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

Abstract

To solve the problems in the recycling of a dismantled windmill blade and provide a recycling system of a dismantled windmill blade.SOLUTION: 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 the 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 pulverized matter having a final average particle diameter from 10 μm to 50 μm inclusive.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Fiber Reinforced Plastics (FRP) are composite materials in which reinforcing fibers such as glass fibers and carbon fibers are dispersed in an unsaturated polyester resin or an epoxy resin, significantly improving the specific strength and specific modulus. Among FRPs, in particular, Glass Fiber Reinforced Plastic (GFRP) has high mechanical properties and chemical stability, is inexpensive, is lightweight compared to metal materials, and can be mass-produced. Therefore, GFRP is widely used in bathtubs, ship hull materials, etc.

[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 a type of thermosetting resin and irreversibly form a three-dimensional structure accompanied by a cross-linking reaction during molding. Once the three-dimensional structure is formed, it can no longer be returned to the original liquid raw material by normal heating or solvent treatment. Therefore, it is difficult to recycle GFRP that has reached the end of its life, and in fact, it is incinerated and landfilled as industrial waste.

[0004] However, research on the recycling of GFRP has been progressing from the perspective of environmental protection trends in recent years, including SDGs (Sustainable Development Goals). The recycling of GFRP is being studied from the viewpoints of material recycling and chemical recycling.

[0005] Material recycling is a form of recycling in which discarded materials are physically and mechanically processed and used as additives for other materials. A method of practically applying this is to finely pulverize waste GFRP materials and reuse them as fillers for cement. In addition, it has also been proposed to use finely pulverized thermosetting waste plastics (waste FRP) as fillers for thermoplastic waste plastics (polypropylene, PP), create pellets for injection molding, and use them as plastic materials for injection molding (Non-Patent Document 1).

[0006] Chemical recycling is a method in which waste GFRP materials are chemically treated to decompose unsaturated polyester resins into raw material substances, reduce their molecular weight, and liquefy them, thereby separating and recovering glass fibers, which are reinforcing materials, and reusing the resin raw materials and the separated glass fibers as raw materials for GFRP again. However, the high processing cost is an issue. Although research-level investigations are progressing, at present, it has not become as widespread as material recycling.

Prior Art Documents

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] By the way, in addition to bathtubs and ship hull materials, windmill blades used in wind power plants are also made of FRP. However, the diameter of windmill blades is about 80 m, and the weight per blade reaches about 5 tons. In addition, wind power generation is generally carried out in remote areas. Therefore, optimization is required in terms of both the disassembly cost and the transportation cost from the disassembly location to the material recycling factory. In this regard, recycling windmill blades is even more difficult than recycling bathtubs and ship hull materials. To realize a recycling system for disassembled windmill blades, existing recycling technologies alone are not sufficient, and problems must be solved from the perspective of disassembly efficiency.

[0009] In addition, disassembled windmill blades contain not only FRP but also wood chips. Therefore, when recycling them as a filler for cement, the wood chips contained in the disassembled windmill blades can be an obstacle. In terms of efficiency, it is better if the wood chips do not need to be removed, and the development of applications that do not require the removal of wood chips is required.

[0010] Looking at Japan, wind power plants have been continuously built since 1995, and a total of 2,626 units are in operation (as of December 2022). On the other hand, the disassembly and removal of wind turbines that have reached the end of their approximately 20-year lifespan increased to 72 units in 2023 and will increase to 100 - 200 units per year thereafter. Since three windmill blades have been used per unit until now, the weight of windmill blades per unit is about 15 tons, and it is expected that there will be 1,500 tons of waste per year only in Japan.

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

[0012] Therefore, the provision of a recycling system for disassembled windmill blades is an urgent issue.

[0013] The present invention has been made in view of such circumstances, and an object thereof is to solve problems in recycling disassembled wind turbine blades and to realize a recycling system for disassembled wind turbine blades.

Means for Solving the Problems

[0014] The inventors of the present invention cut the disassembled wind turbine blade into a predetermined size at the wind turbine disassembly site, then transported the cut material to the production site of the recycled resin, and pulverized the cut material at the production site, and found that a recycled fiber-reinforced resin having an average particle diameter of 10 μm or more and 50 μm or less can be obtained, thus solving at once the problems of the weight of the wind turbine blade and the transportation from the wind power generation site to the factory, and leading to the completion of the present invention. Specifically, the present invention provides the following.

[0015] The present invention is a method for producing a recycled fiber-reinforced resin, comprising: a cutting step of cutting a waste plastic material derived from at least one selected from a wind turbine blade, a bathtub, and a ship hull and containing a fiber-reinforced resin into a substantially plate-shaped member in a range of 50 cm square to 1 m square at the disassembly site of the waste plastic material; 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 so that the final average particle diameter of the crushed material is 10 μm or more and 50 μm or less.

[0016] According to the present invention, since the waste plastic material is cut into a substantially plate-shaped member of 1 m square or less at the disassembly site, it can be loaded onto and unloaded from a vehicle in terms of both size and weight, and the transportation cost from the disassembly site to the material recycling factory can be suppressed. Further, since the size of the substantially plate-shaped member is 50 cm square or more, the crushed blade at the disassembly site can be quickly discharged, and the construction period will not be unnecessarily prolonged, so that the disassembly cost can be suppressed. Therefore, optimization can be achieved in terms of both the disassembly cost and the transportation cost from the disassembly site to the material recycling factory.

