Method for producing sheet molding compound and fiber mat deposition device

Abstract

According to one aspect of the present invention, there is provided CF-SMC production technology such that it is possible to inhibit contamination of a product with lint originating from fiber dust, even while using a disperser roll.　An SMC production method according to one aspect of the present invention includes: (i) drawing out a carrier film from a roll and causing the same to travel on a conveyance path such that the surface thereof is horizontal; (ii) cutting continuous carbon fiber bundles with a chopper disposed above the conveyance path and converting the continuous carbon fiber bundles to short carbon fiber bundles; (iii) causing the short carbon fiber bundles to fall onto the carrier film traveling on the conveyance path while dispersing the short carbon fiber bundles using a disperser roll disposed below the chopper, and causing the deposition of a carbon fiber mat on the carrier film; (iv) impregnating the carbon fiber mat with a thermosetting resin composition and converting the carbon fiber mat to a resin-impregnated carbon fiber mat; and (v) simultaneously with causing the deposition of the carbon fiber mat, using a dust collector to remove fiber dust generated from the short carbon fiber bundles via contact with the disperser roll.

Description

[Technical Field]

[0001] The present invention relates primarily to a method for producing sheet molding compound (SMC), particularly to a method for producing SMC (CF-SMC) using carbon fiber (CF) as a reinforcing material, and to a fiber mat deposition device used in the production of CF-SMC. This application claims priority based on Patent Application No. 2021-116973 filed with the Japan Patent Office on July 15, 2021, and Patent Application No. 2022-078871 filed with the Japan Patent Office on May 12, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] Carbon fiber reinforced plastics (CFRP) are lightweight composite materials with excellent mechanical properties that are suitable for parts of manned aircraft, unmanned aerial vehicles, automobiles, ships, railway vehicles, and other transportation equipment, and their importance has been increasing in recent years. When manufacturing CFRP products by compression molding, the intermediate material preferably used is carbon fiber prepreg, which is made by impregnating a reinforcing material made of carbon fiber with an uncured thermosetting resin composition.

[0003] CF-SMC is a type of carbon fiber prepreg, and its manufacturing process involves chopping a continuous carbon fiber bundle into short carbon fiber bundles with a chopper, dropping the bundles onto a moving carrier film to form a carbon fiber mat. CF-SMC is then produced by impregnating the carbon fiber mat with a thermosetting resin composition. A fiber mat manufacturing device has been proposed in which a pin roll or cage roll is placed between the chopper and the carrier film conveying path in order to uniformly disperse the short fiber bundles falling from the chopper onto the carrier film or to strike them to break them into smaller bundles (Patent Document 1, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 142851 [Patent Document 2] International Publication No. 2021 / 010084 Summary of the Invention [Problem to be solved by the invention]

[0005] When short carbon fiber bundles come into contact with a dispersion roll such as a pin roll or cage roll, the impact generates fiber dust. The fiber dust is suspended by the airflow generated by the rotation of the dispersion roll and can then settle on the surfaces of components in SMC manufacturing equipment, forming cotton dust. When large cotton dust particles fall and become mixed into the carbon fiber mat, impregnation defects occur in those areas. Because the CF-SMC does not flow sufficiently in impregnated areas, CF-SMC with impregnated areas may damage the mold when used in compression molding. The fibrous dust may also contaminate the mechanical components of the SMC manufacturing equipment and deteriorate the working environment in the room where the SMC manufacturing equipment is installed.Since the fibrous dust generated from carbon fibers is conductive, it may also interfere with the operation of electrical and electronic equipment.

[0006] The object of the present invention is to provide a manufacturing technique for CF-SMC that can suppress the inclusion of cotton dust derived from the fiber dust in the product even when a dispersion roll is used. Another object of the present invention is to provide a fiber mat deposition device that can suppress the adverse effects of the fiber dust on the mechanical elements of the SMC manufacturing equipment and the working environment within the room where the SMC manufacturing equipment is installed. In this specification, problems that can be solved by each embodiment of the present invention may be explicitly or implicitly disclosed. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a method for producing a sheet molding compound, comprising: (i) unrolling a carrier film from a roll and running the carrier film along a conveying path so that its surface is horizontal; (ii) cutting the continuous carbon fiber bundles with a chopper arranged above the conveying path to form short carbon fiber bundles; (iii) dispersing the short carbon fiber bundles using a dispersing roll arranged below the chopper while dropping them onto the carrier film running along the conveying path to deposit a carbon fiber mat on the carrier film; (iv) impregnating the carbon fiber mat with a thermosetting resin composition to form a resin-impregnated carbon fiber mat; and (v) simultaneously with depositing the carbon fiber mat, removing fiber dust generated from the short carbon fiber bundles due to contact with the dispersing roll using a dust collector.

[0008] According to another aspect of the present invention, there is provided a method for producing a sheet molding compound using a fiber mat deposition device having a chopping section and a dispersion section located below the chopping section, the method including: (i) unrolling a carrier film from a roll and running the film along a conveying path so that its surface is horizontal; (ii) cutting continuous carbon fiber bundles into short carbon fiber bundles in the chopping section of the fiber mat deposition device located above the conveying path; (iii) dispersing the short carbon fiber bundles in the dispersion section of the fiber mat deposition device using a dispersion roll having a rotation axis parallel to the T direction while dropping the short carbon fiber bundles onto the carrier film running along the conveying path, thereby depositing a carbon fiber mat on the carrier film; (iv) impregnating the carbon fiber mat with a thermosetting resin composition to form a resin-impregnated carbon fiber mat; and (v) simultaneously depositing the carbon fiber mat, removing fiber dust generated from the short carbon fiber bundles due to contact with the dispersion roll using one or more dust collectors.

[0009] According to yet another aspect of the present invention, there is provided a fiber mat deposition device that is disposed above a conveying path and used to deposit a carbon fiber mat on a carrier film that runs on the conveying path with its surface horizontal, the fiber mat deposition device comprising: a chopping section that cuts continuous carbon fiber bundles into short carbon fiber bundles; and a dispersion section that is disposed below the chopping section and that drops the short carbon fiber bundles onto the carrier film while dispersing them using a dispersion roll having a rotation axis parallel to the T direction, wherein the dispersion section is disposed inside an enclosure and at least one end of the shaft of the dispersion roll protrudes outside the enclosure through an opening provided in the enclosure.

[0010] According to yet another aspect of the present invention, there is provided a fiber mat deposition device that is disposed above a conveying path and is used to deposit carbon fiber mats on a carrier film that runs on the conveying path with its surface horizontal, the fiber mat deposition device comprising: a chopping section that cuts continuous carbon fiber bundles into short carbon fiber bundles; and a dispersion section that is disposed below the chopping section and that drops the short carbon fiber bundles onto the carrier film while dispersing them using a dispersion roll having a rotation axis parallel to the T direction, wherein the dispersion section is disposed inside an enclosure, both ends of the shaft of the dispersion roll each protrude outside the enclosure through an opening provided in the enclosure, and both of a pair of bearings that support the shaft are disposed outside the enclosure.

[0011] According to yet another aspect of the present invention, there is provided a fiber mat deposition device comprising: a chopping section for cutting continuous carbon fiber bundles into short carbon fiber bundles; and a dispersion section disposed below the chopping section for dispersing the short carbon fiber bundles using a dispersion roll and causing them to fall onto a carrier film, wherein the dispersion section is disposed inside an enclosure formed of a metal plate and grounded.

