JPH0872154A - Method and apparatus for producing fiber reinforced thermoplastic resin sheet - Google Patents

Abstract

PURPOSE: To arbitrarily control mechanical strength in a specific direction while easily changing the orientation state of a reinforcing fiber by continuously supplying a surfactant-containing aq. dispersion containing the reinforcing fiber, a thermoplastic resin and water to the forming surface of a porous support moved while the inclination of the forming surface with respect to a horizontal plane in an advance direction is changed. CONSTITUTION: A discontinuous reinforcing fiber and a thermoplastic resin are dispersed throughout a surfactant-containing aq. dispersion containing fine air bubbles in a dispersing tank 1. This dispersion is supplied to the surface of the belt like porous support 3 continuously moved through a headbox 2. The headbox 2 has a ceiling plate 23 inclined low forwardly and the dispersion is supplied into the headbox 2 from a rear lower part supply pipe 21. Herein, the inclination of the forming surface 3a of the porous support 3 is inclined when the dispersion of the reinforcing fiber and the thermoplastic resin is supplied to the forming surface 3a and the flow state of the dispersion on the forming surface is controlled to control the fiber orientation state in a formed web, that is, the directionality of mechanical characteristics.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber reinforced thermoplastic resin sheet (also referred to as a stampable sheet) and a device for controlling the direction of mechanical strength.

[0002]

2. Description of the Related Art As a means for imparting the characteristics of high strength and high rigidity while making the most of the molding characteristics of thermoplastic resins,
A composite technique is known in which a reinforcing fiber is added by a high elastic modulus material. Composite thermoplastic resin is lighter,
It is used as a material for various structural members that require high rigidity, corrosion resistance, or high strength. These materials are usually molded and processed after being heated to a temperature above the melting point of the thermoplastic resin that is the matrix, and especially plate-shaped suitable for molding using a press machine and molding of large parts. Alternatively, the sheet-shaped material is also called a stampable sheet, and can be roughly classified into the following two depending on the manufacturing method.

One of them is a fiber reinforced composite in which a continuous fiber or a discontinuous fiber mat is impregnated with a thermoplastic resin. This manufacturing method is generally called a laminating method, and its technique is disclosed in, for example, Japanese Patent Publication No. 54-36193 and Japanese Patent Publication No. 51-14557. The other is a composite in which discontinuous fibers are dispersed in a gas phase or a liquid phase to form a nonwoven fabric-like fiber deposit, which is impregnated with a thermoplastic resin. Of these, the former vapor-phase dispersion is called dry dispersion, and is disclosed in Japanese Patent Application Laid-Open No. HEI 2
-169632, etc.

The latter liquid phase dispersion is called a wet method and is an application of a papermaking technique. In the case of papermaking, the solid content in the dispersion is only pulp, whereas the fiber-reinforced thermoplastic resin is used. In the case of a sheet, a granular resin is generally contained in addition to the fiber chop, and there is a problem that it is difficult to maintain the dispersed state because the shapes and specific gravities of the two are different. A fiber chop and a granular thermoplastic resin are dispersed in an aqueous medium containing an activator, and the dispersion is processed on a porous support to prepare a semi-finished product called a "web" in the form of a nonwoven fabric. Heating the web,
A method of producing a fiber-reinforced thermoplastic resin sheet by solidifying by pressure is adopted. This technology is Japanese Patent Publication Sho 55-91
No. 19, Japanese Patent Publication No. 2-48423 and Japanese Patent Laid-Open No. 60-158227.

FIG. 6 shows a part of FIG. 1 described in Japanese Patent Publication No. 55-9119, and an example of a papermaking apparatus by a wet method will be described. Reference numeral 21 is a supply pipe for supplying a dispersion liquid in which fibers are dispersed in water, 2 is a head box, and 3 is a porous support also called a wire, which is usually endless processed and is also called a mesh belt. 31 is an upstream press roll that conveys the porous support 3, 32 is also a downstream wire roll, 4 is a vacuum suction box arranged below the porous support 3, and 41 is a vacuum therefor. It is a generator.