[0017] Therefore, according to the present invention, since the problems of the weight of the wind turbine blade and the transportation from the wind power generation site to the factory can be solved at once, a recycling system for disassembled wind turbine blades can be realized.

[0018] Further, in the present invention, the crushing step preferably 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.

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

[0020] Further, the present invention is a method for producing a recycled resin composition, which has a kneading and molding step having an extruder or a compressor after kneading a kneading object containing at least 20% by mass or more and 30% by mass or less of the recycled fiber-reinforced resin and 65% by mass or more and 78% by mass or less of the plastic resin. Further, the present invention is a method for producing a recycled resin composition, which has a kneading step of kneading a kneading object containing at least 20% by mass or more and 30% by mass or less of the recycled fiber-reinforced resin and 65% by mass or more and 78% by mass or less of the plastic resin using an extruder. In this method, the plastic resin preferably contains at least one resin selected from a wind power plant, a bathroom, and a ship interior.

[0021] Recycled fiber-reinforced resins have the drawback of being too hard to recycle. However, according to the present invention, by mixing the recycled fiber-reinforced resin with a plastic resin, it becomes possible to uniformly knead using an extruder, and the problem that FRP is too hard to recycle can be solved.

[0022] Further, the present invention is a method for producing a recycled resin composition, in which the kneading object contains a virgin thermoplastic resin produced from a raw material.

[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 them uniformly using an extruder, and solving the problem that FRP is too hard to recycle. Also, since the object of the present invention is to make a thermoplastic resin molded product into an inexpensive recycled fiber reinforced resin by effectively utilizing used FRP, the kneading object can be either virgin or recycled thermoplastic resin.

[0024] The fiber reinforced resin derived from at least one selected from windmill blades, bathtubs, and ship hulls contains at least one impurity component selected from wood components, corrosion prevention paint components, urethane components, and rubber components. According to the present invention, since the recycled fiber reinforced resin functions as a filler for the plastic resin, unlike the case of recycling the recycled fiber reinforced resin as a filler for cement, even if a small amount of impurity components are contained, it does not affect the recycled resin composition.

[0025] In addition, since the recycled fiber reinforced resin has high strength, it can enhance the strength of the recycled resin composition and add value to mixing the recycled fiber reinforced resin. Also, when the waste plastic material is derived from a windmill, the recycled fiber reinforced resin contains a wood component, and having a wood component in the filler can suppress the amount of plastic resin used. Therefore, advantages can also be given to the wood component that was originally an impurity. Similarly, even when the recycled fiber reinforced resin contains a urethane component or a rubber component, advantages of suppressing the amount of plastic resin used can be given.

[0026] Therefore, according to the present invention, a recycling system for disassembled windmill blades can be realized.

Advantages of the Invention

[0027] According to the present invention, the problems in recycling disassembled windmill blades can be solved, and a recycling system for disassembled windmill blades can be realized.

Brief Description of the Drawings

[0028]

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Embodiments for Carrying Out the Invention

[0029] Hereinafter, an example of a preferred embodiment for carrying out the present invention will be described. Note that this is merely an example, and the technical scope of the present invention is not limited thereto.

[0030] (Method for Manufacturing Regenerated Fiber-Reinforced Resin) As shown in Figure 1, the method for manufacturing the regenerated fiber-reinforced resin of the present embodiment includes a cutting step S1 of cutting a waste plastic material containing a fiber-reinforced resin and difficult to transport while maintaining its original shape into a substantially plate-shaped member in the range of 50 cm square to 1 m square at the disassembly site of the waste plastic material, and a crushing step S2 of transporting the substantially plate-shaped member to a resin manufacturing factory and crushing the substantially plate-shaped member at the manufacturing factory so that the average particle diameter is 10 μm or more and 50 μm or less.

[0031] Here, the "fiber-reinforced resin" is a composite material of fiber and resin. Examples of the fiber include glass fiber, carbon fiber, aramid fiber, Kevlar (registered trademark) fiber, etc. Examples of the resin include epoxy resin, polyester resin, phenolic resin, etc. Thus, the method for manufacturing the recycled fiber-reinforced resin of the present embodiment is one of the recycling methods for all waste using both fiber-reinforced resins, i.e., glass fiber-reinforced resin (Glass-Fiber Reinforced Plastic) which is G-FRP and carbon fiber-reinforced resin (Carbon-Fiber Reinforced Plastic) which is C-FRP, and their raw materials. "Difficult to transport while maintaining the original shape" means that special transportation means are required due to factors such as weight and size in order to transport the waste plastic material while maintaining its original shape. The special transportation means are large transportation equipment such as large trucks and ships. The "waste plastic material" preferably contains a fiber-reinforced resin derived from at least one selected from windmill blades, bathtubs, and ship hulls, but is not particularly limited as long as it is a member formed of a fiber-reinforced resin. For example, in addition to windmill blades, bathtubs, and ship hulls, it may also be automotive parts, aircraft parts, building materials, civil engineering materials, sports goods, etc.

[0032] In the cutting step S1, the reason for cutting the waste plastic material into a substantially plate-shaped member with a size of 1 m square or less at the dismantling site is that it can be loaded onto and unloaded from a vehicle in terms of both size and weight, and the transportation cost from the dismantling site to the material recycling factory can be suppressed, and also because it can be directly fed into the factory crushing machine. Also, the reason for the size of the substantially plate-shaped member being 50 cm square or more is that the crushed blades at the dismantling site can be quickly discharged, and the dismantling cost can be suppressed because the construction period will not be unnecessarily prolonged. Therefore, when cutting the waste plastic material into a substantially plate-shaped member in the range of 50 cm square to 1 m square at the dismantling site, optimization is possible in terms of both the dismantling cost and the transportation cost from the dismantling site to the material recycling factory.

