A method for high-value recycling of unsaturated polyester fiberglass waste

Abstract

The present invention belongs to the technical field of recycling and reusing unsaturated polyester fiberglass (FRP) waste and preparing regenerated unsaturated polyester fiberglass. It relates to a method for the high-value recycling of unsaturated polyester fiberglass waste. The method comprises pre-treating the unsaturated polyester fiberglass waste and then grinding it in a millstone-shaped solid-phase force chemical reactor to obtain an ultrafine powder. The ultrafine powder is then mixed with a viscosity reducer or a small molecule monomer modifier and then co-milled again. The resulting fiberglass reinforcing filler with viscosity reduction functionality is used as a raw material and added to an unsaturated polyester resin paste according to conventional processes to produce regenerated unsaturated polyester fiberglass. The fiberglass reinforcing filler with viscosity reduction functionality is used to replace conventional viscosity reducers and part of the glass fiber to produce regenerated unsaturated polyester fiberglass with qualified performance, providing a new approach for the high-value recycling of unsaturated polyester fiberglass waste.

Description

Technical Field

[0001] The present invention belongs to the technical field of recycling and reusing unsaturated polyester fiberglass waste and preparing regenerated unsaturated polyester fiberglass, and relates to a method for high-value recycling of unsaturated polyester fiberglass waste. Specifically, the present invention relates to utilizing the waste generated in the production process of unsaturated polyester fiberglass as reinforcing filler and viscosity reducer after treatment, and using the waste to replace conventional viscosity reducer and part of glass fiber to prepare regenerated unsaturated polyester fiberglass with qualified performance. In particular, the present invention is directed to utilizing an industrial grinding disc-shaped solid phase force chemical reactor disclosed in Chinese invention patent CN114534660B to participate in the treatment of the waste. Background Art

[0002] Unsaturated polyester fiberglass (FRP) is a high-performance composite material based on unsaturated polyester resin and reinforced with glass fiber and its products (glass cloth, tape, felt, yarn, etc.). It features excellent corrosion resistance, high strength, low thermal expansion coefficient, and ease of processing. It is widely used in various sectors of the national economy, including petroleum, chemicals, pesticides, pharmaceuticals, dyes, electroplating, electrolysis, smelting, and light industry. Unsaturated polyester resin paste, the primary raw material for FRP, is a viscous liquid material based on unsaturated polyester resin and formulated with additives such as vinyl monomers (such as styrene), accelerators, and thixotropic agents. In the conventional FRP molding process, the unsaturated polyester resin paste is typically impregnated into the surface and interior of the glass fiber mat, then cured and molded to produce the FRP.

[0003] In the modern unsaturated polyester fiberglass molding production process, a large amount of waste materials, mainly scraps, are usually generated, accounting for about 5% of the total product mass. However, because the unsaturated polyester resin in this type of waste has been solidified, it has a three-dimensional cross-linked network structure and is insoluble and infusible. It is generally recognized in the existing technology that it is difficult to directly recycle and reuse waste materials.

[0004] Currently, the recycling of this type of unsaturated polyester fiberglass waste is mostly based on physical recycling techniques, such as mechanical crushing to produce fiberglass powder, which is then used as filler in road or building materials. This method is relatively mature, but the value of the recycled products is quite low. However, in practice, this type of unsaturated polyester fiberglass waste is still mostly disposed of in landfills. In recent years, some researchers have also explored new recycling strategies, using fiberglass waste as raw material to produce recycled fiberglass products, with some success.

[0005] For example, the inventor of the present invention previously applied for an invention patent "Glass fiber reinforced plastic recycled product using discarded wind turbine blades as raw materials and its preparation method" (CN118063854A), which disclosed a glass fiber reinforced plastic recycled product using discarded wind turbine blades as raw materials and its preparation method. It first provides a method for preparing highly compatible and reactive fillers using discarded wind turbine blades, wherein the discarded wind turbine blade products are added to a grinding disc-type solid phase force chemical reactor after pretreatment and ground and pulverized to obtain ultrafine wind turbine blade powder, and then the ultrafine wind turbine blade powder is mixed with an activator and co-ground to obtain a highly compatible and reactive filler; and then the highly compatible and reactive filler is used as part of the raw material to prepare the glass fiber reinforced plastic recycled product.

[0006] However, during the implementation and transformation test of the above-mentioned patented technology, it was found that when the patented technology was substituted into the actual production process, because it mainly used reactive activators to improve the compatibility of wind turbine blade powder and epoxy resin, and was limited by laboratory conditions, it did not pay attention to the fact that adding this highly compatible and reactive filler to the thermosetting resin system would lead to a sharp increase in viscosity. Industrial production equipment based on conventional processes could not produce normally, and a large amount of viscosity reducers had to be added to reduce the viscosity, which posed a serious challenge to the existing FRP product production process and cost. Therefore, how to develop a recycling method that can be effectively implemented is very necessary to achieve the industrial recycling of unsaturated polyester FRP waste. Summary of the Invention

[0007] In order to solve the above-mentioned problems in the prior art, the present invention provides a method for high-value recycling of unsaturated polyester fiberglass waste. It is found that after the unsaturated polyester fiberglass waste is treated with a conventional viscosity reducer or a small molecule monomer modifier, including co-grinding, it can be directly used as a reinforcing filler and viscosity reducer. It is used to replace the conventional viscosity reducer and part of the glass fiber to prepare regenerated unsaturated polyester fiberglass with qualified performance, which provides a new way for the high-value recycling of unsaturated polyester fiberglass waste.

