A multi-layer stitched and hoop-lay E8-t650 fabric and a method of making the same

Abstract

The present application relates to the technical field of glass fiber products, and provides an E8-T650 fabric for multi-layer stitching and hoop laying and a preparation method thereof in view of the problems existing in the application of the existing glass fiber fabric in large blade efficient laying and the like, which comprises 90-degree main reinforcing yarn, 0-degree flow guide reinforcing yarn and binding stitching yarn, the 90-degree main reinforcing yarn adopts E8 glass fiber yarn, the 0-degree flow guide reinforcing yarn adopts E6 glass fiber yarn, and the 90-degree main stress layer and the 0-degree equidistant flow guide layer are in a biaxial asymmetric structure. Through the optimization design of the fabric raw material, structure and the like, the present application can reduce the lap deviation, so that it can be effectively applied to the efficient laying demand of the large blade, and the fabric material with abnormal lap points is reduced, so as to effectively reduce the probability of the mismatch between the blade stress and the material performance, thereby improving the quality safety of the wind power blade.

Description

Technical Field

[0001] This invention relates to the field of glass fiber products technology, and more specifically, to a multi-layer stitch-woven and circumferentially laid E8-T650 fabric and its preparation method. Background Technology

[0002] As the core component that converts wind energy into electrical energy, the performance of wind turbine blades directly determines the power generation efficiency, operation and maintenance costs, and overall life-cycle benefits of wind turbines. They represent a key breakthrough for the wind power industry to achieve cost reduction and efficiency improvement. Driven by a promising market outlook, wind turbine blade technology continues to advance, exhibiting a trend towards larger and lighter designs.

[0003] Fiberglass uniaxial fabric is a primary material in wind turbine blade manufacturing. As blade length continues to increase, the number of fabric pieces required for design also increases. Currently, wind turbine blade production still heavily relies on manual layup operations. On the one hand, the increased number of pieces limits production efficiency; on the other hand, given that overlap control during blade layup primarily depends on on-site personnel, traditional uniaxial fabric is prone to overlap deviations during circumferential layup. Such deviations can lead to stress concentration in localized areas, reduced structural continuity, weakened strength, and even, in extreme cases, deviations from the correct fabric distribution designed for the blade, resulting in a mismatch between the overall stress state and material properties. This will significantly reduce blade lifespan and power generation efficiency, and substantially increase the quality risks of wind turbine blades.

[0004] Based on the above situation, there is an urgent need to develop a fabric material that can meet the high-efficiency layup requirements of large blades and reduce the occurrence of abnormal overlap points, so as to effectively reduce the probability of mismatch between blade stress and material performance, thereby improving the quality and safety of wind turbine blades. Summary of the Invention

[0005] The purpose of this invention is to provide an E8-T650 fabric for multi-layer stitching and circumferential layup and its preparation method, so as to meet the high-efficiency layup requirements of large blades.

[0006] This invention is achieved through the following technical solution: The present invention provides an E8-T650 fabric for multi-layer stitch-knitting and circumferential lay-up, comprising a 90° main reinforcing yarn, a 0° flow-guiding reinforcing yarn and a binding stitch-knitting yarn, wherein the 90° main stress layer and the 0° equidistant flow-guiding layer form a biaxial asymmetric structure.

[0007] Preferably, the 90° main reinforcing yarn is made of E8 glass fiber yarn, preferably E8DR17-600-390 specification yarn, and the unit area mass of the 90° main reinforcing yarn is controlled at (598±3%) g / m². 2 With a Young's modulus ≥ 95 GPa, it is used as the main load-bearing yarn.

[0008] Preferably, the 0° flow-guiding reinforcing yarn is made of E6 glass fiber yarn, preferably E6DR16-200-390 specification yarn, and the unit area mass of the 0° flow-guiding reinforcing yarn is controlled at (42±2%) g / m. 2 This is used to form a directional flow channel of equal width.

[0009] Preferably, the binding and stitching yarn is made of 100D high-shrinkage, low-elasticity polyester yarn, and the unit area mass of the binding and stitching yarn is controlled at (6±2%) g / m. 2 High-shrinkage polyester yarn is used for binding, making the product dimensions more stable.

