the second surface is α2, and α1=α2=100°, so as to ensure that after the second sequence UD cloth layer is laid, the flange surface and the silicone mold are completely adhered to, thereby avoiding the problem of resin-rich side after vacuum infusion.

[0084] Specifically, the height of the silicone mold is determined according to the thickness of the second-sequence UD fabric layer. That is, the height of the second-sequence UD fabric layer is consistent with the height of the fourth surface. Therefore, if the silicone mold is too high, the bag film will not be firmly attached during vacuuming. The corner area where the second-sequence UD fabric layer contacts the silicone mold is prone to warping after vacuum infusion. If the silicone mold is too low, the arc angle problem of the side of the leading edge of the second-sequence UD fabric layer will still exist during vacuuming.

[0085] Specifically, when positioning the silicone mold, a second continuous felt is placed at the lower end of the silicone mold, the second surface is set on the second continuous felt, the rear edge of the second continuous felt is aligned with the rear edge of the second surface, and the leading edge of the second continuous felt extends 15 mm beyond the connection between the first surface and the second surface to prevent a series of UD cloth layers at the lower end of the silicone mold from being wrapped during pouring.

[0086] Specifically, the obtuse angle formed by the surface where the second continuous felt is located and the surface where the third surface is located is α3, and α3 is 120°.

[0087] Specifically, the silicone mold needs to be pre-treated before positioning. The pre-treatment is to wrap the outer surface of the silicone mold with a layer of non-porous isolation film, and then use transparent tape to seal it. The seal must be tight to prevent resin from entering the silicone mold during vacuum infusion and reducing the service life of the silicone mold.

[0088] Preferably, the non-porous isolation membrane is made of polypropylene or polyethylene.

[0089] Step 5: Laying the second sequence of UD fabric layers;

[0090] Specifically, the second sequence UD fabric layer has a total of 45 layers, a width of 250mm, and a gram weight of 300g / m 2 The fabric type is UDS-1250. According to the process requirements, the second sequence UD fabric layer is laid between the flange surface, silicone mold, and the first sequence UD fabric layer at the starting and ending positions. The fabric layer is required to be firmly attached to the flange surface, silicone mold, and the second sequence UD fabric layer. The gap area is filled with yarn to avoid resin-rich sides after vacuum infusion.

[0091] Step 6: Connect the silicone mold to the first and second UD fabric layers. Step 6 specifically includes the following steps:

[0092] a. Remove the silicone mold from a sequence of UD fabric layers; at this time, the second continuous felt is also removed accordingly;

[0093] b. Lay a second release cloth and a perforated isolation film 8. The second release cloth contacts the first release cloth on the outside of the multi-sequence UD cloth. The perforated isolation film 8 is laid on the second release cloth. The second release cloth covers the first and second sequence UD cloth layers and extends to both ends of the first and second sequence UD cloth layers. The perforated isolation film extends from the first sequence UD cloth layer to the second sequence UD cloth layer. The distance A between the trailing edge of the perforated isolation film and the flange surface is 100 mm.

[0094] c. Position according to step 4, place the second continuous felt, silicone mold, and guide net. The silicone mold is placed on the second continuous felt, and the second continuous felt is placed on the first sequence of UD cloth layers. The guide net covers the first sequence of UD cloth layers and the second sequence of UD cloth layers, as well as the silicone mold. Connect and fix the guide net to the second continuous felt on the lower side of the silicone mold. Specifically, the second side of the silicone mold, the second continuous felt, the first side of the silicone mold, and the perforated isolation membrane are fixed together by spraying glue.

[0095] Specifically, the distance between the trailing edge of the guide net and the flange surface is A, and the value of A is 100 mm. The guide net extends from the upper end of a sequence of UD cloth layers to the fourth surface, the third surface, and a sequence of UD cloth layers of the silicone mold.

[0096] Specifically, step c also includes laying a first exhaust pipe 1, a second exhaust pipe 11, a glue injection pipe (not shown in the figure), and a vacuum bag film (not shown in the figure); wherein, the first exhaust pipe and the second exhaust pipe are located on the two ends of the first release cloth and the second release cloth, and the laying of the first exhaust pipe, the second exhaust pipe, the vacuum bag film, and the glue injection pipe are all existing technologies and will not be described in detail here.

