JPH054246A - Method for manufacturing fiber composite sheet - Google Patents

Abstract

(57) [Summary] [Purpose] The distribution of the thermoplastic resin and the fibers can be made uniform, and a fiber composite sheet with little variation in physical properties can be obtained with high productivity. [Structure] First, a reinforcing fiber bundle (F1) consisting of a large number of continuous monofilaments is passed through a fluidized bed (R) of a powdery thermoplastic resin, and each monofilament of the fiber bundle (F1) is mixed with the powdery thermoplastic resin. Apply resin. Next, the resin-attached fiber bundle (F
2) is cut into a predetermined length, and the cut resin-attached fibers (F3) are brought into contact with a number of fins (9) provided at predetermined intervals on the rotary shaft (8) from above, and then the predetermined intervals are set. Of the upper and lower endless belts (10) and (11) facing each other in the gap
b) Drop on top and collect. Finally, the cutting resin-attached fiber aggregate (F4) is fed into the gap between the two endless belts (10) and (11), and the heating and cooling area ( 12) (13) pass through the sheet (S)
To form.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a tough plate material,
The present invention relates to a method for producing a fiber composite sheet used as a so-called stampable sheet or the like, which is a press molding material for obtaining various products.

[0002]

2. Description of the Related Art As a method for producing a fiber composite sheet,
(B) Mixing reinforced short fibers and powdered thermoplastic resin in a jet stream of compressed air and dropping them on a net to accumulate them, then transfer the aggregates to a moving endless belt, heating and pressurizing and cooling. To form a sheet (JP-A-59-49929)
(See Japanese Patent Laid-Open Publication No. 2004-135), and (b) the reinforced short fibers and the powdery thermoplastic resin are mixed in a container while keeping them in a fluid state, taken out of the container, dropped on a moving endless belt, and accumulated, A method is known in which a sheet is fed into a gap between moving upper and lower endless belts which are opposed to each other at a predetermined interval, heated and pressed, and then cooled to form a sheet (JP-A-62-2).
08914 publication).

[0003]

In the method for producing a fiber composite sheet of the above (a), since the reinforcing short fibers having different specific gravities and the powdery thermoplastic resin are mixed in an air stream and fall-accumulated, There is a problem that the distribution of the fibers and the resin becomes non-uniform and the physical properties of the obtained sheet vary greatly. Further, in the method (b) for manufacturing a fiber composite sheet, the reinforcing short fibers and the powdery thermoplastic resin are mixed in a container, and therefore the batch system is inevitably obtained, and thus the sheet is continuously obtained. However, there is a problem that productivity is poor.

The object of the present invention is to disperse reinforcing fibers in units of monofilaments and to sufficiently impregnate the thermoplastic resin even between the monofilaments, and to evenly distribute the thermoplastic resin and the fibers so that there is little variation in physical properties. It is to provide a method capable of producing a fiber composite sheet with high productivity.

[0005]

According to a first aspect of the present invention, there is provided a method for producing a fiber composite sheet, wherein a reinforcing fiber bundle composed of a large number of continuous monofilaments is passed through a fluidized bed of powdery thermoplastic resin. Of attaching the powdery thermoplastic resin to each of the monofilaments, cutting the resin-attached fiber bundle to a predetermined length, and cutting resin-attached fibers at a predetermined interval on at least one rotating shaft. After passing through the gap between the fins by contacting the above fins from above, the upper and lower endless belts, which are opposed to each other at a predetermined interval, are dropped onto the feeding part and accumulated.
A step of feeding the cut resin-adhered fiber aggregate into the gap between the two endless belts, sandwiching it with the moving two endless belts, and passing it through a heating and cooling region to form a sheet. is there.

The method for producing a fiber composite sheet according to the invention of claim 2 is characterized in that the fins are disk fins.

The method for producing a fiber composite sheet according to the third aspect of the present invention is characterized in that the fin is provided with a required number of corners on the periphery thereof.

As the reinforcing fibers, fibers that are thermally stable at the melting temperature of the thermoplastic resin used are used. Specific examples thereof include glass fibers, carbon fibers, silicon / titanium / carbon fibers, boron fibers, fine metal fibers, aramid fibers, liquid crystal polymer fibers, polyester fibers, and polyamide fibers.

The diameter of the monofilament is preferably 1 to 50 μm. When using a large number of continuous monofilaments as a reinforcing fiber bundle, a sizing agent may or may not be used,
When used, the amount of the sizing agent attached is preferably 1% by weight or less, more preferably 0.5% by weight or less. When the amount of the sizing agent attached exceeds 1% by weight, it becomes difficult to separate the fiber bundle into monofilament units in the fluidized bed, and the impregnability of the thermoplastic resin between the monofilaments decreases.