[0010] The total weight of the E8-T650 fabric proposed in this invention is controlled at (646±3%) g / m³. 2 .

[0011] This invention optimizes and improves the preparation process, etc., so that the 0° yarn has equally spaced protrusions, forming a continuous through resin flow channel.

[0012] The present invention also provides a method for preparing the above-mentioned multi-layer stitch-knitted and circumferentially laid E8-T650 fabric, comprising the following steps: (1) Dehumidification and activation treatment of raw yarn: The 90° main reinforcing yarn and the 0° guide reinforcing yarn are respectively sent into a dehumidification activation chamber and treated for 30-50 minutes at 70-80℃ and -0.05MPa to -0.01MPa until their moisture content drops below 0.02% to improve the subsequent impregnation effect and dimensional stability.

[0013] (2) Graded tension warping: Segmented tension compensation is adopted to control the tension of the 90° main reinforcing yarn at 220-240 cN / yarn and constant tension weft feeding, while the tension of the 0° guiding reinforcing yarn is 90-110 cN / yarn and tension fluctuation is ≤±3%, thus avoiding yarn slack.

[0014] (3) Tension-adaptive parallel weft laying: By adopting the tension-adaptive parallel weft laying method, the 90° main reinforcing yarn is laid in parallel, and the weft laying speed is controlled at 9-11m / min. The weft laying accuracy is maintained at ≤±2% of the weight fluctuation, which can keep the 90° main reinforcing yarn without crossing, overlapping, or bending.

[0015] (4) 0° flow-guiding and reinforcing yarns are laid out at equal intervals: The 0° guiding and reinforcing yarn is laid at equal intervals of 3.5±0.2mm to form a continuous and through fixed-width guiding channel, and the flatness is controlled to ensure that the local protrusion is ≤0.8mm.

[0016] (5) High-shrinkage stitch binding: The control stitching structure is warp-flat Tricot (1-0 / 2-3 / / ), the stitching density is 4-8 ends / inch, the stitch length is 2.5-3.0 mm, the binding tension of the stitching yarn is 20-30 cN, and the stitching speed is 7-9 m / min for stitching binding.

[0017] (6) Gradient thermal shaping: The material is placed in different temperature zones for heat setting treatment. Specifically, the temperature zones can be set to 80-90℃, 90-100℃, and 70-90℃, with a total heat setting time of 20-25 seconds. Through heat setting treatment, the internal stress can be released layer by layer, and the width deviation can be controlled within ≤±3mm.

[0018] (7) Air cooling, setting, winding, and slitting: The product is shaped using air cooling at ≤40℃, and then undergoes comprehensive online inspection of weight, width, and stitch defects to automatically remove defective products. It is then wound up and slit under constant tension of 180-220N, with slit accuracy controlled within ≤±1mm, and stored in sealed packaging.

[0019] The technical solution of the present invention has at least the following advantages and beneficial effects: By optimizing the fabric structure, the E8-T650 fabric can meet the high-efficiency layup requirements of large blades, reduce the fabric material at abnormal overlap points, and effectively reduce the probability of mismatch between blade stress and material performance, thereby improving the quality and safety of wind turbine blades. While facilitating on-site installation, it also has reliable mechanical properties and excellent resin impregnation efficiency, meeting the requirements of current blade size development for production efficiency and precise distribution of layup structure. Attached Figure Description

[0020] Figure 1 This is a photograph of the E8-T650 fabric used in Example 1; Figure 2 This is a photograph of a standard uniaxial E8 fiberglass fabric from Comparative Example 1. Detailed Implementation

[0021] 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.

[0022] Example 1

[0023] E8DR17-600-390 yarn was used as the 90° main reinforcing yarn, and E6DR16-200-390 yarn was used as the 0° flow-guiding reinforcing yarn. Both were placed in an environment of 75℃ and -0.03MPa for 40 minutes for dehumidification activation. The 0° flow-guiding reinforcing yarn was warped at 100cN, and the 90° main reinforcing yarn was weft-stored at 230cN. Parallel weft laying was performed at 10m / min. The weight of the 90° main reinforcing yarn was approximately 598g / m². 2 The 0° flow-guiding reinforcing yarn is laid out at equal intervals of 3.5mm, and the weight of the 0° flow-guiding reinforcing yarn is approximately 42g / m². 2 Using 100D high-shrinkage polyester yarn, the fabric is woven with a flat (1-0 / 2-3 / / ) warp thread, 6 ends / inch, and 2.8mm stitches. It is then heat-set at gradient temperatures of 85℃, 95℃, and 80℃ for 6s, 12s, and 4s respectively, followed by air cooling to below 40℃. Finally, it is wound and slit under constant tension of 200N, with slit accuracy controlled within ±1mm, resulting in E8-T650 fabric. The actual product is shown below. Figure 1 As shown.

