Preparation method and product of wind turbine blade recycled material reinforced wood-plastic composite material

Abstract

The present invention discloses a preparation method and product of a wind turbine blade recycled material reinforced wood-plastic composite material. A preparation method of a wind turbine blade recycled material reinforced wood-plastic composite material comprises the following steps: S1: low-temperature plasma treatment of wind turbine blade recycled resin; S2: compounding wind turbine blade recycled fiber with polyolefin to obtain wind turbine blade recycled fiber reinforced polyolefin masterbatch; S3: mixing, granulating and extruding the modified wind turbine blade recycled resin and wind turbine blade recycled fiber reinforced polyolefin masterbatch with polyolefin and / or maleic anhydride grafted polyolefin, biomass fiber and other additives to obtain a waste wind turbine blade recycled fiber reinforced polyolefin-based wood-plastic composite material. The present invention is conducive to overcoming the defects of the prior art that the wind turbine blade recycled fiber cannot be well utilized and the performance is insufficient when preparing wood-plastic composite materials. The present invention also provides a wind turbine blade recycled material reinforced wood-plastic composite material product.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material manufacturing, and relates to a preparation method and a product of a wind turbine blade recycled material reinforced wood-plastic composite material, and specifically to a preparation method and a product of a waste wind turbine blade reinforced polyolefin-based wood-plastic composite material. Background Art

[0002] China's wind power industry is developing rapidly and is about to face the challenge of large-scale wind turbine blade retirement. The harmless treatment, high-value utilization and resource utilization of discarded wind turbine blades have become key issues for the sustainable development of the wind power industry. At present, the main components of retired wind turbine blades are epoxy resin and glass fiber, and they also contain a small amount of metal, balsa wood and foam. However, since epoxy resin is a thermosetting material, it is difficult to recycle and reuse. Globally, the main recycling technologies for discarded wind turbine blades include physical recycling, thermal recycling and chemical recycling. Thermal recycling equipment is expensive and easily produces toxic and harmful waste gas; chemical recycling has high energy consumption and large solvent usage. Therefore, these technologies are difficult to achieve industrialization, while physical recycling has greater industrialization potential. However, due to the limitations of the recycling process, currently only cured epoxy resin powder and glass fiber short fibers containing cured epoxy resin (purity 60-90%) can be obtained through cutting, crushing, grinding and other methods, and the resulting materials can often only be used for low-value materials. This limits the application areas and performance of recycled materials, greatly affects how to achieve harmless and high-value utilization of discarded wind turbine blades, and has a significant impact on the sustainable development of the wind power industry.

[0003] On the other hand, polyolefins are a general-purpose plastic that is widely used in daily life. In order to improve the strength of polyolefins, glass fibers are usually added to plastics. However, the fiber components in recycled wind turbine blades are impure, and there are many defects in the materials during the mechanical recycling process, which leads to poor reinforcement effect of recycled fibers on polyolefins, thus hindering its industrial application. Therefore, how to modify the materials and improve the processes of discarded wind turbine blades to significantly improve the performance of composite materials and apply them to higher-end fields has become a key issue in whether discarded wind turbine blades can achieve high-value applications.

[0004] Wood-plastic composites are innovative materials made from waste thermoplastics, biomass fibers and a variety of additives through extrusion, injection molding, hot pressing and other processes. They are mainly used in indoor and outdoor decoration, garden landscaping and other fields. Since the selling price and added value of wood-plastic composites are relatively high, the high-value utilization of waste wind turbine blades in the field of wood-plastic composites is considered to be one of the potential ways. However, due to the impure fiber components recycled from waste wind turbine blades, there are many defects in the materials during the mechanical recycling process, and the reinforcement effect on wood-plastic composites is not obvious. In addition, since the cost of the recycling process is higher than the existing wood-plastic composite formula system, this has an adverse effect on industrialization. Therefore, how to modify the materials and improve the process of waste wind turbine blades, so as to greatly improve the strength of wood-plastic composites and enable them to be used in more high-end fields, will become a key issue in whether waste wind turbine blades can be used in the high-value application of wood-plastic composites.

