Recycled fiber-reinforced resin, recycled resin composition, recycled resin molded body, and method for producing same

Abstract

The present invention solves the problems in the recycling of a dismantled windmill blade and provides a recycling system of a dismantled windmill blade. A method for producing a recycled fiber-reinforced resin comprises: a cutting step S1 for cutting a waste plastic material, derived from at least one kind selected from a windmill blade, a bathtub and a hull and containing a fiber-reinforced resin, into substantially plate-shaped members of a size in a range from a 50 cm square to a 1 m square at a dismantling site of the waste plastic material; a shredding step S2 for transporting the substantially plate-shaped members to a resin manufacturing plant and pulverizing the substantially plate-shaped members in the manufacturing plant; and steps S4 and S5 for kneading and molding the recycled fiber-reinforced resin and a thermoplastic resin. The shredding step S2 is a step for pulverizing the substantially plate-shaped members in a plurality of stages to obtain a pulverized matter having a final average particle diameter between 10 μm and 50 μm both inclusive.

Description

Recycled fiber reinforced resin, recycled resin composition, recycled resin molded body, and methods for producing these

[0001] The present invention relates to a recycled fiber reinforced resin, a recycled resin composition, a recycled resin molded product, and methods for producing these.

[0002] Fiber-reinforced plastics (FRP) are composite materials in which reinforcing fibers such as glass fiber or carbon fiber are dispersed in unsaturated polyester resin or epoxy resin, significantly improving the specific strength and specific modulus of elasticity. Among FRPs, glass fiber-reinforced plastics (GFRP) in particular have high mechanical properties and chemical stability, are inexpensive, are lighter than metal materials, and can be mass-produced. For this reason, GFRP is widely used in bathtubs, boat hulls, and other applications.

[0003] However, the high chemical stability of GFRP is both an advantage and a disadvantage. The unsaturated polyester resin and epoxy resin that make up GFRP are types of thermosetting resins, and irreversibly form a three-dimensional structure accompanied by a crosslinking reaction during molding. Once the three-dimensional structure is formed, it can no longer be returned to its original liquid state by normal heating or solvent treatment. Therefore, GFRP that has reached the end of its lifespan is difficult to recycle, and in reality it is incinerated and landfilled as industrial waste.

[0004] However, in light of the recent trend toward environmental protection, including the Sustainable Development Goals (SDGs), research into the recycling of GFRP is progressing. GFRP recycling is being studied from the perspectives of material recycling and chemical recycling.

[0005] Material recycling involves physically and mechanically processing discarded materials and using them as additives for other materials. One practical example is a method in which waste GFRP is finely pulverized and reused as a cement filler. It has also been proposed to use finely pulverized thermosetting waste plastic (waste FRP) as a filler for thermoplastic waste plastic (polypropylene, PP) to create pellets for injection molding, which can then be used as a plastic material for injection molding (Non-Patent Document 1).

[0006] Chemical recycling is a method of chemically treating waste GFRP materials to break down the unsaturated polyester resin into its raw materials, which are then broken down into smaller molecules and liquefied, allowing the glass fiber reinforcement to be separated and recovered, and the resin raw material and the separated glass fiber to be reused as raw materials for GFRP.However, high processing costs remain an issue, and although research is progressing, chemical recycling has not yet become as widespread as material recycling.

[0007] Sato et al., Development of Recycling Technology for Waste FRP and Its Applications, Research Report for 1995, Oita Prefectural Industrial Science and Technology Center

[0008] In addition to bathtub and ship hull materials, FRP is also used for wind turbine blades used in wind power plants. However, wind turbine blades have a diameter of approximately 80 meters and weigh approximately 5 tons each. In addition, wind power generation is generally carried out in remote locations. This requires optimization in terms of both dismantling costs and transportation costs from the dismantling site to the material recycling plant. In this respect, recycling wind turbine blades is even more difficult than recycling bathtub and ship hull materials. To realize a recycling system for dismantled wind turbine blades, existing regeneration technologies alone are insufficient; issues must be addressed in terms of dismantling efficiency.

[0009] Furthermore, dismantled wind turbine blades contain not only FRP but also wood chips. Therefore, the wood chips contained in dismantled wind turbine blades can be an obstacle when it comes to reusing them as cement filler. From an efficiency standpoint, it is better not to have to remove the wood chips, so there is a need to develop applications that do not require the removal of wood chips.

[0010] In Japan, a total of 2,626 wind power plants have been built since 1995, with a cumulative total of 2,626 in operation (as of December 2022). Meanwhile, 72 wind turbines, which have reached the end of their 20-year lifespan, will be dismantled and removed in 2023, and thereafter this number will increase to 100-200 per year. Until now, each turbine has used three wind turbine blades, meaning that each turbine blade weighs approximately 15 tons, and it is estimated that 1,500 tons of wind turbine blades will be disposed of annually in Japan alone.

[0011] The European Union (EU) generated 510 TWh of wind power in 2020, 65 times the amount generated by Japan. In addition, offshore wind power generation, which generates electricity using giant wind turbines installed on the sea, is progressing, and construction of wind power plants is underway, mainly in the North Sea.

[0012] Therefore, providing a recycling system for dismantled wind turbine blades is an urgent issue.

[0013] The present invention has been made in consideration of the above circumstances, and its purpose is to solve the problems involved in recycling dismantled wind turbine blades and to realize a recycling system for dismantled wind turbine blades.

[0014] The inventors discovered that by cutting dismantled wind turbine blades to predetermined dimensions at the wind turbine dismantling site, then transporting the cut pieces to a recycled resin manufacturing site and crushing them at the manufacturing site, it is possible to obtain recycled fiber-reinforced resin with an average particle size of 10 μm to 50 μm. This solved both the issues of the weight of wind turbine blades and the transportation from the wind power generation site to the factory, and led to the completion of the present invention. Specifically, the present invention provides the following.

