JP2002192526A - Method of supplying fiber and thermoplastic resin material to plasticizer and plasticizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent clogging of a material supply path even when supplying a long fiber having a small bulk specific gravity when supplying a fiber and a thermoplastic resin material to a plasticizer, and to provide a fiber. To stabilize the mixing ratio of the resin and the thermoplastic resin material. SOLUTION: When fibers (L1) and (L1) and a thermoplastic resin material (P) are supplied to a common material supply path and both are supplied to a plasticizing apparatus at the same time, granular or granular material is supplied to a cylindrical material supply path. While the powdery thermoplastic resin material (P) is being charged, the fibers (L1) (L1) having an average fiber length of 3 mm to 50 mm are placed at the downstream or downstream of the thermoplastic resin material (P) in the material supply path. ) Is supplied, and the thermoplastic resin material (P) is supplied to the plasticizing device so as to wrap the fibers (L1) and (L1) in the material supply path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for supplying fibers and a thermoplastic resin material to a plasticizing apparatus, and is applied to, for example, an injection machine for molding a fiber-reinforced resin molded article. be able to.

[0002]

2. Description of the Related Art Conventionally, when a molded article made of a fiber reinforced resin is injection-molded, a thermoplastic resin material is melted and kneaded with the fiber by an extruder as a plasticizing device. A fiber-reinforced resin pellet in which the reinforcing fiber is contained in the resin is produced, supplied to the injection machine, melted and kneaded again, and then supplied into the mold, and thereafter, the fiber-reinforced resin in the mold is supplied. There is known one which is cooled and cured to form a molded article.

As an injection molding apparatus having an extruder for kneading a fiber and a thermoplastic resin, Japanese Patent Application Laid-Open No. 4-28 is disclosed.
The one disclosed in No. 6617 is known. In this apparatus, a thermoplastic resin supply port and a fiber supply port on the downstream side thereof are provided in a cylinder of an extruder, and the cylinder is provided with a thermoplastic resin material supplied from the thermoplastic resin supply port. The fiber fed from the fiber supply port is added to the heated and melted resin while heating, and the fiber is melted and kneaded on the downstream side. Then, injection molding is performed using the fiber reinforced resin obtained as described above.

According to this method, a molded article made of a fiber-reinforced resin can be formed only by supplying fibers from a fiber supply port provided in a cylinder of an extruder. There is an advantage that the injection molding can be performed by substantially the same operation as the molding. However, in this case, it is necessary to separately provide a thermoplastic resin supply port and a fiber supply port in the cylinder of the extruder, and to ensure that the fibers from near the fiber supply port bite into the screw in the cylinder smoothly. Therefore, there is a drawback that a screw design such as making the screw a deep groove is required.

As another apparatus for injection molding a molded article made of fiber reinforced resin, the invention of Japanese Patent Application Laid-Open No. 2-153714 has been proposed. In this method, the thermoplastic resin material and the fiber are directly supplied to a cylinder of an injection machine as a plasticizing device. However, even in this case, it is necessary to separately form a thermoplastic resin supply port and a fiber supply port in the cylinder. It is necessary to provide a pushing device for pushing the fibers into the cylinder at the fiber supply port.

An invention disclosed in Japanese Patent Application Laid-Open No. 6-8278 discloses an invention for eliminating the above-mentioned disadvantages of the conventional injection molding apparatuses. This is to supply the thermoplastic resin material and the fiber together to the injection machine through a single material supply path.

[0007]

However, this method has the following problems. . The fibers adhere to the inner wall surface of the hopper as the material supply path due to static electricity or the like, and there is a concern that the material supply path may be clogged due to the fibers. In particular, when long fibers are used in order to lengthen the fibers remaining in the final molded product, the clogging is liable to occur because the bulk specific gravity becomes small.

[0008] The fiber mass that adheres and grows on the inner wall surface of the material supply path collectively enters an extruder or an injection machine, and the mixing ratio of the fiber and the thermoplastic resin material becomes unstable. Therefore, when a molded article made of fiber reinforced resin is produced using this technique, the quality of the molded article cannot be stabilized.
Further, when the mixing ratio is unstable, the time from supply to an injection machine or the like until the thermoplastic resin material is melted is not constant. Since the quality changes, it is not possible to stabilize the quality of the molded product from this point.

[0009] The present invention has been made in view of such a point, and even when supplying a long fiber having a small bulk specific gravity,
It is an object of the present invention to prevent clogging of a material supply path and to stabilize a mixing ratio of a fiber and a thermoplastic resin material.

[0010]

The technical means of the first aspect of the present invention for solving the above-mentioned problem is that "the fiber and the thermoplastic resin material are fed into a common material supply path and both are plasticized at the same time. A method of supplying the material to the apparatus, wherein the material supply path is constituted by a double cylinder of an outer cylinder and an inner cylinder disposed coaxially in an upper part of the outer cylinder, between the inner cylinder and the outer cylinder. While feeding a granular or powdery thermoplastic resin material, a fiber having an average fiber length of 3 mm to 50 mm is charged into the inner cylinder, and the fiber is wrapped in the outer cylinder downstream from the lower end of the inner cylinder. Supplying a thermoplastic resin material. "

According to the above technical means, the fed fibers flow down the material supply path so as to be wrapped in the granular or powdery thermoplastic resin material in the material supply path. Therefore, even if fibers are likely to adhere to the inner wall surface of the material supply passage, the fibers move downstream together with the resin material so as to be washed away by the thermoplastic resin material. That is, the fibers are removed so as to be washed away by the thermoplastic resin material, and the fibers do not accumulate in the material supply path. Further, since the thermoplastic resin material comes into contact with the inner wall surface of the material supply path and the fiber is injected into the inside thereof, the fiber is located at the center side in the material supply path.

According to the second aspect of the present invention, in which the wall surface of the material supply path is vibrated, it is possible to more reliably prevent fibers from adhering to the inner wall surface of the material supply path. Further, the density of the mixed fiber and the thermoplastic resin material is increased by the vibration. Like the invention of claim 3,
When the plasticizing device is an injection machine or an extruder, and the downstream end of the material supply path is connectable to a material receiving port (37) of the injection machine or the extruder, the fibers and the thermoplastic resin are used. The method of supplying the material to the plasticizing device can be effectively used for an injection machine or an extruder.

According to a sixth aspect of the present invention, there is provided an apparatus for supplying a fiber and a thermoplastic resin material to a plasticizing apparatus having a common material supply path into which the fiber and the thermoplastic resin material are charged, comprising: A material supply path constituted by a double cylinder of an inner cylinder disposed coaxially at an upper portion in the outer cylinder, and a granular or powdery thermoplastic resin material is charged between the inner cylinder and the outer cylinder. Resin injection means, and an average fiber length in the inner cylinder of 3 mm to 50 mm
Fiber input means for inputting the fibers, and at the timing when the thermoplastic resin material is input to the material supply path, the resin input means and the fiber input means such that the fibers are input into the inner cylinder. Control device to operate. "
According to this, it is possible to provide an apparatus for supplying fibers and a thermoplastic resin material to a plasticizing apparatus for implementing the invention of claim 1.

According to a seventh aspect of the present invention, "the resin supply section in the material supply path in the resin supply means is the same as the fiber supply section in the material supply path in the fiber supply means. It is more preferable that the resin input section and the fiber input section are arranged vertically.

