Sheet molding compound manufacturing method, dispersion roller device, and sheet molding compound manufacturing device

Abstract

The purpose of the present invention is at least one among: preventing the contamination of an SMC production line; maintaining the cleanliness of mechanical elements included in an SMC production apparatus; preventing the failure of control devices equipped inside or around the SMC production apparatus; and preventing deterioration in work environments. A method for producing a sheet molding compound comprises (i) dropping short fiber bundles onto a traveling carrier film while dispersing the short fiber bundles using a dispersion roller device to deposit a fiber mat, and (ii) impregnating the fiber mat with a thermosetting resin composition, wherein: the dispersion roller device has a rotation-driven dispersion roll, a bearing, a first side cover, and a second side cover; the dispersion roller has a roll body and a roll body adjacent part; and the inner peripheral surface of the circular opening provided on each of the first side cover and the second side cover and the cylindrical peripheral surface of the roll body adjacent part face each other.

Description

[Technical field]

[0001] The present invention relates primarily to a method for making sheet molding compound (SMC). The present invention also relates to a dispersion roller device that can be suitably used in the production of SMC, and an SMC production apparatus including the same. This application claims priority based on Japanese Patent Application No. 2021-118818, filed in Japan on July 19, 2021, and Japanese Patent Application No. 2022-050649, filed in Japan on March 25, 2022, the contents of which are incorporated herein by reference. [Background technology]

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

[0003] CF-SMC is a type of prepreg, and in the manufacturing process, a continuous carbon fiber bundle is chopped with a chopper into short carbon fiber bundles, which are then dropped onto a running carrier film with a roughly horizontal surface to form a carbon fiber mat. CF-SMC is made by impregnating this carbon fiber mat with a thermosetting resin composition. In the production of CF-SMC, it has been proposed to provide a dispersing roll below a chopper in order to disperse short carbon fiber bundles that are dropped onto a carrier film (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] The present invention relates to a manufacturing technology for SMC that uses a dispersion roll to disperse short fiber bundles that are dropped onto a carrier film, and its main objective is to provide an improvement that is advantageous in at least one of preventing contamination of the SMC manufacturing line, maintaining the cleanliness of the mechanical elements contained in the SMC manufacturing equipment, preventing failure of control devices installed inside or around the SMC manufacturing equipment, and preventing deterioration of the working environment. 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]

[0006] According to one embodiment of the present invention, there is provided a method for producing a sheet molding compound, comprising: (i) dispersing short fiber bundles using a dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, while dropping the bundles onto a carrier film running with its surface approximately horizontal to deposit a fiber mat; and (ii) impregnating the fiber mat with a thermosetting resin composition, wherein in the dispersion roller device, the first side cover and the second side cover are disposed between the two bearings, and the dispersion roll has a roll body having a cylinder and a plurality of pins disposed on the circumferential surface of the cylinder, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end of the roll body in the axial direction, respectively, and the inner peripheral surface of a circular opening provided in the first side cover faces the cylindrical peripheral surface of the first roll body adjacent portion, and the inner peripheral surface of a circular opening provided in the second side cover faces the cylindrical peripheral surface of the second roll body adjacent portion.

[0007] According to another embodiment of the present invention, there is provided a method for producing a sheet molding compound, comprising: (i) dispersing a short fiber bundle using a dispersing roller device having a rotating dispersing roll, two bearings supporting the dispersing roll, a first side cover, and a second side cover, while dropping the short fiber bundle onto a carrier film running with its surface substantially horizontal to deposit a fiber mat; and (ii) impregnating the fiber mat with a thermosetting resin composition, wherein in the dispersing roller device, the first side cover and the second side cover are disposed between the two bearings. and the dispersion roll has a roll body having n-fold rotational symmetry (where n is an integer of 1 or more, is finite, and may be 72 or less) about the rotation axis, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, wherein an inner peripheral surface of a circular opening provided in the first side cover faces a cylindrical peripheral surface of the first roll body adjacent portion, and an inner peripheral surface of a circular opening provided in the second side cover faces a cylindrical peripheral surface of the second roll body adjacent portion.

[0008] According to yet another embodiment of the present invention, there is provided a dispersion roller device used for dispersing short fiber bundles to be dropped onto a carrier film in the production of a sheet molding compound, the dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, wherein the first side cover and the second side cover are arranged between the two bearings, the dispersion roll has a roll body having a cylinder and a plurality of pins arranged on the circumferential surface of the cylinder, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, and the inner surface of a circular opening provided in the first side cover faces the cylindrical peripheral surface of the first roll body adjacent portion, and the inner surface of a circular opening provided in the second side cover faces the cylindrical peripheral surface of the second roll body adjacent portion.

[0009] According to yet another embodiment of the present invention, there is provided a dispersion roller device used for dispersing short fiber bundles to be dropped onto a carrier film in the production of a sheet molding compound, the dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, wherein the first side cover and the second side cover are disposed between the two bearings, the dispersion roll has a roll body having n-fold rotational symmetry (where n is an integer of 1 or more, is finite, and may be 72 or less) around the rotation axis, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, and the inner surface of a circular opening provided in the first side cover faces the cylindrical peripheral surface of the first roll body adjacent portion, and the inner surface of a circular opening provided in the second side cover faces the cylindrical peripheral surface of the second roll body adjacent portion. Effect of the Invention

[0010] When producing SMC using a dispersion roll to disperse short fiber bundles to be dropped onto a carrier film, advantageous improvements are provided in terms of at least one of preventing contamination of the SMC production line, maintaining the cleanliness of the mechanical elements contained in the SMC production equipment, preventing failure of control devices installed inside or around the SMC production equipment, and preventing deterioration of the working environment. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of an SMC manufacturing apparatus. [Diagram 2] FIG. 2 is a schematic diagram of a dispersion roller device. [Diagram 3] FIG. 3 is a schematic diagram of a dispersion roll. [Figure 4] FIG. 4 shows an example of a pin arrangement on the circumferential surface of the roll body of the dispersion roll. [Diagram 5]FIG. 5 shows an example of a pin arrangement on the circumferential surface of the roll body of the dispersion roll. [Figure 6] FIG. 6 shows an example of a pin arrangement on the circumferential surface of the roll body of the dispersion roll. [Figure 7] FIG. 7 is a schematic diagram of a dispersion roll. [Figure 8] FIG. 8 is a schematic diagram of a dispersion roller device. [Figure 9] FIG. 9 is a schematic diagram for explaining one of the functions of the side cover. [Figure 10] FIG. 10 is a schematic diagram showing a part of the dispersion roller device. [Figure 11] FIG. 11 is a schematic diagram of a dispersion roller device. [Figure 12] FIG. 12 is a schematic diagram showing the positional relationship between two roll bodies in one embodiment of a dispersion roller device. [Figure 13] FIG. 13 is a schematic diagram for explaining one of the functions of the regulator plate. [Figure 14] FIG. 14 is a schematic diagram of a cage roll type roll body in one embodiment of the dispersion roller device. [Figure 15] FIG. 15 is a schematic diagram showing the roll body of the dispersion roll as viewed from the axial direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1.Sheet molding compound manufacturing equipment 1.1.Outline of the device One embodiment of the present invention relates to a sheet molding compound (SMC) production method, particularly to an SMC production apparatus that can be preferably used in a CF-SMC production method, which includes the following (i) and (ii): (i) Short fiber bundles are dispersed using a dispersion roll and dropped onto a carrier film traveling with the surface kept approximately horizontal to deposit a fiber mat. (ii) impregnating the fiber mat with a thermosetting resin composition.

[0013] A conceptual diagram of an SMC manufacturing apparatus according to one embodiment is shown in FIG. Referring to FIG. 1, an SMC production apparatus 10 includes a first coater 20, a second coater 30, a chopper 40, a dispersion roller device 50, and an impregnation device 60.

[0014] The first coater 20 is used to apply the first resin paste 5a to the first carrier film 4a to form the first resin paste layer 6a. The second coater 30 is used to apply the second resin paste 5b to the second carrier film 4b to form the second resin paste layer 6b.

