Carbon fiber bundle regeneration method and carbon fiber bundle regeneration device

Abstract

A method for regenerating a carbon fiber bundle from a structure having: a hollow base material; and a carbon fiber reinforced resin layer comprising a matrix resin and a carbon fiber bundle aggregate composed of a plurality of carbon fiber bundles and wound around the hollow base material, furthermore, the method for regenerating the carbon fiber bundle includes: a first heating step of heating the structure to decompose a portion of the matrix resin; an unwinding step for unwinding the carbon fiber bundle aggregate, to which the decomposition residue of the matrix resin has adhered, from the carbon fiber-reinforced resin layer in which a part of the matrix resin has been decomposed; a dividing step for dividing the unwound carbon fiber bundle aggregate into a plurality of intermediate carbon fiber bundles to which decomposition residues of the matrix resin adhere; a second heating step for obtaining a plurality of regenerated carbon fiber bundles by heating the plurality of divided intermediate carbon fiber bundles and decomposing the decomposition residue of the matrix resin; and a winding step for winding the plurality of regenerated carbon fiber bundles.

Description

Technical Field

[0001] The present invention relates to a method for regenerating a carbon fiber bundle, a device for regenerating a carbon fiber bundle, and a carbon fiber bundle. Background Art

[0002] In recent years, through prevention, reduction, recycling, and reuse of waste generation, efforts have been actively made to significantly reduce waste generation. To achieve this goal, research and development on methods for recovering carbon fibers from carbon fiber reinforced resins have been carried out.

[0003] Patent Document 1 describes a method for recycling carbon fibers, including the following steps: a step of thermally decomposing the resin in a carbon fiber reinforced resin molded product by first heat treatment; and a step of pulling out and winding the carbon fibers from the carbon fiber reinforced resin molded product after the first heat treatment. At this time, the winding step includes: a step of thermally decomposing the resin residue attached to the carbon fibers by second heat treatment; and a step of applying a sizing agent to the carbon fibers after the second heat treatment. In addition, the carbon fiber reinforced resin molded product is a can having a liner and a carbon fiber reinforced resin layer.

[0004] [Prior Art Documents]

[0005] (Patent Document)

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-15366 Summary of the Invention

[0007] [Problems to be Solved by the Invention]

[0008] However, when a carbon fiber bundle aggregate composed of a plurality of carbon fiber bundles is wound around a liner, if the carbon fiber recycling method of Patent Document 1 is applied, the carbon fibers constituting adjacent carbon fiber bundles will be entangled with each other when the resin residue attached to the carbon fibers is thermally decomposed by the second heat treatment. Therefore, it is impossible to equally divide the plurality of carbon fiber bundles constituting the carbon fiber bundle aggregate into the original number of roots for recycling.

[0009] An object of the present invention is to provide a method for regenerating a carbon fiber bundle and a device for regenerating a carbon fiber bundle, which can equally divide the plurality of carbon fiber bundles constituting a carbon fiber bundle aggregate into the original number of roots for regeneration even when the carbon fiber bundle aggregate composed of a plurality of carbon fiber bundles is wound around a hollow substrate.

[0010] [Technical Means for Solving the Problems]

[0011] (1) A method for regenerating a carbon fiber bundle, which is a method for regenerating a carbon fiber bundle from a structure. The structure has: a hollow substrate; and a carbon fiber reinforced resin layer, which includes a carbon fiber bundle aggregate composed of a plurality of carbon fiber bundles and wound around the aforementioned hollow substrate, and a matrix resin. And the method for regenerating the carbon fiber bundle includes: a first heating step of heating the aforementioned structure to decompose a part of the aforementioned matrix resin; an unwinding step of unwinding the carbon fiber bundle aggregate with decomposition residues of the aforementioned matrix resin attached from the carbon fiber reinforced resin layer after a part of the aforementioned matrix resin is decomposed; a dividing step of dividing the unwound carbon fiber bundle aggregate into a plurality of intermediate carbon fiber bundles with decomposition residues of the aforementioned matrix resin attached; a second heating step of heating the plurality of divided intermediate carbon fiber bundles to decompose the decomposition residues of the aforementioned matrix resin, thereby obtaining a plurality of regenerated carbon fiber bundles; and a winding step of winding the plurality of regenerated carbon fiber bundles.