[0024] The total weight of the E8-T650 fabric prepared in this example was measured to be 646 g / m². 2 .

[0025] Example 2

[0026] E8DR17-600-390 yarn was used as the 90° main reinforcing yarn, and E6DR16-200-390 yarn was used as the 0° flow-guiding reinforcing yarn. Both were placed in an environment of 70℃ and -0.05MPa for 30 minutes for dehumidification and activation. The 0° flow-guiding reinforcing yarn was warped at 90cN, and the 90° main reinforcing yarn was weft-stored at 220cN. Parallel weft laying was performed at 9m / min. The weight of the 90° main reinforcing yarn was approximately 598g / m². 2 The 0° flow-guiding reinforcing yarn is laid out at equal intervals of 3.3mm, and the weight of the 0° flow-guiding reinforcing yarn is approximately 42g / m². 2 ; 100D high-shrinkage polyester yarn is used, and it is sewn with a flat (1-0 / 2-3 / / ) stitch, 5 ends / inch, and 2.5mm stitches; then it is heat-set in sequence at a gradient temperature of 80℃, 90℃, and 70℃ for 6s, 10s, and 4s respectively, and then air-cooled to below 40℃. It is then wound and cut with a constant tension of 200N, and the cutting accuracy is controlled within ±1mm to obtain E8-T650 fabric.

[0027] The total weight of the E8-T650 fabric prepared in this example was measured to be 644 g / m². 2 .

[0028] Example 3

[0029] E8DR17-600-390 yarn was used as the 90° main reinforcing yarn, and E6DR16-200-390 yarn was used as the 0° flow-guiding reinforcing yarn. Both were placed in an environment of 80℃ and -0.01MPa for 50 minutes for dehumidification activation. The 0° flow-guiding reinforcing yarn was warped at 110cN, and the 90° main reinforcing yarn was weft-stored at 240cN. Parallel weft laying was performed at 11m / min. The weight of the 90° main reinforcing yarn was approximately 598g / m². 2 The 0° flow-guiding reinforcing yarn is laid out at equal intervals of 3.7mm, and the weight of the 0° flow-guiding reinforcing yarn is approximately 42g / m². 2 ; 100D high-shrinkage polyester yarn is used, and it is sewn with a flat (1-0 / 2-3 / / ) stitch, 8 ends / inch, and 3.0mm stitches; then it is heat-set at a gradient temperature of 90℃, 100℃, and 90℃ for 8s, 13s, and 4s respectively, and then air-cooled to below 40℃. It is then wound and cut with a constant tension of 200N, and the cutting accuracy is controlled within ±1mm to obtain E8-T650 fabric.

[0030] The total weight of the E8-T650 fabric prepared in this example was measured to be 647 g / m². 2 .

[0031] Comparative Example 1 The difference between this comparative example and Example 1 is that: conventional uniaxial E8 glass fiber fabric was used, without a 0° flow guide layer, conventional drying was performed, the stitch-knitted structure is 1-0 / 1-2 / / , and there is no gradient setting. The resulting fabric is as follows. Figure 2 As shown.

[0032] Comparative Example 2 The difference between this comparative example and Example 1 is that it only uses ordinary biaxial laying, without 0° equidistant flow guide structure, and without equidistant flow channels.

[0033] Comparative Example 3 The difference between this comparative example and Example 1 is that it uses the original weave 1-0 / 1-2 / / , 75D polyester yarn, and the 0° yarn weight is 40g / m². 2 The dehumidification process is without negative pressure and uses a single-stage 90℃ heat setting method.