[0012] According to yet another aspect of the present invention, there is provided a sheet molding compound manufacturing apparatus comprising a fiber mat depositing device, two coaters, a laminator, an impregnator, and one or more dust collectors. [Effects of the Invention]

[0013] According to one aspect of the present invention, there is provided a CF-SMC manufacturing technology that can suppress the inclusion of cotton dust, which is derived from fiber dust generated from short carbon fiber bundles due to contact with a dispersion roll, in the product. According to another aspect of the present invention, a fiber mat deposition device is provided that can suppress the adverse effects of fiber dust generated from short carbon fiber bundles due to contact with a dispersion roll on the mechanical elements of an SMC manufacturing apparatus and the working environment within the room where the SMC manufacturing apparatus is installed. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram of an SMC manufacturing device. [Figure 2] FIG. 2 is a schematic diagram of a fiber mat deposition apparatus. [Figure 3] FIG. 3 is a schematic diagram of a fiber mat deposition apparatus. [Figure 4] FIG. 4 is a schematic diagram of a pin roll. [Figure 5] FIG. 5 is a schematic diagram showing the positional relationship between two pin rolls in the disperser. [Figure 6] FIG. 6 is a schematic diagram of a cage roll. [Figure 7] FIG. 7 is a schematic diagram of a fiber mat deposition apparatus. [Figure 8] FIG. 8 is a schematic diagram of a suction nozzle. [Figure 9] FIG. 9 is a schematic diagram of a suction nozzle. [Figure 10] FIG. 10 is a schematic diagram of a suction nozzle. [Figure 11] FIG. 11 is a schematic diagram of a fiber mat deposition apparatus. [Figure 12] FIG. 12 is a schematic diagram of a fiber mat deposition apparatus. [Figure 13] FIG. 13 is a schematic diagram of a fiber mat deposition apparatus. [Figure 14] FIG. 14 is a schematic diagram showing a portion of a fiber mat deposition apparatus. [Figure 15] FIG. 15 is a schematic diagram showing a portion of a fiber mat deposition apparatus. [Figure 16] FIG. 16 is a schematic diagram of a fiber mat deposition apparatus. [Figure 17] FIG. 17 is a schematic diagram of a fiber mat deposition apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0015] The "T direction" as used herein means a horizontal direction perpendicular to the M direction. The M direction is the running direction of the carrier film during the production of CF-SMC. For example, in Figures 1, 2, 11 to 13, 16, and 17, the T direction is perpendicular to the paper surface. The term "metal" as used in this specification includes not only simple metals but also alloys.

[0016] 1.SMC manufacturing equipment FIG. 1 shows an example of an SMC manufacturing apparatus that can be preferably used in the CF-SMC manufacturing method according to the embodiment. Referring to FIG. 1, an SMC manufacturing apparatus 100 includes a first coater 110, a second coater 120, a fiber mat depositing device 130, and an impregnating device 140. The first coater 110 is used to apply the first resin paste 51 to the first carrier film 41 to form the first resin paste layer 51L. The second coater 120 is used to apply the second resin paste 52 to the second carrier film 42 to form the second resin paste layer 52L.

[0017] As shown in FIGS. 2 and 3, the fiber mat depositing device 130 is disposed above the transport path of the first carrier film 41 and includes a chopping section 150, a dispersing section 160, an enclosure 170, and a suction nozzle 180. The surface of the transported first carrier film 41 is held horizontally below the fiber mat depositing device 130. This is to prevent the fallen short carbon fiber bundles 20 and the deposited fiber mats 30 from moving on the surface of the first carrier film 41 due to gravity.

[0018] The chopping section 150 uses a chopper of the type conventionally used in SMC manufacturing equipment, that is, a chopper equipped with a cutter roll 151, a receiving roll (rubber roll) 152, and a guide roll 153, each of which has a rotation axis parallel to the T direction. During the production of CF-SMC, the continuous carbon fiber bundle 10 supplied to the fiber mat deposition device 130 is cut in the chopping section 150. The chopping section 150 may cut the continuous carbon fiber bundles 10 so that the angle between the longitudinal direction of the continuous carbon fiber bundles 10 and the cut surface is 80° or less, 45° or less, or 30° or less.

[0019] In the fiber mat deposition apparatus 130 , the chopping section 150 is located inside an enclosure 170 . The electric motor and power transmission system (not shown) for driving the rotation of the cutter roll 151 and the backing roll 152 are preferably located outside the enclosure 170 to avoid contamination by fiber dust. When the cutter roll 151 and the backing roll 152 are connected to a power transmission system outside the enclosure 170, openings are provided in the enclosure 170 to allow at least one end of the shafts of these rolls to protrude outside the enclosure 170. Preferably, the size of the openings is minimized to prevent fiber dust from leaking out of the enclosure 170 through the openings. Preventing fiber dust from leaking outside the enclosure 170 is beneficial not only in preventing contamination of mechanical components located outside the enclosure 170, but also in improving the working environment within the room where the SMC manufacturing apparatus 100 is installed.

[0020] In the dispersion section 160, a pair of pin rolls arranged side by side, that is, a first pin roll 161 and a second pin roll 162, are used as dispersion rolls. The dispersion section 160 is arranged below the chopping section 150, and during the production of CF-SMC, the short carbon fiber bundles 20 dropping from the chopping section 150 are dispersed in the dispersion section 160. Both the first pin roll 161 and the second pin roll 162 have rotation axes parallel to the T direction, and are both driven to rotate by a drive mechanism (not shown). The rotational speeds of the first pin roll 161 and the second pin roll 162 may be independently controllable.

[0021] 4, the first pin roll 161 has a cylinder 161a, a plurality of pins 161b arranged on the circumferential surface of the cylinder 161a, and a shaft 161c that passes through the center of the cylinder 161a in the direction of the rotation axis. It is preferable that all of the plurality of pins 161b have the same shape and dimensions. Both the cylinder 161a and the pin 161b are rigid bodies, and are made of, for example, metal. The diameter of the cylinder 161a is not limited to, but may be, for example, 60 mm to 150 mm. The larger the diameter of the cylinder 161a, the higher the peripheral speed at which the pins 161b move when the first pin roll 161 is rotated, and the higher the ability to disperse the short carbon fiber bundles.

[0022] The pin 161b extends perpendicular to the rotation axis of the first pin roll 161 and has, for example, but not limited to, a cylindrical shape. The boundary between the end face and the peripheral surface of the pin 161b may be chamfered. The diameter of the pin 161b is not limited to, but may be, for example, 1 mm to 5 mm. The length of the pin 161b, that is, the distance from the tip to the base of the pin, is not limited to, but can be, for example, 10 mm to 50 mm.

[0023] The pins 161b are preferably arranged periodically on the circumferential surface of the cylinder 161a in both the axial and circumferential directions. The arrangement period of the pins 161b on the circumferential surface of the cylinder 161a can be, for example, 5 mm or more and less than 20 mm, 20 mm or more and less than 40 mm, or 40 mm or more and less than 60 mm in the axial direction. In the example of Figure 4, the arrangement of pins 161b on the circumferential surface of cylinder 161a has a circumferential period of 90°, but periods other than 90°, such as 5°, 10°, 15°, 20°, 24°, 30°, 45°, 60°, 72°, 120°, and 180°, can also be used.

[0024] In this specification, the maximum radius of a pin roll is defined as the distance from its rotation axis to the tip of the longest pin. In the first pin roll 161, the radius of the cylinder 161a is preferably at least half, and more preferably at least 75%, of the maximum radius of the first pin roll 161. This is because the higher the ratio of the cylinder radius to the maximum radius of the pin roll, the smaller the difference in peripheral speed between the tip and base of the pins when the pin roll is rotating.

[0025] Everything stated above regarding the first pin roll 161 also applies to the second pin roll 162. To reduce the design, manufacturing, and maintenance costs of the fiber mat deposition apparatus 130, it is preferable to match the design and specifications of the first pin roll 161 and the second pin roll 162 in as many areas as possible, including, but not limited to, axial length, maximum radius, cylinder diameter, pin shape, dimensions, number, and arrangement, and cylinder and pin materials.

[0026] As shown in FIG. 5 , the maximum radius r of the first pin roll 161 is set to 1 / 2, so that as many short carbon fiber bundles 20 as possible are struck by the pins of the first pin roll 161 and the second pin roll 162 when passing between these pin rolls. M1 and the maximum radius r of the second pin roll 162 M2 The sum of these is the distance between the rotation axes of these two pin rolls d 12 It is preferable that it is greater than . Maximum radius r of the first pin roll 161 M1 and the cylinder radius r of the second pin roll 162 C2 and the cylinder radius r of the first pin roll 161 C1 and the maximum radius r of the second pin roll 162 M2The sum of both is the distance between the rotation axes of the two pin rolls, d 12 Smaller than.

