A wind turbine blade skin fabric weaving process and a fabric prepared by the same

Abstract

The present application relates to the wind power blade manufacturing technical field, aiming at the problem that the polyester filament is exposed after the existing wind power blade skin outer surface is polished, and the traces are obvious after the putty is coated, a wind power blade skin fabric weaving process and the fabric prepared by the process are provided, including the following steps: S1, taking no-alkali glass fiber as yarn, the yarn is woven to form a glass fiber fabric base material with a multi-layer symmetrical layer structure, the multi-layer symmetrical layer structure includes +45° layer and -45° layer; S2, using polyester filament warp knitting sewing process, the glass fiber surface felt is sewn on the surface of the +45° layer of the glass fiber fabric base material; S3, taking 5-15 tex fine denier polyester filament as sewing yarn, and controlling the weaving tension of the sewing yarn during sewing to be 8-16 N; S4, using cross-laying weft method to lay weft, controlling the sewing density of the polyester filament to be 5-7 needles / inch, sewing, and preparing the glass fiber fabric.

Description

Technical Field

[0001] This invention relates to the field of wind turbine blade manufacturing technology, and more specifically, to a weaving process for wind turbine blade skin fabric and the fabric obtained therefrom. Background Technology

[0002] As a core component of wind turbine generators, wind turbine blades typically use a composite molding process of fiberglass fabric and resin for their skin. To improve the smoothness and anti-aging properties of the blade surface, a surface felt needs to be laid on the outer surface of the skin, followed by subsequent treatments such as sanding and puttying. In existing wind turbine blade skins, the stitching process of the surface felt is generally limited by the weaving equipment. The surface felt is usually stitched to the -45° layer of the fiberglass fabric, while the polyester yarn used for stitching adopts a warp-knitted loop structure, forming a double-strand loop in the -45° layer. This double-strand loop is easily worn through during the skin sanding process, resulting in the exposure of the polyester yarn. At the same time, the polyester yarn used in the current process has a large yarn count and insufficient weaving tension, causing the polyester yarn to float on the fabric surface, further aggravating the problem of exposed polyester yarn after sanding. In addition, the low stitching density of the polyester yarn and the single yarn layup method result in insufficient resin absorption on the outer surface of the fabric, and obvious fabric texture marks still exist after applying putty, requiring secondary repairs. This not only increases production costs but also affects the production efficiency and appearance quality of the blade.

[0003] To address the aforementioned issues, existing technologies often compensate for defects by increasing the number of sanding passes or thickening the putty layer. However, these methods cannot fundamentally solve the problems of exposed polyester fibers and fabric texture marks, and they also lead to increased blade weight and extended production cycles. Therefore, there is an urgent need to develop a fiberglass fabric production process that can improve fabric texture defects after blade skin sanding from the source of the process. Summary of the Invention

[0004] The purpose of this invention is to provide a weaving process for wind turbine blade skin fabric and the fabric prepared therefrom, so as to solve the technical problems of exposed polyester filaments after sanding the outer surface of existing wind turbine blade skin and obvious traces after applying putty.

[0005] This invention is achieved through the following technical solution: A weaving process for wind turbine blade skin fabric includes the following steps: (1) Preparation of glass fiber fabric substrate: Alkali-free glass fiber is selected as the yarn. Alkali-free glass fiber has excellent mechanical properties and corrosion resistance, ensuring the structural strength of the fabric substrate.

[0006] A fiberglass fabric substrate is woven from yarns to form a multi-layered symmetrical layup structure containing +45° and -45° layers, with 3 to 5 layers. The +45° and -45° layers are alternately distributed. The warp density and weft density of each layer are controlled at 25 yarns / cm or higher, and the fabric area mass is controlled at 600 to 1200 g / m². 2 This ensures the overall stability and mechanical balance of the substrate.

[0007] (2) Surface felt stitching: Using polyester warp knitting and stitch knitting techniques, yarns with a weight of 25~35g / m² are knitted. 2 The fiberglass surface mat is sewn onto the +45° layer surface of the fiberglass fabric substrate.