[0034] Test case Samples: Examples 1-3 and Comparative Examples 1-3 The above samples were taken and their material properties and laying effects were tested and measured. The specific test indicators and methods involved are as follows: Tensile properties: GB / T1447-2005 "Test Method for Tensile Properties of Fiber Reinforced Plastics"; Compression performance: GB / T1448-2005 "Test Method for Compression Properties of Fiber Reinforced Plastics"; Shear properties: GB / T1450.1-2005 "Test Method for Interlaminar Shear Strength of Fiber Reinforced Plastics"; Resin impregnation rate: Vacuum infusion method, record complete impregnation time; Layup efficiency: 100m-class blade circumferential layup (100m) 2 Working hours statistics; Overlap defect rate: Ultrasonic C-scan detection after manual layup; Dimensional stability: Width deviation and heat shrinkage rate testing; Grammage accuracy: Mass test per unit area.

[0035] (1) Results and analysis of material properties: The results of the material performance tests on the above samples are shown in Table 1 below: Table 1. Material property test results of different samples

[0036] The comparative analysis of the measurement results in Table 1 above shows that the E8-T650 fabrics of Examples 1-3 have significantly higher mechanical properties than the fabrics of Comparative Examples 1-3 in terms of tensile strength, 90° tensile modulus, and shear strength. This indicates that the E8-T650 fabric proposed in this invention is more suitable for and meets the high mechanical performance requirements of circumferential bearing capacity of 100-meter-class wind turbine blades.

[0037] (2) Results and analysis of resin impregnation and layup efficiency: The results of the above samples after resin impregnation and other tests are shown in Table 2 below: Table 2. Results of resin impregnation and layup efficiency measurements for different samples.

[0038] The comparative analysis of the measurement results in Table 2 above shows that, compared with the fabrics prepared using existing technology in Comparative Examples 1-3, the resin impregnation speed of the E8-T650 fabrics in Examples 1-3 is significantly improved. This indicates that the resin impregnation effect can be effectively improved by constructing a 0° equidistant flow channel structure proposed in this invention, thereby significantly shortening the injection cycle and reducing white spots and pore defects.

[0039] Meanwhile, the E8-T650 fabric layup in Examples 1-3 has short working time and very few overlap defects, which shows that the E8-T650 fabric proposed in this invention can be laid up in the whole width without breaks when laying up large blades, effectively solving the problems of stress concentration and weak strength in traditional technology.

[0040] (3) Results and analysis of dimensional stability and weight accuracy measurements: The results of the above samples after dimensional stability and other tests are shown in Table 3 below: Table 3. Results of dimensional stability and weight accuracy measurements for different samples.

[0041] The comparative analysis of the measurement results in Table 3 above shows that the E8-T650 fabrics of Examples 1-3 were prepared using the improved processes of negative pressure dehumidification activation and gradient heat setting proposed in this invention. Their width deviation is ≤ ±3 mm, heat shrinkage rate is ≤ 0.14%, and weight fluctuation is ≤ ±1.5%. That is, the dimensional stability and weight accuracy are significantly higher than the material properties of the fabrics prepared by existing technologies in Comparative Examples 1-3.

[0042] (4) Results and analysis of multi-layered stitching compatibility test: The results of the multi-layer stitch-knit compatibility test of the above samples are shown in Table 4 below: Table 4. Results of multi-layer stitching compatibility testing for different samples

[0043] The comparative analysis of the measurement results in Table 4 above shows that: Examples 1-3 are E8-T650 fabrics made by the present invention using 100D high-shrinkage polyester yarn and combined with the improved process of Tricot (1-0 / 2-3 / / ) stitch weaving structure, etc. The composite delamination rate and interlayer slippage of the fabrics in Examples 1-3 are significantly lower than those in Comparative Examples 1-3. This shows that the E8-T650 fabric and its preparation method proposed in the present invention can make the fabric non-slip, non-delamination, and firmly bound when combined with multilayer reinforcing materials, which significantly improves the blade layup efficiency and structural stability.

