Method for manufacturing carbon fiber sheet molding compound and apparatus for manufacturing carbon fiber sheet molding compound

Abstract

One of the main purposes of the present invention is to provide improvements relating to a method for manufacturing a carbon fiber sheet molding compound. The method of manufacturing a carbon fiber sheet molding compound includes: passing a continuous carbon fiber bundle drawn from a package through a guide tube and feeding the bundle to a chopper; unbundling the continuous carbon fiber bundle before the continuous carbon fiber bundle passes through the guide tube; forming a disordered felt by causing a chopped carbon fiber bundle generated by cutting the continuous carbon fiber bundle by the chopper to fall onto a traveling carrier film; and impregnating the disordered felt with a paste formed from a thermosetting resin composition.

Description

Technical Field

[0001] The present invention mainly relates to a method for manufacturing a carbon fiber sheet molding compound and an apparatus for manufacturing a carbon fiber sheet molding compound.

[0002] This application claims priority based on Japanese Patent Application No. 2023-2937 filed with the Japan Patent Office on January 12, 2023, and incorporates its content herein. Background Art

[0003] Carbon fiber reinforced plastic (CFRP) is a composite material using carbon fiber as a reinforcing material. Since CFRP is high-strength and lightweight, it has been used in recent years for components of various transportation equipment including automobiles, ships, railway vehicles, manned aircraft, and unmanned aircraft.

[0004] One of the intermediate materials used in the molding of CFRP products is a carbon fiber sheet molding compound (hereinafter also referred to as "CF-SMC").

[0005] CF-SMC is manufactured by forming a random mat from chopped carbon fiber bundles obtained by cutting a continuous carbon fiber bundle into shorter lengths, and impregnating the random mat with a paste of a thermosetting resin composition.

[0006] The following technique has been proposed: when manufacturing a composite material reinforced with chopped carbon fiber bundles, a continuous carbon fiber bundle before being cut by a chopper is processed with a roller having protrusions. If the continuous carbon fiber bundle is cut after being unraveled by this processing, a large number of chopped carbon fiber bundles having a bundle size smaller than that of the continuous carbon fiber bundle before cutting and having a high reinforcing effect are generated (Patent Document 1). The bundle size of a carbon fiber bundle refers to the number of carbon fiber filaments constituting the carbon fiber bundle (the same applies hereinafter).

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: U.S. Patent Application Publication No. 2012 / 0213997 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] One object of the present invention is to provide an improvement related to a method for manufacturing a carbon fiber sheet molding compound.

[0012] Another object of the present invention is to provide an improvement related to an apparatus for manufacturing a carbon fiber sheet molding compound.

[0013] The problems solved by the respective embodiments of the present invention are sometimes explicitly or implicitly disclosed in this specification.

[0014] Means for Solving the Problem

[0015] According to one aspect of the present invention, there is provided a method for manufacturing a carbon fiber sheet molding compound, which includes: passing a continuous carbon fiber bundle pulled out from a package through a guide tube and sending it to a chopper; performing a defibrillation treatment on the continuous carbon fiber bundle before passing it through the guide tube; causing short carbon fiber bundles generated by cutting the continuous carbon fiber bundle using the chopper to fall onto a traveling carrier film to form a random mat; and impregnating the random mat with a paste formed from a thermosetting resin composition.

[0016] According to another aspect of the present invention, there is provided a method for manufacturing a carbon fiber sheet molding compound, which includes: sending a continuous carbon fiber bundle pulled out from a package to a chopper; performing a defibrillation treatment on the continuous carbon fiber bundle before cutting it using the chopper; causing short carbon fiber bundles generated by cutting the continuous carbon fiber bundle using the chopper to fall onto a traveling carrier film to form a random mat; and impregnating the random mat with a paste formed from a thermosetting resin composition, wherein the moving distance of the continuous carbon fiber bundle from undergoing the defibrillation treatment to being cut by the chopper exceeds 3 m.

[0017] According to still another aspect of the present invention, there is provided a method for manufacturing a carbon fiber sheet molding compound, which includes: causing short carbon fiber bundles generated by cutting a continuous carbon fiber bundle using a chopper to fall onto a traveling carrier film to form a random mat; impregnating the random mat with a paste formed from a thermosetting resin composition; performing a defibrillation treatment on the continuous carbon fiber bundle before cutting it using the chopper; and dispersing the short carbon fiber bundles using a dispersing roller driven to rotate before they fall onto the carrier film.

[0018] According to still another aspect of the present invention, there is provided a method for manufacturing a carbon fiber sheet molding compound, which includes: causing short carbon fiber bundles generated by cutting a continuous carbon fiber bundle using a chopper to fall onto a traveling carrier film to form a random mat; impregnating the random mat with a paste formed from a thermosetting resin composition; and dividing the space where the short carbon fiber bundles fall toward the carrier film into a plurality of regions along the T direction by at least one partition, wherein the at least one partition is formed of metal and grounded.

[0019] According to still another aspect of the present invention, there is provided a manufacturing apparatus for a carbon fiber sheet molding compound, which includes a chopper, a guide tube, and a defibrillator, wherein the chopper is disposed above the traveling path of a carrier film, the guide tube is for allowing a continuous carbon fiber bundle pulled out from a package and sent to the chopper to pass through, and the defibrillator is disposed at a position more upstream than the guide tube to defibrillate the continuous carbon fiber bundle.

[0020] According to another aspect of the present invention, there is provided a manufacturing apparatus for a carbon fiber sheet molding compound, which includes a shredder and a fiber opener. The shredder is disposed above the traveling path of the carrier film, and the fiber opener is configured to untangle a continuous carbon fiber bundle that is pulled out from a package and sent to the shredder. The distance from the fiber opener to the shredder along the traveling path of the continuous carbon fiber bundle exceeds 3 m.

[0021] According to another aspect of the present invention, there is provided a manufacturing apparatus for a carbon fiber sheet molding compound, which includes: a shredder, a fiber opener, and a dispersing roller that is rotationally driven. The shredder is disposed above the traveling path of the carrier film, the fiber opener is configured to untangle a continuous carbon fiber bundle that is sent to the shredder, and the rotationally driven dispersing roller is configured to disperse the chopped carbon fiber bundles generated by cutting the continuous carbon fiber bundles using the shredder.

[0022] According to another aspect of the present invention, there is provided a manufacturing apparatus for a carbon fiber sheet molding compound, which includes a shredder and at least one partition. The shredder is disposed above the traveling path of the carrier film, and the at least one partition is formed of metal and grounded. The space where the chopped carbon fiber bundles fall toward the traveling path is divided into a plurality of regions along the T direction by the at least one partition, and the chopped carbon fiber bundles are generated by cutting continuous carbon fiber bundles using the shredder.

[0023] Advantages of the Invention

[0024] According to a preferred embodiment, improvements related to a manufacturing method or a manufacturing apparatus for a carbon fiber sheet molding compound are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Figure 1 Shows the configuration of a CF-SMC manufacturing apparatus according to an embodiment.

[0026] Figure 2 Figure 2 Shows an example of a roller with protrusions.

[0027] Figure 3 Figure 3 Shows a situation where a continuous carbon fiber bundle is engaged by a pair of gears composed of two meshing spur gears.

[0028] Figure 4 Figure 4 Shows a situation where the interval between the two gears constituting the pair of gears is widened to allow the joint portion between the continuous carbon fiber bundles to pass through.

[0029] Figure 5 Figure 5 Shows a fiber opener configured to make the continuous carbon fiber bundles processed once by a pair of gears into only one bundle.​​​​​​​​​​

[0030] Figure 6 Figure 6 Shows the structure of the shredder.

[0031] Figure 7 Figure 7 Shows an example of the pin roll.

[0032] Figure 8 Figure 8 Shows an example of the cage roll, showing the cage roll as viewed from a direction parallel to the rotation axis.

[0033] Figure 9 Figure 9 Shows the case of observing the cage roll Figure 8 from a direction perpendicular to the rotation axis.

[0034] Figure 10 Figure 10 Shows the case of setting compartments and configuring the main part of the pin roll type dispersion roll therein. The traveling direction of the first carrier film is from left to right within the plane of the paper.

[0035] Figure 11 Figure 11 Shows the case of setting compartments and configuring the main part of the pin roll type dispersion roll therein. The traveling direction of the first carrier film is from the back of the paper toward the front.