[0015] The present invention is a method for producing recycled fiber-reinforced resin, which includes a cutting step in which waste plastic material derived from at least one or more types selected from wind turbine blades, bathtubs, and ship hulls and containing fiber-reinforced resin is cut into approximately plate-shaped members ranging from 50 cm square to 1 m square at a waste plastic material dismantling site, and a crushing step in which the approximately plate-shaped members are transported to a resin manufacturing plant and crushed at the manufacturing plant, wherein the crushing step is a step in which the approximately plate-shaped members are crushed in multiple stages so that the final average particle size of the crushed material is 10 μm or more and 50 μm or less.

[0016] According to the present invention, waste plastic materials are cut into approximately plate-shaped members of 1 m square or less at the demolition site, which allows them to be loaded onto vehicles and transported in terms of both size and weight, reducing transportation costs from the demolition site to the material recycling plant. Furthermore, because the size of the approximately plate-shaped members is 50 cm square or more, the crushed blades can be quickly removed from the demolition site, preventing unnecessary extension of the construction period and reducing demolition costs. This makes it possible to optimize both demolition costs and transportation costs from the demolition site to the material recycling plant.

[0017] Therefore, according to the present invention, the issues of the weight of wind turbine blades and the transportation from the wind power generation site to the factory can be solved at once, making it possible to realize a recycling system for dismantled wind turbine blades.

[0018] In addition, in the present invention, it is preferable that the crushing step includes a first crushing step of crushing the approximately plate-shaped member so that the average particle diameter is 20 mm or more and 60 mm or less, a second crushing step of crushing the crushed material after the first crushing step so that the average particle diameter is 10 mm or more and 50 mm or less, and a crushing step of crushing the crushed material after the second crushing step so that the average particle diameter is 10 μm or more and 50 μm or less.

[0019] According to the present invention, cut pieces having a stable three-dimensional structure are crushed in multiple stages, so that damage to the crushing device can be suppressed.

[0020] The present invention also relates to a method for producing a recycled resin composition, which includes a kneading and molding step using an extruder or a compressor after kneading a kneading target containing at least 20% by mass to 30% by mass of the recycled fiber-reinforced resin and 65% by mass to 78% by mass of a plastic resin. The present invention also relates to a method for producing a recycled resin composition, which includes a kneading and molding step using an extruder after kneading a kneading target containing at least 20% by mass to 30% by mass of the recycled fiber-reinforced resin and 65% by mass to 78% by mass of a plastic resin. In this method, it is preferable that the plastic resin contains at least one resin selected from the group consisting of a wind power plant, a bathroom, and a ship.

[0021] Recycled fiber reinforced resin has the drawback of being too hard and difficult to recycle. However, according to the present invention, by mixing recycled fiber reinforced resin with plastic resin, it becomes possible to knead the resin uniformly using an extruder, thereby solving the problem that FRP is too hard to recycle.

[0022] The present invention also provides a method for producing a recycled resin composition, wherein the material to be kneaded contains a virgin thermoplastic resin produced from raw materials.

[0023] By mixing virgin thermoplastic resin produced from raw materials with recycled fiber reinforced resin and plastic resin, the thermoplasticity can be further enhanced, making it easier to knead uniformly using an extruder, and solving the problem of FRP being too hard and difficult to recycle.In addition, since the object of the present invention is to effectively utilize used FRP to produce thermoplastic resin molded products into inexpensive recycled fiber reinforced resin, the material to be kneaded can be either virgin or recycled, as long as it is thermoplastic resin.

[0024] The fiber-reinforced resin derived from at least one material selected from wind turbine blades, bathtubs, and ship hulls contains at least one impurity component selected from wood components, corrosion-preventing paint components, urethane components, and rubber components. According to the present invention, the recycled fiber-reinforced resin functions as a filler for plastic resins, and therefore, unlike when recycled fiber-reinforced resin is reused as a cement filler, even if a small amount of impurity component is contained, it does not affect the recycled resin composition.

[0025] In addition, recycled fiber-reinforced resins have high strength, which can increase the strength of recycled resin compositions, thereby adding value to the mixture. Furthermore, when waste plastic materials are derived from wind turbines, recycled fiber-reinforced resins contain wood components, which has the advantage of reducing the amount of plastic resin used by including wood components in the filler. Therefore, wood components, which would otherwise be impurities, can be used to their full potential. Similarly, recycled fiber-reinforced resins can also have the advantage of reducing the amount of plastic resin used, even when they contain urethane or rubber components.

[0026] Therefore, according to the present invention, a recycling system for dismantled wind turbine blades can be realized.

[0027] According to the present invention, the problems involved in recycling dismantled wind turbine blades can be solved, and a recycling system for dismantled wind turbine blades can be realized.

[0028] Fig. 1 is a flowchart showing a method for manufacturing recycled fiber reinforced resin, recycled resin composition, and resin molded body. Fig. 2 is a side layout diagram of the manufacturing system. Fig. 3 is a plan layout diagram of the manufacturing system. Fig. 4 is an explanatory diagram of the cutting device. Fig. 5 is a right side view of the cutting mechanism. Fig. 6 is a front view of the cutting mechanism. Fig. 7 is a bottom view of the cutting mechanism. Fig. 8 is an explanatory diagram of the cutting device. Fig. 9 is an explanatory diagram showing the schematic configuration of a powder polishing and sorting device. Fig. 10 is an explanatory diagram of the crushing mechanism.

[0029] An example of a preferred embodiment for carrying out the present invention will be described below. However, this is merely an example, and the technical scope of the present invention is not limited to this example.

[0030] (Method for manufacturing recycled fiber reinforced resin) As shown in FIG. 1, the method for manufacturing recycled fiber reinforced resin of this embodiment includes a cutting step S1 in which waste plastic material containing fiber reinforced resin and which is difficult to transport while maintaining its original shape is cut into approximately plate-shaped members ranging from 50 cm square to 1 m square at a waste plastic material dismantling site, and a crushing step S2 in which the approximately plate-shaped members are transported to a resin manufacturing plant and crushed at the manufacturing plant to reduce the average particle diameter to 10 μm or more and 50 μm or less.

