An epoxy vinyl glass steel wedge strip, a preparation method and a preparation system thereof

Abstract

This invention relates to the field of fiberglass technology, and in particular to an epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system; the preparation steps include: S1, mixing 79.4-84.7 parts by weight of bisphenol A epoxy vinyl ester resin, 1.7-2.5 parts of release agent, 0.8-1.6 parts of accelerator, 2.4-4.1 parts of low-shrinkage agent, 8.2-11.8 parts of filler, and 1.7-2.4 parts of curing agent, stirring evenly, and then degassing to obtain a resin solution; S2, direct glass fiber yarn and bulked glass fiber yarn are drawn into a glue tank containing resin solution through a yarn separating plate for impregnation to obtain impregnated yarn; S3, the impregnated yarn is cured and shaped, and cut into wedge strips of a specific length to obtain epoxy vinyl ester fiberglass wedge strips; the design of the epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system solves the technical problems of high density, low production efficiency, and high cost of existing epoxy vinyl ester fiberglass wedge strips.

Description

Technical Field

[0001] This invention relates to the field of fiberglass technology, and in particular to an epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system. Background Technology

[0002] Fiberglass reinforced plastic (FRP or GFRP), or fiber-reinforced plastic, refers to reinforced plastics with resin as the matrix material and glass fiber and / or its products as reinforcement. While single glass fibers possess high strength in the radial direction, they are loosely connected and cannot withstand bending, shear, and compressive stresses. They are also difficult to shape into fixed geometries, making them a soft material. The resin matrix, on the other hand, has lower strength and modulus but can withstand greater strain and exhibits viscoelasticity and elastoplasticity, making it a tough material. By bonding resin and fibers together using physical or chemical methods, various products with fixed shapes can be formed, capable of withstanding tensile stress as well as bending, compressive, and shear stresses. This constitutes glass fiber reinforced plastic matrix composites.

[0003] Fiberglass wedges, made of fiberglass, are commonly used in wind power equipment to secure the blades at the blade roots, acting as fixing bolt sleeves. However, with the increasing size of blades and their corresponding weight, the current use of epoxy-based fiberglass wedges presents several drawbacks: First, the high density of epoxy-based fiberglass wedges further increases the overall weight of the blades, failing to meet the requirements for lightweight and low-cost blades. Second, the increasing size of blades demands higher fatigue performance, and the currently used epoxy-based wedges are showing some limitations in this area. Third, the production of epoxy-based wedges suffers from high energy consumption and low production efficiency. Therefore, finding lower-density, more cost-effective raw materials and exploring high-efficiency, low-cost fiberglass wedges has become an important research direction for the fiberglass industry.

[0004] Therefore, in view of the above problems, the present invention urgently needs to provide an epoxy vinyl ester fiberglass wedge strip, its preparation method and preparation system. Summary of the Invention

[0005] The purpose of this invention is to provide an epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system. The design of the epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system aims to solve the technical problems of existing epoxy fiberglass wedge strips, such as high density, low production efficiency, and high cost.

[0006] The present invention provides a method for preparing an epoxy vinyl ester fiberglass wedge strip, comprising the following preparation steps:

[0007] S1 By weight, 79.4-84.7 parts of bisphenol A epoxy vinyl ester resin, 1.7-2.5 parts of release agent, 0.8-1.6 parts of accelerator, 2.4-4.1 parts of low shrinkage agent, 8.2-11.8 parts of filler and 1.7-2.4 parts of curing agent are mixed in sequence, stirred evenly and degassed to obtain a resin solution;

[0008] S2 glass fiber direct yarn and glass fiber bulked yarn are drawn into a glue tank containing resin solution through a yarn separating plate to impregnate the yarn.

[0009] S3 cures the impregnated yarn into shape and cuts it into wedge strips of a specific length to obtain epoxy vinyl ester fiberglass wedge strips.

[0010] Preferably, in step S1, the curing agent includes a low-temperature curing agent and a high-temperature curing agent, wherein the low-temperature curing agent is methyl isobutyl ketone peroxide and the high-temperature curing agent is tert-butyl peroxide.

[0011] The accelerator is an epoxy accelerator;

[0012] The low-shrinkage agent is polyethylene wax powder.

[0013] Preferably, in step S1, the weight ratio of methyl isobutyl ketone peroxide to tert-butyl peroxide is 2:1.

[0014] Preferably, in step S1, the stirring time is ≥5 min.