[0008] Due to the characteristics of the warp-knitted coil structure of polyester yarn, a single-strand coil structure will naturally form in the +45° layer. Compared with the double-strand coil in the -45° layer, the single-strand coil structure is more compact and less prone to damage during polishing, thus preventing the polyester yarn from being exposed.

[0009] During sewing, the puncture depth of the polyester filament should be controlled to 1 / 2 to 2 / 3 of the thickness of the fiberglass fabric substrate to ensure a firm bond between the surface felt and the substrate, while avoiding excessive penetration of the polyester filament into the substrate that could affect resin impregnation.

[0010] (3) Prepare the yarn for sewing: Fine denier polyester yarn of 5~15tex is selected as the stitching yarn, as finer polyester yarn is easier to embed into the fabric; at the same time, the breaking strength of the stitching yarn is required to be ≥5.5cN / dtex, and the breaking elongation is 15~20% to ensure that it is not easy to break during the stitching process.

[0011] During the stitching process using this fine denier polyester yarn, the weaving tension is controlled at 8~16N. Under the action of tension, the polyester yarn will be tightly embedded in the gaps between the yarns of the fiberglass fabric, away from the surface of the fabric, further avoiding contact with the polyester yarn during sanding.

[0012] (4) Laying weft and stitching: The weft yarns are laid using a cross-laying method with an angle of 30° to 60°, which creates interlaced flow channels on the fabric surface, facilitating rapid resin penetration and uniform distribution on the skin surface. At the same time, the stitching density of the polyester yarns is controlled at 5 to 7 stitches / inch to increase the bonding points between the surface felt and the substrate, thereby improving the structural density of the fabric surface.

[0013] The combination of cross-lay weft and high-density stitching can increase the resin absorption of the fabric's outer surface to 350g / m². 2 This process forms a thick protective resin layer that covers the yarn texture inside the fabric.

[0014] Preferably, the glass fiber surface mat in this invention is a microporous ultrafine glass fiber surface mat, and the preparation method of the microporous ultrafine glass fiber surface mat includes the following steps: (1) By mass fraction, 75~85wt% of 0.5~1.2dtex ultrafine denier glass fiber is mixed with 15~25wt% of low melting point bonding glass fiber. Specifically, commercially available 120℃ low temperature melt core-sheath structure bonding glass fiber can be used. Multi-stage opening is carried out at an opening speed of 800~1200r / min and a mixing time of 5~10min until the mixture is uniform and there are no lumps, so as to completely eliminate fiber agglomeration and clumping and ensure the uniformity of subsequent molding.

[0015] (2) After multi-stage opening, the mixture is put into a wet molding dispersion tank, and 0.3~0.8wt% aminosilane coupling agent, 0.1~0.3wt% dispersant and deionized water are added. The mixture is dispersed at 1500~2500r / min for 3~8min to obtain a uniform fiber slurry with a mass concentration of 0.5~1.5‰. In this process, the aminosilane coupling agent can effectively improve the wetting and bonding performance of glass fiber and resin and improve the compatibility of glass fiber interface.

[0016] (3) Feed the uniform fiber slurry into the inclined wire mesh wet forming machine, control the wire mesh speed to be 5~15m / min, the vacuum dehydration degree to be -0.02 to -0.06MPa, and form a forming surface density of 25~35g / m 2 The fiberglass mesh has a uniformity deviation of ≤±3%, ensuring that the entire felt material has uniform thickness and consistent pore distribution.

[0017] (4) Dry the fiber web at 90~110℃ for 1~3 minutes to quickly remove free water, preserve the microporous structure of the glass fiber, and avoid pore blockage. Then, in a pressureless or low-pressure environment, use hot air at 110~130℃ and 1.2~2.0m / s to penetrate and bond the dried fiber web for 30~60 seconds. Only the fiber nodes are bonded, which ensures that the pore structure does not collapse or close, and forms uniform dot-like bonding points. It will not form a continuous hard film, thus ensuring the flexibility and breathability of the felt material. Finally, it is cooled by a 25~35℃ roller and wound up smoothly with a tension of 20~50N to form a microporous ultrafine glass fiber surface felt with a thickness of about 0.10~0.20mm.