[0005] There is a lack of relevant technology in the existing technology as a reference. It is necessary to propose a new technical solution to solve the problem of resource utilization of discarded wind turbine blades in the field of wood-plastic composite materials and contribute to the sustainable development of the wind power industry and the wood-plastic composite material industry. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a waste wind turbine blade reinforced polyolefin-based wood plastic and a preparation method thereof that overcomes the defects of existing materials, has a more reasonable process, has better product performance, and can effectively utilize recycled fibers from wind turbine blades.

[0007] The technical scheme adopted by the present invention is: a preparation method of a wind turbine blade recycled material reinforced wood-plastic composite material, comprising the following steps: S1: modifying the wind turbine blade recycled resin by a low-temperature plasma treatment process using a low-temperature plasma treatment machine for powder to obtain a modified wind turbine blade recycled resin; S2: compounding the wind turbine blade recycled fiber with polyolefin, and obtaining a wind turbine blade recycled fiber reinforced polyolefin masterbatch through a granulation process; S3: mixing the modified wind turbine blade recycled resin obtained in step S1 and the wind turbine blade recycled fiber reinforced polyolefin masterbatch obtained in step S2 with polyolefin and / or maleic anhydride grafted polyolefin, biomass fiber and one or more of an antioxidant, an anti-aging agent, an anti-ultraviolet agent, calcium carbonate, a lubricant, and a pigment, and mixing the auxiliary agent, granulating, and extruding to obtain a waste wind turbine blade recycled fiber reinforced polyolefin-based wood-plastic composite material.

[0008] As a further improvement of the above method, the wind turbine blade recycling resin in step S1 is made from discarded wind turbine blades through mechanical processing such as cutting, crushing, grinding, screening, etc., and its main component is cured epoxy resin; the polyolefin in step S2 is one or two of PE and PP; the maleic anhydride grafted polyolefin in step S3 is one or two of MAPE and MAPP; the biomass fiber in step S3 is one or more of wood processing residue fibers, bamboo fibers, and straw fibers.

[0009] As a further improvement of the above method, in the granulation process in step S2, one or more ultrasonic devices are arranged on the barrel of the granulation device, and / or in the extrusion molding process in step S3, one or more ultrasonic devices are arranged on the barrel of the extrusion device.

[0010] As a further improvement of the above method, the step S2 of preparing the wind turbine blade recycled fiber reinforced polyolefin masterbatch comprises the following steps:

[0011] S2.1: Modify the recycled fiber from wind turbine blades by low-temperature plasma treatment to obtain material A;

[0012] S2.2: Anhydrous ethanol and distilled water are mixed to form solution B, and a silane coupling agent is added to solution B to prepare solution C;

[0013] S2.3: placing the material A in the solution C, allowing the material A to be immersed in the solution C, and undergoing an aging process;

[0014] S2.4: The material processed in step S2.3 is further placed in a drying device for drying to obtain material D;

[0015] S2.5: Modifying the material D by low temperature plasma treatment to obtain material E;

[0016] S2.6: dissolving DCP in an acetone solution to obtain a solution F;

[0017] S2.7: Spray the solution F into the material E and stir evenly to obtain material G;

[0018] S2.8: Dissolve DCP and MAH in acetone solution to obtain solution H;

[0019] S2.9: Spray the solution H into the polyolefin and stir evenly to obtain material I;

[0020] S2.10: The material G and the material I are granulated by a granulator to obtain a wind turbine blade recycled fiber reinforced polyolefin masterbatch.

[0021] As a further improvement of the above method, the wind turbine blade recycled fiber in step S2.1 is a mechanically processed recycling product of discarded wind turbine blades, and the mechanical processing includes one or more of a cutting step, a tearing step, an impact step, an extrusion step, a hammering step, a grinding step, and a screening step.