[0012] (2) The method for regenerating a carbon fiber bundle according to (1), wherein, in the aforementioned dividing step, the plurality of intermediate carbon fiber bundles are supported by a plurality of tensioners.

[0013] (3) The method for regenerating a carbon fiber bundle according to (2), wherein the aforementioned tensioner has two leaf springs for clamping the aforementioned intermediate carbon fiber bundle.

[0014] (4) The method for regenerating a carbon fiber bundle according to (2) or (3), wherein the plurality of tensioners are arranged at a prescribed distance apart.

[0015] (5) The method for regenerating a carbon fiber bundle according to (4), wherein, in the aforementioned carbon fiber bundle aggregate, a plurality of carbon fiber bundles are arranged side by side in the width direction, the end portions in the width direction of the side-by-side arranged carbon fiber bundles alternately overlap each other, and the plurality of tensioners are arranged in such a manner as to move the overlapping end portions of the carbon fiber bundles away from each other.

[0016] (6) The method for regenerating a carbon fiber bundle according to any one of (1) to (5), wherein, after temporarily placing the unwound carbon fiber bundle aggregate, it is divided into the plurality of intermediate carbon fiber bundles.

[0017] (7) A regeneration device for carbon fiber bundles is a device for regenerating carbon fiber bundles from a structure. The structure has: a hollow substrate; and a carbon fiber reinforced resin layer, which includes a carbon fiber bundle aggregate composed of a plurality of carbon fiber bundles and wound around the aforementioned hollow substrate and a matrix resin. And the regeneration device for carbon fiber bundles has: a first heating part that heats the aforementioned structure to decompose a part of the aforementioned matrix resin; an unwinding part that unwinds the carbon fiber bundle aggregate with the decomposition residue of the aforementioned matrix resin attached from the carbon fiber reinforced resin layer after a part of the aforementioned matrix resin is decomposed; a dividing part that divides the unwound carbon fiber bundle aggregate into a plurality of intermediate carbon fiber bundles with the decomposition residue of the aforementioned matrix resin attached; a second heating part that heats the plurality of divided intermediate carbon fiber bundles to decompose the decomposition residue of the aforementioned matrix resin, thereby obtaining a plurality of regenerated carbon fiber bundles; and a winding part that winds the plurality of regenerated carbon fiber bundles.

[0018] (8) A regenerated carbon fiber bundle is regenerated by the method for regenerating carbon fiber bundles according to any one of (1) to (6).

[0019] (Advantages of the Invention)

[0020] According to the present invention, a method for regenerating carbon fiber bundles and a regeneration device for carbon fiber bundles can be provided, which can evenly divide a plurality of carbon fiber bundles constituting a carbon fiber bundle aggregate into the original number of roots for regeneration even when the carbon fiber bundle aggregate composed of a plurality of carbon fiber bundles is wound around a hollow substrate. Description of the Drawings

[0021] Figure 1 It is a cross-sectional view showing an example of a high-pressure hydrogen tank.

[0022] Figure 2 It is a cross-sectional view showing an example of a carbon fiber bundle aggregate.

[0023] Figure 3 It is a view showing an example of the first heating part used in the first heating process.

[0024] Figure 4 It is shown in Figure 3 a view of a rotating part that rotates a high-pressure hydrogen tank in a heat treatment chamber.

[0025] Figure 5 It is a front view showing an example of the unwinding part used in the unwinding process.

[0026] Figure 6 It is a side view showing an example of the unwinding part and the dividing part used in the unwinding process and the dividing process.

[0027] Figure 7 It is shown in Figure 6Stereogram of the tensioner.

[0028] Figure 8 It is to illustrate Figure 6 Schematic diagram of the configuration of the tensioner.

[0029] Figure 9 It is to show Figure 6 Side view of a modified example of the dividing portion.

