Pre-embedded strips, equipment and process for epoxy resin-based fiber-reinforced high modulus wind turbine blades

Abstract

The present invention discloses an embedded strip, equipment and process for epoxy resin-based fiber-reinforced high modulus wind turbine blades. The embedded strip comprises: a composite material body and a composite surface felt, wherein the composite surface felt is arranged on the upper and lower surfaces of the composite material body; the composite material body is a glass fiber-reinforced epoxy resin composite material; the glass fiber comprises untwisted roving glass fiber, bulked yarn glass fiber and glass fiber cloth, wherein the untwisted roving glass fiber and bulked yarn glass fiber are uniformly arranged in multiple layers along the length direction in the composite material body to form a multi-layer structure, and the glass fiber cloth is arranged in at least one layer along the length direction in the multi-layer structure. The embedded strip is a high modulus embedded strip reinforced with epoxy resin-based fibers. The embedded strip manufactured by this method has the advantages of high modulus, certain toughness and anti-aging performance, and can meet the current production requirements of blades for units below 7MW.

Description

Technical Field

[0001] The invention belongs to the field of wind power generation, and in particular relates to an epoxy-based fiber reinforced high-modulus and high-toughness pre-embedded strip, equipment and process for wind power blades. Background Art

[0002] A wind turbine is a power generation device composed of blades, transmission systems, generators, power storage devices, towers and electrical systems. The key to obtaining greater wind power generation is to have blades that can rotate easily, so wind turbine blade technology is the core technology of wind turbines.

[0003] Since the blades directly face the wind to obtain wind energy, the blades are required to have a reasonable structure. High-quality materials and advanced technology enable the blades to reliably bear the wind force. The blades' own weight, centrifugal force, etc. give the blades various bending and tensile forces. The structure must have high strength, fatigue resistance, high temperature resistance, reliable operation, and easy manufacturing. Manufacturing cost and use cost are all factors to be considered.

[0004] An important sign of the development of wind power technology is the increase in the capacity of a single unit. For every doubling of its capacity, the cost of power generation will drop by about 15%. Countries around the world that develop wind power generation are constantly increasing the capacity of single units. With the improvement of wind turbine blade design technology, wind power generation has developed from high power and long blades. The increase in blade size can improve the economy of wind power generation and reduce the cost of power generation. The blade length has grown from 4.5 meters in 1980 to 90 meters today, and the capacity has grown from 55KW to 10MW today. The materials have also developed from wood and metal to today's composite materials. Generally, smaller blades are less than 22 meters, and E or ECR glass fiber reinforced plastics are used, and unsaturated polyester resins are used for the resin base. Vinyl resin and epoxy resin can also be used, while larger blades over 42 meters generally use E or ECR glass fiber + epoxy resin base and carbon fiber + epoxy resin base reinforced plastics. Since the cost of carbon fiber is nearly ten times that of epoxy resin, it has the highest performance but poor cost performance. At present, glass fiber reinforced plastics + epoxy resin base are still basically used to produce blade materials, so as the length of the blade increases, the strength of the blade should also increase.

[0005] The blade of a wind turbine is a thin shell structure made of fiber-reinforced composite materials, consisting of a root shell and a main beam. The root of the blade is the key part of the connection between the blade and the wind turbine rotor hub, and is subjected to complex shear, extrusion, bending and torsion. Therefore, the blade root connection must have sufficient mechanical strength and bending stiffness. The connection between the blade bolt and the blade root is usually made by pre-embedding and connecting the blade root bolt sleeve. The pre-embedded strip improves the strength and stability of the blade by pre-embedding the blade root, ensuring the reliable connection between the blade bolt and the rotor hub and the safe operation of the blade.

[0006] Unsaturated polyester resin + glass fiber reinforcement has low manufacturing cost, but its strength cannot meet the strength requirements of large-sized blades. Carbon fiber has high strength and light weight, and is the direction of future blade design and development, but the price of carbon fiber is too high, and the production cost of blades is too high, so it cannot be commercialized in large quantities. Summary of the invention

[0007] In order to overcome the technical problem that the strength of unsaturated polyester resin products cannot meet the strength of large-sized blades, the purpose of the present invention is to provide an epoxy resin-based fiber-reinforced high-modulus embedded strip, equipment and process for wind turbine blades. The embedded strip for wind turbine blades is a high-modulus embedded strip reinforced with epoxy resin-based fibers. The embedded strip manufactured by this method has the advantages of high modulus, certain toughness and anti-aging performance, and can meet the current production requirements of blades for units below 7MW.