[0008] In order to achieve the above-mentioned objectives, the present invention is implemented by adopting a technical solution consisting of the following technical measures.

[0009] The present invention provides a method for high-value recycling of unsaturated polyester fiberglass waste, which mainly comprises the following steps:

[0010] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of not more than 10 mm;

[0011] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 2-5 MPa, introduction of 10-25 °C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 2-5 times, and grinding disc speed of 40-50 rpm;

[0012] (3) The ultrafine FRP powder obtained in step (2) is uniformly mixed with a viscosity reducer or a small molecule monomer modifier to form a mixture, and then added to a grinding disc-shaped solid phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, the FRP reinforcing filler with viscosity reduction functionality is collected; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 2-3 MPa, introduction of 10-25 ° C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 2-3 times, and grinding disc speed of 40-50 rpm;

[0013] Wherein, the small molecule monomer modifier is any one of acrylic acid, triethylene glycol divinyl ether, methacrylate, and methyl acrylate;

[0014] The mass ratio of the glass fiber reinforced plastic ultrafine powder to the viscosity reducer / small molecule monomer modifier in the mixture is 9: (0.5-1.5);

[0015] (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0016] 100 parts of unsaturated polyester resin paste,

[0017] 5~8 parts of glass fiber reinforced filler,

[0018] 15-25 parts of glass fiber;

[0019] The obtained mixed matrix is prepared according to a conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic.

[0020] In this article, the pretreatment including cleaning described in step (1) is mainly to clean the surface of the unsaturated polyester fiberglass waste and remove impurities. Those skilled in the art can carry out specific treatment according to the actual conditions of the unsaturated polyester fiberglass waste to be recycled and utilized according to the existing technology.

[0021] It should be noted that the unsaturated polyester fiberglass waste material in step (1) is usually scraps generated during the unsaturated polyester fiberglass molding production process, and the unsaturated polyester resin in this type of waste material has been solidified.

[0022] In this article, the FRP crushed material to an average particle size of not more than 10 mm in step (1) can be crushed to a size that is convenient for being placed in a grinding disc-shaped solid phase force chemical reactor for grinding. The crushing method can be conventional tearing or crushing, for example, by using existing conventional tearing or crushing equipment such as single-axis and double-axis tearing machines, jaw crushers, etc.

[0023] The millstone-shaped solid-phase force chemical reactor in steps (2) and (3) is the industrial millstone-shaped solid-phase force chemical reactor disclosed in the prior invention patent CN114534660B of the applicant of the present invention.

[0024] It should be noted that this industrial millstone-shaped solid-phase force chemical reactor is based on the principle of the force chemical reactor disclosed in the previously authorized patent ZL95111258.9, and is the final improved industrial equipment. It is significantly different from the structure of the laboratory prototype when ZL95111258.9 was applied for. A new millstone structure is designed for industrial high-efficiency force chemical grinding treatment. The previous vertical setting of the millstone is improved to a horizontal setting, and the size of the millstone is greatly increased. Based on the horizontal setting and large size of the millstone, the relevant fixed millstone components and hydraulic lifting system are innovatively designed, which greatly improves its three-dimensional shear force.

[0025] Generally, the actual operation of the above-mentioned cyclic milling process is to grind the material through a millstone-shaped solid phase force chemical reactor, collect the product at the discharge end and place it again in a millstone-shaped solid phase force chemical reactor for grinding treatment. The above process is regarded as one cyclic milling.

[0026] In this article, in steps (2) and (3), a circulating cooling liquid at 10-25°C is introduced to control the temperature of the grinding disc surface, and the cooling liquid is water, ethylene glycol or glycerol.

[0027] Based on the experimental conclusions of their prior patent application, "Fiberglass Recycled Products Using Waste Wind Turbine Blades as Raw Materials and Preparation Method Thereof" (CN118063854A), the inventors discovered that when this patented technology was applied to actual production processes, when preparing fiberglass recycled products using epoxy resin as a matrix according to the methods described in the patent's examples, the addition of the highly compatible and reactive filler to the epoxy resin led to a sharp increase in viscosity. This was a defect that had not been addressed during laboratory sample production in the prior patent application. Furthermore, when milled ultrafine wind turbine blade powder or ultrafine fiberglass powder was directly added to the epoxy resin, a significant increase in viscosity was also observed.

[0028] On this basis, when unsaturated polyester is selected as the matrix, the above-mentioned viscosity increase problem also exists. Moreover, due to the obvious differences between the unsaturated polyester FRP production system and the epoxy resin FRP production system, especially in the unsaturated polyester FRP production system, the viscosity problem is magnified and cannot be produced normally for industrial production equipment based on conventional processes. For example, in the molding process, the optimal molding viscosity is about 2.0×10 4 cP (Plastics Industry Handbook: Unsaturated Polyester Resins, Chemical Industry Press, 2001).