[0015] In the invention according to claims 6 and 7, "a vibration generator for vibrating the wall surface of the material supply path is provided."
According to the eighth aspect of the present invention, by vibrating the wall surface of the material supply path, the adhesion of the fiber to the material supply path can be more reliably prevented. In addition, the density of the fiber and the thermoplastic resin material in the material supply path increases due to the vibration.

[0016] In the invention of claim 6, in the invention of claim 9, the apparatus comprises "a vibration generating device for vibrating at least one of the inner cylinder and the material supply path". By vibrating at least one of these, it is possible to reliably prevent fibers from adhering to these wall surfaces.

The fiber input means, which is the invention-specifying matter of the sixth invention, may be a roving cutter (1) or a fixed-quantity feeder for supplying the fibers quantitatively as in the invention of the thirteenth invention. Various feeding devices can be used.

[0018]

As described above, according to the first aspect of the present invention, the input fibers flow down the material supply path so as to be wrapped in the thermoplastic resin material in the material supply path. It does not adhere to the wall of the material supply path,
Even when a long fiber having a low bulk specific gravity is supplied, the inside of the material supply path is not clogged.

Further, since the fibers do not adhere to and remain on the inner wall of the material supply passage, the ratio of the fibers to the thermoplastic resin material can be stabilized. Therefore, when a molded article made of fiber reinforced resin is produced using the invention of claim 1, a molded article of good quality in which the mixing ratio of the fiber and the thermoplastic resin material is stable is obtained. Claim 2
According to the second aspect of the present invention, the vibration of the wall surface of the material supply path can more reliably prevent the fiber from adhering to the inner wall surface of the material supply path, so that the effect of the first aspect becomes more remarkable.
Further, since the density of the mixed fiber and the thermoplastic resin material increases due to the vibration of the wall surface of the material supply path, when the mixture is supplied to an injection machine or an extruder and heated and kneaded, the thermoplastic resin is used. The time required for the material to melt is stabilized.

According to the invention of claim 6, it is possible to provide an apparatus for carrying out the invention of claim 1. Since the fibers are supplied into the inner cylinder surrounded by the outer cylinder, the risk of the fibers adhering to the outer cylinder serving as a material supply path is further reduced, and the inner cylinder or the like is vibrated. Adhesion can be more reliably prevented.

[0021]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a state in which the fiber and thermoplastic resin material supply device according to the embodiment of the present invention is connected to a screw type injection machine (3) as a plasticizing device.

In this apparatus, a roving cutter (1) for quantitatively supplying fibers is used as the fiber input means, and a resin input means for inputting a thermoplastic resin material upstream of the fiber input section. As a quantitative feeder (2)
Is used. However, the fiber feeding means is not limited to the roving cutter (1), but may be a quantitative feeder for quantitatively chopped strand fibers cut in advance to a predetermined length. Also, the resin charging means is not limited to the above-described quantitative feeder (2) as long as it can supply the thermoplastic resin material quantitatively.

The lower end of the hopper (4) is connected to a material receiving port (37) formed in the upper wall near the upstream end of the cylinder (39) of the injection machine (3). Is the material supply path described above. In the upper part of the hopper (4),
An inner cylinder (5) for feeding fibers is provided.
(4) and the inner cylinder (5) are arranged coaxially to form a double cylinder. Therefore, in this embodiment, the hopper (4) corresponds to the outer cylinder as the invention specifying matter of the first aspect of the present invention.

A roving cutter (1) is provided above the inner cylinder (5) so that fibers cut to a predetermined length are introduced into the inner cylinder (5). . The thermoplastic resin material is fed from the hopper (4) and the inner cylinder (5) through the chute (6) inclined at an angle that allows the thermoplastic resin material to flow naturally from the fixed-quantity feeder (2). It has become.
In this embodiment, the injection machine (3) is provided at the lower end of the hopper (4).
However, a screw type extruder or the like for melting the thermoplastic resin material and kneading the fiber with the thermoplastic resin material may be connected. In this case, the extruder or the like has already been described.
Etc. correspond to a plasticizing device which is an invention specific matter of the invention.

Hereinafter, each part of the apparatus will be described in more detail. [About roving cutter (1)] Roving cutter
(1) As shown in FIGS. 1 and 2, a feed roll (11) for feeding a large number of long reinforcing fibers (L) (L) wound up on a reel (19) in a flattened state. (11) and a cutting roll (12) provided on the outlet side thereof and longer than the transfer width of the long reinforcing fibers (L) (L), wherein the cutting roll (12) is a lower feed roll. It is provided with a plurality of blades (121) (121) that are in rotation with respect to (11). Therefore, the blade (121) (121) and the feed roll (11)
According to (11), the long reinforcing fiber (L) is a fixed length fiber (L1) (L
Cut to 1).

Further, the cutting roll (12) is adapted to rotate clockwise in FIG. 1, whereby the fibers (L1) and (L1) surely fall into the inner cylinder (5). It is configured as follows. In this embodiment, a long reinforcing fiber
Four 2400 tex roving glass fibers as (L) are fed to feed rolls (11) and (11), whereby fibers (L1) and (L1) having a length of 14 mm are obtained. The fibers (L1) (L1) from the roving cutter (1)
The drop amount in 1) is set to 2.2 kg / min.

The cutting length of the long reinforcing fiber (L) by the cutting roll (12) is determined by the length of the cutting roll (12).
Is determined by the pitch of the blade (121) (121)
The length of the fiber (L1) (L1) formed by the cutting is 3 mm
It can be set in the range of ５０50 mm. fiber
(L1) It was confirmed that even when the length of (L1) was set in the above range, it could be smoothly supplied to the downstream side by the hopper (4) and the screw (31). The fibers actually cut (L1) (L
1) Since the length has some errors, the length is 3 mm to 50 mm.
mm may slightly exceed the range, but it is sufficient that the average fiber length falls within the range. [About the fixed-quantity feeder (2)] A fixed-quantity feeder as a resin charging means for charging the thermoplastic resin material to the hopper (4).
(2) As shown in FIG. 3, a resin hopper (21) for storing a thermoplastic resin material in the form of a pellet, and the resin hopper (21)
And a conveyor (22) for quantitatively supplying the thermoplastic resin material from the chute to the chute (6).
The downstream end of (6) penetrates into the hopper (4) and extends to near the outer wall of the inner cylinder (5) (see FIG. 1). Therefore, the hopper
(4) Chute serving as resin input part of thermoplastic resin material
The tip of (6) is located upstream of the lower end of the inner cylinder (5), which is the fiber feeding section. The tip of the chute (4)
It may be at the same height position as the lower end of the inner cylinder (5).

The method of attaching the chute (6) to the hopper (4) is not particularly limited, but as shown in FIG.
The center axis of (6) is slightly offset from the center axis of hopper (4), and the direction of the granular or powdery thermoplastic resin material injected from chute (6) is
It is preferable not to intersect with the central axis. In this case, the thermoplastic resin material input from the chute (6) falls down while sliding in the circumferential direction on the inner wall surface of the hopper (4). Spirally wrapping the hopper (4)
It is easy to flow down to the lower part. The thermoplastic resin material flows down while contacting the entire inner surface of the hopper (4) below the lower end of the inner cylinder (5). Therefore, roving cutter
Even if the fibers (L1) and (L1) introduced from (1) scatter on the inner wall surface of the hopper (4), the thermoplastic resin material flows down along the inner surface of the hopper (4) along the spiral track. The fibers (L1) (L1) are in a state of being washed away, whereby the fibers (L1) (L1)
Is stored in the lower part of the hopper (4) together with the thermoplastic resin material.