[0033] As a result, for example, problems such as the weight of the wind turbine blade and the transportation from the wind power generation site to the factory can be solved all at once, so that a recycling system for disassembled wind turbine blades can be easily realized. That is, a recycling system for waste plastic materials that require special transportation means due to factors such as weight and size is easily realized by ordinary transportation means. Note that ordinary transportation means refer to transportation using small transport equipment such as small / medium-sized trucks and vans.

[0034] In the crushing step S2, the waste plastic material of the substantially plate-shaped member in the range of 50 cm square to 1 m square may be crushed all at once until the average particle size becomes 10 μm or more and 50 μm or less, or may be gradually crushed in multiple stages. The reason for this is that when the waste plastic material, which is a cut product having a stable three-dimensional structure, is crushed in multiple stages, the load on the crushing device at each stage is reduced, so that damage to the crushing device can be suppressed.

[0035] For example, the crushing step S2 includes a first crushing step S21 for crushing the substantially plate-shaped member so that the average particle size becomes 20 mm or more and 60 mm or less, and a second crushing step S22 for crushing the crushed product after the first crushing step S21 so that the average particle size becomes 10 mm or more and 50 mm or less.

[0036] As also shown in FIG. 2, the first crushing step S21 is a step of roughly crushing the waste plastic material, which decomposes the waste plastic material from large chunks into small pieces and efficiently performs the subsequent second crushing step S22. Examples of the coarse 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. The cutter mill is configured to cut the waste plastic material by a rotating cutter. The roller mill is configured to compress and crush the waste plastic material by a rotating roller. The hammer mill is configured to crush the waste plastic material by a rotating hammer. The jaw crusher has two plates, a "fixed jaw" with one side fixed and a "moving jaw" vibrating on the opposite side, and uses an eccentric shaft or a link mechanism to swing the moving jaw up and down to compress and crush the waste plastic material between it and the fixed jaw. The shredder is a crushing device composed of a rotating drum or disk with a series of blades or hammers attached, and shreds the waste plastic material by the blades or hammers rotating at high speed.

[0037] The second crushing process S22 is a process of finely crushing the waste plastic material, making the particles of the waste plastic material smaller than the crushed product of the first crushing process S21, and further finely dispersing the fibers, resins, and metals inside the waste plastic material by fine crushing. Examples of the fine crusher 13 used in the second crushing process S22 include a cutter mill, a ball mill, a converging mill, a rod mill, and a disk mill. The cutter mill has the same configuration as the coarse crushing. The ball mill is configured to fill a rotating cylinder with media such as balls and beads and crush the waste plastic material with the media. The converging mill is configured to arrange a screw in a rotating cylinder and crush the waste plastic material with the screw. The rod mill is configured such that steel rods (rods) are horizontally arranged in a cylindrical drum, the rods rise due to the rotation of the drum, and the waste plastic material is crushed by the impact and friction when falling due to gravity. The disk mill is configured such that two disks are arranged facing each other, one of the disks is fixed while the other disk is rotated, and the waste plastic material introduced between the disks is crushed.

[0038] The method for manufacturing the regenerated fiber-reinforced resin has a powder process S3 provided in the latter stage of the crushing process S2. The powder process S3 is a process of pulverizing the crushed product crushed in the crushing process S2 and selecting desirable components, such as separating plastic and metal. Specifically described, the powder process S3 has a pulverizing process S31, a specific gravity separation process S32, a powder polishing and separation process S33, and an electrostatic separation process S34.

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

[0040] The specific gravity separation step S32 is a step of separating using the difference in specific gravity of the waste plastic material. For example, since the specific gravity varies depending on the type of plastic material and the type of metal, by using the specific gravity separator 16 in the specific gravity separation step S32, it is possible to separate the plastic materials by type or to separate the plastic material and the metal.

[0041] The powder polishing and separation step S33 is a step in which the pulverized material finely pulverized in the pulverization step S31 is further finely pulverized by cutting and abrasion in the powder polishing and separation device 17, and is a step of separating the finely pulverized material from other pulverized materials. This step can improve the accuracy of pulverization and the accuracy of separation between fibers and resin. As a result, when a thermoplastic resin such as a plastic resin or virgin thermoplastic resin is mixed with the finely pulverized fiber-reinforced resin and heat-molded, the miscibility with the thermoplastic resin is improved, so that the physical properties of the molded product, particularly strength and durability, can be improved. Furthermore, uniform particle size and uniform mixing improve the filling property, uniform heat conductivity, and fluidity during heat molding, and reduce shrinkage and distortion, so that the appearance and dimensional accuracy of the molded product can be improved.

[0042] The electrostatic separation step S34 is a step of separating using the differences in the types of waste plastic materials and the electrical properties of metals. For example, since the electrical properties vary depending on the types of plastic materials and metals, the electrostatic separation step S34 enables the separation of plastic materials by type and the separation of plastic materials from metals.