[0022] As a further improvement of the above method, the wind turbine blade recycled fiber in step S2.1 includes 60-90 parts by mass of glass fiber and 10-40 parts by mass of cured epoxy resin powder, and the epoxy resin powder is irregularly distributed and attached to the surface of the glass fiber.

[0023] As a further improvement of the above method, the silane coupling agent in step S2.2 is one or more silane coupling agents with amino functional groups or vinyl functional groups.

[0024] As a further improvement of the above method, the silane coupling agent is KH550 silane coupling agent and / or KH151 silane coupling agent.

[0025] As a further improvement of the above method, the mass ratio of DCP contained in the solution F of step S2.7 to the mass ratio of material E is less than 1:100; the mass ratio of DCP contained in the solution H of step S2.9 to polyolefin is in the range of 1:1000 to 1:100; the mass ratio of MAH contained in the solution H of step S2.9 to polyolefin is between 1:200 and 1:20.

[0026] The present invention also provides a technical solution for wind turbine blade recycled material reinforced wood-plastic composite material products, wherein the wood-plastic composite material products are prepared by any one of the methods in the above technical solutions.

[0027] As a further improvement of the above-mentioned product, the weight proportion of recycled resin in the raw materials of the product is 5-20 parts; the weight proportion of wind turbine blade recycled fiber reinforced polyolefin masterbatch is 5-30 parts; the weight proportion of polyolefin is 0-30 parts; the weight proportion of maleic anhydride grafted polyolefin is 3-15 parts; the weight proportion of biomass fiber is 20-60 parts; and the weight proportion of other additives is 2-20 parts.

[0028] The beneficial effects of the present invention are:

[0029] 1. In the recycling process of discarded wind turbine blades, two types of recyclables, recycled fiber and recycled resin, are mainly produced. However, it is very difficult to realize the industrialization and high-value utilization of these recyclables, and the mechanism of difficulty in recycling has not been fully revealed and disclosed by relevant academic research. At present, the effect of using glass fiber to reinforce wood-plastic is not obvious. One of the main reasons is that in the method of mixing glass fiber, biomass fiber, polyolefin and other materials and then granulating and extruding, due to the presence of biomass fiber, some glass fibers are not completely infiltrated with polyolefin, resulting in the influence of reinforcement performance. The present invention is based on the exploration and discovery of the inventor in the scientific research in the field of fiber reinforcement of wood-plastic composite materials. In order to give full play to the reinforcing effect of recycled fibers, the method of improving the existing preparation process of reinforcing masterbatch is used as a starting point. When preparing the reinforcing masterbatch, a better fiber dispersion technology is explored to ensure that the glass fiber can fully penetrate with polyolefin, thereby improving the reinforcement effect. Based on the research of the inventor, a new material formulation system has been developed to optimize the ratio and compatibility of glass fiber, biomass fiber and polyolefin and other materials, so that they can be better integrated together and play a complementary advantage. First, the recycled fibers from discarded wind turbine blades that are difficult to use are prepared into reinforcing masterbatches, which can be evenly dispersed in polyolefin resins, making better use of recycled fibers and recycled resins, and also helping to improve the overall performance and use value of wood-plastic composites. This has successfully solved the problem of the insignificant effect of recycled glass fiber reinforced wood-plastic composites from discarded wind turbine blades, and promoted the high-value application of discarded wind turbine blades.

[0030] 2. During the curing process of epoxy resin, due to the participation of a large number of active groups such as hydroxyl and epoxy groups in the reaction, the active groups of the cured epoxy resin are relatively few. In order to achieve a good interface bonding between the cured epoxy resin and the polyolefin, the present invention can increase a large number of active groups such as hydroxyl, carbonyl, and carboxyl groups on the surface of the epoxy resin attached to the recycled fiber by treating the recycled fiber with low-temperature plasma. These active groups can chemically react or hydrogen bond with silane coupling agents and maleic anhydride grafted polyolefins. At the same time, the surface of the epoxy resin will be etched to form grooves, thereby increasing the specific surface area and further improving the adhesion.