[0027] In one example, the maximum radius r of the first pin roll 161 in the fiber mat deposition device 130 M1 and the maximum radius r of the second pin roll 162 M2 The sum of these is the distance between the rotation axes of these two pin rolls d 12 may be equal to In another example, the maximum radius r of the first pin roll 161 in the fiber mat deposition device 130 M1 and the maximum radius r of the second pin roll 162 M2 The sum of these is the distance between the rotation axes of these two pin rolls d 12 The difference {d 12 -(r M1 +r M2 )} is preferably 10 mm or less, more preferably 5 mm or less.

[0028] In the fiber mat deposition apparatus 130 , the distribution section 160 is disposed inside an enclosure 170 . The electric motor and power transmission (not shown) for driving the rotation of the first pin roll 161 and the second pin roll 162 are preferably located outside the enclosure 170 to avoid contamination with fiber dust. When the first pin roll 161 and the second pin roll 162 are connected to a power transmission system outside the enclosure 170, openings are provided in the enclosure 170 to allow at least one end of each of the shafts 161c, 162c to protrude outside the enclosure 170. Preferably, the size of the openings is minimized to prevent fiber dust from leaking out of the enclosure 170 through the openings. Preventing fiber dust from leaking outside the enclosure 170 is beneficial not only in preventing contamination of mechanical elements located outside the enclosure 170, but also in improving the working environment within the room where the SMC manufacturing equipment is installed.

[0029] 14, two bearings B1 supporting shaft 161c of the first pin roll and two bearings B2 supporting shaft 162c of the second pin roll may be located outside enclosure 170 to avoid contamination by fiber dust. In this case, an opening OP required for this purpose is provided in enclosure 170. Preferably, the size of the opening is minimized to prevent fiber dust from leaking out of enclosure 170 through the opening.

[0030] 14, in order to more effectively prevent fiber dust from leaking out of the enclosure 170 through the openings OP, two collars C are provided on each of the first pin roll 161 and the second pin roll 162. Each opening OP is preferably circular, and each collar C is preferably disk-shaped. Each collar C is adjacent to an aperture OP inside the enclosure 170. On a plane perpendicular to the T direction, the orthogonal projection of an aperture OP falls within the outline of the orthogonal projection of the collar C adjacent to the aperture OP.

[0031] Referring to FIG. 15, the gap G1 between the collar C and the enclosure 170 can be, for example, 5 mm or less, 3 mm or less, or 1 mm or less, and the narrower the gap, the more preferable it is for preventing fiber dust from leaking out of the enclosure 170. 14 and 15, a cylindrical ring R integrated with a collar C may be inserted into an opening OP provided in the enclosure 170. A gap G2 between the cylindrical ring R and the opening OP may be, for example, 5 mm or less, 3 mm or less, or 1 mm or less. The narrower the gap, the more preferable it is for preventing fibrous dust from leaking out of the enclosure 170. The use of color C is preferred but not required.

[0032] The number of distribution rolls used in the distribution section is not limited to 2. In one example, the number of distribution rolls used in the distribution section may be 1, or may be 3 or more. In one example, in addition to or instead of a pin roll, a type of dispersion roll other than a pin roll may be used in the dispersion section.

[0033] Like the pins in a pin roll, the dispersing roll needs an element that moves in the circumferential direction when rotated and strikes the short carbon fiber bundles 20. To satisfy this requirement, the dispersing roll needs to have n-fold rotational symmetry about the rotation axis (where n is an integer of 1 or more, is finite, and is preferably 72 or less). n may be 45 or less, 36 or less, or 24 or less. For example, the first pin roll 161 shown in FIG. 4 has four-fold rotational symmetry about the rotation axis. 6 is an example of a dispersion roll other than a pin roll. The cage roll 164 has a structure in which multiple rods 164b are hung between a pair of disks 164a that share a common rotation axis, and a shaft 164c passes through the center of each disk 164a.

[0034] 6, six rods 164b are arranged at equal intervals in the circumferential direction on a cylindrical surface centered on the rotation axis, so that the cage roll 164 has six-fold rotational symmetry around the rotation axis. The material of the rods 164c is preferably metal, but is not limited to this. When the cage roll 164 is rotated, the rods 164c move in the circumferential direction and strike the short carbon fiber bundles 20. In a variant, the rods 164c of the cage roll 164 may be replaced by rods having a non-round cross section, such as square or flat bars, or may be replaced by taut wire.

[0035] In one example of a cage roll, a plurality of rods may be arranged at equal intervals in the circumferential direction on each of several concentric cylindrical surfaces centered on the rotation axis. The number of rods arranged on each cylindrical surface is not particularly limited, but may be, for example, 3 to 8. The cage roll according to one example may have a structure in which a plurality of structural units, each having a pair of disks sharing a rotation axis and a plurality of rods stretched between them, are arranged in the longitudinal direction of the shaft. In this case, one disk may be shared between adjacent structural units.

[0036] Referring again to Figures 2 and 3, the enclosure 170 consists of an upper part 171 that constitutes a chute that guides the short carbon fiber bundles 20 from the chopping section 150 to the dispersing section 160, and a lower part 172 that constitutes the housing of a fiber spraying booth that has the dispersing section 160 inside. The enclosure 170 is made of metal or resin plates and does not have ventilation. The enclosure 170 is usually made of multiple plates. It is not necessary for all parts of the enclosure 170 to be made of plates of the same material.

[0037] When fibrous dust adheres to the surface of the enclosure 170 due to static electricity, this can trigger the formation of cotton dust. To prevent this, it is preferable that the enclosure 170 is formed from a metal plate and further grounded, as shown in the example of FIG. 17. In the example of FIG. 17, a grounding cable extends from the lower part 172 of the enclosure 170 to the grounding point 174, but in one example, the grounding cable may extend from the upper part 171 of the enclosure 170. The grounding method is not limited to these examples. Suitable examples of the material for the metal plate include aluminum alloy and stainless steel, with aluminum alloy being more preferable due to its high conductivity. If the inner surface of the enclosure 170 is scratched, lint may form as fibrous dust gets caught in the scratch. Because aluminum alloy plates are easily scratched, they may be electroless nickel plated before use to increase their surface hardness.

[0038] The upper and lower parts 171 and 172 of the enclosure are connected without any gaps, and air does not flow from the inside to the outside of the enclosure 170 at the joint between the two. As a result, fiber dust generated from the short carbon fiber bundles that come into contact with the first pin roll 161 or the second pin roll 162 is carried by the air currents generated by these dispersion rolls, floats inside the enclosure 170, and rises, potentially reaching the height of the top of the enclosure 170. The configuration of the enclosure 170 is not limited to that shown in Figures 2 and 3. As in the example shown in Figure 7, the enclosure 170 may have the same horizontal cross-sectional shape from the top to the bottom. The SMC manufacturing apparatus 100 may have a frame for fixing a chopper, dispersion rolls, etc., and such a frame may form a part of the enclosure 170.

[0039] As shown in FIG. 2, enclosure 170 is continuous between a first height H1 (defined below) and a second height H2 (defined below). The first height H1 is the height of the rotation shafts of the cutter roll and the receiving roll of the chopper used in the chopping section 150, and if these heights are different, it refers to the height of the higher position. The second height H2 refers to the height of the rotation shaft of the dispersion roll used in the dispersion section 160, which has the rotation shaft at the lowest position. In a preferred embodiment, the top of the enclosure 170 may be located higher than the first height H1. In a preferred embodiment, the position of the lower end of the enclosure 170 may be lower than the second height H2, and may also be lower than the third height H3 defined below.

