JP2018126975A - Method for manufacturing sheet molding compound and apparatus for manufacturing sheet molding compound - Google Patents

Abstract

A method for producing SMC, in which when two or more types of fiber bundles having different fiber types and fiber weights are used, an SMC in which fiber bundles after cutting are uniformly dispersed and physical property variations are suppressed, and An object of the present invention is to provide an SMC manufacturing apparatus. SOLUTION: Using an SMC manufacturing apparatus 1, two or more types of long fiber bundles f1 having different one or both of fiber type and fiber basis weight are cut by a roving cutter 12, and the cut fiber bundle f2, After slipping down the inclined surface 14 a of the inclined member 14, it falls on the first carrier film C <b> 1 running in one direction to form the sheet-like fiber bundle group F, and the resin is applied to the sheet-like fiber bundle group F. A method for producing a sheet molding compound, wherein the composition P is impregnated. [Selection] Figure 1

Description

  The present invention relates to a method for manufacturing a sheet molding compound and an apparatus for manufacturing a sheet molding compound.

  A sheet molding compound (hereinafter also referred to as “SMC”) uses a sheet-like fiber bundle group in which short fiber bundles having a fiber length of about 25 mm are dispersed in a random direction as a reinforcing material. Therefore, SMC has a lower mechanical property of the composite material obtained by molding than a prepreg using a reinforcing material in which continuous long fiber bundles are aligned. On the other hand, the material constituting SMC is easy to flow in the mold at the time of molding, and it is easy to fill the fine space part, so a complicated shape with fine unevenness that is difficult to mold with prepreg using continuous long fiber bundle It is suitable for forming a composite material.

  Glass fibers and carbon fibers are known as reinforcing fibers used for fiber bundles. If glass fiber is used, excellent moldability is easily obtained, which is advantageous in terms of cost. Since carbon fiber has high specific strength and specific elastic modulus, the resulting composite material has high rigidity, and the composite material can be significantly reduced in weight. Moreover, since carbon fiber is excellent in the fluidity | liquidity at the time of shaping | molding, the freedom degree of shaping is high.

  SMC using carbon fiber has a great merit in terms of weight reduction and is considered disadvantageous in terms of cost, although it is considered to be used in the field of industrial members such as automobiles. Then, SMC which uses together a carbon fiber and glass fiber is proposed for the purpose of making weight reduction and low cost compatible (patent documents 1).

  As a manufacturing method of SMC, continuous long fiber bundles are cut with a roving cutter, the cut fiber bundles are separated into sheets, and the formed sheet-like fiber bundle group is impregnated with a resin composition, and SMC is produced. (Patent Documents 1 and 2).

JP 2014-19707 A JP 2010-163536 A

  However, in methods such as Patent Documents 1 and 2, when using two or more types of fiber bundles having different fiber types, such as a carbon fiber bundle and a glass fiber bundle, particularly in the thickness direction of the sheet-like fiber bundle group, The fiber bundle cut by the roving cutter tends to be non-uniform, and the physical properties may vary. Also, when two or more types of fiber bundles having different fiber weights are used, similarly, the fiber bundle after cutting is likely to be non-uniform in the sheet-like fiber bundle group, and physical properties may vary.

  The present invention provides an SMC manufacturing method in which when two or more types of fiber bundles having different fiber types and fiber weights are used, an SMC in which fiber bundles after cutting are uniformly dispersed and physical property variation is suppressed is obtained. And it aims at providing the manufacturing apparatus of SMC.