That is, the porous support 3 is horizontally moved in the direction of the arrow by the pressed roll 31 and the wire roll 32.
The dispersion liquid is supplied to the surface of the head box 2 by the head box 2. The fibers in the dispersion are made into paper, the web remains on the surface of the porous support 3 (hereinafter referred to as the paper making surface 3a), and only water is sucked downward by vacuum. The upper surface of the suction box 4 is the moving suction surface of the porous support body 3, and the lower side of the slit-shaped suction hole communicates with the vacuum generator 41 via the straightening plate.

[0007]

Since the fiber-reinforced thermoplastic resin sheet produced by these methods is excellent in mechanical strength, processability, mass productivity, etc., demand is increasing mainly for structural parts for automobiles. are doing. However, from parts that require high mechanical strength in a specific direction, such as bumper beams, or parts that require appropriate mechanical strength in a specific direction, to change the direction of mechanical strength, such as ceiling materials for passenger cars. The required performance is wide-ranging, even for parts that require a small bias. It is well known that the directionality of such mechanical strength depends on the orientation of the reinforcing fibers in the sheet.

The orientation of the fiber can be quantitatively evaluated by the J value (orientation function) shown below by obtaining the orientation angle distribution f (θ) of the fiber by analyzing the soft X-ray photograph.

[0009]

[Equation 1]

When J = + 1: All the reinforcing fibers are oriented in the reference axis direction When 0: All the reinforcing fibers are oriented completely randomly with respect to the reference axis direction When -1: In the direction perpendicular to the reference axis direction All reinforcing fibers are oriented. There are known some techniques for imparting a high orientation to a specific direction of a fiber-reinforced thermoplastic resin sheet or a technique for imparting a state in which the mechanical strength has a small directional bias (low orientation). For example, in the laminating method, the method disclosed in
There is a method of using continuous fibers in which reinforcing fibers are aligned in one direction as described in JP-A-62-240514, and in the wet method, as described in JP-A-5-44188, reinforcing fibers and a thermoplastic resin are used. There is a method of manipulating the flow path shape of the powder dispersion.

However, these methods require a special material or device for imparting a high orientation or a low orientation, and thus the process is complicated. In addition, the method of arbitrarily controlling the orientation, that is, the method of imparting appropriate mechanical strength in a specific direction has not been mentioned. On the other hand, Japanese Examined Patent Publication No. 51-37366 discloses a paper making apparatus used for paper production, and discloses a web forming apparatus capable of inclining a porous support. This will be described with reference to FIG.

A press roll that conveys the porous support 3.
31, the wire roll 32, and the suction box 4 are attached to an elevating frame 43, and the elevating frame 43 is provided by an elevating device 44 arranged near the front end (downstream side) so that the rotating shaft 42 near the rear end (upstream side). It is possible to change the inclination angle of the papermaking surface 3a with respect to the traveling direction by moving up and down around. However, since the head box 2 is fixed, the papermaking surface 3a
When the inclination angle of the head box 2 changes, a wedge-shaped gap is formed between the head box 2 and the head box 2. Therefore, in the invention disclosed in Japanese Patent Publication No. 51-37366, the side wall extension 26 is attached to the side wall 25 of the head box 2 to close this gap. Therefore, it is necessary to prepare several types of side wall extension bodies 26 having different shapes according to the inclination angle to be changed.

Further, the effect of inclining the porous support 3 is as follows. a) An extremely low concentration dispersion can be used. b) The flow rate of the dispersion can be controlled. c) Since the length of the porous support 3 on which the web is formed is reduced, the apparatus is shortened and the required space is reduced. d) The orientation ratio of the fibers can be controlled to change the properties of the paper.