[0015] Preferably, in step S2, both the direct glass fiber yarn and the bulked glass fiber yarn have a specification of 4800 tex.

[0016] Preferably, in step S2, the traction speed is 0.15-0.3 m / min.

[0017] Preferably, in step S3, the impregnated yarn undergoes a two-stage curing process, firstly pre-curing and then secondary curing.

[0018] Preferably, during secondary curing, the temperature of the front zone of the curing mold is 120-130℃, and the temperature of the rear zone is 150-160℃.

[0019] The present invention also provides an epoxy vinyl ester fiberglass wedge strip obtained based on the preparation method of the epoxy vinyl ester fiberglass wedge strip as described in any one of the above-mentioned methods.

[0020] The present invention also provides a preparation system for producing epoxy vinyl ester fiberglass wedge strips as described above, including a glue tank, a yarn separating plate on one side of the glue tank, and a preforming mechanism, a cold mold, a curing mold, a copper wire traction mechanism, and a cutting mechanism sequentially arranged on the other side of the glue tank.

[0021] The epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system provided by this invention have the following advantages compared with the prior art:

[0022] 1. This invention provides an epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system. Through the formulation of the epoxy vinyl ester fiberglass wedge strip, bisphenol A type epoxy vinyl ester resin undergoes a copolymerization reaction under the action of a curing agent. During the curing process, the bisphenol A type epoxy vinyl ester resin exhibits a certain volume shrinkage. According to the volume shrinkage rate of the cured resin = (1 – ρbefore / ρafter) × 100%, the lower the density of the cured resin, the lower the volume shrinkage rate, and the larger the volume of the cured resin. This allows for better bonding between the direct fiberglass yarn and the expanded fiberglass yarn and the resin, resulting in a smaller fiber volume content per unit area. Without affecting the mechanical strength of the product, the density of the product is reduced, improving the fatigue resistance of the cured fiberglass. Simultaneously, production efficiency is improved, and energy consumption during production is reduced. This results in a lighter and more cost-effective fiberglass wedge strip with higher production efficiency and lower production costs.

[0023] 2. The epoxy vinyl resin of the present invention is a bisphenol A type epoxy vinyl ester. Bisphenol A type epoxy vinyl ester contains crosslinking points of unsaturated double bonds only at both ends of the molecular chain. Therefore, under stress, the entire molecular chain can be elongated, thus absorbing mechanical and thermal shocks. It exhibits good impact toughness, crack resistance and crack initiation performance in macroscopic properties.

[0024] 3. The glass fiber yarn of the present invention uses a combination of bulked yarn and direct yarn. In order to ensure the strength of the product, the traditional epoxy fiberglass wedge strip uses a single direct yarn as the reinforcement. While satisfying the strength of the fiberglass wedge strip in the X direction, the bulked yarn also strengthens the strength of the product in the Y direction to a certain extent because there is fiber overlap in the Y direction.

[0025] 4. The curing agent of this invention generates free radicals, thereby initiating a free radical chain polymerization reaction of resin containing unsaturated double bonds to achieve cross-linking and curing. It uses a compound of tert-butyl peroxide and methyl isobutyl ketone peroxide. Methyl isobutyl ketone peroxide decomposes rapidly at low temperatures, generating free radicals, initiating a polymerization reaction, releasing heat, and raising the system temperature. When the temperature reaches the critical decomposition temperature of tert-butyl peroxide, tert-butyl peroxide decomposes rapidly, generating a large number of free radicals, initiating a violent polymerization reaction, thereby achieving the purpose of rapid curing at a lower temperature. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 shows the preparation system of the epoxy vinyl ester fiberglass wedge strip described in this invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Glue tank; 2. Yarn separating plate; 3. Pre-forming mechanism; 4. Cold mold; 5. Curing mold; 6. Copper wire traction mechanism; 7. Cutting mechanism. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides a method for preparing epoxy vinyl ester fiberglass wedge strips, comprising the following preparation steps: S1, by weight, 79.4-84.7 parts of bisphenol A epoxy vinyl ester resin, 1.7-2.5 parts of release agent, 0.8-1.6 parts of accelerator, 2.4-4.1 parts of low-shrinkage agent, 8.2-11.8 parts of filler, and 1.7-2.4 parts of curing agent are mixed sequentially, stirred evenly, and degassed to obtain a resin solution; S2, glass fiber direct yarn and glass fiber bulked yarn are drawn into a glue tank containing resin solution through a yarn separating plate for impregnation to obtain impregnated yarn; S3, the impregnated yarn is cured and shaped, and cut into wedge strips of a specific length to obtain epoxy vinyl ester fiberglass wedge strips.