[0008] In order to achieve the above object, the present invention adopts the following technical means:

[0009] An epoxy resin-based fiber-reinforced high-modulus wind turbine blade embedded strip, comprising:

[0010] A composite material body and a composite surface felt, wherein the composite surface felt is arranged on the upper and lower surfaces of the composite material body; the composite material body is a glass fiber reinforced epoxy resin composite material;

[0011] The glass fibers include untwisted roving glass fibers, bulked roving glass fibers and glass fiber cloth. The untwisted roving glass fibers and bulked roving glass fibers are evenly arranged along the length direction in the composite material body, and the glass fiber cloth is provided with at least one layer along the length direction in the composite material body.

[0012] As a further improvement of the present invention, the composite material body comprises, by mass percentage:

[0013] Glass fiber: 70%-78%;

[0014] Epoxy resin: 11.5%-18%;

[0015] Curing agent: 8.5%-13%;

[0016] Accelerator: 0.5%-0.65%;

[0017] Other additives: 0.08%-0.12%;

[0018] As a further improvement of the present invention, the curing agent is methyltetrahydrophthalic anhydride or methylnadic anhydride;

[0019] The accelerator is DMP30 or imidazole;

[0020] The other auxiliary agents are one or more of ultraviolet absorbers, antioxidants and light stabilizers.

[0021] As a further improvement of the present invention, the glass fiber comprises, by mass percentage:

[0022] Roving glass fiber: 70-80%;

[0023] Bulked yarn glass fiber: 20%-25%;

[0024] Fiberglass cloth: 5-10%.

[0025] As a further improvement of the present invention, the glass fiber cloth is a fiber cloth formed by sewing and weaving multi-axial fibers; the composite surface felt is obtained by compounding glass fiber cloth and polyester surface felt.

[0026] A manufacturing device for pre-embedded strips for epoxy resin-based fiber-reinforced high-modulus wind turbine blades, comprising a yarn rack, a yarn guide rack, a first placement rack, a first yarn guide and felt guide plate, a dipping tank, a second yarn guide and felt guide plate, a second placement rack, a mold, a traction device and a cutting machine arranged in sequence;

[0027] The yarn rack is used to place the yarn balls of untwisted roving glass fiber and bulked glass fiber; the first placement rack is used to place glass fiber cloth; the dipping tank is filled with glue;

[0028] A second placement rack is respectively arranged above and below the second yarn guide and felt guide plate, and the second placement rack is used to place the composite surface felt;

[0029] During operation, the yarn head of the yarn ball passes through the yarn guide frame and the glass fiber cloth through the first yarn guide felt guide plate into the glue dipping tank, passes through the second yarn guide felt guide plate and enters the mold together with the upper and lower composite surface felts; after leaving the mold, it is pulled to the cutting machine by the pulling device.

[0030] As a further improvement of the present invention, each row of the yarn rack is provided with a yarn threading plate, and the yarn heads of the yarn balls pass through each yarn threading plate in order and are evenly arranged on the yarn guide rack according to the number of layers.

[0031] As a further improvement of the present invention, the end face shape of the second yarn and felt guide plate is consistent with the cross-sectional shape of the embedded part and is proportionally enlarged;

[0032] The two first placing racks are arranged between the yarn guide rack and the first yarn guide and felt guide plates.

[0033] As a further improvement of the present invention, the glue solution is composed of epoxy resin, curing agent, accelerator and other auxiliary agents.

[0034] The production process of the pre-embedded strip manufacturing equipment for epoxy resin-based fiber-reinforced high modulus wind turbine blades includes the following steps:

[0035] The glass fiber is measured by placing the yarn balls of the untwisted roving glass fiber and the bulked glass fiber on the yarn frame, and the yarn heads of the yarn balls evenly pass through the yarn guide frame according to the number of layers and enter the first yarn guide and felt guide plate;

[0036] The glass fiber cloth placed on the first placement rack is distributed in the glass fiber roving, glass fiber and glass fiber bulked yarn through the first yarn guide and felt guide plate to form a multi-layer structure;

[0037] The multi-layer structure enters the dipping tank for dipping; after dipping, it enters the second yarn guide and felt guide plate for preforming;

[0038] Two composite surface felts are arranged on the upper and lower surfaces of the composite structure impregnated with glue, and are put into the mold together for heating and curing to form strip embedded parts;

[0039] The strip-shaped embedded parts are pulled and extruded by a traction device and cut by a cutting machine to obtain individual embedded strips.