[0043] Note that, as shown in FIG. 3, the crushing step S31 may be paralleled to improve the processing capacity. In this case, when the processing required for fine crushing in the second crushing step S22 is completed in a shorter time than the processing required for fine pulverization in the crushing step S31, the finely crushed crushed material can be continuously flowed into a plurality of paralleled crushing steps S31 with increased processing capacity without temporarily storing it elsewhere as a work-in-progress. Also, the second crushing step S22 and the crushing step S31 may be paralleled. In this case, when the processing required for coarse crushing in the first crushing step S21 is completed in a shorter time than the processing required for fine crushing and fine pulverization in the second crushing step S22 and the crushing step S31, the coarsely crushed crushed material can be continuously flowed into a plurality of paralleled second crushing steps S22 and crushing steps S31 without temporarily storing it elsewhere as a work-in-progress.

[0044] (Method for manufacturing a recycled resin composition) As shown in FIG. 1, a kneading step S4, which is a step of manufacturing a recycled resin composition, is provided after the manufacturing steps (S1·S2·S3) of the recycled fiber-reinforced resin. The kneading step S4 is a step of kneading a kneading object containing at least 20% by mass or more and 30% by mass or less of the recycled fiber-reinforced resin obtained in the cutting step S1 and the crushing step S2 and 65% by mass or more and 78% by mass or less of a plastic resin using an extruder. According to the kneading step S4, although the recycled fiber-reinforced resin has a drawback of being too hard to recycle, by making it a recycled resin composition in which the recycled fiber-reinforced resin is mixed with a plastic resin, it becomes possible to knead it uniformly using an extruder, and the problem that FRP is too hard to recycle can be solved.

[0045] "Plasticizable resin" refers to a thermoplastic resin recovered from used plastics, which has the property of softening upon heating and solidifying upon cooling. Specifically, examples of general-purpose plastics include polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), and polycarbonate (PC). Also, examples of engineering plastics include polyamide (PA), polyester (PET), polycarbonate (PC), polyphenylene ether (PPE), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE).

[0046] The plasticizable resin can be applied to, for example, used plastics contained in container packaging, building materials, fibers, toys, and automotive parts. In addition, the plasticizable resin preferably includes a resin that coats waste electric wires that have been used in at least one selected from wind power plants, bathrooms, and inside ships. In this case, since the recycled resin composition obtained by mixing the recycled fiber-reinforced resin and the plasticizable resin is derived from at least one selected from windmill blades, bathtubs, and ship hulls, it contains at least one impurity component selected from wood components, corrosion prevention paint components, urethane components, and rubber components. As a result, since the recycled resin composition functions as a filler for the plasticizable resin, unlike the case of reusing the recycled fiber-reinforced resin as a filler for cement, even if a small amount of impurity components are contained, it will not affect the recycled resin composition.

[0047] In addition, since the recycled resin composition has high strength, it can enhance the strength of the recycled resin molded body, and added value can be given to mixing the recycled resin composition. Further, when the waste plastic material is derived from a windmill, the recycled fiber-reinforced resin contains a wood component, and the inclusion of the wood component in the filler can suppress the amount of the plastic resin used, which is advantageous. Therefore, advantages can also be given to the wood component that was originally an impurity. Similarly, even when the recycled fiber-reinforced resin contains a urethane component or a rubber component, it can have the advantage of suppressing the amount of the plastic resin used.

[0048] Furthermore, the kneading object in the kneading step S4 may include a recycled fiber-reinforced resin, a plastic resin, and a virgin thermoplastic resin. Here, "virgin thermoplastic resin" means a thermoplastic resin made from new raw materials that has not been recycled. The virgin thermoplastic resin has a higher purity compared to the plastic resin and does not contain other materials or impurities, so its quality is consistent. Also, the virgin thermoplastic resin has clear physical and chemical properties, is easy to predict performance, has stable behavior during the manufacturing process, and is easy to process. Thus, when the virgin thermoplastic resin is mixed with the recycled fiber-reinforced resin and the plastic resin, the thermoplasticity can be further enhanced, making it easier to knead them uniformly using an extruder and solving the problem that FRP is too hard to recycle.

[0049] The virgin thermoplastic resin is a resin that, like the plastic resin, has the property of softening upon heating and solidifying upon cooling. Specifically, as general-purpose plastics, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyamide (PA), and polycarbonate (PC) are exemplified. Also, as engineering plastics, polyamide (PA), polyester (PET), polycarbonate (PC), polyphenylene ether (PPE), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE) are exemplified.

[0050] (Method for manufacturing recycled resin molded article) After the kneading step S4 for manufacturing 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, then put into a molding machine, and molded into a desired shape by methods such as press molding, injection molding, and extrusion molding. Then, by cooling the molded product, the plastic resin is cured to retain the shape. After this, if necessary, post-treatments such as trimming, polishing, and painting are performed to obtain the final molded product.

[0051] (Manufacturing system 1 for recycled fiber-reinforced resin) As shown in FIGS. 2 and 3, the crushing step S2 and the sorting step S3 are provided in the manufacturing system 1 for the recycled fiber-reinforced resin and the resin composition. The manufacturing system 1 has a first conveyor 111 on which the cut pieces of the waste plastic material conveyed from the disassembling site of the waste plastic material in the cutting step S1 are placed, and a coarse crusher 12 of a first crushing step S21 connected to the carry-out end of the first conveyor 111. The coarse crusher 12 has a shredder mechanism and is configured to crush the cut pieces of the waste plastic material from large pieces about 50 cm to 100 cm square into small pieces about 20 mm to 40 mm square.

