JPH02252532A - Production of fiber-reinforced resin sheet - Google Patents

Abstract

PURPOSE:To continuously manufacture a fiber-reinforced resin sheet in which a thermoplastic resin and reinforcing fibers are adhered satisfactorily to each other by a method wherein press rolls with the clearance between the rolls varied as the rolls are rotated are so disposed as to clamp a pair of loop form belts therebetween in a heating region, and the gap between the belts is varied intermittently. CONSTITUTION:A reinforcing fiber 1 is guided by guide rolls 12, 13 and 14 into a fluidized bed 2a, where a powdery thermoplastic resin 2 is adhered to the fiber 1. The fiber 1 is then cut by a rotary cutter 17 to a desired length, and the cut pieces of the fiber are dropped to be supplied onto a mount part 21b of a lower loop form belt 21. The mixture 3 of the cut fibers and the resin 2 sandwiched between the loop form belts 20 and 21, and is supplied to a heating means 22, by which the mixture is heated, and the resin 2 is melted. The upper and lower belts 20, 21 are pressed by the rolls 30, whereby the gap between the belts 20, 21 is varied, and the mixture 3 melted to be fluid is kneaded through upward, downward, leftward, rightward, forward and backward intermittent movements. The bonding between the reinforcing fibers 1 and the resin 2 is accelerated, foams present between the resin 2 and the fibers 1 are removed to the exterior, and the mixture of the resin 2 and the fibers 1 is fed to a cooling means 34, where the mixture is cooled under pressure to form a fiber- reinforced resin sheet having a predetermined thickness.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for producing a fiber reinforced resin sheet in which a thermoplastic resin is impregnated between reinforcing fibers. The present invention relates to a method for producing a fiber-reinforced resin sheet that allows continuous production of resin sheets.

(Prior art) As a method for manufacturing fiber-reinforced resin sheets, a method is proposed in which a mixture of powdered thermoplastic resin and reinforcing fibers is supplied onto a conveyor belt, and the mixture is heated while applying pressure (Japanese Patent Laid-Open No. 59 49929) and the like have been proposed.

In the above method, it is possible to continuously produce a thermoplastic resin composite material in which reinforcing fibers are dispersed relatively uniformly in the thermoplastic resin.

(Problem to be Solved by the Invention) However, if the pressure applied to the mixture is too low, the air bubbles existing between the thermoplastic resin and the reinforcing fibers cannot be completely removed.
There is a problem that the thermoplastic resin and reinforcing fibers cannot be sufficiently bonded.

In addition, in order to improve the adhesion between the thermoplastic resin and reinforcing fibers, a pair of upper and lower concentric rolls with smooth surfaces is installed in the heating area, and the clearance between the upper and lower pair of concentric rolls is gradually narrowed. Therefore, a method of continuously applying pressure to the mixture can be considered.

However, with this method, a homogeneous composite cannot be obtained because the molten mixture spreads too much in the axial direction of the rolls, and reinforcing fibers that are difficult to pass through tend to stay in front of a pair of rolls with a small clearance. There were drawbacks, and there was also the risk that the composite would break during manufacturing.

The present invention solves the above problems, and consists of a continuous fiber-reinforced resin sheet in which reinforcing fibers are uniformly dispersed in a thermoplastic resin matrix, and the flowing thermoplastic resin is impregnated to the surface of the reinforcing fibers and sufficiently bonded. The purpose is to provide a method for manufacturing the same.

(Means for Solving the Problem) The method for producing a fiber-reinforced resin sheet of the present invention involves transferring a mixture of a powdered thermoplastic resin and short reinforcing fibers between a pair of upper and lower endless belts moving in the same direction. A method for producing a fiber-reinforced thermoplastic resin sheet, in which a powdered thermoplastic resin and reinforcing fibers are integrated by supplying the mixture, and passing the mixture through a heating region while being held by the pair of upper and lower endless belts and melting it. In the heating region, one or more pairs of pressure rolls whose clearance between the upper and lower rollers increases and decreases as they rotate are installed to sandwich the upper and lower endless belts, and the gap between the endless belts is intermittently increased. The above object is thereby achieved.