[0040] The third height H3 refers to the lowest point height of the dispersion roll with the lowest lowest point height among the dispersion rolls used in the dispersion section. The lowest point height refers to the height obtained by subtracting the maximum radius of the dispersion roll from the height of the dispersion roll's rotation axis. The maximum radius of the dispersion roll is defined as the radius of a cylinder that has the rotation axis of the dispersion roll as its central axis and circumscribes the dispersion roll. Therefore, in the case of a pin roll, the maximum radius is the distance from the rotation axis to the tip of the longest pin, and in the case of a cage roll, the maximum radius is the radius of a pair of disks provided for craning the rod or wire. It should be noted that in Figure 3, the first height H1, the second height H2, and the third height H3 are represented based on the surface of the first carrier film 41, but this is for convenience and the height reference does not necessarily have to be the surface of the first carrier film 41.

[0041] When "front and rear" are defined as the direction moving from rear to front as direction M, in the example shown in Figures 2 and 3, suction nozzles 180 each having suction port forming portions 180a are attached to the front and rear of the upper end of enclosure 170. The same is true for the example shown in Figure 7. The two suction nozzles 180 each have a suction port forming portion 180a that has a longitudinal direction, and are arranged with the longitudinal direction parallel to the direction T. The orientation of the suction port forming portion 180a is set so that it can suck in fibrous dust rising inside the enclosure 170. As shown in FIG. 8, the main body of the suction nozzle 180 is a cylinder with both ends closed, and the suction port forming portion 180a is provided on the side surface thereof. The suction nozzle 180 has a connection part for connecting to the hose 181 at one end in the longitudinal direction, but FIG. 8 is merely an example, and there is no limitation on the position and number of the connection part for connecting to the hose on the suction nozzle.

[0042] The suction port formed in the suction port forming portion 180a is preferably a slit type as in the example shown in FIG. 8, but is not limited thereto. For example, as shown in FIG. 9, the suction port forming portion 180a may have a plurality of suction ports lined up. The shape of the main body of the suction nozzle 180 is not limited either, and may be a shape other than a cylinder, as in the example shown in FIG.

[0043] 3 and 7, the suction nozzle 180 is connected to a dust collector 182 by a hose 181. The dust collector 182 is preferably a dust collector equipped with a separator that separates dust from air by using centrifugal force, i.e., a cyclone dust collector. The dust collector 182 is operated during the production of CF-SMC, and at least a portion of the fiber dust that floats and rises inside the enclosure 170 and reaches the height of its upper end is sucked and removed through the suction nozzle 180 before exiting the fiber mat deposition device 130. In order to remove as much fibrous dust as possible, the width W of the suction port forming portion 180a of the suction nozzle 180 is preferably 50% or more of the inner dimension of the enclosure 170 in the T direction, more preferably 75% or more, even more preferably 90% or more, and may be 100% or more.

[0044] In one example, the suction nozzle 180 may be located inside the enclosure 170 in addition to or instead of at the top of the enclosure 170 . A preferred example of the arrangement of the suction nozzle 180 is an arrangement in which the suction port forming section 180a faces the cutter roll 151 or the receiving roll 152 of the chopping section 150, as in the example of FIG. By arranging the suction nozzle 180 in this manner, the fibrous dust can be effectively removed with a small amount of suction airflow while the rising air current containing the fibrous dust passes through the narrow spaces between the enclosure 170 and the cutter roll 151 and between the enclosure 170 and the receiving roll 152. In one example, at least one suction nozzle 180 may be positioned inside the lower portion 172 of the enclosure 170 . Instead of placing a suction nozzle inside the enclosure 170, the enclosure 170 may be provided with an exhaust port which is connected to a dust collector by a hose.

[0045] The path of the airflow generated inside the enclosure 170 during the production of CF-SMC can vary depending on the design and operating conditions of the fiber mat deposition device 130. Therefore, it is possible to investigate locations where cotton dust is frequently generated when CF-SMC is produced without using a dust collector, and then position a suction nozzle on the path of the airflow toward those locations. To clarify this path, it is also possible to investigate how the amount of cotton dust generated at several locations changes depending on the position of the suction nozzle when CF-SMC is produced while operating a dust collector. In this way, the position of the suction nozzle can be optimized by trial and error.

[0046] In one example, to effectively prevent fiber dust from leaking out of the enclosure, the upper end of enclosure 170 may be closed with a ceiling panel 173, as shown in Fig. 13. In the example of Fig. 13, instead of arranging suction nozzle 180 inside enclosure 170, exhaust port 183 is provided in enclosure 170, and exhaust port 183 is connected to dust collector 182 by hose 181. The arrangement of exhaust port 183 can be optimized by trial and error, as in the case of the suction nozzle. In the example shown in FIG. 13, in addition to or instead of providing an exhaust port connected to the dust collector in the enclosure, a suction nozzle connected to the dust collector may be located inside the enclosure 170.

[0047] In the example of Figure 13, not only is exhaust vent 183 provided at bottom 172 of enclosure 170, but also air inlet 193 connected to blower 192 via hose 191. Air supplied to the inside of enclosure 170 through air inlet 193 causes floating fibrous dust to drift towards exhaust vent 183, facilitating the removal of the fibrous dust.

[0048] In another example, to prevent fiber dust from leaking out of the enclosure, a suction hood 184 can be placed above the chopping section 150, as shown in Figure 12. The suction hood 184 is connected to a dust collector 182 by, for example, a hose 181. In the example of FIG. 12, there is a gap between the enclosure 170 and the suction hood 184, but in one example, this gap can be eliminated. In the example of Figure 12, an air inlet 193 connected by a hose 191 to a blower 192 is also provided in the enclosure 170 to facilitate removal of fibrous dust. In the example shown in FIG. 12, in addition to using a suction hood, a suction nozzle connected to a dust collector may be placed inside the enclosure 170, or an exhaust port connected to a dust collector may be provided in the enclosure 170.

[0049] 16, a rod group 200 consisting of a plurality of rods arranged in parallel at intervals somewhat larger than the fiber length of the short carbon fiber bundles 20 is installed below the dispersion section 160. Each rod extends perpendicular to the T direction and horizontally or in a direction inclined preferably by 40° or less from the horizontal. The purpose of the rod group 200 is to prevent the orientation of the short carbon fiber bundles 20 from being biased toward the M direction in the carbon fiber mat 30 deposited on the first carrier film 41. In order to prevent fiber dust from settling on the rod group 200 and becoming cotton dust, an air supply nozzle 195 connected to an air compressor 194 is installed inside the enclosure 170. The outlet (air supply port) of the air supply nozzle 195 is directed toward the top of the rod group 200 in order to blow away fiber dust that has drifted onto the rod group 200. Such an air supply nozzle can be installed not only to prevent deposition on the rod group, but also to prevent deposition of fibrous dust in various locations inside the enclosure 170. For example, it is possible to investigate the locations where fibrous dust deposits when CF-SMC is manufactured without installing an air supply nozzle inside the enclosure 170, and then install an air supply nozzle with its outlet facing those locations.

[0050] 2, for example, by arranging a suction nozzle inside the lower part 172 of the enclosure, when the amount of fibrous dust floating toward the chopping section 150 is reduced, the upper part 171 of the enclosure 170 may be omitted. Alternatively, only the part of the upper part 171 of the enclosure 170 whose diameter decreases downward, including the connection part with the lower part 172, may be left, and the remaining part may be omitted.

[0051] 1, the impregnating machine 140 is of a type conventionally used in SMC manufacturing equipment, and is equipped with two belt conveyors for sandwiching the laminate 60 between two conveyor belts from above and below and conveying it, and rolls for sandwiching and pressurizing the laminate 60 together with the two conveyor belts. The laminate 60 is formed by laminating the first carrier film 41 and the second carrier film 42 together using a laminator 70 provided between the fiber mat deposition device 130 and the impregnating machine 140, with the first resin paste layer 51L, the carbon fiber mat 30, and the second resin paste layer 52L sandwiched between them.