[0052] Below the coarse crusher 12, the carry-in end of a second conveyor 112 is arranged to receive the crushed cut pieces. The carry-out end of the second conveyor 112 is connected to a fine crusher 13 of a second crushing step S22. The fine crusher 13 has a cutter mill mechanism and is configured to make the waste plastic material into crushed material about 10 mm to 30 mm square, which is smaller than the crushed material of the first crushing step S21. Below the fine crusher 13, the carry-in end of a third conveyor 113 is arranged to receive the crushed cut pieces. The carry-out end of the third conveyor 113 is connected to a cache silo 14. The cache silo 14 is configured to temporarily store the crushed material conveyed from the fine crusher 13 and discharge the stored crushed material from two discharge ports formed at both ends in the width direction of the production line, respectively.

[0053] At each discharge port of the cache silo 14, the inlet portions of a pair of bucket conveyors 114, 114 are connected. The discharge ends of the bucket conveyors 114, 114 are connected to the crushers 15, 15 in the crushing process S31. The crushers 15, 15 are configured to crush crushed materials of about 10 mm to 30 mm square into crushed materials of about 30 μm to 50 μm. The crushers 15, 15 are connected to the specific gravity separators 16, 16 in the specific gravity separation process S32 via the first pneumatic conveyors 115, 115, and the resin and the metal are separated by the specific gravity separators 16, 16. The specific gravity separators 16, 16 are connected to the powder grinding and separation devices 17, 17 in the powder grinding and separation process S33. The powder grinding and separation devices 17, 17 are configured to crush and separate the crushed materials into crushed materials of about 20 μm to 30 μm. The powder grinding and separation devices 17, 17 are connected to the electrostatic separators 18, 18 in the electrostatic separation process S34 via the screw conveyors 117, 117. The electrostatic separators 18, 18 are configured to charge the crushed materials after separation, apply an electric field to the charged objects, and separate the crushed materials having different charges.

[0054] In addition, exhaust ducts 116, 116 are connected to the specific gravity separators 16, 16, the powder grinding and separation devices 17, 17, and the electrostatic separators 18, 18. The exhaust ducts 116, 116 are connected to a dust collector (not shown), and send out minute dust scattered during crushing or separation to the dust collector.

[0055] Next, the details of the main equipment used in the manufacturing system 1 will be described. (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 a traveling crawler 24 and an arm 22 provided on the shovel body 23, a cutting mechanism 21 detachably provided at the tip of the arm 22 for cutting waste plastic materials into predetermined dimensions, a water spraying mechanism 25 for spraying water onto the cutting mechanism 21, and a water supply mechanism 26 provided on the shovel body 23 for supplying water to the water spraying mechanism 25. The cutting mechanism 21 includes a plurality of cutting blades 211 provided at a separation width of a predetermined dimension for cutting waste plastic materials, and a drive mechanism 212 for rotationally driving the cutting blades 211 by hydraulic pressure.

[0056] According to the above configuration, by using hydraulic pressure as the driving force of the cutting mechanism 21, hard FRP can be stably cut, and by spraying water onto the cutting site, the scattering of dust generated during cutting can be prevented.

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

[0058] As also shown in Figs. 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 left - right direction in the turning direction around the lifting - lowering direction of the arm tip 221. The interval 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 a function of rotating the cutting blade mechanism 21A of the cutting mechanism 21 in the lifting - lowering direction with respect to the arm tip 221.

[0059] Each mounting plate 2131·2131 has an upper end portion facing the arm tip 221 curved in a concave shape so as not to obstruct the vertical rotation of the cutting blade mechanism 21A with respect to the arm tip. Through holes 2131a·2131b are formed at both ends of the upper end portion of each mounting plate 2131·2131. Pin members 2141·2142 are respectively inserted into the through holes 2131a·2131b. One pin member 2141 is rotatably inserted into a through hole 222a formed at the driven end of the link mechanism 222. The other pin member 2142 is rotatably inserted into a through hole 221a formed at the arm tip 221. Thus, the cutting blade mechanism 21A is rotated and lifted with respect to the arm tip 221 with the pin member 2142 of the arm tip 221 as the rotation center by the movement of the driven end of the link mechanism 222.

[0060] As also shown in FIG. 7, a drive mechanism 212 for rotationally driving the cutting blade 211 hydraulically is provided below the mounting mechanism 213. The drive mechanism 212 is constituted by a hydraulic motor that generates a rotational motion using hydraulic oil pressurized by a hydraulic pump. The drive mechanism 212 rotates the rotary shaft 2121 by sending the pressurized hydraulic oil into the chamber, and it is possible to freely adjust the rotational speed and torque by controlling the flow rate and pressure of the hydraulic oil.

[0061] Note that it is preferable that the flow rate and pressure of the hydraulic oil are controlled so that the drive mechanism 212 can cut at a constant rotational speed. In this case, stable cutting can be performed even when the type and size of the material to be cut are different. Specifically, a speed sensor such as an encoder or a tachogenerator is attached to the rotating shaft 2121 to detect the rotational speed of the rotating shaft 2121 and stabilize the rotational speed, and the measured rotational speed data is fed back to the control system. In the control system, the flow rate and pressure of the hydraulic oil sent from the hydraulic pump are input to the PID controller based on the speed data from the speed sensor. Then, the PID controller 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 the hydraulic oil.