The speed of the conveyor (22) is determined by the number of revolutions of the motor (23) for driving the conveyor (22).
The input amount of the thermoplastic resin material per unit time is determined by the number of rotations per unit time in (23). In this embodiment, the input amount of the thermoplastic resin material is 5.1 kg / min.
Is set to In addition, a thermoplastic resin material and a modifier or other filler for improving the
(4) It may be supplied to the side. [About the injection machine (3)] The injection machine (3) as a plasticizing apparatus for melting a thermoplastic resin material and kneading it with a fiber is:
As shown in FIG. 4, it is basically the same as a known general screw type injection machine,
(31) retreats in the axial direction with rotation, but the area corresponding to the material receiving port (37) in the groove (38) always has a dimension satisfying the following expression during the retreat movement. Preferably, it is set.

That is, when the diameter d (cm) of the material receiving port (37) is the same as or larger than the groove width c (cm) of the screw (31), the screw including the flight is usually used.
Assuming that the outer diameter of (31) is a (cm) and the diameter of the groove bottom is b (cm), the dimension of the area corresponding to the material receiving port (37) in the groove (38) is:

[0031]

(Equation 3)

It is preferable to set the following. When the outer diameter a and the like are set so as to satisfy the above equation, it can be confirmed that the material smoothly penetrates the screw (31). The boundary between the root of the flight and the bottom of the groove is usually formed in an arc shape,
As the value of the groove diameter b in the above equation, the value of the smallest portion between flights is selected.

When the material receiving port (37) is smaller than the groove width c, the diameter d of the material receiving port (37) is substituted into the left side of the equation instead of the groove width c to satisfy the equation. Screw (3
What is necessary is just to set the outer diameter a and the groove diameter b of 1). In the case of an injection machine, since the screw (31) retreats in the axial direction with rotation, the groove (38) below the material receiving port (37) is used.
Also moves in the axial direction, but as described above, all the grooves (38) below the material receiving port (37) satisfy the above expression.

The specific dimensions of the screw diameter a, the groove diameter b, and the groove width c are, in this embodiment, screw diameter a = 1.
2cm, groove diameter b = 8.7cm, groove width c = 10.8cm
Therefore, in this case, the value on the right side of the above equation is set to 579 cm ³ . The diameter of the material receiving port (37) was set to 12 cm. In addition, injection machines
In the melting and kneading process in (3), a full flight screw is adopted as the screw (31) to suppress fiber cutting during the kneading process. A mixing head (32) having a check ring mechanism for preventing backflow to the upstream side is mounted. The screw (31) extends from its proximal end to its distal end in a feed zone (311), a compression zone (3
12) and a metering zone (313). The feed zone (31
1) Groove depth is 16.5mm, compression zone
The groove depth of (312) is set to a dimension that sequentially changes from 16.5 mm to 5.25 mm, and the groove depth of the metering zone (313) is set to 5.25 mm. The ratio of the distance between the feed zone (311), the compression zone (312) and the metering zone (313) of the screw (31) is set to 2: 1: 1. Also, screw (3
The flight pitch in 1) is set to 120 mm, and the groove width c is set to 10.8 cm as described above.

It is desirable that the compression ratio of the screw (31) is set to 4 or less and the apparent speed is set to 100 sec-1. Here, the compression ratio is given by the following equation. Compression ratio = groove depth of feed zone (311) / groove depth of metering zone (313) Also, apparent shear speed is given by the following equation.

Apparent shear rate = πDn / 60H, where D: diameter of screw (31) (mm) n: number of rotations of screw (31) (rpm) H: groove depth (mm) In the embodiment, a compression ratio of 3.14 is used. Further, the rotation speed of the screw (31) is set to 60 r. p. m, the apparent speed is 71.8 sec.
It was set to c-1.

The screw (31) is driven to rotate by a screw driving device (33) and reciprocates in the axial direction. [Regarding hopper (4)] Hopper (4) to be a material supply path
Injects the fiber fed from the roving cutter (1) and the thermoplastic resin material fed from the quantitative feeder (2) into an injection machine.
(3).

The material of the hopper (4) is not particularly limited, but it is preferable to use a material that does not easily generate static electricity. Further, if necessary, a static electricity removing device that blows static electricity removing air to a place where the fibers adhere due to static electricity may be provided. Furthermore, keeping the amount of fibers and thermoplastic resin material within the hopper (4) within a certain range leads to stability such as the time required to melt the thermoplastic resin material, and so on. Above hopper
On the side of (4), an upper proximity switch (41) and a lower proximity switch (42) located below the upper proximity switch (41) are provided. And
Proximity switch with lower storage of fiber and thermoplastic resin material
(42) When it becomes below, the operation of the roving cutter (1) and the fixed-quantity feeder (2) starts, and the fibers and the thermoplastic resin material start to be injected into the hopper (4), and the storage amount of these materials becomes (41). The roving cutter (1) and the quantitative feeder
The operation of (2) is stopped, and the specific control thereof will be described later.

Next, the inclination angle θ between the inner wall surface of the hopper (4) and the vertical line (see FIG. 4) will be described. Is preferably set to 45 ° or less, preferably 30 ° or less, and more preferably 15 ° or less. By setting such an angle, fibers and the like can be placed in the material receiving port (3
7) It was confirmed that it could be supplied smoothly to the side. Therefore, in the present embodiment in which the hopper (4) has a conical shape, the inclination angle θ is an angle formed by a generatrix of the cone and a vertical line, that is, a half vertex angle of the cone, and specifically, A hopper (4) having the inclination angle θ set to 10 ° was employed.

When the hopper (4) is not conical but has an elliptical or polygonal cross section, the inclination angle θ of the gentlest part of the gradient of the inner wall surface (gradient with respect to the horizontal). Must be set to be less than or equal to the value of. This is to prevent the adhesion of the fibers even in the region having the gentlest gradient. In this embodiment, the hopper (4)
Is a polyethylene terephthalate film (having a thickness of 0.1 mm).
4 mm) on the outer surface of stainless steel for reinforcement. The upper proximity switch (41) and the lower proximity switch (42) are arranged along the wall surface of the hopper (4) at an interval of 150 mm.

In this embodiment, in order to more reliably prevent fibers and the like from adhering to the inner wall surface of the hopper (4),
A vibration generator (43) is provided on the outer surface of the hopper (4) to vibrate the hopper (4). [Regarding the inner cylinder (5)] The inner cylinder (5) is disposed coaxially with the upper part of the hopper (4) and is formed in a conical shape, and the fibers are formed in the hopper (4). ) Has the function of guiding near the center. The material of the inner cylinder (5) is not particularly limited. However, in order to suppress the adhesion of the fibers (L1) and (L1), a material that does not easily generate static electricity as in the hopper (4) is desirable. The size of the fiber input port (51) and the fiber discharge port (52) at the upper and lower ends of the inner cylinder (5) may be the same, or any of them may be larger, as shown in the figure, When an inverted conical shape is used, the inclination angle θ ′ of the inner wall surface with respect to the vertical line is preferably set to 30 ° or less, and preferably 15 °.
° or less is good. When the angle is set to this angle, the effect of preventing adhesion of the fibers is remarkably exhibited.