[0029] If the ground FRP ultrafine powder (obtained by directly grinding unsaturated polyester FRP waste) or the highly compatible and reactive filler obtained in accordance with the technical solution of the prior invention patent application (obtained by grinding unsaturated polyester FRP waste and then mixing it with an activator and then co-grinding) is directly added to the unsaturated polyester resin paste, it is considered after evaluation that an additional viscosity reducer (about 1-5 wt%, depending on the viscosity reducing effect of different viscosity reducers) needs to be added to reduce the viscosity of the mixed matrix (the FRP product base material composed of the unsaturated polyester resin paste, FRP ultrafine powder / highly compatible and reactive filler and glass fiber) to 3.0×10 4 Only when the viscosity is below cP can conventional industrial production equipment be used for large-scale and batch production, posing a severe challenge to the existing production process and cost of FRP products. Furthermore, as the amount of viscosity reducer added increases, especially when low-cost viscosity reducers are insufficient due to the need for large amounts, the mechanical properties of the resulting FRP products will significantly deteriorate.

[0030] Based on these facts, while attempting to shift their thinking, the inventors unexpectedly discovered that by co-grinding a viscosity reducer or small-molecule monomer modifier with ultrafine FRP powder (obtained by grinding and pulverizing unsaturated polyester FRP waste), the viscosity of the blended product with unsaturated polyester can be significantly reduced, with relatively small amounts or no additional viscosity reducer added. This research achievement not only eliminates the need for the addition of viscosity reducers in conventional unsaturated polyester FRP production processes, but also reduces actual production costs. This allows the method of the present invention to be seamlessly integrated with existing unsaturated polyester FRP production processes, resulting in the production of regenerated unsaturated polyester FRP with acceptable performance. This provides a novel approach for the high-value recycling of unsaturated polyester FRP waste.

[0031] It should be emphasized that the inventor's prior invention patent application "Fiberglass Recycled Products Using Abandoned Wind Turbine Blades as Raw Materials and Their Preparation Method" (CN118063854A) discloses the co-grinding mechanochemical reaction of activator diethylenetriamine or ethylene glycol with ultrafine wind turbine blade powder. It mainly utilizes the mechanochemical reaction of polyamine or alcohol with epoxy resin to generate modified wind turbine blade powder containing amino groups and hydroxyl groups. The surface active groups of the powder have high polarity and have strong intermolecular interactions with the epoxy groups and hydroxyl groups in the epoxy resin, thereby improving compatibility. However, there is no viscosity reduction effect, and there are no similar public reports.

[0032] In this article, the viscosity reducer in step (3) is a conventional viscosity reducer used in the industry, such as BYK-W9010, BYK-W 996, Walker VOK-9010A, and DP-8012 of Chinese fir new material.

[0033] It should be noted that BYK-W 9010 was used as a viscosity reducer in the following examples. BYK-W 9010 is currently recognized as a viscosity reducer with excellent viscosity reduction performance but relatively high cost. It is currently the optimal choice for reducing the amount of viscosity reducer based on conventional thinking. If replaced with a low-cost viscosity reducer commonly used in industry, generally speaking, it may require 2 to 3 times the amount of BYK-W 9010 to achieve the same viscosity reduction effect.

[0034] It should be noted that the small molecule monomer modifier in step (3) is any one of acrylic acid, triethylene glycol divinyl ether, methacrylate, and methyl acrylate. In actual comparative experiments, it was found that, based on the same addition amount, the viscosity reduction effects of the above small molecule monomer modifiers after co-grinding with the ultrafine fiberglass reinforced plastic powder were significantly different. Based on the experimental results, acrylic acid is further preferred as the small molecule monomer modifier.

[0035] In this article, the unsaturated polyester resin paste described in step (4) is a common industry term in the production process of unsaturated polyester fiberglass. It is a viscous liquid material based on unsaturated polyester resin and prepared by adding vinyl monomers (such as styrene), shrink agents, flame retardants, initiators, promoters, thixotropic agents and other additives. It should be noted that it is not a single unsaturated resin.

[0036] In this article, the glass fiber described in step (4) is the glass fiber reinforcement material conventionally selected in the preparation process of FRP. Those skilled in the art can select appropriate glass fibers, such as chopped glass fibers, glass fiber products (glass cloth, tape, felt, yarn, etc.), etc., according to their existing preparation process of FRP or the records in the existing technical literature.

[0037] In this article, the obtained mixed matrix described in step (4) is prepared according to the conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic. Those skilled in the art can know its specific process flow and operation based on the existing preparation process of glass fiber reinforced plastic or the records in the existing technical literature.

[0038] In order to better illustrate the present invention and provide a technical solution for reference, the mixed matrix obtained in step (4) is prepared according to a conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic. Specifically, the mixed matrix obtained is leveled on a release cloth, and a release cloth is laid on the upper surface thereof. The mixed matrix is aged at a temperature of 30-40°C in a light-proof environment for at least 24 hours, and then the release cloth is removed. The recycled glass fiber reinforced plastic product is obtained by a compression molding method.

[0039] In this article, the uniform mixing, leveling, curing, and molding all follow conventional principles in chemical processes, and those skilled in the art can perform specific operations based on common knowledge.

[0040] The present invention has the following beneficial effects:

[0041] (1) The present invention provides a method for high-value recycling of unsaturated polyester fiberglass waste. The method grafts a viscosity reducer or a small molecule monomer modifier onto the surface of fiberglass ultrafine powder through the strong three-dimensional shear force of a grinding disc-shaped solid phase chemical reactor. Compared with directly adding the viscosity reducer or the small molecule monomer modifier to the mixed matrix, the viscosity reduction effect is more significant, and the viscosity can be greatly reduced or no additional viscosity reducer is required.