[0018] The microporous ultrafine glass fiber surface mat prepared by the above method has high resin absorption, low glass fiber exposure rate after sanding, and low surface flatness deviation after puttying. It has the characteristics of good resin wettability, fine surface, high flatness and strong weather resistance, and can fully meet the requirements of wind turbine blade skin for corrosion prevention, leveling and seepage prevention.

[0019] The technical solution of the present invention has at least the following advantages and beneficial effects: (1) The present invention stitches the surface felt to the +45° layer and uses the single-strand coil structure formed by polyester yarn in this layer to solve the problem of polyester yarn exposure caused by easy breakage of the double-strand coil in the traditional -45° layer, thus eliminating the root cause of fabric texture defects from a structural perspective.

[0020] (2) By using fine polyester yarn and increasing the weaving tension, the polyester yarn is embedded in the fabric, preventing it from floating on the surface and being exposed by grinding, while ensuring the stitch strength of the fabric.

[0021] (3) The combination of cross-weft design and high-density stitching process not only increases the amount of resin absorbed by the fabric surface, forming a thick protective resin layer to cover the yarn texture, but also optimizes the resin impregnation effect and reduces molding defects.

[0022] (4) This process does not require any new special equipment. It can be achieved simply by adjusting the existing weaving parameters. It has low production costs and is easy to promote industrially. It can significantly reduce the later maintenance costs of blade skin and improve production efficiency and product quality. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, they are performed according to conventional conditions or conditions recommended by the manufacturer; where the manufacturers of the instruments, equipment, reagents, or raw materials used are not specified, they are all conventional products that can be purchased commercially.

[0024] Example 1

[0025] (1) Preparation of glass fiber fabric substrate: alkali-free glass fiber is selected as yarn and woven into 4 layers of glass fiber fabric substrate, including 2 layers of +45° layer and 2 layers of -45° layer, with each layer having a warp density of 27 yarns / cm and a weft density of 25 yarns / cm. (2) Surface felt stitching: Polyester yarn warp knitting stitching process is used to stitch 30g / m 2 The microporous ultrafine glass fiber surface mat is stitched onto the +45° layer surface, and the polyester filament puncture depth is 1 / 2 of the substrate thickness. (3) Prepare the sewing yarn: Select 10tex polyester yarn as the sewing yarn. Its breaking strength is 5.8cN / dtex and its breaking elongation is 18%. Control the weaving tension to 10N during sewing. (4) Weft laying and stitching: Weft yarns are laid using a 45° cross weft laying method, with an interlacing spacing of 6mm between adjacent weft yarns; the stitching density of polyester yarns is adjusted to 6 stitches / Inch, and finally the wind turbine blade skin fabric is obtained.

[0026] The performance of the prepared wind turbine blade skin fabric was tested: the resin absorption of the surface layer of the fiberglass fabric was measured to be 380 g / m² using the immersion weighing method. 2 After the blade skin is shaped and polished (polishing thickness is about 0.3mm), 10 10cm×10cm areas are randomly selected, the number of exposed filaments is counted, and the polyester filament exposure rate is calculated to be 0.3%. Using a ruler and feeler gauge, the maximum height deviation of the surface flatness after applying putty within 1m is measured to be 0.2mm / m, with no obvious fabric texture marks, which meets the usage requirements.

[0027] Example 2

[0028] The difference between this embodiment and Embodiment 1 is that the process parameters and conditions use the smaller values ​​within the range. Specifically: (1) Preparation of glass fiber fabric substrate: alkali-free glass fiber is selected as yarn and woven into 3 layers of glass fiber fabric substrate, including 1 +45° layer and 2 -45° layers distributed alternately, with a warp density of 25 yarns / cm and a weft density of 25 yarns / cm in each layer; (2) Surface felt stitching: Polyester yarn warp knitting stitching process is used to stitch 25g / m² yarn. 2 The microporous ultrafine glass fiber surface mat is stitched onto the +45° layer surface, and the polyester filament puncture depth is 2 / 3 of the substrate thickness. (3) Prepare the sewing yarn: Select 5tex polyester yarn as the sewing yarn, with a breaking strength of 5.5cN / dtex and a breaking elongation of 15%. Control the weaving tension to 8N during sewing. (4) Weft laying and stitching: Weft yarns are laid using a 30° cross weft laying method, with an interlacing spacing of 5mm between adjacent weft yarns; the stitching density of polyester yarns is adjusted to 6 stitches / Inch, and finally the wind turbine blade skin fabric is obtained.

