Preparation method of glass fiber mat, glass fiber mat composite board and preparation method of glass fiber mat composite board

Abstract

The invention relates to a preparation method of a glass fiber mat, a glass fiber mat composite board and a preparation method of the glass fiber mat composite board. The preparation method of the glass fiber mat comprises the following steps: sequentially carrying out crushing and airflow separation treatment on waste glass fiber products to obtain regenerated glass fibers; the preparation method comprises the following steps: uniformly mixing regenerated glass fibers and raw glass fibers to obtain a material A, then laying the material A through airflow, spraying a dispersing agent solution, and depositing to obtain an initial fiber web; and spraying a polyurethane adhesive on the initial fiber web, and heating and curing to obtain the glass fiber mat. The resin concentration is diluted through the native glass fibers, and meanwhile the blocking and supporting effects are achieved; dispersing epoxy resin particles by means of castor oil and / or hydroabietinol; and the polyurethane adhesive reacts with the residual epoxy resin, castor oil and / or hydrogenated abietinol, so that the bonding strength between the fibers is enhanced, and efficient recycling of the waste glass fiber product is realized.

Description

Technical Field

[0001] This application relates to the field of recycling and processing waste glass fiber products, specifically to a method for preparing glass fiber mat and a glass fiber mat composite board and its preparation method. Background Art

[0002] Fiberglass materials, with their high strength, corrosion resistance, and design flexibility, are widely used in construction, transportation, wind power, and other fields. However, with the surge in consumption of fiberglass products, the recycling and disposal of waste fiberglass products (such as decommissioned wind turbine blades and discarded composite material components) has become an industry challenge. Traditional disposal methods, such as landfilling or incineration, not only waste fiberglass resources but may also cause environmental problems such as soil and air pollution.

[0003] Waste fiberglass products often contain impurities such as epoxy resin that are difficult to remove, which pose multiple obstacles to the recycling of waste fiberglass products: Incompletely removed epoxy resin will disrupt the uniform distribution between fibers, leading to stress concentration and making the felt easy to break or deform; If the amount of epoxy resin residue is high, the flexibility of the fiberglass will be reduced, resulting in poor bulkiness and elasticity of the fiberglass felt, affecting its lay-up and adhesion in composite materials; Residual epoxy resin may undergo secondary curing or decomposition at high temperatures, releasing gases (such as water vapor, small molecule organic matter, etc.), causing pores or delamination inside the fiberglass felt, reducing its heat resistance and stability, etc.

[0004] How to achieve the recycling of waste glass fiber while endowing the recycled material with excellent comprehensive properties has become a key technological challenge in the field of circular economy of materials. Summary of the Invention

[0005] To address the issue of recycling waste glass fiber, this application proposes a method for preparing glass fiber mat and a glass fiber mat composite board and its preparation method.

[0006] In a first aspect, this application provides a method for preparing glass fiber mat, which adopts the following technical solution: A method for preparing a glass fiber mat includes the following steps: Pretreatment: Waste glass fiber products are crushed and then air-separated to obtain recycled glass fiber; Deposition into a web: The recycled glass fiber and the virgin glass fiber are mixed evenly to obtain material A. Then, material A is spread into a web by airflow while a dispersant solution is sprayed, and the initial fiber web is deposited. Fabrication: Polyurethane adhesive is sprayed onto the initial fiber web and heated to cure to obtain glass fiber mat; The mass ratio of the recycled glass fiber to the virgin glass fiber is 7:(2-3); The dispersant in the dispersant solution is at least one of castor oil and hydrogenated rosin alcohol.

[0007] By adopting the above technical solution, recycled glass fiber is mixed with virgin glass fiber. The surface of the virgin glass fiber is clean and free of epoxy resin residue. The addition of recycled glass fiber can physically dilute the epoxy resin content in the recycled fiber, reduce the concentration of resin impurities per unit volume, and also act as an "isolation body" interspersed between the recycled glass fibers, playing a physical barrier and support role, preventing the epoxy resin on the surface of the recycled glass fiber from sticking together, improving the sliding properties between fibers, and avoiding fiber agglomeration caused by epoxy resin residue.

[0008] Castor oil and hydrogenated rosin alcohol are both amphiphilic molecules that can be adsorbed onto the surface of recycled and virgin glass fibers, forming a molecular layer that isolates resin particles. Through electrostatic repulsion and steric hindrance, they prevent epoxy resin particles from agglomerating, ensuring that they are evenly dispersed between fibers. This avoids stress concentration caused by excessively high local epoxy resin concentration, thereby improving the fracture toughness of the glass fiber mat.