The reinforcing fiber bundle is in the form of a strand or a roving in which hundreds to thousands of continuous monofilaments are formed. In consideration of the width, thickness, production speed, etc. of the fiber composite sheet to be produced, a large number of the reinforcing fiber bundles are usually used in parallel.

As the powdery thermoplastic resin, any resin that is melted and softened by heating can be used. For example, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyvinylidene fluoride, polyphenylene sulfide, polyphenylene oxide, polyether sulfone, polyether ether ketone, etc. are used. Further, copolymers or graft resins or blend resins containing the above-mentioned thermoplastic resin as a main component, for example, ethylene-vinyl chloride copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-vinyl chloride copolymer, urethane-vinyl chloride. Copolymers, acrylonitrile-butadiene-styrene copolymers, acrylic acid-modified polypropylene, maleic acid-modified polyethylene and the like can also be used. And the thermoplastic resin, a stabilizer, a lubricant,
Additives such as processing aids, plasticizers and colorants may be incorporated. Further, both a thermoplastic resin obtained in powder form at the time of polymerization and a thermoplastic resin made into powder form by a pulverizer can be used. The average particle size is preferably 2 mm or less. When the average particle size exceeds 2 mm, it becomes difficult to uniformly adhere to the monofilaments of the reinforcing fiber bundle in the fluidized bed.

The ratio of the thermoplastic resin to the reinforcing fiber is appropriately determined according to the required physical properties of the fiber composite sheet.
The reinforcing fibers in the sheet are preferably 5 to 70% by weight. If the reinforcing fiber content is less than 5% by weight, the mechanical strength of the sheet will not be sufficient, and if it exceeds 70% by weight, it will be difficult to obtain a sheet uniformly impregnated with a thermoplastic resin.

The length of the cut resin-adhered fiber is usually 0.5 to
It is 500 mm, and particularly preferably 5 to 150 mm. If the length of the cut resin-adhered fiber is less than 0.5 mm, the reinforcing effect of the sheet is small, and if it exceeds 500 mm, it becomes difficult to obtain a homogeneous fiber composite sheet.

[0014]

In the method for producing a fiber composite sheet according to the present invention, first, a reinforcing fiber bundle composed of a large number of continuous monofilaments is passed through a fluidized bed of a powdery thermoplastic resin.
In the fluidized bed, the reinforced fibers are separated and opened into monofilament units by the jetting of gas or the rubbing and rubbing of the powdery thermoplastic resin generated in the fluidized bed, and the powdery thermoplastic resin is separated between the monofilaments. Penetrate and are electrically captured and attached to each monofilament. Then, the resin-attached fiber bundle is cut into a predetermined length, and the cut resin-attached fiber is
Since a large number of fins provided at predetermined intervals on at least one rotating shaft are brought into contact with each other from above and pass through the gaps between the fins, the filaments of the fiber bundle are uniformly dispersed. In this way, the cut resin-adhered fibers in which the filaments are evenly dispersed are dropped and accumulated on the feeding part into the gap between the upper and lower endless belts which are opposed to each other at a predetermined interval, and the cut resin-adhered fiber aggregate is collected. The thermoplastic resin is sufficiently impregnated between the monofilaments because it is fed into the gap between the two endless belts and is passed through the heating and cooling regions while being sandwiched by the moving two endless belts. As a result, the thermoplastic resin and the fibers are evenly distributed.

[0015]

【Example】

First Embodiment First, an apparatus used for carrying out the present invention will be described with reference to the drawings. In the following description, the term “front” means the right direction in FIG. 1.

The fiber composite sheet manufacturing apparatus shown in FIG. 1 has an unwinding roll (1) around which a reinforcing fiber bundle (F1) is wound, and is arranged in front of the unwinding roll (1) and filled with a powdery thermoplastic resin. A fluidized bed device (2) equipped with a tank, a pair of upper and lower scrapers (3) arranged in front of the fluidized bed device (2), and a widening means (4) arranged in front of the scraper (3). , Widening means
(4) and a take-up drive roll (5) and a pinch roll (6) for rewinding the reinforcing fiber bundle (F1) from the rewind roll (1), and in front of the pinch roll (6) The rotary cutter (7) facing the take-up drive roll (5) below, and a large number of circles arranged at a predetermined interval between the drive roll (5) and the rotary cutter (7). Rotating shaft (8) having plate fins (9) and upper and lower endless belts (10) (1
1) and heating means (12) and cooling means which are sequentially arranged from the rear side with respect to the opposing transfer parts (10a) (11a) of both endless belts (10) (11)
(13) and the rear end of the lower endless belt (11) is made to project rearward from the upper endless belt (11), and the transfer part (11
The rear extension of a) is located below the rotary shaft (8) with fins (9) and serves as a feeding part (11b) into the gap between the endless belts (10) and (11). The transfer unit (11
Instead of extending a) to form the feeding part (11b), another endless belt may be arranged at the same place to provide the feeding part.