[0052] 2. SMC manufacturing method The CF-SMC manufacturing method of the embodiment will be described below using the SMC manufacturing apparatus described in 1 above as an example. First, the continuous carbon fiber bundle 10 is drawn from a fiber package prepared in advance. The continuous carbon fiber bundle 10 may be drawn from an outside bobbin package attached to a creel, or may be drawn from an inside package from which the bobbin has been removed. The number of filaments in the continuous carbon fiber bundle 10, i.e., the number of carbon fiber filaments constituting the continuous carbon fiber bundle 10, is preferably within the range of 3K to 100K. Since K means 1000, 3K is 3000 and 100K is 100000. The number of filaments in the continuous carbon fiber bundle 10 can be, for example, 12K, 15K, 20K, 24K, 48K, 50K, 60K, etc. The continuous carbon fiber bundle 10 may be partially split into a plurality of sub-bundles in advance.

[0053] A plurality of continuous carbon fiber bundles 10 are aligned so as to be parallel to each other, and are supplied to a fiber mat depositing device 130 from a direction perpendicular to the T direction. In the chopping section 150 of the fiber mat depositing device 130, the continuous carbon fiber bundles 10 are cut into a predetermined length to form short carbon fiber bundles 20. The predetermined length is typically within a range of 10 to 60 mm, and may be, but is not limited to, 0.5 inches (approximately 1.3 cm), 1 inch (approximately 2.5 cm), 2 inches (approximately 5.1 cm), etc.

[0054] The short carbon fiber bundles 20 fall toward the dispersing section 160 below the chopping section 150, and are deposited on a first carrier film traveling below the fiber mat depositing device 130 while being dispersed by a first pin roll 161 and a second pin roll 162, thereby forming a carbon fiber mat 30. The treatment performed in the dispersing section 160 is not intended to untangle the short carbon fiber bundles 20. In a preferred example, the peripheral speeds at the pin tips of the first pin roll 161 and the second pin roll 162 are set so as to minimize the generation of fiber bundles with a filament count of less than 0.5K, and even if they are generated, so that the content of such fiber bundles in the carbon fiber mat 30 is less than 1% by weight.

[0055] For example, if the continuous carbon fiber bundle 10 is partially split into multiple sub-bundles and each sub-bundle has less than 2K filaments, the peripheral speeds at the pin tips of the first pin roll 161 and the second pin roll 162 can be set so as to minimize the occurrence of fiber bundles with less than 0.2K filaments, and even if they do occur, so that their content in the carbon fiber mat 30 is less than 1% by weight.

[0056] Rotating both the first pin roll 161 and the second pin roll 162 is advantageous in preventing the short carbon fiber bundle 20 from getting stuck between these two pin rolls. Preferably, as shown in FIG. 2, the first pin roll 161 rotates so that the pins 161b move from top to bottom on the side facing the second pin roll 162, and the second pin roll 162 rotates so that the pins 162b move from top to bottom on the side facing the first pin roll 161.

[0057] When the first pin roll 161 and the second pin roll 162 are rotated so that the pins move from top to bottom on the side facing the other pin roll, even if there is a weight distribution in the short carbon fiber bundles 20, the carbon fiber mat 30 is unlikely to have a front and back surface. This is because both heavy and light carbon fiber bundles pass through the narrow space between the two pin rolls and fall simultaneously onto the first carrier film 41. In other words, the positions at which the heavy short carbon fiber bundles fall and the positions at which the light short carbon fiber bundles fall are unlikely to be misaligned along the transport direction of the first carrier film.

[0058] Another reason why the first pin roll 161 and the second pin roll 162 are rotated so that the pins move from top to bottom on the side facing the other pin roll is to prevent a strong shear force from being applied to the short carbon fiber bundle 20 passing between these two pin rolls. A strong shear force causes fuzzing and loss of straightness of the carbon fiber bundle. To achieve this purpose more effectively, it is preferable to make the peripheral speeds at the pin tips of the first pin roll 161 and the second pin roll 162 equal.

[0059] Before the carbon fiber mat 30 is deposited, a first resin paste 51 is applied to one side of the first carrier film 41 that has been unwound from a roll using a first coater 110 . The first resin paste 51 is a thermosetting resin composition, and its base resin is, but is not limited to, vinyl ester resin (also known as epoxy acrylate resin), unsaturated polyester resin, epoxy resin, polyimide resin, maleimide resin, or phenolic resin. A mixed resin of vinyl ester resin and unsaturated polyester resin may also be used as the base resin. The first resin paste 51 may contain, as needed, a curing agent, a polymerization inhibitor, a thickener, a reactive diluent, a low-shrinkage agent, a flame retardant, an antibacterial agent, and the like.

[0060] A second resin paste 52 having the same composition as the first resin paste 51 is applied to one side of the second carrier film 42 using a second coater 120 . The second carrier film 42 is superimposed on the first carrier film 41, on which the carbon fiber mat 30 is placed, with the surface on which the second resin paste layer 52L is formed facing downward. The laminate 60 thus formed is pressed by the impregnation machine 140, whereby the carbon fiber mat 30 is impregnated with the first resin paste 51 and the second resin paste 52, to form a resin-impregnated carbon fiber mat. The resin-impregnated carbon fiber mat is wound up on a bobbin while being sandwiched between the first carrier film 41 and the second carrier film 42. The resin-impregnated carbon fiber mat wound up on the bobbin is thickened as necessary and then shipped as CF-SMC.

[0061] The dust collector 182 runs continuously throughout the production of CF-SMC. At least a portion of the fiber dust generated by the short carbon fiber bundles 20 coming into contact with the first pin roll 161 or the second pin roll 162 rises within the enclosure 170 and is then sucked and removed through the suction nozzle 180. By removing the fiber dust in this manner, the amount of cotton dust that can be harmful if mixed into the carbon fiber mat 30 is reduced.

[0062] 3. Summary of embodiments Preferred embodiments of the present invention include, but are not limited to: [Embodiment 1] A method for producing a sheet molding compound, comprising: (i) unrolling a carrier film from a roll and running the film on a conveying path so that its surface is horizontal; (ii) cutting continuous carbon fiber bundles with a chopper arranged above the conveying path to form short carbon fiber bundles; (iii) dispersing the short carbon fiber bundles using a dispersion roll arranged below the chopper while dropping them onto the carrier film running on the conveying path to deposit a carbon fiber mat on the carrier film; (iv) impregnating the carbon fiber mat with a thermosetting resin composition to form a resin-impregnated carbon fiber mat; and (v) simultaneously with depositing the carbon fiber mat, removing fiber dust generated from the short carbon fiber bundles due to contact with the dispersion roll using a dust collector. [Embodiment 2] A manufacturing method according to embodiment 1, in which a first pin roll and a second pin roll arranged side by side and having parallel rotation axes are used as the dispersion rolls. [Embodiment 3] A manufacturing method according to embodiment 2, in which the first pin roll is rotated so that the pins move from top to bottom on the side facing the second pin roll, and the second pin roll is rotated so that the pins move from top to bottom on the side facing the first pin roll. [Embodiment 4] A manufacturing method according to embodiment 2 or 3, wherein the sum of the maximum radius of the first pin roll and the maximum radius of the second pin roll is greater than the distance between the rotation axes of the first pin roll and the second pin roll. [Embodiment 5] The manufacturing method according to any one of embodiments 2 to 4, wherein the radius of the cylinder of each of the first pin roll and the second pin roll is at least half the maximum radius. [Embodiment 6] The manufacturing method according to any one of embodiments 2 to 5, wherein the peripheral speed at the tips of the pins of the first pin roll is equal to the peripheral speed at the tips of the pins of the second pin roll. [Embodiment 7] The production method according to any one of embodiments 1 to 6, wherein the carbon fiber mat contains 99% by weight or more of carbon fiber bundles with a filament count of 0.5K or more. [Embodiment 8] A manufacturing method according to any one of embodiments 1 to 7, in which before depositing the carbon fiber mat on the carrier film, a resin paste made of the thermosetting resin composition is applied to one side of the carrier film, and after depositing the carbon fiber mat, another carrier film having another resin paste made of the thermosetting resin composition applied to one side thereof is superimposed on the carrier film to form a laminate, and the laminate is further pressurized for the impregnation. [Embodiment 9] The manufacturing method according to any one of embodiments 1 to 8, wherein the removing step includes removing the fibrous dust while it is suspended in air.

