Method for high-value recycling of unsaturated polyester glass fiber reinforced plastic waste material

Abstract

The invention belongs to the technical field of recycling and reusing of unsaturated polyester glass fiber reinforced plastic waste materials and preparation of regenerated unsaturated polyester glass fiber reinforced plastic, and relates to a method for high-value reusing of the unsaturated polyester glass fiber reinforced plastic waste materials. The method comprises the following steps: firstly, pre-treating unsaturated polyester glass fiber reinforced plastic waste materials, then grinding the unsaturated polyester glass fiber reinforced plastic waste materials by using a millstone-shaped solid-phase mechanochemical reactor to obtain superfine powder, then mixing the superfine powder with a viscosity reducer or a micromolecular monomer modifier, then co-grinding and crushing, and taking the obtained glass fiber reinforced plastic reinforcing filler with the viscosity reduction function as a raw material. And adding the mixture into unsaturated polyester resin paste to prepare the regenerated unsaturated polyester glass fiber reinforced plastic according to a conventional process. The glass fiber reinforced plastic reinforcing filler with the viscosity reduction function is used for replacing a conventional viscosity reducer and part of glass fibers to prepare regenerated unsaturated polyester glass fiber reinforced plastic with qualified performance, and a brand new way is provided for high-value recycling of unsaturated polyester glass fiber reinforced plastic waste materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of recycling and reuse of waste unsaturated polyester fiberglass and preparation of recycled unsaturated polyester fiberglass, and relates to a method for high-value reuse of waste unsaturated polyester fiberglass. Specifically, it involves using the waste materials generated during the production of unsaturated polyester fiberglass as reinforcing fillers and viscosity reducers after treatment, and using them to replace conventional viscosity reducers and part of the glass fibers to prepare qualified recycled unsaturated polyester fiberglass. In particular, it is directed to using an industrial grinding disc-shaped solid-phase force chemical reactor disclosed in Chinese invention patent CN114534660B to participate in the treatment of waste materials. Background Art

[0002] Unsaturated polyester fiberglass is a high-performance composite material with unsaturated polyester resin as the matrix and glass fibers and their products (such as glass cloth, tape, felt, yarn, etc.) as the reinforcing materials. It has good corrosion resistance, high strength, small thermal expansion coefficient, and is easy to process, and is widely used in various fields of the national economy such as petroleum, chemical industry, pesticides, medicine, dyes, electroplating, electrolysis, smelting, and light industry. Unsaturated polyester resin paste, as the main raw material of unsaturated polyester fiberglass, is a viscous liquid material based on unsaturated polyester resin and formulated by adding auxiliaries such as vinyl monomers (such as styrene), accelerators, and thixotropic agents. In the conventional forming process of unsaturated polyester fiberglass, usually, the unsaturated polyester resin paste is infiltrated into the surface and inside of the glass fiber mat, and is cured and molded by curing and molding under pressure to prepare unsaturated polyester fiberglass.

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

[0004] At present, most of the recycling methods for such waste unsaturated polyester fiberglass are based on physical recycling technologies. For example, fiberglass powder is prepared by mechanical crushing, and then the fiberglass powder is used as a filler for roads or building materials. This method is relatively mature, but the value of its recycled products is quite low. In actual situations, however, such waste unsaturated polyester fiberglass is still mostly disposed of by landfilling. In recent years, some researchers have also tried new ideas for the same-level recycling of preparing fiberglass recycled products using fiberglass waste materials, and certain results have been achieved.

[0005] For example, the inventor of the present invention previously applied for a patent for invention "Fiberglass Reinforced Plastic Recycled Products Using Waste Wind Turbine Blades as Raw Materials and Their Preparation Methods" (CN118063854A), which discloses a fiberglass reinforced plastic recycled product using waste wind turbine blades as raw materials and its preparation method. First, it provides a method for preparing highly compatible and reactive fillers using waste wind turbine blades, which is to add waste wind turbine blade products to a disk-type solid-phase force chemical reactor after pretreatment for grinding and crushing to obtain ultra-fine powder of wind turbine blades, and then mix the ultra-fine powder of wind turbine blades with an activator and co-grind to obtain highly compatible and reactive fillers; then use the highly compatible and reactive fillers as partial raw materials to prepare fiberglass reinforced plastic recycled products.

[0006] However, during the implementation and transformation test process of the above-mentioned patent technology-related topics, it was found that when this patent technology was applied to the actual production process, because it mainly used reactive activators, which were mainly used to improve the compatibility between the powder of wind turbine blades and epoxy resin, and limited by the laboratory conditions, it did not notice that adding the highly compatible and reactive fillers to the thermosetting resin system would cause a sharp increase in viscosity. The industrial production equipment based on conventional processes could not produce normally, and a large amount of viscosity-reducing agent needed to be added additionally to reduce the viscosity, which brought severe challenges to the existing production process and cost of fiberglass products. Therefore, it is very necessary to develop a recycling method that can be effectively implemented to realize the industrial recycling of waste unsaturated polyester fiberglass. Summary of the Invention

[0007] In order to solve the above problems in the prior art, the present invention provides a method for highly valuable reuse of waste unsaturated polyester fiberglass, and it is found that after treating waste unsaturated polyester fiberglass with a conventional viscosity-reducing agent or a small molecule monomer modifier including co-grinding, it can be directly used as a reinforcing filler and a viscosity-reducing agent, and use it to replace the conventional viscosity-reducing agent and part of the glass fiber to prepare qualified recycled unsaturated polyester fiberglass, providing a new way for the highly valuable recycling of waste unsaturated polyester fiberglass.