[0031] 3. In the wood plastic pelletizing process, the movement of the material is intensified by using ultrasonic vibration, thereby increasing the chance of microscopic contact. This allows the maleic anhydride groups in the reinforcing masterbatch to react more fully with the hydroxyl groups in the wood powder and recycled resin, thereby improving the interfacial compatibility between them and effectively improving the strength and performance of the wood plastic composite material. In addition, ultrasonic vibration also helps to disperse the recycled fibers and avoid agglomeration. Through the introduction of ultrasonic vibration, the movement of the material during the pelletizing process is more intense, and more contact occurs between the components, which improves the efficiency of the reaction. At the same time, ultrasonic vibration can also effectively solve the problem of dispersion of recycled fibers. Through the action of ultrasonic vibration, the agglomeration phenomenon that is easy to occur in the recycled fibers during the preparation process is avoided, the uniformity and quality of the material are improved, and the performance and availability of the material are further improved.

[0032] 4. Furthermore, after the granulation process, the active groups of each component of the wood-plastic are not 100% reacted. Therefore, the continued use of ultrasonic vibration in the wood-plastic extrusion process can further increase the reaction probability of the active groups, making the reaction more complete and the interface compatibility better. In addition, ultrasonic vibration is conducive to the dispersion of the recycled fibers and avoids the agglomeration of the recycled fibers under the action of the strong shear screw.

[0033] 5. In the process of recycling discarded wind turbine blades, some epoxy resins are peeled off from the surface of glass fibers after mechanical actions such as crushing and grinding. Although other epoxy resins adhere to the surface of glass fibers, the mechanical action leads to serious interface damage and connection weaknesses. These situations will greatly lead to more defects in the prepared composite materials, and their mechanical properties will decrease. The existing fiber recycling and reuse technology field still lacks effective methods to solve this problem. The present invention can effectively enhance the adhesion between the recycled fibers and the composite matrix, thereby improving the structural strength and durability of the composite material, helping to overcome the interface damage and connection weaknesses that occur during the recycling process, and helping to prepare a higher performance composite material.

[0034] 6. After the coupling agent KH550 and / or KH151 is used to treat the recycled fibers of discarded wind turbine blades in the present invention, the coupling agent will generate silanol during the hydrolysis process, and then react with the glass fiber of the recycled fiber and the hydroxyl groups on the surface of the cured epoxy resin to form a silicon-oxygen covalent bond. Through such treatment, on the one hand, the interface bonding between the glass fiber and the cured epoxy resin can be improved; on the other hand, the amino group in the KH550 silane coupling agent can react with the maleic anhydride group on the polyolefin molecular chain, and the vinyl group in the KH151 coupling agent can react with the polyolefin molecular chain under the action of DCP. These reactions can further improve the interface bonding between the glass fiber, the cured epoxy resin and the polyolefin, and improve the performance of the composite material.

[0035] 7. After being treated with the silane coupling agent, most of the hydroxyl groups of the epoxy resin on the recycled fiber have reacted with the silane coupling agent. In order to further improve the interfacial properties of the material, the present invention sets multiple low-temperature plasma treatment steps. Such treatment can introduce more active groups such as hydroxyl groups and carboxyl groups on the surface of the epoxy resin, thereby increasing the chance and probability of chemical reaction with maleic anhydride grafted polyolefin. Through this treatment method, the present invention can make the chemical reaction between the recycled fiber and the composite material matrix more sufficient, further increase the probability of chemical interaction between the recycled fiber and the polymer matrix, enhance its interfacial bonding ability, and improve the bonding strength and stability of the interface.

[0036] 8. In order to ensure that the vinyl group in KH151 can react chemically with polyolefin quickly, the present invention fully considers the problem of premature consumption of DCP in material I due to in-situ grafting reaction. By adding an appropriate amount of DCP to material E to generate more free radicals, the vinyl group in KH151 can be effectively combined with polyolefin. This measure can improve the reaction efficiency and increase the interface bonding of the product.

[0037] 9. The present invention grafts maleic anhydride groups onto the surface of polyolefin through an in-situ grafting reaction of DCP and MAH.