[0009] Polyurethane adhesives contain isocyanate groups, which can react with the hydroxyl groups in epoxy resin to form chemical bonds, "fixing" the residual resin between the fibers and inhibiting its secondary curing or decomposition at high temperatures. At the same time, polyurethane adhesives penetrate into the interfacial gaps between glass fibers and epoxy resin to form an interpenetrating network structure, which bonds the discrete glass fibers and epoxy resin particles into a whole, improving the fracture resistance of the glass fiber mat.

[0010] The isocyanate groups in polyurethane adhesives can also react chemically with some of the hydroxyl groups in castor oil and / or hydrogenated rosin alcohol molecules to form urethane bonds. This can significantly enhance the interfacial bonding strength between recycled glass fibers and virgin glass fibers and polyurethane, compensate for the weak interfiber bonding caused by epoxy resin residue, effectively inhibit the propagation of microcracks at the interface, and improve the mechanical properties and aging resistance of glass fiber mats.

[0011] This application achieves efficient recycling of waste glass fibers by mixing recycled glass fibers with virgin glass fibers. The virgin glass fibers physically dilute the resin concentration and simultaneously act as a barrier and support. The epoxy resin particles are dispersed by the electrostatic repulsion and steric hindrance effect of castor oil and / or hydrogenated rosin alcohol. A polyurethane adhesive is then used to chemically react with the residual epoxy resin, castor oil, and / or hydrogenated rosin alcohol to form a chemically bonded and interpenetrating network structure, which enhances the bonding strength between fibers and effectively improves the mechanical properties and aging resistance of the glass fiber mat.

[0012] Preferably, the dispersant is castor oil.

[0013] By adopting the above technical solution, castor oil contains C18 long-chain fatty acids in its molecular structure. Its non-polar structure is similar to the soft segments in polyurethane molecular chains, allowing castor oil to interact with polyurethane molecular chains through van der Waals forces to form physical entanglements, thereby playing an internal plasticizing role and significantly improving the toughness of glass fiber mat. The oily groups of castor oil can penetrate into the interface gaps between epoxy resin and recycled glass fiber, weakening the adhesion of epoxy resin to recycled glass fiber, while reducing the surface tension of the resin, making it easier for residual epoxy resin to be dispersed in the subsequent airflow web formation process, thus improving the uniformity and continuity of the initial fiber web. Therefore, castor oil is the preferred choice.

[0014] Preferably, the dispersant is a mixture of castor oil and hydrogenated rosin alcohol.

[0015] By adopting the above technical solution, when the dispersant includes both castor oil and hydrogenated rosin alcohol, the flexible segments of castor oil impart toughness to the glass fiber mat, while its oily groups penetrate into the interface between epoxy resin and glass fiber, reducing the adhesion of epoxy resin and improving dispersibility; the hydrogenated rosin alcohol molecule contains a rigid ring structure and hydroxyl groups, and its polar groups further disperse resin particles through electrostatic repulsion. At the same time, the rigid rings can be embedded in the gaps between glass fibers, enhancing the physical support between fibers and inhibiting stress concentration caused by local enrichment of epoxy resin, thereby improving the tensile strength of the glass fiber mat.

[0016] Preferably, the mass ratio of castor oil to hydrogenated rosin alcohol is 10:(3-5).

[0017] By adopting the above technical solution, when the content of hydrogenated rosin alcohol is too low, it is difficult for hydrogenated rosin alcohol to provide rigid support for glass fiber mat, and the effect on improving the tensile strength of glass fiber mat is not obvious; when the content of hydrogenated rosin alcohol is too high, the content of castor oil is relatively too low, and castor oil is difficult to improve the toughness of glass fiber mat. Therefore, after a lot of research and experimental verification, the applicant finally determined that the mass ratio of castor oil to hydrogenated rosin alcohol in this application is as described above.

[0018] Preferably, in the felt-making step, the polyurethane adhesive and nanofiller are first uniformly mixed to obtain material B, and then material B is sprayed onto the initial fiber web and heated and cured to obtain glass fiber felt.