[0036] Figure 12 Figure 12 Shows the case where the space where the short carbon fiber bundles produced by cutting the continuous carbon fiber bundles by the shredder fall is divided into a plurality of regions along the T direction by a partition plate disposed below the shredder. The traveling direction of the first carrier film is from the back of the paper toward the front. Detailed implementation mode

[0037] Hereinafter, several embodiments of the present invention will be described with appropriate reference to the drawings. The dimensional ratios in the drawings are dimensional ratios for ease of explanation and are sometimes different from the actual dimensional ratios. In addition, the same components in the drawings are denoted by the same reference numerals, and sometimes the description of the repeated components is omitted.

[0038] 1. Method and apparatus for manufacturing CF-SMC

[0039] The manufacturing of CF-SMC using the manufacturing method of one embodiment of the present invention can be carried out, for example, using Figure 1 the manufacturing apparatus showing the basic configuration in.

[0040] Figure 1 ​​​​​​​​​​​​​​The CF-SMC manufacturing apparatus 70 shown includes a beam breaker BL, a guide tube GT, guide rollers GR, a chopper 1, a first coater 2a, a second coater 2b, and an impregnator 3.

[0041] The chopper 1 is disposed above the traveling path of the first carrier film 51. When the first carrier film 51 travels below the chopper 1, its surface is held horizontal.

[0042] In this specification, the direction orthogonal to the traveling direction of the first carrier film and horizontal is sometimes referred to as the T direction.

[0043] In Figure 1 it, the T direction is perpendicular to the paper surface.

[0044] Taking the case of using the Figure 1 shown manufacturing apparatus as an example, the manufacturing method of the CF-SMC of the preferred embodiment will be described as follows.

[0045] First, a continuous carbon fiber bundle 10 is pulled out from the package P. The package P may or may not use a bobbin.

[0046] The bundle size of the continuous carbon fiber bundle 10 is usually 12K or more, and may be 15K or more, 18K or more, 24K or more, 36K or more, 40K or more, 48K or more, etc. There is no particular upper limit to the bundle size of the continuous carbon fiber bundle 10, and it may be 200K or less, 150K or less, 100K or less, 80K or less, 60K or less, etc. Here, K is a symbol representing 1000. For example, 12K represents 12,000, 48K represents 48,000, and 100K represents 100,000.

[0047] Before the continuous carbon fiber bundle 10 pulled out from the package P passes through the guide tube GT, it is unwound by the treatment performed by the beam breaker BL. Unwinding the carbon fiber bundle means weakening the bond between the carbon fiber filaments constituting the bundle. In the carbon fiber bundle, the carbon fiber filaments are mutually bonded to each other through a resin called sizing agent. Therefore, by applying mechanical force from the outside to partially break this bond, the carbon fiber bundle can be unwound.

[0048] The short carbon fiber bundles obtained by cutting the unwound continuous carbon fiber bundle contain a large number of short carbon fiber bundles with a small bundle size compared to the short carbon fiber bundles obtained by cutting the same continuous carbon fiber bundle without unwinding. This is because the unwound continuous carbon fiber bundle is easily divided into multiple bundles when cut.

[0049] As described in the aforementioned Patent Document 1, it is well known among those skilled in the art that the fine short carbon fiber bundles with a smaller bundle size have a high reinforcing effect when used for CFRP.

[0050] The unwinder of an example may also include a unit that pierces projections into a continuous carbon fiber bundle. A typical example of this unit is a roller with projections. As Figure 2 shown, the roller 11 with projections is a roller having a plurality of projections 12 disposed on its outer periphery. Preferred examples of the roller with projections include the roller described in the aforementioned Patent Document 1.

[0051] The circumferential speed of the outer periphery of the roller with projections is set, for example, in the range of 0.9 to 1.1 times the conveying speed of the continuous carbon fiber bundle so as to be substantially equal to the conveying speed of the continuous carbon fiber bundle.

[0052] The wrap angle of the continuous carbon fiber bundle on the roller with projections is preferably 30° or more, more preferably 60° or more, and still more preferably 90° or more. In order to reliably pierce the projections, sufficient tension is applied to the continuous carbon fiber bundle.

[0053] The arrangement pattern of the plurality of projections on the surface of the roller with projections preferably has periodicity in the circumferential direction and the axial direction. The circumferential period is preferably 10 mm or less, more preferably 5 mm or less. The axial period is preferably 5 mm or less, more preferably 3 mm or less. There is no particular lower limit for each period, and for example, it may be 1 mm or more.

[0054] A plurality of continuous carbon fiber bundles can be arranged in parallel with each other and supplied to one roller with projections, and the unwinding process can be performed simultaneously.

[0055] The unwinder may further include a unit that spreads the continuous carbon fiber bundle at a position upstream or downstream of the unit that pierces the projections into the continuous carbon fiber bundle. Examples of the unit that spreads the carbon fiber bundle include a spreading roller and a spreading rod.

[0056] The unwinder of an example may also include a gear pair composed of two meshing gears. The two gears are preferably spur gears. As Figure 3 shown, if the continuous carbon fiber bundle 10 is engaged by the gear pair 14 composed of two gears 13, 13, it bends at a smaller radius, so the bond between the filaments through the sizing agent is locally broken, and the continuous carbon fiber bundle is unwound. The gear pair only needs to rotate passively and does not need to be connected to a power source to rotate actively.

[0057] According to the method of using this gear pair, the continuous carbon fiber bundle can be bent at a smaller radius even without particularly applying tension. That is, the continuous carbon fiber bundle can be unwound simply without introducing a tension applying mechanism.

[0058] The materials of the two gears forming the gear pair can be polymers or metals. The tooth height (the difference between the root circle radius and the addendum circle radius) of each gear is, for example, 1 to 10 mm, or can also be 2 to 5 mm. The length obtained by dividing the circumferential length of the addendum circle of each gear by the number of teeth (the pitch of the teeth along the circumference of the addendum circle) is, for example, 1 mm to 10 mm, or can also be 3 mm to 7 mm. In one example, in each gear, the tooth height can be set to about 3.5 mm, and the length obtained by dividing the circumferential length of the addendum circle by the number of teeth can be set to about 5 mm.

[0059] By joining the terminal of the continuous carbon fiber bundle pulled out from one package to the start end of the continuous carbon fiber bundle pulled out from the next package to be used, it is possible to continuously manufacture CF-SMC without stopping the production line every time the package becomes empty. However, since the joint part between the continuous carbon fiber bundles is thicker than other parts, it cannot be engaged by the gear pair. Therefore, in a preferred example, as Figure 4 shown, it is also possible to only widen the interval between the two gears 13, 13 forming the gear pair 14 when the joint part 15 passes through.

[0060] As Figure 5 shown, preferably only one continuous carbon fiber bundle 10 is processed by one gear pair 14 at a time. Therefore, in order to simultaneously perform the unwinding process of N continuous carbon fiber bundles, it is preferable to provide at least N gear pairs on the unwinder. In this way, when only the joint part of 1 bundle out of the N bundles of continuous carbon fiber bundles passes through the unwinder at a certain timing, it is only necessary to widen the interval between the two gears forming the gear pair for processing this continuous carbon fiber bundle.

[0061] An unwinder in an example can also unwind the continuous carbon fiber bundle by applying sufficient tension to the continuous carbon fiber bundle and making it pass through a bending path formed by using rollers and / or rods. This unwinder can also have the function of spreading the carbon fiber bundle.

[0062] Since the space between the downstream end of the guide tube GT and the chopper 1 is limited, if an unwinder BL is provided here, not only is it inconvenient to adjust, maintain, inspect, repair, etc. the unwinder, but also the adjustment, maintenance, inspection, repair, etc. of the chopper become difficult.

[0063] In contrast, at a position more upstream than the guide tube GT, there is often more space available. Therefore, if an unwinder is arranged here, the adjustment, maintenance, inspection, repair, etc. of the unwinder BL are much easier. This is extremely important in the case of providing the same number of gear pairs as the number of bundles of continuous carbon fiber bundles to be processed in an unwinder that engages the continuous carbon fiber bundles with the gear pair.

[0064] In the process of unraveling a continuous carbon fiber bundle, it is difficult to cut the fiber filaments, so the problem of short carbon fiber filaments aggregating in the guide tube to form cotton debris will not become serious because a unbundler is provided at a position upstream of the guide tube.

[0065] The continuous carbon fiber bundle 10 unraveled by the unbundler BL passes through the guide tube GT and is sent to the chopper 1.