[0038] 10. It is generally believed that ultrasound has little effect on the preparation process of composite materials, but in the present invention, the ultrasonic device installed between the main feed port of the granulator and the side feeder can improve the chemical reaction process of polyolefins. Under the vibration of ultrasound, the free radical content is increased, which promotes the movement of polyolefin molecular chains. In this way, more maleic anhydride (MAH) can be successfully grafted onto the polyolefin molecular chain under the influence of the present invention, thereby improving the in-situ grafting rate.

[0039] 11. The present invention sets an ultrasonic device between the side feeder and the granulator die. Ultrasonic vibration increases the free radical content, accelerates the movement of the polyolefin molecular chain, makes the vinyl functional group on the KH151 coupling agent and the polyolefin have more covalent bonds, and the amino functional group of KH550 and the maleic anhydride group on the in-situ grafted polyolefin react with each other with higher probability, forming more amide covalent bonds, resulting in a significant increase in the reaction contact points of the epoxy resin, glass fiber and polyolefin molecular chain, thereby greatly improving the interfacial compatibility of the above three components. In addition, ultrasonic vibration helps disperse the glass fiber and reduce the probability of glass fiber agglomeration, so that the function of fiber-reinforced thermoplastic resin can be better exerted.

[0040] In summary, the active groups in the wind turbine blade recycled fibers are greatly increased through low-temperature plasma and silane coupling agent modification treatment. The interfacial compatibility of glass fiber, cured epoxy resin and polyolefin in the wind turbine blade recycled fibers is greatly improved through in-situ grafting modification and ultrasonic vibration, and the dispersibility of recycled fibers in polyolefin is improved, thereby preparing wind turbine blade recycled fiber reinforced polyolefin masterbatch, so that the recycled waste wind turbine blades can be used at a high value. By subjecting the wind turbine blade recycled resin to low-temperature plasma treatment and adding ultrasonic devices to the wood-plastic granulation and extrusion equipment, the mechanical properties of the wood-plastic composite material are greatly improved, the application field of wood-plastic is broadened, and the recycled waste wind turbine blades can be used at a high value. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention is a schematic flow chart of a method for preparing a wind turbine blade recycled material reinforced wood-plastic composite material. DETAILED DESCRIPTION

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the embodiments are briefly described below. Obviously, what is described is only a part of the embodiments of the present invention, not all of them, and those skilled in the art can also obtain other design solutions based on the flow chart without creative work.

[0043] A preparation method of wind turbine blade recycled material reinforced wood-plastic composite material, S1: modifying wind turbine blade recycled resin by low-temperature plasma treatment process using a low-temperature plasma treatment machine for powder to obtain modified wind turbine blade recycled resin; S2: compounding wind turbine blade recycled fiber with polyolefin, and obtaining wind turbine blade recycled fiber reinforced polyolefin masterbatch by granulation process; S3: mixing the modified wind turbine blade recycled resin obtained by step S1 and the wind turbine blade recycled fiber reinforced polyolefin masterbatch obtained by step S2 with polyolefin and / or maleic anhydride grafted polyolefin, biomass fiber and other additives, granulating, extruding and molding, to obtain waste wind turbine blade recycled fiber reinforced polyolefin-based wood-plastic composite material. The beneficial effect of this embodiment is that when epoxy resin is cured, a large number of active groups such as hydroxyl and epoxy groups participate in the reaction, so the active groups of the cured epoxy resin are relatively small. In order to allow the cured epoxy resin and polyolefin to form a good interface bonding, the recycled material is treated with low-temperature plasma, so that a large number of active groups such as hydroxyl groups are added to the surface of the cured epoxy resin, which can react chemically with silane coupling agents and maleic anhydride grafted polyolefins. At the same time, the surface of the cured epoxy resin is etched to form grooves, increasing the specific surface area and improving adhesion, thereby preparing higher performance wood-plastic composite materials.