FIG. 1 shows an example of a manufacturing device used in the present invention, and this device includes an unwinding roll 10 for setting a roll around which roving-shaped reinforcing fibers 1 are wound, and a reinforcing fiber 1 sandwiched therebetween. A rotary cutter 17 that unwinds the reinforcing fiber 1 from the roll 10 by rotating in the direction of the arrow in the figure and cuts the reinforcing fiber 1 to a desired size, and a container in which powdered thermoplastic resin 2 is supplied. 11 and container 11
The reinforcing fiber #tti that has passed through is cut into a desired length with a rotary cutter 17, and powdered thermoplastic resin 2 is attached. The heating device includes a pair of upper and lower endless belts 20.21 for transferring the reinforcing fibers 1 to the heating means 22 side, and a cooling means 34 disposed at a rear position of the heating means 22.

A large number of ventilation holes are provided at the bottom of the container 11, and the gas 3 sent from the gas supply path passes through these ventilation holes to the container 1.
It is configured to be supplied to the inside of 1. Therefore, the powdered thermoplastic resin 2 supplied into the container 11 is fluidized by the jetting of the gas 3, and a fluidized bed 2a is formed. Reinforcing fibers 1 are provided inside the container 11 and at the upper end of the wall.
Guide rolls 12, 13, 14, 15 are provided to guide the.

The endless belts 20 and 21 are configured to rotate continuously while being guided by a plurality of rolls, and the upper and lower endless belts 20 and 21 each have a linear transfer section 20as.
21a are formed, and the respective transfer parts 20as 21a are arranged to face each other vertically with a gap in between. The transfer portion 21a of the lower endless belt 21 is longer than the transfer portion 20a of the upper endless belt 20 (and extends further forward than the front end of the transfer portion 20a of the upper endless belt 20, and the extending end portion A mounting portion 21b whose upper part is open is formed at the top.The endless belts 20 and 21 are made of a material having high strength and heat resistance, such as a steel belt, a stainless steel belt, a glass cloth reinforced Teflon belt, etc. be able to.

upper and lower endless bells) 20, 21 transfer portions 20a;
Heating means 22, 22 are provided at opposite locations of 21a, respectively.
are arranged, and a plurality of press rolls 3o are arranged in each heating means 22. As the heating means 22, a heating method using a radiant heat source such as an infrared heater or a far-infrared heater, a heating furnace of an electric heating type or a hot air circulation type, a heating roll or the like are used.

Upper pressing roll 3 arranged above the upper endless belt 20
1a, 32a, 33a, and lower pressure rolls ff1b, 32b, 3 disposed below the lower endless belt 21.
31) are provided at corresponding positions above and below, respectively. As shown in FIG. 2, the pressure roll 30 has a long diameter portion 30a that is a long distance from the center and a short diameter portion 30b that is a short distance from the center. Second
The pressure roll 30 shown in the figure is constructed by providing a plurality of axially long protrusions 37 on the outer peripheral surface of a substantially cylindrical roll body 36 at equal intervals in the circumferential direction, and unevenness is alternately provided on the outer peripheral surface. There is. Therefore, each roll pair 31as bs 32a,
b, 33a, and b are rotationally driven, and for example, when the long diameter portion 30a of the press roll 30 faces toward the endless belt 20.21, the gap between the upper and lower endless belts 20.21 becomes smaller, and the short diameter portion of the press roll 30 30b is an endless bell) 20.2
When facing toward the first side, the gap between the upper and lower endless belts 20.21 becomes larger, and in this way, the upper and lower endless belts 20.2
1, the gap between row pairs 31a, bs 32aSb
, 33aSb will increase and decrease periodically.

