JPH0740341A - Production of fibrous composite sheet - Google Patents

Abstract

PURPOSE:To obtain a fibrous composite sheet capable of forming a molded article having a superior strength and a uniform wall thickness. CONSTITUTION:Parallel 12 glass rovings F each made of a large number of continuous monofilaments are passed through a fluid bed R of a powder vinyl chloride resin 9 while being fibrillated, thereby being impregnated with the vinyl chloride resin 9. The fibrillated resin-impregnated glass rovings are melted under heat to a sheet form. This is cooled and set to form a glass-fiber reinforced vinyl chloride sheet. At this time, parallel glass rovings F to be introduced into the fluid bed R are alternately divided into two groups. The groups are separately passed through guide bars 12A, 12B, 13A, 13B arranged in pairs on different positions in the fluid bed R for every group in pressure contact with the guide bars. After that, the glass rovings of the respective groups FA, FB are led to a common guide bar 14. The adjacent side edges of the fibrillated glass rovings are overlapped with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber composite sheet such as a fiber reinforced thermoplastic resin prepreg sheet.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a fiber composite sheet, a reinforced fiber bundle composed of a large number of continuous monofilaments is passed through a fluidized bed of a powdery thermoplastic resin, and while being opened, powdery heat is applied thereto. A method of impregnating a plastic resin, heating and melting it into a sheet (see Japanese Patent Application Laid-Open No. 46-4545), and a plurality of fibers that are tensioned in parallel and uniformly are placed in a tank filled with a powdery thermoplastic resin. A method in which a powdery thermoplastic resin is adhered to the fiber by passing it, excess resin is removed by vibrating the fiber, and then heat-melt molding is performed (see Japanese Patent Publication No. 63-67446). is there.

[0003]

In the conventional method for producing a fiber composite sheet described above, the reinforcing fiber bundle cannot be opened sufficiently and uniformly in the fluidized bed, and the reinforcing fiber bundle is uniformly coated with the powdery thermoplastic resin. Cannot be impregnated into. As a result, the molded product molded from the obtained fiber composite sheet was inferior in strength because the fiber distribution was not uniform, and the thickness was uneven. An object of the present invention is to provide a method for producing a fiber composite sheet, which is capable of obtaining a molded product having excellent strength and a uniform wall thickness.

[0004]

According to a first aspect of the present invention, there is provided a method for producing a fiber composite sheet in a fluidized bed of a powdery thermoplastic resin while opening parallel reinforcing fiber bundles composed of a large number of continuous monofilaments. A powdered thermoplastic resin attached to each monofilament and captured between the monofilaments, and the opened resin-impregnated reinforced fiber bundle is heated and melted to form a sheet, which is then cooled and solidified. In the method for producing a sheet, at least one group of four or more parallel reinforcing fiber bundles to be introduced into the fluidized bed is divided into a plurality of groups at a predetermined number and each group is arranged in a different position in the fluidized bed. After passing through the guide bar while pressing it, guide the reinforcing fiber bundles of each set to one common guide bar, and stack the adjacent side edges of the opened reinforcing fiber bundles. It is characterized in that the cell 's.

According to a second aspect of the present invention, there is provided a method for producing a fiber composite sheet, which comprises impregnating a resin with the side edges of adjacent reinforcing fiber bundles opened in the first aspect of the invention at the same time as or after the overlapping. It is characterized in that vibration is applied to the reinforcing fiber bundle.

The above-mentioned thermoplastic resin includes a mixture of a thermoplastic resin and a thermosetting resin.

Examples of the reinforcing fiber bundle (roving) include glass fiber, carbon fiber, ceramic fiber, polyamide fiber, polyester fiber and the like, but the softening point thereof must be higher than the melting point of the thermoplastic resin.
If the softening point is below the melting point of the thermoplastic resin, its strength will be lost during heating and melting. The diameter of monofilament is 1
50 μm, particularly 2 to 30 μm is suitable. Diameter is 1μ
If it is less than m, the strength which can withstand the tension generated by the heat-melting step and the amplitude caused by the amplitude cannot be obtained, and the strength as the fiber composite sheet is difficult to be obtained. It is hard to spice.