[0008] In order to achieve the above-mentioned purposes, the present invention is realized by a technical solution composed of the following technical measures.

[0009] The present invention provides a method for highly valuable reuse of waste unsaturated polyester fiberglass, mainly including the following steps:

[0010] (1) After the waste unsaturated polyester fiberglass is pretreated including washing, it is crushed to obtain fiberglass crushed materials with an average particle size not higher than 10 mm.

[0011] (2) Add the chopped FRP materials obtained in step (1) into a disk-shaped solid-state reactive grinding mill for grinding. After grinding is completed, collect the ultrafine FRP powder. Among them, the process parameters of the disk-shaped solid-state reactive grinding mill are as follows: the grinding pressure is 2 - 5 MPa, circulate cooling liquid at 10 - 25 °C to control the temperature of the disk surface, circulate and grind 2 - 5 times, and the rotational speed of the disk is 40 - 50 revolutions per minute;

[0012] (3) Mix the ultrafine FRP powder obtained in step (2) with a viscosity reducer or a small molecule monomer modifier evenly as a mixture, and then add it into the disk-shaped solid-state reactive grinding mill again for co-grinding. After grinding is completed, collect the FRP reinforcing filler with viscosity reduction functionality. Among them, the process parameters of the disk-shaped solid-state reactive grinding mill are as follows: the grinding pressure is 2 - 3 MPa, circulate cooling liquid at 10 - 25 °C to control the temperature of the disk surface, circulate and grind 2 - 3 times, and the rotational speed of the disk is 40 - 50 revolutions per minute;

[0013] Among them, 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 ultrafine FRP powder to the viscosity reducer / small molecule monomer modifier in the mixture is 9:(0.5 - 1.5);

[0015] (4) Use the FRP reinforcing filler with viscosity reduction functionality obtained in step (3) as a raw material. By weight, prepare the following components of raw materials, mix them evenly as a mixed matrix:

[0016] 100 parts of unsaturated polyester resin paste,

[0017] 5 - 8 parts of FRP reinforcing filler,

[0018] 15 - 25 parts of glass fiber;

[0019] Prepare the obtained mixed matrix according to the conventional preparation process of unsaturated polyester FRP to obtain recycled unsaturated polyester FRP.

[0020] In this article, the pretreatment described in step (1) includes washing. It mainly involves cleaning the surface of the waste unsaturated polyester FRP to remove impurities. Those skilled in the art can perform specific treatments according to the actual situation of the waste unsaturated polyester FRP to be recycled and utilized, in accordance with the existing technology.

[0021] It should be noted that the waste unsaturated polyester FRP described in step (1) is usually the scrap generated during the molding production of unsaturated polyester FRP. The unsaturated polyester resin in this type of waste has been cured.

[0022] In this text, the FRP crushed material obtained by the crushing treatment in step (1) with an average particle size not higher than 10 mm is sized to facilitate its placement into the disk-shaped solid-phase force chemical reactor for grinding. The crushing treatment method can adopt conventional tearing or crushing methods, such as being processed by existing conventional tearing or crushing equipment like single-axis and double-axis tearing machines, jaw crushers, etc.

[0023] Among them, the disk-shaped solid-phase force chemical reactor described in steps (2) and (3) is the industrial disk-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 disk-shaped solid-phase force chemical reactor is an industrial equipment finally improved based on the principle of the force chemical reactor disclosed in the prior authorized patent ZL95111258.9. It is significantly different from the structure of the laboratory prototype machine when ZL95111258.9 was applied. A new disk structure was designed for industrial high-efficiency force chemical grinding treatment. It was improved from the past vertical setting of the disk to a horizontal setting, and the disk size was greatly increased. Based on the horizontally set and large-sized disk, relevant fixed disk components and a hydraulic lifting system were innovatively designed, significantly improving its three-dimensional shear force.

[0025] Generally, the actual operation of the above-mentioned cyclic grinding process is to place the material into the disk-shaped solid-phase force chemical reactor for grinding, collect the product at the discharge end, and then place it into the disk-shaped solid-phase force chemical reactor again for grinding treatment. The above process is regarded as 1 cycle of cyclic grinding.

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

[0027] Based on the experimental conclusions of the prior invention patent "FRP regenerated products using waste wind turbine blades as raw materials and their preparation methods" (CN118063854A), the inventors of the present invention found that after substituting this patented technology into the actual production process, when preparing FRP regenerated products with epoxy resin as the matrix according to the method in its examples, adding this highly compatible and reactive filler to the epoxy resin would cause a sharp increase in viscosity, which is a defect not noticed during the sample production in the laboratory for this prior invention patent. And when directly adding the milled ultra-fine powder of wind turbine blades or FRP ultra-fine powder to the epoxy resin, there is also a significant increase in viscosity.

[0028] On this basis, when unsaturated polyester is selected as the matrix, the above-mentioned problem of increased viscosity also exists. Moreover, due to the obvious differences between the unsaturated polyester fiberglass production system and the epoxy resin fiberglass production system, especially in the unsaturated polyester fiberglass production system, the viscosity problem, under the magnification effect, makes it impossible for industrial production equipment based on conventional processes to operate normally. For example, in the molding process, the optimal molding viscosity is about 2.0×10 4 cP (Plastic Industry Handbook: Unsaturated Polyester Resins, Chemical Industry Press, 2001).