[0032] Specifically, in step S1, the curing agent includes a low-temperature curing agent and a high-temperature curing agent. The low-temperature curing agent is methyl isobutyl ketone peroxide, and the high-temperature curing agent is tert-butyl peroxide. The accelerator is an epoxy accelerator, and the low-shrinkage agent is polyethylene wax powder.

[0033] Specifically, in step S1, the weight ratio of methyl isobutyl ketone peroxide to tert-butyl peroxide is 2:1.

[0034] Specifically, in step S1, the stirring time is ≥5 min.

[0035] Specifically, in step S2, both the direct glass fiber yarn and the bulked glass fiber yarn have a specification of 4800 tex.

[0036] Specifically, in step S2, the traction speed is 0.15-0.3 m / min.

[0037] Specifically, in step S3, the impregnated yarn undergoes a two-stage curing process, firstly pre-curing and then a second curing.

[0038] Specifically, during the secondary curing process, the temperature of the front zone of the curing mold is 120-130℃, and the temperature of the rear zone is 150-160℃.

[0039] The present invention also provides an epoxy vinyl ester fiberglass wedge strip obtained based on the preparation method of the epoxy vinyl ester fiberglass wedge strip as described in any one of the above-mentioned methods.

[0040] like Figure 1 As shown, the present invention also provides a preparation system for producing epoxy vinyl ester fiberglass wedge strips as described above, including a glue tank 1, a yarn separating plate 2 on one side of the glue tank 1, and a preforming mechanism 3, a cold mold 4, a curing mold 5, a copper wire traction mechanism 6, and a cutting mechanism 7 arranged sequentially on the other side of the glue tank 1.

[0041] This invention provides an epoxy vinyl ester fiberglass wedge strip, its preparation method, and preparation system. Through the formulation of the epoxy vinyl ester fiberglass wedge strip, bisphenol A type epoxy vinyl ester resin undergoes a copolymerization reaction under the action of a curing agent. During the curing process, the bisphenol A type epoxy vinyl ester resin exhibits a certain volume shrinkage. According to the volume shrinkage rate of the cured resin = (1 – ρbefore / ρafter) × 100%, the lower the density of the cured resin, the lower the volume shrinkage rate, and the larger the volume of the cured resin. This allows for better bonding between the direct fiberglass yarn and the expanded fiberglass yarn and the resin, resulting in a smaller fiber volume content per unit area. Without affecting the mechanical strength of the product, the density of the product is reduced, improving the fatigue resistance of the cured fiberglass. Simultaneously, production efficiency is improved, and energy consumption during production is reduced. This results in a lighter and more cost-effective fiberglass wedge strip with higher production efficiency and lower production costs.

[0042] The epoxy vinyl resin of the present invention is a bisphenol A type epoxy vinyl ester. Bisphenol A type epoxy vinyl ester contains crosslinking points of unsaturated double bonds only at both ends of the molecular chain. Therefore, under stress, the entire molecular chain can be elongated, thus absorbing mechanical and thermal shocks. In terms of macroscopic properties, it has good impact toughness, crack resistance and crack initiation performance.

[0043] The fiberglass yarn of this invention uses a combination of bulked yarn and direct yarn. In order to ensure the strength of the product, the traditional epoxy fiberglass wedge strip uses a single direct yarn as the reinforcement. While satisfying the strength of the fiberglass wedge strip in the X direction, the bulked yarn also strengthens the strength of the product in the Y direction to a certain extent because there is fiber overlap in the Y direction.

[0044] The curing agent of this invention generates free radicals, thereby initiating a free radical chain polymerization reaction of resins containing unsaturated double bonds to achieve cross-linking and curing. It uses a compound of tert-butyl peroxide and methyl isobutyl ketone peroxide. Methyl isobutyl ketone peroxide decomposes rapidly at low temperatures, generating free radicals, initiating a polymerization reaction, releasing heat, and raising the system temperature. When the temperature reaches the critical decomposition temperature of tert-butyl peroxide, tert-butyl peroxide decomposes rapidly, generating a large number of free radicals, initiating a violent polymerization reaction, thereby achieving the purpose of rapid curing at a lower temperature.