[0030] Figure 10 It is a schematic diagram showing an example of the second heating portion, the gluing portion, and the winding portion used in the second heating process, the gluing process, and the winding process. Detailed implementation mode

[0031] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0032] A method for regenerating a carbon fiber bundle according to an embodiment of the present invention is a method for regenerating a carbon fiber bundle from a structure, the structure having: a hollow substrate; and a carbon fiber reinforced resin layer including a carbon fiber bundle aggregate composed of a plurality of carbon fiber bundles and wound around the hollow substrate and a matrix resin. As the structure, there is no particular limitation, and for example, known high-pressure hydrogen tanks (type 2 to 4) can be cited.

[0033] As the carbon fiber constituting the carbon fiber bundle, there is no particular limitation, and for example, polyacrylonitrile (PAN) - based carbon fiber, pitch - based carbon fiber can be cited. Here, the carbon fiber constituting the carbon fiber bundle is a long fiber. The fiber length of the carbon fiber is not particularly limited, for example, it is 1 m or more. As the matrix resin, there is no particular limitation, and for example, thermosetting resins such as epoxy resin, thermoplastic resins can be cited.

[0034] Figure 1 An example of a high - pressure hydrogen tank is shown in

[0035] The high - pressure hydrogen tank T has a liner L as a hollow substrate, a carbon fiber reinforced resin layer F including a carbon fiber bundle aggregate wound around the liner L and a matrix resin, and interfaces C1, C2 provided at both ends in the longitudinal direction. As the material constituting the liner L, there is no particular limitation, and for example, metals such as aluminum and chromium - molybdenum steel, resins such as polyamide and polyethylene can be cited.

[0036] As a manufacturing method of the high - pressure hydrogen tank T, there is no particular limitation, and for example, the filament winding method can be cited.

[0037] Figure 2 An example of the carbon fiber bundle aggregate is shown in

[0038] In the carbon fiber bundle aggregate A, a plurality of carbon fiber bundles B are arranged side by side in the width direction. At this time, the end portions in the width direction of the carbon fiber bundles B arranged side by side overlap each other alternately.

[0039] A method for regenerating carbon fiber bundles according to an embodiment of the present invention includes: a first heating step of heating a high-pressure hydrogen tank T to decompose a part of the matrix resin; an unwinding step of unwinding an intermediate carbon fiber bundle aggregate I1 having decomposition residues of the matrix resin attached thereto from the carbon fiber reinforced resin layer after a part of the matrix resin is decomposed; and a splitting step of splitting the unwound intermediate carbon fiber bundle aggregate I1 into a plurality of intermediate carbon fiber bundles I2 having decomposition residues of the matrix resin attached thereto. In addition, a method for regenerating carbon fiber bundles according to an embodiment of the present invention further includes: a second heating step of heating the plurality of split intermediate carbon fiber bundles I2 to decompose the decomposition residues of the matrix resin, thereby obtaining a plurality of regenerated carbon fiber bundles R; and a winding step of winding the plurality of regenerated carbon fiber bundles R. Therefore, the carbon fibers of the overlapping carbon fiber bundles constituting the intermediate carbon fiber bundle aggregate I1 do not entangle with each other. As a result, the plurality of carbon fiber bundles B constituting the carbon fiber bundle aggregate A are equally divided into the original number of roots and regenerated. In addition, since heating of the plurality of split intermediate carbon fiber bundles I2 can be promoted, the processing time of the second heating step can be shortened.

[0040] The first heating step preferably includes: a first step of decomposing the matrix resin at a temperature equal to or higher than the thermal decomposition start temperature of the matrix resin and lower than the flash point of the thermal decomposition gas of the matrix resin; and a second step of decomposing the matrix resin decomposed in the first step at a temperature equal to or higher than the thermal oxidative decomposition start temperature of the decomposition residue of the matrix resin and lower than the thermal decomposition start temperature of the carbon fiber. Thereby, overheating caused by combustion of the thermal decomposition gas of the matrix resin and deterioration of the carbon fiber can be suppressed.