The clearance of the press roll 30 is preferably configured to be changeable, so that breakage of the reinforced resin sheet can be reliably prevented. Further, it is more effective to use a plurality of pressure rolls 30 than a pair, and a plurality of pressure roll pairs 3
The distance between the pressure rolls 30 and the transfer speed of the endless belts 20 and 21 may be adjusted so that the large and small parts of the clearance of 0 do not overlap in the same position relative to the passing mixture 3, or It is preferable to use a pressure roll 30 of.

The clearance between the pair of upper and lower press rolls 30 is set so that the gap between the upper and lower pair of endless belts 20 and 21 is within the range of 50% to 150% with respect to the desired thickness of the fiber-reinforced resin sheet. It is preferable to do so. If it falls below 50%,
There is a risk that the fiber-reinforced resin sheet will spread too much in the lateral direction or break during manufacturing. When it exceeds 150%, the pressure applied to the mixture 3 is too small, and the reinforcing fibers 1 and the thermoplastic resin 2 are not sufficiently bonded. Upper and lower pressure rolls 3
The clearance of 0 is such that the gap between the pair of upper and lower endless belts 20 and 21 does not become less than 100% in the entire width direction with respect to the desired thickness of the fiber-reinforced resin sheet during one rotation of each roll 30. If it is not installed, the desired thickness cannot be obtained. The pressure rolls 30 include at least upper and lower pressure rolls 31a, 32as, 33a, or 31b.
, 32b, and 33b may be comprised of rolls having a long diameter part 30a and a short diameter part 30b, and the other roll may be comprised of a circular center roll. Also, the pressure roll 3
0 may consist of a heating roll.

The cooling means 34 is comprised of a pair of upper and lower concentric rolls with smooth surfaces and perfectly circular cross sections, and may also be constructed of a type that cools by blowing air using a blower or the like.

Next, the manufacturing method of the present invention will be explained using the above-mentioned apparatus.

The continuous reinforcing fibers 1 are taken up by a rotary cutter 17 and unwound from the outside of the roll 10 without being twisted, and the reinforcing fibers 1 are removed by a guide roll 12.1.
It is led into the fluidized bed Za while being guided by 3.14, and the powdered thermoplastic resin 2 is deposited thereon.

The reinforcing fiber 1 to which the powdered thermoplastic resin 2 is attached is passed through a guide roll 15 and cut into a desired length by a rotary cutter 17. The short reinforcing fibers 1 to which the powdered thermoplastic resin 2 is attached are placed on the mounting portion 21b of the lower endless belt 21.
Feeds falling on top. This mixture 3 is transferred while being held between a pair of upper and lower endless belts 20 and 21, and is transferred to the heating means 2.
2 and heated, the powdered thermoplastic resin 2 is melted. At the same time, as the gap between the upper and lower endless belts 20 and 21 increases and decreases due to pressure from the rotationally driven roll 30, the mixture 3, which has been sufficiently melted and fluidized by heating, moves intermittently in the vertical, horizontal, and front-back directions. The mixture 3 is kneaded by movement and shearing. As a result, the bonding between the reinforcing fibers 1 and the resin 2 is promoted, and the air bubbles existing between the resin 2 and the reinforcing fibers 1 are removed to the outside. Next, the mixture 3 is sent to the cooling means 34, where it is cooled under pressure to obtain a fiber-reinforced resin sheet of a predetermined thickness.

The reinforcing fibers 1 used in the present invention include inorganic fibers such as fibers that are thermally stable at the melting temperature of the powdered thermoplastic resin 2 used, aramid fibers, econoll fibers, polyester fibers,
Organic fibers such as polyamide fibers are preferably used, and the diameter of the monofilament is preferably 1 to 50 μm. These reinforcing fibers 1 can be used in the form of monofilaments, or in the form of strands or rovings made by converging a large number of monofilaments. When using fibers in a bundled state, the amount of binding agent attached should be 1fi to facilitate the impregnation of the resin between the monofilaments.
The content is preferably 0.5% by weight or less, and more preferably 0.5% by weight or less. It's okay.