[0040] Compared with the prior art, the present invention has the following advantages:

[0041] The embedded strip body for wind turbine blades of the present invention is reinforced with epoxy resin-based fibers. During the production process, bulked yarn is added to the embedded part. The bulked yarn is a specially treated glass fiber. The yarn is fluffy and can carry more epoxy resin into the product. Sufficient epoxy resin can ensure reliable bonding between the glass fiber and the epoxy resin interface. The addition of multi-axial glass fiber cloth (felt) ensures that the multi-directional force strength of the product is increased, thereby improving the strength of the wind blade.

[0042] Furthermore, by adding anti-ultraviolet agents, antioxidants, light stabilizers and other additives to the epoxy resin glue, the anti-ultraviolet and anti-aging properties of the product can be improved and the life of the product can be extended.

[0043] Furthermore, the present invention adds bulked yarn and multi-axial glass fiber composite felt and high-performance epoxy resin, and adds antioxidants, anti-ultraviolet agents, light stabilizers and other additives to the resin base, which can improve the mechanical properties and anti-aging properties of the product.

[0044] Furthermore, since bulked yarn and glass fiber multi-axial cloth are added to the product, a preformed yarn guide and felt guide plate is added before the glass fiber, bulked yarn and glass fiber multi-axial cloth are put into the mold, thereby ensuring that the glass fiber, bulked yarn and glass fiber multi-axial felt enter the mold smoothly, forming a mesh structure in the product and improving the overall strength of the product.

[0045] The glass fiber in the equipment of the present invention is a combination of ordinary pultruded glass fiber and bulked glass fiber, which can meet the requirements of high modulus of wind turbine blades and the requirements of the proportion of each component of embedded strip products for wind turbine blades; bulked yarn glass fiber has the characteristics of large volume and strong adsorption capacity. By increasing the amount of bulked glass fiber, the amount of untwisted coarse yarn glass fiber can be reduced. Its strong adsorption capacity can bring more glue into the mold cavity, and improve the content ratio and volume ratio of resin to fiber in the embedded product. The content ratio of glass fiber and resin can be better controlled, and the toughness of the product can be improved after the resin content is increased. At the same time, the weight of the embedded parts can be reduced, which is beneficial to the quality control of the next process of the product. The use of added glass fiber cloth (felt) can improve the comprehensive strength of the embedded parts, especially the lateral strength.

[0046] Furthermore, through the uniform arrangement and multi-layer design of various glass fiber products, different glass fibers are evenly distributed according to the pre-designed positions through each yarn guide frame and pre-formed plate in front of the mold. Make good preparations for the diversion in front of the multi-layer design. Through the pre-formed plate in front of the mold, it enters the mold smoothly, orderly, neatly and evenly, and is heated and cured to ensure the high modulus and high toughness performance requirements of the comprehensive strength requirements of the embedded parts.

[0047] Furthermore, by adding composite surface felt, the anti-aging ability of the product can be further improved. By adding composite surface felt, the thickness of the resin layer on the surface of the product can be increased, and a thick protective film can be formed on the surface of the product. Polyester surface felt itself has good anti-aging function, and the cooperation of various additives further improves the excellent anti-aging ability of the product.

[0048] The preparation process of the present invention uses high-quality epoxy resin, curing agent, and glass fiber pultrusion. The glass fiber is placed on a yarn rack and arranged in order to pass through the yarn guide in turn to ensure uniform tension of the glass fiber. The embedded strip for wind turbine blades of the present invention has transverse tensile strength, impact strength, anti-aging performance, high toughness, high modulus, and more uniform distribution of each component, and more reasonable cost control. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the manufacturing equipment of the embedded strips for wind turbine blades of the present invention. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0051] like Figure 1 As shown, the present invention provides an epoxy resin-based fiber-reinforced high-modulus embedded strip manufacturing device for wind turbine blades, comprising a yarn rack 1, a yarn guide rack 2, a first placement rack 3, a first yarn guide felt plate 4, a dipping tank 5, a second yarn guide felt plate 6, a second placement rack 7, a mold 8, a traction device 9 and a cutting machine 10 arranged in sequence;

[0052] The yarn rack 1 is used to place the yarn balls of untwisted roving glass fiber and bulked glass fiber; the first placement rack 3 is used to place glass fiber cloth; the dipping tank 5 is filled with glue;

[0053] A second placement rack 7 is respectively arranged above and below the second yarn guide and felt guide plate 6, and the second placement rack 7 is used to place the composite surface felt; each row of the yarn frame 1 is provided with a yarn threading plate, and the yarn heads of the yarn balls pass through each yarn threading plate in an orderly manner and are evenly arranged on the yarn guide frame 2 according to the number of layers.