[0041] When the matrix resin is an epoxy resin, for example, in the first step, heating is performed at a temperature of 330°C or higher and 360°C or lower, and in the second step, heating is performed at a temperature of 430°C or higher and 470°C or lower. In this case, as the thermal decomposition gas, for example, bisphenol A, phenol, etc. can be cited.

[0042] In addition, regarding the heating temperature in the first heating step, there is no particular limitation as long as the carbon fiber bundle to which the decomposition residue of the matrix resin is attached to the carbon fiber can be unwound.

[0043] Figure 3 A heat treatment furnace is shown as an example of the first heating unit used in the first heating step.

[0044] The heat treatment furnace 10 has a heat treatment chamber 11 and a combustion chamber 12.

[0045] The heat treatment chamber 11 is a sealed space surrounded by an outer wall 11a and an inner wall 11b. In addition, in the figure, burners 11c are provided at the upper part of the left outer wall 11a and the lower part of the right outer wall 11a of the heat treatment chamber 11 in such a way that combustion gas flows into the inner wall 11b. Therefore, when the gas fuel and air are mixed and burned using the burners 11c, the combustion gas convects within the inner wall 11b, thereby stabilizing the temperature within the inner wall 11b.

[0046] In the heat treatment chamber 11, a sealed door for accommodating the high-pressure hydrogen tank T is provided in a part of the outer wall 11a and the inner wall 11b. Here, the high-pressure hydrogen tank T is placed on a heat insulating material 11d, and the heat insulating material 11d is provided in such a way as to penetrate the bottom surface of the inner wall 11b. In addition, a load sensor 11e as a mass detection unit is provided between the bottom surface of the outer wall 11a and the heat insulating material 11d, and the mass of the high-pressure hydrogen tank T is detected in real time based on the strain. Thereby, the heating conditions in the heat treatment chamber 11 are optimized. Therefore, the variation in the decomposition amount of the matrix resin caused by individual differences in the materials, shapes, etc. of the high-pressure hydrogen tank T can be suppressed, thereby improving the management accuracy. In addition, the heating time in the heat treatment chamber 11 does not need to be overly extended, so it helps to shorten the heating time and reduce the energy consumption.

[0047] In addition, the mass detection unit can also detect the reduction amount of the mass of the high-pressure hydrogen tank T in real time. In addition, the mass detection unit can be omitted as needed.

[0048] In the figure, the decomposition gas of the matrix resin generated within the inner wall 11b is discharged from the exhaust port 11f formed in the upper part of the inner wall 11b, and then is introduced into the combustion chamber 12 through a pipe 11g provided through the outer wall 11a.

[0049] The combustion chamber 12 is a sealed space surrounded by an outer wall 12a and an inner wall 12b. In addition, in the figure, a burner 12c is provided at the central part of the left outer wall 12a of the combustion chamber 12 in such a way that combustion gas flows into the inner wall 12b. On the other hand, after passing through the outer wall 12a, the pipe 11g penetrates both the inside and outside of the inner wall 12b within the outer wall 12a, and finally, in the figure, is connected to the upper left part of the inner wall 12b. At this time, the decomposition gas of the matrix resin is heated by the combustion gas flowing within the inner wall 12b during the period of passing through the pipe 11g within the inner wall 12b, and then is introduced from the upper left part of the inner wall 12b and contacts the combustion gas. Thereby, after the decomposition gas of the matrix resin burns, it is exhausted to the outside from the exhaust port 12d.

[0050] Figure 4 An example of a rotating part for rotating the high-pressure hydrogen tank T within the heat treatment chamber 11 is shown. In addition, Figure 4(a) and (b) are a sectional view and a side view, respectively.

[0051] The rotation axis 21 in the substantially horizontal direction of the rotating part 20 penetrates the wall part W of the heat treatment chamber 11. Therefore, in the figure, the temperature distribution of the carbon fiber reinforced resin layer F in the vertical direction is homogenized.

[0052] In addition, the rotation axis 21 can also be in a direction other than the substantially horizontal direction. For example, it can also be in the substantially vertical direction. If the rotation axis 21 is in the substantially vertical direction, the temperature distribution of the carbon fiber reinforced resin layer F in the heat treatment chamber 11 will be homogenized to the same extent as when the rotation axis 21 is in the substantially horizontal direction.