[0029] If ground fiberglass ultrafine powder (directly ground from unsaturated polyester fiberglass waste) or highly compatible and reactive fillers obtained according to the technical solution of the prior application for an invention patent (obtained by grinding unsaturated polyester fiberglass waste and then co-grinding with an activator) is directly added to the unsaturated polyester resin paste, after evaluation, it is considered that a viscosity reducer (about 1-5 wt%, varying according to the viscosity reduction effect of different viscosity reducers) needs to be additionally added to reduce the viscosity of the mixed matrix (the base material of fiberglass products composed of unsaturated polyester resin paste, fiberglass ultrafine powder / highly compatible and reactive fillers, and glass fibers) to below 3.0×10 4 cP so that industrial production equipment based on conventional processes can carry out production operations on a large scale and in batches, posing a severe challenge to the existing fiberglass product production process and cost. In addition, as the addition amount of the viscosity reducer increases, especially when a large amount of low-cost viscosity reducer needs to be added due to poor viscosity reduction effect, the mechanical properties of the prepared fiberglass products will deteriorate significantly.

[0030] Based on the above factual basis, during the process of trying to change the thinking, the inventor accidentally discovered that after co-grinding a viscosity reducer or a small molecule monomer modifier with fiberglass ultrafine powder (ground from unsaturated polyester fiberglass waste), the viscosity after blending with unsaturated polyester can be significantly reduced with relatively less addition or without additional addition of a viscosity reducer. On the one hand, the above research results enable no additional viscosity reducer to be added in the conventional unsaturated polyester fiberglass preparation process, and on the other hand, they also reduce the actual production cost, enabling the method of the present invention to be directly combined with the current unsaturated polyester fiberglass preparation process without obstacles to prepare regenerated unsaturated polyester fiberglass with qualified properties, providing a new way for the high-value recycling of unsaturated polyester fiberglass waste.

[0031] It should be emphasized that the prior invention patent of the inventor, "Glass Fiber Reinforced Plastic Recycled Products Using Waste Wind Turbine Blades as Raw Materials and Their Preparation Methods" (CN118063854A), discloses the co-milling force chemical reaction of the activator diethylenetriamine or ethylene glycol with ultra-fine powder of wind turbine blades. It mainly utilizes the force chemical reaction of polyamine or alcohol with epoxy resin to generate modified wind turbine blade powder containing amino and hydroxyl groups. The surface active groups of the powder have large polarity, and there is a strong intermolecular interaction with the epoxy groups and hydroxyl groups in the epoxy resin, resulting in improved compatibility. However, there is no viscosity reduction effect, nor is there a similar public report.

[0032] In this article, the viscosity reducer described in step (3) is a conventional industrial viscosity reducer in this field, such as BYK-W9010 of BYK Chemie, BYK-W 996 of BYK Chemie, VOK-9010A of Wacker, DP-8012 of Chinafir New Materials, etc.

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

[0034] It should be additionally noted that the small molecule monomer modifier described in step (3) is any one of acrylic acid, triethylene glycol divinyl ether, methacrylate, and methyl acrylate. In actual comparative experiments, it is found that based on the same addition amount, there are also very significant differences in the viscosity reduction effects of the above small molecule monomer modifiers after co-milling with glass fiber reinforced plastic ultra-fine powder. Based on the experimental results, the small molecule monomer modifier is further preferably acrylic acid.

[0035] In this article, the unsaturated polyester resin paste described in step (4) is a common term in the industry for the production link of unsaturated polyester glass fiber reinforced plastic. It is a viscous liquid material based on unsaturated polyester resin and formulated by adding auxiliaries such as vinyl monomers (such as styrene), shrinkage agents, flame retardants, initiators, accelerators, and thixotropic agents. It should be noted that it is not a single unsaturated resin.

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

[0037] In this text, in step (4), the obtained mixed matrix is prepared into recycled unsaturated polyester fiberglass according to the conventional preparation process of unsaturated polyester fiberglass. Those skilled in the art can know its specific process flow and operation according to the existing preparation process of fiberglass or the records in the existing technical literature.

[0038] To better illustrate the present invention and provide a reference technical solution, in step (4), the obtained mixed matrix is prepared into recycled unsaturated polyester fiberglass according to the conventional preparation process of unsaturated polyester fiberglass. Specifically, the obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface, and it is cured at a temperature of 30-40 °C for at least 24 h in a light-shielded environment. Then, the release cloth is removed, and a fiberglass recycled product is obtained by using a compression molding method.

[0039] In this text, the mixing evenly, leveling, curing, and compression molding all follow the conventional principles in chemical engineering processes. Those skilled in the art can perform specific operations according to common knowledge.

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

[0041] (1) The present invention provides a method for high-value recycling of waste unsaturated polyester fiberglass. Through the strong three-dimensional shear force of a disk-shaped solid-phase force chemical reactor, a viscosity reducer or a small molecule monomer modifier is grafted onto the surface of the ultra-fine fiberglass powder. Compared with directly adding a viscosity reducer or a small molecule monomer modifier to the mixed matrix, the viscosity reduction effect is more significant, and additional viscosity reducers can be greatly reduced or not added.

[0042] (2) The technical solution of the present invention uses waste unsaturated polyester fiberglass scraps as raw materials, and can achieve the same-level recycling in unsaturated polyester fiberglass products. Different from the existing physical recycling technologies that use unsaturated polyester fiberglass powder in road asphalt or concrete building materials, it 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 obstacles to prepare qualified recycled unsaturated polyester fiberglass. At the same time, the operation is simple, the recycling cost is low, it is easy to scale up production, and there is no waste generated and no secondary pollution during the recycling process, and it has a clear industrialization prospect. Description of the Drawings

[0044] Figure 1 It is a physical photo of the waste unsaturated polyester fiberglass used in step (1) of Example 1 of the present invention (left) and the viscosity-reducing functional fiberglass reinforcing filler obtained in step (3) (right).