The present invention has the following configuration.
[1] Two or more types of long fiber bundles with different one or both of fiber type and fiber basis weight are cut with a roving cutter, and the cut fiber bundle is dropped on a carrier film traveling in one direction. Forming a sheet-like fiber bundle group and impregnating the sheet-like fiber bundle group with a resin composition,
An inclined member having an inclined surface inclined with respect to the horizontal direction is disposed between the roving cutter and the carrier film,
A method for producing an SMC, wherein the sheet-like fiber bundle group is formed after the cut fiber bundle slides down the inclined surface.
[2] The SMC manufacturing method according to [1], wherein at least one of the two or more types of fiber bundles is a carbon fiber bundle.
[3] The SMC manufacturing method according to [1] or [2], wherein the two or more types of fiber bundles include a carbon fiber bundle and a glass fiber bundle.
[4] A carrier film transport unit that transports the carrier film;
A roving cutter that is provided above a carrier film that runs in one direction and cuts a long fiber bundle into a predetermined length;
A fiber bundle supply unit that supplies two or more types of long fiber bundles with different one or both of fiber type and fiber basis weight to the roving cutter;
An inclined member disposed between the roving cutter and the carrier film and having an inclined surface inclined with respect to a horizontal direction;
An impregnation part for impregnating a resin composition into a sheet-like fiber bundle group formed on the carrier film by a fiber bundle cut by the roving cutter,
An apparatus for manufacturing a sheet molding compound, in which a fiber bundle cut by the roving cutter slides down on the inclined surface and then falls onto a carrier film to form the sheet-like fiber bundle group.

According to the SMC manufacturing method of the present invention, when two or more types of fiber bundles having different fiber types and fiber weights are used, the SMC in which the fiber bundles after cutting are uniformly dispersed and the variation in physical properties is suppressed is obtained. Can be manufactured.
Using the SMC manufacturing apparatus of the present invention, when two or more types of fiber bundles having different fiber types and fiber weights are used, the SMC in which the fiber bundles after cutting are uniformly dispersed and the variation in physical properties is suppressed. Can be manufactured.

It is the schematic block diagram which showed an example of the manufacturing apparatus of SMC of this invention. It is the schematic block diagram which expanded and showed the part of the roving cutter of the manufacturing apparatus of SMC of FIG.

[SMC manufacturing equipment]
The SMC production apparatus of the present invention is an apparatus for producing SMC in which a sheet-like fiber bundle group formed from a plurality of fiber bundles cut into a predetermined length is impregnated with a resin composition.
The SMC manufacturing apparatus of the present invention includes a carrier film transport unit, a roving cutter, a fiber bundle supply unit, an inclined member, and an impregnation unit. A carrier film conveyance part is a part which conveys a carrier film. The roving cutter is a portion that is provided above a carrier film that runs in one direction and cuts a long fiber bundle into a predetermined length. The fiber bundle supply unit is a part that supplies two or more types of long fiber bundles having different one or both of the fiber type and the fiber basis weight to the roving cutter. The inclined member is disposed between the roving cutter and the carrier film and has an inclined surface inclined with respect to the horizontal direction. An impregnation part is a part which impregnates a resin composition in the sheet-like fiber bundle group formed on the carrier film with the fiber bundle cut | disconnected with the roving cutter.
In the SMC manufacturing apparatus of the present invention, the fiber bundle cut by the roving cutter slides down the inclined surface of the inclined member and then falls onto the carrier film, thereby forming a sheet-like fiber bundle group.

  Hereinafter, an example of an SMC manufacturing apparatus according to the present invention will be described. FIG. 1 is a schematic configuration diagram illustrating a sheet molding compound manufacturing apparatus 1 (hereinafter referred to as “SMC manufacturing apparatus 1”) according to the present embodiment. In the following description, an XYZ rectangular coordinate system is set, and the positional relationship of each member will be described with reference to the XYZ rectangular coordinate system as necessary. Note that the materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not necessarily limited thereto, and can be implemented with appropriate modifications within a range that does not change the gist thereof. .

  The SMC manufacturing apparatus 1 includes a fiber bundle supply unit 10, a roving cutter 12, an inclined member 14, a first unwinder 16, a carrier film transport unit 18, a first coating unit 20, and a second unwinding unit. A machine 22, a second coating unit 24, an impregnation unit 26, and a winder 28 are provided.

  The fiber bundle supply unit 10 is a part that supplies the roving cutter 12 with two or more types of continuous long fiber bundles f1 that are different in either or both of the fiber type and the fiber basis weight. In the fiber bundle supply unit 10 of this example, a plurality of original fabric rolls R in which two or more types of fiber bundles f1 are wound around each bobbin are held in a rotatable manner by creels.