[0045] Example 1

[0046] Preparation of Sample 1:

[0047] like Figure 1 As shown, this embodiment uses an epoxy vinyl ester fiberglass wedge strip preparation system to prepare epoxy vinyl ester fiberglass wedge strips. The production process is as follows:

[0048] (1) Prepare the equipment and thread the yarn. Fix the glass fiber direct yarn and glass fiber expanded yarn on the traction copper wire. Thread the yarn and preheat the curing mold 5. The temperature of the front zone is 120-130℃ and the temperature of the rear zone is 150-160℃. Preheat for 1.5-2 hours.

[0049] (2) Preparation of resin solution: 79.4 parts of bisphenol A epoxy vinyl ester resin, 2.4 parts of release agent, 1.6 parts of epoxy accelerator, 2.4 parts of polyethylene wax powder, 11.8 parts of filler, 1.6 parts of methyl isobutyl ketone peroxide, and 0.8 parts of tert-butyl peroxide are mixed in sequence, stirred with a disperser, allowed to stand to remove bubbles, and then transferred to glue tank 1.

[0050] (3) Profile production: Start the equipment and let the copper wire traction mechanism 6 pull the glass fiber yarn through the resin solution for impregnation. The traction speed is controlled at 0.15-0.3m / min. After impregnation, the yarn is pulled into the preforming mechanism 3 and then into the cold mold 4 for curing. The cured preformed product is pulled out of the cold mold 4 and then pulled into the curing mold 5. The preformed product is then cured again through the curing mold 5.

[0051] (4) Profile cutting: The product obtained after curing in step (3) is cut into wedge strips of a specific length by the cutting mechanism 7 to make epoxy vinyl ester fiberglass wedge strips.

[0052] The performance of sample 1 is shown in Table 1. The fiber volume content is 50%. According to standard GB / T 1463-2005, the product density is 1.8979 g / cm³. According to standard ISO 527-5, the product's tensile strength in the X direction is 501.96 MPa, tensile modulus in the X direction is 38.00 GPa, and tensile strength in the Y direction is 34.21 MPa.

[0053] Example 2

[0054] Preparation of Sample 2:

[0055] Sample 2 was prepared in the same way as Sample 1. The only difference was that the content of each component in the resin solution in step (2) of Sample 1 was different. The resin solution of Sample 2 contained: 81.3 parts of bisphenol A epoxy vinyl ester resin, 2.4 parts of release agent, 1.6 parts of epoxy accelerator, 4.1 parts of polyethylene wax powder, 8.2 parts of filler, 1.6 parts of methyl isobutyl ketone peroxide, and 0.8 parts of tert-butyl peroxide.

[0056] The performance of test sample 2 is shown in Table 1. Compared with sample 1, sample 1 has better product density, X-direction tensile strength, X-direction tensile modulus and Y-direction tensile strength.

[0057] Example 3

[0058] Preparation of Sample 3:

[0059] Sample 3 was prepared in the same way as Sample 1. The only difference was that the content of each component in the resin solution in step (2) of Sample 1 was different. The resin solution of Sample 3 contained: 82.6 parts of bisphenol A epoxy vinyl ester resin, 2.5 parts of release agent, 0.8 parts of epoxy accelerator, 4.1 parts of polyethylene wax powder, 8.3 parts of filler, 1.13 parts of methyl isobutyl ketone peroxide, and 0.57 parts of tert-butyl peroxide.

[0060] The performance of sample 3 is shown in Table 1. Compared with sample 1, sample 1 has better X-direction tensile strength, X-direction tensile modulus and Y-direction tensile strength. The product density of sample 1 is slightly greater than that of sample 3.

[0061] Example 4

[0062] Preparation of Sample 4:

[0063] Sample 4 was prepared in the same way as Sample 1. The only difference was that the content of each component in the resin solution in step (2) of Sample 1 was different. The resin solution of Sample 4 contained: 84.7 parts of bisphenol A epoxy vinyl ester resin, 1.7 parts of release agent, 0.8 parts of epoxy accelerator, 2.5 parts of polyethylene wax powder, 8.6 parts of filler, 1.13 parts of methyl isobutyl ketone peroxide, and 0.57 parts of tert-butyl peroxide.

[0064] The performance of sample 4 is shown in Table 1. Compared with sample 1, sample 4 has better X-direction tensile strength, X-direction tensile modulus and Y-direction tensile strength than sample 4. The product density of sample 1 is greater than that of sample 4.