Although the length of the reinforcing fiber cut into short dimensions is not specified, it is usually 0.1 to 30 cm, preferably 0.5 to 15 cm. If it is less than 1 cm, a fiber-reinforced resin sheet with excellent mechanical properties cannot be obtained, and if it exceeds 30 cm, it becomes difficult to obtain a homogeneous fiber-reinforced resin sheet.

As the powdered thermoplastic resin 2 used in the present invention, any resin that melts and softens when heated can be used. for example,
polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polyethylene terephthalate,
Polyethylene terephthalate, polycarbonate, polyvinylidene fluoride, polyphenylene sulfide, polyphenylene oxide, polyphenylene ether, polyether ether ketone, etc., and copolymers, graft compounds and blends containing 84 fats as the main component,
For example, ethylene-vinyl chloride copolymer, vinyl acetate-
Ethylene copolymer, vinyl acetate-vinyl chloride copolymer,
Urethane-vinyl chloride copolymer, styrene-butadiene-acrylonitrile copolymer, acrylic acid-modified polypropylene, maleic acid-modified polyethylene, etc. are used.

In either case additives such as stabilizers, lubricants, processing aids, molding agents, dyes, pigments may be blended. Also,
Either a product obtained in powder form during polymerization or a product made into powder form by a pulverizer can be used. The average particle diameter is preferably 2000 μm or less. If it exceeds 2.00 μm, it is likely to be difficult to mix the reinforcing fibers 1 in the fluidized bed za.

In the present invention, the mixing ratio of the reinforcing fibers 1 and the powdered thermoplastic resin 2 supplied to the lower endless belt 2o is appropriately determined depending on the physical properties required of the fiber-reinforced resin sheet. is preferably 5 to b amount%. If it exceeds 70% by volume, it is difficult to obtain a sheet containing the resin uniformly.]2. Furthermore, if the amount of reinforcing fiber 1 is too small, a fiber-reinforced resin sheet with excellent mechanical strength cannot be obtained. As a result, the reinforcing fibers are uniformly dispersed in the thermoplastic resin and are sufficiently bonded, resulting in high strength. In addition, in the present invention, since the mixture 3 is intermittently compressed using the pressure roll 30 whose clearance increases or decreases, the mixture 3 may spread too much in the axial direction of the roll as in the past, or the mixture 3 may stay in front,
For example, the resin that is easy to pass through is sent first, and the mixture containing a large amount of reinforcing fibers 1 does not stagnate (this makes it possible to obtain a homogeneous fiber-reinforced resin sheet.Furthermore, the manufacturing method of the present invention This is particularly effective in cases where superior performance can be obtained by fluidizing the molten resin and promoting gelation, such as with polyvinyl chloride.

In addition, as a method of feeding the mixture 3 between the endless belts 20 and 21, reinforcing fiber material cut into a desired length is fed between the endless belts 21 separately from the powdered thermoplastic resin 2.
7. A method of mixing the thermoplastic resin powder 2 on the endless belt 21. The reinforcing fibers 1 cut to a desired length and the thermoplastic resin powder 2 are mixed in advance and supplied to the endless belt 20.21. Alternatively, any of the methods described in [7] above, such as attaching powdered thermoplastic resin 2 to continuous fibers, cutting the fibers to a desired length, and supplying the fibers to the endless belts 20 and 21, can be adopted.

As mentioned above, the endless belt 20 is made with the thermoplastic resin 2 uniformly dispersed between the monofilaments of the reinforcing fibers 1 in advance.
．． The method of supplying between 21 and 21 is preferable because the reinforcement effect of the reinforcing fibers 1 is high and a fiber-reinforced resin sheet with homogeneous physical properties can be obtained. As a method, as shown in FIG. 1, there is a method in which roving-shaped reinforcing fibers 1 are made to flow through a powder fluidized bed 2a of thermoplastic resin 2 and adhered thereto, and a method in which roving-shaped reinforcing fibers 1 are made to adhere by flowing in a powder fluidized bed 2a of thermoplastic resin 2,
As described in Japanese Patent No. 9929, examples include a method of mixing reinforcing fibers 1 and powdered thermoplastic resin 2 using a jet stream.