The tank bottom of the fluidized bed apparatus (2) is formed by a perforated plate (14), and gas (G) such as air or nitrogen sent from the gas supply passage is below the perforated plate (14). It is ejected upwards through a large number of holes. As a result, the powdery thermoplastic resin filled in the tank of the fluidized bed apparatus (2) is fluidized by the jetted gas (G) to form a fluidized bed (R). A guide bar (15) for guiding the fiber bundle (F1) is provided inside the tank of the fluidized bed apparatus (2) and at the upper ends of the front and rear walls thereof.

As the widening means (4), there are used two fixing bars which are arranged at a predetermined interval and whose front is positioned above the rear.

FIG. 2 is an enlarged view of one finned rotary shaft (8) having a large number of disc fins (9) at predetermined intervals. The thickness, diameter, and mutual spacing of the disc fins (9) should be adjusted according to the length and amount of the cut resin-attached fibers (F3) so that the cut resin-attached fibers (F3) always contact the disc fins (9). It is determined. Also, the peripheral speed of the disc fin (9) is
Cut resin-attached fibers (F3) are retained, and these are disc fins (9).
The peripheral speed of the rotary cutter (7) should be higher than that of the rotary cutter (7), so that it cannot pass through the gaps between them. The disc fins are not limited to flat ones, and as shown in FIG. 5, circular fins (wavy in a concave-convex shape on both sides provided on the rotary shaft (38) at predetermined intervals ( Something like 39) could also be used. Therefore, "disc fins" include not only flat fins but also corrugated ones on both sides. Further, the diameter of the rotating shaft (8) can be appropriately determined as necessary and is arbitrary.

The two endless belts (10) and (11) are continuously driven in substantially the same direction by driving one of upper and lower pulleys (16) and (17) respectively by a motor (not shown). It is designed to move at the same speed. Further, the rear part of the transfer part (10a) of the upper endless belt (10) is inclined rearward and upward, and the gap between the vertical transfer parts (10a) (11a) widens rearward. The upper and lower endless belts (10) and (11) are formed of, for example, steel, stainless steel, glass cloth reinforced Teflon or the like having high strength and heat resistance.

As the heating means (12), an electric heating type or hot air circulating type heating furnace is used, and the upper and lower endless belts (10) and (11) may be passed through them, or the upper and lower endless belts ( A plurality of pairs of heating rolls may be used that directly press the transfer units (10a) and (11a) of (10) and (11) from above and below and heat directly. Inside the heating means (12) and inside the upper and lower cooling means (13), a plurality of pairs of guide rolls (18) and (19) are arranged at corresponding positions in the vertical direction. ) (19) is adjustable. As the cooling means (13), there is used a blower for blowing air to cool the transfer parts (10a) (11a) of the upper and lower endless belts (10) (11). The guide roll (19) itself may be cooled.

Using the above apparatus, a reinforcing fiber bundle (F1) 1 composed of a large number of continuous monofilaments from the rewinding roll (1) 1
Take the two rolls and drive the roll (5) and pinch roll
(6) Rewind while not twisting,
Passing through the fluidized bed (R) of powdered thermoplastic resin,
Powdered thermoplastic resin is attached to each monofilament of (F1).

As the powdery thermoplastic resin, super.
A mixture prepared in advance with the following formulation using a mixer was used.

Polyvinyl chloride resin (average degree of polymerization: 400, average particle size: 150 μm): 100 parts by weight butyltin maleate: 3 parts by weight Polyethylene wax: 0.5 parts by weight Stearyl alcohol: 1 part by weight Reinforcing fiber bundle As (F1), a roving-like glass fiber bundle having a width of about 8 mm formed by concentrating 4000 monofilaments having a diameter of 23 μm (a bunching agent amount of about 0.3% by weight) was used.

The resin-attached fiber bundle (F2) is passed between a pair of upper and lower scrapers (3), and the scraper (3) removes excess powdery thermoplastic resin to remove the powdery thermoplastic resin and the reinforcing fibers. Adjust so that the weight ratio is 7: 3. By thus adjusting the gap between the pair of upper and lower scrapers (3), the amount of the powdery thermoplastic resin attached can be adjusted.