[0066] The material of the guide tube is not limited and can be a polymer or a metal. The length of the guide tube GT can be appropriately determined according to the distance from the installation location of the unbundler BL to the chopper 1.

[0067] In one example, the length of the guide tube can be 3 m or more, 5 m or more, or 7 m or more. This means that the moving distance of the continuous carbon fiber bundle 10 from being unbundled by the unbundler BL to being cut by the chopper 1, in other words, the distance from the unbundler BL to the chopper 1 along the traveling path of the continuous carbon fiber bundle 10, can exceed 3 m, further exceed 5 m, and further exceed 7 m.

[0068] There is no particular upper limit to the length of the guide tube, but in most cases, it is sufficient to be 15 m or less or 10 m or less. If the guide tube is too long, it is difficult to clean its interior.

[0069] As Figure 6 In one example shown in, the chopper 1 is composed of a support roller 22 that also serves as a conveying roller, a pinch roller 23, and a cutting roller 24. The outer periphery of the support roller 22 is formed of rubber. The continuous carbon fiber bundle 10 is cut by being pressed against the support roller 22 by a knife 25 mounted on the outer periphery of the cutting roller 24.

[0070] The fiber length of the carbon fibers contained in the chopped carbon fiber bundle 20 is, for example, in the range of 5 to 100 mm, preferably in the range of 5 to 60 mm, and more preferably in the range of 10 to 30 mm.

[0071] The chopped carbon fiber bundle 20 generated by cutting the continuous carbon fiber bundle 10 by the chopper 1 falls toward the traveling first carrier film 51. The falling chopped carbon fiber bundle 20 forms a random mat 30 on the first carrier film 51.

[0072] At a position upstream of the location where the chopped carbon fiber bundle 20 falls, a paste 41 of a thermosetting resin composition is coated on the upper surface of the first carrier film 51 by a first coater 2a. The viscosity of the paste is preferably adjusted to be in the range of 1 to 30 Pa·s at 25°C. On the second carrier film 52, a paste 42 having the same composition as the paste 41 is coated by a second coater 2b.

[0073] The first carrier film 51 and the second carrier film 52 are overlapped with each other in such a manner that the surfaces coated with the pastes 41 and 42 face each other with the random mat 30 therebetween, thereby forming a laminate 60.

[0074] After the laminate 60 is compressed by the impregnator 3, it is wound around a bobbin. In another example, the laminate 60 may be folded and stored in a container.

[0075] When the laminate 60 is compressed by the impregnator 3, the random mat 30 is impregnated with the pastes 41 and 42. After impregnation, the pastes thicken, thereby completing the CF-SMC. In order to make the CF-SMC have appropriate viscosity and hardness, a thickener is usually incorporated into the pastes 41 and 42. The amount of the thickener incorporated can be adjusted so that the pastes 41 and 42 do not thicken excessively before impregnation.

[0076] Examples of the materials of the first carrier film and the second carrier film include polyolefins such as polyethylene and polypropylene, polyvinylidene chloride, vinyl chloride, and polyamide. The first carrier film and the second carrier film may each be a multilayer film.

[0077] The first carrier film and the second carrier film may have a thickness in the range of 10 μm or more and 500 μm or less, for example. The first carrier film and the second carrier film may have a width in the range of 0.5 m or more and 1.5 m or less, for example.

[0078] In one example, a liquid epoxy resin, an epoxy curing agent, a thickener, and optional components are incorporated into a paste formed from a thermosetting resin composition. Examples of the optional components include a modifier composed of a rubber, an elastomer, or a thermoplastic resin in addition to a low shrinkage agent, an internal release agent, a colorant, a flame retardant, and an antioxidant.

[0079] In another example, at least one of a vinyl ester resin and an unsaturated polyester resin is incorporated together with a reactive diluent, a polymerization initiator, a thickener, and optional components into a paste containing a thermosetting resin composition. The reactive diluent is a liquid vinyl compound, and examples thereof include styrene and various (meth)acrylates. Examples of the optional components include a modifier composed of a rubber, an elastomer, or a thermoplastic resin in addition to a polymerization inhibitor, a low shrinkage agent, an internal release agent, a colorant, a flame retardant, and an antioxidant.

[0080] The manufacturing method of the CF-SMC described above may be further modified as described below.

[0081] In one modification example, it is also possible to disperse the chopped carbon fiber bundles using a dispersing roll driven to rotate and then let them fall onto the first carrier film. The rotation axis of the dispersing roll is preferably parallel to the T direction.

[0082] An example of the dispersing roll is a pin roll (also referred to as a spiked roll). As Figure 7As shown in one example, the main part 32 of the pin roll 31 has a structure in which a plurality of pins 34 project from the surface of the cylinder 33. The directions of the plurality of pins 34 are all perpendicular to the rotation axis. The shaft 35 passes through the center of the cylinder 33.

[0083] When the pin roll 31 is rotated, the pins 34 of the main part 32 strike the chopped carbon fiber bundles.

[0084] Another example of the dispersion roll is a cage roll. As Figure 8 and Figure 9 shown in one example, the main part 37 of the cage roll 36 has a structure in which a plurality of rods 39 are provided between a pair of disks 38, 38 sharing the rotation axis. The rods 39 can be replaced not only with rods having a non-circular cross-section such as square bars and flat bars, but also with pins and tensioned wires. The shaft 40 passes through the center of each disk.

[0085] When the cage roll is rotated, the rods of the main part strike the chopped carbon fiber bundles.

[0086] The dispersion roll common to the pin roll and the cage roll is characterized in that the shape of the main part has an n-fold rotational symmetry centered on the rotation axis (the central axis of the shaft), where n is an integer of 1 or more and finite. n is preferably 3 or more and 72 or less, and can be 45 or less, 36 or less, or 24 or less.

[0087] For example, in Figure 7 the pin roll 31 shown, n is 4, and in Figure 8 and Figure 9 the cage roll 36 shown, n is 6.

[0088] If it has this characteristic, even for rolls other than the pin roll and the cage roll, it is possible to physically strike the chopped carbon fiber bundles when they are rotated.

[0089] When using a rotating dispersion roll to disperse the chopped carbon fiber bundles, an effect of dividing the chopped carbon fiber bundles into smaller-sized carbon fiber bundles by physical striking can be obtained. If the continuous carbon fiber bundles are unraveled in advance before being cut by a shredder, this effect becomes more significant.

[0090] On the other hand, if the chopped carbon fiber bundles with weakened bonding between the fiber filaments are physically struck, fine carbon fiber dust that may float in the air is likely to be generated. To prevent the diffusion of this carbon fiber dust, as Figure 10 and Figure 11 shown, it is preferable to provide a partition 43 and dispose the main part of the dispersion roll 44 therein, and provide an opening in the ceiling of the partition, and guide the chopped carbon fiber bundles to the opening using a chute 45. Figure 10 The arrow X shown indicates the traveling direction of the first carrier film 51. Figure 11 The double arrow T shown indicates the T direction.

[0091] As Figure 11 in the example shown, the width of the compartment in the T direction is preferably narrower than the width of the first carrier film 51, but is not limited thereto.

[0092] Preferably, the end of the shaft of the dispersion roll projects outward from the compartment through an opening provided in the side wall of the compartment (the wall parallel to the traveling direction of the first carrier film). In Figure 11 the example of, the bearing 46 supporting the dispersion roll 44 is arranged outside the compartment 43, and substantially only the main part of the dispersion roll 44 is arranged in the compartment 43.

[0093] Furthermore, in order to suppress the leakage of carbon fiber dust outside the compartment, it is preferable to continuously remove carbon fiber dust from the inside of the compartment using a dust collector during the manufacture of CF-SMC. In Figure 10 the example of, the carbon fiber dust can be removed from the inside of the compartment 43 using a dust collector 49 connected to the compartment 43 via a hose 47. Although not limited, a preferred example of the dust collector is a dust collector equipped with a separator that separates dust from air using centrifugal force, that is, a cyclone dust collector. The suction port connected to the dust collector is preferably provided on either or both of the wall surface of the compartment and the inside of the compartment.

[0094] The removal of the carbon fiber dust leaked outside the compartment by the dust collector can also be carried out as needed.

[0095] As the reasons for preventing the diffusion of carbon fiber dust, the following reasons can be cited.

[0096] · Sometimes, the carbon fiber dust floats along with the air flow and then deposits at a specific location to form cotton debris. When the cotton debris is mixed into the random mat, it becomes a cause of poor impregnation.

