Glass fiber composition and glass fiber suitable for blades of large wind turbines

Abstract

This invention belongs to the field of glass fiber technology and specifically relates to a glass fiber composition and glass fibers suitable for blades used in large-scale wind turbines. The content of each component of the glass fiber composition, based on mass%, is as follows: SiO2: 57-62%, Al2O3: 16-21%, CaO: 0.4-4%, MgO: 13-18%, Fe2O3: 0.3-0.8%, Li2O: 0.1-0.7%, Y2O3: 0-2.5%, ZnO: 0.1-4.0%, B2O3: 0.3-0.8%, CeO2: 0.1-0.5%, and K2O + Na2O ≤ 0.5%, with the remainder being impurities. The glass fiber composition of this invention has a low density, a high elastic modulus of the manufactured glass fibers, and is more suitable for large-scale production requirements using tank kilns.

Description

[Technical Field]

[0001] This invention belongs to the field of glass fiber technology, and more specifically, relates to glass fiber compositions and glass fibers suitable for blades used in large-scale wind power generation. [Background technology]

[0002] With the transformation of the global energy structure and the growing awareness of environmental protection, offshore wind power has already become the cutting edge of global wind power development. Compared to onshore wind power, offshore wind power has the advantages of abundant resources, longer power generation time, no land occupancy, and suitability for large-scale development. In China, offshore wind power is also seen as a key area for the development of renewable energy, and is expected to enter a new stage of development within the period of the "14th Five-Year Plan". Accordingly, glass fiber is also developing in the direction of ultra-high modulus, low density, excellent fatigue properties, and corrosion resistance.

[0003] Low-density glass fibers with ultra-high modulus of elasticity effectively reduce blade weight, improve power generation efficiency, lower costs, and further promote the development of offshore wind power generation in large-scale offshore wind turbine blades.

[0004] Chinese Patent CN113929299A discloses high modulus glass compositions, high modulus glass fibers, and composite materials, which obtain high modulus glass fiber compositions with an elastic modulus of 94-101 GPa by introducing 3-15% rare earth oxides and 0.1-2% ZrO2. Because a large amount of rare earth oxides and ZrO2 are introduced, the density is generally 2.66 g / cm³. 3 This exceeds the required weight and is therefore unsuitable for the needs of large-scale offshore wind turbine blades, where weight reduction is a key trend.

[0005] Chinese patent CN116282934A discloses a high-magnesium, high-specific modulus glass fiber composition, which, by adjusting the MgO / Al2O3 ratio, yields glass fibers with an elastic modulus of 95-98.5 GPa. However, in blades for large offshore wind turbines, this glass fiber composition still cannot adequately replace carbon fiber.

[0006] Currently, in low-density, high-modulus glass fiber components, these components are generally located in the cordierite or enstatite main phase region of the MgO-Al2O3-SiO2 ternary phase diagram, exhibiting strong crystallization capabilities. In large-scale production processes using tank kilns, a series of problems are encountered, including reverse creeping of bushing plates, clogging of nozzles due to crystallized particles, severe deformation of bushing plates, and short service life of bushing plates.

[0007] Regarding the above issues, there is an urgent need to develop a low-density, high-modulus glass fiber composition suitable for large-scale wind turbine blades, which possesses excellent mechanical properties, weak crystallization ability, small crystallized particles, and is suitable for large-scale production using tank kilns. [Overview of the project] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide a glass fiber composition suitable for large wind turbine blades. The glass fiber composition has a low density, a high elastic modulus, adjusts the glass components, adds oxides such as ZnO, Li2O, and B2O3, and adjusts the ratio of cross-linked oxygen to non-cross-linked oxygen in the glass to improve the network structure of the glass, effectively improve the elastic modulus of the glass, and deviate the glass components from the main phase region of cordierite and the main phase region of enstatite in the MgO-Al2O3-SiO2 ternary phase diagram. However, the crystallization on the high-temperature side of the glass still mainly occurs with cordierite, the crystallization activation energy increases, and the crystallization ability of the glass is reduced, so that it can meet the requirements of large-scale production by a tank furnace. Further, the present invention provides glass fibers produced from a glass fiber composition suitable for large wind turbine blades.