The optimum value of the tension applied to the reinforcing fiber bundle depends on the diameter of the monofilament.
0gf-3000gf is suitable. Tension is 40
If it is less than 0 gf, the reinforcing fiber bundle is difficult to open and 3000 g
If it is larger than f, the reinforcing fiber may not be able to withstand the tension generated during the take-up until the heating and melting step. Further, it is desirable that the tension be applied to all of the reinforcing fiber bundles in order to uniformly open them.

Further, vinyl acetate, starch, polyester and the like are usually used as a filament sizing agent.
In order to uniformly integrate the thermoplastic synthetic resin, it is necessary to easily open the filament.
Therefore, a small amount of the sizing agent is preferable, and usually 0.1
~ 5 wt% is used.

The number of reinforcing fiber bundles may be any number as long as it is two or more. The number of reinforcing fiber bundles is the number of reinforcing fiber bundles introduced into the fluidized bed, the spacing between the reinforcing fiber bundles in the fluidized bed introducing section, and the fibers to be set. Determined by the spread width.

In order to surely and uniformly open all the reinforcing fiber bundles and to uniformly impregnate them with the thermoplastic resin, the guide bar for each group is provided with a pair of annular projections at predetermined intervals. It is preferable to provide a fine width regulating portion. When there are a plurality of guide bars for each set, the spread width regulating portion may be provided on one of the guide bars or may be provided on all of them. In addition, an opening width regulation jig formed of a metal having a small frictional resistance and a thermoplastic resin such as polytetrafluoroethylene, polypropylene, or polyethylene, which has a pair of annular convex portions and a reinforcing fiber bundle passage portion, is assembled. It may be attached to another guide bar.

The lowest point position of the fluidized bed through which the reinforcing fiber bundles of the respective sets pass so that the amount of impregnation of the powdery thermoplastic resin does not differ due to the difference of the passage paths of the reinforcing fiber bundles of the respective sets. Are preferably the same or close to the same.

When the adjacent side edges of the opened reinforcing fiber bundles are overlapped with each other, the overlapping dimensions may be the same or different with respect to the side edges. It is determined by the width, the spacing between the reinforcing fiber bundles in the fluidized bed introduction section, the molding width dimension, etc.
It is preferably 20 mm, more preferably 2 to 7 mm. If the overlapping dimension is less than 1 mm, the wall thickness at this portion may be thin, and if it is larger than 20 mm, the overlapping portion becomes too thick on the contrary, and the thickness of the sheet varies in the width direction.

The common guide bar may be arranged above the fluidized bed or in the fluidized bed, but the latter position is preferable. When one reinforced fiber bundle is opened and impregnated with the powdery thermoplastic resin, the fiber distribution and the amount of the powdery thermoplastic resin attached tend to be uneven, but this is due to the side edge of each reinforced fiber. Although it can be solved by overlapping the parts, in order to surely compensate for the insufficient amount of the powdery thermoplastic resin adhered to the side edge part, after overlapping is performed and a sufficient amount of fiber is obtained, It is desirable to attach a powdered thermoplastic resin. Therefore, when the opened reinforcing fiber bundle is passed through the plurality of common guide bars while being pressed against each other even after being superposed, it is desirable that at least one of them is arranged in the fluidized bed.

Further, in order to promote opening, vibration may be applied to the reinforcing fiber bundle before entering the fluidized bed, or air may be blown.

Examples of the powdery thermoplastic resin include olefin polymers such as polyethylene and polypropylene, vinyl chloride resins and copolymers thereof, engineering plastics such as polyether sulfone and polyphenylene sulfide. Particle size is 10-300 μm
Is preferred. If the particle size is less than 10 μm or more than 300 μm, good trapping between the monofilaments is not achieved.

As a method of imparting vibration to the resin-impregnated reinforcing fiber bundle, a common guide bar is arranged so as to be movable up and down, and is vertically moved at a constant amplitude, or a direction perpendicular to the moving direction of the reinforcing fiber bundle. There is a method in which a squeeze bar is placed in and a blow is applied to the resin-impregnated reinforcing fiber bundle.

The vibration state of the resin-impregnated fiber bundle is adjusted by the squeeze bar by the vibration amplitude and the number of hits. When the vibration width is small, it is not effective unless the number of hits is increased. Therefore, it is preferable that the vibration amplitude is 1 to 20 mm and the number of hits is 100 to 2000 times / minute. The vibration may be applied at one location or at multiple locations.