[0015] The chopper 40 is disposed above the transport path of the first carrier film 4a and is used to cut the continuous fiber bundle 1 into short fiber bundles 2. The surface of the first carrier film 4a on the transport path is held substantially horizontally below the chopper 40. This is to prevent the fallen short fiber bundles 2 and the accumulated fiber mats 3 from moving due to gravity on the surface of the first carrier film 4a. The chopper 40 is of the type also used in conventional SMC manufacturing equipment, and is equipped with a cutter roll 41, a receiving roll (rubber roll) 42, and a guide roll 43. The rotation axes of the cutter roll 41, the receiving roll 42 and the guide roll 43 are all parallel to the T direction. The T direction is horizontal and perpendicular to the M direction. The M direction is the running direction of the first carrier film 4a. In FIG. 1, the T direction is perpendicular to the paper.

[0016] The dispersing roller device 50 is disposed below the chopper 40 in order to disperse the short fiber bundles 2 that fall onto the first carrier film 4a. A laminator 70 is disposed upstream of the impregnation machine 60 to bond the first carrier film 4a and the second carrier film 4b together. The first carrier film 4a and the second carrier film 4b are laminated together by a laminator 70 to form a laminate 7. In the laminate 7, the first resin paste layer 6a, the fiber mat 3, and the second resin paste layer 6b are sandwiched between the first carrier film 4a and the second carrier film 4b. The impregnation machine 60 is of a type that has been used in conventional SMC manufacturing equipment, and includes two upper and lower belt conveyors for sandwiching and conveying the laminate 7 between two conveyor belts, and rolls for pressing the laminate 7 together with the conveyor belts.

[0017] 1.2. Dispersion roller device 2 is a cutaway view seen from above of the dispersion roller device 50 included in the SMC production apparatus 10. The dispersion roller device 50 includes a dispersion roll 51 supported by a pair of bearings B1 and B2, a side cover (right) 53, and a side cover (left) 54. Both the side cover (right) 53 and the side cover (left) 54 are disposed between the bearing B1 and the bearing B2, so that the side covers and the bearings are not integrated. In FIG. 2, the mechanism for driving and rotating the dispersing roll 51, such as an electric motor and a power transmission system, is omitted (this is the same in the other drawings). In this specification, as shown in Figure 2, the first carrier film 4a runs from rear to front below the dispersion roller device 50, and when facing forward, the right hand is on the right side and the left hand is on the left side, and this is used to define the front, back, left and right of the dispersion roller device 50.

[0018] As shown in FIG. 3, the dispersion roll 51 has a roll body 510, a roll body adjacent portion (right) 513 and a roll body adjacent portion (left) 514 adjacent to one axial end (right end) and the other axial end (left end) of the roll body 510, respectively, and a shaft 511 that axially penetrates the roll body and the left and right roll body adjacent portions. The roll body 510 is of a pin roll type and has a cylinder 510a and a plurality of pins 510b arranged on the circumferential surface of the cylinder 510a. The roll body 510 and the shaft 511 of the dispersion roll 51 both have high rigidity and are made of a metal material such as stainless steel. When the dispersion roll 51 is rotated, the pins 510b move in the circumferential direction, so that the short fiber bundles 2 can be struck by the side surfaces of the pins 510b.

[0019] Both the roll body adjacent part (right) 513 and the roll body adjacent part (left) 514 have a cylindrical peripheral surface. The material of the roll body adjacent part may be different from that of the cylinder 510a, or it may be the same. When the material of the roll body adjacent part and the cylinder is different, the material of the roll body adjacent part may be metal (including alloy. The same applies below.) or may be resin in whole or in part. When the material of the roll body adjacent part and the cylinder is the same, the roll body adjacent parts 513, 514 may be formed integrally with the cylinder 510a.

[0020] The diameter of the cylindrical surface of the roll body adjacent parts 513, 514 is larger than the diameter of the shaft 511, and may be the same as or different from the diameter of the cylinder 510a. Preferably, the diameter of the cylindrical surface of the roll body adjacent parts 513, 514 is equal to or larger than the diameter of the cylinder 510a. In one example, the radius of the roll body adjacent parts 513, 514 is greater than the maximum radius r of the roll body 510. M The maximum radius r of the roll body 510 may be equal to or greater than the radius r of the roll body 510. M is the radius of a cylinder whose central axis coincides with the rotation axis of the roll body 510 and circumscribes the roll body 510. In the case of a pin roll type, the maximum radius of the roll body is equal to the distance from the rotation axis to the tip of the longest pin. The diameter of the roll body adjacent portions 513, 514 may be significantly smaller than the diameter of the cylinder 510a, but in that case, it may be disadvantageous in that the gaps between the cylinder 510a and the side covers 53, 54 are easily soiled with fibrous dust and are difficult to clean.

[0021] A preferred embodiment of the pin roll type roll body 510 is as follows. The diameter of the cylinder 510a is not limited, but may be, for example, 30 mm to 300 mm, or 60 mm to 150 mm. The larger the diameter of the cylinder 510a, the higher the peripheral speed at which the pins 510b move when the dispersing roll 51 is rotated, and the higher the ability to disperse the short fiber bundles 2. The pin 510b extends perpendicularly to the rotation axis (center axis) of the dispersion roll 51, and has, for example, a cylindrical shape, but is not limited thereto. The boundary between the end face and the peripheral surface of the pin 510b may be chamfered. The diameter of the pin 510b is not limited, but is, for example, 1 mm to 15 mm, may be 10 mm or less, and is preferably 5 mm or less. The length of the pin 510b, that is, the distance from the tip to the base of the pin, is not limited, but is, for example, 10 mm to 150 mm, may be 10 mm to 100 mm, or may be 10 mm to 50 mm. Preferably, all of the pins 510b have the same shape and dimensions as each other.

[0022] The arrangement of the pins 510b on the circumferential surface of the cylinder 510a is periodic. The arrangement of the pins 510b may overlap with the original position when shifted, for example, by 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, or may overlap with the original arrangement when shifted, for example, by 10°, 15°, 18°, 20°, 22.5°, 30°, 45°, 60°, 90°, 120°, or 180° in the circumferential direction. In the example of FIG. 3, the arrangement of the pins 510b overlaps with the original arrangement when shifted by 90° in the circumferential direction, so that the roll body 510 has 4-fold rotational symmetry around the rotation axis. For example, if the arrangement of the pins 510b overlaps with the original arrangement when shifted by 22.5° in the circumferential direction, the roll body has 16-fold rotational symmetry around the rotation axis.

[0023] In the dispersion roll 51 shown in Figure 3, when the peripheral surface of the cylinder 510a is developed into a plane, as shown in Figure 4, the pins 510b are arranged at lattice positions of a square lattice (shown by dashed lines) consisting of lattice lines parallel to the axial direction and lattice lines parallel to the circumferential direction. In another typical example, as shown in FIG. 5, the pins 510b may be arranged at lattice positions of an inclined square lattice (shown by dashed lines) consisting of lattice lines inclined from the axial direction and lattice lines parallel to the circumferential direction, or as shown in FIG. 6, the pins 510b may be arranged at each vertex of an equilateral triangle (shown by dashed lines) that fills a plane with one side parallel to the axial direction.

[0024] In one example, the shaft 511 may double as a cylinder, as shown in Fig. 7. However, this embodiment is disadvantageous in that when the dispersion roll 51 is rotated so as to optimize the peripheral speed at the tip of the pin 510b, fibrous dust is likely to adhere to areas where the peripheral speed is low, such as the surface of the shaft 511 and near the base of the pin 510b.

[0025] The side cover (right) 53 and the side cover (left) 54 are preferably made of metal plates, but are not limited to this. When metal plates are used, the thickness is, for example, 3 mm to 5 mm, and may be thinner or thicker depending on the required rigidity and strength. On both the right and left sides, the horizontal distance D from the side covers 53 and 54 to the nearest pin 510b is S may be 60 mm or less, 50 mm or less, 40 mm or less, 30 mm or less, 20 mm or less, or 10 mm or less.