The inner cylinder (5) used in this embodiment is
Polyethylene terephthalate film (0.4mm thickness)
And a fiber inlet (51) of the inner cylinder (5).
Is set to 65 mm, and the inclination angle θ ′ is set to 10 ° similarly to the hopper (4). Further, in the present embodiment, in order to more reliably prevent fibers from adhering to the inner surface of the inner cylinder (5), the thermoplastic resin material supplied from the fixed amount feeder (2) is supplied to the inner cylinder (5). The wall is vibrated by the collision (see FIG. 1).
Therefore, in this embodiment, the above-described mechanism for causing the thermoplastic resin material to collide with the inner cylinder (5) functions as a vibration generator that vibrates the inner cylinder (5).

Further, in order to more reliably prevent the fibers from adhering to the inner wall surface of the inner cylinder (5), a special vibration generator such as a vibrator for vibrating the inner cylinder (5) may be provided. good. [Regarding the molding operation] The above device is controlled by a control device which performs a control operation based on the flowchart shown in FIG. 5, and the control device includes (a) in FIG.
And a second computer that operates according to the flowchart in (b).

The operation of the above apparatus will be described with reference to the flowchart of FIG. Resin hopper for metering feeder (2) (21)
A thermoplastic resin material (for example, polypropylene resin) in the form of a pellet is charged into the apparatus, and the end of the long reinforcing fiber (L) drawn from the reel (19) is inserted between the feed rolls (11) and (11). Is operated, the first and second computers start operating.

When the first computer starts, the steps
In (ST1), the roving cutter (1) and the fixed-quantity feeder (2) are driven. The fixed-quantity feeder (2) and the roving cutter (1) may be driven at the same time.
The roving cutter (1) may be driven after driving the roving cutter (1), or conversely, the roving cutter (1) may be driven before driving the quantitative feeder (2). What is necessary is just to drive the above-mentioned fixed-quantity feeder (2) and the like at the timing when the fibers can be simultaneously supplied into the hopper (4).

The above roving cutter (1) and the fixed-quantity feeder
When (2) starts, the fibers (L1) and (L1) are formed by the operation of the roving cutter (1), and the fibers fall from the fiber discharge port (52) of the inner cylinder (5) into the hopper (4). On the other hand, the thermoplastic resin material (P) supplied from the fixed-quantity feeder (2)
After (6), it is thrown into the hopper (4) from its tip.
The thermoplastic resin material (P) charged from the chute (6)
In some cases, a part of the fiber (L1) collides with the inner cylinder (5) and vibrates it, along the inner wall surface of the hopper (4), and is fed from the inner cylinder (5). Flow down the hopper (4) while wrapping around (L1). Therefore, even if the fibers (L1) and (L1) charged into the flow-down area scatter toward the inner wall surface of the hopper (4), the heat is applied to the inner wall surface where the fibers (L1) and (L1) scatter. Since the thermoplastic resin material (P) flows down while contacting, the fibers (L1) (L1) are removed from the inner wall surface of the hopper (4) so as to be washed away by the thermoplastic resin material (P). Thereby, the fiber (L1) is formed on the inner surface of the hopper (4).
(L1) does not adhere in large quantities.

Next, when the storage amount of the thermoplastic resin material (P) and the like put into the hopper (4) increases and the upper surface thereof rises to the upper proximity switch (41), the upper proximity switch (41) is turned on. 41) outputs a detection signal, and the roving cutter (1) and the fixed-quantity feeder (2) are stopped by the detection signal (steps (ST2) and (ST3)). On the other hand, the upper proximity switch (4
When the detection signal is output from 1), the second computer executes steps (ST11) to (ST12) shown in FIG. 5B to drive the injection machine (3). That is, while the screw (31) is rotated by the screw driving device (33), the screw (31) is retracted in the axial direction, and a heater (not shown) attached to the outer surface of the cylinder (39) generates heat. Then, a thermoplastic resin material (P) or the like is supplied from the lower end of the hopper (4) into the cylinder (39) through the material receiving port (37), and is transferred to the tip side of the screw (31) and is also transferred. It is gradually heated and melted by the heater. Eventually, when the accumulated amount of the molten resin at the tip of the screw (31) reaches the set value, the rotation of the screw (31) is stopped (steps (ST13) and (ST14)),
Thereafter, the screw (31) is advanced in the axial direction at (33). Then, the mixing head (32) having the check ring mechanism discharges the molten resin from the discharge port (36) at the tip of the cylinder (39), and the molten resin is injected into a mold (not shown) to produce a molded product.

During the above operation, the storage amount of the thermoplastic resin material (P) in the hopper (4) is reduced by the lower proximity switch (42).
When it decreases below, the first computer executes the step (ST4) shown in FIG. 5A, and again operates the roving cutter (1) and the fixed-quantity feeder (2) in the step (ST1). As a result, the storage amount of the thermoplastic resin material (P) and the like in the hopper (4) is always maintained between the upper proximity switch (41) and the lower proximity switch (42).

In the above embodiment, the fibers are concentrated near the central axis of the hopper (4), and a large amount of the thermoplastic resin material exists around the fibers. Further, as described above, since the fibers (L1) and (L1) hardly adhere to the inner wall surface of the hopper (4), the mixing ratio of the thermoplastic resin material (P) and the fibers (L1) and (L1) is constant. Become. Therefore, the quality of the molded product is stabilized, and the time from when the thermoplastic resin material (P) is supplied to the injection machine (3) until it is melted is constant, and from this point, the quality of the molded product is also stabilized. .

When the polypropylene resin and the roving glass fiber described above are melt-mixed using the apparatus of the above embodiment to produce a fiber-reinforced resin molded product, the fiber length is cut from the roving cutter (1). 14mm fiber (L1) (L1)
Is charged into the inner cylinder (5) at a speed of 2.2 kg / min, and the resin pellets are fed from the quantitative feeder (2) to 5.1 kg / m.
It was thrown into the hopper (4) while hitting the inner cylinder (5) in. As a result, it took about 18 seconds to bring 2 kg of the glass fiber reinforced polypropylene resin into a molten state, but this time was always stable. Further, the weight of the molded article and the melting time were extremely stable. This means that the above-described first element having the above-described inclination angle θ set to the above value and the above-described groove portion
This shows that both elements of the second element which set (38) to dimensions satisfying the expression contribute to stabilization of the melting time and the like. If any of the first and second elements does not contribute to smooth movement of the material such as fiber, the material cannot be supplied at a constant flow rate to the downstream side of the screw (31). is there.