However, when this technique is applied to the production of a fiber-reinforced thermoplastic resin sheet in which the direction of mechanical strength is controlled, there are the following problems. 1) The rotation axis of the tilting mechanism is behind the head box,
That is, since it is on the upstream side of the flow of the porous support, the height and inclination of the conveying part to the subsequent drying step changes as the angle changes, the tension acting on the semi-finished web changes, and the web becomes May disconnect. 2) The replacement work of the side wall extension body is complicated. 3) The structure is such that the dispersion liquid is stored in the head box and the flow velocity is expected to increase due to the head pressure. However, for the dispersion liquid in which the discontinuous reinforcing fibers and the thermoplastic resin are dispersed in water, flow turbulence occurs. It becomes easy and it is difficult to achieve high orientation of the fiber component.

The present invention solves the above-mentioned problems, changes the orientation state of the reinforcing fibers by a simple operation, and can arbitrarily control the mechanical strength in a specific direction, and a method for producing the same. The purpose is to realize the device.

[0016]

As a result of earnest research, the present inventors have found that when a dispersion of discontinuous reinforcing fibers and a thermoplastic resin is supplied onto a porous support paper-making surface by a wet method, It was found that the fiber orientation state in the formed web, that is, the directionality of the mechanical properties can be controlled by changing the inclination of the organic support and controlling the flow state of the dispersion liquid on the porous support. .

That is, the present invention according to claim 1 is a method for producing a fiber-reinforced thermoplastic resin sheet comprising a discontinuous reinforcing fiber and a thermoplastic resin, wherein the reinforcing fiber and the thermoplastic resin are finely divided by air. Dispersion liquid dispersed in a surfactant-containing aqueous medium containing bubbles, when continuously supplied to the paper-making surface of the moving porous support, to change the inclination of the paper-making surface with respect to the horizontal plane in the traveling direction The method for producing a fiber-reinforced thermoplastic resin sheet is characterized by controlling the direction of mechanical strength.

According to a second aspect of the present invention, the inclination of the papermaking surface in the advancing direction is changed within a range of a depression angle of 0 ° to 10 ° with respect to a horizontal plane, or an elevation angle of 0 ° to 30 ° or less. The method for producing a fiber-reinforced thermoplastic resin sheet according to claim 1, wherein The present invention according to claim 3 provides
The method for producing a fiber-reinforced thermoplastic resin sheet according to claim 1, wherein the reinforcing fibers are glass fibers.

Further, the present invention according to claim 4 is an apparatus for producing a fiber-reinforced thermoplastic resin sheet comprising a discontinuous reinforcing fiber and a thermoplastic resin, wherein the reinforcing fiber and the thermoplastic resin are mixed with a small amount of air. A head box that supplies a dispersion liquid dispersed in a surfactant-containing aqueous medium containing air bubbles onto the paper-making surface of a porous support, and a suction box arranged at the lower part of the paper-making surface, downstream of the paper-making surface. The fiber reinforced thermoplastic resin sheet manufacturing apparatus is characterized in that the fiber reinforced thermoplastic resin sheet is attached to an elevating frame which is tiltable about a rotation shaft arranged on the side.

Further, in the present invention according to claim 5, the mounting position of the dispersion liquid supply pipe to the head box is at the rear end with respect to the direction of the paper making surface, and the ceiling plate of the head box is at the front end and the rear end. 5. The apparatus for producing a fiber-reinforced thermoplastic resin sheet according to claim 4, wherein each is adjustable in the height direction.

[0021]

[Working] The method for producing a fiber-reinforced thermoplastic resin sheet according to the present invention will be described in detail with reference to FIG. 1 is a dispersion tank, 2 is a head box, 3 is a porous support,
4 is a suction box, 5 is a dryer, 6 is a hot press, code A
Head box 2, porous support 3, suction box 4
Hereinafter, the part constituted by is referred to as a paper making device.

The discontinuous reinforcing fiber and the thermoplastic resin are dispersed in a dispersion tank 1 in a surfactant-containing aqueous medium containing air microbubbles. This dispersion liquid is supplied to the surface of the belt-shaped porous support body 3 that continuously moves through the head box 2. The head box 2 has a ceiling plate 23 which is inclined downward toward the front, and the dispersion liquid is supplied into the head box 2 through a supply pipe 21 at the lower rear part.