[0031] Here, "fiber-reinforced resin" refers to a composite material of fiber and resin. Examples of fibers include glass fiber, carbon fiber, aramid fiber, and Kevlar® fiber. Examples of resins include epoxy resin, polyester resin, and phenolic resin. Therefore, the method for producing recycled fiber-reinforced resin according to this embodiment is a method for recycling both fiber-reinforced resins (G-FRP, Glass-Fiber Reinforced Plastic) and carbon-fiber-reinforced resins (C-FRP), as well as all waste materials made from these materials. "Difficult to transport while maintaining the original shape" means that special transportation means are required to transport the waste plastic material while maintaining its original shape due to factors such as its weight and size. Special transportation means refer to large transportation equipment such as large trucks and ships. The "waste plastic material" preferably contains fiber-reinforced resin derived from at least one material selected from wind turbine blades, bathtubs, and ship hulls. However, the material is not particularly limited as long as it is a component formed from fiber-reinforced resin. For example, the object may be a wind turbine blade, a bathtub, a ship body, an automobile part, an aircraft part, a construction material, a civil engineering material, a sporting goods, or the like.

[0032] In the cutting step S1, the waste plastic material is cut into approximately plate-shaped pieces of 1 m square or less at the demolition site because they can be loaded onto a vehicle and transported in terms of both size and weight, reducing transportation costs from the demolition site to the material recycling plant. Furthermore, the size of the approximately plate-shaped pieces is such that they can be directly fed into the plant's shredding machine. The reason the size of the approximately plate-shaped pieces is 50 cm square or more is because the crushed blades can be quickly removed from the demolition site, preventing unnecessary lengthening of the construction period and reducing demolition costs. Therefore, when the waste plastic material is cut into approximately plate-shaped pieces of 50 cm square to 1 m square at the demolition site, it is possible to optimize both the demolition cost and the transportation cost from the demolition site to the material recycling plant.

[0033] This solves the problems of the weight of wind turbine blades and the transportation of the blades from the wind power generation site to the factory at once, making it easy to realize a recycling system for dismantled wind turbine blades. In other words, a recycling system for waste plastic materials that would normally require special transportation means due to their weight and size can now be easily realized using ordinary transportation means. Note that ordinary transportation means refers to transportation using small transportation equipment such as small / medium-sized trucks and vans.

[0034] In the crushing step S2, the waste plastic material in the approximately plate-shaped components ranging from 50 cm square to 1 m square may be crushed all at once until the average particle size is 10 μm to 50 μm, or it may be crushed gradually in multiple stages. The reason for this is that crushing the waste plastic material, which is a cut piece having a stable three-dimensional structure, in multiple stages reduces the load on the crushing device in each stage, thereby suppressing damage to the crushing device.

[0035] For example, the crushing step S2 includes a first crushing step S21 in which the approximately plate-shaped member is crushed to an average particle diameter of 20 mm or more and 60 mm or less, and a second crushing step S22 in which the crushed material after the first crushing step S21 is crushed to an average particle diameter of 10 mm or more and 50 mm or less.

[0036] As shown in FIG. 2 , the first crushing step S21 is a step of roughly crushing the waste plastic material, breaking down the waste plastic material from large chunks into small pieces, and efficiently performing the subsequent second crushing step S22. Examples of the rough crusher 12 used in the first crushing step S21 include a cutter mill, a roller mill, a hammer mill, a jaw crusher, and a shredder. A cutter mill is configured to cut the waste plastic material using a rotating cutter. A roller mill is configured to compress and crush the waste plastic material using a rotating roller. A hammer mill is configured to crush the waste plastic material using a rotating hammer. A jaw crusher has two plates: a fixed "fixed jaw" on one side and a vibrating "moving jaw" on the other side. The moving jaw is swung up and down using an eccentric shaft or link mechanism, compressing and crushing the waste plastic material between the fixed jaw and the moving jaw. A shredder is a crushing device that consists of a rotating drum or disc equipped with a series of blades or hammers, and the high-speed rotating blades or hammers shred the material.

[0037] The second crushing step S22 is a step of finely crushing the waste plastic material, reducing the particles of the waste plastic material to even smaller sizes than those crushed in the first crushing step S21, and further dispersing the fibers, resins, and metals contained within the waste plastic material through fine crushing. Examples of fine crushers 13 used in the second crushing step S22 include cutter mills, ball mills, convergence mills, rod mills, and disc mills. Cutter mills have a similar configuration to coarse crushing. Ball mills are configured to fill a rotating cylinder with media such as balls or beads, and crush the waste plastic material using the media. Converge mills are configured to place a screw inside a rotating cylinder and crush the waste plastic material using the screw. Rod mills are configured to have steel rods arranged horizontally inside a cylindrical drum, and the rods rise as the drum rotates, and then fall due to gravity, crushing the waste plastic material through the impact and friction generated when the rods fall. A disc mill is configured with two disks arranged facing each other, one of which is fixed and rotates relative to the other, to pulverize waste plastic material placed between the disks.

[0038] The method for producing recycled fiber reinforced resin includes a powdering process S3 that follows the crushing process S2. The powdering process S3 is a process for powdering the material crushed in the crushing process S2 and selecting desired components, such as separating plastics from metals. Specifically, the powdering process S3 includes a crushing process S31, a specific gravity sorting process S32, a powder polishing sorting process S33, and an electrostatic sorting process S34.

[0039] The pulverization step S31 is a step of finely pulverizing the waste plastic material into fine particles with an average particle diameter of 10 μm to 50 μm. Examples of the pulverization device 13 used in the pulverization step S31 include a ball mill, a bead mill, and a jet mill. A ball mill or a bead mill is configured to fill a rotating cylinder with media such as balls or beads, and pulverize the waste plastic material using the media. A jet mill is configured to pulverize the waste plastic material by using a high-speed airflow (compressed air or steam) to collide and grind the waste plastic material.

[0040] The gravity sorting step S32 is a step of separating waste plastic materials by utilizing differences in their specific gravities. For example, since the specific gravities of different types of plastic materials and metals differ, the gravity sorting machine 16 in the gravity sorting step S32 can be used to separate plastic materials by type, or to separate plastic materials from metals.