The resin-attached fiber bundle (F
The width 2) is made wider by the widening means (4) than the original width, that is, the width of the reinforcing fiber bundle (F1) before resin adhesion. The degree of widening is generally about 1.2 to 50 times the original width, preferably about 2 to 50 times, but here, it is about 3.75 of the original width.
Double the width to 30mm.

The widened resin-attached fiber bundle (F2) is passed between the take-up drive roll (5) and the pinch roll (6), and then the rotary cutter (7) is used to make the length about 25.
Cut into mm to make short-sized cut resin-attached fibers (F3).

[0028] Cut resin-attached fiber (F3) to disk fin (9)
The rotating shaft (8) is attached from above to pass through the gap between the fins (9) and open into monofilament units,
After being uniformly dispersed, the upper and lower endless belts (10) and (11) are naturally dropped on the feeding part (11b) into the gap and accumulated. The accumulation amount is 600 mm in width and the feeding part (11) of the lower endless belt (11).
At the center of b), 33 over a range of about 500 mm
It was set to 20 g / m ² . Collection at this time (F4)
The apparent thickness was about 32 mm.

As the rotary shaft (8) with the disc fin (9),
A disc fin with a diameter of 190 mm and a thickness of 1 mm provided on a rotating shaft of 600 mm at intervals of 30 mm.
The peripheral speed of (9) was set to 50 m. The upper and lower endless belts (10) (11) are made of glass cloth reinforced Teflon with a width of 600 mm and a thickness of about 1 mm.
A belt was used.

The cut resin-attached fiber assembly (F4) is 580 mm
Adjusting the minimum gap between the endless belts (10) and (11) to about 2.1 mm by the upper and lower guide rolls (18) while sandwiching between the upper and lower endless belts (10) and (11) that move at a speed of / minute. About 1500 mm in length by pressing the resin-attached fiber aggregate (F4) in the thickness direction
In the heating furnace (12) as a heating means in which hot air of about 200 ° C. is circulated, the powdery thermoplastic resin is melted and the molten resin is impregnated between the filaments. Collection
By pressing (F4) in the thickness direction, the molten thermoplastic resin flows and fills the voids between the monofilaments, and the thermoplastic resin and the reinforcing fibers are surely integrated.

Subsequently, the mixture of the resin and the reinforcing fiber in a molten state is pressed by adjusting the minimum gap between the upper and lower endless belts (10) and (11) to about 2 mm by the upper and lower guide rolls (19), and It cooled by the cooling blower (13) as a cooling means, and the fiber composite resin sheet (S) was obtained. This fiber composite resin sheet (S) has a width of about 500 mm and a thickness of about 2 mm,
The thermoplastic resin was well impregnated between the filaments, and the filaments were uniformly dispersed.

A test piece of 30 mm × 30 mm was randomly cut out from 5 places of the above-mentioned fiber composite sheet of 500 mm × 2000 mm and treated at 700 ° C. for 5 hours to incinerate and remove the resin content, and the glass fiber content was determined. It was measured. Also 20mm
A 150 mm × 150 mm test piece was cut out, and a three-point bending test was performed at a distance between fulcrums of 120 mm to measure bending strength. The results are shown in Table 1.

[0033]

[Table 1]

Embodiment 2 This embodiment uses the apparatus of FIG. 1 in which two rotary shafts (28) with disk fins (29) are combined, as shown in FIGS. 3 and 4. Is. Ie, length 600
The two disc fins (29) with the disc fins (29) having a diameter of 190 mm and a thickness of 1 mm provided at intervals of 50 mm on the rotation shaft (28) of mm, two disc fins (29) 100mm away from the center of
The disc fins (29) were meshed with each other with a gap of 25 mm. The front rotary shaft was rotated counterclockwise and the rear rotary shaft was rotated clockwise, and the peripheral speed of each was set to 50 m.

As the powdery thermoplastic resin, a frozen pulverized powder of pellet polypropylene resin (average particle size 200 μm) is used.
m) and as a reinforcing fiber bundle (F1), the diameter is 23 μm.
Width of about 4000 monofilaments of about 8
mm roving glass fiber bundle (approx.
10% by weight) were used.

The resin-attached fiber bundle (F2) obtained through the same steps as in Example 1 was passed between a pair of upper and lower scrapers (3) to remove excess powdery thermoplastic resin by the scraper (3). It is removed and adjusted so that the weight ratio of the powdery thermoplastic resin and the reinforcing fiber is 6: 4.

The fiber bundle (F2) with the amount of resin adhered is widened by the widening means (4) to a width of 50 mm, which is about 6.25 times the original width.