[0044] As a further improvement of the above method, the wind turbine blade recycling resin in step S1 is made from waste wind turbine blades through mechanical processing such as cutting, crushing, grinding, screening, etc., and the main component is cured epoxy resin; the polyolefin in step S2 is one or both of PE and PP; the maleic anhydride grafted polyolefin in step S3 is one or both of MAPE and MAPP; the biomass fiber in step S3 is one or more of wood processing residue fiber, bamboo fiber, and straw fiber; the other additives in step S3 are one or more of antioxidants, anti-ultraviolet agents, calcium carbonate, talcum powder, pigments, and lubricants. The beneficial effects of this embodiment are: a new material formula system is developed to optimize the ratio and compatibility of glass fiber, biomass fiber, and polyolefin materials, so that they can be better integrated together and play a complementary advantage.

[0045] As a further improvement of the above method, in the granulation process in step S2, one or more ultrasonic devices are arranged on the barrel of the granulation device, or in the extrusion molding link in step S3, one or more ultrasonic devices are arranged on the barrel of the extrusion device. The beneficial effect of this embodiment is that after the ultrasonic device is arranged, the ultrasonic vibration increases the free radical content, accelerates the movement of the polyolefin molecular chain, makes more MAH grafted onto the polyolefin molecular chain, and improves the in-situ grafting rate. It can also prevent the DCP initiator of maleic anhydride and polyolefin materials from being consumed in advance, so as to better promote the decomposition of DCP in the recycled fiber and trigger the KH151 vinyl polyolefin reaction.

[0046] As a further improvement of the above method, the preparation of the wind turbine blade recycled fiber reinforced polyolefin masterbatch in the step S2 has the following steps: S2.1: modifying the wind turbine blade recycled fiber by a low-temperature plasma treatment process to obtain material A; S2.2: preparing anhydrous ethanol and distilled water into solution B, adding a silane coupling agent to solution B to obtain solution C; S2.3: placing the material A in the solution C, soaking the material A in the solution C, and subjecting the material A to an aging process; S2.4: further placing the material treated in step S3 in a drying device for drying to obtain Material D; S2.5: modify the material D by low temperature plasma treatment process to obtain material E; S2.6: dissolve DCP in acetone solution to obtain solution F; S2.7: spray the solution F in the material E, stir evenly, and obtain material G; S2.8: dissolve DCP and MAH in acetone solution to obtain solution H; S2.9: spray the solution H in polyolefin, stir evenly, and obtain material I; S2.10: granulate the material G and the material I by a granulator to obtain a wind turbine blade recycled fiber reinforced polyolefin masterbatch. The beneficial effect of this embodiment is: providing a more reasonable composite material manufacturing process, which is conducive to overcoming the defects of the existing technology that the cured epoxy resin powder and the glass fiber short fiber containing the cured epoxy resin are insufficient in performance when used to prepare composite materials, and can make the composite product performance better, and provide a wind turbine blade recycled fiber reinforced polyolefin masterbatch that can effectively utilize the wind turbine blade recycled fiber, thereby promoting the smooth preparation of high-performance wood-plastic composite materials.

[0047] As a further improvement of the above method, the wind turbine blade recycled fiber in step S2.1 is a mechanical processing recycling product of waste wind turbine blades, and the mechanical processing includes a cutting step, a tearing step, an impact step, an extrusion step, a hammering step, a grinding step and a screening step. The beneficial effect of this embodiment is that through the mechanical processing of the above steps, the recyclables of the wind turbine blades can be fully decomposed into a resin part and a fiber part, which is more conducive to the efficient utilization and production of high-quality wood-plastic composite materials.