[0045] Figure 2This is a physical photo of the unsaturated polyester resin paste used in step (4) of Embodiment 1 of the present invention. Detailed implementation manners

[0046] To further understand the present invention, the preferred implementation manners of the present invention will be described below in conjunction with embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention. Those skilled in the art can draw on the content of this article and appropriately improve the process parameters to achieve. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all regarded as included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make changes or appropriate modifications and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present invention to implement and apply the technical solution of the present invention. Although it is believed that those of ordinary skill in the art are fully aware of the following terms, the following definitions are still presented to help illustrate the subject matter disclosed by the present invention.

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

[0048] (1) After the waste unsaturated polyester fiberglass is pretreated including washing, it is crushed to a fiberglass crushed material with an average particle size not higher than 10 mm;

[0049] (2) The fiberglass crushed material obtained in step (1) is added to a disk-shaped solid-phase force chemical reactor for grinding and pulverization. After the grinding is completed, fiberglass ultrafine powder is collected; wherein, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 2-5 MPa, circulating cooling liquid at 10-25 °C is introduced to control the temperature of the disk surface of the grinding disk, and the circulating grinding is carried out 2-5 times, and the rotation speed of the grinding disk is 40-50 revolutions per minute;

[0050] (3) The fiberglass ultrafine powder obtained in step (2) is mixed evenly with a viscosity reducer or a small molecule monomer modifier as a mixture, and then added to the disk-shaped solid-phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, a fiberglass reinforcing filler with viscosity-reducing functionality is collected; wherein, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 2-3 MPa, circulating cooling liquid at 10-25 °C is introduced to control the temperature of the disk surface of the grinding disk, and the circulating grinding is carried out 2-3 times, and the rotation speed of the grinding disk is 40-50 revolutions per minute;

[0051] Among them, 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 and the viscosity reducing agent / small molecule monomer modifier in the mixture is 9:(0.5~1.5);

[0053] (4) Using the viscosity-reducing functional glass fiber reinforced plastic filler obtained in step (3) as a raw material, prepare the following raw materials by weight, and mix them evenly as a mixed matrix:

[0054] 100 parts of unsaturated polyester resin paste,

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

[0056] 15~25 parts of glass fiber;

[0057] Prepare the obtained mixed matrix into recycled unsaturated polyester glass fiber reinforced plastic according to the conventional unsaturated polyester glass fiber reinforced plastic preparation process.

[0058] In this article, the pretreatment described in step (1) includes washing. It mainly cleans the surface of the waste unsaturated polyester glass fiber reinforced plastic and removes impurities. Those skilled in the art can perform specific treatments according to the actual situation of the waste unsaturated polyester glass fiber reinforced plastic to be recycled and utilized, according to the existing technology.

[0059] It should be noted that the waste unsaturated polyester glass fiber reinforced plastic described in step (1) is usually the scraps generated during the molding production of unsaturated polyester glass fiber reinforced plastic. The unsaturated polyester resin in this type of waste has been cured.

[0060] In this article, the glass fiber reinforced plastic crushed material obtained by crushing in step (1) to an average particle size not higher than 10 mm is a size that facilitates its placement in a disk-shaped solid-phase force chemical reactor for grinding. The crushing treatment method can adopt conventional tearing or crushing methods. In one implementation, 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] Among them, the disk-shaped solid-phase force chemical reactor described in steps (2) and (3) is the industrial disk-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 disk-shaped solid-phase force chemical reactor is an industrial device finally improved based on the principle of the force chemical reactor disclosed in the previously authorized patent ZL95111258.9. It is significantly different from the structure of the laboratory prototype machine when applying for ZL95111258.9. A new disk structure is designed for industrial high-efficiency force chemical milling treatment. The disk is changed from the vertical setting in the past to the horizontal setting, and the disk size is greatly increased. Based on the horizontally set and large-sized disk, relevant fixed disk components and hydraulic lifting systems are innovatively designed, greatly improving its three-dimensional shear force.

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

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

[0065] Based on the experimental conclusions of the previously applied invention patent "Fiberglass Reinforced Plastic Recycling Products Using Waste Wind Turbine Blades as Raw Materials and Their Preparation Methods" (CN118063854A), the inventors of the present invention found that after substituting this patented technology into the actual production process, when preparing fiberglass reinforced plastic recycling products with epoxy resin as the matrix according to the method in its examples, adding this highly compatible and reactive filler to the epoxy resin will cause a sharp increase in viscosity, which is a defect not noticed during the sample production in the laboratory for this previously applied invention patent. And when directly adding the milled ultrafine powder of wind turbine blades or fiberglass ultrafine powder to the epoxy resin, there is also a significant increase in viscosity.

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

[0067] If the milled glass fiber reinforced plastic (GFRP) ultrafine powder (directly milled from waste GFRP made of unsaturated polyester) or the highly compatible and reactive filler obtained according to the technical solution of the prior application for an invention patent (obtained by milling waste GFRP made of unsaturated polyester and then co-milling with an activator) is directly added to the unsaturated polyester resin paste, after evaluation, it is considered that a viscosity reducer (about 1-5 wt%, varying according to the viscosity reduction effect of different viscosity reducers) needs to be additionally added to reduce the viscosity of the mixed matrix (the base material of the GFRP product composed of unsaturated polyester resin paste, GFRP ultrafine powder / highly compatible and reactive filler, and glass fiber) to below 3.0×10 4 cP so that industrial production equipment based on conventional processes can carry out large-scale and batch production operations, posing a severe challenge to the existing production process and cost of GFRP products. In addition, as the addition amount of the viscosity reducer increases, especially when a large amount of low-cost viscosity reducer needs to be added due to poor viscosity reduction effect, the mechanical properties of the prepared GFRP products will deteriorate significantly.