[0054] The end face shape of the second yarn guide and felt guide plate 6 is consistent with the cross-sectional shape of the embedded part and is proportionally enlarged; the two first placement racks 3 are arranged between the yarn guide rack 2 and the first yarn guide and felt guide plate 4. The glue is composed of epoxy resin, curing agent, accelerator and other additives.

[0055] During operation, the yarn head of the yarn ball passes through the yarn guide frame 2 and the glass fiber cloth through the first yarn guide felt guide plate 4 into the glue dipping tank 5, passes through the second yarn guide felt guide plate 6 and enters the mold 8 together with the upper and lower composite surface felts; after leaving the mold 8, it is pulled to the cutting machine 10 by the pulling device 9.

[0056] The two types of glass fibers on the yarn frame 1 are reasonably arranged according to the proportion of ingredients, so that the two types of glass fibers entering the yarn guide frame 2 are evenly distributed and meet the requirements of the mass proportion on a single cross section.

[0057] As a preferred embodiment, each row of the yarn frame 1 is provided with a yarn threading plate, and the yarn ends of the yarn balls pass through each yarn threading plate in order and are evenly arranged on the yarn guide frame 2 according to the number of layers.

[0058] As a preferred embodiment, one or more first placement racks 3 are provided, and the glass fiber cloth enters the first yarn guide plate 4 in one row or multiple rows.

[0059] As a preferred embodiment, the end face shape of the second yarn and felt guide plate 6 is consistent with the cross-sectional shape of the embedded part and is enlarged in equal proportion.

[0060] As a preferred embodiment, two first placement racks 3 are arranged between the yarn guide rack 2 and the first yarn and felt guide plate 4.

[0061] The present invention also provides a production process for manufacturing equipment for epoxy resin-based fiber-reinforced high-modulus embedded strips for wind turbine blades, comprising the following steps:

[0062] Glass fiber quantity: The yarn balls of untwisted roving glass fiber and bulked glass fiber are placed on the yarn rack 1, and the yarn heads of the yarn balls evenly pass through the yarn guide rack 2 according to the number of layers, and enter the first yarn guide and felt guide plate 4;

[0063] The glass fiber cloth placed on the first placement rack 3 is distributed in the glass fiber roving glass fiber and the glass fiber bulked yarn through the first yarn guide plate 4 to form a multi-layer structure;

[0064] The multi-layer structure enters the dipping tank 5 for dipping; after dipping, it enters the second yarn guide and felt guide plate 6 for preforming;

[0065] Two composite surface felts are arranged on the upper and lower surfaces of the composite structure impregnated with glue, and enter the mold 8 together for heating and curing to form a strip-shaped embedded part;

[0066] The strip-shaped embedded parts are pulled and extruded by the traction device 9 and cut by the cutting machine 10 to obtain individual embedded strips.

[0067] The specific process is as follows:

[0068] Before production, first budget the amount of glass fiber to be used, evenly distribute it in the ratio of 20%-30% and 80%-70%, divide the glass fiber into untwisted roving glass fiber and bulked glass fiber, and put it on the creel 1. The yarn on the creel 1 must be placed neatly and orderly, in a row horizontally and in a row vertically. There is a corresponding yarn feeding board on each row of yarn. The yarn ball must be placed below the center of the yarn feeding board and cannot deviate from the center point. Then take out the yarn head of the yarn ball and pass it through each yarn feeding board in order. They cannot cross, entangle, or jump boards with each other.