[0041] The powder polishing and sorting process S33 further pulverizes the pulverized material from the pulverization process S31 by cutting and abrasion in the powder polishing and sorting device 17, separating the pulverized material from other pulverized materials. This process improves the precision of the pulverization and the separation of the fibers and resin. This improves the mixability of the pulverized fiber-reinforced resin with the thermoplastic resin, such as a plastic resin or a virgin thermoplastic resin, when the pulverized fiber-reinforced resin is mixed with the thermoplastic resin for hot molding, thereby improving the physical properties of the molded product, particularly its strength and durability. Furthermore, the uniform particle size and uniform mixing improve the filling ability, uniform thermal conductivity, and fluidity during hot molding, reducing shrinkage and distortion, thereby improving the appearance and dimensional accuracy of the molded product.

[0042] The electrostatic separation process S34 is a process for separating waste plastic materials by utilizing differences in the electrical properties of the types of plastic materials and metals. For example, since the electrical properties differ depending on the type of plastic material and the type of metal, the electrostatic separation process S34 makes it possible to separate plastic materials by type or to separate plastic materials from metals.

[0043] As shown in FIG. 3 , the crushing step S31 may be parallelized to improve processing capacity. In this case, if the process required for fine crushing in the second crushing step S22 is completed in a shorter time than the process required for fine crushing in the crushing step S31, the finely crushed material can be continuously flowed to the parallel crushing steps S31, which have increased processing capacity, without having to be temporarily stored elsewhere as work-in-progress. The second crushing step S22 and the crushing step S31 may also be parallelized. In this case, if the process required for coarse crushing in the first crushing step S21 is completed in a shorter time than the process required for fine crushing and fine crushing in the second crushing step S22 and the crushing step S31, the coarsely crushed material can be continuously flowed to the parallel crushing steps S22 and the crushing step S31, without having to be temporarily stored elsewhere as work-in-progress.

[0044] (Method for Producing Recycled Resin Composition) As shown in FIG. 1, the recycled fiber reinforced resin production steps (S1, S2, and S3) are followed by a kneading step S4, which is a recycled resin composition production step. The kneading step S4 is a step of kneading, using an extruder, a mixture containing at least 20% to 30% by mass of recycled fiber reinforced resin obtained in the cutting step S1 and the crushing step S2, and 65% to 78% by mass of plastic resin. According to the kneading step S4, recycled fiber reinforced resin has the disadvantage of being too hard to recycle. However, by mixing the recycled fiber reinforced resin with plastic resin to produce a recycled resin composition, it is possible to uniformly knead the mixture using an extruder, thereby solving the problem of FRP being too hard to recycle.

[0045] "Plastic resin" refers to a thermoplastic resin recovered from used plastics, which softens when heated and hardens when cooled. Specific examples of general-purpose plastics include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), and polycarbonate (PC). Examples of engineering plastics include polyamide (PA), polyester (PET), polycarbonate (PC), polyphenyl ether (PPE), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE).

[0046] The plastic resin can be, for example, used plastics contained in containers and packaging, building materials, fibers, toys, and automobile parts. The plastic resin preferably includes a resin used to cover discarded electric wires used in at least one selected from wind power plants, bathrooms, and ship interiors. In this case, the recycled resin composition obtained by mixing recycled fiber-reinforced resin and plastic resin is derived from at least one selected from wind turbine blades, bathtubs, and ship hulls, and therefore contains at least one impurity component selected from wood components, corrosion-preventing paint components, urethane components, and rubber components. As a result, the recycled resin composition functions as a filler for the plastic resin. Therefore, unlike when recycled fiber-reinforced resin is reused as a cement filler, even if a small amount of impurities are contained, the recycled resin composition is not affected.

[0047] In addition, because recycled resin compositions have high strength, they can increase the strength of recycled resin molded bodies, thereby adding value to the mixture of recycled resin compositions. Furthermore, when waste plastic materials are derived from wind turbines, recycled fiber-reinforced resins contain wood components, which has the advantage of reducing the amount of plastic resin used by including wood components in the filler. Therefore, the wood components, which were originally impurities, can be used to their full potential. Similarly, even when recycled fiber-reinforced resins contain urethane or rubber components, they can also have the advantage of reducing the amount of plastic resin used.

[0048] Furthermore, the materials to be kneaded in the kneading step S4 may include recycled fiber-reinforced resin, plastic resin, and virgin thermoplastic resin. Here, "virgin thermoplastic resin" refers to a thermoplastic resin made from new raw materials that is not recycled. Virgin thermoplastic resin has a higher purity than plastic resin and is free of other materials or impurities, resulting in consistent quality. Virgin thermoplastic resin also has clear physical and chemical properties, making its performance easy to predict, and its behavior during the manufacturing process is stable and easy to process. Therefore, when virgin thermoplastic resin is mixed with recycled fiber-reinforced resin and plastic resin, the thermoplasticity can be further enhanced, making it easier to uniformly knead using an extruder, thereby solving the problem of FRP being too hard and difficult to recycle.

[0049] Virgin thermoplastic resins are resins that, like plastic resins, soften when heated and harden when cooled. Specific examples of general-purpose plastics include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), and polycarbonate (PC). Examples of engineering plastics include polyamide (PA), polyester (PET), polycarbonate (PC), polyphenyl ether (PPE), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE).

[0050] (Method for manufacturing recycled resin molded body) Following the kneading step S4 for producing the recycled resin composition, a molding step S5 for molding the recycled resin composition is provided. In the molding step S5, the mixed recycled resin composition is heated to a temperature at which the plastic resin softens, and then placed in a molding machine and molded into the desired shape by a method such as press molding, injection molding, or extrusion molding. The molded product is then cooled to harden the plastic resin and maintain its shape. After this, post-processing such as trimming, polishing, and painting is performed as necessary to produce the final molded product.

[0051] (Recycled Fiber Reinforced Resin Manufacturing System 1) As shown in Figures 2 and 3, the crushing step S2 and the sorting step S3 are provided in a recycled fiber reinforced resin and resin composition manufacturing system 1. The manufacturing system 1 has a first conveyor 111 on which cut pieces of waste plastic material transported from a dismantling site of the waste plastic material in the cutting step S1 are placed, and a rough crusher 12 for a first crushing step S21 connected to the discharge end of the first conveyor 111. The rough crusher 12 has a shredder mechanism and is configured to crush the cut pieces of the waste plastic material from large chunks of about 50 cm to 100 cm square to small pieces of about 20 mm to 40 mm square.