[0068] Based on the above factual basis, during the process of trying to change the thinking, the inventor accidentally found that after co-milling the viscosity reducer or small molecule monomer modifier with the GFRP ultrafine powder (milled from waste GFRP made of unsaturated polyester), the viscosity after blending with unsaturated polyester can be significantly reduced with relatively less addition or without adding an additional viscosity reducer. On the one hand, the above research results enable no additional viscosity reducer to be added in the conventional preparation process of unsaturated polyester GFRP, and on the other hand, it also reduces the actual production cost, enabling the method of the present invention to be directly combined with the current unsaturated polyester GFRP preparation process without obstacles, and preparing qualified recycled unsaturated polyester GFRP, providing a new way for the high-value recycling of waste GFRP.

[0069] It should be emphasized that in the inventor's prior application for an invention patent "Fiberglass Reinforced Plastic Recycled Products Using Waste Wind Turbine Blades as Raw Materials and Their Preparation Methods" (CN118063854A), the mechanochemical reaction of the activator diethylenetriamine or ethylene glycol and the ultrafine powder of wind turbine blades was disclosed. It mainly utilized the mechanochemical reaction of polyamine or alcohol with epoxy resin to generate modified wind turbine blade powder containing amino and hydroxyl groups. The surface active groups of the powder have large polarity and strong intermolecular interactions with the epoxy groups and hydroxyl groups in the epoxy resin, improving the compatibility, but there is no viscosity reduction effect, nor is there a similar public report.

[0070] In this article, the viscosity reducer described in step (3) is a conventional industrial viscosity reducer in the art. In one of the embodiments, for example, any one of BYK-W 9010 of BYK Chemie, BYK-W 996 of BYK Chemie, VOK-9010A of Wacker, and DP-8012 of China Fir New Materials is selected.

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

[0072] It should be added that the small molecule monomer modifier described 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, there are also very significant differences in the viscosity reduction effects of the above-mentioned small molecule monomer modifiers and the ultra-fine glass fiber powder after co-grinding. Based on the experimental results, in one preferred embodiment, the small molecule monomer modifier is further preferably acrylic acid.

[0073] In one embodiment, the mass ratio of the ultra-fine glass fiber powder to the viscosity reducer / small molecule monomer modifier in the mixture described 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 between them.

[0074] In this article, the unsaturated polyester resin paste described in step (4) is a common term in the industry for the production process of unsaturated polyester fiberglass. It is a viscous liquid material based on unsaturated polyester resin and formulated by adding auxiliaries such as vinyl monomers (such as styrene), shrinkage agents, flame retardants, initiators, accelerators, and thixotropic agents. 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 commonly selected glass fiber reinforcing material in the fiberglass preparation process. Those skilled in the art can select appropriate glass fibers according to the existing fiberglass preparation process or the records in the existing technical literature. In one embodiment, for example, it includes any one of chopped glass fibers, glass cloth, glass tape, glass mat, and glass yarn.

[0076] In one embodiment, the fiberglass reinforcing filler described in step (4) is 5 - 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 between them.

[0077] In one of the embodiments, the glass fiber in step (4) is 15 to 25 parts, such as 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 text, the obtained mixed matrix is prepared into a recycled unsaturated polyester fiberglass according to the conventional preparation process of unsaturated polyester fiberglass. Those skilled in the art can know the specific process flow and operation according to the existing preparation process of fiberglass or the records in the prior art documents.

[0079] To better illustrate the present invention and provide a reference implementation, the obtained mixed matrix is prepared into a recycled unsaturated polyester fiberglass according to the conventional preparation process of unsaturated polyester fiberglass in step (4). Specifically, the obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface, and it is cured at a temperature of 30 to 40 °C for at least 24 h in a light-shielded environment. Then, the release cloth is removed, and a fiberglass recycled product is obtained by using a compression molding method.

[0080] In this text, the mixing evenly, leveling, curing, and compression molding all follow the conventional principles in chemical engineering processes, and those skilled in the art can perform specific operations according to common knowledge.

[0081] The present application will be further explained in detail with reference to the embodiments below. However, those skilled in the art should understand that these embodiments are provided only for the purpose of illustration and are not intended to limit the present application.

[0082] Embodiment

[0083] The implementation scheme of the present application will be described in detail below in combination with the embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For those reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase. The present application should not be construed as being limited by the specific embodiments described.

[0084] 1. Raw materials

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

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

[0087] BYK-W 9010 is purchased from BYK Chemie.

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

[0089] 2. Test methods

[0090] In the examples and comparative examples of the present invention, the viscosity of the mixed matrix is measured in accordance with ISO / TS 23927:2024.