  The first unwinding machine 16 is provided with a first raw roll R1 around which a long first carrier film C1 is wound. The first unwinding machine 16 unwinds the long first carrier film C <b> 1 from the first raw roll R <b> 1 and supplies it to the carrier film transport unit 18. The carrier film transport unit 18 includes a conveyor 19 in which an endless belt 19c is hung between a pair of pulleys 19a and 19b. The conveyor 19 rotates the endless belt 19c by rotating the pair of pulleys 19a and 19b in the same direction, and conveys the first carrier film C1 toward the right side in the X-axis direction on the surface of the endless belt 19c. As the endless belt 19c, for example, a mesh belt can be used.

  The first coating unit 20 is located immediately above the pulley 19 a side in the carrier film transport unit 18, and includes a doctor blade 21 that coats the resin composition P. By passing the first carrier film C1 through the first coating part 20, the resin composition P is applied with a predetermined thickness on the surface of the first carrier film C1 by the doctor blade 21, and the first resin sheet S1 is formed. It is formed. The first resin sheet S1 travels along with the conveyance of the first carrier film C1.

The roving cutter 12 cuts the plurality of fiber bundles f1 supplied from the fiber bundle supply unit 10 into a predetermined fiber length. The roving cutter 12 is provided above the first carrier film C1.
The roving cutter 12 of this example includes a rubber roller 30 and a cutter roller 32 as shown in FIG. In the cutter roller 32, a plurality of blades 36 extending in the axial direction of the roll part 34 are provided on the peripheral surface 34 a of the cylindrical roll part 34 at intervals in the circumferential direction of the roll part 34. The distance between the blades 36 in the circumferential direction of the roving cutter 12 is adjusted to a desired cut length.

  In the roving cutter 12, the rubber roller 30 and the cutter roller 32 rotate in opposite directions while the fiber bundle f1 is sandwiched between the rubber roller 30 and the cutter roller 32. Thereby, the fiber bundle f1 unwound from the original fabric roll R is cut | disconnected intermittently, and it is set as the fiber bundle f2 of desired length.

The inclined member 14 is a member having an inclined surface 14a inclined upward with respect to the horizontal direction. The inclined member 14 of this example is a plate-like member, and is provided between the roving cutter 12 and the first carrier film C1 so that the inclined surface 14a is inclined with respect to the horizontal direction. The fiber bundle f2 cut by the roving cutter 12 falls on the inclined surface 14a of the inclined member 14, slides down on the inclined surface 14a, and then on the first resin sheet S1 formed on the first carrier film C1. Sprayed on. Thereby, a sheet-like fiber bundle group F in which two or more types of fiber bundles f2 are uniformly dispersed is formed.
The shape of the inclined member 14 is not limited to a plate shape as long as it has the inclined surface 14a, and may be, for example, a triangular prism shape.

  The length from the upper edge to the lower edge of the inclined surface 14a of the inclined member 14 is preferably 5 cm to 50 cm, and more preferably 10 cm to 30 cm. If the length of the inclined surface 14a is equal to or greater than the lower limit of the above range, it is easy to suppress the cut fiber bundle f2 from falling without contacting the inclined surface 14a, and two or more types of fiber bundles f2. Is easily formed. If the length of the inclined surface 14a is less than or equal to the upper limit of the above range, the fiber bundle f2 stops while sliding down on the inclined surface 14a, and the fiber bundle f2 is easily prevented from accumulating on the inclined surface 14a.

  The inclination angle θ (FIG. 2) of the inclined surface 14a of the inclined member 14 with respect to the horizontal direction is preferably 30 ° or more and 90 ° or less, and more preferably 45 ° or more and 80 ° or less. If the inclination angle θ of the inclined surface 14a is equal to or greater than the lower limit of the above range, the fiber bundle f2 stops while sliding down on the inclined surface 14a, and it is easy to suppress the fiber bundle f2 from accumulating on the inclined surface 14a. If the inclination angle θ of the inclined surface 14a is less than or equal to the upper limit of the above range, two or more types of fiber bundles f2 are likely to be uniformly dispersed.

The installation position of the inclined member 14 is preferably as close as possible to the contact point between the rubber roller 30 and the cutter roller 32 within the range where the inclined member 14 does not contact the roving cutter 12 below the roving cutter 12. As the position of the inclined member 14 is closer to the roving cutter 12, it is easier to suppress the cut fiber bundle f2 from falling without hitting the inclined surface 14a of the inclined member 14.
The distance between the lowest point of the rubber roller 30 and the upper end of the inclined member 14 is preferably 10 to 300 mm, and more preferably 30 to 150 mm.