The shape of the press roll used in the present invention is not limited as long as it has a long diameter part 30a and a short diameter part 30b as shown in FIG. 2. For example, the shape of the pressure roll shown in FIGS. can be used.

The pressure roll 40 shown in FIG. 3 is composed of a cylindrical body with an elliptical cross section, and has a long diameter portion 40a that is a long distance from the center and a short diameter portion 40b that is a short distance from the center. and has. Press roll 40 having such a configuration
may be arranged as a pair of upper and lower rollers, or only one of them may be the pressure roll 40 having the above configuration, and the other side may be a circular center roll. When a pair of upper and lower pressure rolls 40 is arranged, it is preferable that the long diameter portions 40a of the pressure rolls 40 are rotated in synchronization so that they are opposite to each other, and that adjacent pairs of rolls on the left and right are rotated with a 90' phase difference from each other. It is recommended to set it to .

The pressure roll 50 shown in FIG. 4 is constructed by providing convex portions 52 on the outer peripheral surface of a cylindrical body 51 at appropriate intervals in the circumferential direction and the axial direction, and the pressure roll 60 shown in FIG.
The pressure roll 70 shown in FIG. Twist both ends 180° in the circumferential direction, and make the long diameter part 72.7 of both ends.
2 (or short diameter portion) and the long diameter portion 72 (or short diameter portion) of the intermediate portion are shifted by 90° in the circumferential direction.

When using the pressure rolls 50, 60, and 70 shown in FIGS. 4 to 6, since these pressure rolls have different clearances not only in the circumferential direction but also in the axial direction, the pair of upper and lower endless belts 20, 21 This makes it possible to apply localized pressure J, thereby effectively imparting a kneading action to the fluidized mixture 3 held between the upper and lower endless belts 20 and 21.

(Example) Next, the present invention will be explained based on examples.

A fiber-reinforced resin sheet was manufactured using the apparatus shown in FIG.

As the reinforcing fiber 1, a glass fiber roving (filament diameter 13 μm, 4400 g/Km) was cut into a length of about 5 cm.

As powdered thermoplastic resin 2, a mixture of the following composition was used.

Vinyl chloride resin (degree of polymerization 800, average particle size 300 μm)
...100 parts by weight Stabilizer...3 parts by weight Lubricant...2 parts by weight Reinforcing fiber is 160 g/min, powder thermoplastic resin is 355
It was fed to an endless belt 20.21 g/min.

In the apparatus shown in FIG. 1, the endless belts 20 and 21 are glass cloth reinforced Teflon belts, and the moving speed is 330 m.
A constant speed of m/min was used.

The heating means 22 had a far-infrared heater whose surface temperature was set to about 340°C. The pressure rolls 30 include upper pressure rolls 31a, 32as, 33a shown in FIG. 2, and lower pressure rolls 31b, 32b, 33.
For b, a center roll was used. Upper pressure rolls 31a, 32
The dimensions of a and 33a are 75 mm from the center of the protrusion 37 of the roll, and 65 mm from the center of the recess, and the clearance of each roll pair is determined by the shortest gap between the upper and lower endless belts 20 and 21. , roll pair 31a and 31b,
32a and 32b, 33a and 33b each 4.
011111% 3.51111.3.0m+a. Further, the length of the press roll 30 in the axial direction was set to 300 mm. The clearance of the cooling roll 34 was set to 3.5+n+u.

The obtained fiber reinforced resin sheet had a width of about 300 mm and a thickness of about 3.5 mm, the glass fiber content was 20% by volume, the reinforcing fibers were randomly oriented, and the resin was well impregnated between the reinforcing fibers. there were.