In the above embodiment, the hopper
(4) Injection machine smoothly without clogging of fiber and resin
Supplied to (3). In the above embodiment, although the value of the expression on the right side was used screw (31) which is set to 579cm ^3, it said value even with 350 cm ^3, the weight and the melting time of the molded article is stable I was [Other modified examples of each part] Regarding the charging of the thermoplastic resin material (P) In the above embodiment, the thermoplastic resin material (P) is applied from the fixed-quantity feeder (2) to the inner cylinder (5), but as shown in FIG. Roving cutter (1) with fixed-quantity feeder (2)
And the thermoplastic resin material (P) may be dropped into the gap between the inner cylinder (5) and the hopper (4) in a free-fall manner. In this case, the thermoplastic resin material for the hopper (4)
(P) resin input section is fiber (L1) (L1) fiber input section (inner cylinder
(5)). Even in this case, the fibers (L1) and (L1) are scattered in a region where the thermoplastic resin material (P) flows down while contacting the inner wall surface of the hopper (4).
The fibers (L1) (L1) are wrapped in the thermoplastic resin material (P). Therefore, fibers (L1) and (L1) are added to the hopper (4).
Even if adhered, it is removed so as to be washed away by the thermoplastic resin material (P). In this method, the chute (6) in FIG. 1 becomes unnecessary. . In the above embodiment, the fibers (L1) and (L1) cut by the roving cutter (1) were introduced.However, there is no problem if the fibers cut to a predetermined length can be introduced. As shown, a fixed-quantity feeder capable of quantitatively feeding a chopped strand cut in advance to a predetermined length may be used. . About hopper (4) As shown in FIG. 8, the fibers (L1) and (L1) and the thermoplastic resin material
A stirrer (8) for stirring (P) in the hopper (4) may be provided. The stirring device (8) has a motor (82) and a stirring blade (81) attached to a rotating shaft thereof. As shown in the figure, by stirring the fibers (L1) and (L1) and the thermoplastic resin material (P), the bulk specific gravity of the mixture can be increased. The effect of reducing the processing time and the like is obtained by reducing the entrapment of air.
When the hopper (4) is provided with the upper proximity switch (41) and the lower proximity switch (42), the stirring device (8) needs to be provided above the upper proximity switch (41). . In the above-described embodiment, an example in which the present invention is applied to an injection machine has been described as an example. However, the present invention can be applied to a case where the injection machine (3) is an extruder.

[Brief description of the drawings]

FIG. 1 is an overall view of an injection machine illustrating an embodiment of the present invention.

FIG. 2 shows the roving cutter (1) and the inner cylinder (5) in FIG.
Illustration of the relationship

FIG. 3 is a detailed view of the quantitative feeder (2) shown in FIG.

FIG. 4 is a view for explaining the inclination angles θ and θ ′ of the inner wall surfaces of the hopper (4) and the inner cylinder (5) in the injection machine of FIG. 1, and each zone of the screw (31).

FIG. 5 is a flowchart illustrating a control operation of the injection machine in FIG. 1;

FIG. 6: Quantitative feeder above roving cutter (1)
Diagram for explaining a modification in which (2) is provided

FIG. 7 is a view for explaining a modification in which (7) is used instead of the roving cutter (1).

FIG. 8 is a view for explaining an example in which a stirrer (8) is provided.

FIG. 9 is a sectional view taken along the line IX-IX in FIG. 1;

[Explanation of symbols]

 (1) ... roving cutter (2) ... fixed-quantity feeder (3) ... injection machine (4) ... hopper (5) ... inner cylinder (31) ... screw (37) ..Material receiving port (38) ・ ・ ・ Groove (P) ・ ・ ・ Thermoplastic resin material

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 7, 2001 (2001.11.
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Patent application title: Method for feeding fiber and thermoplastic resin material to plasticizing device and plasticizing device

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of supplying fibers and a thermoplastic resin material to a plasticizing apparatus and a plasticizing apparatus, and is applied to, for example, an injection machine for molding a molded article made of fiber reinforced resin. can do.

[0002]

2. Description of the Related Art Conventionally, when a molded article made of a fiber reinforced resin is injection-molded, a thermoplastic resin material is melted and kneaded with the fiber by an extruder as a plasticizing device. A fiber-reinforced resin pellet in which the reinforcing fiber is contained in the resin is produced, supplied to the injection machine, melted and kneaded again, and then supplied into the mold, and thereafter, the fiber-reinforced resin in the mold is supplied. There is known one which is cooled and cured to form a molded article.

As an injection molding apparatus having an extruder for kneading a fiber and a thermoplastic resin, Japanese Patent Application Laid-Open No. 4-28 is disclosed.
The one disclosed in No. 6617 is known. In this apparatus, a thermoplastic resin supply port and a fiber supply port on the downstream side thereof are provided in a cylinder of an extruder, and the cylinder is provided with a thermoplastic resin material supplied from the thermoplastic resin supply port. The fiber fed from the fiber supply port is added to the heated and melted resin while heating, and the fiber is melted and kneaded on the downstream side. Then, injection molding is performed using the fiber reinforced resin obtained as described above.

According to this method, a molded article made of a fiber-reinforced resin can be formed only by supplying fibers from a fiber supply port provided in a cylinder of an extruder. There is an advantage that the injection molding can be performed by substantially the same operation as the molding. However, in this case, it is necessary to separately provide a thermoplastic resin supply port and a fiber supply port in the cylinder of the extruder, and to ensure that the fibers from near the fiber supply port bite into the screw in the cylinder smoothly. Therefore, there is a drawback that a screw design such as making the screw a deep groove is required.

As another apparatus for injection molding a molded article made of fiber reinforced resin, the invention of Japanese Patent Application Laid-Open No. 2-153714 has been proposed. In this method, the thermoplastic resin material and the fiber are directly supplied to a cylinder of an injection machine as a plasticizing device. However, even in this case, it is necessary to separately form a thermoplastic resin supply port and a fiber supply port in the cylinder. It is necessary to provide a pushing device for pushing the fibers into the cylinder at the fiber supply port.

An invention disclosed in Japanese Patent Application Laid-Open No. 6-8278 discloses an invention for eliminating the above-mentioned disadvantages of the conventional injection molding apparatuses. This is to supply the thermoplastic resin material and the fiber together to the injection machine through a single material supply path.

[0007]

However, this method has the following problems. . The fibers adhere to the inner wall surface of the hopper as the material supply path due to static electricity or the like, and there is a concern that the material supply path may be clogged due to the fibers. In particular, when long fibers are used in order to lengthen the fibers remaining in the final molded product, the clogging is liable to occur because the bulk specific gravity becomes small.

[0008] The fiber mass that adheres and grows on the inner wall surface of the material supply path collectively enters an extruder or an injection machine, and the mixing ratio of the fiber and the thermoplastic resin material becomes unstable. Therefore, when a molded article made of fiber reinforced resin is produced using this technique, the quality of the molded article cannot be stabilized.
Further, when the mixing ratio is unstable, the time from supply to an injection machine or the like until the thermoplastic resin material is melted is not constant. Since the quality changes, it is not possible to stabilize the quality of the molded product from this point.

[0009] The present invention has been made in view of such a point, and even when supplying a long fiber having a small bulk specific gravity,
It is an object of the present invention to prevent clogging of a material supply path and to stabilize a mixing ratio of a fiber and a thermoplastic resin material.

[0010]

The technical means of the first aspect of the present invention for solving the above-mentioned problem is that "the fiber and the thermoplastic resin material are fed into a common material supply path and both are plasticized at the same time. A method of supplying the material to the apparatus, wherein the material supply path is constituted by a double cylinder of an outer cylinder and an inner cylinder disposed coaxially in an upper part of the outer cylinder, between the inner cylinder and the outer cylinder. While feeding a granular or powdery thermoplastic resin material, a fiber having an average fiber length of 3 mm to 50 mm is charged into the inner cylinder, and the fiber is wrapped in the outer cylinder downstream from the lower end of the inner cylinder. The thermoplastic resin material is supplied to the plasticizer. "

According to the above technical means, the fibers introduced into the inner cylinder flow down the material supply passage so as to be wrapped in the granular or powdery thermoplastic resin material in the material supply passage. Therefore, even if fibers are likely to adhere to the inner wall surface of the material supply passage, the fibers move downstream together with the resin material so as to be washed away by the thermoplastic resin material. That is, the fibers are removed so as to be washed away by the thermoplastic resin material, and the fibers do not accumulate in the material supply path. Further, since the thermoplastic resin material comes into contact with the inner wall surface of the material supply path and the fiber is injected into the inside thereof, the fiber is located at the center side in the material supply path.