[0052] The inlet end of the second conveyor 112 is disposed below the coarse crusher 12 so as to receive the crushed pieces. The outlet end of the second conveyor 112 is connected to the fine crusher 13 of the second crushing process S22. The fine crusher 13 has a cutter mill mechanism and is configured to crush the waste plastic material into pieces of approximately 10 mm to 30 mm square, which are even smaller than the crushed pieces of the first crushing process S21. The inlet end of the third conveyor 113 is disposed below the fine crusher 13 so as to receive the crushed pieces. The outlet end of the third conveyor 113 is connected to a cash silo 14. The cash silo 14 is configured to temporarily store the crushed material transported from the fine crusher 13 and to discharge the stored crushed material from two outlets formed at both ends of the width of the production line.

[0053] The inlet portions of a pair of bucket conveyors 114 are connected to each discharge outlet of the cash silo 14. The discharge ends of the bucket conveyors 114 are connected to crushers 15 in the crushing process S31. The crushers 15 are configured to crush crushed material of approximately 10 mm to 30 mm square into crushed material of approximately 30 μm to 50 μm. The crushers 15 are connected to specific gravity sorters 16 in the specific gravity sorting process S32 via first pneumatic conveyors 115, which separate resins and metals. The specific gravity sorters 16 are connected to powder polishing and sorting devices 17 in the powder polishing and sorting process S33. The powder polishing and sorting devices 17 are configured to crush and sort the crushed material into crushed material of approximately 20 μm to 30 μm. The powder polishing and sorting devices 17 are connected to electrostatic separators 18 in the electrostatic sorting step S34 via screw conveyors 117. The electrostatic separators 18 are configured to charge the pulverized materials after sorting, subject the charged materials to an electric field, and separate pulverized materials having different charges.

[0054] In addition, exhaust ducts 116 are connected to the gravity separators 16, the powder polishing and separating devices 17, and the electrostatic separators 18. The exhaust ducts 116 are connected to a dust collector (not shown) and send out to the dust collector fine dust particles that are scattered during crushing and separating.

[0055] Next, a detailed description will be given of the main equipment used in the manufacturing system 1. (Cutting process S1: cutting device 2) As shown in Fig. 4, the cutting device 2 includes a hydraulic excavator 20 having a shovel body 23 moved by traveling crawlers 24 and an arm 22 attached to the shovel body 23, a cutting mechanism 21 detachably attached to the tip of the arm 22 and cutting the waste plastic material to a predetermined size, a water spray mechanism 25 that sprays water onto the cutting mechanism 21, and a water supply mechanism 26 attached to the shovel body 23 and supplying water to the water spray mechanism 25. The cutting mechanism 21 is provided at a predetermined separation width and includes a plurality of cutting blades 211 that cut the waste plastic material, and a drive mechanism 212 that hydraulically drives and rotates the cutting blades 211.

[0056] According to the above configuration, by using hydraulic pressure as the driving force for the cutting mechanism 21, it is possible to stably cut hard FRP, and by spraying water onto the cutting area, it is possible to prevent the scattering of dust generated during cutting.

[0057] Next, the cutting mechanism 21 will be described in detail with reference to Figures 5 to 7. Figure 5 is a right side view of the cutting mechanism 21, Figure 6 is a front view of the cutting mechanism 21, and Figure 7 is a bottom view of the cutting mechanism 21.

[0058] 5 and 6, the cutting mechanism 21 has a mounting mechanism 213 mounted on the arm tip 221, which is the tip of the arm 22. The mounting mechanism 213 has a pair of mounting plates 2131, 2131 provided symmetrically in the rotation direction around the lifting and lowering direction of the arm tip 221. The spacing between the mounting plates 2131, 2131 is set to a dimension that allows the tip of the arm 22 to be inserted between the mounting plates 2131, 2131. A link mechanism 222 is provided at the arm tip 221. The link mechanism 222 has the function of rotating the cutting blade mechanism 21A of the cutting mechanism 21 in the lifting and lowering direction relative to the arm tip 221.

[0059] The upper end of each mounting plate 2131, which faces the arm tip 221, is curved in a concave shape so as not to obstruct the vertical rotation of the cutting blade mechanism 21A relative to the arm tip. Through holes 2131a and 2131b are formed at both ends of the upper end of each mounting plate 2131. Pin members 2141 and 2142 are inserted through the through holes 2131a and 2131b, respectively. One pin member 2141 is rotatably inserted through a through hole 222a formed in the driven end of the link mechanism 222. The other pin member 2142 is rotatably inserted through a through hole 221a formed in the arm tip 221. As a result, the cutting blade mechanism 21A is rotated and raised and lowered relative to the arm tip 221 around the pin member 2142 of the arm tip 221 as the driven end of the link mechanism 222 is moved.

[0060] 7, a drive mechanism 212 that hydraulically drives the cutting blade 211 to rotate is provided below the mounting mechanism 213. The drive mechanism 212 is composed of a hydraulic motor that generates rotational motion using hydraulic oil pressurized by a hydraulic pump. The drive mechanism 212 sends pressurized hydraulic oil into a chamber, and the pressure of the oil rotates the rotating shaft 2121. The rotation speed and torque can be freely adjusted by controlling the flow rate and pressure of the hydraulic oil.

[0061] It is preferable that the drive mechanism 212 controls the flow rate and pressure of hydraulic oil so that cutting can be performed at a constant rotational speed. This enables stable cutting even when the type and size of the cutting object are different. Specifically, to detect the rotational speed of the rotating shaft 2121 and stabilize it, a speed sensor such as an encoder or tachogenerator is attached to the rotating shaft 2121, and the measured rotational speed data is fed back to the control system. In the control system, the flow rate and pressure of hydraulic oil delivered from the hydraulic pump are input to a PID controller based on the speed data from the speed sensor. The PID controller then adjusts the input to the hydraulic motor based on the difference (deviation) between the target rotational speed and the actual rotational speed, thereby controlling the rotational speed of the rotating shaft 2121 using the flow rate and pressure of hydraulic oil.