[0053] The high-pressure hydrogen tank T is connected to the rotation axis 21 via a flanged jig 22 and a rotary shaft flange 23 that utilize the shapes of the interfaces C1 and C2. At this time, the flanged jig 22 and the rotary shaft flange 23 are fixed by bolts and nuts, for example. In addition, the high-pressure hydrogen tank T is placed on a base 24, and a bearing 25 is provided on the base 24. Further, a heat insulating material 26 is provided inside the wall part W of the heat treatment furnace 10. In addition, a motor for rotating the rotation axis 21 is provided outside the wall part W of the heat treatment furnace 10, and a cooling jacket 27 is provided around the rotation axis 21.

[0054] Figure 5 An example of a unwinding part used in the unwinding process is shown. In addition, Figure 6 An example of an unwinding part and a dividing part used in the unwinding process and the dividing process is shown.

[0055] The unwinding part 30 has: a rotary jig 31 that supports the high-pressure hydrogen tank T1 after decomposing a part of the matrix resin so as to be rotatable; and a motor 32 that rotates the high-pressure hydrogen tank T1. The rotational power of the motor 32 is transmitted to the rotary jig 31 via a belt 33. As a result, the intermediate carbon fiber bundle aggregate I1 is unwound via rollers 34 and 35. At this time, the roller 34 is arranged so that the intermediate carbon fiber bundle aggregate I1 is unwound outside the tangent line at the position of the unwound intermediate carbon fiber bundle aggregate I1 of the high-pressure hydrogen tank T1. In addition, the rollers 34 and 35 are long shafts to cope with the unwinding of the intermediate carbon fiber bundle aggregate I1 in the longitudinal direction of the high-pressure hydrogen tank T1. Further, a dancer roller 36 for controlling the unwinding tension is provided to absorb the difference in the unwinding amount per revolution caused by the circumferential winding and the helical winding of the intermediate carbon fiber bundle aggregate I1.

[0056] In addition, a blade can be provided instead of the roller 34.

[0057] The dividing unit 100 includes: a plurality of tensioners 101 that divide the unwound intermediate carbon fiber bundle aggregate I1 into a plurality of intermediate carbon fiber bundles I2 to which decomposition residues of the matrix resin are attached, and support the plurality of intermediate carbon fiber bundles I2; and a roller 102 that conveys the plurality of intermediate carbon fiber bundles I2. Therefore, in the winding process, not only is the torque applied to the recycled carbon fiber bundle R less likely to be transmitted to the high-pressure hydrogen tank T1, but also the tension of the intermediate carbon fiber bundles I2 in the second heating process can be adjusted. The tensioner 101, as Figure 7 shown, is a spring tensioner having two leaf springs 111 that clamp the intermediate carbon fiber bundle I2. As a commercially available product of the spring tensioner, for example, Spring Leaf Yarn Tensioner (manufactured by Ascotex) can be cited. Here, the plurality of tensioners 101, as Figure 8 shown, are arranged in such a way that the overlapping ends of the carbon fiber bundles B constituting the unwound intermediate carbon fiber bundle aggregate I1 are separated from each other. That is, in the figure, the tensioner 101 corresponding to the carbon fiber bundle B arranged on the upper side is arranged on the upper side of the intermediate carbon fiber bundle aggregate I1, and in the figure, the tensioner 101 corresponding to the carbon fiber bundle B arranged on the lower side is arranged on the lower side of the intermediate carbon fiber bundle aggregate I1. Therefore, the unwound intermediate carbon fiber bundle aggregate I1 is divided into a plurality of intermediate carbon fiber bundles I2.

[0058] In addition, if the carbon fiber bundle aggregate has a structure composed of a plurality of carbon fiber bundles, the plurality of carbon fiber bundles may not be arranged side by side in the width direction. For example, in the carbon fiber bundle aggregate, the plurality of carbon fiber bundles may be laminated in the thickness direction. At this time, the tensioner is arranged according to the arrangement of the carbon fiber bundles constituting the carbon fiber bundle aggregate.