[0026] 8, a circular opening (right) 53a is provided in the side cover (right) 53, and as shown in Fig. 2, the inner peripheral surface of this circular opening (right) 53a faces the cylindrical peripheral surface of the roll body adjacent part (right) 513 arranged immediately to the right of the roll body 510. Similarly, a circular opening (left) 54a is provided in the side cover (left) 54, and the inner peripheral surface of this circular opening (left) 54a faces the cylindrical peripheral surface of the roll body adjacent part (left) 514 arranged immediately to the left of the roll body 510. By adopting such a configuration, the short fiber bundles 2 and fiber dust generated by dispersing the short fiber bundles 2 by the dispersion roll 51 are less likely to leak out to the outside of the side covers 53, 54. This is advantageous in terms of at least one of preventing contamination of the SMC production line, maintaining the cleanliness of the mechanical elements included in the SMC production equipment, preventing failure of control devices installed inside or around the SMC production equipment, and preventing deterioration of the working environment. A gap G between the inner peripheral surface of the circular opening (right) 53a of the side cover (right) 53 and the cylindrical peripheral surface of the roll body adjacent portion (right) 513 1 , and a gap G between the inner peripheral surface of the circular opening (left) 54a of the side cover (left) 54 and the cylindrical peripheral surface of the roll body adjacent portion (left) 514 2 It will be obvious to those skilled in the art that the smaller the value, the greater the above effect.

[0027] Gap G 1 , G 2 is, for example, 10 mm or less, preferably 5 mm or less, more preferably 3 mm or less, and further preferably 1 mm or less, and may be 0.5 mm or less. 1 , G 2 is typically less than the length of pin 510b (or the length of the longest pin when not all pins have the same length), and is preferably less than 1 / 2, more preferably less than 1 / 5, and even more preferably less than 1 / 10 of that length.

[0028] The benefit of suppressing the leakage of fibrous dust to the outside of the side cover is particularly great when the short fiber bundles 2 are made of carbon fibers. This is because carbon fibers generally have a small filament diameter of less than 10 μm, generating fine fibrous dust that is easily suspended in the air. In addition, fibrous dust generated from carbon fibers is conductive and may cause problems in the operation of electrical and electronic devices.

[0029] By making one of the materials of the inner circumferential surfaces of the circular openings 53a, 54a and the cylindrical circumferential surfaces of the roll body adjacent portions 513, 514 metal and the other resin, it is possible to reduce the gap to approximately 0.2 mm. Suitable examples of resins here are resins that are generally used as materials for sliding bearings, such as polytetrafluoroethylene (PTFE), polyacetal, nylon, polyethylene, phenolic resin, polyimide, polyphenylene sulfide, polyether ether ketone, polyamide imide, etc.

[0030] The side cover 53 may be assembled from multiple parts, and the same is true for the side cover 54. 10, the side cover 53 is composed of a cover body 531 and a ring 532, and a ring 532 having a hole 532a with a smaller diameter than the main body opening 531a is fixed at the position of a main body opening 531a provided in the cover body 531. In this case, the hole 532a of the ring 532 corresponds to the circular opening 53a provided in the side cover 53, and the cylindrical peripheral surface of the roll body adjacent part (right) 513 faces the inner peripheral surface of the hole 532a of the ring 532.

[0031] In one example, when preparing the dispersion roller device 50, first the roll body adjacent part (right) 513 is inserted into the hole 532a of the ring 532, and then the ring 532 is fixed to the cover body 531. When fixing, the position of the ring 532 is adjusted so that the inner peripheral surface of the hole 532a does not come into contact with the roll body adjacent part (right) 513. To enable such adjustment, the position of the ring 532 when fixed to the cover body 531 is made variable within a plane perpendicular to the rotation axis of the dispersion roll 51. In this method, the gap G between the cylindrical peripheral surface of the roll body adjacent part 513 and the hole 532a of the ring 532 is adjusted. 1 This is particularly advantageous when preparing a small dispersion roller device 50.

[0032] The cover body 531 is preferably a metal plate. The material of the ring 532 may be the same as that of the cover body 531 or may be different. When the material of the ring 532 is resin, it is preferable that at least the cylindrical circumferential surface of the roll body adjacent portion 513 is made of metal. When the material of the ring 532 is metal, it is preferable that at least the cylindrical circumferential surface of the roll body adjacent portion 513 is made of resin. The roll body adjacent portion 513 may be composed of two or more parts, and for example, the portion including the cylindrical circumferential surface and the other portions may be made of different materials. The above description with reference to FIG. 10 can be applied in exactly the same way to the side cover (left) 54 and the roll body adjacent portion (left) 514.

[0033] In order to make the side cover 53 function more effectively, the vertical distance D from the rotation axis of the dispersing roll 51 to the upper edge of the side cover 53 is U is the maximum radius r of the roll body 510 of the dispersion roll 51 M Larger is preferable (see FIG. 8). Similarly, the vertical distance D from the rotation axis of the dispersion roll 51 to the lower edge of the side cover 53 L , the horizontal distance D from the rotation axis of the dispersion roll 51 to the front edge of the side cover 53 F , the horizontal distance D from the rotation axis of the dispersion roll 51 to the rear edge of the side cover 53 B , respectively, the maximum radius r M Larger is preferred. The same is true for the side cover 54. The vertical distances from the rotation axis of the dispersion roll 51 to the upper and lower edges of the side cover 54 and the horizontal distances to the front and rear edges are each determined by the maximum radius r M Larger is preferred.

[0034] 11, in one example, a front cover 55 may be disposed in front of a roll body 510 of a dispersion roll 51, and a rear cover 56 may be disposed behind the roll body 510. In the example of FIG. 11, two side covers 53, 54, the front cover 55, and the rear cover 56 are integrated to form an enclosure surrounding the roll body 510. There may be seams between the side covers 53, 54 and the front cover 55, as well as between the side covers 53, 54 and the rear cover 56.

[0035] 9, in one example, the side cover (right) 53 and the side cover (left) 54 can be made to act as regulators that regulate the width (dimension in the T direction) of the fiber mat 3 formed on the first carrier film 4a. In FIG. 9, the width of the fiber mat 3 deposited on the first carrier film 4a reflects the distance S between the lower edges of the two side covers 53, 54.

[0036] In another example, as shown in Fig. 13, two regulator plates 57 and 58 parallel to the M direction may be disposed between the side cover (right) 53 and the side cover (left) 54. The roll body 510 of the dispersion roll 51 passes through a circular hole formed in each of the regulator plates 57 and 58. The radius of this circular hole is the maximum radius r of the roll body 510. M The gap between the two regulator plates 57, 58 is only slightly larger than the gap between the first carrier film 4a, and almost all of the short fiber bundles 2 pass between the two regulator plates 57, 58 and fall onto the first carrier film 4a. The lower edges of the two regulator plates 57, 58 are brought sufficiently close to the upper surface of the first carrier film 4a so that the width of the fiber mat formed on the first carrier film 4a reflects the gap between the two regulator plates 57, 58. A small portion of the short fiber bundles 2 and fiber dust generated from the short fiber bundles 2 can pass through the circular holes formed in the regulator plates 57, 58, but are unlikely to leak out to the outside of the side covers 53, .

[0037] 1.3. First modified embodiment In a first modified embodiment, the number of dispersing rolls provided in the dispersing roller device is two or more. All of the two or more dispersing rolls are provided with a roll body adjacent portion having a cylindrical peripheral surface, and the cylindrical peripheral surface is configured to face the inner peripheral surface of the circular opening provided in the side cover.

[0038] In a preferred embodiment, the dispersing roller device can be provided with two dispersing rolls arranged in front and behind. An example of the positional relationship of the roll bodies when two dispersing rolls (a rear dispersing roll and a front dispersing roll) are arranged in this way is shown in Figure 12. In order to allow more short fiber bundles to be struck by the pins 5101b, 5102b provided on the roll bodies when passing between the roll body 5101 of the rear side distribution roll and the roll body 5102 of the front side distribution roll, the maximum radius r M1 and the maximum radius r of the roll body 5102 in the front dispersion roll M2 The sum of these two dispersion rolls is the distance between the rotation axes d 12 It is preferable that it is greater than . Maximum radius r of the rear dispersion roll body M1 and the cylinder radius r of the roll body 5102 of the front dispersion roll C2 and the cylinder radius r of the roll body 5101 of the rear dispersion roll C1 and the maximum radius r of the roll body of the front dispersion roll M2 The sum of both is the distance between the rotation axes of the two dispersion rolls, d 12 Less than.