[0063] [Embodiment 10] A method for producing a sheet molding compound using a fiber mat deposition device having a chopping section and a dispersion section located below the chopping section, the method comprising: (i) unrolling a carrier film from a roll and running it along a conveying path so that its surface is horizontal; (ii) cutting continuous carbon fiber bundles into short carbon fiber bundles in the chopping section of the fiber mat deposition device located above the conveying path; (iii) dispersing the short carbon fiber bundles in the dispersion section of the fiber mat deposition device using a dispersion roll having a rotation axis parallel to the T direction while dropping them onto the carrier film running along the conveying path, thereby depositing a carbon fiber mat on the carrier film; (iv) impregnating the carbon fiber mat with a thermosetting resin composition to form a resin-impregnated carbon fiber mat; and (v) simultaneously depositing the carbon fiber mat, removing fiber dust generated from the short carbon fiber bundles due to contact with the dispersion roll using one or more dust collectors, which may include a cyclone dust collector. [Embodiment 11] The manufacturing method according to embodiment 10, wherein the dispersion roll is a pin roll or a cage roll. [Embodiment 12] A manufacturing method according to embodiment 10 or 11, wherein the dispersion roll has n-fold rotational symmetry around the rotation axis (where n is an integer of 1 or greater, is finite, and preferably is 72 or less). [Embodiment 13] A manufacturing method according to any one of embodiments 10 to 12, wherein the dispersion section of the fiber mat deposition device is disposed inside an enclosure. [Embodiment 14] A manufacturing method according to embodiment 13, wherein at least one end of the shaft of the dispersion roll protrudes outside the enclosure through an opening provided in the enclosure. [Embodiment 15] A manufacturing method according to embodiment 13, in which both ends of the shaft of the dispersion roll each protrude outside the enclosure through an opening provided in the enclosure, and both of a pair of bearings supporting the shaft are positioned outside the enclosure. [Embodiment 16] A manufacturing method according to embodiment 14 or 15, in which a collar adjacent to the opening inside the enclosure is provided on the dispersion roll, and on a plane perpendicular to the T direction, the orthogonal projection of the opening falls within the outer contour of the orthogonal projection of the collar. [Embodiment 17] A manufacturing method according to embodiment 16, in which the gap between the collar and the enclosure is 5 mm or less. [Embodiment 18] A manufacturing method according to any one of embodiments 14 to 17, wherein an electric motor and a power transmission system for driving the dispersion roll are disposed outside the enclosure. [Embodiment 19] A manufacturing method according to any one of embodiments 13 to 18, wherein the enclosure is provided so that the chopping portion is disposed inside the enclosure. [Embodiment 20] A manufacturing method according to any one of embodiments 13 to 19, wherein a suction nozzle connected to at least one of the one or more dust collectors is disposed at the upper end of the enclosure. [Embodiment 21] A manufacturing method according to embodiment 19, wherein the upper end of the enclosure is sealed with a ceiling panel. [Embodiment 22] A manufacturing method according to embodiment 19, in which a suction hood connected to at least one of the one or more dust collectors is positioned above the chopping section. [Embodiment 23] A manufacturing method according to embodiment 22, in which there is no gap between the suction hood and the enclosure. [Embodiment 24] A manufacturing method according to any one of embodiments 13 to 23, wherein a suction nozzle connected to at least one of the one or more dust collectors is disposed inside the enclosure. [Embodiment 25] The manufacturing method according to any one of embodiments 13 to 24, wherein the enclosure is provided with an exhaust port, and the exhaust port is connected to at least one of the one or more dust collectors. [Embodiment 26] The manufacturing method according to any one of embodiments 13 to 25, further comprising supplying air to the inside of the enclosure simultaneously with depositing the carbon fiber mat. [Embodiment 27] A manufacturing method according to embodiment 26, in which either or both of a blower and an air compressor are used to supply the air. [Embodiment 28] A manufacturing method according to embodiment 26, in which an air intake connected to a blower or air compressor is positioned inside the enclosure. [Embodiment 29] A manufacturing method according to embodiment 26 or 28, wherein the enclosure is provided with an air inlet connected to a blower or air compressor. [Embodiment 30] A manufacturing method according to any one of embodiments 13 to 29, wherein the enclosure is formed of a metal plate and is grounded. [Embodiment 31] A manufacturing method according to any one of embodiments 10 to 30, in which before depositing the carbon fiber mat on the carrier film, a resin paste made of the thermosetting resin composition is applied to one side of the carrier film, and after depositing the carbon fiber mat, another carrier film having another resin paste made of the thermosetting resin composition applied to one side thereof is superimposed on the carrier film to form a laminate, and further the laminate is pressurized for the impregnation. [Embodiment 32] The manufacturing method according to any one of embodiments 10 to 31, wherein the carbon fiber mat contains 99% by weight or more of carbon fiber bundles having a filament count of 0.5K or more. [Embodiment 33] A manufacturing method according to any one of embodiments 10 to 32, wherein the removing step includes removing the fibrous dust while it is suspended in air.