A vacuum suction box 4 is arranged immediately below the porous support 3, in which the water content of the dispersion, that is, the aqueous solution of the surfactant is suction-separated from the dispersion through the porous support 3. It On the other hand, the non-woven web made of the reinforcing fibers and the thermoplastic resin formed on the porous support 3 is dried by the dryer 5 and wound into a coil if necessary, and then hot pressed 6 Thus, the fiber-reinforced thermoplastic resin sheet is heated and pressed to be dense and solidified.

According to the present invention, when the dispersion liquid of the reinforcing fiber and the thermoplastic resin is supplied onto the papermaking surface 3a, the inclination of the papermaking surface is changed to control the flow state of the dispersion liquid on the papermaking surface.
It is characterized by controlling the fiber orientation state in the formed web, that is, the directionality of mechanical properties. For example, from the fiber-reinforced thermoplastic resin sheet produced by changing the inclination of the papermaking surface while keeping the raw materials and their blending constant, the direction of travel of the porous support (MD direction) and the direction perpendicular thereto (CD direction). Table 1 shows the results of cutting a test piece into a piece and performing a bending test according to JIS K7203.

[0025]

[Table 1]

In the present specification, as shown in FIG. 2 (a), the slope in which the papermaking surface 3a adjacent to the drainage portion of the porous support 3 is inclined upward from the horizontal plane in the traveling direction is the elevation angle. , (B), the inclination in the downward inclined state is defined as the depression angle. When the depression angle state is set, that is, when the papermaking surface 3a is arranged downward, the dispersion liquid supplied to the head box 2 does not collide strongly with the ceiling plate 23 and reaches the front without decreasing the supply flow velocity, so that the reinforcing fiber progresses. Easy to orient. In the web thus prepared, the reinforcing fibers have a highly oriented state. On the other hand, in the elevation state, that is, when the papermaking surface 3a is arranged upward, the dispersion liquid strongly collides with the ceiling plate 23 immediately after being supplied to the head box and stalls, so that a turbulent flow such as swirling occurs. Therefore, it is difficult for the reinforcing fibers to have a directivity. In the web thus prepared, the reinforcing fibers are in a low orientation state. Therefore, by changing the slope of the papermaking surface from the depression angle to the elevation angle, from the stampable sheet with high mechanical strength in the characteristic direction, that is, the belt traveling direction, to the stampable sheet with low mechanical strength directionality. Can be made differently. The case where the papermaking surface is horizontal, that is, 0 ° is a conventional example and is excluded from the present invention.

The slope of the papermaking surface is set as desired, but the depression angle is preferably 10 ° or less and the elevation angle is 30 ° or less. When the gradient exceeds the above range, not only the orientation change of the reinforcing fiber is saturated, but also the equipment becomes large. The length of the reinforcing fiber used in the present invention is preferably 6 to 50 mm in order to obtain its reinforcing effect and ensure dispersion in the surfactant-containing aqueous medium. If the fiber length is too short, a sufficient reinforcing effect cannot be obtained. If the fiber length is too long, the fluidity at the time of molding will decrease.

As the reinforcing fiber, there are glass fiber, carbon fiber, stainless fiber, resin fiber and the like, but glass fiber is most preferable in view of price, balance of characteristics and the like. The matrix resin may be a thermoplastic resin, for example, polyolefin, saturated polyester, polycarbonate,
Examples include polyamide and thermoplastic polyurethane.
Examples of the polyolefin include polyethylene, polypropylene and modified products, copolymers, and mixtures thereof, that is, maleic acid-modified polypropylene, acrylic acid-modified polypropylene, ethylene-propylene copolymer, and the like.

Further, the shape of the matrix resin may be granular, fibrous, powdery or the like, but is not limited to any of them in the present invention, and it may be dispersed in an aqueous medium containing a surfactant. Good. The ratio between the reinforcing fiber and the thermoplastic resin is not particularly limited, but the weight ratio (fiber / resin) in the sheet is preferably 20/80 to 70/30.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, one embodiment of a method for manufacturing a fiber-reinforced thermoplastic resin sheet and an apparatus therefor according to the present invention will be described in detail with reference to the drawings. FIG. 3 is a sectional view showing only the main part of the papermaking apparatus of the present invention, and the reference numerals are the same as those used so far.