[0039] The arrangement of FIG. 12 is by way of example and is not limiting. The arrangement of FIG. 12 is modified to have the maximum radius r of the roll body of the rear dispersion roll. M1 and the maximum radius r of the roll body of the front dispersion roll M2 The sum of these is taken as the distance between the rotation axes of the two dispersion rolls d 12 may be made equal to Furthermore, the maximum radius r of the roll body of the rear dispersion roll M1 and the maximum radius r of the roll body of the front dispersion roll M2 The sum of these is taken as the distance between the rotation axes of the two dispersion rolls d 12 However, the difference {d 12 -(r M1 +r M2 )} is preferably 10 mm or less, more preferably 5 mm or less.

[0040] When two dispersing rolls arranged in front of and behind are provided in a dispersing roller device, preferably, as shown in Figure 12, the rear dispersing roll is rotated so that the pin 5101b of the roll body moves from top to bottom on the side facing the front dispersing roll, and the front dispersing roll is rotated so that the pin 5102b of the roll body moves from top to bottom on the side facing the rear dispersing roll.

[0041] 1.4. Second Alternative Embodiment In a second modified embodiment, the roll body of the dispersing roll in the dispersing roller device is replaced from a pin roll type to a cage roll type. The cage roll type roll body has a structure in which multiple rods extending in the direction of the rotation axis are arranged at equal intervals on a cylindrical surface centered on the rotation axis. When the dispersion roll is rotated, the rods move in the circumferential direction, so that the short fiber bundles can be struck by the side of the rods. Instead of rods, taut wires can also be used.

[0042] The rod is preferably made of metal. There is no limitation on the cross-sectional shape of the rod, and it may be a circle, an ellipse, a square, a rectangle, a hexagon, or any other shape. The cage roll type roll body may have a structure in which the above-mentioned structure is multiplexed, i.e., a structure in which a plurality of rods extending in the direction of the rotation axis are arranged at equal intervals on each of two or more concentric cylindrical surfaces having different radii.

[0043] FIG. 14 shows an example of a dispersion roll having a cage roll type roll body that the dispersion roller device may have in the second modified embodiment. Referring to Figure 14, the dispersion roll 51 has a roll body 510, a roll body adjacent portion (right) 513 and a roll body adjacent portion (left) 514 adjacent to one axial end (right end) and the other axial end (left end) of the roll body 510, respectively, and a shaft 511 that axially penetrates the roll body and the left and right roll body adjacent portions. The roll body 510 is composed of six round bars 510c bridged between a support member 513a included in the roll body adjacent part (right) 513 and a support member 514a included in the roll body adjacent part (left) 514. The six round bars 510c are arranged at equal intervals on a cylindrical surface having the central axis of the shaft 511 as the center line, so that the roll body 510 has six-fold rotational symmetry.

[0044] The diameter of the round bar 510c is, for example, 3 mm or less, may be 1.5 mm or less, or may be 1 mm or more. Maximum radius r of roll body 510 M That is, the radius of a cylinder (cylinder circumscribing six round bars 510c) whose central axis coincides with the rotation axis of roll body 510 and circumscribing roll body 510 may be, for example, within the range of 100 mm or more and 200 mm or less, but is not limited thereto.

[0045] The roll body adjacent part (right) 513 is composed of a support member 513a and a disk 513b, and the roll body adjacent part (left) 514 is composed of a support member 514a and a disk 514b. When the dispersion roll 51 is incorporated into the dispersion roller device, the cylindrical peripheral surface of the disk 513b faces the inner peripheral surface of the circular opening (right) provided in the side cover (right), and the cylindrical peripheral surface of the disk 514b faces the inner peripheral surface of the circular opening (left) provided in the side cover (left).

[0046] The radius of the cylindrical circumferential surface of the disks 513b and 514b is the maximum radius r M It is preferable that the value is equal to or greater than the value. The diameter of the cylindrical surface of the disks 513b, 514b may be significantly smaller than the diameter of the support members 513a, 514a, but in that case, it may be disadvantageous in that the gaps between the support members 513a, 514a and the side covers 53, 54 are easily soiled with fibrous dust and are difficult to clean.

[0047] In one example, the support members 513a and 514a may also serve as the disks 513b and 514b. That is, when the dispersion roll 51 is incorporated into the dispersion roller device, the inner circumferential surface of the circular opening (right) provided in the side cover (right) may face the cylindrical circumferential surface of the support member 513a, and the inner circumferential surface of the circular opening (left) provided in the side cover (left) may face the cylindrical circumferential surface of the support member 514a. When the roll body 510 is of the cage roll type, the horizontal distance from each side cover 53, 54 to the roll body 510 can be 60 mm or less, 50 mm or less, 40 mm or less, 30 mm or less, 20 mm or less, or 10 mm or less.

[0048] 1.5. Other embodiments The roll body of the dispersion roll in the dispersion roller device is not limited to the pin roll type and the cage roll type, but may have n-fold rotational symmetry (where n is an integer of 1 or more and is finite) around the rotation axis. n is preferably 2 or more and 72 or less, may be 3 or more, and may be 36 or less, or 24 or less. For example, the roll body may be a triangular prism whose cross section perpendicular to the rotation axis is an equilateral triangle, or may have a shape in which such a triangular prism is twisted around the rotation axis. These are examples of roll bodies having three-fold rotational symmetry around the rotation axis. As shown in FIG. 15, when such a roll body is rotated, all three sides move in the circumferential direction except for the points where the normal direction coincides with the radial direction of the roll body.

[0049] The maximum radius of the roll body is defined as the radius of a cylinder that has the rotation axis of the roll body as its centerline and circumscribes the roll body, regardless of the structure of the roll body. The radius of the cylindrical circumferential surface of the roll body adjacent portions adjacent to one end and the other end in the axial direction of the roll body can preferably be equal to or greater than the maximum radius of the roll body 510.

[0050] 2. Manufacturing method of sheet molding compound The procedure for producing SMC using the SMC production apparatus 10 will be described below. First, the continuous fiber bundle 1 is drawn from a fiber package prepared in advance. The continuous fiber bundle 1 may be drawn from a bobbin package attached to a creel by external drawing, or may be drawn from a package from which the bobbin has been removed by internal drawing. The continuous fiber bundle 1 is preferably made of carbon fiber, but is not limited thereto, and may be made of fibers other than carbon fiber, such as glass fiber or aramid fiber. When the continuous fiber bundle 1 is a carbon fiber bundle, the number of filaments per bundle is not limited, but may be, for example, 3000 to 100000. The continuous fiber bundle may be partially split in advance into a plurality of sub-bundles.

[0051] A plurality of continuous fiber bundles 1 are aligned so as to be parallel to each other, and are then fed to a chopper 40 from a direction perpendicular to the T direction, where they are cut into short fiber bundles 2. When producing CF-SMC, the fiber length of the short fiber bundle 2 is, for example, 5 mm to 100 mm, preferably 10 mm to 60 mm, and more preferably 10 mm to 30 mm, and can typically be, but is not limited to, 0.5 inch (about 1.3 cm), 1 inch (about 2.5 cm), 2 inches (about 5.1 cm), etc. In a modified example, instead of producing the short fiber bundle 2 from the continuous fiber bundle 1 on the spot using the chopper 40, the short fiber bundle 2 produced in advance in a separate process may be dropped from above toward the dispersion roller device 50 using a hopper or the like.

[0052] The short fiber bundles 2 are dispersed by a dispersion roller device 50 and fall onto the first carrier film 4 a to form a fiber mat 3 . When producing CF-SMC, the operating conditions of the dispersion roller device 50 (the rotation speed of the dispersion roll 51) can be preferably set so as to prevent fiber bundles and single filaments having 500 or less filaments from being generated, or, even if they are generated, so that their content in the fiber mat 3 is less than 1 weight %. Even when producing CF-SMC, in an example in which the continuous fiber bundle 1 is a carbon fiber bundle that has been partially split into a plurality of sub-bundles in advance and each sub-bundle has a filament count of less than 2K, the operating conditions of the dispersion roller device 50 can be set so as to minimize the generation of fiber bundles with a filament count of less than 0.2K, and even if they are generated, so that the content of such fiber bundles in the fiber mat 3 is less than 1 weight %. When producing CF-SMC, it is also desirable to take into consideration, when determining the operating conditions of the dispersion roller device 50, that the basis weight of the fiber mat 3 does not become significantly uneven due to the air current generated by the rotation of the dispersion roll 51.