[0097] · The carbon fiber dust will contaminate the mechanical elements of the SMC manufacturing apparatus and may hinder its operation.

[0098] · The carbon fiber dust will deteriorate the working environment inside the compartment where the SMC manufacturing apparatus is installed.

[0099] · The carbon fiber dust has conductivity, so it may hinder the operation of the electrical / electronic equipment attached to the SMC manufacturing apparatus and the electrical / electronic equipment used inside the compartment where the SMC manufacturing apparatus is installed.

[0100] In another modification, as Figure 12As shown, by at least one partition plate 48 disposed below the chopper 1, the space through which the short carbon fiber bundles generated by cutting the continuous carbon fiber bundles by the chopper 1 fall can be divided into a plurality of regions along the T direction. Using the partition plate to prevent the short carbon fiber bundles from moving in the T direction during their fall in this space is useful for making the unit area weight of the random mat formed on the first carrier film uniform along the T direction.

[0101] When the aforementioned dispersion roller is disposed below the chopper, by disposing a partition plate below the dispersion roller, the adverse effect of the air flow generated by the rotation of the dispersion roller on the uniformity of the unit area weight of the random mat can be reduced.

[0102] If fiber dust adheres to the partition plate under the action of static electricity, the adhered fiber dust may aggregate to form lint. To prevent this, it is preferable that the partition plate is formed of metal and grounded. Preferred examples of the metal include aluminum alloy and stainless steel, and aluminum alloy is more preferred from the aspect of high conductivity.

[0103] If the partition plate is damaged, the fiber dust is likely to be hooked on the damage, and then lint is likely to be formed. Since the aluminum alloy plate is easily damaged, electroless nickel plating may be performed to increase the surface hardness and make it difficult to be damaged.

[0104] 2. Summary of the Embodiments

[0105] In summary, the embodiments of the present invention include the following embodiments. However, it is not limited to these.

[0106] [Embodiment 1] A method for manufacturing a carbon fiber sheet molding compound, comprising: feeding a continuous carbon fiber bundle pulled out from a package through a guide tube and sending it to a chopper; performing a defibration treatment on the continuous carbon fiber bundle before passing through the guide tube; causing short carbon fiber bundles generated by cutting the continuous carbon fiber bundle by the chopper to fall onto a moving carrier film to form a random mat; and impregnating the random mat with a paste formed of a thermosetting resin composition.

[0107] [Embodiment 2] The manufacturing method according to Embodiment 1, wherein the defibration treatment includes piercing the continuous carbon fiber bundle with protrusions.

[0108] [Embodiment 3] The manufacturing method according to Embodiment 2, wherein a roller with protrusions is used in the defibration treatment.

[0109] [Embodiment 4] The manufacturing method according to any one of Embodiments 1 to 3, wherein the defibration treatment includes bending the continuous carbon fiber bundle.

[0110] [Embodiment 5] The manufacturing method according to Embodiment 4, wherein in the unbundling process, a gear pair is used, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

[0111] [Embodiment 6] The manufacturing method according to any one of Embodiments 1 to 5, wherein the chopped carbon fiber bundle is dispersed by a rotatably driven dispersion roll and then falls onto the carrier film.

[0112] [Embodiment 7] The manufacturing method according to Embodiment 6, further comprising: providing a compartment and disposing a main portion of the dispersion roll therein; and using a chute to guide the chopped carbon fiber bundle to an opening provided in the ceiling of the compartment.

[0113] [Embodiment 8] The manufacturing method according to Embodiment 6 or 7, further comprising: removing fiber dust generated thereby using a dust collector while dispersing the chopped carbon fiber bundle by the dispersion roll.

[0114] [Embodiment 9] The manufacturing method according to Embodiment 7, further comprising: removing fiber dust generated thereby using a dust collector while dispersing the chopped carbon fiber bundle by the dispersion roll; and the suction inlet connected to the dust collector is provided on either or both of the wall surface of the compartment and inside the compartment.

[0115] [Embodiment 10] The manufacturing method according to any one of Embodiments 1 to 9, further comprising: dividing the space where the chopped carbon fiber bundle falls toward the carrier film into a plurality of regions along the T direction by at least one partition.

[0116] [Embodiment 11] The manufacturing method according to Embodiment 10, wherein the at least one partition is formed of metal and grounded.

[0117] [Embodiment 12] The manufacturing method according to any one of Embodiments 1 to 11, wherein the length of the guiding tube is 3 m or more, and may be 5 m or more or 7 m or more.

[0118] [Embodiment 13] A manufacturing method of a carbon fiber sheet molding compound, comprising: feeding a continuous carbon fiber bundle pulled out from a package to a chopper; performing an unbundling process on the continuous carbon fiber bundle before cutting with the chopper; causing the chopped carbon fiber bundle generated by cutting the continuous carbon fiber bundle with the chopper to fall onto a traveling carrier film to form a random mat; and impregnating the random mat with a paste formed of a thermosetting resin composition, wherein the moving distance of the continuous carbon fiber bundle from the start of the unbundling process to the cutting with the chopper exceeds 3 m, exceeds 5 m, or exceeds 7 m.

[0119] [Embodiment 14] The manufacturing method according to Embodiment 13, wherein the unbundling process includes piercing the protrusions into the continuous carbon fiber bundle.

[0120] [Embodiment 15] The manufacturing method according to Embodiment 14, wherein a roller with protrusions is used in the unbundling process.

[0121] [Embodiment 16] The manufacturing method according to any one of Embodiments 13 to 15, wherein the unbundling process includes bending the continuous carbon fiber bundle.

[0122] [Embodiment 17] The manufacturing method according to Embodiment 16, wherein a gear pair is used in the unbundling process, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

[0123] [Embodiment 18] The manufacturing method according to any one of Embodiments 13 to 17, wherein the chopped carbon fiber bundle is dispersed by a dispersing roller driven to rotate and then falls onto the carrier film.

[0124] [Embodiment 19] The manufacturing method according to Embodiment 18, which further includes: providing a compartment and disposing a main part of the dispersing roller therein; and using a chute to guide the chopped carbon fiber bundle to an opening provided in the ceiling of the compartment.

[0125] [Embodiment 20] The manufacturing method according to Embodiment 18 or 19, which further includes: while dispersing the chopped carbon fiber bundle by the dispersing roller, removing fiber dust generated thereby by a dust collector.

[0126] [Embodiment 21] The manufacturing method according to Embodiment 19, which further includes: while dispersing the chopped carbon fiber bundle by the dispersing roller, removing fiber dust generated thereby by a dust collector; and an inhalation port connected to the dust collector is provided on either one or both of the wall surface of the compartment and inside the compartment.

[0127] [Embodiment 22] The manufacturing method according to any one of Embodiments 13 to 21, which further includes: dividing the space where the chopped carbon fiber bundle falls toward the carrier film into a plurality of regions along the T direction by at least one partition.

[0128] [Embodiment 23] The manufacturing method according to Embodiment 22, wherein the at least one partition is formed of metal and grounded.

[0129] [Embodiment 24] The manufacturing method according to any one of Embodiments 13 to 23, wherein the continuous carbon fiber bundle passes through a guiding tube and is sent to the chopper, and the defibrillation treatment is performed on the continuous carbon fiber bundle before it passes through the guiding tube.

[0130] [Embodiment 25] A manufacturing method of a carbon fiber sheet molding compound, comprising: dropping short carbon fiber bundles generated by cutting a continuous carbon fiber bundle using a chopper onto a traveling carrier film to form a random mat; impregnating the random mat with a paste formed from a thermosetting resin composition; performing a defibrillation treatment on the continuous carbon fiber bundle before cutting with the chopper; and dispersing the short carbon fiber bundles using a dispersing roller driven to rotate before dropping onto the carrier film.

[0131] [Embodiment 26] The manufacturing method according to Embodiment 25, further comprising: providing a compartment and disposing a main portion of the dispersing roller therein; and using a chute to guide the short carbon fiber bundles to an opening provided in the ceiling of the compartment.

[0132] [Embodiment 27] The manufacturing method according to Embodiment 25 or 26, further comprising: removing fiber dust generated therewith using a dust collector while dispersing the short carbon fiber bundles using the dispersing roller.

[0133] [Embodiment 28] The manufacturing method according to Embodiment 26, further comprising: removing fiber dust generated therewith using a dust collector while dispersing the short carbon fiber bundles using the dispersing roller; and an inhalation port connected to the dust collector is provided on either or both of the wall surface of the compartment and inside the compartment.