  In addition, the installation position of the inclined member 14 is not limited to the above preferable range, it is confirmed at what angle the cut fiber bundle f2 falls, and all the fiber bundles f2 are inclined surfaces of the inclined member 14. 14a can be adjusted so that it can fall while sliding.

  The material forming the inclined member 14 may be any material as long as the fiber bundle can slide down, and examples thereof include metal, plastic, rubber, wood, cardboard, and glass. As a material for forming the inclined member 14, one type may be used alone, or two or more types may be used in combination.

Examples of the metal include aluminum, stainless steel, iron, copper and the like, and aluminum or stainless steel is preferable from the viewpoint of excellent handleability.
Examples of the plastic include polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), acrylic, nylon, polycarbonate, Teflon (registered trademark), and polystyrene foam.
Among these, polyethylene and polypropylene are preferable from the viewpoint of easy weight reduction, and polycarbonate is more preferable from the viewpoint of excellent visibility.

  The second unwinding machine 22 is provided with a second raw roll R2 around which a long second carrier film C2 is wound. The second unwinding machine 22 unwinds the long second carrier film C2 from the second raw fabric roll R2 and supplies it to the subsequent stage of the roving cutter 12 on the carrier film transport unit 18 by a plurality of guide rolls 23. . The second carrier film C2 unwound from the second unwinder 22 is transported in the direction opposite to the transport direction of the first carrier film C1 (left side in the X-axis direction), and then the transport direction is a plurality of guide rolls. 23 is reversed in the same direction as the first carrier film C1.

  The second coating part 24 includes a doctor blade 25 that is positioned immediately above the second carrier film C2 that is transported in the direction opposite to the transport direction of the first carrier film C1 and that coats the resin composition P. . By passing the second carrier film C2 through the second coating part 24, the resin composition P is coated on the surface of the second carrier film C2 with a predetermined thickness by the doctor blade 25, and the second resin sheet S2 is formed. It is formed. The second resin sheet S2 travels along with the conveyance of the second carrier film C2.

  The impregnation part 26 is a part in which the second resin sheet S2 is bonded onto the sheet-like fiber bundle group F and pressed, and the resin composition P is impregnated into the sheet-like fiber bundle group F to form SMC. The impregnation unit 26 is located at a later stage than the roving cutter 12 in the carrier film transport unit 18. The impregnation unit 26 includes a plurality of pressure rolls 27. The plurality of pressure rolls 27 are arranged so as to contact the back surface of the second carrier film C2 reversed in the same direction as the first carrier film C1, that is, the surface opposite to the second resin sheet S2.

  In the impregnation portion 26, the first carrier film C1 and the second carrier film C2 are overlapped with the first resin sheet S1, the sheet-like fiber bundle group F, and the second resin sheet S2 being sandwiched therebetween, and a plurality of additional films are added. It is conveyed while being pressurized by the pressure roll 27. As a result, the resin composition of the first resin sheet S1 and the second resin sheet S2 is impregnated into the sheet-like fiber bundle group F, and an SMC raw fabric R3 is obtained.

  The original fabric R3 is wound around a winder 28. The original fabric R3 can be cut into a predetermined length and used for molding. In addition, the 1st carrier film C1 and the 2nd carrier film C2 are peeled from SMC before shaping | molding.

The SMC manufacturing apparatus of the present invention is not limited to the SMC manufacturing apparatus 1 described above.
For example, in the SMC manufacturing apparatus 1, two or more types of fiber bundles f1 are each wound on a bobbin to form an original roll. However, two or more types of fiber bundles are wound on a single bobbin without converging each other. A device that unwinds each fiber bundle from the raw fabric roll and cuts it with a roving cutter may be used. Also in this case, each fiber bundle is easily separated by cutting, and the fiber bundle is smoothly and intermittently cut to a predetermined length.
In addition, the SMC manufacturing apparatus of the present invention may be an apparatus that does not include a coating unit that coats the resin composition on the lower first carrier film.