[0062] Examples of the drive mechanism 212 include a gear motor that generates a rotational motion using internal or external gears, a vane motor in which a plurality of vanes (blades) housed in slots within a cylinder move radially by hydraulic pressure to generate rotation, and a piston motor that moves a plurality of pistons arranged around a shaft by hydraulic pressure to generate a 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 in the turning direction (horizontal direction) of the arm tip 221 in the drive mechanism 212. The cutting blade mechanism 21A has a cutting blade 211 whose rotating shaft 2121 of the drive mechanism 212 is connected to the rotation center portion, and a cover member 215 that is located above the rotation center portion of the cutting blade 211 and covers the peripheral edge portion of the cutting blade 211. The cover member 215 prevents dust from scattering when cutting waste plastic material with the cutting blade 211 and also prevents fragments from scattering when the cutting blade 211 is damaged. The interval between the cutting blades 211·211 is set to the cutting interval of the waste plastic material. Thereby, when cutting the waste plastic material, by repeating the turning movement of the arm tip 221 and the cutting operation of the cutting blade mechanisms 21A·21A, for example, the waste plastic material can be cut at 80 cm intervals.

[0064] Incidentally, the amount of rotational movement of the arm tip 221 may be determined visually by an operator by irradiating two marks at a predetermined interval such as 80 cm on the waste plastic material with a laser pointer provided at the arm tip 221, or may be automatically determined based on the distance of the arm tip 221 and the turning angle of the arm 22.

[0065] Each cutting blade mechanism 21A·21A is provided with a water spraying mechanism 25. The water spraying mechanism 25 has a nozzle member 251 and a hose connecting member 252 provided at the base end portion of the nozzle member 251. The hose connecting member 252 is connected to a water supply mechanism 26 via a water supply pipe 261 in FIG. 4, and water is supplied from the water supply mechanism 26. The nozzle member 251 is horizontally arranged at an upper position in the range from the rotation center portion of the cutting blade 211 to the cover member 215. The base portion (one end portion) of the nozzle member 251 is connected to the cover member 215. The free end portion (the other end portion) of the nozzle member 251 is located on the other end side of the rotation center portion of the rotating shaft 2121. A plurality of water spray ports 251a are formed on the side surface of the nozzle member 251. These water spray ports 251a are arranged at equal intervals in the longitudinal direction of the nozzle member 251, and by spraying water, the scattering of dust generated when cutting the waste plastic material is prevented.

[0066] Incidentally, these water spray ports 251a may be set to spray water along the side surface of the cutting blade 211, or may be set to spray water toward the peripheral edge portion of the cutting blade 211. Further, a nozzle member may be provided at the water spray port 251a. Examples of the nozzle member include a flat spray nozzle that forms a uniform water curtain along the side surface of the cutting blade and is effective for cooling during cutting work and removing cutting dust, a jet nozzle that concentrates a high-pressure water flow and sprays it onto a specific portion of the cutting blade 211 to enhance the cooling effect and assist in washing away the cutting powder, a fog nozzle that sprays fine mist-like water to cool the cutting blade 211 over a wide range and suppress the scattering of dust, and a shower nozzle in which a plurality of small water spray ports are integrated and can uniformly cool a wide range of the cutting blade 211.

[0067] As shown in FIG. 8, in the cutting device 2, the water jetting mechanism 25A may be provided at an intermediate portion of the arm 22. Specifically, the cutting device 2 includes a hydraulic excavator 20 including a shovel body 23 moved by a traveling crawler 24 and an arm 22 provided on the shovel body 23, a cutting mechanism 21 detachably provided at the tip of the arm 22 for cutting waste plastic materials into predetermined dimensions, a water jetting mechanism 25A provided at an intermediate portion of the arm 22 for jetting water to the cutting mechanism, and a water supply mechanism 26 provided on the shovel body 23 for supplying water to the cutting mechanism 21 and the water jetting mechanism 25A. According to the above configuration, while using water as the driving force of the cutting mechanism 21, when cutting waste plastic, by jetting water over the entire cutting site, it is possible to prevent the scattering of dust generated during cutting. Note that the cutting device 2 may include both the water jetting mechanism 25A provided at the intermediate portion of the arm 22 and the water jetting mechanism 25 provided on the cutting blade mechanism 21A. In this case, by preventing the scattering of overall dust and local dust, the working environment can be made even better.

[0068] (First Crushing Step S21: Primary Crusher 12) The primary crusher 12 has a shredder structure. Specifically, the primary crusher 12 is configured such that a pair of rotating drums with a series of blades attached around them are arranged in parallel, overlapped so that the side surfaces of the blades of the mutually 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 above downward. Thereby, when the cut pieces conveyed by the first conveyor 111 are input into the primary crusher 12, the cut pieces are drawn into the overlapping portion by the rotation of the rotating drums and crushed into fine cut pieces by the cutting force between the blades. Then, the crushed cut pieces fall from the overlapping portion of the rotating drums.

[0069] (Powder Polishing and Sorting Step S33: Powder Polishing and Sorting Device 17) As shown in FIG. 9, the powder grinding and sorting device 17 has a function of further finely grinding the ground material ground in the grinding process S31 by cutting and abrasion, and also has a grinding circulation function of re-grinding the ground material that has not been finely ground.