[0029] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: surface resin absorption was 350 g / m². 2 The exposed polyester filament rate is 0.5%, the surface flatness deviation after applying putty is 0.3mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0030] Example 3

[0031] The difference between this embodiment and Embodiment 1 is that the process parameters and conditions use the larger values ​​within the range. Specifically: (1) Preparation of glass fiber fabric substrate: alkali-free glass fiber is selected as yarn and woven into 5 layers of glass fiber fabric substrate, including 3 layers of +45° layer and 2 layers of -45° layer, with each layer having a warp density of 30 yarns / cm and a weft density of 27 yarns / cm. (2) Surface felt stitching: Polyester yarn warp knitting stitching process is used to stitch 35g / m² yarn.2 The microporous ultrafine glass fiber surface mat is stitched onto the +45° layer surface, and the polyester filament puncture depth is 1 / 2 of the substrate thickness. (3) Prepare the sewing yarn: Select polyester yarn with a number of 15tex as the sewing yarn. Its breaking strength is 6.0cN / dtex and its breaking elongation is 20%. Control the weaving tension to 12N during sewing. (4) Weft laying and stitching: Weft yarns are laid using a 60° cross weft laying method, with an 8mm spacing between adjacent weft yarns; the stitching density of polyester yarns is adjusted to 7 stitches / Inch, and finally the wind turbine blade skin fabric is obtained.

[0032] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: the surface resin absorption was 420 g / m². 2 The exposed polyester filament rate is 0.1%, the surface flatness deviation after applying putty is 0.1mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0033] Example 4

[0034] The only difference between this embodiment and Embodiment 1 is that the stitching yarn used is 5tex polyester yarn.

[0035] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: the surface resin absorption was 390 g / m². 2 The exposed polyester filament rate is 0.2%, the surface flatness deviation after applying putty is 0.15mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0036] Example 5

[0037] The only difference between this embodiment and Embodiment 1 is that the stitching yarn used is 15tex polyester yarn.

[0038] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: the surface resin absorption was 370 g / m². 2 The exposed polyester filament rate is 0.4%, the surface flatness deviation after applying putty is 0.25mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0039] Example 6

[0040] The only difference between this embodiment and Embodiment 1 is that the weaving tension is controlled to be 8N during stitching.

[0041] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: the surface resin absorption was 375 g / m². 2The exposed polyester filament rate is 0.4%, the surface flatness deviation after applying putty is 0.25mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0042] Example 7

[0043] The only difference between this embodiment and Embodiment 1 is that the weaving tension is controlled at 16N during stitching.

[0044] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: the surface resin absorption was 385 g / m². 2 The exposed polyester filament rate is 0.2%, the surface flatness deviation after applying putty is 0.15mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0045] Example 8

[0046] The only difference between this embodiment and Embodiment 1 is that the weft yarn is laid using a 30° cross-laying method.

[0047] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: the surface resin absorption was 365 g / m². 2 The exposed polyester filament rate is 0.3%, the surface flatness deviation after applying putty is 0.3mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0048] Example 9

[0049] The only difference between this embodiment and Embodiment 1 is that the weft yarn is laid using a 60° cross-laying method.

[0050] The wind turbine blade skin fabric was tested using the same performance testing method as in Example 1: the surface resin absorption was 395 g / m². 2 The exposed polyester filament rate is 0.25%, the surface flatness deviation after applying putty is 0.2mm / m, and there are no obvious fabric texture marks, which meets the usage requirements.

[0051] Comparative Example 1 The only difference between this comparative example and Example 1 is that: conventional ultra-fine denier glass fiber surface mat is sewn onto a -45° layer, polyester yarn number is 45tex, weaving tension is 5N, parallel weft laying is used, and the stitch density is 5 stitches / Inch.