[0059] The dividing unit 100 may also have a buffer portion for temporarily placing the unwound intermediate carbon fiber bundle aggregate I1. Thereby, in the winding process, the torque applied to the recycled carbon fiber bundle R is less likely to be transmitted to the high-pressure hydrogen tank T1.

[0060] Figure 9 A modified example of the dividing unit 100 is shown in

[0061] The dividing unit 100A has the same structure as the dividing unit 100 except that the plurality of tensioners 101 are arranged at a predetermined distance (for example, 10 cm) apart.

[0062] The heating temperature in the second heating process is preferably equal to or higher than the heating temperature in the first heating process. Thereby, the decomposition residues of the matrix resin attached to the intermediate carbon fiber bundle I2 are easily decomposed. On the other hand, the heating temperature in the second heating process is preferably equal to or lower than the thermal decomposition start temperature of the carbon fiber. Thereby, deterioration of the carbon fiber can be suppressed.

[0063] In addition, after the sizing process of sizing the recycled carbon fiber bundle R is performed, the sized recycled carbon fiber bundle R can be wound up.

[0064] Figure 10 An example of the second heating unit, sizing unit, and winding unit used in the second heating process, sizing process, and winding process is shown.

[0065] As the tubular furnace 40 of the second heating unit, heat insulation covers 42 are provided at both ends of the quartz tube 41. The heat insulation covers 42 are formed with through holes through which the intermediate carbon fiber bundle I2 attached with decomposition residues of the matrix resin can pass. In addition, in the central portion of the quartz tube 41 of the tubular furnace 40, a heating wire 43, a heat insulation material 44, and a protective cover 45 are sequentially provided. Therefore, by passing an electric current through the heating wire 43, the intermediate carbon fiber bundle I2 is heated, so that the decomposition residues of the matrix resin are decomposed, and thus the recycled carbon fiber bundle R can be obtained. At this time, not only can the temperature distribution in the tubular furnace 40 be made uniform, but also heating of parts other than the intermediate carbon fiber bundle I2 can be suppressed.

[0066] The sizing unit 50 allows the recycled carbon fiber bundle R to pass through the sizing liquid 51. At this time, the sizing liquid 51 is heated by the heater 52. In addition, by means of the roller 53, excessive coating of the sizing liquid 51 on the recycled carbon fiber bundle R can be prevented.

[0067] In addition, a drying furnace can be provided as needed to dry the recycled carbon fiber bundle R.

[0068] The feeding mechanism 60 includes feeding rollers 61, 62, and 63. By using the friction between the feeding rollers 61, 62, and 63 and the recycled carbon fiber bundle R, the linear speed of the recycled carbon fiber bundle R is controlled to a linear speed that is easy to manage the process.

[0069] The winding unit 70 includes: a winding motor 71 for winding the recycled carbon fiber bundle R around the paper core P; and a sliding roller 72 for laterally winding the recycled carbon fiber bundle R. At this time, by controlling the torque of the winding motor 71, the winding tension of the recycled carbon fiber bundle R can be controlled.

[0070] In addition, the recycled carbon fiber bundle R can be fibrillated, or multiple recycled carbon fiber bundles R can be combined. In addition, only the recycled carbon fiber bundle R derived from the carbon fiber bundle B that is not at both ends in the width direction of the carbon fiber bundle aggregate A among the multiple recycled carbon fiber bundles R can be wound as a long fiber. In this case, the recycled carbon fiber bundle R derived from the carbon fiber bundle B at both ends in the width direction of the carbon fiber bundle aggregate A can also be used as a short fiber.

[0071] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above embodiments, and the above embodiments can be appropriately changed within the scope of the gist of the present invention. For example, as a structure other than the high-pressure hydrogen tank, a drive shaft, a safety stopper, a low-friction roller, a rotor part of a main shaft motor, etc. can also be used.