Means for Solving the Problems

[0009] The content of each component of the glass fiber composition suitable for large wind turbine blades described in the present invention is based on mass%, SiO2: 57 to 62%, Al2O3: 16 to 21%, CaO: 0.4 to 4%, MgO: 13 to 18%, Fe2O3: 0.3 to 0.8%, Li2O: 0.1 to 0.7%, Y2O3: 0 to 2.5%, ZnO: 0.1 to 4.0%, B2O3: 0.3 to 0.8%, CeO2: 0.1 to 0.5%, K2O + Na2O ≤ 0.5%, and the balance is impurities.

[0010] Here, The mass% of ZnO and Al2O3 satisfies ZnO / Al2O3 = 0.02 to 0.35, The content of the mass% of Li2O + ZnO and B2O3 satisfies (Li2O + ZnO) / B2O3 ≥ 1.0, The content of the mass% of CeO2 and Fe2O3 satisfies CeO2 / Fe2O3 ≥ 0.3, The content of the mass% of Y2O3 and ZnO satisfies Y2O3 + ZnO: 1.0 to 5.0%.

[0011] The density of the glass fiber composition suitable for the large wind turbine blade ≤ 2.61 g / cm3 It is as follows.

[0012] The properties of the glass fiber manufactured from the glass fiber composition suitable for the large wind power blade are as follows.

[0013] The forming temperature of the glass fiber is 1280 - 1330 °C.

[0014] The specific modulus of elasticity of the glass fiber is 3.80×10 6 m or more.

[0015] The modulus of elasticity of the glass fiber is 98.7 GPa or more.

[0016] The liquidus temperature of the glass fiber is 1310 °C or less.

[0017] The glass fiber composition suitable for the large wind power blade described in the present invention is manufactured from quartz powder, calcined kaolin, dolomite, magnesium oxide, colemanite, yttrium oxide, zinc oxide, cerium oxide, rhodonite, sodium sulfate and lithium slag waste. Here, by introducing a sufficient amount of Al2O3 with calcined kaolin and introducing a sufficient amount of Fe2O3, the cost of the glass fiber composition is effectively reduced. In the present invention, since a small amount of TiO2 is inevitably introduced, Li2O is introduced by using lithium slag waste instead of some rhodonite, thereby greatly reducing the raw material cost and enabling the utilization of solid waste, which is in line with China's carbon peak and carbon neutral policies.

[0018] SiO2 is an important glass-forming oxide, forming a three-dimensional skeletal structure in which the vertex angles of silicon-oxygen tetrahedra [SiO4] are linked. The Si-O bond is a polar covalent bond with strong bond strength, and ionic and covalent bonds each account for 50%. SiO2 can improve the chemical stability and mechanical strength of glass. However, high SiO2 content requires a high melting temperature, increases the difficulty of fiber formation, and can even cause quartz crystallization. In this invention, the SiO2 content is limited to a range of 57-62%.

[0019] Al2O3 is an intermediate oxide and has multiple coordination types in the network structure of glass. When there is little free oxygen in the glass, aluminum oxygen octahedra [AlO6] are formed in the gaps of the network, and when there is a sufficient amount of free oxygen, Al 3+ The structure is strengthened by removing non-crosslinked oxygen and reconnecting the network that was severed by R2O. An appropriate amount of Al2O3 can reduce the crystallization tendency of the glass and improve its chemical stability and mechanical strength. However, if introduced in excess, it increases the high-temperature viscosity of the glass and strengthens the crystallization tendency of cordierite. In this invention, the Al2O3 content is limited to 16-21%.

[0020] CaO is an external component of the network, and its coordination number is generally 6. At high temperatures, Ca 2+ Because its aggregation effect is weak and its polarization ability is strong, the high-temperature viscosity of the glass decreases. CaO can shorten the material properties of the glass, which is advantageous for large-scale production using tank furnaces, but Ca 2+ If the content is too high, the brittleness of the glass increases. 2+ Ions have a large radius, low electric field strength, and weak aggregation effect, and primarily provide free oxygen within the glass, reducing the degree of bonding in the silicon-oxygen skeleton and thus lowering the elastic modulus of the glass. In this invention, the CaO content is limited to 0.4 to 4%.