As will be described later, this paper making apparatus has a press box 31, a wire roll 32, and a suction box 4 for conveying the porous support 3, and also a head box 2 attached to an elevating frame 43. The feature is that it can move up and down together with the surface. The ceiling plate 23, which is inclined low in front of the head box 2, has its front end and rear end adjustable in the height direction with respect to the papermaking surface.

According to the experiments conducted by the present inventors, the height of the ceiling plate 23 at the rear end, that is, at the dispersion liquid inlet side, affects the orientation of the fibers. When the height of the ceiling plate 23 on the entry side is reduced, the volume of the head box 2 is reduced, the dispersion liquid supplied into the head box 2 reaches further forward, and the decrease in the flow velocity is suppressed. The orientation of the fibers in the web is enhanced. On the contrary, when the height of the ceiling plate 23 on the entrance side is increased, the volume of the head box 2 is increased, so that the forward driving force of the dispersion liquid is lost, and the turbulence of the flow is likely to occur. Fiber orientation is reduced.

In the method of changing the fiber orientation by adjusting the height of the entrance-side ceiling plate 23, the degree of change in the orientation is less than that in the case where the gradient of the papermaking surface is changed. Therefore, this method is suitable for fine adjustment of the orientation state of the fibers after the papermaking is started by setting the gradient of the papermaking surface to a certain value. On the other hand, the height of the ceiling plate 23 at the front end, that is, the web exit side, is adjusted according to the basis weight (weight per unit area) of the manufactured web, and affects the airtightness of the headbox, the moisture content of the web, and the texture. To do.

The position where the dispersion liquid supply pipe 21 is attached to the head box 2 is near the lower end of the rear end, and the dispersion liquid supplied inside from here collides with the ceiling plate 23 in a dispersed state and the papermaking process below is performed. Face to face. A weir plate 22 is also provided inside the supply port. The barrier plate 22 can also be raised and lowered like the ceiling plate 23. FIG. 4 is a front view showing the papermaking apparatus portion in the embodiment. As is clear from comparison with the one shown in FIG. 7, in the present invention, the elevating frame 43 is tilted about the rotary shaft 42 arranged on the downstream side by the elevating device 44 provided on the upstream side so as to adjust the angle of the paper making surface 3a. Can be changed. In this figure, the papermaking surface 3a is set to an elevation angle of about 25 °. The porous support 3 is an endless belt made of a mesh of polyester resin fibers.

FIG. 5 shows the same device in which the lifting device is operated and the elevation angle is changed to about 15 °. Although the path route of the endless belt changes depending on the angle of inclination, the wire roll 32
Since there is almost no change in the path route during the transition from the drying machine to the drying device, the force acting on the manufactured web is always constant, and even if the inclination angle is changed, the web is not cut and the quality is stable.

Although the head box 2 moves up and down together with the paper making surface 3a, it is possible to open and close the head box 2 independently for maintenance of the paper making surface, belt replacement and other maintenance and operation needs. In addition, a hanging hand, a stopper, or the like is appropriately provided for opening / closing work or fixing in an open state. Next, examples of the method for producing the fiber-reinforced thermoplastic resin sheet of the present invention will be specifically described.

Fiber reinforced thermoplastic resin sheets were manufactured by the steps shown in FIG. 1 and by using the apparatus shown in FIGS. 3 to 5 by changing the inclination angle of the papermaking surface for various raw materials. Comparative Example In a dispersion tank 1, an aqueous 0.08 wt% sodium dodecylbenzene sulfonate solution, which is an aqueous medium containing a surfactant, was stirred, and a glass fiber having an average length of 13 mm and a diameter of 11 μm and an average particle diameter were used.
0.9 mm granular polypropylene was added to the aqueous solution in an amount of 0.3% by weight and 0.7% by weight, respectively, and the mixture was stirred and dispersed to prepare a foaming dispersion liquid. 400 mm of effective paper-making width of the porous support 3 which moves this foaming dispersion through the head box 2.
The web was continuously fed onto the paper-making surface 3a to produce a web having a target weight per unit area of 1500 g / m ² . The papermaking surface 3a is horizontal and the ceiling board 23
The height of the rear end from the paper making surface was 80 mm, and the height of the front end was 20 mm.