The widened resin-attached fiber bundle (F2) is cut by a rotary cutter (7) to a length of about 25 mm to obtain a cut resin-attached fiber (F3) having a short dimension.

The cut resin-attached fiber (F3) is brought into contact with the meshed rotating shaft (28) with two disc fins (29) from above to pass between the fins (29) and then the upper and lower endless belts.
(10) Drop and accumulate on the feeding part (11b) into the gap of (11). The accumulation amount was set to 3600 g / m ² over a range of about 500 mm at the center of the feeding part (11b) of the lower endless belt (11) having a width of 600 mm. The apparent thickness of the aggregate (F4) at this time was about 45 mm.

500 mm of the cut resin-attached fiber aggregate (F4)
While moving between the upper and lower endless belts (10) and (11) having the same structure as in Example 1 moving at a speed of 1 / min, the upper and lower guide rolls (18) were used to set the minimum gap between the endless belts (10) and (11) The powdery thermoplastic resin is melted by passing it through a heating furnace (12) having a length of about 1500 mm and a hot air of about 210 ° C. circulated by adjusting the molten resin between filaments. Impregnate.

Subsequently, the mixture of the resin and the reinforcing fiber in the molten state is pressurized by adjusting the minimum gap between the upper and lower endless belts (10) and (11) to about 3 mm by the upper and lower guide rolls (19) and cooled. A fiber composite resin sheet (S) was obtained by cooling with a blower (13). This fiber composite resin sheet (S) has a width of about 5
The thickness was 00 mm and the thickness was about 3 mm, and the thermoplastic resin was well impregnated between the filaments, and the filaments were uniformly dispersed.

In the same manner as in Example 1, the glass fiber content and bending strength of the fiber composite sheet were measured. The results are shown in Table 2.

[0043]

[Table 2]

In this embodiment, two rotary shafts with disc fins are used, but the number and arrangement of rotary shafts with disc fins are arbitrarily determined as necessary, and will be described later, for example. The number and arrangement may be as shown in FIGS. 7 and 8.

Example 3 Nylon-6 resin powder (average particle size: about 80 μm) was used as the powdery thermoplastic resin, and 6000 monofilaments with a diameter of 7 μm were bundled together as a reinforcing fiber bundle to a width of about 6 mm. 10 roving polyacrylonitrile-based carbon fiber bundles were used.

As the rotary shaft with a disk fin, the same structure as in Example 1 was used, but the disk fin (9) had a diameter of 100 mm, a thickness of 2 mm, and a peripheral speed of 70 m. Different from that of the first embodiment.

The resin-attached fiber bundle (F2) obtained through the same steps as in Example 1 is passed between a pair of upper and lower scrapers (3), and the excess powdery thermoplastic resin is removed by the scrapers (3). Then, the weight ratio of the powdery thermoplastic resin and the reinforcing fiber is adjusted to be 7.5: 2.5.

The fiber bundle (F2) with the amount of adhered resin adjusted is widened by the widening means (4) to a width of 25 mm which is about 4.17 times the original width.

The widened resin-attached fiber bundle (F2) is cut by a rotary cutter (7) to a length of about 50 mm to obtain a cut resin-attached fiber (F3) having a short dimension.

The cut resin-attached fiber (F3) is put into a disk fin (9).
After contacting the rotating shaft (8) with the fins from above and passing through the gap between the fins (9), the endless belts (10) and (11) are dropped onto the feeding part (11b) and accumulated. . The accumulation amount is 600 mm in width and the feeding part (11b) of the lower endless belt (11)
3750 over the range of about 500 mm in the center of the
It was made to be g / m ² . The apparent thickness of the aggregate (F4) at this time was about 30 mm.

The cut resin-attached fiber assembly (F4) is set to 500 mm.
The upper and lower endless belts (10) and (11) having the same structure as those of the first embodiment moving at a speed of 1 / min. About 3.2 mm
The powdery thermoplastic resin is melted by passing through a heating furnace (12) having a length of about 1500 mm and a circulating hot air of about 240 ° C., and the molten resin is impregnated between filaments.

Subsequently, the mixture of the resin and the reinforcing fiber in a molten state is further pressurized by adjusting the minimum gap between the upper and lower endless belts (10) and (11) to about 3 mm by the upper and lower guide rolls, and then the cooling blower ( It was cooled by 13) to obtain a fiber composite resin sheet (S). This fiber composite resin sheet (S) has a width of about 5
The thickness was 00 mm and the thickness was about 3 mm, and the thermoplastic resin was well impregnated between the filaments, and the filaments were uniformly dispersed. In the same manner as in Example 1, the glass fiber content and bending strength of the fiber composite sheet were measured. The results are shown in Table 3.