[0064] [Embodiment 34] A fiber mat deposition device that is positioned above a conveying path and used to deposit carbon fiber mats on a carrier film that runs on the conveying path with its surface horizontal, comprising: a chopping section that cuts continuous carbon fiber bundles into short carbon fiber bundles; and a dispersion section that is positioned below the chopping section and disperses the short carbon fiber bundles using a dispersion roll having a rotation axis parallel to the T direction while causing them to fall onto the carrier film, wherein the dispersion section is positioned inside an enclosure and at least one end of the shaft of the dispersion roll protrudes outside the enclosure through an opening provided in the enclosure. [Embodiment 35] A fiber mat deposition device that is positioned above a conveying path and used to deposit carbon fiber mats on a carrier film that runs on the conveying path with its surface horizontal, comprising: a chopping section that cuts continuous carbon fiber bundles into short carbon fiber bundles; and a dispersion section that is positioned below the chopping section and disperses the short carbon fiber bundles using a dispersion roll having a rotation axis parallel to the T direction while causing them to fall onto the carrier film, wherein the dispersion section is positioned inside an enclosure, and both ends of the shaft of the dispersion roll each protrude outside the enclosure through openings provided in the enclosure, and both of a pair of bearings supporting the shaft are positioned outside the enclosure. [Embodiment 36] A fiber mat deposition device according to embodiment 34 or 35, wherein a collar adjacent to the opening inside the enclosure is provided on the dispersion roll, and on a plane perpendicular to the T direction, the orthogonal projection of the opening is within the outer contour of the orthogonal projection of the collar. [Embodiment 37] A fiber mat deposition device according to embodiment 36, in which the gap between the collar and the enclosure is 5 mm or less. [Embodiment 38] A fiber mat deposition device according to any one of embodiments 34 to 37, in which an electric motor and a power transmission system for driving the dispersion roll are arranged outside the enclosure. [Embodiment 39] A fiber mat deposition device according to any one of claims 34 to 38, wherein the enclosure is formed of a metal plate and is grounded. [Embodiment 40] A fiber mat deposition device having a chopping section that cuts continuous carbon fiber bundles into short carbon fiber bundles, and a dispersion section that is arranged below the chopping section and uses a dispersion roll to disperse the short carbon fiber bundles while causing them to fall onto a carrier film, wherein the dispersion section is arranged inside an enclosure that is formed from a metal plate and is grounded. [Embodiment 41] A fiber mat deposition device according to any one of embodiments 34 to 40, wherein the enclosure is configured so that the chopping section is positioned inside it. [Embodiment 42] A fiber mat deposition device according to any one of embodiments 34 to 41, in which a suction nozzle connected to a dust collector is disposed at the upper end of the enclosure. [Embodiment 43] A fiber mat deposition device according to embodiment 41, in which the upper end of the enclosure is sealed with a ceiling panel. [Embodiment 44] A fiber mat deposition device according to embodiment 41, in which a suction hood connected to a dust collector is positioned above the chopping section. [Embodiment 45] A fiber mat deposition device according to embodiment 44, in which there is no gap between the suction hood and the enclosure. [Embodiment 46] A fiber mat deposition device according to any one of embodiments 34 to 45, in which a suction nozzle connected to a dust collector is arranged inside the enclosure. [Embodiment 47] A fiber mat deposition device according to any one of embodiments 34 to 46, wherein the enclosure is provided with an exhaust port, and the exhaust port is connected to a dust collector. [Embodiment 48] A fiber mat deposition device according to any one of embodiments 34 to 47, which is arranged inside the enclosure and has an air intake connected to a blower or air compressor. [Embodiment 49] A fiber mat deposition device according to any one of embodiments 34 to 48, having an air inlet provided in the enclosure, the air inlet being connected to a blower or an air compressor. [Embodiment 50] A fiber mat depositing device according to any one of embodiments 34 to 49, wherein the dispersion roll is a pin roll or a cage roll. [Embodiment 51] A fiber mat deposition device according to any of embodiments 34 to 50, wherein the dispersion roll has n-fold rotational symmetry around the rotation axis (where n is an integer greater than or equal to 1, is finite, and preferably is 72 or less). [Embodiment 52] A method for producing a carbon fiber mat, comprising using a fiber mat deposition device according to any one of embodiments 34 to 51. [Embodiment 53] A method for producing a sheet molding compound, comprising depositing a carbon fiber mat using a fiber mat deposition device according to any one of embodiments 34 to 51, and impregnating the carbon fiber mat with a thermosetting resin composition. [Embodiment 54] Use of a fiber mat deposition device according to any one of embodiments 34 to 51 in the production of a sheet molding compound. [Embodiment 55] Use of a fiber mat deposition device according to any one of embodiments 34 to 51 in a sheet molding compound manufacturing device. [Embodiment 56] The use according to embodiment 55, wherein the sheet molding compound manufacturing apparatus comprises two coaters, a laminator, and an impregnation machine. [Embodiment 57] A sheet molding compound manufacturing apparatus equipped with a fiber mat deposition device according to any one of embodiments 34 to 51. [Embodiment 58] A sheet molding compound manufacturing apparatus according to embodiment 57, further comprising two coaters, a laminator, and an impregnation machine. [Embodiment 59] A sheet molding compound manufacturing apparatus comprising a fiber mat deposition device, two coating machines, a laminator, an impregnation machine, and one or more dust collectors which may include a cyclone dust collector. [Embodiment 60] A sheet molding compound manufacturing apparatus according to embodiment 59, wherein the fiber mat deposition device has a chopping section that cuts continuous carbon fiber bundles into short carbon fiber bundles, and a dispersion section that is positioned below the chopping section and uses a dispersion roll to disperse the short carbon fiber bundles while causing them to fall onto a carrier film. [Embodiment 61] A sheet molding compound manufacturing apparatus according to embodiment 60, wherein the dispersion roll is a pin roll or a cage roll. [Embodiment 62] A sheet molding compound manufacturing apparatus according to embodiment 60 or 61, wherein the dispersion roll has n-fold rotational symmetry around the rotation axis (where n is an integer greater than or equal to 1, is finite, and preferably is 72 or less). [Embodiment 63] A sheet molding compound manufacturing apparatus according to any one of embodiments 60 to 62, wherein the dispersion section of the fiber mat depositing device is arranged inside an enclosure. [Embodiment 64] A sheet molding compound manufacturing apparatus according to embodiment 63, wherein the enclosure is configured so that the chopping section is positioned inside it. [Embodiment 65] A sheet molding compound manufacturing apparatus according to embodiment 63 or 64, in which a suction nozzle connected to at least one of the one or more dust collectors is positioned at the upper end of the enclosure. [Embodiment 66] A sheet molding compound manufacturing apparatus according to embodiment 64, wherein the upper end of the enclosure is sealed with a ceiling panel. [Embodiment 67] A sheet molding compound manufacturing apparatus according to embodiment 65, in which a suction hood connected to at least one of the one or more dust collectors is positioned above the chopping section. [Embodiment 68] A sheet molding compound manufacturing apparatus according to embodiment 67, in which there is no gap between the suction hood and the enclosure. [Embodiment 69] A sheet molding compound manufacturing apparatus according to any one of embodiments 63 to 68, in which a suction nozzle connected to at least one of the one or more dust collectors is positioned inside the enclosure. [Embodiment 70] A sheet molding compound manufacturing apparatus according to any one of embodiments 63 to 69, wherein the enclosure is provided with an exhaust outlet, and the exhaust outlet is connected to at least one of the one or more dust collectors. [Embodiment 71] A sheet molding compound manufacturing apparatus according to any one of embodiments 63 to 70, which is arranged inside the enclosure and has an air intake port connected to a blower or air compressor. [Embodiment 72] A sheet molding compound manufacturing apparatus according to any one of embodiments 63 to 71, having an air intake provided in the enclosure, the air intake being connected to a blower or an air compressor. [Embodiment 73] A sheet molding compound manufacturing apparatus according to any one of embodiments 63 to 72, wherein the enclosure is formed of a metal plate and is grounded. [Embodiment 74] A method for producing CF-SMC, comprising using a sheet molding compound production apparatus according to any one of embodiments 57 to 73.

[0065] While the present invention has been described above with reference to specific embodiments, these embodiments are presented as examples and do not limit the scope of the present invention. Each embodiment described in this specification can be modified in various ways within the scope of the effects of the invention, and can be combined with features described in other embodiments within the scope of feasibility. [Industrial Applicability]

[0066] The CF-SMC manufactured using the method or apparatus according to the embodiment is used to mold CFRP products, for example, by compression molding. The applications of CFRP products manufactured using the CF-SMC are diverse, including parts for manned aircraft, unmanned aerial vehicles, automobiles, ships, railroad cars, and other transportation equipment, as well as sporting goods and leisure goods. [Explanation of symbols]

[0067] 10 continuous carbon fiber bundles 20 Short carbon fiber bundle 30 Carbon Fiber Mat 41 Daiichi Carrier Film 42 Secondary Carrier Film 51 Daiichi Resin Paste 51L First resin paste layer 52 Second resin paste 52L Second resin paste layer 60 laminate 70 Laminator 100 SMC manufacturing equipment 110 First Coating Machine 120 Second Coating Machine 130 Fiber mat deposition device 140 Impregnation machine 150 Chop section 151 Cutter Roll 152 Receiving roll (rubber roll) 153 Guide Roll 160 Dispersion section 161 First Pinroll 162 Second Pinroll 164 Cage Roll 170 Enclosure 171 Enclosure (Upper) 172 Enclosure (lower part) 173 Ceiling Panel 174 Grounding point 180 suction nozzle 180a Suction port forming part 181 Hose 182 Dust collector 184 Suction Hood 191 Hose 192 Blower 193 Air supply port 194 Air Compressor 195 Air Intake Nozzle 200 rods

Claims

1. (i) pulling out the carrier film from the roll and running it along the conveying path so that its surface is horizontal; (ii) cutting the continuous carbon fiber bundle with a chopper arranged above the conveying path to form short carbon fiber bundles; (iii) dropping the short carbon fiber bundles onto the carrier film traveling on the transport path while dispersing them using a dispersing roll arranged below the chopper, thereby depositing a carbon fiber mat on the carrier film; (iv) impregnating the carbon fiber mat with a thermosetting resin composition to form a resin-impregnated carbon fiber mat; and (v) removing fiber dust generated from the short carbon fiber bundles by contact with the dispersion roll using a dust collector while depositing the carbon fiber mat; 1. A method for producing a sheet molding compound, comprising:

2. The method according to claim 1 , wherein the dispersing rolls are a first pin roll and a second pin roll arranged side by side and having rotation axes parallel to each other.