According to the second aspect of the present invention, in which the wall surface of the material supply path is vibrated, it is possible to more reliably prevent fibers from adhering to the inner wall surface of the material supply path. Further, the density of the mixed fiber and the thermoplastic resin material is increased by the vibration. Like the invention of claim 3,
When the plasticizing device is an injection machine or an extruder, and the downstream end of the material supply path is connectable to a material receiving port (37) of the injection machine or the extruder, the fibers and the thermoplastic resin are used. The method of supplying the material to the plasticizing device can be effectively used for an injection machine or an extruder.

According to a fourth aspect of the present invention, there is provided a plasticizing apparatus having a common material supply path into which fibers and a thermoplastic resin material are charged, wherein the material supply path is coaxial with an outer cylinder and an upper portion in the outer cylinder. A resin injection means for inputting a granular or powdery thermoplastic resin material between the inner cylinder and the outer cylinder, and a mean fiber in the inner cylinder. 3m long
a fiber feeding means for feeding fibers of m to 50 mm, and the resin feeding means and the fibers so that the fibers are fed into the inner cylinder at a timing when the thermoplastic resin material is fed into the material supply path. And a control device for activating the charging means. "
An apparatus for plasticizing a fiber and a thermoplastic resin material according to the present invention can be provided.

According to a fifth aspect of the present invention, "the resin supply section in the material supply path in the resin supply means is the same as the fiber supply section in the material supply path in the fiber supply means. It is more preferable that the resin input section and the fiber input section are arranged vertically.

[0015] In the invention of claim 4 or claim 5,
In the invention according to claim 6, wherein "the vibration generating device for vibrating the wall surface of the material supply path" is provided, by vibrating the wall surface of the material supply path, the adhesion of the fiber to the material supply path is more reliably performed. Can be prevented. In addition, the density of the fiber and the thermoplastic resin material in the material supply path increases due to the vibration.

According to a fourth aspect of the present invention, in the seventh aspect of the invention, there is provided a vibration generating device for vibrating at least one of the inner cylinder and the material supply path. By vibrating at least one of these, it is possible to reliably prevent fibers from adhering to these wall surfaces. The invention according to any one of claims 4 to 7, wherein the plasticizer is an injection machine or an extruder, and a downstream end of the material supply path is connected to a material receiving port (37) of the injection machine or the extruder. It is also possible to adopt a configuration as described in the eighth aspect of the present invention.

The fiber input means, which is a specific matter of the invention according to the fourth aspect, may be a roving cutter (1) or a fixed-quantity feeder for supplying the fibers quantitatively as in the ninth aspect of the invention. Various feeding devices can be used.

[0018]

As described above, according to the first aspect of the present invention, the fibers introduced into the inner cylinder flow down in the material supply path so as to be wrapped in the thermoplastic resin material in the material supply path. Therefore, the fibers do not adhere to the wall surface of the material supply path, and the material supply path is not clogged even when a long fiber having a low bulk specific gravity is supplied.

Further, since the fibers do not adhere to and remain on the inner wall of the material supply passage, the ratio of the fibers to the thermoplastic resin material can be stabilized. Therefore, when a molded article made of fiber reinforced resin is produced using the invention of claim 1, a molded article of good quality in which the mixing ratio of the fiber and the thermoplastic resin material is stable is obtained. Claim 2
According to the second aspect of the present invention, the vibration of the wall surface of the material supply path can more reliably prevent the fiber from adhering to the inner wall surface of the material supply path, so that the effect of the first aspect becomes more remarkable.
Also, due to the vibration of the wall surface of the material supply path, the density of the mixed fiber and the thermoplastic resin material increases, so when this mixture is supplied to a plasticizing device such as an injection machine or an extruder and heated and kneaded, The time required for the thermoplastic resin material to melt is stabilized.

According to the fourth aspect of the present invention, it is possible to provide a plasticizing apparatus for implementing the first aspect of the present invention. Since the fibers are supplied into the inner cylinder surrounded by the outer cylinder, the fear that the fibers adhere to the outer cylinder as the material supply path is further reduced, and the inner cylinder and the like are vibrated. Adhesion can be more reliably prevented.

[0021]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a screw-type injection machine (3) as a plasticizing device for fibers and a thermoplastic resin material according to the embodiment of the present invention.

In this apparatus, a roving cutter (1) for quantitatively supplying fibers is used as the fiber input means, and a resin input means for inputting a thermoplastic resin material upstream of the fiber input section. As a quantitative feeder (2)
Is used. However, the fiber feeding means is not limited to the roving cutter (1), but may be a quantitative feeder for quantitatively chopped strand fibers cut in advance to a predetermined length. Also, the resin charging means is not limited to the above-described quantitative feeder (2) as long as it can supply the thermoplastic resin material quantitatively.

The lower end of the hopper (4) is connected to a material receiving port (37) formed in the upper wall near the upstream end of the cylinder (39) of the injection machine (3). Is the material supply path described above. In the upper part of the hopper (4),
An inner cylinder (5) for feeding fibers is provided.
(4) and the inner cylinder (5) are arranged coaxially to form a double cylinder. Therefore, in this embodiment, the hopper (4) corresponds to the outer cylinder as the invention specifying matter of the first aspect of the present invention.

A roving cutter (1) is provided above the inner cylinder (5) so that fibers cut to a predetermined length are introduced into the inner cylinder (5). . The thermoplastic resin material is fed from the hopper (4) and the inner cylinder (5) through the chute (6) inclined at an angle that allows the thermoplastic resin material to flow naturally from the fixed-quantity feeder (2). It has become.
In this embodiment, the injection machine (3) is provided at the lower end of the hopper (4).
However, a screw type extruder or the like for melting the thermoplastic resin material and kneading the fiber with the thermoplastic resin material may be connected.

Hereinafter, each part of the apparatus will be described in more detail. [About roving cutter (1)] Roving cutter
(1) As shown in FIGS. 1 and 2, a feed roll (11) for feeding a large number of long reinforcing fibers (L) (L) wound up on a reel (19) in a flattened state. (11) and a cutting roll (12) provided on the outlet side thereof and longer than the transfer width of the long reinforcing fibers (L) (L), wherein the cutting roll (12) is a lower feed roll. It is provided with a plurality of blades (121) (121) that are in rotation with respect to (11). Therefore, the blade (121) (121) and the feed roll (11)
According to (11), the long reinforcing fiber (L) is a fixed length fiber (L1) (L
Cut to 1).

Further, the cutting roll (12) is adapted to rotate clockwise in FIG. 1, whereby the fibers (L1) and (L1) surely fall into the inner cylinder (5). It is configured as follows. In this embodiment, a long reinforcing fiber
Four 2400 tex roving glass fibers as (L) are fed to feed rolls (11) and (11), whereby fibers (L1) and (L1) having a length of 14 mm are obtained. The fibers (L1) (L1) from the roving cutter (1)
The drop amount in 1) is set to 2.2 kg / min.