[0053]

[Table 3]

Embodiment 4 In this embodiment, in the apparatus of FIG. 1, the fin is not a disk, and four corners (50) are provided on the periphery of the fin (49) as shown in FIG. It is the one using the thing. That is, the length of one side is 82 mm on the rotating shaft (48) with a length of 600 mm.
2 square fins (49) with a thickness of 1 mm provided at intervals of 25 mm are used, and fins (4) having four corners (50) on the periphery are used.
The peripheral speed of 9) was set to 50 m.

As the powdery thermoplastic resin, one which was previously mixed with a spar mixer in the following formulation was used.

Polyvinyl chloride resin (average degree of polymerization 540, average particle size 150 μm): 100 parts by weight butyltin maleate: 3 parts by weight Polyethylene wax: 0.5 parts by weight Stearyl alcohol: 1 part by weight Dioctyl phthalate: As the 5 parts by weight reinforcing fiber bundle (F1), a roving glass fiber bundle obtained by consolidating 4000 monofilaments having a diameter of 23 μm was used.

The cut resin-adhered fiber (F3) obtained through the same steps as in Example 1 was contacted from above the rotary shaft (48) with fins (49) having four corners (50) on the periphery. After the fibers are opened into monofilament units and uniformly dispersed, the upper and lower endless belts (10) and (11) are naturally dropped and accumulated on the feeding portion (11b) into the gap. The accumulated amount is about 5 at the center of the feeding part (11b) of the lower endless belt (11) with a width of 600 mm.
It was set to be 5230 g / m ² over a range of 00 mm. The apparent thickness of the aggregate (F4) at this time was about 50 mm.

The upper and lower endless belts (10) and (11) have a width of 600 m.
A glass cloth reinforced Teflon belt having a thickness of m and a thickness of about 1 mm was used.

The cut resin-attached fiber assembly (F4) is 580 mm
Adjusting the minimum gap between the endless belts (10) and (11) to about 3.1 mm by the upper and lower guide rolls (18) while sandwiching between the upper and lower endless belts (10) and (11) moving at a speed of 1 / min. About 1500 mm in length by pressing the resin-attached fiber aggregate (F4) in the thickness direction
In the heating furnace (12) as a heating means in which hot air of about 200 ° C. is circulated, the powdery thermoplastic resin is melted and the molten resin is impregnated between the filaments.

Subsequently, the mixture of the resin and the reinforcing fiber in a molten state is pressurized by adjusting the minimum gap between the upper and lower endless belts (10) and (11) to about 3 mm by the upper and lower guide rolls (19) and cooled. It was cooled by a blower (13) to obtain a fiber composite resin sheet (S). This fiber composite resin sheet (S) has a width of about 5
The thickness was 00 mm and the thickness was about 3 mm, the thermoplastic resin was well impregnated between the filaments, and the filaments were uniformly dispersed.

In the same manner as in Example 1, the glass fiber content and bending strength of the fiber composite sheet were measured. The results are shown in Table 4.

[0062]

[Table 4]

Embodiment 5 In this embodiment, in the apparatus of FIG. 1, as shown in FIG. 7, a rotary shaft (58) having eight corners (60) radially provided on the periphery of a fin (59). However, the driving rolls (5) and the rotary cutters (7) are arranged in a line by sequentially shifting the driving rolls (5) and the rotary cutter (7) from the lower middle to four diagonally lower front. That is, a rotating shaft (58) with a length of 600 mm has a length of 82 mm on each side.
12.5 mm thick fins (59) that are formed by rotating one square around the other by 45 degrees around the center
The peripheral speed was set to 50 m by using those provided at intervals of mm.

As the powdery thermoplastic resin, a frozen pulverized powder of pellet polypropylene resin (average particle size 200 μm) is used.
m) and the reinforcing fiber bundle (F1) has a diameter of 23 μm.
roving glass fiber bundle with a width of about 8 mm, which is formed by bundling 4000 monofilaments of m.
10 (3% by weight) were used.

The resin-attached fiber bundle (F2) obtained through the same steps as in Example 1 was passed between a pair of upper and lower scrapers (3) to remove excess powdery thermoplastic resin by the scraper (3). It is removed and adjusted so that the weight ratio of the powdery thermoplastic resin and the reinforcing fiber is 5.5: 4.5.

The resin-attached fiber bundle (F2) is passed between the take-up drive roll (5) and the pinch roll (6), and then cut to a length of about 25 mm by the rotary cutter (7),
Short cut resin-attached fiber (F3).