[Manufacturing method of SMC]
In the SMC manufacturing method of the present invention, two or more types of long fiber bundles having different one or both of the fiber type and fiber basis weight are cut with a roving cutter, and the cut fiber bundle is run in one direction. This is a method in which a sheet-like fiber bundle group is formed by dropping on a carrier film and the sheet-like fiber bundle group is impregnated with a resin composition to obtain SMC. In the present invention, an inclined member having an inclined surface inclined with respect to the horizontal direction is disposed between the roving cutter and the carrier film, and a sheet-like fiber bundle group is formed after the cut fiber bundle slides down the inclined surface. To be.

Hereinafter, an SMC manufacturing method using the SMC manufacturing apparatus 1 will be described as an example of the SMC manufacturing method of the present invention.
In the manufacturing method of the present embodiment, the first unwinding machine 16 unwinds the long first carrier film C <b> 1 from the first raw roll R <b> 1 and supplies it to the carrier film transport unit 18. And the 1st resin sheet S1 is formed by apply | coating the resin composition P with the predetermined | prescribed thickness by the 1st coating part 20 on the surface of the 1st carrier film C1. By transporting the first carrier film C1 by the carrier film transport unit 18, the first resin sheet S1 on the first carrier film C1 is caused to travel.

  Further, the fiber bundle supply unit 10 supplies two or more types of continuous long fiber bundles f <b> 1 to the roving cutter 12. When supplying to the roving cutter 12, it is preferable to supply two or more types of fiber bundles f1 so as to be arranged at equal intervals in the axial direction (Y-axis direction) of the roving cutter 12. Thereby, it becomes easy to disperse each fiber bundle uniformly in the width direction of the SMC, and it becomes easy to suppress the occurrence of variations in physical properties.

  Two or more types of fiber bundles f 1 supplied from the fiber bundle supply unit 10 are cut by the roving cutter 12. The cut fiber bundle f2 falls on the inclined surface 14a of the inclined member 14, slides down on the inclined surface 14a, and falls on the first resin sheet S1 formed on the first carrier film C1. Thereby, the sheet-like fiber bundle group F which consists of several fiber bundle f2 is formed on 1st resin sheet S1. By allowing the cut fiber bundle f2 to slide down on the inclined surface 14a of the inclined member 14, two or more types of fiber bundles f2 are uniformly dispersed in the sheet-like fiber bundle group F even in the thickness direction.

  2-100 mm is preferable, as for the length of the fiber bundle f2 after a cutting | disconnection, 5-50 mm is more preferable, and 10-30 mm is further more preferable. When the length of the fiber bundle f2 is not less than the lower limit of the above range, excellent rigidity is easily obtained, and the weight of the composite material can be easily reduced. If the length of the fiber bundle f2 is equal to or less than the upper limit of the above range, the flowability of SMC becomes better during molding, and it becomes easier to produce a complex shaped composite material.

  The second unwinding machine 22 unwinds the long second carrier film C2 from the second raw fabric roll R2, and the second coating unit 24 deposits the resin composition P on the surface of the second carrier film C2 with a predetermined thickness. To form a second resin sheet S2. The second resin sheet S2 is caused to travel by conveying the second carrier film C2, the second resin sheet S2 is bonded onto the sheet-like fiber bundle group F, and the impregnation unit 26 pressurizes the plurality of pressure rolls 27. The sheet-like fiber bundle group F is impregnated with the resin composition P of the first resin sheet S1 and the second resin sheet S2. Thereby, the raw fabric R3 in which the SMC is sandwiched between the first carrier film C1 and the second carrier film C2 is obtained. The original fabric R3 is wound around the winder 28.

As the fiber bundle f1, two or more types of long fiber bundles having different one or both of the fiber type and the fiber basis weight are used. As the fiber bundle f1, two or more types of fiber bundles having the same fiber basis weight and different fiber types may be used, or two or more types of fiber bundles having the same fiber type and different fiber basis weights may be used. Two or more types of fiber bundles having different fiber types and fiber basis weights may be used. In any of these embodiments, two or more types of fiber bundles after cutting can be uniformly dispersed in the sheet-like fiber bundle group.
The number of fiber bundles f1 is preferably 10 or more and 200 or less, more preferably 30 or more and 150 or less, although it depends on the width of the SMC to be produced and the fiber basis weight.