[0042] (2) The technical solution of the present invention uses unsaturated polyester fiberglass waste scraps as raw materials, which can achieve the same-level recycling in unsaturated polyester fiberglass products. It is different from the existing physical recycling technology that uses unsaturated polyester fiberglass powder in road asphalt or concrete building materials, and has higher economic value.

[0043] (3) The technical solution of the present invention can be directly combined with the current unsaturated polyester fiberglass preparation process without any obstacles to prepare recycled unsaturated polyester fiberglass with qualified performance. At the same time, it is simple to operate, has low recycling cost, is easy to mass produce, and no waste is generated during the recycling process, and there is no secondary pollution, which has a clear industrialization prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 These are actual photos of the unsaturated polyester fiberglass waste material (left) used in step (1) of Example 1 of the present invention and the fiberglass reinforced filler with viscosity-reducing functionality obtained in step (3) (right).

[0045] Figure 2This is a photo of the unsaturated polyester resin paste used in step (4) of Example 1 of the present invention. DETAILED DESCRIPTION

[0046] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the claims of the invention. Those skilled in the art can refer to the contents of this article and appropriately improve the process parameters for implementation. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention. Although it is believed that those of ordinary skill in the art fully understand the following terms, the following definitions are still stated to help illustrate the subject matter disclosed by the present invention.

[0047] The present invention provides a method for high-value recycling of unsaturated polyester fiberglass waste, which mainly comprises the following steps:

[0048] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of not more than 10 mm;

[0049] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 2-5 MPa, introduction of 10-25 °C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 2-5 times, and grinding disc speed of 40-50 rpm;

[0050] (3) The ultrafine FRP powder obtained in step (2) is uniformly mixed with a viscosity reducer or a small molecule monomer modifier to form a mixture, and then added to a grinding disc-shaped solid phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, the FRP reinforcing filler with viscosity reduction functionality is collected; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 2-3 MPa, introduction of 10-25 ° C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 2-3 times, and grinding disc speed of 40-50 rpm;

[0051] Wherein, the small molecule monomer modifier is any one of acrylic acid, triethylene glycol divinyl ether, methacrylate, and methyl acrylate;

[0052] The mass ratio of the glass fiber reinforced plastic ultrafine powder to the viscosity reducer / small molecule monomer modifier in the mixture is 9: (0.5-1.5);

[0053] (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0054] 100 parts of unsaturated polyester resin paste,

[0055] 5~8 parts of glass fiber reinforced filler,

[0056] 15-25 parts of glass fiber;

[0057] The obtained mixed matrix is prepared according to a conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic.

[0058] In this article, the pretreatment including cleaning described in step (1) is mainly to clean the surface of the unsaturated polyester fiberglass waste and remove impurities. Those skilled in the art can carry out specific treatment according to the actual conditions of the unsaturated polyester fiberglass waste to be recycled and utilized according to the existing technology.

[0059] It should be noted that the unsaturated polyester fiberglass waste material in step (1) is usually scraps generated during the unsaturated polyester fiberglass molding production process, and the unsaturated polyester resin in this type of waste material has been solidified.

[0060] In this article, the fiberglass crushed material that is crushed to an average particle size of not more than 10 mm in step (1) can be crushed to a size that is convenient for being placed in a grinding disc-shaped solid phase force chemical reactor for grinding. In one embodiment, the crushing method can be conventional tearing or crushing. For example, it is processed by existing conventional tearing or crushing equipment such as single-axis and double-axis tearing machines, jaw crushers, etc.

[0061] The millstone-shaped solid-phase force chemical reactor in steps (2) and (3) is the industrial millstone-shaped solid-phase force chemical reactor disclosed in the prior invention patent CN114534660B of the applicant of the present invention.

[0062] It should be noted that this industrial millstone-shaped solid-phase force chemical reactor is based on the principle of the force chemical reactor disclosed in the previously authorized patent ZL95111258.9, and is the final improved industrial equipment. It is significantly different from the structure of the laboratory prototype when ZL95111258.9 was applied for. A new millstone structure is designed for industrial high-efficiency force chemical grinding treatment. The previous vertical setting of the millstone is improved to a horizontal setting, and the size of the millstone is greatly increased. Based on the horizontal setting and large size of the millstone, the relevant fixed millstone components and hydraulic lifting system are innovatively designed, which greatly improves its three-dimensional shear force.

[0063] Generally, the actual operation of the above-mentioned cyclic milling process is to grind the material through a millstone-shaped solid phase force chemical reactor, collect the product at the discharge end and place it again in a millstone-shaped solid phase force chemical reactor for grinding treatment. The above process is regarded as one cyclic milling.

[0064] In this article, in steps (2) and (3), a circulating cooling liquid at 10-25°C is introduced to control the temperature of the grinding disc surface. In one embodiment, the cooling liquid is water, ethylene glycol or glycerol.