[0019] By adopting the above technical solution, the nanofiller possesses a large specific surface area and high surface activity, enabling it to tightly bond with polyurethane adhesives and construct more physical or chemical crosslinking points. This further consolidates the role of the polyurethane adhesive in "fixing" residual epoxy resin, while simultaneously enhancing the chemical bonding and physical entanglement between glass fibers, effectively improving the mechanical properties of the glass fiber mat. Furthermore, due to pretreatment processes such as crushing, recycled glass fibers and residual epoxy resin often have defects such as microcracks and pores on their surfaces. The nanofiller can embed itself into these defects through physical filling, forming an "anchoring" effect, increasing the contact area between the polyurethane adhesive and the recycled glass fibers and epoxy resin, and further enhancing interfacial bonding.

[0020] Preferably, the nanofiller includes at least one of nano-titanium dioxide and nano-zirconia.

[0021] By adopting the above technical solutions, both nano-titanium dioxide and nano-zirconia have extremely high specific surface areas, which can form a large number of physical cross-linking points with polyurethane adhesives, significantly improving the cohesive strength of the adhesive network, thereby enhancing the tensile strength of glass fiber mat.

[0022] Preferably, the nanofiller is nano-titanium dioxide.

[0023] By adopting the above technical solution, the spherical or near-spherical structure of nano-titanium dioxide can play a "ball effect" in the fiber network. When the material is subjected to external force, the rolling of particles can relieve stress concentration. Combined with the flexible chain segments of castor oil, it can improve the toughness of glass fiber mat. At the same time, nano-titanium dioxide has extremely strong absorption and scattering ability of ultraviolet light, which can effectively inhibit the oxidation chain scission reaction of polyurethane adhesive caused by ultraviolet light irradiation and significantly delay the aging of glass fiber mat. Therefore, nano-titanium dioxide is preferred.

[0024] Preferably, the dispersant is hydrogenated rosin alcohol, and the mass ratio of hydrogenated rosin alcohol to nano-titanium dioxide is 10:(3-4).

[0025] By adopting the above technical solution, during the process of nano-titanium dioxide absorbing ultraviolet light to reduce the photo-oxidation of polyurethane, certain free radicals may be released, which attack the polyurethane molecular chain and cause degradation. The rigid tricyclic structure of hydrogenated rosin alcohol molecules has multiple active sites, which can specifically react with free radicals, quench the activity of free radicals, and inhibit the occurrence of this degradation.

[0026] When the content of nano-titanium dioxide is too low, its shielding effect against ultraviolet rays is not obvious, and it is difficult to fully utilize the "ball effect" to enhance toughness. When the content of nano-titanium dioxide is too high, excessive nano-titanium dioxide may release more free radicals, which will weaken the quenching ability of hydrogenated rosin alcohol to free radicals. Therefore, after extensive research and experimental verification, the applicant finally determined that the mass ratio of hydrogenated rosin alcohol to nano-titanium dioxide in this application is as described above.

[0027] Secondly, this application provides a glass fiber mat composite board, which adopts the following technical solution: A glass fiber mat composite board includes a first polyurethane layer, a glass fiber mat layer, and a second polyurethane layer, wherein the glass fiber mat layer is located between the first polyurethane layer and the second polyurethane layer. The glass fiber mat layer is prepared by the above-described method for preparing glass fiber mat.

[0028] By adopting the above technical solution, the glass fiber mat layer is prepared using polyurethane adhesive as the structural adhesive, which has good interfacial compatibility with both the first and second polyurethane layers, making the composite board layers firmly bonded and not easy to peel off.

[0029] Thirdly, this application provides a method for preparing a glass fiber mat composite board, which is used to prepare the above-mentioned glass fiber mat composite board, and adopts the following technical solution: A method for preparing a glass fiber mat composite board includes the following steps: Polyurethane material, glass fiber mat, and polyurethane material are stacked in sequence and then hot-pressed to form the glass fiber mat composite board.

[0030] By adopting the above technical solution, the preparation method only requires stacking the three materials in sequence and then hot-pressing them. The process steps are relatively simple, easy to operate and control, and can realize industrial production and improve production efficiency.