[0069] A yarn guide frame 2 is arranged in front of the yarn frame 1 to pass the yarn of each layer through the yarn guide frame 2 in order and evenly arrange the yarn on the yarn guide frame 2 according to the number of layers. A first yarn guide felt guide plate 4 is arranged in front of the yarn guide frame 2. A first placement rack 3 for glass fiber cloth is arranged between the yarn guide frame 2 and the first yarn guide felt guide plate 4. The glass fiber cloth passes through the first yarn guide felt guide plate 4 and is evenly distributed in two layers between the glass fiber untwisted roving, glass fiber and glass fiber bulked yarn. There is a dipping box (slot) 5 in front of the first yarn guide felt plate 4, and there is a preformed second yarn guide felt plate 6 in front of the dipping box (slot) 5. The shape of the second yarn guide felt plate 6 is the same as the cross-sectional shape of the embedded product, but the size is enlarged to ensure that the glass fiber is evenly distributed and clearly layered. The glass fiber and glass fiber cloth (felt) pass through the yarn frame 1, the yarn guide frame 2, the first yarn guide felt plate 4, the dipping box (slot) 5, and the second yarn guide felt plate 6 in sequence, and then enter the mold 8. Through the traction device 9, all the glass fibers are pulled out of the mold 8, and the mold 8 is heated to a preset temperature. There are two upper and lower composite surface felt second placement racks 7 at the entrance of the mold 8. The upper and lower composite surface felts and the glass fibers impregnated with glue are put into the mold 8 and pulled out of the mold 8. The traction device 9 should be equipped with a clamp device with the same cross-sectional shape as the embedded product to ensure that there is no slipping or stopping during the production process, and the products produced are not deformed or twisted. There is a cutting machine 10 in front of the traction device 9 to cut according to the required size.

[0070] Furthermore, the mold 8 is provided with a plurality of heating sections along the advancing direction of the yarn end.

[0071] The mold 8 is heated in sections, wherein the temperatures of the A / B / C sections are: zone A 100°C to 150°C; zone B 150°C to 175°C; zone C 160°C to 180°C.

[0072] Heat the mold 8 to a preset temperature, prepare the glue in advance according to the designed ratio, pour the prepared glue into the dipping box (trough) 5, start production, adjust the pultrusion speed to within the range required by the process, pass the product through the traction device 9 smoothly, saw off the waste head that is not well soaked in front, observe whether there are cracks on the end face and outer surface of the product, and measure whether the size of the product meets the requirements.

[0073] The glue is a premix composed of epoxy resin, curing agent, accelerator and other additives.

[0074] Preferably, there are two traction devices 9 , which are arranged at an interval, and the yarn ends enter the cutting machine 10 after passing through the two traction devices 9 in sequence.

[0075] Furthermore, the pulling speed is 8-15 cm / min.

[0076] The epoxy resin-based fiber-reinforced high-modulus embedded strip for wind turbine blades prepared by the present invention comprises, according to the structure:

[0077] A composite material body and a composite surface felt, wherein the composite surface felt is arranged on the upper and lower surfaces of the composite material body; the composite material body is a glass fiber reinforced epoxy resin composite material;

[0078] The glass fibers include untwisted roving glass fibers, bulked roving glass fibers and glass fiber cloth. The untwisted roving glass fibers and bulked roving glass fibers are evenly arranged along the length direction in the composite material body, and the glass fiber cloth is provided with at least one layer along the length direction in the composite material body.

[0079] According to the chemical composition, the embedded part is composed of the following chemical components: glass fiber, epoxy resin, curing agent, accelerator, and other additives. The chemical composition ratio (weight ratio) of the embedded part is:

[0080] Glass fiber: 70%-78%;

[0081] Epoxy resin: 11.5%-18%;

[0082] Curing agent: 8.5%-13%;

[0083] Accelerator: 0.5%-0.65%;

[0084] Other additives: 0.08%-0.12%.

[0085] The glass fiber refers to: E or ECR glass fiber, and the glass fiber includes: roving glass fiber, bulked glass fiber and glass fiber cloth or cloth.

[0086] Among them, the untwisted roving glass fiber is a special glass fiber for pultrusion, and the expanded glass fiber is a fiber processed by a special process, which has special functions such as large volume, strong adsorption capacity, and improved uniform distribution of materials in dead corners of products. It can effectively control the ratio and uniformity of glass fiber and resin in the product and ensure the stability of the product. The usage ratio of expanded glass fiber and untwisted roving glass fiber is:

[0087] Expanded glass fiber accounts for 20%-30% of the total fiber volume;

[0088] Untwisted roving glass fiber accounts for 80%-70% of the total fiber volume;

[0089] Glass fiber cloth accounts for 5-10% of the total fiber volume.