[0065] Based on the experimental conclusions of their prior patent application, "Fiberglass Recycled Products Using Waste Wind Turbine Blades as Raw Materials and Preparation Method Thereof" (CN118063854A), the inventors discovered that when this patented technology was applied to actual production processes, when preparing fiberglass recycled products using epoxy resin as a matrix according to the methods described in the patent's examples, the addition of the highly compatible and reactive filler to the epoxy resin led to a sharp increase in viscosity. This was a defect that had not been addressed during laboratory sample production in the prior patent application. Furthermore, when milled ultrafine wind turbine blade powder or ultrafine fiberglass powder was directly added to the epoxy resin, a significant increase in viscosity was also observed.

[0066] On this basis, when unsaturated polyester is selected as the matrix, the above-mentioned viscosity increase problem also exists. Moreover, due to the obvious differences between the unsaturated polyester FRP production system and the epoxy resin FRP production system, especially in the unsaturated polyester FRP production system, the viscosity problem is magnified and cannot be produced normally for industrial production equipment based on conventional processes. For example, in the molding process, the optimal molding viscosity is about 2.0×10 4 cP (Plastics Industry Handbook: Unsaturated Polyester Resins, Chemical Industry Press, 2001).

[0067] If the ground FRP ultrafine powder (obtained by directly grinding unsaturated polyester FRP waste) or the highly compatible and reactive filler obtained in accordance with the technical solution of the prior invention patent application (obtained by grinding unsaturated polyester FRP waste and then mixing it with an activator and then co-grinding) is directly added to the unsaturated polyester resin paste, it is considered after evaluation that an additional viscosity reducer (about 1-5wt%, depending on the viscosity reducing effect of different viscosity reducers) needs to be added to reduce the viscosity of the mixed matrix (the FRP product base material composed of the unsaturated polyester resin paste, FRP ultrafine powder / highly compatible and reactive filler and glass fiber) to 3.0×10 4 Only when the viscosity is below cP can conventional industrial production equipment be used for large-scale and batch production, posing a severe challenge to the existing production process and cost of FRP products. Furthermore, as the amount of viscosity reducer added increases, especially when low-cost viscosity reducers are insufficient due to the need for large amounts, the mechanical properties of the resulting FRP products will significantly deteriorate.

[0068] Based on these facts, while attempting to shift their thinking, the inventors unexpectedly discovered that by co-grinding a viscosity reducer or small-molecule monomer modifier with ultrafine FRP powder (obtained by grinding and pulverizing unsaturated polyester FRP waste), the viscosity of the blended product with unsaturated polyester can be significantly reduced, with relatively small amounts or no additional viscosity reducer added. This research achievement not only eliminates the need for the addition of viscosity reducers in conventional unsaturated polyester FRP production processes, but also reduces actual production costs. This allows the method of the present invention to be seamlessly integrated with existing unsaturated polyester FRP production processes, resulting in the production of regenerated unsaturated polyester FRP with acceptable performance. This provides a novel approach for the high-value recycling of unsaturated polyester FRP waste.

[0069] It should be emphasized that the inventor's prior invention patent application "Fiberglass Recycled Products Using Abandoned Wind Turbine Blades as Raw Materials and Their Preparation Method" (CN118063854A) discloses the co-grinding mechanochemical reaction of activator diethylenetriamine or ethylene glycol with ultrafine wind turbine blade powder. It mainly utilizes the mechanochemical reaction of polyamine or alcohol with epoxy resin to generate modified wind turbine blade powder containing amino groups and hydroxyl groups. The surface active groups of the powder have high polarity and have strong intermolecular interactions with the epoxy groups and hydroxyl groups in the epoxy resin, thereby improving compatibility. However, there is no viscosity reduction effect, and there are no similar public reports.

[0070] In this article, the viscosity reducer in step (3) is a conventional viscosity reducer used in the industry in this field. In one embodiment, for example, any one of BYK-W 9010, BYK-W 996, Walker VOK-9010A, and Chinese fir new material DP-8012 is selected.

[0071] It should be noted that BYK-W 9010 was used as a viscosity reducer in the following examples. BYK-W 9010 is currently recognized as a viscosity reducer with excellent viscosity reduction performance but relatively high cost. It is currently the optimal choice for reducing the amount of viscosity reducer based on conventional thinking. If replaced with a low-cost viscosity reducer commonly used in industry, generally speaking, it may require 2 to 3 times the amount of BYK-W 9010 to achieve the same viscosity reduction effect.

[0072] It should be noted that the small molecule monomer modifier in step (3) is any one of acrylic acid, triethylene glycol divinyl ether, methacrylate, and methyl acrylate. In actual comparative experiments, it was found that, based on the same addition amount, the viscosity reduction effects of the above small molecule monomer modifiers after co-grinding with ultrafine fiberglass reinforced plastic powder were significantly different. Based on the experimental results, in one preferred embodiment, it is further preferred that the small molecule monomer modifier is acrylic acid.

[0073] In one embodiment, the mass ratio of the FRP ultrafine powder to the viscosity reducer / small molecule monomer modifier in the mixture in step (3) is 9:(0.5~1.5), for example, 9:0.5, 9:0.6, 9:0.7, 9:0.8, 9:0.9, 9:1, 9:1.1, 9:1.2, 9:1.3, 9:1.4, 9:1.5 or any range or point value therebetween.