The cutting length of the long reinforcing fiber (L) by the cutting roll (12) is determined by the length of the cutting roll (12).
Is determined by the pitch of the blade (121) (121)
The length of the fiber (L1) (L1) formed by the cutting is 3 mm
It can be set in the range of ５０50 mm. fiber
(L1) It was confirmed that even when the length of (L1) was set in the above range, it could be smoothly supplied to the downstream side by the hopper (4) and the screw (31). The fibers actually cut (L1) (L
1) Since the length has some errors, the length is 3 mm to 50 mm.
mm may slightly exceed the range, but it is sufficient that the average fiber length falls within the range. [About the fixed-quantity feeder (2)] A fixed-quantity feeder as a resin charging means for charging the thermoplastic resin material to the hopper (4).
(2) As shown in FIG. 3, a resin hopper (21) for storing a thermoplastic resin material in the form of a pellet, and the resin hopper (21)
And a conveyor (22) for quantitatively supplying the thermoplastic resin material from the chute to the chute (6).
The downstream end of (6) penetrates into the hopper (4) and extends to near the outer wall of the inner cylinder (5) (see FIG. 1). Therefore, the hopper
(4) Chute serving as resin input part of thermoplastic resin material
The tip of (6) is located upstream of the lower end of the inner cylinder (5), which is the fiber feeding section. The tip of the chute (4)
It may be at the same height position as the lower end of the inner cylinder (5).

The method of attaching the chute (6) to the hopper (4) is not particularly limited, but as shown in FIG.
The center axis of (6) is slightly offset from the center axis of hopper (4), and the direction of the granular or powdery thermoplastic resin material injected from chute (6) is
It is preferable not to intersect with the central axis. In this case, the thermoplastic resin material input from the chute (6) falls down while sliding in the circumferential direction on the inner wall surface of the hopper (4). Spirally wrapping the hopper (4)
It is easy to flow down to the lower part. The thermoplastic resin material flows down while contacting the entire inner surface of the hopper (4) below the lower end of the inner cylinder (5). Therefore, roving cutter
Even if the fibers (L1) and (L1) introduced from (1) scatter on the inner wall surface of the hopper (4), the thermoplastic resin material flows down along the inner surface of the hopper (4) along the spiral track. The fibers (L1) (L1) are in a state of being washed away, whereby the fibers (L1) (L1)
Is stored in the lower part of the hopper (4) together with the thermoplastic resin material.

The speed of the conveyor (22) is determined by the number of revolutions of the motor (23) for driving the conveyor (22).
The input amount of the thermoplastic resin material per unit time is determined by the number of rotations per unit time in (23). In this embodiment, the input amount of the thermoplastic resin material is 5.1 kg / min.
Is set to In addition, a thermoplastic resin material and a modifier or other filler for improving the
(4) It may be supplied to the side. [Regarding the injection machine (3)] The injection machine (3) for melting the thermoplastic resin material and kneading the fiber with the thermoplastic resin material, as shown in FIG.
This is basically the same as a known general screw-type injection machine, and as described later, the screw (31) retreats in the axial direction with rotation, but receives material in the groove (38). The area corresponding to the mouth (37) is preferably set to a dimension that satisfies the following expression at all times during the backward movement.

That is, when the diameter d (cm) of the material receiving port (37) is the same as or larger than the groove width c (cm) of the screw (31), the screw including the flight is usually used.
Assuming that the outer diameter of (31) is a (cm) and the diameter of the groove bottom is b (cm), the dimension of the area corresponding to the material receiving port (37) in the groove (38) is:

[0031]

(Equation 1)

It is preferable to set the following. When the outer diameter a and the like are set so as to satisfy the above equation, it can be confirmed that the material smoothly penetrates the screw (31). The boundary between the root of the flight and the bottom of the groove is usually formed in an arc shape,
As the value of the groove diameter b in the above equation, the value of the smallest portion between flights is selected.

When the material receiving port (37) is smaller than the groove width c, the diameter d of the material receiving port (37) is substituted into the left side of the equation instead of the groove width c to satisfy the equation. Screw (3
What is necessary is just to set the outer diameter a and the groove diameter b of 1). In the case of an injection machine, since the screw (31) retreats in the axial direction with rotation, the groove (38) below the material receiving port (37) is used.
Also moves in the axial direction, but as described above, all the grooves (38) below the material receiving port (37) satisfy the above expression.

The specific dimensions of the screw diameter a, the groove diameter b, and the groove width c are, in this embodiment, screw diameter a = 1.
2cm, groove diameter b = 8.7cm, groove width c = 10.8cm
Therefore, in this case, the value on the right side of the above equation is set to 579 cm ³ . The diameter of the material receiving port (37) was set to 12 cm. In addition, injection machines
In the melting and kneading process in (3), a full flight screw is adopted as the screw (31) to suppress fiber cutting during the kneading process. A mixing head (32) having a check ring mechanism for preventing backflow to the upstream side is mounted. The screw (31) extends from its proximal end to its distal end in a feed zone (311), a compression zone (3
12) and a metering zone (313). The feed zone (31
1) Groove depth is 16.5mm, compression zone
The groove depth of (312) is set to a dimension that sequentially changes from 16.5 mm to 5.25 mm, and the groove depth of the metering zone (313) is set to 5.25 mm. The ratio of the distance between the feed zone (311), the compression zone (312) and the metering zone (313) of the screw (31) is set to 2: 1: 1. Also, screw (3
The flight pitch in 1) is set to 120 mm, and the groove width c is set to 10.8 cm as described above.

It is desirable that the compression ratio of the screw (31) is set to 4 or less and the apparent speed is set to 100 sec-1. Here, the compression ratio is given by the following equation. Compression ratio = groove depth of feed zone (311) / groove depth of metering zone (313) Also, apparent shear speed is given by the following equation.

Apparent shear rate = πDn / 60H, where D: diameter of screw (31) (mm) n: number of rotations of screw (31) (rpm) H: groove depth (mm) In the embodiment, a compression ratio of 3.14 is used. Further, the rotation speed of the screw (31) is set to 60 r. p. m, the apparent speed is 71.8 sec.
It was set to c-1.

The screw (31) is driven to rotate by a screw driving device (33) and reciprocates in the axial direction. [Regarding hopper (4)] Hopper (4) to be a material supply path
Injects the fiber fed from the roving cutter (1) and the thermoplastic resin material fed from the quantitative feeder (2) into an injection machine.
(3).

The material of the hopper (4) is not particularly limited, but it is preferable to use a material that does not easily generate static electricity. Further, if necessary, a static electricity removing device that blows static electricity removing air to a place where the fibers adhere due to static electricity may be provided. Furthermore, keeping the amount of fibers and thermoplastic resin material within the hopper (4) within a certain range leads to stability such as the time required to melt the thermoplastic resin material, and so on. Above hopper
On the side of (4), an upper proximity switch (41) and a lower proximity switch (42) located below the upper proximity switch (41) are provided. And
Proximity switch with lower storage of fiber and thermoplastic resin material
(42) When it becomes below, the operation of the roving cutter (1) and the fixed-quantity feeder (2) starts, and the fibers and the thermoplastic resin material start to be injected into the hopper (4), and the storage amount of these materials becomes (41). The roving cutter (1) and the quantitative feeder
The operation of (2) is stopped, and the specific control thereof will be described later.