[0053] In an embodiment in which the dispersion roller device 50 has two pin roll type dispersion rolls arranged so that their rotation axes are parallel to each other, when each dispersion roll is rotated so that the pins move from top to bottom on the side facing the other dispersion roll, as shown in Figure 12, the fiber mat 3 is less likely to have a front and back surface even if there is a weight distribution in the short fiber bundles 2. This is because both the heavy short fiber bundle and the light short fiber bundle pass through the gap between the roll bodies of the two dispersion rolls and fall onto the first carrier film, in other words, the position where the heavy short fiber bundle falls and the position where the light short fiber bundle falls are unlikely to be misaligned along the running direction of the first carrier film.

[0054] Before the fibre mat 3 is deposited, the first carrier film 4a is coated with a first resin paste 5a by means of a first coater 20. The first resin paste 5a is a thermosetting resin composition, and its base resin is, but is not limited to, for example, vinyl ester resin (also called epoxy acrylate resin), unsaturated polyester resin, epoxy resin, polyimide resin, maleimide resin, or phenol resin. A mixed resin of vinyl ester resin and unsaturated polyester resin may be used as the base resin. The first resin paste 5a may contain, as necessary, a hardener, a polymerization inhibitor, a thickener, a reactive diluent, a low shrinkage agent, a flame retardant, an antibacterial agent, etc.

[0055] In a separate step, a second coater 30 is used to apply a second resin paste 5b having the same composition as the first resin paste 5a onto a second carrier film 4b. The second carrier film 4b is superimposed on the first carrier film 4a having the fiber mat 3 placed on its upper surface, with the side on which the second resin paste 5b is applied facing down, and the laminate 7 thus formed is pressed in an impregnation machine 60, whereby the fiber mat 3 is impregnated with the thermosetting resin composition to form a resin-impregnated fiber mat.

[0056] The resin-impregnated fiber mat is sandwiched between the first carrier film 4a and the second carrier film 4b and wound up on a bobbin. The resin-impregnated fiber mat is then subjected to a process of thickening to obtain a sheet molding compound.

[0057] Sheet molding compounds are used to mold fiber-reinforced plastic (FRP) products, for example, by compression molding. In particular, CFRP products that can be manufactured using CF-SMC have a wide range of applications, including parts for aircraft, unmanned aerial vehicles, automobiles, ships, and other types of transportation equipment, as well as sporting goods and leisure goods.