[0134] [Embodiment 29] The manufacturing method according to any one of Embodiments 25 to 28, wherein the defibrillation treatment includes piercing the continuous carbon fiber bundle with protrusions.

[0135] [Embodiment 30] The manufacturing method according to Embodiment 29, wherein a roller with protrusions is used in the defibrillation treatment.

[0136] [Embodiment 31] The manufacturing method according to any one of Embodiments 25 to 30, wherein the defibrillation treatment includes bending the continuous carbon fiber bundle.

[0137] [Embodiment 32] The manufacturing method according to Embodiment 31, wherein a gear pair is used in the defibrillation treatment, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

[0138] [Embodiment 33] The manufacturing method according to any one of Embodiments 25 to 32 further includes: dividing the space where the chopped carbon fiber bundles fall toward the carrier film into a plurality of regions along the T direction by at least one partition.

[0139] [Embodiment 34] The manufacturing method according to Embodiment 33, wherein the at least one partition is formed of metal and grounded.

[0140] [Embodiment 35] A manufacturing method of a carbon fiber sheet molding compound, which includes: dropping chopped carbon fiber bundles generated by cutting a continuous carbon fiber bundle with a chopper onto a traveling carrier film to form a random mat; impregnating the random mat with a paste formed of a thermosetting resin composition; and dividing the space where the chopped carbon fiber bundles fall toward the carrier film into a plurality of regions along the T direction by at least one partition, the at least one partition being formed of metal and grounded.

[0141] [Embodiment 36] The manufacturing method according to Embodiment 35, wherein the chopped carbon fiber bundles are dispersed by a rotatably driven dispersing roll and then dropped onto the carrier film.

[0142] [Embodiment 37] The manufacturing method according to Embodiment 36 further includes: providing a compartment and disposing a main portion of the dispersing roll and the at least one partition therein; and using a chute to guide the chopped carbon fiber bundles to an opening provided in a ceiling of the compartment.

[0143] [Embodiment 38] The manufacturing method according to Embodiment 36 or 37 further includes: removing fiber dust generated therewith by a dust collector while dispersing the chopped carbon fiber bundles by the dispersing roll.

[0144] [Embodiment 39] The manufacturing method according to Embodiment 37 further includes: removing fiber dust generated therewith by a dust collector while dispersing the chopped carbon fiber bundles by the dispersing roll; and a suction port connected to the dust collector is provided on either or both of a wall surface of the compartment and inside the compartment.

[0145] [Embodiment 40] The manufacturing method according to any one of Embodiments 35 to 39 further includes: performing a defibration treatment on the continuous carbon fiber bundle before cutting with the chopper.

[0146] [Embodiment 41] The manufacturing method according to Embodiment 40, wherein the defibration treatment includes piercing the continuous carbon fiber bundle with protrusions.

[0147] [Embodiment 42] The manufacturing method according to Embodiment 41, wherein a roll with protrusions is used in the defibration treatment.

[0148] [Embodiment 43] The manufacturing method according to any one of Embodiments 40 to 42, wherein the unbundling process includes bending the continuous carbon fiber bundle.

[0149] [Embodiment 44] The manufacturing method according to Embodiment 43, wherein a gear pair is used in the unbundling process, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

[0150] [Embodiment 45] A manufacturing apparatus for a carbon fiber sheet molding compound, comprising: a shredder disposed above a traveling path of a carrier film; a guiding tube for passing a continuous carbon fiber bundle pulled out from a package and sent to the shredder; and an unbundler disposed at a position more upstream than the guiding tube to unbundle the continuous carbon fiber bundle.

[0151] [Embodiment 46] The manufacturing apparatus according to Embodiment 45, wherein the unbundler includes a unit for piercing the continuous carbon fiber bundle with a protrusion.

[0152] [Embodiment 47] The manufacturing apparatus according to Embodiment 46, wherein the unbundler includes a roller with protrusions.

[0153] [Embodiment 48] The manufacturing apparatus according to any one of Embodiments 45 to 47, wherein the unbundler includes a unit for bending the continuous carbon fiber bundle.

[0154] [Embodiment 49] The manufacturing apparatus according to Embodiment 48, wherein the unbundler includes a gear pair composed of two gears that can be spur gears and mesh with each other.

[0155] [Embodiment 50] The manufacturing apparatus according to any one of Embodiments 45 to 49, further comprising a dispersing roller that is rotationally driven and is used to disperse the short carbon fiber bundles generated by cutting the continuous carbon fiber bundle with the shredder.

[0156] [Embodiment 51] The manufacturing apparatus according to Embodiment 50, wherein a main part of the dispersing roller is disposed in a compartment, and the manufacturing apparatus is provided with a chute for guiding the short carbon fiber bundles to an opening provided on a ceiling of the compartment.

[0157] [Embodiment 52] The manufacturing apparatus according to Embodiment 51, wherein a suction port connected to a dust collector is provided on one or both of a wall surface of the compartment and inside the compartment.

[0158] [Embodiment 53] The manufacturing apparatus according to any one of Embodiments 45 to 52, wherein a space where the chopped carbon fiber bundles fall toward the traveling path is divided into a plurality of regions along the T direction by at least one partition, and the chopped carbon fiber bundles are generated by cutting the continuous carbon fiber bundles using the chopper.

[0159] [Embodiment 54] The manufacturing apparatus according to Embodiment 53, wherein the at least one partition is formed of metal and grounded.

[0160] [Embodiment 55] The manufacturing apparatus according to any one of Embodiments 45 to 54, wherein the length of the guide tube is 3 m or more, and may be 5 m or more or 7 m or more.

[0161] [Embodiment 56] A manufacturing apparatus for a carbon fiber sheet molding compound, comprising: a chopper disposed above a traveling path of a carrier film; and a beam breaker for unraveling a continuous carbon fiber bundle pulled out from a package and sent to the chopper, and a distance from the beam breaker to the chopper along the traveling path of the continuous carbon fiber bundle exceeds 3 m, exceeds 5 m, or exceeds 7 m.

[0162] [Embodiment 57] The manufacturing apparatus according to Embodiment 56, wherein the beam breaker includes a unit for piercing the continuous carbon fiber bundle with a protrusion.

[0163] [Embodiment 58] The manufacturing apparatus according to Embodiment 57, wherein the beam breaker includes a roller with protrusions.

[0164] [Embodiment 59] The manufacturing apparatus according to any one of Embodiments 56 to 58, wherein the beam breaker includes a unit for bending the continuous carbon fiber bundle.

[0165] [Embodiment 60] The manufacturing apparatus according to Embodiment 59, wherein the beam breaker includes a gear pair formed of two gears that can be spur gears and mesh with each other.

[0166] [Embodiment 61] The manufacturing apparatus according to any one of Embodiments 56 to 60, further comprising a dispersing roller that is rotationally driven and is used for dispersing chopped carbon fiber bundles generated by cutting the continuous carbon fiber bundles using the chopper.

[0167] [Embodiment 62] The manufacturing apparatus according to Embodiment 61, wherein a main part of the dispersing roller is disposed in a compartment, and the manufacturing apparatus is provided with a chute for guiding the chopped carbon fiber bundles to an opening provided in a ceiling of the compartment.

[0168] [Embodiment 63] The manufacturing apparatus according to Embodiment 62, wherein a suction port connected to a dust collector is provided on either or both of the wall surface of the compartment and inside the compartment.

[0169] [Embodiment 64] The manufacturing apparatus according to any one of Embodiments 56 to 63, wherein a space where the chopped carbon fiber bundles fall along the traveling path is divided into a plurality of regions in the T direction by at least one partition, and the chopped carbon fiber bundles are produced by cutting the continuous carbon fiber bundle using the chopper.

[0170] [Embodiment 65] The manufacturing apparatus according to Embodiment 64, wherein the at least one partition is formed of metal and grounded.

[0171] [Embodiment 66] The manufacturing apparatus according to any one of Embodiments 56 to 65, further comprising a guide tube through which the continuous carbon fiber bundle sent to the chopper passes, and the unbundler is arranged at a position more upstream than the guide tube.

[0172] [Embodiment 67] A manufacturing apparatus for a carbon fiber sheet molding compound, comprising: a chopper arranged above a traveling path of a carrier film; an unbundler for unbundling a continuous carbon fiber bundle sent to the chopper; and a dispersing roller driven to rotate for dispersing chopped carbon fiber bundles produced by cutting the continuous carbon fiber bundle using the chopper.