The cut resin-adhered fiber (F3) is brought into contact with any of the four rotary fins (59), opened into monofilament units and uniformly dispersed, and then the upper and lower endless belts (1
(0) It is naturally dropped and collected on the feeding part (11b) into the gap of (11). The accumulation amount was set to 4910 g / m ² over the range of about 500 mm at the center of the feeding part (11b) of the lower endless belt (11) having a width of 600 mm. The apparent thickness of the aggregate (F4) at this time was about 45 mm.

The cut resin-adhered fiber aggregate (F4) is set to 500 mm.
Adjusting the minimum gap between the endless belts (10) and (11) to about 3.2 mm by the upper and lower guide rolls (18) while sandwiching the upper and lower endless belts (10) and (11) moving at a speed of 1 / min. About 1500 mm in length by pressing the resin-attached fiber aggregate (F4) in the thickness direction
Then, the powdered thermoplastic resin is melted by passing through a heating furnace (12) in which hot air of about 210 ° C. circulates to impregnate the molten resin between the filaments.

Subsequently, the mixture of the resin and the reinforced fiber in the molten state was pressed and cooled by adjusting the minimum gap between the upper and lower endless belts (10) and (11) to about 3 mm by the upper and lower guide rolls (19). It was cooled by a blower (13) to obtain a fiber composite resin sheet (S). This fiber composite resin sheet (S) has a width of about 5
The thickness was 00 mm and the thickness was about 3 mm, and the thermoplastic resin was well impregnated between the filaments, and the filaments were uniformly dispersed.

In the same manner as in Example 1, the glass fiber content and bending strength of the fiber composite sheet were measured. The results are shown in Table 5.

[0071]

[Table 5]

Embodiment 6 In this embodiment, in the apparatus of FIG. 1, as shown in FIG. 8, a rotary shaft (58) having eight corners (60) radially provided on the periphery of a fin (59). Are arranged 6 rows diagonally downward and sequentially in a line.
Using the rotating shafts (58) with (59) arranged in one row by sequentially shifting the rotating shafts (58) three diagonally downwards, each rotating shaft (58) was rotated at a peripheral speed of 50 m in the direction of the arrow in FIG. 7. .

As the powdery thermoplastic resin, nylon-6 is used.
Monofilament 600 with a diameter of 7 μm is used as the reinforcing fiber bundle (F1) using resin powder (average particle size of about 80 μm).
Ten roving-like polyacrylonitrile-based carbon fiber bundles, which are bundles of 0 bundles, were used.

The resin-attached fiber bundle (F2) obtained through the same steps as in Example 1 was passed between a pair of upper and lower scrapers (3) to remove excess powdery thermoplastic resin by the scraper (3). It is removed and adjusted so that the weight ratio of the powdery thermoplastic resin and the reinforcing fiber is 3: 1.

The resin-attached fiber bundle (F2) is passed between the take-up drive roll (5) and the pinch roll (6), and then cut to a length of about 50 mm by the rotary cutter (7),
Short cut resin-attached fiber (F3).

The cut resin-adhered fiber (F3) is brought into contact with any of the nine rotary fins (59), opened into monofilament units and uniformly dispersed, and then the upper and lower endless belts (10).
It is naturally dropped and accumulated on the feeding part (11b) into the gap of (11). The accumulation amount was set to 2600 g / m ² over the range of about 500 mm at the center of the feeding part (11b) of the lower endless belt (11) having a width of 600 mm. The apparent thickness of the aggregate (F4) at this time was about 32 mm.

The cut resin-adhered fiber aggregate (F4) was cut to 500 mm.
Adjusting the minimum gap between the endless belts (10) and (11) to about 2.1 mm by the upper and lower guide rolls (18) while sandwiching between the upper and lower endless belts (10) and (11) that move at a speed of / minute. About 1500 mm in length by pressing the resin-attached fiber aggregate (F4) in the thickness direction
In the heating furnace (12) in which hot air of about 240 ° C. is circulated, the powdery thermoplastic resin is melted and the molten resin is impregnated between the filaments.

Subsequently, the mixture of the resin and the reinforcing fiber in a molten state is pressurized by adjusting the minimum gap between the upper and lower endless belts (10) and (11) to about 2 mm by the upper and lower guide rolls (19) and cooled. It was cooled by a blower (13) to obtain a fiber composite resin sheet (S). This fiber composite resin sheet (S) has a width of about 5
The thickness was 00 mm, the thickness was about 2 mm, the thermoplastic resin was well impregnated between the filaments, and the filaments were uniformly dispersed.