  Examples of the type of fiber used for the fiber bundle f1 include glass fiber, carbon fiber, metal fiber, and organic fiber. In terms of weight reduction, specific strength, and rigidity improvement, it is preferable that at least one of the two or more types of fiber bundles f1 is a carbon fiber bundle. Further, in addition to weight reduction, specific strength, and rigidity, from the viewpoint of cost, the two or more types of fiber bundles f1 preferably include a carbon fiber bundle and a glass fiber bundle.

The fiber basis weight of the fiber bundle f1 is preferably 0.1 g / m or more and 10 g / m or less.
When using a carbon fiber bundle, the fiber basis weight of the carbon fiber bundle is preferably 0.1 g / m or more and 5 g / m or less. When a glass fiber bundle is used, the fiber basis weight of the glass fiber bundle is preferably 0.5 g / m or more and 10 g / m or less. In the case of using two or more types of fiber bundles having different fiber weights, uniform dispersion is particularly difficult with the conventional method when the difference in the fiber weights of these fiber bundles is 0.3 g / m or more. The method is particularly useful.

  Even when two or more types of fiber bundles having different thicknesses are used, the fiber bundles tend to be non-uniformly distributed in the sheet-like fiber bundle group. It can be uniformly dispersed. In addition, the thickness of a fiber bundle means the thickness of the part which contacted the fiber bundle first when measuring with a micrometer. When the fiber bundle is flat, the thickness is in the short side direction. The production method of the present invention is particularly useful when the difference in thickness between fiber bundles having different thicknesses is 100 μm or more.

  As the resin composition, a resin composition containing a thermosetting resin is preferable. Examples of the thermosetting resin include an epoxy resin, a vinyl ester resin, an unsaturated polyester resin, a polyimide resin, a maleimide resin, and a phenol resin. When carbon fiber is used as the reinforcing fiber, the thermosetting resin is preferably an epoxy resin or a vinyl ester resin from the viewpoint of adhesion to the carbon fiber. As a thermosetting resin, 1 type may be used independently and 2 or more types may be used together.

The resin composition preferably contains a polymerizable monomer in addition to the thermosetting resin.
The combination of the kind of polymerizable monomer and the kind of thermosetting resin is not particularly limited as long as a polymerizable monomer suitable for the thermosetting resin to be used is used. For example, in the case of a vinyl ester resin or an unsaturated polyester resin, a polymerizable monomer such as a styrene monomer, an acrylic monomer, a methacrylic monomer, or a mixed system thereof is preferable. In the case of an epoxy resin, a monomer containing an epoxy group is preferred. As a polymerizable monomer, 1 type may be used independently and 2 or more types may be used together.

  The resin composition may contain additives such as a thickener, an inorganic filler, a curing agent, a polymerization initiator, a polymerization inhibitor, a pigment, and an internal release agent. As an additive, 1 type may be used independently and 2 or more types may be used together.

  As the thickener, known materials suitable for thermosetting resins can be used, for example, metal oxides such as magnesium oxide and calcium oxide; isocyanates such as diphenylmethane diisocyanate (MDI) and modified products of MDI; An acid excess etc. are mentioned.

  Examples of inorganic fillers include calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, silica, fused silica, barium sulfate, titanium oxide, magnesium oxide, calcium oxide, aluminum oxide, calcium phosphate, talc, Examples include mica, clay, and glass powder. The content of the inorganic filler is preferably the minimum necessary in terms of weight reduction, and may be 0%.

As a hardening | curing agent, the well-known thing suitable for the resin composition to be used can be used. For example, when a vinyl ester resin or an unsaturated polyester resin is used, a general organic peroxide is preferable. In the case of an epoxy resin, an amine-based or acid anhydride-based curing agent is preferable.
Examples of the internal mold release agent include fatty acid metal salts such as zinc stearate and surfactants such as sodium dialkylsulfosuccinate.

  The resin composition P may be a resin composition containing a thermoplastic resin.