3. The manufacturing method according to claim 2, wherein the first pin roll is driven to rotate so that pins move from top to bottom on the side facing the second pin roll, and the second pin roll is driven to rotate so that pins move from top to bottom on the side facing the first pin roll.

4. The manufacturing method according to claim 2 , wherein the sum of the maximum radius of the first pin roll and the maximum radius of the second pin roll is greater than the distance between the rotation axes of the first pin roll and the second pin roll.

5. The method of claim 2, wherein the radius of the cylinder of each of the first pin roll and the second pin roll is equal to or greater than half of the maximum radius.

6. The manufacturing method according to claim 2 , wherein the peripheral speed at the pin tips of the first pin roll is equal to the peripheral speed at the pin tips of the second pin roll.

7. The manufacturing method according to any one of claims 1 to 6, wherein the carbon fiber mat contains 99% by weight or more of carbon fiber bundles having a filament number of 0.5K or more.

8. 7. The manufacturing method according to claim 1, wherein before depositing the carbon fiber mat on the carrier film, a resin paste made of the thermosetting resin composition is applied to one side of the carrier film, and after depositing the carbon fiber mat, another carrier film having another resin paste made of the thermosetting resin composition applied to one side thereof is superimposed on the carrier film to form a laminate, and further the laminate is pressurized for the impregnation.

9. The manufacturing method according to any one of claims 1 to 6, wherein the removing step comprises removing the fibrous dust while it is suspended in air.

10. 1. A method for producing a sheet molding compound using a fiber mat laying device having a chopping section and a dispersing section disposed below the chopping section, comprising: (i) pulling out the carrier film from the roll and running it along the conveying path so that its surface is horizontal; (ii) cutting the continuous carbon fiber bundles into short carbon fiber bundles by the chopping section of the fiber mat depositing device arranged above the transport path; (iii) dropping the short carbon fiber bundles onto the carrier film traveling on the transport path while dispersing the short carbon fiber bundles using a dispersion roll having a rotation axis parallel to the T direction in the dispersion section of the fiber mat deposition device, thereby depositing a carbon fiber mat on the carrier film; (iv) impregnating the carbon fiber mat with a thermosetting resin composition to form a resin-impregnated carbon fiber mat; and (v) simultaneously depositing the carbon fiber mat, removing fiber dust generated from the short carbon fiber bundles by contact with the dispersion roll using one or more dust collectors; 1. A method for producing a sheet molding compound, comprising:

11. The method of claim 10, wherein the dispersion roll is a pin roll or a cage roll.

12. The method according to claim 10, wherein the dispersion roll has n-fold rotational symmetry about the rotation axis (where n is an integer of 1 or more, is finite, and is preferably 72 or less).

13. The method of claim 10, wherein the dispersion section of the fiber mat deposition device is located inside an enclosure.

14. The manufacturing method according to claim 13, wherein at least one end of the shaft of the dispersion roll protrudes outside the enclosure through an opening provided in the enclosure.

15. 14. The manufacturing method according to claim 13, wherein both ends of the shaft of the dispersion roll protrude outside the enclosure through openings formed in the enclosure, and both of a pair of bearings supporting the shaft are disposed outside the enclosure.

16. The manufacturing method according to claim 14, wherein a collar is provided on the dispersion roll adjacent to the opening inside the enclosure, and an orthogonal projection of the opening falls within the outline of the orthogonal projection of the collar on a plane perpendicular to the T direction.

17. The manufacturing method according to claim 16, wherein the gap between the collar and the enclosure is 5 mm or less.

18. 15. The method of claim 14, wherein an electric motor and power train for driving the dispersion roll are located outside the enclosure.

19. The manufacturing method according to claim 13 , wherein the enclosure is provided so that the chopping portion is disposed inside the enclosure.

20. The method of claim 13 , wherein a suction nozzle connected to at least one of the one or more dust collectors is disposed at an upper end of the enclosure.

21. The method of claim 19, wherein the top of the enclosure is sealed with a ceiling plate.

22. The manufacturing method according to claim 19, wherein a suction hood connected to at least one of the one or more dust collectors is disposed above the chopping section.

23. The method of claim 22, wherein there is no gap between the suction hood and the enclosure.

24. The manufacturing method according to claim 13, wherein a suction nozzle connected to at least one of the one or more dust collectors is disposed inside the enclosure.

25. The manufacturing method according to claim 13 , wherein the enclosure is provided with an exhaust port, the exhaust port being connected to at least one of the one or more dust collectors.

26. The method of claim 13 further comprising supplying air to the interior of the enclosure simultaneously with depositing the carbon fiber mat.

27. The method of claim 26, wherein the air supply is provided by using either or both of a blower and an air compressor.

28. 27. The method of claim 26, wherein an air inlet connected to a blower or air compressor is located inside the enclosure.

29. 27. The method of claim 26, wherein the enclosure is provided with an air inlet connected to a blower or air compressor.

30. The method of claim 13 , wherein the enclosure is formed of a metal plate and is grounded.

31. 31. The manufacturing method according to any one of claims 10 to 30, wherein before depositing the carbon fiber mat on the carrier film, a resin paste made of the thermosetting resin composition is applied to one side of the carrier film, and after depositing the carbon fiber mat, another carrier film having another resin paste made of the thermosetting resin composition applied to one side thereof is superimposed on the carrier film to form a laminate, and further the laminate is pressurized for the impregnation.

32. The manufacturing method according to any one of claims 10 to 30, wherein the carbon fiber mat has a content of carbon fiber bundles having a filament number of 0.5K or more of 99% by weight or more.

33. The manufacturing method according to any one of claims 10 to 30, wherein the removing comprises removing the fibrous dust while it is in suspension.

34. An apparatus for depositing a carbon fiber mat on a carrier film that is disposed above a conveying path and travels along the conveying path with its surface horizontal, comprising: a chopping section for cutting the continuous carbon fiber bundle into short carbon fiber bundles; a dispersion unit disposed below the chopping unit, for dispersing the short carbon fiber bundles using a dispersion roll having a rotation axis parallel to the T direction and causing the bundles to fall onto the carrier film; and The dispersion unit is disposed inside the enclosure, At least one end of the shaft of the distribution roll protrudes outside the enclosure through an opening provided in the enclosure, A fiber mat depositing device, wherein a collar is provided on the distribution roll adjacent to the opening inside the enclosure, and the orthogonal projection of the opening is within the outer contour of the orthogonal projection of the collar on a plane perpendicular to the T direction.

35. An apparatus for depositing a carbon fiber mat on a carrier film that is disposed above a conveying path and travels along the conveying path with its surface horizontal, comprising: a chopping section for cutting the continuous carbon fiber bundle into short carbon fiber bundles; a dispersion unit disposed below the chopping unit, for dispersing the short carbon fiber bundles using a dispersion roll having a rotation axis parallel to the T direction and causing the bundles to fall onto the carrier film; and The dispersion unit is disposed inside the enclosure, Both ends of the shaft of the distribution roll protrude outside the enclosure through openings provided in the enclosure, and both of a pair of bearings supporting the shaft are disposed outside the enclosure; A fiber mat depositing device, wherein a collar is provided on the distribution roll adjacent to the opening inside the enclosure, and the orthogonal projection of the opening is within the outer contour of the orthogonal projection of the collar on a plane perpendicular to the T direction.

36. 35. The fiber mat deposition apparatus of claim 34, wherein the gap between the collar and the enclosure is 5 mm or less.

37. A method for producing a carbon fiber mat, comprising using the fiber mat deposition device according to any one of claims 34 to 36.

38. A method for producing a sheet molding compound, comprising depositing a carbon fiber mat using the fiber mat depositing apparatus according to any one of claims 34 to 36, and impregnating the carbon fiber mat with a thermosetting resin composition.

39. An apparatus for producing a sheet molding compound, comprising the fiber mat depositing device according to any one of claims 34 to 36.

40. 40. The sheet molding compound manufacturing apparatus of claim 39, further comprising two coaters, a laminator, and an impregnator.

41. A method for producing CF-SMC, comprising using the sheet molding compound production apparatus according to claim 39.

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