[0058] 3. Summary of the embodiment Preferred embodiments of the present invention include, but are not limited to, the following. [Embodiment 1] A method for producing a sheet molding compound, comprising: (i) dispersing short fiber bundles using a dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, while dropping the bundles onto a carrier film traveling with its surface approximately horizontal to deposit a fiber mat; and (ii) impregnating the fiber mat with a thermosetting resin composition, wherein in the dispersion roller device, the first side cover and the second side cover are disposed between the two bearings, and the dispersion roll has a roll body having a cylinder and a plurality of pins disposed on the circumferential surface of the cylinder, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end of the roll body in the axial direction, respectively, and an inner peripheral surface of a circular opening provided in the first side cover faces a cylindrical peripheral surface of the first roll body adjacent portion, and an inner peripheral surface of a circular opening provided in the second side cover faces a cylindrical peripheral surface of the second roll body adjacent portion. [Embodiment 2] A manufacturing method according to embodiment 1, wherein the diameter of the cylindrical circumferential surface of the first roll body adjacent portion and the diameter of the cylindrical circumferential surface of the second roll body adjacent portion are equal to the diameter of the cylinder. [Embodiment 3] A manufacturing method according to embodiment 1, wherein the diameter of the cylindrical circumferential surface of the first roll body adjacent portion and the diameter of the cylindrical circumferential surface of the second roll body adjacent portion are larger than the diameter of the cylinder. [Embodiment 4] The manufacturing method according to any one of embodiments 1 to 3, wherein the diameter of the cylinder is 30 mm to 300 mm, preferably 60 mm to 150 mm. [Embodiment 5] A manufacturing method according to any one of embodiments 1 to 4, wherein the dispersion roll has a shaft axially penetrating the roll body, the first roll body adjacent portion, and the second roll body adjacent portion, and the diameter of the shaft is smaller than the diameter of the cylinder. [Embodiment 6] A manufacturing method according to any one of embodiments 1 to 5, wherein the gap between the inner surface of the circular opening in the first side cover and the cylindrical peripheral surface of the first roll body adjacent portion, and the gap between the inner surface of the circular opening in the second side cover and the cylindrical peripheral surface of the second roll body adjacent portion are both smaller than the length of the longest pin among the multiple pins. [Embodiment 7] The manufacturing method according to any one of embodiments 1 to 6, wherein the dispersion roller device has, as the dispersion roll, a first dispersion roll and a second dispersion roll arranged so that their rotation axes are parallel to each other. [Embodiment 8] A manufacturing method according to embodiment 7, wherein the first dispersion roll is rotationally driven so that the pins on the roll body on the side facing the second dispersion roll move from top to bottom, and the second dispersion roll is rotationally driven so that the pins on the roll body on the side facing the first dispersion roll move from top to bottom. [Embodiment 9] A manufacturing method according to embodiment 7 or 8, wherein the sum of the maximum radius of the roll body of the first dispersion roll and the maximum radius of the roll body of the second dispersion roll is greater than the distance between the rotation axes of the first dispersion roll and the second dispersion roll. [Embodiment 10] A method for producing a sheet molding compound, comprising: (i) dispersing a short fiber bundle using a dispersing roller device having a rotating dispersing roll, two bearings supporting the dispersing roll, a first side cover, and a second side cover, while dropping the bundle onto a carrier film running with its surface approximately horizontal to deposit a fiber mat; and (ii) impregnating the fiber mat with a thermosetting resin composition, wherein in the dispersing roller device, the first side cover and the second side cover are disposed between the two bearings. and the dispersion roll has a roll body having n-fold rotational symmetry (where n is an integer of 1 or more, is finite, and may be 72 or less) about the rotation axis, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, wherein an inner peripheral surface of a circular opening provided in the first side cover faces a cylindrical peripheral surface of the first roll body adjacent portion, and an inner peripheral surface of a circular opening provided in the second side cover faces a cylindrical peripheral surface of the second roll body adjacent portion. [Embodiment 11] A manufacturing method according to embodiment 10, wherein the radius of the cylindrical circumferential surface of the first roll body adjacent portion and the radius of the cylindrical circumferential surface of the second roll body adjacent portion are equal to or greater than the maximum radius of the roll body. [Embodiment 12] A manufacturing method according to embodiment 10 or 11, wherein the roll body is a cage roll type and has a plurality of rods or wires stretched between a support member included in the first roll body adjacent portion and a support member included in the second roll body adjacent portion. [Embodiment 13] A manufacturing method according to any one of embodiments 1 to 12, wherein the material of the inner circumferential surface of the circular opening provided in each of the first side cover and the second side cover is resin, and the material of the cylindrical circumferential surface of each of the first roll body adjacent portion and the second roll body adjacent portion is metal. [Embodiment 14] A manufacturing method according to any one of embodiments 1 to 12, wherein the material of the inner circumferential surface of the circular opening provided in each of the first side cover and the second side cover is metal, and the material of the cylindrical circumferential surface of each of the first roll body adjacent portion and the second roll body adjacent portion is resin. [Embodiment 15] A manufacturing method according to embodiment 13 or 14, wherein the resin includes any one selected from tetrafluoroethylene resin, polyacetal, nylon, polyethylene, phenolic resin, polyimide, polyphenylene sulfide, polyether ether ketone, and polyamide imide. [Embodiment 16] A manufacturing method according to any one of embodiments 1 to 15, wherein the gap between the inner surface of the circular opening in the first side cover and the cylindrical peripheral surface of the first roll body adjacent portion, and the gap between the inner surface of the circular opening in the second side cover and the cylindrical peripheral surface of the second roll body adjacent portion are all 10 mm or less, 5 mm or less, 3 mm or less, 1 mm or less, or 0.5 mm or less. [Embodiment 17] A manufacturing method according to any one of embodiments 1 to 16, wherein the dispersion roller device satisfies at least one of the following conditions (A) and (B): (A) The first side cover comprises a first cover body and a first ring fixed to the first cover body, and a hole in the first ring corresponds to the circular opening provided in the first side cover. (B) The second side cover comprises a second cover body and a second ring fixed to the second cover body, and a hole in the second ring corresponds to the circular opening provided in the second side cover. [Embodiment 18] A manufacturing method according to embodiment 17, further comprising preparing the dispersion roller device, wherein when preparing the dispersion roller device, when the dispersion roller device satisfies the condition (A), the first roll body adjacent part is inserted into the hole of the first ring and then the first ring is fixed to the first cover body, and when the dispersion roller device satisfies the condition (B), the second roll body adjacent part is inserted into the hole of the second ring and then the second ring is fixed to the second cover body. [Embodiment 19] A manufacturing method of embodiment 17 or 18, wherein when the dispersion roller device satisfies condition (A), the position of the first ring when fixed to the first cover body is variable within a plane perpendicular to the rotation axis of the dispersion roll, and when the dispersion roller device satisfies condition (B), the position of the second ring when fixed to the second cover body is variable within a plane perpendicular to the rotation axis of the dispersion roll. [Embodiment 20] A manufacturing method according to any of embodiments 1 to 19, wherein the vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the first side cover, the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the first side cover, the vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the second side cover, and the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the second side cover are greater than the maximum radius of the roll body. [Embodiment 21] A manufacturing method according to any one of embodiments 1 to 20, wherein a pair of regulator plates are arranged between the first side cover and the second side cover parallel to the running direction of the carrier film, and the roll body of the dispersion roll is passed through both an opening on one of the pair of regulator plates and an opening on the other of the pair of regulator plates. [Embodiment 22] A manufacturing method according to embodiment 21, in which the opening of one of the pair of regulator plates and the opening of the other are both circular and have a radius larger than the maximum radius of the roll body. [Embodiment 23] The production method according to any one of embodiments 1 to 22, wherein the short fiber bundles are made of carbon fibers. [Embodiment 24] A dispersion roller device used for dispersing short fiber bundles to be dropped onto a carrier film in the production of sheet molding compounds, the device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, wherein the first side cover and the second side cover are arranged between the two bearings, and the dispersion roll has a roll body having a cylinder and a plurality of pins arranged on the circumferential surface of the cylinder, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, and the inner surface of a circular opening provided in the first side cover faces the cylindrical peripheral surface of the first roll body adjacent portion, and the inner surface of a circular opening provided in the second side cover faces the cylindrical peripheral surface of the second roll body adjacent portion. [Embodiment 25] An apparatus according to embodiment 24, wherein the diameter of the cylindrical circumferential surface of the first roll body adjacent portion and the diameter of the cylindrical circumferential surface of the second roll body adjacent portion are equal to the diameter of the cylinder. [Embodiment 26] An apparatus according to embodiment 24, wherein the diameter of the cylindrical circumferential surface of the first roll body adjacent portion and the diameter of the cylindrical circumferential surface of the second roll body adjacent portion are larger than the diameter of the cylinder. [Embodiment 27] An apparatus according to any one of embodiments 24 to 26, wherein the diameter of the cylinder is 30 mm to 300 mm, preferably 60 mm to 150 mm. [Embodiment 28] An apparatus relating to any of embodiments 24 to 27, wherein the dispersion roll has a shaft axially penetrating the roll body, the first roll body adjacent portion, and the second roll body adjacent portion, and the diameter of the shaft is smaller than the diameter of the cylinder. [Embodiment 29] An apparatus relating to any one of embodiments 24 to 28, wherein the gap between the inner surface of the circular opening in the first side cover and the cylindrical peripheral surface of the first roll body adjacent portion, and the gap between the inner surface of the circular opening in the second side cover and the cylindrical peripheral surface of the second roll body adjacent portion are both smaller than the length of the longest pin among the multiple pins. [Embodiment 30] An apparatus according to any one of embodiments 24 to 29, wherein the dispersion roller device has, as the dispersion rolls, a first dispersion roll and a second dispersion roll arranged so that their rotation axes are parallel to each other. [Embodiment 31] An apparatus relating to embodiment 30, wherein the first dispersion roll is rotationally driven so that the pins on the roll body on the side facing the second dispersion roll move from top to bottom, and the second dispersion roll is rotationally driven so that the pins on the roll body on the side facing the first dispersion roll move from top to bottom. [Embodiment 32] An apparatus according to embodiment 30 or 31, wherein the sum of the maximum radius of the roll body of the first dispersion roll and the maximum radius of the roll body of the second dispersion roll is greater than the distance between the rotation axes of the first dispersion roll and the second dispersion roll. [Embodiment 33] A dispersion roller device used for dispersing short fiber bundles to be dropped onto a carrier film in the production of a sheet molding compound, the dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, wherein the first side cover and the second side cover are disposed between the two bearings, and the dispersion roll has a roll body having n-fold rotational symmetry (where n is an integer greater than or equal to 1, is finite, and may be 72 or less) about the rotation axis, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, and the inner surface of a circular opening provided in the first side cover faces the cylindrical peripheral surface of the first roll body adjacent portion, and the inner surface of a circular opening provided in the second side cover faces the cylindrical peripheral surface of the second roll body adjacent portion. [Embodiment 34] An apparatus according to embodiment 33, wherein the radius of the cylindrical circumferential surface of the first roll body adjacent portion and the radius of the cylindrical circumferential surface of the second roll body adjacent portion are equal to or greater than the maximum radius of the roll body. [Embodiment 35] An apparatus according to embodiment 33 or 34, wherein the roll body is a cage roll type and has a plurality of rods or wires stretched between a support member included in the first roll body adjacent portion and a support member included in the second roll body adjacent portion. [Embodiment 36] An apparatus according to any one of embodiments 24 to 35, wherein the material of the inner circumferential surface of the circular opening provided in each of the first side cover and the second side cover is resin, and the material of the cylindrical circumferential surface of each of the first roll body adjacent portion and the second roll body adjacent portion is metal. [Embodiment 37] An apparatus according to any one of embodiments 24 to 35, wherein the material of the inner circumferential surface of the circular opening provided in each of the first side cover and the second side cover is metal, and the material of the cylindrical circumferential surface of each of the first roll body adjacent portion and the second roll body adjacent portion is resin. [Embodiment 38] An apparatus according to embodiment 36 or 37, wherein the resin includes any one selected from tetrafluoroethylene resin, polyacetal, nylon, polyethylene, phenolic resin, polyimide, polyphenylene sulfide, polyether ether ketone, and polyamide imide. [Embodiment 39] An apparatus relating to any of embodiments 24 to 38, wherein the gap between the inner surface of the circular opening in the first side cover and the cylindrical peripheral surface of the first roll body adjacent portion, and the gap between the inner surface of the circular opening in the second side cover and the cylindrical peripheral surface of the second roll body adjacent portion are all 10 mm or less, 5 mm or less, 3 mm or less, 1 mm or less, or 0.5 mm or less. [Embodiment 40] An apparatus according to any one of embodiments 24 to 39, which satisfies at least one of the following conditions (A) and (B): (A) The first side cover comprises a first cover body and a first ring fixed to the first cover body, and a hole in the first ring corresponds to the circular opening provided in the first side cover. (B) The second side cover comprises a second cover body and a second ring fixed to the second cover body, and a hole in the second ring corresponds to the circular opening provided in the second side cover. [Embodiment 41] An apparatus relating to embodiment 40, wherein, when condition (A) is satisfied, the position of the first ring when fixed to the first cover body is variable within a plane perpendicular to the rotation axis of the dispersion roll, and, when condition (B) is satisfied, the position of the second ring when fixed to the second cover body is variable within a plane perpendicular to the rotation axis of the dispersion roll. [Embodiment 42] An apparatus relating to any of embodiments 24 to 41, wherein the vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the first side cover, the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the first side cover, the vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the second side cover, and the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the second side cover are greater than the maximum radius of the roll body. [Embodiment 43] An apparatus relating to any of embodiments 24 to 42, wherein a pair of regulator plates are arranged between the first side cover and the second side cover parallel to the running direction of the carrier film, and the roll body of the dispersion roll is passed through both an opening in one of the pair of regulator plates and an opening in the other of the pair of regulator plates. [Embodiment 44] An apparatus according to embodiment 43, in which the openings of one of the pair of regulator plates and the openings of the other of the pair of regulator plates are both circular and have a radius larger than the maximum radius of the roll body. [Embodiment 45] Use of an apparatus according to any one of embodiments 24 to 44 in a sheet molding compound manufacturing apparatus. [Embodiment 46] The use according to embodiment 45, wherein the sheet molding compound manufacturing apparatus comprises two coaters, a laminator, and an impregnation machine. [Embodiment 47] The use according to embodiment 46, wherein the sheet molding compound manufacturing apparatus further comprises a chopper. [Embodiment 48] A sheet molding compound manufacturing apparatus comprising an apparatus according to any one of embodiments 24 to 44. [Embodiment 49] A sheet molding compound manufacturing apparatus according to embodiment 48, further comprising two coaters, a laminator, and an impregnation machine. [Embodiment 50] A sheet molding compound manufacturing apparatus according to embodiment 49, further comprising a chopper. [Embodiment 51] A method for producing a sheet molding compound using a sheet molding compound production apparatus according to any one of embodiments 48 to 50. [Embodiment 52] A manufacturing method relating to embodiment 51, which is a method for manufacturing CF-SMC.