[0048] As a further improvement of the above method, the silane coupling agent in step S2.2 is one or more of the silane coupling agents with amino functional groups or vinyl functional groups, and the preferred silane coupling agent is KH550 silane coupling agent and / or KH151 silane coupling agent. The beneficial effect of this embodiment is that in the process of recycling discarded wind turbine blades, after mechanical actions such as crushing and grinding, part of the epoxy resin peels off from the surface of the glass fiber, and although part of the epoxy resin is bonded to the surface of the glass fiber, the mechanical action causes serious damage to the interface between the epoxy resin and the glass fiber, and there are many connection weaknesses. This will lead to an increase in defects in the prepared composite material and a decrease in mechanical properties. After the recycled fiber is treated with a silane coupling agent, most of the hydroxyl groups of the epoxy resin on it react with the silane coupling agent. The low-temperature plasma treatment again is to increase active groups such as hydroxyl groups and carboxyl groups on the surface of the epoxy resin, thereby increasing the probability of chemical reaction with maleic anhydride grafted polyolefin. KH550 and KH151 coupling agents are hydrolyzed into silanols, which react with the hydroxyl groups on the surface of glass fiber and epoxy resin of recycled fibers from discarded wind turbine blades to form silicon-oxygen covalent bonds. On the one hand, this can improve the interfacial bonding between glass fiber and epoxy resin. On the other hand, the amino group of KH550 silane coupling agent can react with the maleic anhydride group on the polyolefin molecular chain, and the vinyl group of KH151 coupling agent can react with polyolefin, thereby improving the interfacial bonding between glass fiber, epoxy resin and polyolefin.

[0049] As a further improvement of the above method, the mass fraction of DCP in the material E in step S2.7 is 0.1%-1%. The beneficial effect of this embodiment is that the material I first undergoes an in-situ grafting reaction, and the DCP in the material I may be consumed prematurely, while DCP is added to the material E to generate free radicals, which can ensure that the vinyl group of KH151 can react chemically with the polyolefin.

[0050] As a further improvement of the above method, the mass fraction of DCP in the solution H of step S2.9 is 0.1%-1% of the polyolefin, and the mass fraction of MAH in the polyolefin is 0.5%-5%, and the polyolefin is one or both of PE and PP. The beneficial effect of this embodiment is that maleic anhydride groups are grafted on the surface of the polyolefin through the in-situ grafting reaction of DCP and MAH.

[0051] A wind turbine blade recycled material reinforced wood-plastic composite material product is produced by any of the above methods, wherein the weight proportion of the recycled resin in the product raw material is 5-20 parts; the weight proportion of the wind turbine blade recycled fiber reinforced polyolefin masterbatch is 5-30 parts; the weight proportion of the polyolefin is 0-30 parts; the weight proportion of the maleic anhydride grafted polyolefin is 3-15 parts; the weight proportion of the biomass fiber is 20-60 parts; and the weight proportion of other additives is 2-20 parts.

[0052] The invention uses low-temperature plasma and silane coupling agent modification treatment to greatly increase the active groups in the wind turbine blade recycled fiber, and through in-situ grafting modification and ultrasonic vibration, greatly improves the interfacial compatibility of glass fiber, cured epoxy resin and polyolefin in the wind turbine blade recycled fiber, improves the dispersibility of the recycled fiber in polyolefin, and thus prepares the wind turbine blade recycled fiber reinforced polyolefin masterbatch. By subjecting the wind turbine blade recycled resin to low-temperature plasma treatment and adding an ultrasonic device to the wood-plastic granulation and extrusion equipment, the mechanical properties of the wood-plastic composite material are greatly improved, the application field of the wood-plastic is broadened, and the recycled waste wind turbine blades can be used at a high value.