[0090] Among them, glass fiber cloth (felt) is a fiber cloth (felt) made of multi-axial fibers sewn together. Specifically, there are fibers in multiple directions, including transverse fibers, longitudinal fibers, and fibers with an angle of 45 degrees. The comprehensive strength of the product can be greatly improved, because the pultrusion process is mostly longitudinal fibers, so the longitudinal tensile strength is very high, but the transverse strength is relatively low. Adding multi-axial fiber cloth (felt) can greatly improve this problem, because multi-axial fiber cloth (felt) has fibers in multiple directions, which can effectively improve the amount of transverse fibers in the product, and form a mesh form with the longitudinal fibers, greatly improving the transverse strength and comprehensive strength of the product.

[0091] Composite surface felt is a kind of felt composed of fiber felt and polyester surface felt. Its main function is to increase the thickness of the resin layer on the surface of the product, increase the brightness of the product surface, and improve the anti-aging ability of the product.

[0092] The epoxy resin mentioned above refers to: high-performance, high-toughening epoxy resin, which can greatly improve the toughness of the product. Products made of ordinary epoxy resin have high strength and strong rigidity, but are brittle and have poor toughness. This high-performance, high-toughening epoxy resin can not only ensure the high strength and high rigidity of the product, but also ensure the high toughness of the product, and improve the product's impact resistance and temperature change resistance and cracking resistance.

[0093] The curing agent is methyltetrahydrophthalic anhydride or methylnadic anhydride.

[0094] The accelerator is: DMP30 or imidazole.

[0095] The other additives include: UV absorbers, antioxidants, light stabilizers and the like.

[0096] The embedded parts made of the above ingredients can strictly control the proportion of each component in the embedded parts, especially the proportion of resin and glass fiber, and the uniformity of distribution of each component, thereby improving the toughness of the embedded parts and the stability of product quality, impact resistance and aging resistance.

[0097] The present invention selects different types of high-performance chemical components, evenly distributes the components in the embedded parts, accurately controls the proportion of the components, and strictly controls the process index parameters, so that the components can be produced into high-modulus and high-toughness glass fiber reinforced embedded parts through a molding die.

[0098] Several specific groups of commonly used embodiments are given below to illustrate the present invention in detail.

[0099] Example 1

[0100] The chemical composition ratio (weight ratio) of the embedded part is:

[0101] Glass Fiber: 78%

[0102] Epoxy resin: 12.92%

[0103] Curing agent: 8.5%; methyltetrahydrophthalic anhydride;

[0104] Accelerator: 0.5%, imidazole;

[0105] Other additives: 0.08%, such as UV absorbers, antioxidants, light stabilizers.

[0106] The glass fiber is E glass fiber, and the glass fiber includes: untwisted roving glass fiber, bulked glass fiber and glass fiber cloth or cloth. The glass fiber is used in the following proportions:

[0107] Expanded glass fiber accounts for 20% of the total fiber volume;

[0108] The roving glass fiber accounts for 70% of the total fiber volume.

[0109] Glass fiber cloth accounts for 10% of the total fiber volume.

[0110] Example 2

[0111] The chemical composition ratio (weight ratio) of the embedded part is:

[0112] Glass fiber: 74.3%

[0113] Epoxy resin: 15%

[0114] Curing agent: 10%, methyl nadic anhydride;

[0115] Accelerator: 0.6%, DMP30;

[0116] Other additives: 0.1%, such as UV absorbers, antioxidants.

[0117] The glass fiber is ECR glass fiber, and the glass fiber includes: untwisted roving glass fiber, bulked glass fiber and glass fiber cloth or cloth. The usage ratio is:

[0118] Expanded glass fiber accounts for 20%-30% of the total fiber volume;

[0119] The untwisted roving glass fiber accounts for 80%-70% of the total fiber volume.

[0120] Glass fiber cloth accounts for 5-10% of the total fiber volume.

[0121] Example 3

[0122] The chemical composition ratio (weight ratio) of the embedded part is:

[0123] Glass Fiber: 70%

[0124] Epoxy resin: 18%

[0125] Curing agent: 11.23%, methyltetrahydrophthalic anhydride;

[0126] Accelerator: 0.65%, DMP30;

[0127] Other additives: 0.12%, such as UV absorbers.