[0019]

According to the invention of claim 1, a parallel reinforcing fiber bundle composed of a large number of continuous monofilaments is passed through a fluidized bed of the powdery thermoplastic resin while opening, and the powdery thermoplastic resin is made into each monofilament. In the production method of the fiber composite sheet, the resin-impregnated reinforced fiber bundles that have been adhered to and captured between the monofilaments, and opened to form a sheet, and then cooled and solidified are introduced into the fluidized bed. Since the above-mentioned parallel reinforcing fiber bundles are divided into a plurality of sets at a predetermined number and the positions are different for each set, at least one set of guide bars arranged in the fluidized bed is pressed and passed through. The spread of adjacent reinforcing fiber bundles does not interfere with the opening. If the side-by-side reinforcing fiber bundles are opened while they are aligned in the horizontal direction, the opening will be hindered by the adjacent ones, so that sufficient opening cannot be obtained, which in turn results in powder thermoplasticity of the reinforcing fiber bundle. It is difficult to sufficiently impregnate the resin, and as a result, the fiber distribution and the wall thickness distribution in the width direction of the obtained sheet vary. If the spacing between the reinforcing fiber bundles is wide so that the opening inhibition does not occur, it is easier to open the fibers, but both side edges of the opened reinforcing fiber bundle have a smaller number of filaments than the central portion. The amount of powdered thermoplastic resin adhered is small. Therefore, the obtained sheet also has variations in fiber distribution and wall thickness distribution.

Further, the reinforcing fiber bundles of the respective groups, which are passed through while being pressed against the guide bars for each group, are guided to one common guide bar in common, and the adjacent side edges of the opened reinforcing fiber bundles. Since the parts are overlapped with each other, the number of filaments on both side edges of the reinforcing fiber bundle does not decrease as compared with the central part.

In the method for producing a fiber composite sheet according to the second aspect of the present invention, vibration is applied to the resin-impregnated reinforcing fiber bundle at the same time as the adjacent side edges of the opened reinforcing fiber bundles are overlapped with each other. Since it is applied, the amount of the powdery thermoplastic resin attached in the width direction is made uniform throughout the entire resin-impregnated reinforcing fiber in which the side edges are overlapped.

[0022]

EXAMPLES Examples of the present invention will be described below with reference to the drawings and in comparison with comparative examples.

First, an apparatus used for carrying out the method for producing a fiber composite sheet according to the present invention will be described. In addition,
In the following description, the term “front” means the right direction in FIG. 1.

Example 1 In FIG. 1, a reinforced fiber bundle is provided behind the fluidized bed apparatus (1).
A bobbin (2) wound around (F) is placed, and in front of the fluidized bed apparatus (1), a heating roll (3) and a cooling roll are sequentially installed.
(4), take-up roll (5) and winder (6) are arranged.

The bottom of the tank (7) of the fluidized bed apparatus (1) is a perforated plate.
It is formed by (8), and gas (G) such as air and nitrogen sent from the gas supply path is jetted upward from below the perforated plate (8) through a large number of these holes. As a result, the powdered thermoplastic resin (9) filled in the tank (7) of the fluidized bed apparatus (1) is fluidized by the jetted gas (G) to form a fluidized bed (R).

A guide bar (10) for introduction into the fluidized bed (R) is arranged above the rear part of the tank (7) of the fluidized bed apparatus (1), and is connected to the bobbin (2). Two guide bars (11) to the fluid bed device (1) are arranged in between. Bobbin (2)
The reinforcing fiber bundles (F) unwound from the fibers are arranged in parallel in the guide bar (10) for introducing a fluidized bed, and the apparatus of FIG. 1 uses them as the first set (FA) and the second set (FA). It is introduced into the fluidized bed (R) in two sets of FB). Therefore, the first set (FA) should be located near the bottom of the tank (7), just below the introduction guide bar (10).
The first guide bar (12A) for each group for the second group (FB) and the first guide bar (12B) for the second group (FB) are located at the same level slightly ahead of them.
Are positioned respectively, and the first group (FA) for the second group is located slightly above the first guide bar (12A) for the first group (FA) for the first group (FA).
Guide bar (13A) has a second set diagonally below and near it.
The second guide bar (13B) for each group for (FB) is positioned, and the first guide bar (13A) for the first group (FA) is located near the front wall of the tank (7) in front of the second guide bar (13A) for each group. A common guide bar (14) is located which brings together the set (FA) and the second set (FB).
1st guide bar (12A) for 1st set (FA), 2nd guide bar (13A) for 1st set (FA), 1st guide bar (1) for 2nd set (FB)
2B), the same second guide bar (13B) and common guide bar
Both (14) are present in the fluidized bed (R). A heating roll located in the front of the tank (7) almost above the common guide bar (14).
Guide bar (15) to (3) is located.