The content of the resin composition in SMC is preferably 30 to 70% by mass with respect to the total mass of SMC. If the content of the resin composition is 30% by mass or more, the resin composition is favorably impregnated into the sheet-like fiber bundle group, and excellent physical properties are easily obtained. If content of a resin composition is 70 mass% or less, it exists in the tendency for the mechanical strength of the composite material after shaping | molding to become favorable.
The lower limit of the content of the resin composition in SMC is more preferably 35% by mass, and particularly preferably 40% by mass. The upper limit of the content of the resin composition in SMC is more preferably 65% by mass, and particularly preferably 60% by mass.

By causing the cut fiber bundle f2 to slide down on the inclined surface 14a of the inclined member 14, the factor that the two or more types of fiber bundles f2 are evenly dispersed in the thickness direction of the sheet-like fiber bundle group F is as follows: Not necessarily obvious.
In the conventional method, when two or more types of fiber bundles having different fiber types and fiber weights are cut with a roving cutter, the fiber bundles can be cut depending on the fiber types and fiber weights even when cutting each fiber bundle with the same blade. It is considered that the timing at which the fiber is completely cut is different, or the fiber bundle may be bent when the blade contacts. As a result, the fiber bundles are easily deposited in layers on the carrier film in a layered manner because the timing, angle and speed at which the cut fiber bundles fall differ depending on the type and basis weight of the fibers. Dispersion will be difficult.

  On the other hand, in the method using the SMC manufacturing apparatus 1, the fiber bundle f2 cut by the roving cutter 12 once drops and slides down on the inclined surface 14a, and drops from the inclined surface 14a onto the first resin sheet S1. . This reduces the effects of differences in the timing at which the cut fiber bundles fall due to differences in fiber types and fiber basis weights, as well as the differences in the angle and speed of dropping. It is thought that it is uniformly dispersed.

  As described above, in the present invention, two or more types of long fiber bundles having different fiber types and fiber weights are cut with a roving cutter, and the cut fiber bundle is disposed below the roving cutter. The inclined surface of the member is slid down and dropped onto the carrier film so that a sheet-like fiber bundle group is formed. Thereby, two or more types of fiber bundles are uniformly dispersed, and an SMC in which variations in physical properties are suppressed is obtained.

Note that the SMC manufacturing method of the present invention is not limited to the method using the SMC manufacturing apparatus 1 described above. For example, in the SMC manufacturing apparatus 1, two or more types of fiber bundles f1 are each wound on a bobbin to form an original roll. However, two or more types of fiber bundles are wound on a single bobbin without converging each other. Each fiber bundle may be unwound from the raw fabric roll and cut with a roving cutter.
Further, the SMC manufacturing method of the present invention may be a method in which the first resin sheet is not formed on the lower first carrier film, but the sheet-like fiber bundle group is directly formed on the first carrier film. .

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by the following description.
[Dispersibility evaluation of fiber bundles]
In the sheet-like fiber bundle group formed in each example, a fiber bundle in an upper layer region having a thickness of 5 mm × length of 10 cm × 10 cm was collected from the upper surface, and the glass fiber bundle and the carbon fiber bundle were separated and their masses were measured. Moreover, the fiber bundle of the lower layer area | region of thickness 5mm x length 10cm x 10cm in the sheet-like fiber bundle group was extract | collected, the glass fiber bundle and the carbon fiber bundle were divided | segmented, and mass was measured, respectively. The measurement was performed 3 times, and the average value was obtained.

[Example 1]
Using the SMC manufacturing apparatus 1 shown in FIGS. 1 and 2, a sheet-like fiber bundle group F was formed as shown below.
As the inclined member 14, a stainless steel plate (thickness 2 mm, width 70 cm, length 20 cm) was placed between the roving cutter 12 and the first carrier film C1. The installation position of the inclined member 14 was a position where the upper end of the inclined member 14 came to be 3 cm from the lowest point of the rubber roller 30 in the roving cutter 12. In addition, the inclination angle θ of the inclined surface 14a of the inclined member 14 with respect to the horizontal direction was 45 °.
As the fiber bundle f1, 37 carbon fiber bundles (trade name “TR50S 15L” manufactured by Mitsubishi Rayon Co., Ltd., fiber basis weight: 1.0 g / m) and glass fiber bundles (manufactured by Nittobo Co., Ltd., trade name “Glass Roving RS480PB”) -549AN ", fiber basis weight: 4.8 g / m), and 13 fibers are continuously fed to the roving cutter 12 so that the fiber bundles do not overlap at the time of cutting, and the fiber bundle f2 after cutting becomes 1 inch. Cutting was performed so that The arrangement of the fiber bundles f1 supplied to the roving cutter 12 was a repetition of three carbon fiber bundles and one glass fiber bundle in the axial direction of the roving cutter 12.
The traveling speed of the first carrier film was 5 m / min. The resin composition is not applied onto the first carrier film, and the fiber bundle f2 cut by the roving cutter 12 slides down the inclined surface 14a of the inclined member 14 and drops onto the first carrier film, so that the fiber A sheet-like fiber bundle group F having a basis weight of 1600 g / m ² was formed.