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

[0092] Example 1

[0093] A method for high-value reuse of waste unsaturated polyester fiberglass in this example mainly includes the following steps:

[0094] (1) After the waste unsaturated polyester fiberglass as shown in Figure 1 (left) undergoes pretreatment including washing, it is crushed into fiberglass crushed materials with an average particle size of about 6 mm;

[0095] (2) The fiberglass crushed materials obtained in step (1) are added to a disk-shaped solid-phase force chemical reactor for grinding and pulverization. After the grinding is completed, fiberglass ultrafine powder is collected; among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 3 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the circulating grinding is carried out 3 times, and the disk rotation speed is 50 revolutions per minute;

[0096] (3) The fiberglass ultrafine powder obtained in step (2) is mixed evenly with acrylic acid as a mixture, and then added to the disk-shaped solid-phase force chemical reactor again for co-grinding and pulverization. After the grinding is completed, a fiberglass reinforcing filler with viscosity-reducing functionality is collected. The physical diagram of the fiberglass reinforcing filler with viscosity-reducing functionality is as shown in Figure 1 (right); among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 2 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the circulating grinding is carried out 2 times, and the disk rotation speed is 50 revolutions per minute;

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

[0098] (4) Using the fiberglass reinforcing filler with viscosity-reducing functionality obtained in step (3) as a raw material, according to the weight parts, the following components of raw materials are prepared, and after mixing evenly, it is used as a mixed matrix:

[0099] Unsaturated polyester resin paste 100 parts,

[0100] Fiberglass reinforcing filler 5 parts,

[0101] Chopped glass fibers 25 parts;

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

[0103] The obtained mixed matrix is leveled on the release cloth, and a release cloth is laid on its upper surface. It is cured at 40 °C for 24 h in a light-shielded environment, and then the release cloth is removed. A glass fiber reinforced plastic recycled product is prepared by using a compression molding method;

[0104] The viscosity and tensile properties of the obtained mixed matrix are tested according to the "2. Test Method".

[0105] Example 2

[0106] A method for high-value reuse of waste unsaturated polyester glass fiber reinforced plastics in this example mainly includes the following steps:

[0107] (1) After the waste unsaturated polyester glass fiber reinforced plastics are pretreated including washing, they are crushed to obtain glass fiber reinforced plastic crushed materials with an average particle size of about 6 mm;

[0108] (2) The glass fiber reinforced plastic crushed materials obtained in step (1) are added to a disk-shaped solid-phase force chemical reactor for grinding and pulverization. After the grinding is completed, glass fiber reinforced plastic ultrafine powder is collected. Among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 3 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the circulating grinding is carried out 3 times, and the disk rotation speed is 50 revolutions per minute;

[0109] (3) The glass fiber reinforced plastic ultrafine powder obtained in step (2) and triethylene glycol divinyl ether are mixed evenly as a mixture, and then added to the disk-shaped solid-phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, glass fiber reinforced plastic reinforcing filler with viscosity-reducing functionality is collected. Among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 2 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the circulating grinding is carried out 2 times, and the disk rotation speed is 50 revolutions per minute;

[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 reinforcing filler with viscosity-reducing functionality obtained in step (3) as a raw material, according to the weight parts, the following components are prepared, and after mixing evenly, they are used as a mixed matrix:

[0112] 100 parts of unsaturated polyester resin paste,

[0113] 5 parts of glass fiber reinforced plastic reinforcing filler,

[0114] 25 parts of chopped glass fiber;

[0115] The obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface. It is cured for 24 h at a temperature of 40 °C in a light-shielded environment. After that, the release cloth is removed, and a regenerated FRP product is obtained by using a compression molding method.

[0116] The viscosity and tensile properties of the obtained mixed matrix are tested according to the "2. Test Method".

[0117] Example 3

[0118] A method for high-value reuse of waste unsaturated polyester FRP in this example mainly includes the following steps:

[0119] (1) After the waste unsaturated polyester FRP is pretreated including washing, it is crushed into FRP crushed materials with an average particle size of about 6 mm.

[0120] (2) The FRP crushed materials obtained in step (1) are added to a disk-shaped solid-phase force chemical reactor for grinding and pulverization. After the grinding is completed, FRP ultrafine powder is collected. Among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 3 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the cycle grinding is 3 times, and the disk rotation speed is 50 revolutions per minute.

[0121] (3) The FRP ultrafine powder obtained in step (2) and methacrylate are mixed evenly as a mixture, and then added to the disk-shaped solid-phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, a viscosity-reducing functional FRP reinforcing filler is collected. Among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 2 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the cycle grinding is 2 times, and the disk rotation speed is 50 revolutions per minute.

[0122] The mass ratio of the FRP ultrafine powder to methacrylate in the mixture is 9:1.

[0123] (4) Using the viscosity-reducing functional FRP reinforcing filler obtained in step (3) as a raw material, according to the weight parts, the following components of raw materials are prepared, and after mixing evenly, it is used as a mixed matrix:

[0124] Unsaturated polyester resin paste 100 parts,

[0125] FRP reinforcing filler 5 parts,

[0126] Chopped glass fiber 25 parts;

[0127] The obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface. It is cured for 24 h at a temperature of 40 °C in a light-shielded environment. After that, the release cloth is removed, and a glass fiber reinforced plastic recycled product is obtained by using a compression molding method;

[0128] The viscosity and tensile properties of the obtained mixed matrix are tested according to the "2. Test Method".