[0062] Examples of drive mechanism 212 include a gear motor that uses internal or external gears to generate rotational motion, a vane motor in which multiple vanes (vanes) housed in slots inside a cylinder move radially using hydraulic pressure to generate rotation, and a piston motor that uses hydraulic pressure to move multiple pistons arranged around an axis to generate rotational motion.

[0063] The cutting blade mechanism 21A, to which the rotational driving force of the drive mechanism 212 is transmitted, is provided at both ends of the arm tip 221 of the drive mechanism 212 in the pivoting direction (horizontal direction). The cutting blade mechanism 21A includes a cutting blade 211, the rotation axis 2121 of the drive mechanism 212 being connected to the rotation center, and a cover member 215 located above the rotation center of the cutting blade 211 and covering the periphery of the cutting blade 211. The cover member 215 prevents dust from scattering when the cutting blade 211 cuts the waste plastic material and also prevents fragments from scattering if the cutting blade 211 is broken. The spacing between the cutting blades 211 is set to the cutting spacing of the waste plastic material. As a result, when cutting the waste plastic material, the waste plastic material can be cut at intervals of, for example, 80 cm by repeatedly rotating the arm tip 221 and performing the cutting operation of the cutting blade mechanisms 21A.

[0064] The amount of rotational movement of the arm tip 221 may be determined visually by an operator by shining a laser pointer provided on the arm tip 221 onto the waste plastic material to mark two points at a predetermined interval, such as 80 cm, or it may be determined automatically based on the distance to the arm tip 221 and the rotation angle of the arm 22.

[0065] Each cutting blade mechanism 21A is provided with a water spray mechanism 25. The water spray mechanism 25 has a nozzle member 251 and a hose connecting member 252 provided at the base end of the nozzle member 251. The hose connecting member 252 is connected to the water supply mechanism 26 via the water supply piping 261 shown in FIG. 4, so that water is supplied from the water supply mechanism 26. The nozzle member 251 is horizontally disposed above the range from the rotation center of the cutting blade 211 to the cover member 215. The base (one end) of the nozzle member 251 is connected to the cover member 215. The free end (other end) of the nozzle member 251 is located on the other end side of the rotation center of the rotation shaft 2121. A plurality of water spray nozzles 251a are formed on the side surface of the nozzle member 251. These water jet nozzles 251a are arranged at equal intervals in the longitudinal direction of the nozzle member 251, and spray water to prevent the scattering of dust that is generated when cutting waste plastic material.

[0066] These water jets 251 a may be configured to spray water along the side of the cutting blade 211, or may be configured to spray water toward the peripheral edge of the cutting blade 211. Furthermore, the water jets 251 a may be provided with a nozzle member. Examples of the nozzle member include a flat spray nozzle that creates a uniform water curtain along the side of the cutting blade, which is effective for cooling during cutting and removing cutting dust; a jet nozzle that enhances the cooling effect and helps wash away cutting dust by concentrating a high-pressure water flow on a specific part of the cutting blade 211; a fog nozzle that sprays fine mist of water to cool the cutting blade 211 over a wide area and suppress the scattering of dust; and a shower nozzle that is a nozzle with multiple small water jets integrated together, which can uniformly cool a wide area of ​​the cutting blade 211.

[0067] 8 , the cutting device 2 may have a water spray mechanism 25A provided at the middle of the arm 22. Specifically, the cutting device 2 may include a hydraulic excavator 20 including an excavator body 23 moved by traveling crawlers 24 and an arm 22 provided on the excavator body 23, a cutting mechanism 21 detachably provided at the tip of the arm 22 for cutting the waste plastic material to a predetermined size, a water spray mechanism 25A provided at the middle of the arm 22 for spraying water onto the cutting mechanism, and a water supply mechanism 26 provided on the excavator body 23 for supplying water to the cutting mechanism 21 and the water spray mechanism 25A. With the above configuration, when cutting the waste plastic using water as a driving force for the cutting mechanism 21, scattering of dust generated during cutting can be prevented by spraying water over the entire cutting area. In addition, the cutting device 2 may be equipped with both a water spray mechanism 25A provided in the middle of the arm 22 and a water spray mechanism 25 provided on the cutting blade mechanism 21A.In this case, dust dispersion is prevented both overall and locally, thereby making it possible to further improve the working environment.

[0068] (First Crushing Step S21: Rough Crusher 12) The rough crusher 12 has a shredder structure. Specifically, the rough crusher 12 is configured such that a pair of rotating drums, each with a series of blades attached to its periphery, are arranged in parallel, overlapping with each other so that the sides of the blades of the rotating drums face each other, and the rotating drums are rotated by a drive mechanism so that the blades at the overlapping portion move from top to bottom. As a result, when cut pieces transported by the first conveyor 111 are fed into the rough crusher 12, the cut pieces are drawn into the overlapping portion by the rotation of the rotating drums, and are crushed into fine cut pieces by the cutting force of the blades. The crushed cut pieces then fall from the overlapping portion of the rotating drums.

[0069] (Powder polishing and sorting process S33: Powder polishing and sorting device 17) As shown in Figure 9, the powder polishing and sorting device 17 has the function of further finely grinding the crushed material crushed in the crushing process S31 by cutting and abrasion, and also has a grinding circulation function of finely grinding again the crushed material that was not finely ground.

[0070] Specifically, the powder polishing and sorting apparatus 17 includes a crushing mechanism 171 that crushes the crushed material (raw material) crushed by the crusher 15 in the crushing step S31 of Fig. 3 , and a feeder mechanism 172 that feeds the raw material to the crushing mechanism 171 at constant rates. The feeder mechanism 172 includes a raw material tank 1721 that stores the raw material before crushing in the crushing mechanism 171, an exhaust fan 1732 that exhausts air from the raw material tank 1721, and a feeder 1732 that feeds the crushed material (raw material) stored in the raw material tank 1721 at constant rates. The raw material tank 1721 has a cylindrical upper portion and an inverted conical lower portion, and the center of the upper surface is connected to the exhaust fan 1732 via an exhaust pipe 1737. This allows the exhaust fan 1732 to exhaust the air from the raw material tank 1721 and reduce the pressure inside the raw material tank 1721, thereby fluidizing the crushed material in a powder state and allowing it to flow into the raw material tank 1721. The feeder mechanism 172 has a cyclone collector function of a cyclone collector mechanism 175 described later.