When the obtained fiber reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 18 kg/mm2.
The flexural modulus was 9B (Hg/am2), and the Izod impact value was 95 kg-cm/c12.

A fiber-reinforced resin sheet was obtained in the same manner as in Example 1, except that the glass fiber roving was cut into 0.5 cm pieces.

The obtained fiber-reinforced resin sheet had a width of about 300 cm and a thickness of about 3.5 cm, the glass fiber content was 20% by volume, the reinforcing fibers were randomly oriented, and the resin was well impregnated between the reinforcing fibers. It was something.

When the obtained fiber-reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 16.5 kg/
mm2, flexural modulus was 880 Kg/mm'', and Izod impact value was 90 Kg-C/cm2.

Embodiment 1 In the apparatus shown in FIG.
Fiber-reinforced resin sheets were obtained in the same manner as in Example 1, except that the oval rolls 40 with a major axis of 150 mm and a minor axis of 130 mm shown in FIG. 3 were used as 2a and 33a, respectively.

The obtained fiber-reinforced resin sheet had a width of about 300mm, a thickness of about 3.5mm, and a glass fiber content of 20% by volume.
The reinforcing fibers were oriented in runs and dams, and the resin was well impregnated between the reinforcing fibers.

When the obtained fiber-reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 18 kg/ll1.
i12, flexural modulus was 950 Kg/+m2, and Izod impact value was 100 Kg-cm/crs2.

Nylon-6 was used as the powdered thermoplastic resin 2, the reinforcing fiber was 165 kg/min, and the powdered thermoplastic resin was 225 g.
Example 1 except that the endless belt was fed to a pair of upper and lower endless belts at a constant speed of 25 em/min, and the far-infrared heater was set at a surface temperature of about 395°C. A fiber reinforced resin sheet was obtained in the same manner.

The obtained fiber reinforced resin sheet had a width of about 300 mm and a thickness of about 3.5 mm, the glass fiber content was 25% by volume, the reinforcing fibers were randomly oriented, and the resin was well impregnated between the reinforcing fibers. there were.

When the resulting fiber-reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 17 kg/mm.
The flexural modulus was 800 Kg/mm2, and the Izot impact value was 90 Kg-cm/cI112.

In the apparatus shown in FIG. 1, each pair of rolls 31, 32 .
A fiber-reinforced resin sheet was obtained in the same manner as in Example 1 except that No. 33 was removed.

The obtained fiber reinforced resin sheet has a width of approximately 300111I1
1. The thickness is approximately 3.5 mm, and the glass fiber content is 20
Although the reinforcing fibers were randomly oriented in volume %, the resin was not sufficiently impregnated between the reinforcing fibers.

When the obtained fiber reinforced resin sheet was subjected to a bending test and an eye shift impact test, the bending strength was 8 kg/mm',
Flexural modulus is 380Kg/m2, Izod impact value is 2
It was 5Kg-am/em2.

In the apparatus shown in FIG. 1, the upper pressure roll 313.3
2a, 33a and lower pressure rolls 31b, 32b, 3
3b is a circular center roll, and the clearance between the rolls is such that the gap between the upper and lower pair of endless belts is the same as the gap between the roll pairs 31a and 3.
1b132a and 32b, 33a and 33b each 4
．． A fiber-reinforced resin sheet was obtained in the same manner as in Example 1 except that the weight was set to 0, 3.5 m weight, 3.5 m weight.

The obtained fiber reinforced resin sheet had a width of about 300 mm and a thickness of about 3.5 m, the glass fiber content was 20% by volume, and the reinforcing fibers were randomly oriented.
The resin was not sufficiently impregnated between the reinforcing fibers.

When the obtained fiber reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 11 kg/mm2.
The flexural modulus was 460 Kg/mm'', and the Izot impact value was 38 Kg-cm/am2.