In the same manner as in Example 1, the glass fiber content and bending strength of the above fiber composite sheet were measured. The results are shown in Table 6.

[0080]

[Table 6]

The shape of the fins provided with the corners on the peripheral edge is not limited to that of the third to fifth embodiments. Further, the angle of the corner is 90 degrees in Examples 3 to 5, but this is also 9
It is not limited to 0 degree. The angle of the corner is appropriately determined depending on the type of fiber used, the length and amount of the cut resin-adhered fiber, and the like, and is preferably 30 to 120 °. When it exceeds 30 degrees, the reinforcing fibers become entangled in the corners and the uniform dispersibility deteriorates, and when it exceeds 120 degrees, the opening and dispersing effect of the reinforcing fibers by the corners deteriorates.

Further, as for the rotary shaft with fins having the required number of angles on the periphery, only one may be used as in the third embodiment, or a plurality of rotary shafts may be used as in the fourth and fifth embodiments. You may use. The arrangement in the case of a plurality of cases is appropriately determined by the type of fibers used and the length and amount of the cut resin-adhered fibers, but the maximum rotation outer circumferences of the fins do not mesh, and the distance between the maximum rotation outer circumferences of the fins is The length is preferably 3 times or less. When the fins mesh with each other, the reinforcing fibers agglomerate between the fins and the dispersibility of the fibers deteriorates. When the distance between the maximum rotation outer circumferences of the fins exceeds three times the length of the cut resin-adhered fibers, the reinforcing fibers become fins. And the effect of opening and dispersing the reinforcing fiber by the fin is lost.

[0083]

According to the production method of the present invention, the reinforcing fibers are well dispersed in the monofilament unit, and the reinforcing fibers are sufficiently impregnated with the resin even between the monofilaments, so that the reinforcing effect of the reinforcing fibers is high. Since the fiber composite sheet has excellent physical properties and the reinforcing fiber and the resin are evenly distributed, a fiber composite sheet having uniform physical properties can be obtained. Moreover, productivity is good because the process is continuous.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional side view of the entire apparatus used to practice the present invention.

FIG. 2 is an enlarged plan view of a rotary shaft with a disk fin used in each of Examples 1 and 3.

FIG. 3 is a side view of two rotary shafts with disk fins used in a second embodiment.

4 is a plan view of the rotary shaft with two disc fins in FIG. 3. FIG.

FIG. 5 is a perspective view showing a modified example of a disc fin.

FIG. 6 is a side view of a rotary shaft having a fin provided with a required number of corners on the peripheral edge thereof, which is used in Embodiment 4, and a take-up drive roll, a pinch roll, and a rotary cutter above the rotary shaft.

FIG. 7 is a side view of a predetermined arrangement of rotary shafts having fins provided with a required number of corners on the periphery used in Example 5, and a take-up drive roll, a pinch roll, and a rotary cutter above the rotary shaft. is there.

FIG. 8 is a side view of a predetermined arrangement of rotary shafts having fins provided with a required number of corners on the periphery and a take-up drive roll, a pinch roll, and a rotary cutter above which are used in Example 6; is there.

[Explanation of symbols]

(R) Fluidized bed of powdered thermoplastic resin (F1) Reinforced fiber bundle (F2) Resin-attached fiber bundle (F3) Cut resin-attached fiber (F4) Cut resin-attached fiber aggregate (8) (28) (38) (48) (58) rotating shaft (9) (29) (39) (49) (59) Fins (60) Corner (10) Upper endless belt (11) Lower endless belt (11b) Feed section (12) Heating means (13) Cooling means (S) Fiber composite sheet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area B29K 105: 12 B29L 7:00

Claims (3)

[Claims] 1. A step of: passing a reinforcing fiber bundle composed of a large number of continuous monofilaments through a fluidized bed of powdery thermoplastic resin, and adhering the powdery thermoplastic resin to each monofilament of the fiber bundle; b) a step of cutting the resin-attached fiber bundle to a predetermined length; and c) bringing the cut resin-attached fibers into contact with a large number of fins provided at predetermined intervals on at least one rotation shaft from above to form gaps between the fins. After passing through, the process of dropping and stacking the upper and lower endless belts facing each other at a predetermined interval into the gap between the upper and lower endless belts, and And a step of forming a sheet by passing through a heating and cooling region while sandwiching it with both moving endless belts. 2. The method for producing a fiber composite sheet according to claim 1, wherein the fin is a disk fin. 3. The method for producing a fiber composite sheet according to claim 1, wherein the fin is provided with a required number of corners on the periphery thereof.