[0071] A crushing mechanism 171 is disposed below the feeder mechanism 172. The discharge outlet of the feeder mechanism 172 and the inlet of the crushing mechanism 171 are connected via a feed pipe 1735, and the crushing mechanism 171 has the function of further crushing the crushed material (raw material) supplied from the feeder mechanism 172 into finely crushed material. Details of the crushing mechanism 171 will be described later. The discharge outlet of the crushing mechanism 171 is connected to a cyclone collector mechanism 175 via a feed pipe 1731. The cyclone collector mechanism 175 has a cyclone body 1751, an exhaust fan 1752 connected to the center of the upper surface of the cyclone body 1751 via an exhaust pipe 1733, and a feeder 1753 that feeds the crushed material stored in the cyclone body 1751 to the sorting device 174 at a constant rate.

[0072] As a result, in the cyclone collector mechanism 175, a mixed flow of air and pulverized material, including finely pulverized material discharged from the pulverizing mechanism 171, is blown into the cyclone body 1751 in the circumferential direction at high speed, causing the mixed flow to rotate within the cyclone body 1751. Then, the pulverized material powder, including the finely pulverized material, is pressed against the outer wall by centrifugal force and falls downward along the wall surface, while the air is discharged from the center of the upper surface of the cyclone body 1751 without being subjected to centrifugal force. The powder that has fallen below the cyclone body 1751 is fed to the sorting device 174, which is arranged below the cyclone body 1751, from a discharge port formed at the bottom end of the cyclone body 1751.

[0073] The sorting device 174 has the function of sorting pulverized material into finely pulverized material and non-finely pulverized material. Specifically, the sorting device 174 has a sorting device main body 1741 equipped with a sieve and a vibration mechanism (not shown) that vibrates the sorting device main body 1741. The sorting device main body 1741 has a first outlet 1741a for discharging the sorted finely pulverized material and a second outlet 1741b for discharging powder other than the finely pulverized material. As a result, when the sorting device main body 1741 is vibrated by the vibration mechanism, finely pulverized material smaller than the mesh size of the sieve passes through the sieve and falls downward, while the other pulverized material remains on the sieve. The finely pulverized material that falls through the sieve is discharged from the first outlet 1741a, while the pulverized material with a larger particle size other than the finely pulverized material that remains on the sieve is discharged from the second outlet 1741b. The second outlet 1741b is connected to the crushing mechanism 171 via a feed pipe 1736, and crushed materials other than the finely crushed material are returned to the crushing mechanism 171 to be crushed again.

[0074] Thus, the powder polishing and sorting apparatus 17 has a crushing mechanism 171 that further crushes the crushed material by cutting and abrasion, a sorting device 174 that sorts the crushed material, including the finely crushed material crushed by the crushing mechanism 171, into the finely crushed material and other crushed material, i.e., crushed material with a particle size larger than that of the finely crushed material, and a crushing circulation path (feed pipe 1736) that returns the crushed material other than the finely crushed material sorted by the sorting device 174 to the crushing mechanism 171 and crushes it again. As a result, even if the target degree of crushing cannot be achieved in one crushing, the powder polishing and sorting apparatus 17 extends the crushing time by circulating the crushed material other than the finely crushed material sorted by the sorting device 174 through the crushing circulation path, making it possible to more efficiently achieve the target degree of crushing and to uniform the particle size distribution of the finely crushed material.

[0075] 10 , the crushing mechanism 171 includes a housing 1711, a cylindrical rotor 1712 that is rotatably housed in the housing 1711 and has a rotation axis that coincides with the central axis, and a plurality of cutting and grinding blades 1713 that are provided at equal intervals on the outer circumferential surface of the rotor 1712. The cutting and grinding blade 1713 includes a blade member that cuts raw material such as the material to be crushed, and a grinding member that is formed on the side of the blade member and grinds the raw material. The crushing mechanism 171 further includes a rotation drive mechanism 1714 that is connected to the rotation shaft of the rotor 1712 and drives the rotor 1712 to rotate at high speed.

[0076] 3 , a feeder mechanism 172 that feeds a constant amount of raw material to the crushing mechanism 171, and a cyclone collector mechanism 175 that uses an airflow to collect the powder material (finely crushed material, crushed material) formed by crushing the raw material in the crushing mechanism 171. The crushing mechanism 171 includes a housing 1711, a cylindrical rotor 1712 that is rotatably housed in the housing 1711 and has a rotation axis that coincides with the central axis, a plurality of cutting and polishing blades 1713 that are provided at equal intervals on the outer periphery of the rotor 1712 and have a blade member that cuts the raw material and a polishing portion formed on the side of the blade member that polishes the raw material, and a rotation drive mechanism 1714 that is connected to the rotation axis of the rotor 1712 and rotates the rotor 1712 at high speed.

[0077] According to the above configuration, the pulverized raw material is pulverized by both cutting and polishing, so that powders of different particle sizes and hardness, such as FPR and adhesives, can be pulverized to a uniform particle size.

[0078] (Recycled fiber reinforced resin) The recycled fiber reinforced resin produced as described above is made of a pulverized waste plastic material containing a fiber reinforced resin and at least one impurity component selected from a wood component, a corrosion prevention paint component, a urethane component, and a rubber component, and has an average particle size of 10 μm or more and 50 μm or less.

[0079] The recycled fiber-reinforced resin with the above-mentioned structure has a fine average particle size of 10 μm to 50 μm, which improves moldability during processing. This improves the fluidity of waste plastic materials, particularly in processes such as injection molding and extrusion molding, making it possible to improve the dimensional accuracy and appearance quality of products.