A fiber-reinforced resin sheet was manufactured using the apparatus shown in Fig. 1.

As reinforcing fiber 1, glass fiber roving (filament diameter 13 μm, 4400 g/Km) was used as in Example 1.
) was cut to a length of approximately 5 cm.

As the powdered thermoplastic resin 2, the same mixture as in Example 1 was used.

Reinforcing fiber: tsog/min, powder thermoplastic resin: 405
It was fed to an endless belt 20.21 g/min.

In the device shown in Figure 1, the endless bell) 20.21 uses a glass cloth reinforced Teflon belt, and the moving speed is 300 m.
A constant speed of m/min was used.

The heating means 22 had a far-infrared heater whose surface temperature was set to about 340°C. The rolls 50 shown in FIG. 4 are used as the upper pressure rolls 31a, 32a, 33a, and the lower pressure rolls 31b, 32b, 33b are circular center rolls.
The dimensions of a and 33a are such that the convex portion 52 of the roll is 7 mm from the center.
5, the recess is 65 mm from the center, and the clearance of each roll pair is such that the shortest gap between the upper and lower endless belts 20, 21 is the roll pair 31a and 31b, 32a and 32b,
33a and 33b are each 5°0, 4.0mm.

It was set to be 3.5 mm. In addition, the pressure roll 3
The length of the axial port of 0 was set to 300 mm. The clearance of the cooling roll 34 was set to 3.51.

The obtained fiber-reinforced resin sheet has a width of approximately 300 W+m, a thickness of approximately 4.0 mm, and a glass fiber content of 20% by volume.
The resin was well impregnated between the reinforcing fibers.

When the obtained fiber reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 18.0 kg/a.
m2, flexural modulus was 985 Kg/mm2, and Izod impact value was 97 Kg-cm/cva2.

A fiber-reinforced resin sheet was obtained in the same manner as in Example 5, except that the glass fiber roving was cut into approximately 1 cm pieces.

The obtained fiber-reinforced resin sheet has a width of about 300mm, a thickness of about 4.0IlIn, and a glass fiber content of 20% by volume.
The resin was well impregnated between the reinforcing fibers.

When the resulting fiber-reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 16.5 kg/m.
m2, flexural modulus was 870 Kg/mm2, and Izod impact value was 92 Kg-Cm/cy+2.

In the device shown in Fig. 1, the upper pressure roll 31as
As 32as 33a, a roll 60 shown in FIG. 5 was used. The dimensions of the roll 60 are 75 mm from the center of the convex portion 61 and 65 mm from the center of the concave portion, the press rolls 31a, 33a are Ishinomaki, and the press roll 32 is
A was left-handed. Other than that, a fiber reinforced resin sheet was obtained in the same manner as in Example 5.

The obtained fiber-reinforced resin sheet had a width of about 300mm, a thickness of about 4.0mm, and a glass fiber content of 20% by volume.
The resin was well impregnated into the reinforced W4 fibers.

When the obtained fiber reinforced resin sheet was subjected to a bending test and an eye shift impact test, the bending strength was 18.5 kg/a.
m2, flexural modulus was 950 Kg/mm2, and Izod impact value was 98 Kg-cIl/c112.

In the apparatus shown in FIG. 1, an upper pressing roll 31a,
32as 33a, in the order of major axis 150 shown in Fig. 6,
Short diameter 130IIll! No. 1 deformed roll 70 was used.

In addition, powdered thermoplastic resins 2 and 1. Using nylon-6, reinforcing fibers were supplied in amounts of 190 to 87 minutes, and powdered thermoplastic resin was supplied in amounts of 250 g and 7' to a pair of upper and lower endless belts, and the moving speed of the endless belt was a constant speed of 25 cm/minute. The far-infrared heater was set at a surface temperature of approximately 395°C. Other than that, a fiber reinforced resin sheet was obtained in the same manner as in Example 5.