[0031] In summary, this application has the following beneficial effects: 1. This application mixes recycled glass fiber with virgin glass fiber, utilizing the virgin glass fiber to physically dilute the resin concentration while simultaneously acting as a barrier and support; disperses epoxy resin particles using the electrostatic repulsion and steric hindrance effect of castor oil and / or hydrogenated rosin alcohol; and chemically reacts with residual epoxy resin, castor oil, and / or hydrogenated rosin alcohol through polyurethane adhesive to form an interpenetrating network structure, enhancing the bonding strength between glass fibers, effectively improving the mechanical properties and aging resistance of glass fiber mat, and achieving efficient recycling of waste glass fiber; 2. This application mixes polyurethane adhesive and nanofiller. Through the tight combination of nanofiller and polyurethane adhesive, more cross-linking points are constructed. At the same time, nanofiller can be embedded in defects such as microcracks on the surface of recycled glass fiber and residual epoxy resin through physical filling, forming an "anchoring" effect, increasing the contact area between polyurethane adhesive and recycled glass fiber and epoxy resin, thereby effectively enhancing the mechanical properties of glass fiber mat. 3. By adding nano-titanium dioxide to absorb and scatter ultraviolet light, this application can significantly delay the aging of glass fiber mat; at the same time, multiple active sites in the rigid tricyclic structure of hydrogenated rosin alcohol molecules can specifically react with the free radicals released by nano-titanium dioxide after absorbing ultraviolet light, quench the activity of free radicals, and inhibit the degradation of polyurethane molecular chains caused by free radical attacks. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a glass fiber mat composite board according to this application.

[0033] Explanation of reference numerals in the attached drawings: 1. First polyurethane layer; 2. Glass fiber mat layer; 3. Second polyurethane layer. Detailed Implementation

[0034] The raw materials in this application include the following: Waste fiberglass products: This application uses wind turbine blade solid waste as an example for illustration; Virgin fiberglass: Commercially available product with CAS number 65997-17-3; Castor oil: Uses commercially available product with CAS number 8001-79-4; Hydrogenated rosin alcohol: Uses commercially available product with CAS number 13393-93-6; Polyurethane adhesive: The adhesive used is a brand manufactured by Covestro Polymers. DL's commercially available products; Nano titanium dioxide: using commercially available products with CAS number 13463-67-7; Nano-zirconia: Using commercially available products with CAS number 1314-23-4; Polyurethane: Commercially available products using polyurethane insulation boards manufactured by Jiangsu Luyuan New Materials Co., Ltd.; The present application will be further described in detail below with reference to embodiments and comparative examples.

[0035] Example 1 A method for preparing a glass fiber mat includes the following steps: Pretreatment: 1000g of wind turbine blade solid waste is crushed and then air-separated to obtain recycled glass fiber; Deposition and web formation: 700g of recycled glass fiber and 150g of virgin glass fiber are mixed evenly to obtain material A. Then, material A is spread into a web by airflow while spraying 200g of castor oil solution with a mass concentration of 15wt% (solvent is ethanol) to deposit the initial fiber web. Felt making: 100g of polyurethane adhesive is sprayed onto the initial fiber web and cured at 80℃ to obtain glass fiber felt.

[0036] Example 2-3 In Examples 2-3, based on the preparation method of Example 1, the total mass of recycled glass fiber and virgin glass fiber was kept at 850g, and the mass ratio of recycled glass fiber to virgin glass fiber was adjusted as shown in Table 1.

[0037] Comparative Example 1 Comparative Example 1 was prepared by directly laying 850g of recycled glass fiber through an airflow without mixing it with virgin glass fiber, while keeping all other conditions unchanged.

[0038] Table 1. Mass ratio and performance test results of recycled glass fiber and virgin glass fiber in Examples 1-3 and Comparative Example 1. Performance testing The glass fiber mats of Examples 1-3 and Comparative Example 1 were subjected to the following performance tests, and the test results are shown in Table 1: (1) Tensile strength The tensile strength of the glass fiber mat was tested according to the GB / T 17911-2006 test standard.

[0039] (2) Bending strength The flexural strength of the glass fiber mat was tested according to the GB / T 1449-2005 test standard.

[0040] Referring to Table 1, comparing Examples 1-3 and Comparative Example 1, it can be seen that the tensile strength and flexural strength of Examples 1-3 are higher than those of Comparative Example 1. This is because Comparative Example 1 lacks virgin glass fibers, making it impossible to physically dilute the epoxy resin content in the regenerated fibers through virgin glass fibers. At the same time, the lack of "isolation bodies" interspersed between the regenerated glass fibers prevents the epoxy resin on the surface of the regenerated glass fibers from adhering to each other, resulting in a decrease in the uniformity of the initial fiber web structure. Consequently, the tensile strength and flexural strength of Comparative Example 1 are lower than those of Examples 1-3.