[0128] The glass fiber is E ECR glass fiber, and the glass fiber includes: untwisted roving glass fiber, bulked glass fiber and glass fiber cloth or cloth. The usage ratio is:

[0129] Expanded glass fiber accounts for 20%-30% of the total fiber volume;

[0130] The untwisted roving glass fiber accounts for 80%-70% of the total fiber volume.

[0131] Glass fiber cloth accounts for 5-10% of the total fiber volume.

[0132] The above are several common formulations of the present invention. Other formulations may also be used to improve material performance.

[0133] The epoxy resin-based fiber-reinforced high modulus pre-embedded strip for wind turbine blades produced by this formula design and process design has excellent properties such as high modulus, high toughness, anti-aging, and impact resistance. Table 1 is a mechanical property test of the epoxy resin-based fiber-reinforced high modulus pre-embedded strip for wind turbine blades prepared by the present invention, specifically using the chemical ratio of Example 2.

[0134] Table 1

[0135] project Unsaturated system Epoxy system Tensile Strength 406MPa 856MPa Compression strength 169MPa 682MPa Bending Strength 533MPa 824MPa

[0136] It can be seen from Table 1 above that the epoxy resin-based fiber-reinforced high modulus embedded strip for wind turbine blades of the present application has excellent mechanical properties, has the advantage of high modulus, and can meet the current production requirements of blades for units below 7MW.

[0137] In summary, the present invention is characterized by:

[0138] 1. By selecting high-quality raw materials, especially resin matrix, glass fiber, etc., the high modulus, high toughness, anti-aging and impact resistance of the product can be improved. The resin is selected from high-toughness resin, which has high modulus and high toughness, so that the epoxy resin-based fiber-reinforced high modulus wind turbine blade embedded strip produced has high modulus and high toughness, which meets the technical requirements of the product. The glass fiber is selected from ordinary pultruded glass fiber and expanded glass fiber, which can not only meet the requirements of high modulus of wind turbine blades, but also meet the requirements of the proportion of each component of epoxy resin-based fiber-reinforced high modulus wind turbine blade embedded strip products; expanded yarn glass fiber has the characteristics of large volume and strong adsorption capacity. By increasing the amount of expanded glass fiber, the amount of untwisted roving glass fiber can be reduced. With its strong adsorption capacity, more glue can be brought into the mold cavity, and the content ratio and volume ratio of resin to fiber in the embedded product can be increased. It can better control the content ratio of glass fiber and resin, and the toughness of the product can be improved after the resin content is increased. At the same time, it can reduce the weight of the embedded parts, which is beneficial to the quality control of the next process of the product. The use of added glass fiber cloth (felt) can improve the comprehensive strength of embedded parts, especially the lateral strength.

[0139] 2. Through the uniform arrangement and multi-layer design of various glass fiber products, different glass fibers are evenly distributed according to the pre-designed positions through each yarn guide frame and preformed plate in front of the mold. Make good preparations for the diversion in front of the multi-layer design.

[0140] Through the preformed plate in front of the mold, they enter the mold smoothly, orderly, neatly and evenly, and are heated and cured to ensure the high modulus and high toughness performance requirements of the embedded parts' comprehensive strength requirements.

[0141] 3. By adding UV absorbers, light stabilizers, antioxidants and other additives, the anti-aging performance of epoxy resin-based fiber-reinforced high-modulus embedded strips for wind turbine blades can be improved and their service life can be extended. By adding composite surface felt, the anti-aging ability of the product can be further improved. Adding composite surface felt can increase the thickness of the resin layer on the surface of the product and form a thick protective film on the surface of the product. Polyester surface felt itself has a good anti-aging function, and the cooperation of various additives further improves the excellent anti-aging ability of the product.

[0142] In summary, the present invention preferably selects advanced raw materials, applies advanced multi-layer design concepts and the addition of relevant additives, and ensures the quality stability, high strength requirements, impact resistance and anti-aging properties of the invented product from each link from the proportion of each component, the degree of distribution uniformity, the control of resin content, formula design and strict process control to the final molding, so as to ensure the economic benefit and cost control of the invented product.