[0072] Reference numeral

[0073] 100, 100A Dividing part

[0074] 101 Tensioner

[0075] 111 Leaf spring

[0076] A Carbon fiber bundle aggregate

[0077] B Carbon fiber bundle

[0078] C1, C2 Interfaces

[0079] F Carbon fiber reinforced resin layer

[0080] I1 Intermediate carbon fiber bundle aggregate

[0081] I2 Intermediate carbon fiber bundle

[0082] L Inner lining

[0083] R Recycled carbon fiber bundle

[0084] T, T1 High-pressure hydrogen tank

Claims

1. A method for regenerating a carbon fiber bundle, which is a method for regenerating a carbon fiber bundle from a structure, the structure having: a hollow substrate; And, a carbon fiber reinforced resin layer includes an aggregate of carbon fiber bundles composed of a plurality of carbon fiber bundles and wound around the hollow substrate, and a matrix resin; And, The method for regenerating the carbon fiber bundles includes: A first heating step of heating the above-mentioned structure to decompose a part of the above-mentioned matrix resin; An unwinding step of unwinding the aggregate of carbon fiber bundles with decomposition residues of the above-mentioned matrix resin attached from the carbon fiber reinforced resin layer after a part of the above-mentioned matrix resin is decomposed; A dividing step of dividing the unwound aggregate of carbon fiber bundles into a plurality of intermediate carbon fiber bundles with decomposition residues of the above-mentioned matrix resin attached; A second heating step of heating the plurality of divided intermediate carbon fiber bundles to decompose the decomposition residues of the above-mentioned matrix resin, thereby obtaining a plurality of regenerated carbon fiber bundles; and, A winding step of winding the plurality of regenerated carbon fiber bundles.

2. The regeneration method of the carbon fiber bundle according to claim 1, wherein, In the above-mentioned dividing step, the plurality of intermediate carbon fiber bundles are supported by a plurality of tensioners.

3. The regeneration method of the carbon fiber bundle according to claim 2, wherein, The above-mentioned tensioner includes two leaf springs for clamping the above-mentioned intermediate carbon fiber bundles.

4. The method for regenerating a carbon fiber bundle according to claim 2 or 3, wherein, The above-mentioned plurality of tensioners are arranged at a predetermined distance apart.

5. The regeneration method of the carbon fiber bundle according to claim 4, wherein, In the above-mentioned aggregate of carbon fiber bundles, a plurality of carbon fiber bundles are arranged side by side in the width direction, and the end portions in the width direction of the side-by-side arranged carbon fiber bundles alternately overlap each other. The above-mentioned plurality of tensioners are arranged in such a manner that the overlapping end portions of the above-mentioned carbon fiber bundles are separated from each other.

6. The method for regenerating a carbon fiber bundle according to any one of claims 1 to 3, wherein, After temporarily placing the unwound aggregate of carbon fiber bundles, it is divided into the above-mentioned plurality of intermediate carbon fiber bundles.

7. A regeneration device for a carbon fiber bundle, which is a device for regenerating a carbon fiber bundle from a structure, the structure having: a hollow substrate; And, a carbon fiber reinforced resin layer includes an aggregate of carbon fiber bundles composed of a plurality of carbon fiber bundles and wound around the hollow substrate, and a matrix resin; and, the regeneration device for the carbon fiber bundles has: A first heating unit that heats the above-mentioned structure to decompose a part of the above-mentioned matrix resin; An unwinding unit that unwinds the aggregate of carbon fiber bundles with decomposition residues of the above-mentioned matrix resin attached from the carbon fiber reinforced resin layer after a part of the above-mentioned matrix resin is decomposed; A dividing unit that divides the unwound aggregate of carbon fiber bundles into a plurality of intermediate carbon fiber bundles with decomposition residues of the above-mentioned matrix resin attached; A second heating unit that heats the plurality of divided intermediate carbon fiber bundles to decompose the decomposition residues of the above-mentioned matrix resin, thereby obtaining a plurality of regenerated carbon fiber bundles; And, A winding unit that winds the plurality of regenerated carbon fiber bundles.

8. A regenerated carbon fiber bundle regenerated by the method for regenerating carbon fiber bundles according to any one of claims 1 to 3.

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