[0052] The fabric was tested using the same performance testing method as in Example 1: surface resin absorption was 280 g / m². 2 The exposed polyester filament rate was 8.5%, and the surface flatness deviation after applying putty was 1.2 mm / m, with obvious fabric texture marks.

[0053] Comparative Example 2 The only difference between this comparative example and Example 1 is that conventional ultra-fine denier glass fiber surface mat is sewn onto the -45° layer.

[0054] The fabric was tested using the same performance testing method as in Example 1: surface resin absorption was 275 g / m². 2 The exposed polyester filament rate is 8.2%, the surface flatness deviation after applying putty is 1.3mm / m, and the fabric texture is obvious.

[0055] Comparative Example 3 The only difference between this comparative example and Example 1 is that the polyester yarn count is 45 tex and the weaving tension is 5 N.

[0056] The fabric was tested using the same performance testing method as in Example 1: surface resin absorption was 280 g / m². 2 The exposed polyester filament rate is 6.7%, and the surface flatness deviation after applying putty is 1.2 mm / m, with severe surface unevenness.

[0057] Comparative Example 4 The only difference between this comparative example and Example 1 is that parallel weft laying is used and the stitch density is 5 stitches / Inch.

[0058] The fabric was tested using the same performance testing method as in Example 1: surface resin absorption was 290 g / m². 2 The exposed polyester filament rate was 3.1%, the surface flatness deviation after applying putty was 0.9 mm / m, and the putty coverage was difficult.

[0059] Comparative Example 5 The only difference between this comparative example and Example 1 is that the surface felt is not sewn together.

[0060] The fabric texture obtained in this comparative example is extremely obvious and cannot be used directly.

[0061] The comparative experiments of Examples 1-9 and Comparative Examples 1-5 show that the fiberglass fabrics prepared using the production process proposed in this invention in Examples 1-9 have significantly higher surface resin absorption than the fabrics in Comparative Examples 1-5. Furthermore, the polyester filament exposure rate after polishing and the surface smoothness deviation after puttying are significantly lower than those in Comparative Examples 1-5. This demonstrates that the production process proposed in this invention, through improvements to the process methods and conditions, can significantly improve the fabric texture defects after polishing the blade skin, exhibiting clear performance advantages.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A weaving process for wind turbine blade skin fabric, characterized in that, Includes the following steps: S1 uses alkali-free glass fiber as yarn, and the yarn is woven into a multi-layer symmetrical ply structure glass fiber fabric substrate, which includes a +45° layer and a -45° layer. S2 uses a polyester warp-knitting and stitching process to stitch the fiberglass surface mat onto the +45° layer surface of the fiberglass fabric substrate; S3 uses 5~15tex fine denier polyester yarn as stitch-knitting yarn, and controls the weaving tension of the stitch-knitting yarn to be 8~16N during stitch-knitting. S4 uses a cross-laying method to lay the weft yarns, and controls the stitching density of the polyester yarns to be 5~7 stitches / Inch, and then stitches to produce fiberglass fabric.

2. The weaving process of wind turbine blade skin fabric according to claim 1, characterized in that, In S1, the warp density of each layer is controlled at 20-25 yarns / cm, and the weft density is controlled at 18-22 yarns / cm.

3. The weaving process of wind turbine blade skin fabric according to claim 1, characterized in that, In S2, the puncture depth of the polyester filament is controlled to be 1 / 2 to 2 / 3 of the thickness of the fiberglass fabric substrate.

4. The weaving process of wind turbine blade skin fabric according to claim 1, characterized in that, In S3, the breaking strength of the stitch-woven yarn is ≥5.5cN / dtex, and the breaking elongation is 15~20%.

5. The weaving process for wind turbine blade skin fabric according to claim 1, characterized in that, In S4, the angle of the cross-laying weft is 30°~60°, and the spacing between adjacent weft yarns is 5~8mm.

6. A fabric, characterized in that, It is prepared using the weaving process of wind turbine blade skin fabric as described in any one of claims 1 to 5.

7. The fabric according to claim 6, characterized in that, The surface resin absorption of the fabric is ≥350g / m². 2 After sanding, the exposed polyester filament rate is ≤0.5%, and the surface flatness deviation after applying putty is ≤0.3mm / m.