[0041] Comparing Examples 1-3, it was found that the glass fiber mat of Example 1 has better performance, therefore Example 1 is preferred.

[0042] Example 4 Example 4 is based on the preparation method of Example 1, except that the 15 wt% castor oil solution is replaced with a 15 wt% hydrogenated rosin alcohol solution, while the other conditions remain unchanged.

[0043] Comparative Example 2 Comparative Example 2 is based on the preparation method of Example 1, except that castor oil solution is not sprayed when material A is subjected to air-flow mesh treatment, and all other conditions remain unchanged.

[0044] The performance tests of the glass fiber mats from Examples 1, 4, and Comparative Example 2 are shown in Table 2: Performance Test Results Aging resistance The fiberglass mat was subjected to ultraviolet aging treatment at 80℃ for 72 hours. Then, the tensile strength of the fiberglass mat was tested according to the GB / T17911-2006 test standard, and the tensile strength retention rate was calculated. Tensile strength retention rate = (Tensile strength after UV aging treatment / Tensile strength before UV aging treatment) × 100%; The flexural strength of the glass fiber mat was tested according to the GB / T 1449-2005 test standard, and the flexural strength retention rate was calculated. Bending strength retention rate = Bending strength after UV aging treatment / Bending strength before UV aging treatment × 100%.

[0045] Table 2 Performance test results for Examples 1, 4 and Comparative Example 2 Referring to Table 2, comparing Example 1, Example 4 and Comparative Example 2, it can be seen that the mechanical properties and aging resistance of Example 1 and Example 4 are higher than those of Comparative Example 2. This is because no castor oil and hydrogenated rosin alcohol were added in Comparative Example 2, so an effective molecular layer could not be formed to isolate the epoxy resin particles on the surface of the recycled glass fiber and the virgin glass fiber. It is difficult to achieve uniform fiber distribution by mechanically mixing the recycled glass fiber and the virgin glass fiber alone. The local epoxy resin concentration is too high, which can easily form stress concentration points, causing cracks to be generated and propagated, thus leading to a decrease in the mechanical properties of the glass fiber mat.

[0046] Meanwhile, the non-uniform distribution of recycled glass fiber and residual epoxy resin will expose more microcracks. The presence and expansion of these microcracks will accelerate the erosion of the recycled glass fiber matrix by ultraviolet light, resulting in a significant reduction in the aging resistance of the glass fiber mat.

[0047] Comparing Examples 1 and 4, it can be seen that the tensile strength and flexural strength of Example 1 are higher than those of Example 4. This is because castor oil can interact with polyurethane molecular chains through van der Waals forces to form physical entanglement, thereby playing an internal plasticizing role and significantly improving the toughness of the glass fiber mat. At the same time, the oily groups of castor oil weaken the adhesion of epoxy resin to recycled glass fibers and reduce the surface tension of epoxy resin, making it easier for residual epoxy resin to be dispersed in the subsequent airflow web formation process, thereby improving the uniformity and continuity of the initial fiber web and enhancing the mechanical properties of the glass fiber mat.

[0048] In comparison, the overall performance of the glass fiber mat in Example 1 is better than that in Example 4, therefore Example 1 is preferred.

[0049] Examples 5-9 Example 5 is based on the preparation method of Example 1, except that the 15 wt% castor oil solution is replaced with a 15 wt% mixture of castor oil and hydrogenated rosin alcohol, with the mass ratio of castor oil to hydrogenated rosin alcohol in the mixture being 10:4, and the other conditions remain unchanged.

[0050] Examples 6-9 are based on the preparation method of Example 5, but the mass ratio of castor oil and hydrogenated rosin alcohol in the mixed solution is adjusted. The specific adjustments are shown in Table 3.

[0051] The glass fiber mats of Examples 5-9 were subjected to the above performance tests, and the test results are shown in Table 3.

[0052] Table 3. Mass ratio and performance test results of castor oil and hydrogenated rosin alcohol in Examples 1 and 5-9. Referring to Table 3, comparing Examples 1 and 5-9, it can be seen that when the dispersant includes both castor oil and hydrogenated rosin alcohol, the glass fiber mat exhibits superior mechanical properties. This is because when the dispersant includes both castor oil and hydrogenated rosin alcohol, the flexible segments of castor oil impart toughness to the glass fiber mat, while its oily groups reduce the adhesion of epoxy resin and improve dispersibility. Hydrogenated rosin alcohol molecules contain rigid ring structures and hydroxyl groups, which further disperse resin particles through electrostatic repulsion. At the same time, the rigid rings can enhance the physical support between fibers and inhibit stress concentration caused by local enrichment of epoxy resin, thereby improving the tensile strength and flexural strength of the glass fiber mat.