[0070] Specifically, the powder grinding and sorting device 17 includes a grinding mechanism 171 that grinds the ground material (raw material) ground by the grinder 15 in the grinding process S31 of FIG. 3, and a feeder mechanism 172 that feeds the raw material to the grinding mechanism 171 in a fixed amount. The feeder mechanism 172 includes a raw material tank 1721 that stores the raw material before grinding in the grinding mechanism 171, an exhaust fan 1732 that exhausts the air in the raw material tank 1721, and a feeding device 1722 that feeds the ground material (raw material) stored in the raw material tank 1721 in a fixed amount. The raw material tank 1721 is formed with a cylindrical upper part and an inverted conical lower part, and the central part of the upper surface is connected to the exhaust fan 1732 via an exhaust pipe 1737. Thereby, the air in the raw material tank 1721 is exhausted by the exhaust fan 1732, and the inside of the raw material tank 1721 is depressurized, so that the pulverized material in powder form can be made to flow and thereby be allowed to flow into the raw material tank 1721. Note that the feeder mechanism 172 has the cyclone collector function of the cyclone collector mechanism 175 described later.

[0071] Below the feeder mechanism 172, the grinding mechanism 171 is arranged. The discharge port of the feeder mechanism 172 and the inlet of the grinding mechanism 171 are connected via a feed pipe 1735. The grinding mechanism 171 has a function of further grinding the ground material (raw material) supplied from the feeder mechanism 172 into a finely ground material. The details of the grinding mechanism 171 will be described later. The discharge port of the grinding mechanism 171 is connected to the cyclone collector mechanism 175 via a feed pipe 1731. The cyclone collector mechanism 175 includes a cyclone body 1751, an exhaust fan 1752 connected to the central part of the upper surface of the cyclone body 1751 via an exhaust pipe 1733, and a feeding device 1753 that feeds the ground material stored in the cyclone body 1751 to the sorting device 174 in a fixed amount.

[0072] As a result, in the cyclone collector mechanism 175, a mixed flow of the pulverized material containing the finely pulverized material discharged from the pulverizing mechanism 171 and air is blown into the cyclone main body 1751 at high speed in the circumferential direction, and the mixed flow rotates within the cyclone main body 1751. Then, the pulverized material powder containing 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 central part of the upper surface of the cyclone main body 1751 without being affected by the centrifugal force. The powder that has fallen below the cyclone main body 1751 is fed from the discharge port formed at the lower end of the cyclone main body 1751 to the sorting device 174 disposed below the cyclone main body 1751.

[0073] The sorting device 174 has a function of sorting the pulverized material into the finely pulverized material and the material other than the finely pulverized material. Specifically, the sorting device 174 includes a sorting device main body 1741 provided with a sieve and a vibration mechanism (not shown) for vibrating the sorting device main body 1741. The sorting device main body 1741 has a first discharge port 1741a for discharging the sorted finely pulverized material and a second discharge port 1741b for discharging the powder other than the finely pulverized material. Thus, when the sorting device main body 1741 vibrates by the vibration mechanism, the finely pulverized material smaller than the mesh of the sieve passes through the sieve and falls downward, and the other pulverized material remains on the sieve. The finely pulverized material that has fallen from the sieve is discharged from the first discharge port 1741a, while the pulverized material with a larger particle size other than the finely pulverized material remaining on the sieve is discharged from the second discharge port 1741b. The second discharge port 1741b is connected to the pulverizing mechanism 171 via a feed pipe 1736, and the pulverized material other than the finely pulverized material is returned to the pulverizing mechanism 171 and pulverized again.

[0074] In this way, the powder grinding and sorting device 17 includes a grinding mechanism 171 that further finely grinds the crushed material by cutting and abrasion, a sorting device 174 that sorts the crushed material containing the finely ground material finely ground by the grinding mechanism 171 into the finely ground material and other crushed materials, that is, crushed materials with a particle size larger than that of the finely ground material, and a grinding circulation path (feed pipe 1736) that returns the crushed materials other than the finely ground material sorted by the sorting device 174 to the grinding mechanism 171 for re - grinding. Thereby, even when the target fineness cannot be achieved by a single grinding, the powder grinding and sorting device 17 extends the grinding time by circulating the crushed materials other than the finely ground material sorted by the sorting device 174 through the grinding circulation path, making it possible to obtain the target fineness more efficiently and also making it possible to equalize the particle size distribution of the finely ground material.

[0075] As also shown in FIG. 10, the grinding mechanism 171 includes a container 1711, a cylindrical rotor 1712 rotatably accommodated in the container 1711 with its rotation axis aligned with the central axis, and a plurality of cutting and grinding blades 1713 provided at equal intervals on the outer peripheral surface of the rotor 1712. The cutting and grinding blade 1713 has a blade member for cutting raw materials such as crushed materials and a grinding member formed on the side surface of the blade member for grinding the raw materials. Further, the grinding mechanism 171 has a rotation drive mechanism 1714 connected to the rotation axis of the rotor 1712 for driving the rotor 1712 to rotate at a high speed.

[0076] The powder grinding and sorting device 17 configured as described above includes a grinding mechanism 171 that grinds the raw material ground by the grinder 15 in the grinding process S31 of FIG. 3, a feeder mechanism 172 that feeds the raw material to the grinding mechanism 171 in a fixed quantity, and a cyclone collector mechanism 175 that recovers the powder material (finely ground material, ground material) formed by grinding the raw material in the grinding mechanism 171 by an air flow. The grinding mechanism 171 includes a container 1711, a cylindrical rotating body 1712 rotatably accommodated in the container 1711 with its rotation axis aligned with the central axis, a plurality of cutting and grinding blades 1713 provided at equal intervals on the outer peripheral surface of the rotating body 1712 and having a blade member for cutting the raw material and a grinding portion formed on the side surface of the blade member for grinding the raw material, and a rotation drive mechanism 1714 connected to the rotation axis of the rotating body 1712 for driving the rotating body 1712 to rotate at a high speed.