FIG. 2 shows a reinforcing fiber bundle arranged in parallel.
Every two (F), 1st set (FA), 2nd set (FB) and 3rd set
(FC) shows a fluidized bed device (21) which is introduced into the fluidized bed (R) separately. The first set (FA) goes through the first guide bar (22A) and the second guide bar (23A) for each set, and the second set (FB) is the first guide bar (22B) for each set. After passing through the second guide bar (23B), the third set (FC) passes through the first guide bar (22C) and the second guide bar (23C) for each set, and the first common guide bar (24). ) And further to the second common guide bar (25) in the fluidized bed (R).

FIG. 3 shows a reinforcing fiber bundle arranged in parallel.
(F) are introduced into the fluidized bed (R) by dividing them into the first set (FA) and the second set (FB), and then from the first set (FA) in the fluidized bed (R). 3rd set (FC), 2nd set (FB) to 4th set (FD)
A fluidized bed apparatus (31) for branching each is shown. Group 1
(FA) goes through the first guide bar (32A) and the second guide bar (33A) for each group, and the second group (FB) is the first guide bar for each group.
Third through the bar (32B) and the second guide bar (33B)
Set (FC) is the 1st set in the 1st guide bar (32A)
After branching from (FA), through the second guide bar (33C) by group, the fourth group (FD) branches from the second group (FB) at the first guide bar (32B) by group. Then, it is led to the first common guide bar (34) via the second group-specific guide bar (33D), and the second common guide bar (3) in the fluidized bed (R).
Guided to 5).

Using the apparatus shown in FIG. 1, a reinforcing fiber bundle (F) 12 composed of a large number of continuous monofilaments from the bobbin (2) 12
The book is rewound by a take-up roll (5) and passed through two guide bars (11) to introduce a fluidized bed.
In (10), after arranging them in parallel in the lateral direction at intervals of 42 mm, every other reinforcing fiber bundle is divided into the first set (FA) and the second set (FB) (see FIG. 4 (a)), the first set. The set (FA) presses this onto the first guide bar (12A) and the second guide bar (13A) of the set, and the second set (FB) of the first guide bar (12) of the set 12
B) and the second guide bar (13B) while being pressed against each other, and each reinforcing fiber bundle was opened to attach the powdery thermoplastic resin (9) to each monofilament and trapped between the monofilaments. After that, the reinforcing fiber bundle of each set (FA) (FB) is guided to one common guide bar (14), and the adjacent side edges of each opened reinforcing fiber bundle are about 3 mm.
Stacked (see Fig. 4 (b)), guide bar above it
It is guided to a heating roll (3) at 230 ° C through (15), and the resin-impregnated reinforced fiber bundle opened by this is heated and melted to form a sheet, which is then cooled and solidified by a cooling roll (4). To obtain fiber composite sheet (S), molding speed 2.0m / m
Wind it up on the winder (6) with in.

As the reinforcing fiber bundle, glass roving (Nittobo # 4400: fiber diameter 23 μm, bundle of 4000 monofilaments, width dimension about 10 mm) was used, and as the powdery thermoplastic resin, chloride having an average particle diameter of 100 μ was used. Stabilizer of vinyl resin (Shin-Etsu Chemical MA800S) 1.5 phr,
A mixture of 0.5 phr lubricant and a super mixer was used.

A cross-sectional view of the obtained fiber composite sheet (S) is shown in FIG. 5. The average thickness of the sheet (S) is 0.
It was 5 mm. In the figure, (16) is glass fiber and (17) is vinyl chloride.