[0059] Although the present invention has been described above with reference to specific embodiments, 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 modified in various ways without departing from the spirit of the invention, and can be combined with features described in other embodiments within the scope of feasibility. [Explanation of symbols]

[0060] 1. Continuous fiber bundle 2 Short fiber bundles 3 Fiber mat 4a First Carrier Film 4b Second carrier film 5a First Resin Paste 5b Second resin paste 6a First resin paste layer 6b Second resin paste layer 7 Laminate 10 SMC manufacturing equipment 20 First Coating Machine 30 Second Coating Machine 40 Chopper 50 Dispersion roller device 51 Distributed Roll 510 Roll body 511 Shaft 513, 514 Roll body adjacent part 53, 54 Side cover 531 Cover body 532 Ring 55 Front cover 56 Rear cover 60 Impregnation machine 70 Laminator

Claims

1. A method for producing a sheet molding compound, comprising: (i) dispersing short fiber bundles using a dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, while dropping the bundles onto a carrier film traveling with its surface approximately horizontal to deposit a fiber mat; and (ii) impregnating the fiber mat with a thermosetting resin composition, wherein in the dispersion roller device, the first side cover and the second side cover are disposed between the two bearings, and the dispersion roll has a roll body having a cylinder and a plurality of pins disposed on a circumferential surface of the cylinder, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end of the roll body in the axial direction, respectively, and an inner peripheral surface of a circular opening provided in the first side cover faces a cylindrical peripheral surface of the first roll body adjacent portion, and an inner peripheral surface of a circular opening provided in the second side cover faces a cylindrical peripheral surface of the second roll body adjacent portion.

2. The manufacturing method according to claim 1 , wherein a diameter of the cylindrical peripheral surface of the first roll body adjacent portion and a diameter of the cylindrical peripheral surface of the second roll body adjacent portion are equal to a diameter of the cylinder.

3. The manufacturing method according to claim 1 , wherein a diameter of the cylindrical peripheral surface of the first roll body adjacent portion and a diameter of the cylindrical peripheral surface of the second roll body adjacent portion are larger than a diameter of the cylinder.

4. The method according to any one of claims 1 to 3, wherein the diameter of the cylinder is from 30 mm to 300 mm.

5. The manufacturing method according to any one of claims 1 to 4, wherein the dispersion roll has a shaft that axially penetrates the roll body, the first roll body adjacent portion, and the second roll body adjacent portion, and the diameter of the shaft is smaller than the diameter of the cylinder.

6. 6. The manufacturing method according to claim 1, wherein a gap between an inner circumferential surface of the circular opening provided in the first side cover and the cylindrical circumferential surface of the first roll body adjacent portion, and a gap between an inner circumferential surface of the circular opening provided in the second side cover and the cylindrical circumferential surface of the second roll body adjacent portion are both smaller than a length of the longest pin among the plurality of pins.

7. The manufacturing method according to any one of claims 1 to 6, wherein the dispersion roller device has, as the dispersion roll, a first dispersion roll and a second dispersion roll arranged so that their rotation axes are parallel to each other.

8. The manufacturing method described in claim 7, wherein the first dispersion roll is rotationally driven so that the pins on the roll body on the side facing the second dispersion roll move from top to bottom, and the second dispersion roll is rotationally driven so that the pins on the roll body on the side facing the first dispersion roll move from top to bottom.

9. The manufacturing method according to claim 7 or 8, wherein a sum of a maximum radius of the roll body of the first dispersion roll and a maximum radius of the roll body of the second dispersion roll is greater than a distance between the rotation axes of the first dispersion roll and the second dispersion roll.

10. A method for producing a sheet molding compound, comprising: (i) dispersing short fiber bundles using a dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, while dropping the bundles onto a carrier film traveling with its surface approximately horizontal to deposit a fiber mat; and (ii) impregnating the fiber mat with a thermosetting resin composition, wherein in the dispersion roller device, the first side cover and the second side cover are disposed between the two bearings, and the dispersion roll has a roll body having n-fold rotational symmetry (where n is an integer of 1 or more and is finite) about a rotation axis, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, and an inner peripheral surface of a circular opening provided in the first side cover faces a cylindrical peripheral surface of the first roll body adjacent portion, and an inner peripheral surface of a circular opening provided in the second side cover faces a cylindrical peripheral surface of the second roll body adjacent portion.

11. The manufacturing method according to claim 10, wherein a radius of the cylindrical circumferential surface of the first roll body adjacent portion and a radius of the cylindrical circumferential surface of the second roll body adjacent portion are equal to or greater than a maximum radius of the roll body.

12. The manufacturing method according to claim 10 or 11, wherein the roll body is a cage roll type and has a plurality of rods or wires stretched between a support member included in the first roll body adjacent portion and a support member included in the second roll body adjacent portion.

13. The manufacturing method according to any one of claims 1 to 12, wherein a material of an inner circumferential surface of the circular opening provided in each of the first side cover and the second side cover is a resin, and a material of each of the cylindrical circumferential surfaces of the first roll body adjacent portion and the second roll body adjacent portion is a metal.

14. The manufacturing method according to any one of claims 1 to 12, wherein a material of an inner circumferential surface of the circular opening provided in each of the first side cover and the second side cover is a metal, and a material of each of the cylindrical circumferential surfaces of the first roll body adjacent portion and the second roll body adjacent portion is a resin.

15. The method according to claim 13 or 14, wherein the resin is any one selected from the group consisting of tetrafluoroethylene resin, polyacetal, nylon, polyethylene, phenolic resin, polyimide, polyphenylene sulfide, polyether ether ketone, and polyamide imide.

16. The manufacturing method according to any one of claims 1 to 15, wherein a gap between an inner circumferential surface of the circular opening provided in the first side cover and the cylindrical circumferential surface of the first roll body adjacent portion, and a gap between an inner circumferential surface of the circular opening provided in the second side cover and the cylindrical circumferential surface of the second roll body adjacent portion are each 10 mm or less, 5 mm or less, 3 mm or less, 1 mm or less, or 0.5 mm or less.

17. The method according to any one of claims 1 to 16, wherein the dispersion roller device satisfies at least one of the following conditions (A) and (B): (A) The first side cover comprises a first cover body and a first ring fixed to the first cover body, and a hole in the first ring corresponds to the circular opening provided in the first side cover. (B) The second side cover comprises a second cover body and a second ring fixed to the second cover body, and a hole in the second ring corresponds to the circular opening provided in the second side cover.

18. 18. The manufacturing method according to claim 17, further comprising preparing the dispersion roller device, wherein when preparing the dispersion roller device, when the dispersion roller device satisfies the condition (A), the first roll body adjacent portion is inserted into the hole of the first ring and then the first ring is fixed to the first cover body, and when the dispersion roller device satisfies the condition (B), the second roll body adjacent portion is inserted into the hole of the second ring and then the second ring is fixed to the second cover body.