After drying this web, it was heated and pressed under the conditions of 210 ° C. and 5 kg / cm ² , and then cooled and solidified under the conditions of 20 ° C. and 5 kg / cm ² to obtain a dense sheet. A soft X-ray photograph of this sheet was taken, and the J value, which is the orientation function, was determined from the image analysis of the film. The results are shown in Table 2. Example 1-1 A sheet was produced in the same manner as in the comparative example except that the elevation of the papermaking surface was changed to 30 °, and the J value of this sheet was determined. Table 2 shows the results.

Example 1-2 A sheet was produced in the same manner as in the Comparative Example except that the elevation angle of the papermaking surface was 20 °, and the J value of this sheet was determined. Table 2 shows the results. Example 1-3 A sheet was manufactured in the same manner as in the comparative example except that the elevation angle was 10 °, and the J value of this sheet was obtained. Table 2 shows the results.

Example 1-4 A sheet was manufactured in the same manner as in the comparative example except that the inclination of the papermaking surface was changed to a depression angle of 10 °, and the J value of this sheet was determined. Table 2 shows the results. Example 2-1 A sheet was produced in the same manner as in Example 1-2 except that carbon fiber having a diameter of 7 μm and an average length of 13 mm was used as the reinforcing fiber, and the J value of this sheet was determined. Table 2 shows the results.

Example 2-2 A sheet was produced in the same manner as in Example 2-1 except that the inclination of the papermaking surface was changed to a depression angle of 10 °, and the J value of this sheet was determined.
Table 2 shows the results. Example 3-1 A sheet was produced in the same manner as in Example 1-2 except that stainless fiber having a diameter of 10 μm and an average length of 13 mm was used as the reinforcing fiber, and the J value of this sheet was determined. Table 2 shows the results.

Example 3-2 A sheet was produced in the same manner as in Example 3-1, except that the depression angle of the papermaking surface was 10 °, and the J value of this sheet was determined.
Table 2 shows the results. Example 4-1 A sheet was produced in the same manner as in Example 1-2 except that glass fiber having a diameter of 11 μm and an average length of 25 mm was used as the reinforcing fiber, and the J value of this sheet was determined. Table 2 shows the results.

Example 4-2 A sheet was produced in the same manner as in Example 4-1, except that the depression angle of the papermaking surface was 10 °, and the J value of this sheet was determined.
Table 2 shows the results. Example 4-3 In the foaming liquid in the dispersion tank, a reinforcing fiber having a diameter of 11 μm,
0.2% by weight of glass fiber with an average length of 13 mm and an average particle size of 0.9 mm
0.8% by weight of granular polypropylene is added and stirred,
A sheet was produced in the same manner as in Example 1-2 except that the dispersion was adjusted to prepare a foamed dispersion, and the J value of this sheet was determined. Table 2 shows the results.

Example 4-4 A sheet was produced in the same manner as in Example 4-3 except that the depression angle of the papermaking surface was changed to 10 °, and the J value of this sheet was determined.
Table 2 shows the results. Example 4-5 In the foaming liquid in the dispersion tank, a reinforcing fiber having a diameter of 11 μm,
0.5% by weight of glass fiber with an average length of 13 mm and an average particle size of 0.9 mm
0.5% by weight of granular polypropylene is added and stirred,
A sheet was produced in the same manner as in Example 1-2 except that the dispersion was adjusted to prepare a foamed dispersion, and the J value of this sheet was determined. Table 2 shows the results.

Example 4-6 A sheet was produced in the same manner as in Example 4-5 except that the depression angle of the papermaking surface was 10 °, and the J value of this sheet was determined.
Table 2 shows the results. Example 5-1 A sheet was produced in the same manner as in Example 1-3, except that the height of the rear end of the ceiling plate 23 from the papermaking surface was 120 mm and the height of the front end was 20 mm. The value was calculated. Table 2 shows the results.