Example 2 This example uses a fluidized bed apparatus (41) in which the position of the common guide bar (14) is 10 mm higher than the upper surface of the fluidized bed (R), as shown in FIG. The same as Example 1 except that

Example 3 This example is based on the first set (FA) as shown in FIG.
1st guide bar (12A) and 2nd guide bar (1)
3A), the first guide bar (12B) for each group for the second group (FB) and the second guide bar (13B) for each group, and the opening width regulating jig (44) for regulating the opening width to 45 mm. Wearing and the 1st set (FA) and 2nd
They are offset from each other so that they can be separated into sets (FB), and at the common guide bar (14), the adjacent sides of the opened reinforcing fiber bundles of the first set (FA) and the second set (FB). The same as Example 1 except that the overlapping width of the edge portions was 3 mm.

The opening width control jig (44) is a polyethylene cylinder having an inner diameter of 30 mm, an outer diameter of 45 mm and a length of 65 mm, and annular protrusions (42) having a width of 10 mm and a height of 5 mm are provided at both ends thereof. The reinforcing fiber bundle passage portion (43) is formed between the annular convex portions (42).

Example 4 This example is shown in FIG. 8 and is located 10 mm below the upper surface of the fluidized bed (R) and corresponds to the common guide bar (54) of Example 1. The guide bar (54) is arranged so that it can move up and down, and the fluidized bed device (51) that also functions as a vibration imparting device for the resin-impregnated reinforcing fiber bundle is used. Same as Example 1 except that vibration is applied to the resin-impregnated reinforced fiber bundle at the same time as overlapping them.

The above-mentioned vibration imparting device and common guide bar (54)
Is an ecene located outside the fluidized bed (R) above it.
(55) is moved up and down via the connecting rod (56).

Embodiment 5 In this embodiment, as shown in FIG. 9, a common guide bar (64) also serving as a vibration imparting device is placed 10 m from the upper surface of the fluidized bed (R).
m Fluidized bed using the fluidized bed equipment (61) placed at a high position
Example 4 is the same as Example 4 except that adjacent side edges of the reinforcing fiber bundles opened outside the (R) are overlapped with each other and vibration is applied to the resin-impregnated reinforcing fiber bundles.

Example 6 This example is similar to Example 4 except that it is moved up and down by the exenes (55) through the connecting rods (56) and is placed 10 mm below the upper surface of the fluidized bed (R). The vibrating device and common guide bar (54) superimpose the adjacent side edges of the reinforcing fiber bundles opened in the fluidized bed (R) and simultaneously apply vibration to the resin-impregnated reinforcing fiber bundle. The same as Example 3 except for the above.

COMPARATIVE EXAMPLE 1 In this comparative example, as shown in FIG. 10, in the lower part of the tank (7) of the fluidized bed apparatus (71), at three positions, rear, center and front, and in the fluidized bed (R). First, second and third common guide bar
(72) (73) (74) are arranged, the parallel reinforcing fiber bundles are not divided into groups, and the first and second common guide bars (72) (73) open the fiber, and the third common guide bar In the bar (74), the same as Example 1 except that adjacent side edges of the opened reinforcing fiber bundles are overlapped.

Comparative Example 2 In this comparative example, the fluidized bed apparatus (1) in Example 1 was used, and 12 reinforcing fiber bundles (F) were rewound by a take-up roll (5), and two guide bars ( 45 mm laterally in the guide bar (10) for introducing the fluidized bed via
After arranging them in parallel at intervals, they are introduced into the fluidized bed (R) by dividing them into a first set and a second set. In the common guide bar (14),
It is the same as Example 1 except that the adjacent side edge portions of the opened reinforcing fiber bundles were not overlapped.

2, 3, 6, 8 to 10, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof is omitted.

The fiber composite sheet obtained in each of the above examples was evaluated as follows, and the results are shown in Table 1.

Measurement of wall thickness distribution The fiber composite sheet was divided into 40 points in the width direction, the wall thickness was measured using a micrometer, and CV was calculated.

Fiber distribution measurement The fiber composite sheet divided into 40 pieces was cut into a length of 50 mm in the same manner as above, the resin component was burned and separated in an electric furnace, the weight of only glass was measured, and the CV value was calculated.

Void Ratio The void ratio was calculated from the actual specific gravity of the above fiber composite sheet measured in water and the specific gravity calculated from the fiber content (fiber specific gravity 2.5, resin specific gravity 1.36).

Bending Strength Measurement Five fiber composite sheets were laminated and press-molded, and the bending strength in the fiber vertical direction was measured by conducting a three-point bending test using an autograph.

[0047]

[Table 1] As is clear from Table 1 above, the fiber composite sheet obtained by the production method of the present invention is excellent in wall thickness distribution, fiber distribution, void ratio and bending strength.