[0143] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0145] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. An epoxy resin-based fiber-reinforced high modulus wind turbine blade embedded strip, characterized in that: include: A composite material body and a composite surface felt, wherein the composite surface felt is arranged on the upper and lower surfaces of the composite material body; the composite material body is a glass fiber reinforced epoxy resin composite material; The glass fibers include untwisted roving glass fibers, bulked roving glass fibers and glass fiber cloth, wherein the untwisted roving glass fibers and bulked roving glass fibers are evenly arranged in the length direction of the composite material, and the glass fiber cloth is provided in at least one layer in the length direction of the composite material; The glass fiber comprises, by mass percentage: Untwisted roving glass fiber: 70-80%; Bulked yarn glass fiber: 20%-25%; Glass fiber cloth: 5-10%; And the total percentage of each component of glass fiber is 100%; The glass fiber cloth is a fiber cloth formed by sewing and weaving multi-axial fibers; the composite surface felt is obtained by compounding the glass fiber cloth and the polyester surface felt.

2. The epoxy resin-based fiber-reinforced high modulus wind turbine blade embedded strip according to claim 1, characterized in that: The composite material comprises, by mass percentage: Glass fiber: 70%-78%; Epoxy resin: 11.5%-18%; Curing agent: 8.5%-13%; Accelerator: 0.5%-0.65%; Other additives: 0.08%-0.12%.

3. The epoxy resin-based fiber-reinforced high modulus wind turbine blade embedded strip according to claim 2, characterized in that: The curing agent is methyltetrahydrophthalic anhydride or methylnadic anhydride; The accelerator is DMP30 or imidazole; The other auxiliary agents are one or more of ultraviolet absorbers, antioxidants and light stabilizers.

4. A production process for the epoxy resin-based fiber-reinforced high modulus embedded strip for wind turbine blades according to claim 1, characterized in that: A manufacturing device for pre-embedded strips for epoxy resin-based fiber-reinforced high-modulus wind turbine blades, the manufacturing device comprising a yarn rack (1), a yarn guide rack (2), a first placement rack (3), a first yarn guide felt plate (4), a glue dipping tank (5), a second yarn guide felt plate (6), a second placement rack (7), a mold (8), a traction device (9) and a cutting machine (10) arranged in sequence; The yarn rack (1) is used to place yarn balls of untwisted roving glass fibers and bulked glass fibers; the first placement rack (3) is used to place glass fiber cloth; the glue dipping tank (5) is filled with glue liquid; A second placement rack (7) is respectively arranged above and below the second yarn guide and felt guide plate (6), and the second placement rack (7) is used to place the composite surface felt; During operation, the yarn head of the yarn ball passes through the yarn guide frame (2) and the glass fiber cloth through the first yarn guide felt guide plate (4) and enters the glue dipping tank (5), passes through the second yarn guide felt guide plate (6), and enters the mold (8) together with the upper and lower composite surface felts; after exiting the mold (8), it is pulled by the pulling device (9) to the cutting machine (10); The production process comprises the following steps: The glass fiber mass is to place yarn balls of untwisted roving glass fiber and bulked glass fiber on a yarn rack (1), and the yarn ends of the yarn balls are uniformly passed through a yarn guide rack (2) according to the number of layers, and enter a first yarn guide felt plate (4); The glass fiber cloth placed on the first placement rack (3) is distributed in the glass fiber untwisted roving glass fiber and the glass fiber bulked yarn through the first yarn guide and felt guide plate (4) to form a multi-layer structure; The multi-layer structure enters the glue dipping tank (5) for dipping; after dipping, it enters the second yarn guide and felt guide plate (6) for preforming; Two composite surface felts are arranged on the upper and lower surfaces of the composite structure impregnated with glue, and are put into a mold (8) together for heating and curing to form a strip-shaped embedded part; The strip-shaped embedded part is pulled and extruded by the traction device (9) and then cut by a cutting machine (10) to obtain a single embedded strip.

5. The production process according to claim 4, characterized in that: Each row of the yarn frame (1) is provided with a yarn threading plate, and the yarn heads of the yarn balls pass through each yarn threading plate in an orderly manner and are evenly arranged on the yarn guide frame (2) according to the number of layers.

6. The production process according to claim 4, characterized in that: The end face shape of the second yarn and felt guide plate (6) is consistent with the cross-sectional shape of the embedded part and is proportionally enlarged; The two first placement racks (3) are arranged between the yarn guide rack (2) and the first yarn guide and felt guide plate (4).

7. The production process according to claim 4, characterized in that: The glue solution is composed of epoxy resin, curing agent, accelerator and other auxiliary agents.

Images