[0173] [Embodiment 68] The manufacturing apparatus according to Embodiment 67, wherein the dispersing roller is arranged in a compartment, and the manufacturing apparatus is provided with a chute for guiding the chopped carbon fiber bundles to an opening provided in a ceiling of the compartment.

[0174] [Embodiment 69] The manufacturing apparatus according to Embodiment 68, wherein a suction port connected to a dust collector is provided on either or both of the wall surface of the compartment and inside the compartment.

[0175] [Embodiment 70] The manufacturing apparatus according to any one of Embodiments 67 to 69, wherein the unbundler includes a unit for piercing the continuous carbon fiber bundle with a protrusion.

[0176] [Embodiment 71] The manufacturing apparatus according to Embodiment 70, wherein the unbundler includes a roller with protrusions.

[0177] [Embodiment 72] The manufacturing apparatus according to any one of Embodiments 67 to 71, wherein the unbundling process includes a unit for bending the continuous carbon fiber bundle.

[0178] [Embodiment 73] The manufacturing apparatus according to Embodiment 72, wherein the unbundler includes a gear pair constituted by two gears that mesh with each other and can each be a spur gear.

[0179] [Embodiment 74] The manufacturing apparatus according to any one of Embodiments 67 to 73, wherein the space where the chopped carbon fiber bundles fall toward the travel path is divided into a plurality of regions along the T direction by at least one partition.

[0180] [Embodiment 75] The manufacturing apparatus according to Embodiment 74, wherein the at least one partition is formed of metal and grounded.

[0181] [Embodiment 76] A manufacturing apparatus for a carbon fiber sheet molding compound, comprising: a shredder disposed above the travel path of a carrier film; and at least one partition formed of metal and grounded, wherein the space where the chopped carbon fiber bundles fall toward the travel path is divided into a plurality of regions along the T direction by the at least one partition, and the chopped carbon fiber bundles are generated by cutting a continuous carbon fiber bundle using the shredder.

[0182] [Embodiment 77] The manufacturing apparatus according to Embodiment 76, further comprising a dispersing roll that is rotationally driven to disperse the chopped carbon fiber bundles.

[0183] [Embodiment 78] The manufacturing apparatus according to Embodiment 77, wherein a main portion of the dispersing roll is disposed in a compartment, and the manufacturing apparatus is provided with a chute for guiding the chopped carbon fiber bundles to an opening provided in the ceiling of the compartment.

[0184] [Embodiment 79] The manufacturing apparatus according to Embodiment 78, wherein a suction port connected to a dust collector is provided on one or both of the wall surface of the compartment and inside the compartment.

[0185] [Embodiment 80] The manufacturing apparatus according to any one of Embodiments 76 to 79, further comprising: an unbundler for unbundling the continuous carbon fiber bundle before cutting it using the shredder.

[0186] [Embodiment 81] The manufacturing apparatus according to Embodiment 80, wherein the unbundler includes a unit for piercing the continuous carbon fiber bundle with protrusions.

[0187] [Embodiment 82] The manufacturing apparatus according to Embodiment 81, wherein the unbundler includes a roll with protrusions.

[0188] [Embodiment 83] The manufacturing apparatus according to any one of Embodiments 80 to 82, wherein the unbundler includes a unit for bending the continuous carbon fiber bundle.

[0189] [Embodiment 84] The manufacturing apparatus according to Embodiment 83, wherein the unbundler includes a gear pair, and the gear pair is composed of two gears that mesh with each other and can be spur gears respectively.

[0190] [Embodiment 85] The manufacturing apparatus according to any one of Embodiments 45 to 84, wherein the carbon fiber sheet molding compound is obtained by impregnating a random mat formed of chopped carbon fiber bundles with a paste formed of a thermosetting resin composition.

[0191] [Embodiment 86] The manufacturing method according to any one of Embodiments 1 to 44, further comprising: before forming the random mat on the carrier film, applying a part of the paste on one surface of the carrier film; overlapping another carrier film having another part of the paste applied on one surface with the carrier film across the random mat to form a laminate; and compressing the laminate for the impregnation.

[0192] [Embodiment 87] A method for manufacturing a carbon fiber sheet molding compound, which uses the manufacturing apparatus according to any one of Embodiments 45 to 85.

[0193] 3. Experimental Results

[0194] The results of the experiments conducted by the present inventors are described below.

[0195] Using a CF-SMC manufacturing apparatus having a disperser disposed above the traveling path of the carrier film, a chopper disposed above the disperser, a plurality of guide tubes for passing a continuous carbon fiber bundle sent to the chopper therethrough, and a gear pair disposed on the upstream side of each guide tube, a random mat composed of chopped carbon fiber bundles was stacked on a carrier film not coated with a resin paste.

[0196] The following describes the steps in more detail.

[0197] Forty packages each having a continuous carbon fiber bundle with a filament number of 15K wound around a bobbin were prepared. The continuous carbon fiber bundles pulled out from each package were sent to the chopper through one guide tube after being passed between two spur gears constituting the gear pair.

[0198] Both of the spur gears included in each gear pair are made of SUS304, the tooth width (the length of the teeth in the axial direction of the gear) is 20 mm, the tooth height is 3.4 mm, the diameter of the addendum circle is 48 mm, and the length obtained by dividing the circumferential length of the addendum circle by the number of teeth is 5.0 mm. A mechanism for actively rotating the spur gear is not provided.

[0199] In each gear pair, two spur gears are meshed in such a way that the center distance between the shafts is 46 mm. The continuous carbon fiber bundle nipped between the two spur gears is stretched by the shredder, causing the two spur gears to rotate passively.

[0200] The guide tube is a polyethylene tube with an outer diameter of 20 mm and an inner diameter of 14 mm, and its length ranges from 3 m to 6 m. Therefore, the moving distance of any continuous carbon fiber bundle from being processed by the gear pair until being cut by the shredder exceeds 3 m.

[0201] In the disperser, two pin rollers are arranged, each having a rotating shaft parallel to the T direction. The two pin rollers have the same structure. The diameter of the cylinder is 120 mm, and the diameters and lengths of the pins arranged on the circumferential surface of the cylinder are 3 mm and 20 mm, respectively. The arrangement of the pins on the circumferential surface of the cylinder is periodic, and the pin density is 0.42 pins per 1 cm 2 0.42 pins. The center distance between the rotating shafts of the two pin rollers is 150 mm.

[0202] Both of the two pin rollers of the disperser rotate in such a way that the pins move downward from top to bottom on the side facing the other pin roller. The rotational speeds of the two pin rollers are the same.

[0203] The continuous carbon fiber bundle is cut by the shredder into short carbon fiber bundles with a cut fiber length of approximately 1 inch (25.4 mm). The short carbon fiber bundles are dispersed while passing through the disperser and then fall onto a carrier film moving at a linear speed of 5 m / minute. The falling short carbon fiber bundles accumulate on the carrier film to form a random mat.

[0204] Select an area of approximately 21 cm × 30 cm that accumulates near the center line of the carrier film from this random mat, and measure the weight of all the short carbon fiber bundles (more than 300 pieces) contained in this area. The weight average filament number calculated based on this weight measurement is used as the average filament number of the short carbon fiber bundles in the random mat.

[0205] The average filament numbers of the short carbon fiber bundles in the random mats obtained by rotating the pin rollers of the disperser at rotational speeds of 800 rpm, 1000 rpm, 1250 rpm, and 1500 rpm are shown in Table 1 below. Table 1 also shows the average filament numbers of the short carbon fiber bundles in the random mats formed in the same way except that the continuous carbon fiber bundle is not processed using the gear pair.

[0206] [Table 1]

[0207]

[0208] As described above, the present invention has been described according to specific embodiments, but each embodiment is presented as an example and does not limit the scope of the present invention. Each embodiment described in this specification can be variously modified within the scope of achieving the effects of the invention and can be combined with the features described in other embodiments within the implementable scope.

[0209] Industrial Applicability

[0210] The carbon fiber sheet molding compound manufactured by the manufacturing method or manufacturing apparatus of the usage embodiment can be suitably used for manufacturing CFRP components used in various transportation equipment or industrial equipment. Examples of the transportation equipment mentioned here include, but are not limited to, automobiles, ships, railway vehicles, manned aircraft, and unmanned aircraft.