[0129] Example 4

[0130] A method for high-value reuse of waste unsaturated polyester fiberglass in this example mainly includes the following steps:

[0131] (1) After the waste unsaturated polyester fiberglass is pretreated including washing, it is crushed to fiberglass crushed material with an average particle size of about 6 mm;

[0132] (2) The fiberglass crushed material obtained in step (1) is added to a disk-shaped solid-phase force chemical reactor for grinding and pulverization. After the grinding is completed, fiberglass ultrafine powder is collected. Among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 3 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface of the grinding disk, the circulating grinding is carried out 3 times, and the rotating speed of the grinding disk is 50 revolutions per minute;

[0133] (3) The fiberglass ultrafine powder obtained in step (2) is mixed evenly with BYK-W 9010 as a mixture, and then added to the disk-shaped solid-phase force chemical reactor for co-grinding and pulverization. After the grinding is completed, a fiberglass reinforcing filler with viscosity-reducing functionality is collected. Among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 2 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface of the grinding disk, the circulating grinding is carried out 2 times, and the rotating speed of the grinding disk is 50 revolutions per minute;

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

[0135] (4) Using the fiberglass reinforcing filler with viscosity-reducing functionality obtained in step (3) as a raw material, according to the weight parts, the following components of raw materials are prepared, and after mixing evenly, it is used as a mixed matrix:

[0136] Unsaturated polyester resin paste 100 parts,

[0137] Fiberglass reinforcing filler 5 parts,

[0138] Chopped glass fiber 25 parts;

[0139] The obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface. It is cured for 24 h at a temperature of 40 °C in a light-proof environment. Then, the release cloth is removed, and a regenerated FRP product is obtained by using a compression molding method.

[0140] The viscosity and tensile properties of the obtained mixed matrix are tested according to the "2. Test Method".

[0141] Example 5

[0142] A method for high-value reuse of waste unsaturated polyester FRP in this example mainly includes the following steps:

[0143] (1) After the waste unsaturated polyester FRP is pretreated including washing, it is crushed into FRP crushed materials with an average particle size of about 6 mm.

[0144] (2) The FRP crushed materials obtained in step (1) are added to a disk-shaped solid-state reactive grinding reactor for grinding and pulverization. After the grinding is completed, FRP ultrafine powder is collected. Among them, the process parameters of the disk-shaped solid-state reactive grinding reactor are: the grinding pressure is 3 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the cycle grinding is 3 times, and the disk rotation speed is 50 revolutions per minute.

[0145] (3) The FRP ultrafine powder obtained in step (2) and methyl acrylate are mixed evenly as a mixture, and then added to the disk-shaped solid-state reactive grinding reactor for co-grinding and pulverization. After the grinding is completed, FRP reinforcing filler with viscosity-reducing functionality is collected. Among them, the process parameters of the disk-shaped solid-state reactive grinding reactor are: the grinding pressure is 2 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the cycle grinding is 2 times, and the disk rotation speed is 50 revolutions per minute.

[0146] The mass ratio of the FRP ultrafine powder to methyl acrylate in the mixture is 9:1.

[0147] (4) Using the FRP reinforcing filler with viscosity-reducing functionality obtained in step (3) as a raw material, according to the weight parts, the following components of raw materials are prepared, and after mixing evenly, it is used as a mixed matrix:

[0148] 100 parts of unsaturated polyester resin paste,

[0149] 5 parts of FRP reinforcing filler,

[0150] 25 parts of chopped glass fiber;

[0151] The obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface. It is cured for 24 h at a temperature of 40 °C in a light-proof environment. Then, the release cloth is removed, and a regenerated FRP product is obtained by using a compression molding method.

[0152] Test the viscosity and tensile properties of the obtained mixed matrix according to "2. Test Method".

[0153] Comparative Example 1

[0154] No fiberglass reinforced filler was added in Comparative Example 1, and unsaturated polyester fiberglass was prepared by a traditional method, which mainly included the following steps:

[0155] Weigh the following raw materials by parts by weight, mix them evenly and use them as the mixed matrix:

[0156] 100 parts of unsaturated polyester resin paste,

[0157] 25 parts of chopped glass fiber;

[0158] Level the obtained mixed matrix on the release cloth, lay a release cloth on its upper surface, cure it for 24 h at 40 °C in a light-shielded environment, then remove the release cloth, and use the compression molding method to obtain unsaturated polyester fiberglass;

[0159] Test the viscosity and tensile properties of the obtained mixed matrix 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 co-grind and pulverize with the ultra-fine fiberglass powder, and the ultra-fine fiberglass powder was directly added as a filler, which mainly included the following steps:

[0162] (1) After the waste of unsaturated polyester fiberglass is pretreated including washing, it is crushed to obtain fiberglass crushed material with an average particle size of about 6 mm;

[0163] (2) Add the fiberglass crushed material obtained in step (1) into a disk-shaped solid-phase force chemical reactor for grinding and pulverization. After the grinding is completed, collect the ultra-fine fiberglass powder; among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 3 MPa, and 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface of the grinding disk, and the circulating grinding is carried out 3 times, and the rotation speed of the grinding disk is 50 revolutions per minute;

[0164] (3) Use the ultra-fine fiberglass powder obtained in step (2) as the raw material, weigh the following raw materials by parts by weight, mix them evenly and use them as the mixed matrix:

[0165] 100 parts of unsaturated polyester resin paste,

[0166] 5 parts of ultra-fine fiberglass powder,

[0167] 25 parts of chopped glass fiber;

[0168] The obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface. It is cured for 24 h at a temperature of 40 °C in a light-shielded environment. After that, the release cloth is removed, and a regenerated FRP product is prepared by a compression molding method;

[0169] The viscosity and tensile properties of the obtained mixed matrix are tested according to the "2. Test Method".