The obtained fiber reinforced resin sheet has a width of approximately 300111I1
1. Thickness approx. 4. On+m, the glass fiber content was 25% by volume, and the resin was well impregnated between the reinforcing fibers.

When the resulting fiber-reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 17.6 kg/m.
a2, flexural modulus was 810 Kg/mn+2, and Izod impact value was 9 Hg-cra/ea+2.

In the apparatus shown in FIG. 1, each pair of rolls 31.32.
A fiber-reinforced resin sheet was obtained in the same manner as in Example 5, except that No. 33 was removed.

The obtained fiber-reinforced resin sheet had a width of about 300 mm and a thickness of about 4.0 mm, the glass fiber content was 20% by volume, and the resin was not sufficiently impregnated between the reinforcing fibers.

When the resulting fiber-reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 7°5 Kg/mm.
2. The bending elastic modulus was 380 Kg/a+a2, and the Izod impact value was 21 Kg-am/am2. 〇Skin Δ Countermeasure In the apparatus shown in Fig. 1, the upper pressing roll 31a,
32a, 33a and lower pressing rolls 31b, 32b,
33b is a circular center roll, and the clearance between the rolls is set so that the gaps between the upper and lower endless belts are 5.0 mm, 4.0 mm, and 4.0 mm for the roll pairs 31a and 31b, 132a and 32b, and 33a and 33b, respectively. A fiber reinforced resin sheet was obtained in the same manner as in Example 5 except for the above.

The obtained fiber reinforced resin sheet has a width of about 300 mm and a thickness of about 4 mm. OI, the glass fiber content is 20% by volume,
The resin was not sufficiently impregnated between the reinforcing fibers.0 When the obtained fiber-reinforced resin sheet was subjected to a bending test and an Izot impact test, the bending strength was 12.0 kg/m.
m2, flexural modulus was 455 Kg/mm'', and Izod impact value was 35 Kg-cIl/c112.

(Effects of the Invention) According to the method for manufacturing a fiber-reinforced resin sheet of the present invention, the pressing force on the mixture is too strong, causing the mixture to spread too much in the width direction of the belt during manufacturing, and the sheet breaking during manufacturing. Therefore, it is possible to continuously obtain a fiber-reinforced resin sheet in which the thermoplastic resin and reinforcing fibers are sufficiently bonded with each other, with few remaining bubbles.

The sheet obtained by the present invention is not only useful as a plate material having particularly excellent strength and impact resistance, but also can be used as a stampable sheet that is a material for press molding.

4. of. What! Figure 1 is a schematic explanatory diagram of the apparatus used in the method for producing a fiber reinforced resin sheet of the present invention, Figures 2 (a) and (b) are front and side views of the press roll, and Figure 3 (a) ( b) is a front view and a side view of another pressure roll, FIGS. 4 and 5 are perspective views of yet another pressure roll, and FIG. 6(a) is a front view of yet another pressure roll, FIG. (b), (c), and (d) are cross-sectional views taken along lines B-B, C-C, and D-D in FIG. 6(a), respectively.

1... Reinforcing fiber, 2... Powdered thermoplastic resin, 3...
...Mixture, 20.21...Endless belt, 22...
Heating means, 30...press roll.

that's all

Claims (1)

[Claims] 1. A mixture of a powdered thermoplastic resin and short reinforcing fibers is supplied between a pair of upper and lower endless belts moving in the same direction, and the mixture is supplied between the pair of upper and lower endless belts. In a method for manufacturing a fiber-reinforced thermoplastic resin sheet, in which a powdered thermoplastic resin and reinforcing fibers are integrated by passing through a heating region while being held and melted, in the heating region, a pair of upper and lower A fiber-reinforced resin sheet characterized in that a pair or plural pairs of pressure rolls whose clearance between the rolls increases and decreases are installed so as to sandwich the pair of upper and lower endless belts, and the gap between the endless belts is intermittently changed. Production method.