[0021] MgO is an alkaline earth metal oxide. As an oxide of the external components of the network in glass, it does not participate in the network and has a low strength of a single ionic bond. Mg 2+ ions in the glass, on the one hand, provide free oxygen to reduce the degree of bonding of the silicon-oxygen skeleton, and on the other hand, are located at the places where the bonds are broken to repair the broken places of the silicon-oxygen network. Mg 2+ ions have a small radius, a large electric field strength, a stronger aggregation effect, aggregate the broken network, make the structure of the glass network more compact, and effectively improve the elastic modulus of the glass. In the present invention, the content of MgO is limited to 13-18%.

[0022] Fe2O3 mainly exists in the glass network in two ionic forms of Fe 2+ and Fe 3+ . Fe 2+ acts as a network modifier to cut some [SiO4] and [AlO4] tetrahedrons, destroy the network structure of the glass, and can reduce the mechanical properties of the glass. Fe 3+ can form a triangular pyramid-shaped network structure, and by aggregating the network structure that strengthens the glass, increase the degree of bonding of [SiO4] and [AlO4], and improve the elastic modulus of the glass. By introducing an appropriate amount of Fe2O3 and increasing the value of the ratio of Fe 3+ / Fe 2+ , the elastic modulus of the glass can be effectively improved. However, excessive Fe2O3 will affect the heat permeability of the glass liquid, which is disadvantageous for large-scale production by tank furnaces. In the present invention, the content of Fe2O3 is limited to 0.3-0.8%.

[0023] Na2O and K2O are oxides of the external components of the glass. Among them, R +Na2O and K2O are located in the vacancies of the glass structure network, providing free oxygen, which can reduce the Si / O ratio and increase the content of non-crosslinked oxygen. The appearance of non-crosslinked oxygen disrupts the silicon-oxygen network, and its excess charge is neutralized by alkali metal ions, causing the silicon-oxygen tetrahedron to lose its original integrity and symmetry, resulting in a sparser glass structure and poor physical performance. However, appropriate amounts of Na2O and K2O can effectively reduce the high-temperature resistivity of glass, which is advantageous for the utilization rate of electric melting auxiliary systems during large-scale production using tank furnaces, improving glass melting quality and helping to improve the fiberization efficiency of glass fibers. In this invention, the content of K2O + Na2O is limited to ≤0.5%.

[0024] Li2O, like Na2O and K2O, is an oxide that is an external component of the network, but its role within glass is relatively unique. When the Si / O ratio is high, it mainly provides free oxygen, increases the content of non-crosslinked oxygen, breaks bonds, destroys the integrity of the glass network structure, and has a strong melting aid effect. When the Si / O ratio is low, Li + The radius is K + na + Because it is smaller than the radius, the electric field strength is greater, which mainly manifests as an aggregation effect, and can not only make the network structure of the glass tighter but can also effectively reduce the crystallization tendency of the glass. However, a large amount of Li2O will increase the crystallization tendency of the glass. In this invention, the Li2O content is limited to 0.1 to 0.7%.

[0025] B2O3 is a network-forming compound, with boron-oxygen triangularities [BO3] and boron-oxygen tetrahedra [BO4] as its structural units. In borosilicate glass, it forms a structural network together with silicon-oxygen tetrahedra, and the higher the proportion of [BO4], the more robust the network structure becomes. Adding a small amount of B2O3 can lower the high-temperature viscosity of the glass, which is advantageous for clarification. If the content is too high, the proportion of [BO3] increases, causing boron anomalies and degrading the physical performance of the glass. In this invention, the B2O3 content is limited to 0.3-0.8%.

[0026] Y2O3 functions as an external network component within the glass, providing free oxygen and reducing the degree of bonding between [SiO4] tetrahedra. 3+ It fills the gaps in the network, forming a [YO7] coordinate with non-crosslinked oxygen, thereby increasing the degree of bonding of the network structural units of the glass. When an appropriate amount of Y2O3 is introduced, most Y 3+ Y2O3 is distributed in the gaps of the glass network structure, causing the glass network structure to bond tightly and effectively improving the elastic modulus of the glass. Excess Y2O3 worsens the degree of fracture of the network structure and tightens the network structure. 3+ Because its effect is limited, the elastic modulus of the glass decreases. In this invention, the Y2O3 content is limited to 0-2.5%.