[0053] Comparative examples 5-9 show that both excessively low and excessively high hydrogenated rosin alcohol content can lead to a decrease in the performance of glass fiber mat. This is because when the hydrogenated rosin alcohol content is too low, it is difficult for the hydrogenated rosin alcohol to provide rigid support for the glass fiber mat; when the hydrogenated rosin alcohol content is too high, the castor oil content is relatively low, and the castor oil is difficult to improve the toughness of the glass fiber mat.

[0054] Examples 10-12 In Example 10, based on the preparation method of Example 1, 100g of polyurethane adhesive and 10g of nano titanium dioxide were mixed evenly to obtain material B. Then, material B was sprayed onto the initial fiber web, with the other conditions remaining unchanged.

[0055] Example 11 is based on the preparation method of Example 10, except that nano titanium dioxide is replaced with nano zirconium oxide, while the other conditions remain unchanged.

[0056] Example 12 is based on the preparation method of Example 10, except that nano titanium dioxide is replaced with nano silicon dioxide, while the other conditions remain unchanged.

[0057] The glass fiber mats of Examples 10-12 were subjected to the above performance tests, and the test results are shown in Table 4.

[0058] Table 4 Performance test results for Examples 1 and 10-12 Referring to Table 4, a comparison of Example 1 and Examples 10-12 shows that the mechanical properties and aging resistance of the glass fiber mats in Examples 10-12 are superior to those in Example 1. This is because nano-titanium dioxide, nano-zirconia, and nano-silica can all be tightly bonded to the polyurethane adhesive, creating more cross-linking points, thereby further consolidating the role of the polyurethane adhesive in "fixing" the residual epoxy resin and effectively enhancing the mechanical properties of the glass fiber mat.

[0059] Meanwhile, recycled glass fibers and residual epoxy resins often have defects such as microcracks and pores on their surface due to pretreatment such as crushing. The addition of nano-titanium dioxide, nano-zirconia, or nano-silica can be embedded into these defects through physical filling, increasing the contact area between polyurethane adhesive and recycled glass fibers, further enhancing interfacial bonding, effectively inhibiting crack propagation, and improving the aging resistance of glass fiber mat.

[0060] Comparing Examples 10-12, it can be seen that the aging resistance of Example 10 is higher than that of Examples 11-12. This is because nano-titanium dioxide has extremely strong absorption and scattering ability for ultraviolet light, which can effectively inhibit the oxidation chain scission reaction of polyurethane adhesive caused by ultraviolet light irradiation, thereby delaying the aging of glass fiber mat. Therefore, Example 10 is preferred.

[0061] Examples 13-17 Example 13 is based on the preparation method of Example 10, except that castor oil is replaced with hydrogenated rosin alcohol, while the other conditions remain unchanged.

[0062] Examples 14-17 are based on the preparation method of Example 13, but the amount of nano-titanium dioxide added is adjusted. The specific adjustments are shown in Table 5.

[0063] The performance tests of Examples 4 and 13-17 were performed as described above, and the test results are shown in Table 5.

[0064] Table 5. Mass ratio and performance test results of hydrogenated rosin alcohol and nano-titanium dioxide in Examples 4, 10, and 13-17. Referring to Table 5, a comparison of Examples 4, 10, and 13-17 shows that the bending strength of Examples 13-17 is higher than that of Example 4 but lower than that of Example 10. This is because the effect of hydrogenated rosin alcohol (Examples 13-17) on improving the toughness of glass fiber mat is not as good as that of castor oil (Example 10). Furthermore, nano-titanium dioxide was added to Examples 13-17, and its spherical or near-spherical structure can play a "ball effect" in the fiber network. When the material is subjected to external force, the rolling of particles can alleviate stress concentration. Therefore, the toughness of the glass fiber mat in Example 13 is better than that in Example 4.

[0065] Comparing Examples 10 and 13-17, it can be seen that the glass fiber mat of Examples 13-17 has better UV aging resistance than that of Example 10. This is because nano-titanium dioxide may release free radicals when it absorbs ultraviolet light, which attack the polyurethane molecular chain and cause degradation. The rigid tricyclic structure of hydrogenated rosin alcohol molecules has multiple active sites, which can specifically react with free radicals, quench the activity of free radicals, and inhibit the occurrence of such degradation.