19. When the dispersion roller device satisfies the condition (A), the position of the first ring when fixed to the first cover body is variable in a plane perpendicular to the rotation axis of the dispersion roll, and when the dispersion roller device satisfies the condition (B), the position of the second ring when fixed to the second cover body is variable in a plane perpendicular to the rotation axis of the dispersion roll. The manufacturing method described in claim 17 or 18.

20. The manufacturing method according to any one of claims 1 to 19, wherein the vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the first side cover, the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the first side cover, the vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the second side cover, and the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the second side cover are greater than the maximum radius of the roll body.

21. The manufacturing method according to any one of claims 1 to 20, wherein a pair of regulator plates are disposed between the first side cover and the second side cover in parallel with the running direction of the carrier film, and the roll body of the dispersion roll is passed through both an opening of one of the pair of regulator plates and an opening of the other of the pair of regulator plates.

22. The manufacturing method according to claim 21 , wherein the openings in one of the pair of regulator plates and the openings in the other of the pair of regulator plates are both circular and have a radius larger than the maximum radius of the roll body.

23. The method according to any one of claims 1 to 22, wherein the short fiber bundles are made of carbon fibers.

24. A dispersion roller device used for dispersing short fiber bundles to be dropped onto a carrier film in the production of a sheet molding compound, the dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, wherein the first side cover and the second side cover are disposed between the two bearings, the dispersion roll has a roll body having a cylinder and a plurality of pins disposed on a circumferential surface of the cylinder, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, an inner peripheral surface of a circular opening provided in the first side cover faces a cylindrical peripheral surface of the first roll body adjacent portion, and an inner peripheral surface of a circular opening provided in the second side cover faces a cylindrical peripheral surface of the second roll body adjacent portion.

25. 25. The apparatus of claim 24, wherein a diameter of the cylindrical peripheral surface of the first roll body abutting portion and a diameter of the cylindrical peripheral surface of the second roll body abutting portion are equal to a diameter of the cylinder.

26. 25. The apparatus according to claim 24, wherein a diameter of the cylindrical circumferential surface of the first roll body abutting portion and a diameter of the cylindrical circumferential surface of the second roll body abutting portion are greater than a diameter of the cylinder.

27. 27. Apparatus according to any one of claims 24 to 26, wherein the diameter of the cylinder is between 30mm and 300mm.

28. The dispersion roll has a shaft axially penetrating the roll body, the first roll body adjacent portion, and the second roll body adjacent portion, and the diameter of the shaft is smaller than the diameter of the cylinder. The apparatus according to any one of claims 24 to 27.

29. The device according to any one of claims 24 to 28, wherein a gap between an inner circumferential surface of the circular opening provided in the first side cover and the cylindrical circumferential surface of the first roll body adjacent portion, and a gap between an inner circumferential surface of the circular opening provided in the second side cover and the cylindrical circumferential surface of the second roll body adjacent portion are both smaller than a length of the longest pin among the plurality of pins.

30. The apparatus according to any one of claims 24 to 29, wherein the dispersion roller device has, as the dispersion rolls, a first dispersion roll and a second dispersion roll arranged so that their rotation axes are parallel to each other.

31. The first dispersion roll is rotationally driven so that the pins on the roll body on the side facing the second dispersion roll move from top to bottom, and the second dispersion roll is rotationally driven so that the pins on the roll body on the side facing the first dispersion roll move from top to bottom.

32. The apparatus according to claim 30 or 31, wherein the sum of the maximum radius of the roll body of the first dispersion roll and the maximum radius of the roll body of the second dispersion roll is greater than the distance between the rotation axes of the first dispersion roll and the second dispersion roll.

33. A dispersion roller device used for dispersing short fiber bundles to be dropped onto a carrier film in the production of a sheet molding compound, the dispersion roller device having a rotationally driven dispersion roll, two bearings supporting the dispersion roll, a first side cover, and a second side cover, wherein the first side cover and the second side cover are disposed between the two bearings, and the dispersion roll has a roll body having n-fold rotational symmetry (n is an integer of 1 or more and is finite) around a rotation axis, and a first roll body adjacent portion and a second roll body adjacent portion adjacent to one end and the other end in the axial direction of the roll body, respectively, and an inner peripheral surface of a circular opening provided in the first side cover faces a cylindrical peripheral surface of the first roll body adjacent portion, and an inner peripheral surface of a circular opening provided in the second side cover faces a cylindrical peripheral surface of the second roll body adjacent portion.

34. The apparatus of claim 33, wherein a radius of the cylindrical circumferential surface of the first roll body adjacent portion and a radius of the cylindrical circumferential surface of the second roll body adjacent portion are equal to or greater than a maximum radius of the roll body.

35. The apparatus according to claim 33 or 34, wherein the roll body is a cage roll type and has a plurality of rods or wires stretched between a support member included in the first roll body adjacent portion and a support member included in the second roll body adjacent portion.

36. The device according to any one of claims 24 to 35, wherein a material of an inner circumferential surface of the circular opening provided in each of the first side cover and the second side cover is a resin, and a material of each of the cylindrical circumferential surfaces of the first roll body adjacent portion and the second roll body adjacent portion is a metal.

37. The device according to any one of claims 24 to 35, wherein a material of an inner peripheral surface of the circular opening provided in each of the first side cover and the second side cover is metal, and a material of each of the cylindrical peripheral surfaces of the first roll body adjacent portion and the second roll body adjacent portion is resin.

38. 38. The device according to claim 36 or 37, wherein the resin comprises any one selected from the group consisting of tetrafluoroethylene resin, polyacetal, nylon, polyethylene, phenolic resin, polyimide, polyphenylene sulfide, polyether ether ketone, and polyamide imide.

39. The device according to any one of claims 24 to 38, wherein a gap between an inner peripheral surface of the circular opening provided in the first side cover and the cylindrical peripheral surface of the first roll body adjacent portion, and a gap between an inner peripheral surface of the circular opening provided in the second side cover and the cylindrical peripheral surface of the second roll body adjacent portion are each 10 mm or less, 5 mm or less, 3 mm or less, 1 mm or less, or 0.5 mm or less.

40. The device according to any one of claims 24 to 39, which satisfies at least one of the following conditions (A) and (B): (A) The first side cover comprises a first cover body and a first ring fixed to the first cover body, and a hole in the first ring corresponds to the circular opening provided in the first side cover. (B) The second side cover comprises a second cover body and a second ring fixed to the second cover body, and a hole in the second ring corresponds to the circular opening provided in the second side cover.

41. The device described in claim 40, wherein, when condition (A) is satisfied, the position of the first ring when fixed to the first cover body is variable in a plane perpendicular to the rotation axis of the dispersion roll, and, when condition (B) is satisfied, the position of the second ring when fixed to the second cover body is variable in a plane perpendicular to the rotation axis of the dispersion roll.

42. The vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the first side cover, the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the first side cover, the vertical distance from the rotation axis of the dispersion roll to each of the upper and lower edges of the second side cover, and the horizontal distance from the rotation axis of the dispersion roll to each of the leading and trailing edges of the second side cover are greater than the maximum radius of the roll body.

43. The apparatus according to any one of claims 24 to 42, wherein a pair of regulator plates are disposed between the first side cover and the second side cover in parallel with the running direction of the carrier film, and the roll body of the dispersion roll is passed through both an opening in one of the pair of regulator plates and an opening in the other of the pair of regulator plates.

44. 44. The apparatus of claim 43, wherein the openings in one and the other of the pair of regulator plates are both circular and have a radius greater than the maximum radius of the roll body.

45. Use of an apparatus according to any one of claims 24 to 44 in a sheet moulding compound manufacturing apparatus.

46. 46. ​​The use according to claim 45, wherein the sheet molding compound manufacturing equipment comprises two coaters, a laminator and an impregnator.

47. 47. The use of claim 46, wherein the sheet molding compound manufacturing apparatus further comprises a chopper.

48. An apparatus for producing a sheet moulding compound, comprising an apparatus according to any one of claims 24 to 44.

49. 49. The sheet molding compound manufacturing apparatus of claim 48, further comprising two coaters, a laminator, and an impregnator.

50. 50. The apparatus of claim 49, further comprising a chopper.

51. A method for producing a sheet molding compound, using the sheet molding compound production apparatus according to any one of claims 48 to 50.

52. The method of claim 51, which is a method for producing a CF-SMC.

Images