[0027] CeO2, as a powerful oxidizing agent, releases oxygen at high temperatures, promoting the removal of bubbles in the glass liquid. CeO2 can effectively replace sodium sulfate (Na2SO4) in glass. + This invention reduces the introduction of [unclear], as well as the generation of SO2 gas during the glass melting process, thereby mitigating corrosion of refractory materials and lowering the SO2 content in exhaust gases emitted from the kiln, thus aligning with China's "carbon peak-out, carbon neutrality policy." In this invention, the CeO2 content is limited to 0.1-0.5%.

[0028] ZnO generally forms zinc oxygen octahedra [ZnO6] as an oxide component of the external network structure. When there is sufficient free oxygen in the glass, it can form zinc oxygen tetrahedra [ZnO4] and enter the glass network structure, making the glass structure more stable and improving the elastic modulus of the glass. However, the introduction of ZnO into glass usually leads to the crystallization of zinc aluminum sequester (ZnAl2O4) and quartz. Zinc aluminum sequester has a melting point of 1950°C, making it difficult to melt, which can severely clog nozzles and affect wire drawing operations. Furthermore, zinc aluminum sequester can lead to the concentration of chromium in the three-phase interface region, resulting in the formation of chromium magnesium sequester. Quartz crystallization usually floats on the surface of the glass liquid in the work passage, and once formed, it is extremely difficult to process. It also further promotes the crystallization of zinc aluminum sequester in the nozzle, severely affecting wire drawing operations. In this glass system, the low CaO content results in a stronger crystallization ability of cordierite. Therefore, in this invention, by introducing ZnO and adjusting the ratio of ZnO to Al2O3, crystallization of zinc-aluminum spinite and quartz is prevented. Furthermore, the glass component is deviated from the central region of cordierite in the MgO-Al2O3-SiO2 ternary phase diagram, increasing the crystallization activation energy of cordierite, suppressing its crystallization ability, reducing the crystallization rate, and minimizing the tendency of the glass to crystallize cordierite. Even if cordierite crystallized particles are generated during the stringing process, their low crystallization tendency results in a high crystallization activation energy, preventing rapid growth of the cordierite crystallized particles and thus preventing reverse creeping or string scattering of the bushing plate. 2+ As a high-electric-field-strength ion, it can induce the conversion from 4-coordinate [AlO4] to 5-coordinate [AlO5], and [AlO5], by binding to 3-coordinate oxygen Q3, makes the network structure of the glass denser and effectively improves the elastic modulus of the glass. If too much ZnO is used, the glass becomes prone to crystallization, so in this invention, the ZnO content is limited to 0.1-4.0%, and the ZnO / Al2O3 ratio is limited to 0.02-0.35.

[0029] In conventional glass systems, the introduction of B2O3 can effectively reduce the density of the glass, but the three-coordinate [BO3] has poor stability and significantly reduces the elastic modulus of the glass fibers. In the present invention, both the introduced Li2O and ZnO induce the conversion from [BO3] to [BO4], thereby effectively improving the elastic modulus of the fibers. However, excess Li2O significantly reduces the surface tension of the glass liquid, making it unfavorable for stringing operations and potentially causing reverse creeping of crystallization, while excess ZnO causes crystallization of zinc-aluminum spinite and quartz. In this invention, by adjusting the ratio of Li2O + ZnO and B2O3, the synergistic effect of Li2O and ZnO is fully realized, maximizing the conversion from [BO3] to [BO4], while avoiding excessively low surface tension in the glass liquid, an increase in the crystallization limit, and the occurrence of boron anomalies. This reduces the density of the glass, improves the elastic modulus of the fibers, and does not adversely affect the stringing process. In this invention, the ratio is limited to (Li2O + ZnO) / B2O3 ≥ 1.0.