[0074] In this article, the unsaturated polyester resin paste described in step (4) is a common industry term in the production process of unsaturated polyester fiberglass. It is a viscous liquid material based on unsaturated polyester resin and prepared by adding vinyl monomers (such as styrene), shrink agents, flame retardants, initiators, promoters, thixotropic agents and other additives. It should be noted that it is not a single unsaturated resin.

[0075] In this article, the glass fiber described in step (4) is a glass fiber reinforcement material conventionally selected in the preparation process of FRP. Those skilled in the art can select appropriate glass fiber according to their existing preparation process of FRP or the records in the existing technical literature. In one embodiment, for example, it includes any one of chopped glass fiber, glass cloth, glass tape, glass mat, and glass yarn.

[0076] In one embodiment, the fiberglass reinforced filler in step (4) is 5 to 8 parts, for example, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts or any range or point value therebetween.

[0077] In one embodiment, the glass fiber in step (4) is 15 to 25 parts, for example, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts or any range or point value therebetween.

[0078] In this article, the obtained mixed matrix described in step (4) is prepared according to the conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic. Those skilled in the art can know its specific process flow and operation based on the existing preparation process of glass fiber reinforced plastic or the records in the existing technical literature.

[0079] In order to better illustrate the present invention and provide an embodiment for reference, the obtained mixed matrix described in step (4) is prepared according to the conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic. Specifically, the obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on the upper surface thereof. It is matured at a temperature of 30-40°C in a light-proof environment for at least 24 hours, and then the release cloth is removed. The glass fiber reinforced plastic recycled product is prepared by a molding method.

[0080] In this article, the uniform mixing, leveling, curing, and molding all follow conventional principles in chemical processes, and those skilled in the art can perform specific operations based on common knowledge.

[0081] The present invention will be further explained in detail below with reference to the examples. However, it will be appreciated by those skilled in the art that these examples are provided for illustrative purposes only and are not intended to limit the present invention.

[0082] Example

[0083] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if no specific conditions are indicated, the conditions are carried out according to normal conditions or manufacturer recommendations. The reagents used or the instruments that are not indicated by the manufacturer are conventional products that can be obtained commercially. The application should not be construed as being limited to the specific examples described.

[0084] 1. Raw materials

[0085] Unsaturated polyester fiberglass waste comes from the scraps generated during the production and processing of fiberglass and is provided by Sichuan Difu Electrical Technology Co., Ltd.

[0086] Acrylic acid, triethylene glycol divinyl ether, methacrylate, etc. were provided by Chengdu Kelong Chemical Co., Ltd.;

[0087] BYK-W 9010 was purchased from BYK Chemicals;

[0088] Other raw materials such as chopped glass fiber are provided by Sichuan Difu Electrical Technology Co., Ltd.

[0089] 2. Test methods

[0090] The viscosity of the mixed matrix in the examples and comparative examples of the present invention was measured according to ISO / TS 23927:2024.

[0091] The tensile properties were tested in accordance with GB / T 2567-2008.

[0092] Example 1

[0093] The present embodiment provides a method for high-value recycling of unsaturated polyester fiberglass waste, which mainly includes the following steps:

[0094] (1) If Figure 1 (Left) Unsaturated polyester fiberglass waste is pre-processed, including washing, and then crushed to a fiberglass crusher with an average particle size of approximately 6 mm.

[0095] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0096] (3) The ultrafine FRP powder obtained in step (2) is mixed evenly with acrylic acid as a mixture, and then added into a grinding disc-shaped solid phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, the FRP reinforcing filler with viscosity-reducing functionality is collected and obtained. The actual picture of the FRP reinforcing filler with viscosity-reducing functionality is as shown in FIG. Figure 1 (right); the process parameters of the millstone-shaped solid-phase force chemical reactor are: grinding pressure of 2 MPa, 15°C circulating cooling liquid to control the temperature of the millstone surface, 2 cycles of grinding, and a millstone speed of 50 rpm;

[0097] The mass ratio of glass fiber reinforced plastic ultrafine powder to acrylic acid in the mixture is 9:1;

[0098] (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0099] 100 parts of unsaturated polyester resin paste,

[0100] 5 parts of glass fiber reinforced filler,

[0101] 25 parts of chopped glass fiber;

[0102] Among them, the unsaturated polyester resin paste used is as follows Figure 2 As shown;

[0103] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0104] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0105] Example 2

[0106] The present embodiment provides a method for high-value recycling of unsaturated polyester fiberglass waste, which mainly includes the following steps:

[0107] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0108] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0109] (3) The ultrafine FRP powder obtained in step (2) is uniformly mixed with triethylene glycol divinyl ether to form a mixture, and the mixture is added to a millstone-shaped solid phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, the FRP reinforced filler with viscosity reduction functionality is collected; wherein the process parameters of the millstone-shaped solid phase force chemical reactor are: grinding pressure of 2 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the millstone surface, cyclic grinding for 2 times, and a millstone speed of 50 rpm;

[0110] The mass ratio of the glass fiber reinforced plastic ultrafine powder to triethylene glycol divinyl ether in the mixture is 9:1;

[0111] (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0112] 100 parts of unsaturated polyester resin paste,

[0113] 5 parts of glass fiber reinforced filler,

[0114] 25 parts of chopped glass fiber;

[0115] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0116] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0117] Example 3

[0118] The present embodiment provides a method for high-value recycling of unsaturated polyester fiberglass waste, which mainly includes the following steps:

[0119] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0120] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0121] (3) The ultrafine FRP powder obtained in step (2) is uniformly mixed with methacrylate to form a mixture, and the mixture is added to a millstone-shaped solid phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, the FRP reinforced filler with viscosity reduction functionality is collected; wherein the process parameters of the millstone-shaped solid phase force chemical reactor are: grinding pressure of 2 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the millstone surface, cyclic grinding for 2 times, and a millstone speed of 50 rpm;

[0122] The mass ratio of the glass fiber reinforced plastic ultrafine powder to methacrylate in the mixture is 9:1;

[0123] (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0124] 100 parts of unsaturated polyester resin paste,

[0125] 5 parts of glass fiber reinforced filler,

[0126] 25 parts of chopped glass fiber;

[0127] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0128] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0129] Example 4

[0130] The present embodiment provides a method for high-value recycling of unsaturated polyester fiberglass waste, which mainly includes the following steps:

[0131] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0132] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0133] (3) The ultrafine FRP powder obtained in step (2) is evenly mixed with BYK-W 9010 as a mixture, and is added to a millstone-shaped solid phase force chemical reactor again for co-grinding and pulverization. After the grinding is completed, the FRP reinforced filler with viscosity reduction functionality is collected; wherein the process parameters of the millstone-shaped solid phase force chemical reactor are: grinding pressure of 2 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the millstone surface, cyclic grinding twice, and a millstone speed of 50 rpm;

[0134] The mass ratio of the glass fiber reinforced plastic ultrafine powder to BYK-W 9010 in the mixture is 9:1;

[0135] (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0136] 100 parts of unsaturated polyester resin paste,

[0137] 5 parts of glass fiber reinforced filler,

[0138] 25 parts of chopped glass fiber;

[0139] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0140] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0141] Example 5

[0142] The present embodiment provides a method for high-value recycling of unsaturated polyester fiberglass waste, which mainly includes the following steps:

[0143] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0144] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0145] (3) The ultrafine FRP powder obtained in step (2) is uniformly mixed with methyl acrylate to form a mixture, and the mixture is added to a millstone-shaped solid phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, the FRP reinforced filler with viscosity reduction functionality is collected; wherein the process parameters of the millstone-shaped solid phase force chemical reactor are: grinding pressure of 2 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the millstone surface, cyclic grinding for 2 times, and a millstone speed of 50 rpm;

[0146] The mass ratio of the glass fiber reinforced plastic ultrafine powder to methyl acrylate in the mixture is 9:1;

[0147] (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0148] 100 parts of unsaturated polyester resin paste,

[0149] 5 parts of glass fiber reinforced filler,

[0150] 25 parts of chopped glass fiber;

[0151] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0152] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0153] Comparative Example 1

[0154] In Comparative Example 1, no glass fiber reinforced filler was added, and unsaturated polyester glass fiber reinforced plastic was prepared according to a traditional method, which mainly includes the following steps:

[0155] Prepare the following raw materials by weight and mix them evenly to form a mixed matrix:

[0156] 100 parts of unsaturated polyester resin paste,

[0157] 25 parts of chopped glass fiber;

[0158] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and an unsaturated polyester fiberglass was produced by a compression molding method.

[0159] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0160] Comparative Example 2

[0161] In Comparative Example 2, no viscosity reducer or small molecule monomer modifier was used to grind the ultrafine glass fiber reinforced plastic powder together with the ultrafine glass fiber reinforced plastic powder. The ultrafine glass fiber reinforced plastic powder was directly added as a filler. The method mainly includes the following steps:

[0162] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0163] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0164] (3) Using the ultrafine glass fiber reinforced plastic powder obtained in step (2) as raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0165] 100 parts of unsaturated polyester resin paste,

[0166] 5 parts of glass fiber reinforced plastic ultrafine powder,

[0167] 25 parts of chopped glass fiber;

[0168] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0169] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0170] Comparative Example 3

[0171] In Comparative Example 3, no viscosity reducer or small molecule monomer modifier was used to grind the ultrafine glass fiber reinforced plastic powder together with the ultrafine glass fiber reinforced plastic powder and acrylic acid. The method mainly includes the following steps:

[0172] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0173] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0174] (3) Using the ultrafine glass fiber reinforced plastic powder obtained in step (2) as raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0175] 100 parts of unsaturated polyester resin paste,

[0176] 4.5 parts of glass fiber reinforced plastic ultrafine powder,

[0177] 0.5 parts of acrylic acid,

[0178] 25 parts of chopped glass fiber;

[0179] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0180] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0181] Comparative Example 4

[0182] In Comparative Example 4, no viscosity reducer or small molecule monomer modifier was used to grind the ultrafine glass fiber reinforced plastic powder together with BYK-W 9010. The method mainly includes the following steps:

[0183] (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0184] (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 3 MPa, introduction of 15°C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 3 times, and grinding disc speed of 50 rpm;

[0185] (3) Using the ultrafine glass fiber reinforced plastic powder obtained in step (2) as raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix:

[0186] 100 parts of unsaturated polyester resin paste,

[0187] 4.5 parts of glass fiber reinforced plastic ultrafine powder,

[0188] BYK-W 9010 0.5 parts,

[0189] 25 parts of chopped glass fiber;

[0190] The obtained mixed matrix was leveled on a release cloth, and a release cloth was laid on the upper surface thereof, and the mixed matrix was aged at 40°C for 24 hours in a dark environment, after which the release cloth was removed and the FRP recycled product was produced by a compression molding method;

[0191] The obtained mixed matrix was tested for viscosity and tensile properties according to “2. Test method”.