[0065] Comparative Example 1

[0066] Preparation of Comparative Example 1:

[0067] The preparation methods of Comparative Example 1 and Sample 4 are the same, except that the components of the resin solution prepared in step (2) are different. In Comparative Example 1, the bisphenol A epoxy vinyl ester resin is replaced with unsaturated polyester resin in the resin solution.

[0068] The performance of Comparative Example 1 was tested and is shown in Table 1. By comparing Sample 4 with Comparative Example 1, the fiber volume content of Comparative Example 1 is higher than that of Sample 4, which makes the tensile strength, tensile modulus and tensile strength in the X direction of Comparative Example 1 significantly better than those in Sample 4. However, the density of Comparative Example 1 is significantly greater than that of Sample 4. Using direct yarn and bulky yarn can only improve the tensile strength of the product, but cannot reduce the density of the product.

[0069] Comparative Example 2

[0070] Preparation of Comparative Example 2:

[0071] The preparation methods of Comparative Example 2 and Sample 4 are the same, except that in step (1), only glass fiber bulk yarn is used to fix the copper wire, and the components of the resin solution prepared in step (2) are different. In Comparative Example 2, the bisphenol A epoxy vinyl ester resin is replaced with unsaturated polyester resin in the resin solution.

[0072] The performance of Comparative Example 2 was tested and is shown in Table 1. By comparing Sample 4 and Comparative Example 2, the fiber volume content of Comparative Example 2 is higher than that of Sample 4, which makes the tensile strength, tensile modulus and tensile strength in the X direction of Comparative Example 2 better than those in Sample 4. However, the density of Comparative Example 2 is significantly higher than that of Sample 4. Although the use of unsaturated polyester resin and bulky yarn improves the tensile strength of the product, the high fiber volume content per unit volume makes it impossible to reduce the density of the product.

[0073] Table 1 Performance test results of epoxy vinyl ester fiberglass wedge strips

[0074]

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an epoxy vinyl ester fiberglass wedge strip, characterized in that, The preparation steps include the following: S1, by weight, consists of 79.4-84.7 parts of bisphenol A epoxy vinyl ester resin, 1.7-2.5 parts of release agent, and 0.8-1.6 parts of accelerator, in sequence. Mix 2.4-4.1 parts of low-shrinkage agent, 8.2-11.8 parts of filler and 1.7-2.4 parts of curing agent, stir evenly and degas to obtain resin solution; S2 glass fiber direct yarn and glass fiber bulked yarn are drawn into a glue tank containing resin solution through a yarn separating plate and impregnated to obtain impregnated yarn; S3 The impregnated yarn is cured and shaped, and then cut into wedge strips of a specific length to obtain epoxy vinyl ester fiberglass wedge strips; In step S1, the curing agent includes a low-temperature curing agent and a high-temperature curing agent. The low-temperature curing agent is methyl isobutyl ketone peroxide, and the high-temperature curing agent is tert-butyl peroxide. The weight ratio of methyl isobutyl ketone peroxide to tert-butyl peroxide is 2:

1. In step S3, the impregnated yarn undergoes a two-stage curing process, firstly pre-curing and then a second curing. During the secondary curing process, the temperature of the front zone of the curing mold is 120-130℃, and the temperature of the rear zone is 150-160℃. The mixture of tert-butyl benzoate and methyl isobutyl ketone peroxide is used. Methyl isobutyl ketone peroxide decomposes rapidly at low temperatures, generating free radicals that initiate polymerization and release heat, causing the system temperature to rise. When the temperature reaches the critical decomposition temperature of tert-butyl benzoate, tert-butyl benzoate decomposes rapidly, generating a large number of free radicals that trigger a violent polymerization reaction.

2. The method for preparing the epoxy vinyl ester fiberglass wedge strip according to claim 1, characterized in that, The accelerator is an epoxy accelerator; The low-shrinkage agent is polyethylene wax powder.

3. The method for preparing the epoxy vinyl ester fiberglass wedge strip according to claim 2, characterized in that, In step S1, the stirring time is ≥5 min.

4. The method for preparing the epoxy vinyl ester fiberglass wedge strip according to claim 3, characterized in that, In step S2, both the direct glass fiber yarn and the bulked glass fiber yarn have a specification of 4800 tex.

5. The method for preparing the epoxy vinyl ester fiberglass wedge strip according to claim 4, characterized in that, In step S2, the traction speed is 0.15-0.3 m / min.

6. An epoxy vinyl ester fiberglass wedge strip obtained by the preparation method of any one of claims 1-5.

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