[0030] In this invention, Al2O3 is introduced by calcined kaolin, and since lithium slag waste is used, some Fe2O3 is inevitably introduced. Normally, if the Fe2O3 level is too high, the FeO content in the glass becomes high, which seriously affects the heat permeability of the glass liquid in the tank furnace and affects the melting quality of the glass liquid. In this invention, an appropriate amount of CeO2 is introduced, and through its strong oxidizing effect, Fe 2+ From Fe 3+ By promoting the conversion to this, the thermal permeability of the glass liquid is effectively improved, which is advantageous for large-scale production using tank kilns. On the other hand, the FeO content decreases, and Fe 3+ / Fe 2+ As the ratio of Fe increases, CeO2 2+ From Fe 3+ Inducing a conversion to Fe 3+By increasing the content of [SiO4] and raising the degree of bonding between [AlO4], the elastic modulus of the glass can be effectively improved. In this invention, the ratio of CeO2 / Fe2O3 is limited to ≥ 0.3.

[0031] In this invention, the density of the glass is influenced by the molar mass of the glass oxide component and the internal structure of the glass itself. ZnO and Y2O3 have large molar masses, and the Y2O3 present in the gaps of the glass network is also affected. 3+ Because the ions have a high electric field strength effect, the glass structure becomes denser, significantly improving the density of the glass. In this invention, the Y2O3 + ZnO content is limited to 1.0-5.0%. [Effects of the Invention]

[0032] The beneficial effects of the present invention are as follows:

[0033] In this invention, in order to reduce production costs, Al2O3 is introduced from calcined kaolin and lithium slag waste is used, but the introduced Fe2O3 is usually treated as a harmful elemental impurity that affects the thermal permeability of glass in conventional high modulus formulations. In this invention, an appropriate amount of CeO2 is introduced, Fe 2+ From Fe 3+ Promote the conversion to Fe 3+ / Fe 2+ This increases the ratio and effectively improves the elastic modulus of the glass.

[0034] This invention promotes the conversion from [BO3] to [BO4] by introducing appropriate amounts of Li2O and ZnO, effectively reducing the density of the glass and improving the elastic modulus of the glass fibers.

[0035] This invention relates to a glass system of SiO2, Al2O3, CaO, and MgO, to which an appropriate amount of Li is added. 2+ , Y 3+By introducing ions with high electric field strength, their aggregation effect can be fully utilized, tightening the network structure of the glass, improving the elastic modulus, and increasing the crystallization activation energy of the glass system. This increases the crystallization barrier, reduces the tendency of the glass to crystallize, lowers the liquidus temperature of the glass, and is advantageous for large-scale production using tank furnaces.

[0036] In conventional technology, in order to improve the elastic modulus of glass, large amounts of Al2O3 and MgO are introduced while the CaO content is reduced. This results in an extremely strong tendency for cordierite crystallization in glass fibers, which is disadvantageous for large-scale production using tank kilns. In this invention, an appropriate amount of ZnO is introduced, while Zn 2+ By removing free oxygen provided by R2O and RO from the glass, zinc oxygen tetrahedra [ZnO4] are formed, reconnecting the network structure that was severed by R2O. This strengthens the network structure of the glass and improves its elastic modulus. On the other hand, ZnO enhances the crystallization tendency of zinc aluminum spinite and quartz, causing the glass components to deviate from the center of the cordierite phase region in the MgO-Al2O3-SiO2 ternary phase diagram, suppressing cordierite crystallization, and also preventing the appearance of crystallized zinc aluminum spinite and quartz near the liquidus temperature.

[0037] In this invention, when introducing an appropriate amount of ZnO, Zn 2+ This demonstrates that it is possible to induce a conversion from 4-coordinate [AlO4] to 5-coordinate [AlO5], and [AlO5], by binding to 3-coordinate oxygen Q3, makes the network structure of the glass denser and effectively improves the elastic modulus of the glass. In this invention, the effect of Al2O3 on improving the elastic modulus in glass fibers is maximized by adjusting the ratio of ZnO and Al2O3.

[0038] In this invention, by controlling the introduction of elements with large molar mass, a density of ≤2.61 g / cm³ can be achieved. 3By obtaining a glass fiber composition and further controlling the elemental ratio, the proportion of non-crosslinked oxygen in the glass is reduced, and the network structure of the glass is strengthened, resulting in a glass fiber composition with an elastic modulus of ≥98.7 GPa and a specific modulus of ≥3.80 × 10⁻¹⁰. 6 Make it m.