[0192] 3. Test results

[0193] The viscosity test results of the mixed matrix in Examples 1 to 4 and Comparative Examples 1 to 4 are compared as shown in the following table:

[0194]

[0195] The viscosity test results clearly show that after mechanochemical co-grinding, the viscosity of the mixed matrix (unsaturated polyester prepreg) has been significantly improved. The viscosity of the mixed matrix in Examples 1 to 4 is comparable to that in the conventional process of Comparative Example 1 (less than 3.0×10 4cP). In Comparative Example 2, after directly adding FRP ultrafine powder, the viscosity of the mixed matrix increased sharply, exceeding the viscosity requirement of the normal production process. In Comparative Example 3, directly adding a small molecule monomer modifier to the resin paste did not significantly reduce the viscosity. In Comparative Example 4, directly adding BYK-W 9010, which is currently recognized for its excellent viscosity-reducing properties, still failed to reduce the viscosity of the mixed matrix to less than 3.0×10 4 cP, it is necessary to further increase the amount of viscosity reducer.

[0196] Through Examples 1 to 4, it is fully demonstrated that after unsaturated polyester fiberglass waste and conventional viscosity reducers or small molecule monomer modifiers are subjected to treatment including co-grinding, they can be directly used as reinforcing fillers and viscosity reducers, and can be used to replace conventional viscosity reducers and part of the glass fiber to prepare recycled unsaturated polyester fiberglass with qualified performance. This provides a modified fiberglass powder suitable for industrial production equipment for the recycling of unsaturated polyester fiberglass scraps, which is of great significance to actual production.

[0197] In Examples 1 to 4, it can be seen that the viscosity reduction effect of co-grinding with a small molecule monomer modifier and the expensive imported viscosity reducer BYK-W9010 is similar, and the production cost can be significantly reduced when the viscosity reducer is not used.

[0198] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for high-value recycling of unsaturated polyester fiberglass waste, characterized in that The main steps include: (1) After pre-treatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of not more than 10 mm; (2) adding the FRP crushed material obtained in step (1) into a grinding disc-shaped solid phase force chemical reactor for grinding and pulverizing, and collecting the FRP ultrafine powder after the grinding is completed; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 2-5 MPa, introduction of 10-25 °C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 2-5 times, and grinding disc speed of 40-50 rpm; (3) The ultrafine FRP powder obtained in step (2) is uniformly mixed with a viscosity reducer or a small molecule monomer modifier to form a mixture, and then added to a grinding disc-shaped solid phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, the FRP reinforcing filler with viscosity reduction functionality is collected; wherein the process parameters of the grinding disc-shaped solid phase force chemical reactor are: grinding pressure of 2-3 MPa, introduction of 10-25 ° C circulating cooling liquid to control the temperature of the grinding disc surface, cyclic grinding for 2-3 times, and grinding disc speed of 40-50 rpm; Wherein, the small molecule monomer modifier is any one of acrylic acid, triethylene glycol divinyl ether, methacrylate, and methyl acrylate; The mass ratio of the glass fiber reinforced plastic ultrafine powder to the viscosity reducer / small molecule monomer modifier in the mixture is 9: (0.5-1.5); (4) Using the glass fiber reinforced plastic filler with viscosity-reducing functionality obtained in step (3) as a raw material, raw materials including the following components are prepared by weight, and mixed evenly to form a mixed matrix: 100 parts of unsaturated polyester resin paste, 5~8 parts of glass fiber reinforced filler, 15-25 parts of glass fiber; The obtained mixed matrix is prepared according to a conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic.

2. The method according to claim 1, wherein: The crushing process of the glass fiber reinforced plastic crushed material in step (1) to an average particle size of not more than 10 mm is carried out by conventional tearing or crushing.

3. The method according to claim 1, wherein: In steps (2) and (3), a circulating cooling liquid at 10-25°C is introduced to control the temperature of the grinding disc surface, and the cooling liquid is water, ethylene glycol or glycerin.

4. The method according to claim 1, wherein: The viscosity reducer in step (3) includes any one of BYK-W9010, BYK-W 996, Walker VOK-9010A, and Chinese fir new material DP-8012.

5. The method according to claim 1, wherein: The glass fiber in step (4) includes any one of chopped glass fiber, glass cloth, glass tape, glass mat, and glass yarn.

6. The method according to claim 1, wherein: In step (4), the obtained mixed matrix is prepared according to a conventional unsaturated polyester glass fiber reinforced plastic preparation process to obtain recycled unsaturated polyester glass fiber reinforced plastic. Specifically, the obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on the upper surface thereof. The mixed matrix is aged at a temperature of 30-40°C in a light-proof environment for at least 24 hours, and then the release cloth is removed. The recycled glass fiber reinforced plastic product is obtained by a compression molding method.

7. The regenerated unsaturated polyester fiberglass reinforced plastics (FRP) prepared by the method for high-value recycling of unsaturated polyester fiberglass reinforced plastics (FRP) waste as claimed in claim 1.

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