Further, in Comparative Example 1, since the opening of a large number of fiber bundles is not sufficient, the adhered amount of the powdery thermoplastic resin varies and the wall thickness distribution is poor. In Comparative Example 2, since the side edge portions of the opened fiber bundles do not overlap each other, the thickness of that portion is thin and the strength is remarkably reduced.

[0049]

According to the method for producing a fiber composite sheet of the first aspect of the present invention, a parallel reinforcing fiber bundle composed of a large number of continuous monofilaments is passed through a fluidized bed of powdery thermoplastic resin while opening. Since the fibers are not interfered with each other by the adjoining ones when the fibers are pressed, the fibers are sufficiently opened, and the reinforcing fiber bundle is sufficiently impregnated with the powdered thermoplastic resin. Moreover, since the adjacent side edge portions of the opened reinforcing fiber bundles are overlapped with each other, the number of filaments on both side edges of the reinforcing fiber bundle does not decrease compared to the central portion, so that the obtained sheet has voids. The ratio is low and the strength is excellent, and the fiber distribution and wall thickness distribution in the width direction of the sheet are uniform.

According to the method for producing a fiber composite sheet of the invention of claim 2, further, by vibrating the resin-impregnated reinforcing fiber bundle, the width of the entire resin-impregnated reinforcing fiber in which the side edge portions are overlapped with each other is overlapped. Since the amount of the powdery thermoplastic resin adhered in the direction is made uniform, it becomes possible to obtain a sheet which is uniform in the width direction and has a desired thickness.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an entire manufacturing apparatus for a fiber composite sheet used in Example 1 of the present invention.

FIG. 2 is a vertical cross-sectional view of a fluidized bed apparatus that divides parallel reinforcing fiber bundles into three sets.

FIG. 3 is a vertical cross-sectional view of a fluidized bed apparatus that divides parallel reinforcing fiber bundles into four sets.

[Fig. 4] In Example 1 of the present invention, (a) is arranged in parallel in a lateral direction at a constant interval in a guide bar for introducing a fluidized bed, and then divided into two sets every other reinforcing fiber bundle. FIG. 3B is a front view showing the state, in which (b) guides two sets of reinforcing fiber bundles to a common one common guide bar and overlaps the adjacent side edges of each opened reinforcing fiber bundle. It is a front view showing the combined state.

FIG. 5 is an enlarged detailed cross-sectional view of the fiber composite sheet obtained in Example 1 of the present invention.

FIG. 6 is a vertical sectional view of a fluidized bed apparatus used in Example 2 of the present invention.

FIG. 7 is an enlarged plan view of a grouped guide bar with an opening width regulating jig and a common guide bar used in Example 3 of the present invention.

FIG. 8 is a vertical sectional view of a fluidized bed apparatus used in Example 4 of the present invention.

FIG. 9 is a vertical sectional view of a fluidized bed apparatus used in Example 5 of the present invention.

FIG. 10 is a vertical sectional view of a fluidized bed apparatus used in Comparative Example 1.

[Explanation of symbols]

 (9): Powdered thermoplastic resin (12A) (12B) (13A) (13B): Guide bar for each group (14): Common guide bar (F): Reinforcing fiber bundle (FA) (FB): set

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B29L 7:00

Claims (2)

[Claims] 1. A parallel reinforcing fiber bundle composed of a large number of continuous monofilaments is passed through a fluidized bed of a powdery thermoplastic resin while opening the fiber bundle so that the powdery thermoplastic resin is attached to each monofilament. In a method for producing a fiber composite sheet, in which a resin-impregnated reinforced fiber bundle that is captured and opened is heated and melted to form a sheet, and then cooled and solidified, four or more parallel reinforcements that are introduced into a fluidized bed The fiber bundles are divided into a plurality of sets each having a predetermined number of fibers, and each set is placed in a different position, and is passed through at least one guide bar arranged in the fluidized bed while being pressed against the guide bar. To a single common guide bar, and the adjacent side edges of the opened reinforcing fiber bundles are overlapped with each other. 2. The resin-impregnated reinforcing fiber bundle is vibrated at the same time as or after the adjacent side edge portions of the opened reinforcing fiber bundles are overlapped with each other. A method for manufacturing a fiber composite sheet.