[0097] Specifically, the sequence of UD cloth layers, the sequence of UD cloth layers, the first release cloth, the second release cloth, the first continuous felt, and the second continuous felt are made of conventional materials, wherein the first release cloth and the second release cloth are made of nylon 6.

[0098] Step 7: Vacuum establishment, pressure maintenance, and infusion curing. After all fabric layers and auxiliary materials are laid, a vacuum system is established with a vacuum degree of ≤-0.095MPa. After closing the exhaust system and maintaining the pressure for 10 minutes, the vacuum degree must drop by ≤0.002MPa. The ambient temperature must be controlled at 25°C. After maintaining the pressure, infusion curing is performed. The curing temperature is first set at 50°C for 2 hours, and then heated at 80°C for 4 hours. After the product is cured, the surface auxiliary materials are removed to obtain a multi-sequence UD product with smooth sides, which improves the UD molding efficiency and the matching between the UD and the shell core material, thereby improving the shell molding efficiency and quality.

[0099] Specifically, the resin used for the infusion is 190 / 195 resin produced by Daosheng Tianhe.

[0100] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A multi-sequence UD molding method for wind turbine blades, characterized in that: The following steps are involved: S1. UD mold preparation: clean the surface of the UD mold and apply a release agent on the inner surface of the UD mold; S2. Laying a first continuous felt and a first release cloth on the UD mold in sequence; S3, laying of a sequence of UD fabric layers; S4. Silicone mold preparation: Position the silicone mold according to the first sequence UD cloth layer and the second sequence UD cloth layer; S5, laying of the second sequence UD fabric layer; S6. Connecting the silicone mold to the first sequence UD fabric layer and the second sequence UD fabric layer; S7, vacuum establishment, pressure maintenance, infusion and curing; In step S4, when the silicone mold is positioned, a second continuous felt is placed on the lower end of the silicone mold; In step S6, the following steps are specifically included: S61, removing the silicone mold from a sequence of UD fabric layers; S62, laying a second release cloth and a perforated isolation film, wherein the perforated isolation film is laid on the second release cloth, the second release cloth covers the first sequence UD cloth layer and the second sequence UD cloth layer, and the perforated isolation film extends from the first sequence UD cloth layer to the second sequence UD cloth layer; S63, positioning according to step S4, placing the second continuous felt, the silicone mold and the guide net, the guide net covering the first sequence UD cloth layer and the second sequence UD cloth layer, and connecting and fixing the guide net to the second continuous felt on the lower side of the silicone mold.

2. A multi-sequence UD molding method for wind turbine blades according to claim 1, characterized in that: In step S6, the cross section of the silicone mold is a quadrilateral, the cross section of the first sequence of UD fabric layers is a triangle, and the cross section of the second sequence of UD fabric layers is a quadrilateral.

3. The multi-sequence UD molding method for wind turbine blades according to claim 1, characterized in that: In step S4, the silicone mold includes a first surface, a second surface, a third surface, and a fourth surface connected in sequence, the angle between the first surface and the second surface is α2, the UD mold includes a flange surface and a bottom surface, the angle between the flange surface and the bottom surface is α1, α1=α2.

4. The multi-sequence UD molding method for wind turbine blades according to claim 3, characterized in that: The second side is disposed on a second continuous mat.

5. The multi-sequence UD molding method for wind turbine blades according to claim 3, characterized in that: An obtuse angle formed by the surface where the second continuous felt is located and the surface where the third surface is located is α3, and α3>90°.

6. The multi-sequence UD molding method for wind turbine blades according to claim 1, characterized in that: The width of the first continuous felt and the second continuous felt is 100-300 mm.

7. The multi-sequence UD molding method for wind turbine blades according to claim 1, characterized in that: The first continuous felt and the second continuous felt have a gram weight of 200 to 300 g / m 2 .

8. The multi-sequence UD molding method for wind turbine blades according to claim 1, characterized in that: The first sequence of UD fabric layers is laid in 17 to 21 layers, and the second sequence of UD fabric layers is laid in 43 to 47 layers.

9. The multi-sequence UD molding method for wind turbine blades according to claim 1, characterized in that: In step S7 , the vacuum degree during vacuum establishment is ≤-0.095 MPa, the pressure holding time is 5 to 15 minutes, and the vacuum degree decreases by ≤0.002 MPa.

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