[0077] According to the above configuration, since the ground raw material is ground by both cutting and grinding, powders with different particle sizes and hardnesses such as FPR and adhesives can be ground to a uniform particle size.

[0078] (Recycled fiber reinforced resin) The recycled fiber reinforced resin manufactured as described above is composed of a ground material of a 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 has an average particle diameter of 10 μm or more and 50 μm or less.

[0079] The recycled fiber reinforced resin having the above configuration has a fine average particle diameter of 10 μm or more and 50 μm or less, so the moldability during processing is improved. Especially in processes such as injection molding and extrusion molding, the fluidity of the waste plastic material is improved, and it becomes possible to improve the dimensional accuracy and appearance quality of the product.

[0080] For example, wood fibers as a wood component function as a natural reinforcing material, can reduce the thermal conductivity, and make it possible to improve the heat insulation property. In addition, the addition of the wood component can give the molded product a natural appearance and feel. Note that since the metal component causes deterioration of physical properties such as making the synthetic resin brittle, it is separated by an electrostatic separator.

[0081] When containing a corrosion prevention paint component, the corrosion resistance can be improved, and it can be made into a recycled fiber reinforced resin suitable for applications particularly exposed to harsh environments or chemical substances. When containing a urethane component, since the urethane component has excellent shock absorption and durability, it can be made into a recycled fiber reinforced resin suitable for products resistant to shock or applications requiring a comfortable grip feeling. When containing a rubber component, since the rubber is excellent in flexibility and elasticity, it can be made into a recycled fiber reinforced resin effective as a vibration absorber or soundproof material.

[0082] (Recycled resin composition) The recycled resin composition manufactured as described above contains at least 20% by mass or more and 30% by mass or less of a recycled fiber reinforced resin and 65% by mass or more and 78% by mass or less of a plastic resin. Here, examples of the "plastic resin" include cross-linked polyethylene (XLPE), polyethylene (PE), polypropylene (PP), polybutylene terephthalate (PBT), and polyphenylene sulfide (PPS). In addition, for the distribution line, the electric wire removed when renewing the wind power generation device can be used.

[0083] The recycled resin composition having the above configuration has the property that the plastic resin increases its fluidity by heating and becomes easy to mold, so that the efficiency of the molding process can be improved and the degree of freedom in the shape and design of the product can be increased. Also, the recycled resin composition can improve strength and toughness by appropriately adjusting the blending ratio of the recycled fiber reinforced resin and the plastic resin. Furthermore, the durability can be improved by appropriately selecting the type of the plastic resin.

[0084] (Recycled resin molded body) Since the recycled resin molded article containing the recycled resin composition is lightweight, strong, and has a low environmental impact, it can be applied to various uses. Specifically, it can be applied to building materials such as bricks, building boards, plywood, roofing materials, window frames, doors, flooring materials, and wall materials, mechanical parts such as automotive parts, parts of household electrical appliances, and parts of industrial machines, electrical and electronic parts such as electric wires and cables, and casings of electronic parts, and daily necessities such as containers, bags, shoes, furniture, toys, and sports goods. More specifically, it can be applied to the base mat of a solar power generation device.

[0085] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments. Also, the effects described in the above embodiments are merely an enumeration 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 embodiments. Further, the above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

Explanation of Signs

[0086] 1 Manufacturing system 2 Cutting device 12 Coarse crusher 13 Fine crusher 14 Cache silo 15 Crusher 16 Specific gravity separator 17 Powder polishing and sorting device 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 ship's 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; 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; and the crushing step is a step of crushing the substantially plate-shaped member in multiple stages to make the final average particle diameter of the crushed material 10 μm or more and 50 μm or less.

2. The crushing step is a first crushing step of crushing the substantially plate-shaped member so that the average particle diameter 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 diameter 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 diameter becomes 10 μm or more and 50 μm or less. The method for producing a recycled fiber-reinforced resin according to claim 1, comprising the above steps.

3. A method for producing a recycled resin composition, comprising a kneading and molding step having an extruder or a compressor after kneading a kneading object containing at least 20% by mass or more and 30% by mass or less of a 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.

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 contains at least one resin used in at least one selected from a wind power plant, a bathroom, and a ship's 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 including a shovel body moved by a traveling crawler and an arm provided on the shovel body; a cutting mechanism detachably provided at a tip of the arm for cutting a waste plastic material into a predetermined size; a water spraying mechanism for spraying water on 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 has a plurality of cutting blades provided at a separation width of the predetermined size for cutting the waste plastic material; and a drive mechanism for rotationally driving the cutting blades by hydraulic pressure. The cutting device is provided with the above components.

8. A crushing mechanism for crushing raw materials, a feeder mechanism for feeding the raw materials to the crushing mechanism in a fixed quantity, a cyclone collector mechanism for collecting powder materials formed by crushing the raw materials by the crushing mechanism by an air flow, and has the crushing mechanism is 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, having a blade member for cutting the raw materials and a polishing portion formed on the side surface of the blade member for polishing the raw materials, a rotation drive mechanism connected to the rotation axis of the rotating body for rotationally driving the rotating body at a high speed A crushing and polishing device.

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, having an average particle diameter of 10 μm or more and 50 μm or less.

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

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

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