[0039] The glass fiber composition suitable for large wind turbine blades provided in this invention has a molding temperature range of 1280 to 1330°C, a liquidus temperature of the glass fiber provided in this invention not exceeding 1310°C, and a difference of ΔT between the molding temperature and the liquidus temperature of ΔT > 0°C. By adjusting the crystallization type, crystallization rate, crystallization activation energy, and manufacturing process, even with a small working window temperature ΔT, the glass fiber composition still does not crystallize during production, satisfies the requirements of the stringing process, and enables mass production in large tank kilns. [Modes for carrying out the invention]

[0040] The present invention will be described and explained in detail below with reference to examples.

[0041] The production process for the glass fiber composition suitable for large wind turbine blades in the present invention is as follows: (1) The steps include: calculating the mass of various raw materials required according to the content of each component, weighing each raw material and mixing them uniformly with air pressure, then sending them to the silo at the top of the kiln to obtain the mixture, and then using a raw material feeder to feed the mixture into the kiln furnace of the large tank kiln at a uniform speed, (2) The mixed mixture is melted in the kiln of a tank kiln at 1450-1550°C and clarified into a homogeneous glass liquid, (3) The glass liquid is drawn through a nozzle in a platinum-rhodium bushing plate at 1280-1330°C to form glass fibers, (4) The process includes passing glass fibers through an oiling device to coat them with a sizing agent, pulling them and winding them onto a spinning machine, and then spinning them to form a yarn product.

[0042] The present invention also provides a production process for glass fiber compositions suitable for large wind turbine blades, and improves the bushing plate and stringing processes to mitigate the reverse creeping phenomenon of bushing plates, extend the service life of bushing plates, and improve the production efficiency of glass fibers.

[0043] In this invention, in order to achieve large-scale production using a tank kiln, the following modifications are made to the bushing plate and the stringing process, while keeping the working window temperature △T low and meeting the requirements of the stringing process.

[0044] (1) The nozzle hole diameter is reduced from 1.8 mm to 1.3 mm, and the nozzle length is extended from 3.2 mm to 3.6 mm to suppress the crystallization tendency of the glass liquid in the nozzle and improve the reverse creeping phenomenon of the glass liquid during stringing.

[0045] (2) After the glass liquid has formed into a thread-like structure, it is rapidly cooled to avoid the formation of crystallized particles. This is achieved by increasing the airflow from the air conditioner from the original 15 m / s to 22 m / s, and by replacing the solid cooling sheet with a hollow water-cooled cooling sheet to enhance the cooling capacity of the bushing plate, shorten the cooling time after the glass fiber is formed, suppress the formation of crystallized particles during the threading process, and thereby improve production efficiency.

[0046] (3) When the hole diameter of the bushing plate is small, the nozzle length is long, and the temperature of the bushing plate is high, the bushing plate is inevitably prone to deformation and damage, and in particular, cracks are likely to occur in the electrode area, causing material leakage. Therefore, by increasing the thickness of the electrode from the original 5 mm to 10 mm and using bushing plate reinforcing ribs, deformation and damage to the bushing plate due to high temperature can be effectively mitigated, and the service life of the bushing plate can be extended.

[0047] When verifying the overall performance of glass fibers in the examples and comparative examples, the following parameters are selected.

[0048] 1) Molding temperature: This is the temperature at which the viscosity of the glass is 1000 Poise, and can represent the molding temperature for fiberization. The high-temperature viscosity of the glass is measured using a high-temperature viscometer.

[0049] 2) Liquidus temperature: This is the critical temperature at which glass begins to crystallize, and is generally the upper limit of the crystallization temperature of glass. The upper limit of the crystallization temperature of glass is obtained using a crystallization furnace.

[0050] 3) ΔT: This is the difference between the molding temperature and the liquidus temperature.

[0051] 4) Crystallization type: Measured using an X-ray diffractometer.

[0052] 5) State of crystallized particles: Use a polarizing microscope. Unit area (1 mm) 2 The evaluation grade based on the number of crystal grains within the parentheses is dense (>15 grains), moderate (5-15 grains), and small (<5 grains). The evaluation grade based on the size of the crystal grains is large (>50 μm), moderate (20-50 μm), and small (<20 μm).

[0053] 6) Glass density: The glass density shall be tested according to the standard test method for measuring glass density using the ASTM C693 buoyancy method.

[0054] 7) Modulus of elasticity: Test according to ASTM D2343 standard.