Example 5-2 A sheet was produced in the same manner as in Example 1-3 except that the height of the rear end of the ceiling plate 23 from the papermaking surface was 40 mm and the height of the front end was 20 mm. The J value of the sheet was determined. Table 2 shows the results.

[0047]

[Table 2]

[0048]

According to the present invention, it is possible to provide a fiber-reinforced thermoplastic resin sheet (stampable sheet) in which the directional strength of mechanical strength is arbitrarily controlled. As a result, it can be used for all structural members that are large-sized molded products using a press machine or the like, are required to be lightweight and have high rigidity, and the direction of mechanical strength is specified.

[Brief description of drawings]

FIG. 1 is a schematic view of a process for producing a fiber-reinforced thermoplastic resin sheet by a wet method of the present invention.

FIG. 2 is an explanatory diagram of an inclination angle of a papermaking surface of a porous support according to the present invention.

FIG. 3 is a cross-sectional view showing a main part of a papermaking apparatus in an example of the present invention.

FIG. 4 is a front view showing a papermaking apparatus in an example of the present invention.

FIG. 5 is a front view showing a papermaking apparatus according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a part of a manufacturing apparatus showing a conventional technique.

FIG. 7 is an explanatory view showing a manufacturing apparatus showing another conventional technique.

[Explanation of symbols]

 1 Dispersion tank 2 Headbox 3 Porous support 3a Paper making surface 4 Suction box 5 Dryer 6 Hot press 21 Supply pipe 22 Barrier plate 23 Ceiling plate 25 Side wall 26 Side wall extension 31 Prest roll 32 Wire roll 41 Vacuum generator 42 Rotation Axis 43 Lifting frame 44 Lifting device

Front page continuation (72) Inventor Ayo Takehara 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Fumiaki Yoshikawa 2-3 2-3 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Inside the corporation (72) Inventor Chiharu Takagi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Works Chiba Works

Claims (5)

[Claims] 1. A method for producing a fiber-reinforced thermoplastic resin sheet comprising discontinuous reinforcing fibers and a thermoplastic resin, wherein the reinforcing fibers and the thermoplastic resin are added to a surfactant-containing aqueous medium containing air microbubbles. When continuously supplying the dispersed dispersion liquid onto the papermaking surface of the moving porous support, the directionality of the mechanical strength is controlled by changing the inclination of the papermaking surface with respect to the horizontal plane in the traveling direction. A method for producing a fiber-reinforced thermoplastic resin sheet, comprising: 2. The inclination of the papermaking surface to the traveling direction is more than 0 ° in the depression angle and less than 10 ° in the horizontal plane or more than 0 ° in the elevation angle 30.
The method for producing a fiber-reinforced thermoplastic resin sheet according to claim 1, wherein the temperature is changed within the range of ° or less. 3. The reinforcing fiber is glass fiber.
Alternatively, the method for producing the fiber-reinforced thermoplastic resin sheet according to item 2. 4. An apparatus for producing a fiber-reinforced thermoplastic resin sheet comprising discontinuous reinforcing fibers and a thermoplastic resin, wherein the reinforcing fibers and the thermoplastic resin are added to a surfactant-containing aqueous medium containing air microbubbles. A head box (2) for supplying the dispersed dispersion liquid onto the paper-making surface (3a) of the moving porous support (3) and a suction box (4) arranged below the paper-making surface (3a). , An elevating frame (43) that is tiltable about a rotary shaft (42) arranged downstream of the papermaking surface (3a)
An apparatus for manufacturing a fiber-reinforced thermoplastic resin sheet, characterized by being attached to a. 5. The ceiling plate (23) of the headbox (2), wherein the position of attachment of the dispersion liquid supply pipe (21) to the headbox (2) is at the rear end with respect to the direction of the papermaking surface (3a). 5. The apparatus for manufacturing a fiber-reinforced thermoplastic resin sheet according to claim 4, wherein the front end and the rear end are each adjustable in the height direction.