[Comparative Example 1]
A sheet-like fiber bundle group was formed in the same manner as in Example 1 except that the inclined member 14 was not installed between the roving cutter 12 and the first carrier film C1.

  Table 1 shows the measurement results of the masses of the carbon fiber bundle and glass fiber bundle in the upper layer region and the lower layer region in the sheet-like fiber bundle group of each example.

As shown in Table 1, in Example 1 in which the fiber bundle f2 cut by the roving cutter 12 slides down the inclined surface 14a of the inclined member 14, the mass of the carbon fiber bundle and the mass of the glass fiber bundle are the sheet-like fibers. The upper and lower layers of the bundle group were almost the same, and the carbon fiber bundle and the glass fiber bundle were uniformly dispersed.
On the other hand, in Comparative Example 1 in which the inclined member 14 is not provided, the fiber bundles present in the upper layer in the sheet-like fiber bundle group are substantially glass fiber bundles, and the fiber bundles present in the lower layer are substantially carbon fiber bundles. The bundle and the glass fiber bundle could not be uniformly dispersed and had two layers.

  DESCRIPTION OF SYMBOLS 1 ... Sheet molding compound manufacturing apparatus, 10 ... Fiber bundle supply part, 12 ... Roving cutter, 14 ... Inclined member, 14a ... Inclined surface, 16 ... 1st unwinding machine, 18 ... Carrier film conveyance part, 20 ... 1st Coating part 22 ... second unwinding machine 24 ... second coating part 26 ... impregnation part 28 ... winding machine 30 ... rubber roller 32 ... cutter roller 34 ... roll part 36 ... blade f1 , F2 ... fiber bundle, F ... sheet-like fiber bundle group, C1 ... first carrier film, C2 ... second carrier film, P ... resin composition, S1 ... first resin sheet, S2 ... second resin sheet.

Claims (4)

Two or more types of long fiber bundles with different one or both of fiber type and fiber basis weight are cut with a roving cutter, and the cut fiber bundles are dropped onto a carrier film running in one direction to form a sheet. A sheet molding compound manufacturing method for forming a fiber bundle group and impregnating the sheet-like fiber bundle group with a resin composition,
An inclined member having an inclined surface inclined with respect to the horizontal direction is disposed between the roving cutter and the carrier film,
A method for producing a sheet molding compound, wherein the cut fiber bundle slides down the inclined surface and then falls onto a carrier film to form the sheet-like fiber bundle group.   The method for producing a sheet molding compound according to claim 1, wherein at least one of the two or more types of fiber bundles is a carbon fiber bundle.   The method for producing a sheet molding compound according to claim 1 or 2, wherein the two or more types of fiber bundles include a carbon fiber bundle and a glass fiber bundle. A carrier film transport section for transporting the carrier film;
A roving cutter that is provided above a carrier film that runs in one direction and cuts a long fiber bundle into a predetermined length;
A fiber bundle supply unit that supplies two or more types of long fiber bundles with different one or both of fiber type and fiber basis weight to the roving cutter;
An inclined member disposed between the roving cutter and the carrier film and having an inclined surface inclined with respect to a horizontal direction;
An impregnation part for impregnating a resin composition into a sheet-like fiber bundle group formed on the carrier film by a fiber bundle cut by the roving cutter,
An apparatus for manufacturing a sheet molding compound, in which a fiber bundle cut by the roving cutter slides down on the inclined surface and then falls onto a carrier film to form the sheet-like fiber bundle group.

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