[0170] Comparative Example 3

[0171] In Comparative Example 3, no viscosity reducer or small molecule monomer modifier was used to co-grind and pulverize with the FRP ultrafine powder. The FRP ultrafine powder and acrylic acid were directly added, which mainly included the following steps:

[0172] (1) After the waste unsaturated polyester FRP is pretreated including washing, it is crushed to FRP crushed material with an average particle size of about 6 mm;

[0173] (2) The FRP crushed material obtained in step (1) is added to a disk-shaped solid-phase force chemical reactor for grinding and pulverization. After the grinding is completed, the FRP ultrafine powder is collected. Among them, the process parameters of the disk-shaped solid-phase force chemical reactor are: the grinding pressure is 3 MPa, 15 °C circulating cooling liquid is introduced to control the temperature of the disk surface, the circulating grinding is carried out 3 times, and the disk rotation speed is 50 revolutions per minute;

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

[0175] 100 parts of unsaturated polyester resin paste,

[0176] 4.5 parts of FRP ultrafine powder,

[0177] 0.5 part of acrylic acid,

[0178] 25 parts of chopped glass fiber;

[0179] The obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface. It is cured for 24 h at a temperature of 40 °C in a light-shielded environment. After that, the release cloth is removed, and a regenerated FRP product is prepared by a compression molding method;

[0180] The viscosity and tensile properties of the obtained mixed matrix are tested according to the "2. Test Method".

[0181] Comparative Example 4

[0182] In Comparative Example 4, no viscosity reducer or small molecule monomer modifier was used for co-grinding and pulverizing with the glass fiber reinforced plastic (GFRP) ultrafine powder. Instead, the GFRP ultrafine powder and BYK-W 9010 were directly added. The main steps are as follows:

[0183] (1) After the waste unsaturated polyester GFRP is pretreated including washing, it is crushed to GFRP crushed materials with an average particle size of about 6 mm;

[0184] (2) The GFRP crushed materials obtained in step (1) are added to a disk-shaped solid-phase reactive grinding reactor for grinding and pulverizing. After the grinding is completed, the GFRP ultrafine powder is collected. Among them, the process parameters of the disk-shaped solid-phase reactive grinding reactor are: the grinding pressure is 3 MPa, circulating cooling liquid at 15 °C is introduced to control the temperature of the disk surface, the circulating grinding is carried out 3 times, and the disk rotation speed is 50 revolutions per minute;

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

[0186] 100 parts of unsaturated polyester resin paste,

[0187] 4.5 parts of GFRP ultrafine powder,

[0188] 0.5 part of BYK-W 9010,

[0189] 25 parts of chopped glass fibers;

[0190] The obtained mixed matrix is leveled on a release cloth, and a release cloth is laid on its upper surface. It is cured at 40 °C for 24 h in a light-shielded environment, and then the release cloth is removed. A recycled GFRP product is obtained by using a compression molding method;

[0191] The obtained mixed matrix is tested for viscosity and tensile properties according to the "2. Test Method".

[0192] 3. Test Results

[0193] The viscosity test results of the mixed matrices in Examples 1-4 and Comparative Examples 1-4 are compared as follows in the table:

[0194]

[0195] It can be clearly seen from the viscosity test results that after mechanochemical co-grinding, the viscosity of the mixed matrix (unsaturated polyester prepreg) has been significantly improved. The viscosities of the mixed matrices in Examples 1-4 are comparable to those in the traditional process of Comparative Example 1 (less than 3.0×10 4cP). In Comparative Example 2, after directly adding the glass fiber reinforced plastic ultrafine powder, the viscosity of the mixed matrix increased sharply, exceeding the requirements for viscosity in the normal production process. In Comparative Example 3, directly adding the small molecule monomer modifier to the resin paste did not significantly reduce the viscosity; in Comparative Example 4, after directly adding BYK-W 9010, which is currently recognized as having excellent viscosity reduction performance, even at an addition amount of only 0.5 wt%, the viscosity of the mixed matrix could still not be made less than 3.0×10 4 cP, and it was necessary to further increase the addition amount of the viscosity reducing agent.

[0196] Through Examples 1 to 4, it was fully demonstrated that after treating the waste glass fiber reinforced plastic of unsaturated polyester with a conventional viscosity reducing agent or a small molecule monomer modifier through co-grinding, etc., it could be directly used as a reinforcing filler and a viscosity reducing agent, and using it to replace the conventional viscosity reducing agent and part of the glass fiber to prepare a regenerated unsaturated polyester glass fiber reinforced plastic with qualified performance. This provided a modified glass fiber reinforced plastic powder suitable for industrial production equipment for the recycling of the waste materials of unsaturated polyester glass fiber reinforced plastic, which was of great significance to actual production.

[0197] In Examples 1 to 4, it could also be seen that there was little difference in the viscosity reduction effect between using the small molecule monomer modifier and co-grinding with the expensive imported viscosity reducing agent BYK-W9010, and the production cost could be significantly reduced without using the viscosity reducing agent.

[0198] The above examples are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above examples. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope 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 pretreatment including washing, the unsaturated polyester fiberglass waste is crushed into fiberglass crushed materials with an average particle size of no 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 reducing agent or a small molecule monomer modifier to form a mixed material, 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 reducing 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 a 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 ultrafine glass fiber reinforced plastic powder to the viscosity reducer / small molecule monomer modifier in the mixture is 9: (0.5-1.5); (4) Using the glass fiber reinforced plastics 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, Glass fiber 15~25 parts; 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, characterized in that: The crushing process of the glass fiber reinforced plastic crushed material in step (1) to an average particle size of no more than 10 mm is carried out by conventional tearing or crushing.

3. The method according to claim 1, characterized in that: 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.

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

5. The method according to claim 1, characterized in that: 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, characterized in that: 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 to 40° C. in a light-proof environment for at least 24 hours, and then the release cloth is removed, and the recycled glass fiber reinforced plastic product is obtained by a compression molding method.

7. The regenerated unsaturated polyester fiberglass obtained by the method for high-value recycling of unsaturated polyester fiberglass waste as claimed in claim 1.

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