[0066] Comparative examples 13-17 show that both excessively low and excessively high amounts of nano-titanium dioxide can lead to a decrease in the aging resistance of glass fiber mat. This is because when the content of nano-titanium dioxide is too low, its shielding effect against ultraviolet rays is unclear; while when the content of nano-titanium dioxide is too high, excessive nano-titanium dioxide may release more free radicals, which will weaken the quenching ability of hydrogenated rosin alcohol on free radicals, thus reducing the aging resistance of glass fiber mat.

[0067] Application Examples The glass fiber mats prepared in Examples 1-17 of this application can all be used in the preparation of glass fiber mat composite boards. This application example only uses the glass fiber mat prepared in Example 1 as an example for illustration.

[0068] See Figure 1 A glass fiber mat composite board includes a first polyurethane layer 1, a glass fiber mat layer 2, and a second polyurethane layer 3, wherein the glass fiber mat layer 2 is located between the first polyurethane layer 1 and the second polyurethane layer 3. Its preparation method includes the following steps: Polyurethane, the glass fiber mat prepared in Example 1, and polyurethane are sequentially stacked and hot-pressed to obtain a glass fiber mat composite board. The hot pressing temperature is 140℃ and the pressure is 0.5MPa.

[0069] Performance testing The fiberglass mat composite board used in this application was subjected to the following performance tests: According to the GB / T 8808 standard, the 180° peel strength of the glass fiber mat composite board used in the application example was 86.54 N / cm.

[0070] The glass fiber mat composite board in the application example has high peel strength. This is because the glass fiber mat layer is prepared using polyurethane adhesive as a structural adhesive, which has good interfacial compatibility with both the first and second polyurethane layers, making the interlayer bonding of the composite board strong and not easy to peel off.

[0071] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing glass fiber mat, characterized in that, Includes the following steps: Pretreatment: Waste glass fiber products are crushed and then air-separated to obtain recycled glass fiber; Deposition into a web: The recycled glass fiber and the virgin glass fiber are mixed evenly to obtain material A. Then, material A is spread into a web by airflow while a dispersant solution is sprayed, and the initial fiber web is deposited. Fabrication: Polyurethane adhesive is sprayed onto the initial fiber web and heated to cure to obtain glass fiber mat; The mass ratio of the recycled glass fiber to the virgin glass fiber is 7:(2-3); The dispersant in the dispersant solution is at least one of castor oil and hydrogenated rosin alcohol.

2. The method for preparing glass fiber mat according to claim 1, characterized in that: The dispersant is castor oil.

3. The method for preparing glass fiber mat according to claim 1, characterized in that: The dispersant is a mixture of castor oil and hydrogenated rosin alcohol.

4. The method for preparing glass fiber mat according to claim 3, characterized in that: The mass ratio of castor oil to hydrogenated rosin alcohol is 10:(3-5).

5. The method for preparing glass fiber mat according to claim 1, characterized in that: In the felt-making process, the polyurethane adhesive and nanofiller are first uniformly mixed to obtain material B. Then, material B is sprayed onto the initial fiber web and heated and cured to obtain glass fiber felt.

6. The method for preparing glass fiber mat according to claim 5, characterized in that: The nanofiller includes at least one of nano-titanium dioxide and nano-zirconia.

7. The method for preparing glass fiber mat according to claim 6, characterized in that: The nanofiller is nano-titanium dioxide.

8. The method for preparing glass fiber mat according to claim 7, characterized in that: The dispersant is hydrogenated rosin alcohol, and the mass ratio of hydrogenated rosin alcohol to nano-titanium dioxide is 10:(3-4).

9. A glass fiber mat composite board, characterized in that: It includes a first polyurethane layer, a glass fiber mat layer, and a second polyurethane layer, wherein the glass fiber mat layer is located between the first polyurethane layer and the second polyurethane layer; The glass fiber mat layer is prepared by the method for preparing glass fiber mat according to any one of claims 1-8.

10. The method for preparing the glass fiber mat composite board according to claim 9, characterized in that, Includes the following steps: Polyurethane, glass fiber mat, and polyurethane are sequentially stacked and hot-pressed to obtain the glass fiber mat composite board.

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