Claims

1. A method for preparing a wind turbine blade recycled material reinforced wood-plastic composite material, characterized in that: The steps are as follows: S1: modifying the wind turbine blade recycled resin by a low-temperature plasma treatment process using a low-temperature plasma treatment machine to obtain a modified wind turbine blade recycled resin; S2: Compounding the wind turbine blade recycled fiber with polyolefin, and preparing the wind turbine blade recycled fiber reinforced polyolefin masterbatch through a granulation process; S3: the modified wind turbine blade recycled resin obtained in step S1 and the wind turbine blade recycled fiber reinforced polyolefin masterbatch obtained in step S2 are mixed with polyolefin and / or maleic anhydride grafted polyolefin and biomass fiber, and one or more of an antioxidant, an anti-aging agent, an anti-ultraviolet agent, calcium carbonate, a lubricant and a pigment are added and mixed, and the waste wind turbine blade recycled fiber reinforced polyolefin-based wood-plastic composite material is obtained by granulation and extrusion molding; The wind turbine blade recycling resin in step S1 is obtained by cutting, crushing, grinding and screening the waste wind turbine blades, and the main component is cured epoxy resin; the polyolefin in step S2 is one or two of PE and PP; the maleic anhydride grafted polyolefin in step S3 is one or two of MAPE and MAPP; the biomass fiber in step S3 is one or more of wood processing residue fiber, bamboo fiber and straw fiber; The step S2 of preparing the wind turbine blade recycled fiber reinforced polyolefin masterbatch comprises the following steps: S2.1: Modify the recycled fiber from wind turbine blades by low-temperature plasma treatment to obtain material A; S2.2: Anhydrous ethanol and distilled water are mixed to form solution B, and a silane coupling agent is added to solution B to prepare solution C; S2.3: placing the material A in the solution C, allowing the material A to be immersed in the solution C, and undergoing an aging process; S2.4: The material processed in step S2.3 is further placed in a drying device for drying to obtain material D; S2.5: Modifying the material D by low temperature plasma treatment to obtain material E; S2.6: dissolving DCP in an acetone solution to obtain a solution F; S2.7: Spray the solution F into the material E and stir evenly to obtain material G; S2.8: Dissolve DCP and MAH in acetone solution to obtain solution H; S2.9: Spray the solution H into the polyolefin and stir evenly to obtain material I; S2.10: Granulate the material G and the material I with a granulator to obtain a wind turbine blade recycled fiber reinforced polyolefin masterbatch; The wind turbine blade recycled fiber in step S2.1 comprises 60-90 parts by mass of glass fiber and 10-40 parts by mass of cured epoxy resin powder, and the epoxy resin powder is irregularly distributed and attached to the surface of the glass fiber; The mass ratio of DCP contained in the solution F of step S2.7 to the mass ratio of material E is less than 1:100; the mass ratio of DCP contained in the solution H of step S2.9 to polyolefin is in the range of 1:1000 to 1:100; the mass ratio of MAH contained in the solution H of step S2.9 to polyolefin is between 1:200 and 1:

20.

2. The method for preparing a wind turbine blade recycled material reinforced wood-plastic composite material according to claim 1, characterized in that: In the granulation process in step S2, one or more ultrasonic devices are arranged on the barrel of the granulation device, and / or in the extrusion molding process in step S3, one or more ultrasonic devices are arranged on the barrel of the extrusion device.

3. The method for preparing a wind turbine blade recycled material reinforced wood-plastic composite material according to claim 1, characterized in that: The wind turbine blade recycled fiber in step S2.1 is a mechanically processed recycling product of discarded wind turbine blades, and the mechanical processing includes one or more of a cutting step, a tearing step, an impact step, an extrusion step, a hammering step, a grinding step and a screening step.

4. The method for preparing a wind turbine blade recycled material reinforced wood-plastic composite material according to claim 1, characterized in that: The silane coupling agent in step S2.2 is one or more silane coupling agents with amino functional groups or vinyl functional groups.

5. The method for preparing a wind turbine blade recycled material reinforced wood-plastic composite material according to claim 4, characterized in that: The silane coupling agent is KH550 silane coupling agent and / or KH151 silane coupling agent.

6. A wind turbine blade recycled material reinforced wood-plastic composite material product, characterized in that: The method described in any one of claims 1 to 5 is adopted, and the weight proportion of the recycled resin in the product raw material is 5-20 parts; the weight proportion of the wind turbine blade recycled fiber reinforced polyolefin masterbatch is: 5-30 parts; the weight proportion of polyolefin is: 0-30 parts; the weight proportion of maleic anhydride grafted polyolefin is: 3-15 parts; the weight proportion of biomass fiber is: 20-60 parts.

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