[0044] The E8-T650 fabric for multi-layer stitching and circumferential layup provided by this invention has mechanical properties that meet the requirements for use in 100-meter-class wind turbine blades. It also has the advantages of fast resin impregnation, high layup efficiency, extremely low overlap defect rate, dimensional stability, and compatibility with multi-layer stitching. It effectively overcomes the technical difficulties in the prior art, such as low efficiency of manual layup, large circumferential overlap deviation, stress concentration, slow impregnation, and easy delamination of multi-layer composites.

[0045] 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 multi-layer stitch-knitted and circumferentially laid E8-T650 fabric, characterized in that, It includes a 90° main reinforcing yarn, a 0° flow-guiding reinforcing yarn, and a binding stitch-woven yarn. The 90° main reinforcing yarn is made of E8 glass fiber yarn, and the 0° flow-guiding reinforcing yarn is made of E6 glass fiber yarn. The 90° main stress layer and the 0° equidistant flow-guiding layer have a biaxial asymmetric structure.

2. The E8-T650 fabric for multi-layer stitching and circumferential lay-up according to claim 1, characterized in that, The unit area mass of the 90° main reinforcing yarn is controlled at (598±3%) g / m. 2 .

3. The E8-T650 fabric for multi-layer stitching and circumferential lay-up according to claim 1, characterized in that, The unit area mass of the 0° flow-guiding reinforcing yarn is controlled at (42±2%) g / m. 2 .

4. The E8-T650 fabric for multi-layer stitching and circumferential lay-up according to claim 1, characterized in that, The binding and stitching yarn uses 100D polyester yarn, and the unit area mass of the binding and stitching yarn is controlled at (6±2%) g / m. 2 .

5. The E8-T650 fabric for multi-layer stitching and circumferential lay-up according to claim 1, characterized in that, The total weight of the E8-T650 fabric used for multi-layer stitching and circumferential lay-up is (646±3%) g / m². 2 .

6. A method for preparing a multi-layer stitch-knitted and circumferentially laid E8-T650 fabric as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1 Dehumidification and Activation Treatment: The 90° main reinforcing yarn and the 0° flow-guiding reinforcing yarn are heated and depressurized separately for dehumidification and activation treatment until the moisture content drops below 0.02% for later use. S2 graded tension warping: Segmented tension compensation is adopted to control the tension of the 90° main reinforcing yarn to be 220-240 cN / yarn and the tension of the 0° guiding reinforcing yarn to be 90-110 cN / yarn; S3 90° Main Reinforcing Yarn Parallel Laying: The tension-adaptive parallel weft laying method is used to lay the 90° main reinforcing yarn in parallel. S4 0° flow-guiding and reinforcing yarns are laid out at equal intervals: The 0° flow-guiding reinforcing yarns are laid at equal intervals to form flow channels; S5 stitch binding: Bind with Tricot (1-0 / 2-3 / / ) stitches; S6 gradient heat setting treatment: Heat setting was performed using a temperature gradient of 80-90℃, 90-100℃, and 70-90℃ in sequence. S7 Cold Air Shaping and Rewinding / Slitting: The E8-T650 fabric for multi-layer stitching and circumferential lay-up is obtained by cold air setting and constant tension winding and cutting.

7. The method for preparing E8-T650 fabric for multi-layer stitch-knitting and circumferential lay-up according to claim 6, characterized in that, In step S1, the ambient temperature is 70-80℃, the ambient pressure is -0.05MPa to -0.01MPa, and the dehumidification and activation treatment lasts for 30-50 minutes.

8. The method for preparing E8-T650 fabric for multi-layer stitch-knitting and circumferential lay-up according to claim 6, characterized in that, In step S3, the weft laying speed is controlled at 9-11 m / min, and the weft laying accuracy is maintained at ≤±2% for weight fluctuation.

9. The method for preparing E8-T650 fabric for multi-layer stitching and circumferential lay-up according to claim 6, characterized in that, In step S4, the 0° guiding reinforcement yarn is laid out at equal intervals of 3.5±0.2mm, and the flatness is controlled to ensure that the local protrusions are ≤0.8mm.

10. The method for preparing E8-T650 fabric for multi-layer stitch-knitting and circumferential lay-up according to claim 6, characterized in that, In step S5, the stitch density is 4-8 ends / inch, the stitch length is 2.5-3.0 mm, the tension of the binding stitch yarn is 20-30 cN, and the stitching speed is 7-9 m / min.

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