[0080] For example, wood fiber, a wood component, acts as a natural reinforcing material, reducing thermal conductivity and improving thermal insulation. The addition of wood components also gives molded products a natural appearance and feel. Metal components, however, can weaken synthetic resins and cause other physical deterioration, so they are separated using an electrostatic separator.

[0081] When the material contains anti-corrosion paint components, it has improved corrosion resistance, making it suitable for applications exposed to harsh environments or chemicals. When the material contains urethane components, the urethane components have excellent shock absorption and durability, making it suitable for applications requiring impact-resistant products or a comfortable grip. When the material contains rubber components, the rubber has excellent flexibility and elasticity, making it suitable for applications requiring vibration absorption and soundproofing.

[0082] (Recycled Resin Composition) The recycled resin composition produced as described above contains at least 20% by mass to 30% by mass of recycled fiber-reinforced resin and 65% by mass to 78% by mass of plastic resin. Examples of the "plastic resin" include cross-linked polyethylene (XLPE), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), and polyphenylene sulfide (PPS). The power distribution lines can be made from wires removed when updating wind turbine generators.

[0083] The recycled resin composition having the above-described configuration has the property that the plastic resin increases its fluidity when heated, making it easy to mold, thereby improving the efficiency of the molding process and increasing the freedom of product shape and design. Furthermore, the recycled resin composition can improve its strength and toughness by appropriately adjusting the blending ratio of the recycled fiber-reinforced resin and the plastic resin. Furthermore, durability can be improved by appropriately selecting the type of plastic resin.

[0084] (Recycled Resin Molded Article) A recycled resin molded article containing a recycled resin composition can be used in a variety of applications because the recycled resin composition is lightweight, strong, and has a low environmental impact. Specifically, it can be used in building materials such as bricks, building boards, plywood, roofing materials, window frames, doors, flooring materials, and wall materials, machine parts such as automobile parts, home appliance parts, and industrial machinery parts, electric and electronic parts such as electric wires and cables and housings for electronic components, and daily necessities such as containers, bags, shoes, furniture, toys, and sporting goods. More specifically, it can be used as a base mat for a solar power generation device.

[0085] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Furthermore, the effects described in the above-described embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the above-described embodiments. Furthermore, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the configurations described.

[0086] 1 Manufacturing system 2 Cutting device 12 Coarse crusher 13 Fine crusher 14 Cash silo 15 Crusher 16 Gravity separator 17 Powder polishing separator 18 Electrostatic separator

Claims

1. A method for producing a recycled fiber-reinforced resin, comprising: a cutting step of cutting a waste plastic material containing a fiber-reinforced resin and derived from at least one selected from a windmill blade, a bathtub, and a hull into a substantially plate-shaped member in a range of 50 cm square to 1 m square at a waste plastic material dismantling site; and a crushing step of transporting the substantially plate-shaped member to a resin manufacturing factory and crushing the substantially plate-shaped member at the manufacturing factory, wherein the crushing step is a step of crushing the substantially plate-shaped member in multiple stages to make the final average particle size of the crushed material 10 μm or more and 50 μm or less.

2. The method for producing a recycled fiber-reinforced resin according to claim 1, wherein the crushing step includes: a first crushing step of crushing the substantially plate-shaped member so that the average particle size becomes 20 mm or more and 60 mm or less; a second crushing step of crushing the crushed material after the first crushing step so that the average particle size becomes 10 mm or more and 50 mm or less; and a crushing step of crushing the crushed material after the second crushing step so that the average particle size becomes 10 μm or more and 50 μm or less.

3. A method for producing a recycled resin composition, comprising a kneading and molding step having a kneading object containing at least 20% by mass or more and 30% by mass or less of the recycled fiber-reinforced resin obtained by the production method according to claim 1 and 65% by mass or more and 78% by mass or less of a plastic resin, and having an extruder or a compressor after kneading.

4. The method for producing a recycled resin composition according to claim 3, wherein the kneading object contains a virgin thermoplastic resin produced from a raw material.

5. The method for producing a recycled resin composition according to claim 3, wherein the plastic resin includes a resin used in at least one selected from a wind power plant, a bathroom, and a ship interior.

6. A method for producing a resin molded body, comprising a molding step of molding the recycled resin composition obtained by the production method according to claim 3.

7. A hydraulic excavator comprising a shovel body moved by a crawler for traveling and an arm provided on the shovel body, a cutting mechanism detachably provided at the tip of the arm for cutting waste plastic materials into predetermined dimensions, a water spraying mechanism for spraying water onto the cutting mechanism, and a water supply mechanism provided on the shovel body for supplying water to the cutting mechanism and the water spraying mechanism. The cutting mechanism includes a plurality of cutting blades provided at a separation width of the predetermined dimensions for cutting the waste plastic materials, and a drive mechanism for rotationally driving the cutting blades by hydraulic pressure. A cutting device.

8. A pulverizing and polishing device having a pulverizing mechanism for pulverizing a raw material, a feeder mechanism for feeding the raw material to the pulverizing mechanism by a fixed amount, and a cyclone collector mechanism for collecting powder materials formed by pulverizing the raw material in the pulverizing mechanism by an air flow. The pulverizing mechanism includes a container, a cylindrical rotating body rotatably accommodated in the container with the rotation axis aligned with the central axis, a plurality of cutting and polishing blades provided at equal intervals on the outer peripheral surface of the rotating body for cutting the raw material, and a polishing portion formed on the side surface of the blade member for polishing the raw material, and a rotation drive mechanism connected to the rotation axis of the rotating body for rotationally driving the rotating body at a high speed.

9. A recycled fiber-reinforced resin comprising a pulverized waste plastic material containing a fiber-reinforced resin and at least one or more impurity components selected from a wood component, a corrosion prevention paint component, a urethane component, and a rubber component, and having an average particle diameter of 10 μm or more and 50 μm or less.

10. A recycled resin composition containing at least 20% by mass or more and 30% by mass or less of the recycled fiber-reinforced resin according to claim 9 and 65% by mass or more and 78% by mass or less of a plastic resin.

11. A recycled resin molded body containing the recycled resin composition according to claim 10.

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