[0211] Explanation of Reference Numerals

[0212] 1 Chopper

[0213] 2a First coater

[0214] 2b Second coater

[0215] 3 Impregnator

[0216] 10 Continuous carbon fiber bundle

[0217] 20 Chopped carbon fiber bundle

[0218] 30 Random mat

[0219] 41, 42 Paste

[0220] 51 First carrier film

[0221] 52 Second carrier film

[0222] 60 Laminate

[0223] BL Unbundler

[0224] GT Guide tube

[0225] GR Guide roll.

Claims

1. A manufacturing method of a carbon fiber sheet molding compound, comprising: feeding a continuous carbon fiber bundle pulled out from a package body through a guiding tube and sending it to a chopper; performing a defibrillation treatment on the continuous carbon fiber bundle before passing through the guiding tube; causing the short carbon fiber bundles generated by cutting the continuous carbon fiber bundle by using the chopper to fall onto a traveling carrier film to form a random mat; and impregnating the random mat with a paste formed of a thermosetting resin composition.

2. The manufacturing method according to claim 1, wherein, the defibrillation treatment includes piercing the continuous carbon fiber bundle with protrusions.

3. The manufacturing method according to claim 2, wherein, a roller with protrusions is used in the defibrillation treatment.

4. The manufacturing method according to any one of claims 1 to 3, wherein, the defibrillation treatment includes bending the continuous carbon fiber bundle.

5. The manufacturing method according to claim 4, wherein, a gear pair is used in the defibrillation treatment, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

6. The manufacturing method according to any one of claims 1 to 5, wherein, the short carbon fiber bundles are dispersed by a dispersing roller driven to rotate and then fall onto the carrier film.

7. The manufacturing method according to claim 6, which further includes: providing a compartment and disposing a main part of the dispersing roller therein; and using a chute to guide the short carbon fiber bundles to an opening provided in the ceiling of the compartment.

8. The manufacturing method according to claim 6 or 7, which further includes: while dispersing the short carbon fiber bundles by using the dispersing roller, removing the fiber dust generated thereby by a dust collector.

9. The manufacturing method according to claim 7, which further includes: while dispersing the short carbon fiber bundles by using the dispersing roller, removing the fiber dust generated thereby by a dust collector; a suction port connected to the dust collector is provided on either one or both of the wall surface of the compartment and inside the compartment.

10. The manufacturing method according to any one of claims 1 to 9, which further includes: dividing the space where the short carbon fiber bundles fall toward the carrier film into a plurality of regions along the T direction by at least one partition.

11. The manufacturing method according to claim 10, wherein, the at least one partition is formed of metal and grounded.

12. The manufacturing method according to any one of claims 1 to 11, wherein, the length of the guiding tube is 3 m or more, and may be 5 m or more or 7 m or more.

13. A manufacturing method of a carbon fiber sheet molding compound, which includes: sending a continuous carbon fiber bundle pulled out from a package body to a chopper; performing a defibrillation treatment on the continuous carbon fiber bundle before cutting it by using the chopper; causing the short carbon fiber bundles generated by cutting the continuous carbon fiber bundle by using the chopper to fall onto a traveling carrier film to form a random mat; and impregnating the random mat with a paste formed of a thermosetting resin composition, The moving distance of the continuous carbon fiber bundle from the start of the unbundling treatment to being cut by the chopper exceeds 3 m, exceeds 5 m, or exceeds 7 m.

14. The manufacturing method according to claim 13, wherein, the unbundling treatment includes piercing the continuous carbon fiber bundle with a protrusion.

15. The manufacturing method according to claim 14, wherein, a roller with protrusions is used in the unbundling treatment.

16. The manufacturing method according to any one of claims 13 to 15, wherein, the unbundling treatment includes bending the continuous carbon fiber bundle.

17. The manufacturing method according to claim 16, wherein, a gear pair is used in the unbundling treatment, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

18. The manufacturing method according to any one of claims 13 to 17, wherein, the chopped carbon fiber bundle is dispersed by a rotatably driven dispersion roller and then falls onto the carrier film.

19. The manufacturing method according to claim 18, which further includes: providing a compartment and disposing a main portion of the dispersion roller therein; and using a chute to guide the chopped carbon fiber bundle to an opening provided in the ceiling of the compartment.

20. The manufacturing method according to claim 18 or 19, which further includes: while dispersing the chopped carbon fiber bundle by the dispersion roller, removing fiber dust generated thereby using a dust collector.

21. The manufacturing method according to claim 19, which further includes: while dispersing the chopped carbon fiber bundle by the dispersion roller, removing fiber dust generated thereby using a dust collector; a suction port connected to the dust collector is provided on either one or both of the wall surface of the compartment and inside the compartment.

22. The manufacturing method according to any one of claims 13 to 21, which further includes: dividing the space where the chopped carbon fiber bundle falls toward the carrier film into a plurality of regions along the T direction by at least one partition.

23. The manufacturing method according to claim 22, wherein, the at least one partition is formed of metal and grounded.

24. The manufacturing method according to any one of claims 13 to 23, wherein, the continuous carbon fiber bundle passes through a guiding tube and is sent to the chopper, and the unbundling treatment is performed on the continuous carbon fiber bundle before passing through the guiding tube.

25. A manufacturing method of a carbon fiber sheet molding compound, including: forming a random mat by dropping a chopped carbon fiber bundle generated by cutting a continuous carbon fiber bundle using a chopper onto a moving carrier film; impregnating the random mat with a paste formed of a thermosetting resin composition; performing an unbundling treatment on the continuous carbon fiber bundle before cutting with the chopper; and dispersing the chopped carbon fiber bundle by a rotatably driven dispersion roller before dropping onto the carrier film.

26. The manufacturing method according to claim 25, which further includes: providing a compartment and disposing a main portion of the dispersion roller therein; and using a chute to guide the chopped carbon fiber bundle to an opening provided in the ceiling of the compartment.

27. The manufacturing method according to claim 25 or 26, further comprising: While dispersing the chopped carbon fiber bundles using the dispersion roll, removing the fiber dust generated therewith using a dust collector.

28. The manufacturing method according to claim 26, further comprising: While dispersing the chopped carbon fiber bundles using the dispersion roll, removing the fiber dust generated therewith using a dust collector; The suction port connected to the dust collector is provided on either one or both of the wall surface of the compartment and inside the compartment.

29. The manufacturing method according to any one of claims 25 to 28, wherein, The unbundling process includes piercing the continuous carbon fiber bundle with protrusions.

30. The manufacturing method according to claim 29, wherein, A roll with protrusions is used in the unbundling process.

31. The manufacturing method according to any one of claims 25 to 30, wherein, The unbundling process includes bending the continuous carbon fiber bundle.

32. The manufacturing method according to claim 31, wherein, A gear pair is used in the unbundling process, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

33. The manufacturing method according to any one of claims 25 to 32, further comprising: Dividing the space where the chopped carbon fiber bundles fall toward the carrier film into multiple regions along the T direction by at least one partition.

34. The manufacturing method according to claim 33, wherein, The at least one partition is formed of metal and grounded.

35. A manufacturing method of a carbon fiber sheet molding compound, comprising: Causing the chopped carbon fiber bundles generated by cutting a continuous carbon fiber bundle with a chopper to fall onto a traveling carrier film to form a random mat; Impregnating the random mat with a paste formed of a thermosetting resin composition; and Dividing the space where the chopped carbon fiber bundles fall toward the carrier film into multiple regions along the T direction by at least one partition, The at least one partition is formed of metal and grounded.

36. The manufacturing method according to claim 35, wherein, After dispersing the chopped carbon fiber bundles using a rotationally driven dispersion roll, causing them to fall onto the carrier film.

37. The manufacturing method according to claim 36, further comprising: Providing a compartment and disposing a main part of the dispersion roll and the at least one partition therein; and Using a chute to guide the chopped carbon fiber bundles to an opening provided in the ceiling of the compartment.

38. The manufacturing method according to claim 36 or 37, further comprising: While dispersing the chopped carbon fiber bundles using the dispersion roll, removing the fiber dust generated therewith using a dust collector.

39. The manufacturing method according to claim 37, further comprising: While dispersing the chopped carbon fiber bundles using the dispersion roll, removing the fiber dust generated therewith using a dust collector; The suction port connected to the dust collector is provided on either one or both of the wall surface of the compartment and inside the compartment.

40. The manufacturing method according to any one of claims 35 to 39, further Comprising: Before cutting with the shredder, perform a debundling process on the continuous carbon fiber bundle.