[0055] 8) Specific modulus of elasticity: The ratio of the elastic modulus to the density of a material. Specific modulus of elasticity = elastic modulus / (density * 9.8), unit is 10 6 It is m.

[0056] (Examples 1-8) The content and performance indicators of the glass fiber compositions in Examples 1 to 8 are shown in Table 1. [Table 1]

[0057] Comparative Examples 1-6 The content and performance indicators of the glass fiber compositions for Comparative Examples 1 to 6 are shown in Table 2. [Table 2]

[0058] The glass fiber compositions of Examples 1-8 and Comparative Examples 1-6 inevitably contain impurities, and the remainder of the blending amount is the content of these impurities.

[0059] As can be seen from the above, in Examples 1 to 8, the introduction of appropriate amounts of Li2O and ZnO promotes the conversion from [BO3] to [BO4], effectively reducing the glass density and improving the elastic modulus of the glass fibers.

[0060] In Comparative Examples 1-3, one of Li2O, ZnO, or B2O3 is missing, making large-scale production using tank kilns difficult in all cases.

[0061] In Comparative Examples 4 and 5, the mass percentages of ZnO and Al2O3 were 0.015 and 0.4, respectively, which are outside the range of ZnO / Al2O3 = 0.02 to 0.35. Therefore, the effect was not good, and it was difficult to realize large-scale production using tank kilns.

[0062] In Comparative Example 6, the mass percentage content of Li2O+ZnO and B2O3 did not satisfy (Li2O+ZnO) / B2O3 ≥ 1.0, being only 0.83. Similarly, the effect was not good, making it difficult to realize large-scale production using tank kilns.

[0063] As described above, Comparative Examples 1 to 6 all failed to achieve the objective of the present invention, whereas Examples 1 to 8 had a density of ≤ 2.61 g / cm³. 3 By obtaining a glass fiber composition and controlling the elemental ratio, the network structure of the glass is strengthened, resulting in a glass fiber with an elastic modulus of ≥98.7 GPa and a specific modulus of ≥3.80 × 10⁻¹⁰. 6 Make it m.

Claims

1. The content of each component is expressed in mass percent. SiO ２ : 57 - 62%, Al ２ O ３ : 16 - 21%, CaO: 0.4 - 4%, MgO: 13 - 18%, Fe ２ O ３ : 0.3 - 0.8%, Li ２ O: 0.1 - 0.7%, Y ２ O ３ : 0 - 2.5%, ZnO: 0.1 - 4.0%, B ２ O ３ : 0.3 - 0.8%, CeO ２ : 0.1 - 0.5%, K ２ O + Na ２ O ≤ 0.5%, and the balance is impurities, ZnO and Al ２ O ３ The mass percentage is ZnO / Al ２ O ３ = satisfies 0.02 to 0.35, Li ２ O + ZnO and B ２ O ３ The mass % content is (Li ２ (O + ZnO) / B ２ O ３ Satisfying ≥ 1.0, CeO ２ and Fe ２ O ３ The mass percentage content is CeO ２ / Fe ２ O ３ Satisfying ≥ 0.3, A glass fiber composition suitable for blades used in large-scale wind turbines, characterized by the following features.

2. Y ２ O ３ The mass percentage content of ZnO is Y ２ O ３ +ZnO: satisfies 1.0-5.0%, A glass fiber composition suitable for large wind turbine blades as described in feature 1.

3. The density is 2.61 g / cm³. ３ The following is: A glass fiber composition suitable for large wind turbine blades as described in feature 1.

4. Glass fibers manufactured from a glass fiber composition suitable for large wind turbine blades according to any one of claims 1 to 3, The molding temperature is 1280-1330°C. Glass fibers manufactured from a glass fiber composition suitable for blades of large wind turbines, characterized by the following features.

5. The specific modulus is 3.80 × 10⁻⁶. ６ m or more Glass fibers manufactured from a glass fiber composition suitable for large wind turbine blades as described in feature 4.

6. The modulus of elasticity is 98.7 GPa or higher. Glass fibers manufactured from a glass fiber composition suitable for large wind turbine blades as described in feature 4.

7. The liquidus temperature is 1310°C or lower. Glass fibers manufactured from a glass fiber composition suitable for large wind turbine blades as described in feature 4.

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