41. The manufacturing method according to claim 40, wherein, The debundling process includes piercing the continuous carbon fiber bundle with protrusions.

42. The manufacturing method according to claim 41, wherein, A roller with protrusions is used in the debundling process.

43. The manufacturing method according to any one of claims 40 to 42, wherein, The debundling process includes bending the continuous carbon fiber bundle.

44. The manufacturing method according to claim 43, wherein, A gear pair is used in the debundling process, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

45. A manufacturing apparatus for carbon fiber sheet molding compound, comprising: A shredder disposed above the traveling path of the carrier film; A guiding tube for allowing the continuous carbon fiber bundle pulled out from the package and sent to the shredder to pass through; and A debundler disposed at a position upstream of the guiding tube to untangle the continuous carbon fiber bundle.

46. The manufacturing apparatus according to claim 45, wherein, The debundler includes a unit for piercing the continuous carbon fiber bundle with protrusions.

47. The manufacturing apparatus according to claim 46, wherein, The debundler includes a roller with protrusions.

48. The manufacturing apparatus according to any one of claims 45 to 47, wherein, The debundler includes a unit for bending the continuous carbon fiber bundle.

49. The manufacturing apparatus according to claim 48, wherein, The debundler includes a gear pair, and the gear pair is composed of two gears that can be spur gears and mesh with each other.

50. The manufacturing apparatus according to any one of claims 45 to 49, further comprising a rotatably driven dispersion roller for dispersing the short carbon fiber bundles generated by cutting the continuous carbon fiber bundle with the shredder.

51. The manufacturing apparatus according to claim 50, wherein, The main part of the dispersion roller is disposed in a compartment, and the manufacturing apparatus is provided with a chute for guiding the short carbon fiber bundles to an opening provided on the ceiling of the compartment.

52. The manufacturing apparatus according to claim 51, wherein, A suction port connected to a dust collector is provided on one or both of the wall surface of the compartment and inside the compartment.

53. The manufacturing apparatus according to any one of claims 45 to 52, wherein, The space where the short carbon fiber bundles fall toward the traveling path is divided into a plurality of regions along the T direction by at least one partition, and the short carbon fiber bundles are generated by cutting the continuous carbon fiber bundle with the shredder.

54. The manufacturing apparatus according to claim 53, wherein, The at least one partition is formed of metal and grounded.

55. The manufacturing apparatus according to any one of claims 45 to 54, wherein, The length of the guiding tube is 3 m or more, and may be 5 m or more or 7 m or more.

56. A manufacturing apparatus for carbon fiber sheet molding compound, comprising: A shredder disposed above the traveling path of the carrier film; and A unbundler for unbundling a continuous carbon fiber bundle pulled out from a package and sent to the shredder. The distance from the unbundler to the shredder along the traveling path of the continuous carbon fiber bundle exceeds 3 m, exceeds 5 m, or exceeds 7 m.

57. The manufacturing apparatus according to claim 56, wherein, the unbundler includes a unit for piercing a protrusion into the continuous carbon fiber bundle.

58. The manufacturing apparatus according to claim 57, wherein, the unbundler includes a roller with protrusions.

59. The manufacturing apparatus according to any one of claims 56 to 58, wherein, the unbundler includes a unit for bending the continuous carbon fiber bundle.

60. The manufacturing apparatus according to claim 59, wherein, the unbundler includes a gear pair composed of two gears that can be spur gears and mesh with each other.

61. The manufacturing apparatus according to any one of claims 56 to 60, further comprising a rotatably driven dispersing roller for dispersing the short carbon fiber bundles generated by cutting the continuous carbon fiber bundle with the shredder.

62. The manufacturing apparatus according to claim 61, wherein, a main part of the dispersing roller is disposed in a compartment, and the manufacturing apparatus is provided with a chute for guiding the short carbon fiber bundles to an opening provided in the ceiling of the compartment.

63. The manufacturing apparatus according to claim 62, wherein, a suction port connected to a dust collector is provided on either one or both of the wall surface of the compartment and inside the compartment.

64. The manufacturing apparatus according to any one of claims 56 to 63, wherein, the space where the short carbon fiber bundles fall along the traveling path is divided into a plurality of regions in the T direction by at least one partition, and the short carbon fiber bundles are generated by cutting the continuous carbon fiber bundle with the shredder.

65. The manufacturing apparatus according to claim 64, wherein, the at least one partition is formed of metal and grounded.

66. The manufacturing apparatus according to any one of claims 56 to 65, further comprising a guiding tube for allowing the continuous carbon fiber bundle sent to the shredder to pass through, and the unbundler is disposed at a position more upstream than the guiding tube.

67. A manufacturing apparatus for a carbon fiber sheet molding compound, comprising: a shredder disposed above the traveling path of a carrier film; an unbundler for unbundling a continuous carbon fiber bundle sent to the shredder; and a rotatably driven dispersing roller for dispersing the short carbon fiber bundles generated by cutting the continuous carbon fiber bundle with the shredder.

68. The manufacturing apparatus according to claim 67, wherein, the dispersing roller is disposed in a compartment, and the manufacturing apparatus is provided with a chute for guiding the short carbon fiber bundles to an opening provided in the ceiling of the compartment.

69. The manufacturing apparatus according to claim 68, wherein, a suction port connected to a dust collector is provided on either one or both of the wall surface of the compartment and inside the compartment.

70. The manufacturing apparatus according to any one of claims 67 to 69, wherein, The unbundler includes a unit that pierces the protrusions into the continuous carbon fiber bundle.

71. The manufacturing apparatus according to claim 70, wherein, the unbundler includes a roller with protrusions.

72. The manufacturing apparatus according to any one of claims 67 to 71, wherein, the unbundling process includes a unit that bends the continuous carbon fiber bundle.

73. The manufacturing apparatus according to claim 72, wherein, the unbundler includes a gear pair composed of two gears that can be spur gears and mesh with each other.

74. The manufacturing apparatus according to any one of claims 67 to 73, wherein, the space where the chopped carbon fiber bundle falls toward the traveling path is divided into a plurality of regions along the T direction by at least one partition.

75. The manufacturing apparatus according to claim 74, wherein, the at least one partition is formed of metal and grounded.

76. A manufacturing apparatus for a carbon fiber sheet molding compound, comprising: a shredder disposed above the traveling path of a carrier film, and at least one partition formed of metal and grounded, the space where the chopped carbon fiber bundle falls toward the traveling path is divided into a plurality of regions along the T direction by the at least one partition, and the chopped carbon fiber bundle is generated by cutting a continuous carbon fiber bundle using the shredder.

77. The manufacturing apparatus according to claim 76, further comprising a dispersing roller that is rotationally driven to disperse the chopped carbon fiber bundle.

78. The manufacturing apparatus according to claim 77, wherein, a main portion of the dispersing roller is disposed in a compartment, and the manufacturing apparatus is provided with a chute for guiding the chopped carbon fiber bundle to an opening provided in the ceiling of the compartment.

79. The manufacturing apparatus according to claim 78, wherein, a suction port connected to a dust collector is provided on either or both of the wall surface of the compartment and inside the compartment.

80. The manufacturing apparatus according to any one of claims 76 to 79, further comprising an unbundler for unbundling the continuous carbon fiber bundle before cutting it using the shredder.

81. The manufacturing apparatus according to claim 80, wherein, the unbundler includes a unit that pierces the protrusions into the continuous carbon fiber bundle.

82. The manufacturing apparatus according to claim 81, wherein, the unbundler includes a roller with protrusions.

83. The manufacturing apparatus according to any one of claims 80 to 82, wherein, the unbundler includes a unit that bends the continuous carbon fiber bundle.

84. The manufacturing apparatus according to claim 83, wherein, the unbundler includes a gear pair composed of two gears that can be spur gears and mesh with each other.

85. The manufacturing apparatus according to any one of claims 45 to 84, wherein, the carbon fiber sheet molding compound is obtained by impregnating a random mat formed of chopped carbon fiber bundles with a paste formed of a thermosetting resin composition.

86. The manufacturing method according to any one of claims 1 to 44, further comprising: Before forming the nonwoven felt on the carrier film, a part of the paste is coated on one surface of the carrier film; Another carrier film coated with another part of the paste on one surface is overlapped with the carrier film across the nonwoven felt to form a laminate; and The laminate is compressed for the impregnation.

87. A method for manufacturing a carbon fiber sheet molding compound, which uses the manufacturing apparatus according to any one of claims 45 to 85.

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