Next, the inclination angle θ between the inner wall surface of the hopper (4) and the vertical line (see FIG. 4) will be described. Is preferably set to 45 ° or less, preferably 30 ° or less, and more preferably 15 ° or less. By setting such an angle, fibers and the like can be placed in the material receiving port (3
7) It was confirmed that it could be supplied smoothly to the side. Therefore, in the present embodiment in which the hopper (4) has a conical shape, the inclination angle θ is an angle formed by a generatrix of the cone and a vertical line, that is, a half vertex angle of the cone, and specifically, A hopper (4) having the inclination angle θ set to 10 ° was employed.

When the hopper (4) is not conical but has an elliptical or polygonal cross section, the inclination angle θ of the gentlest part of the gradient of the inner wall surface (gradient with respect to the horizontal). Must be set to be less than or equal to the value of. This is to prevent the adhesion of the fibers even in the region having the gentlest gradient. In this embodiment, the hopper (4)
Is a polyethylene terephthalate film (having a thickness of 0.1 mm).
4 mm) on the outer surface of stainless steel for reinforcement. The upper proximity switch (41) and the lower proximity switch (42) are arranged along the wall surface of the hopper (4) at an interval of 150 mm.

In this embodiment, in order to more reliably prevent fibers and the like from adhering to the inner wall surface of the hopper (4),
A vibration generator (43) is provided on the outer surface of the hopper (4) to vibrate the hopper (4). [Regarding the inner cylinder (5)] The inner cylinder (5) is disposed coaxially with the upper part of the hopper (4) and is formed in a conical shape, and the fibers are formed in the hopper (4). ) Has the function of guiding near the center. The material of the inner cylinder (5) is not particularly limited. However, in order to suppress the adhesion of the fibers (L1) and (L1), a material that does not easily generate static electricity as in the hopper (4) is desirable. The size of the fiber input port (51) and the fiber discharge port (52) at the upper and lower ends of the inner cylinder (5) may be the same, or any of them may be larger, as shown in the figure, When an inverted conical shape is used, the inclination angle θ ′ of the inner wall surface with respect to the vertical line is preferably set to 30 ° or less, and preferably 15 °.
° or less is good. When the angle is set to this angle, the effect of preventing adhesion of the fibers is remarkably exhibited.

The inner cylinder (5) used in this embodiment is
Polyethylene terephthalate film (0.4mm thickness)
And a fiber inlet (51) of the inner cylinder (5).
Is set to 65 mm, and the inclination angle θ ′ is set to 10 ° similarly to the hopper (4). Further, in the present embodiment, in order to more reliably prevent fibers from adhering to the inner surface of the inner cylinder (5), the thermoplastic resin material supplied from the fixed amount feeder (2) is supplied to the inner cylinder (5). The wall is vibrated by the collision (see FIG. 1).
Therefore, in this embodiment, the above-described mechanism for causing the thermoplastic resin material to collide with the inner cylinder (5) functions as a vibration generator that vibrates the inner cylinder (5).

Further, in order to more reliably prevent the fibers from adhering to the inner wall surface of the inner cylinder (5), a special vibration generator such as a vibrator for vibrating the inner cylinder (5) may be provided. good. [Regarding the molding operation] The above device is controlled by a control device which performs a control operation based on the flowchart shown in FIG. 5, and the control device includes (a) in FIG.
And a second computer that operates according to the flowchart in (b).

The operation of the above apparatus will be described with reference to the flowchart of FIG. Resin hopper for metering feeder (2) (21)
A thermoplastic resin material (for example, polypropylene resin) in the form of a pellet is charged into the apparatus, and the end of the long reinforcing fiber (L) drawn from the reel (19) is inserted between the feed rolls (11) and (11). Is operated, the first and second computers start operating.

When the first computer starts, the steps
In (ST1), the roving cutter (1) and the fixed-quantity feeder (2) are driven. The fixed-quantity feeder (2) and the roving cutter (1) may be driven at the same time.
The roving cutter (1) may be driven after driving the roving cutter (1), or conversely, the roving cutter (1) may be driven before driving the quantitative feeder (2). What is necessary is just to drive the above-mentioned fixed-quantity feeder (2) and the like at the timing at which the fibers can be simultaneously supplied into the hopper (4).

The above roving cutter (1) and the fixed-quantity feeder
When (2) starts, the fibers (L1) and (L1) are formed by the operation of the roving cutter (1), and the fibers fall from the fiber discharge port (52) of the inner cylinder (5) into the hopper (4). On the other hand, the thermoplastic resin material (P) supplied from the fixed-quantity feeder (2)
After (6), it is thrown into the hopper (4) from its tip.
The thermoplastic resin material (P) charged from the chute (6)
In some cases, a part of the fiber (L1) collides with the inner cylinder (5) and vibrates it, along the inner wall surface of the hopper (4), and is fed from the inner cylinder (5). Flow down the hopper (4) while wrapping around (L1). Therefore, even if the fibers (L1) and (L1) charged into the flow-down area scatter toward the inner wall surface of the hopper (4), the heat is applied to the inner wall surface where the fibers (L1) and (L1) scatter. Since the thermoplastic resin material (P) flows down while contacting, the fibers (L1) (L1) are removed from the inner wall surface of the hopper (4) so as to be washed away by the thermoplastic resin material (P). Thereby, the fiber (L1) is formed on the inner surface of the hopper (4).
(L1) does not adhere in large quantities.

Next, when the storage amount of the thermoplastic resin material (P) and the like put into the hopper (4) increases and the upper surface thereof rises to the upper proximity switch (41), the upper proximity switch (41) is turned on. 41) outputs a detection signal, and the roving cutter (1) and the fixed-quantity feeder (2) are stopped by the detection signal (steps (ST2) and (ST3)). On the other hand, the upper proximity switch (4
When the detection signal is output from 1), the second computer executes steps (ST11) to (ST12) shown in (b) of FIG. 5 to drive the injection machine (3). That is, while the screw (31) is rotated by the screw driving device (33), the screw (31) is retracted in the axial direction, and a heater (not shown) attached to the outer surface of the cylinder (39) generates heat. Then, a thermoplastic resin material (P) or the like is supplied from the lower end of the hopper (4) into the cylinder (39) through the material receiving port (37), and is transferred to the tip side of the screw (31) and is also transferred. It is gradually heated and melted by the heater. Eventually, when the accumulated amount of the molten resin at the tip of the screw (31) reaches the set value, the rotation of the screw (31) is stopped (steps (ST13) and (ST14)),
Thereafter, the screw (31) is advanced in the axial direction at (33). Then, the mixing head (32) having the check ring mechanism discharges the molten resin from the discharge port (36) at the tip of the cylinder (39), and the molten resin is injected into a mold (not shown) to produce a molded product.

During the above operation, the storage amount of the thermoplastic resin material (P) in the hopper (4) is reduced by the lower proximity switch (42).
When it decreases below, the first computer executes the step (ST4) shown in FIG. 5A, and again operates the roving cutter (1) and the fixed-quantity feeder (2) in the step (ST1). As a result, the storage amount of the thermoplastic resin material (P) and the like in the hopper (4) is always maintained between the upper proximity switch (41) and the lower proximity switch (42).

In the above embodiment, the fibers are concentrated near the central axis of the hopper (4), and a large amount of the thermoplastic resin material exists around the fibers. Further, as described above, since the fibers (L1) and (L1) hardly adhere to the inner wall surface of the hopper (4), the mixing ratio of the thermoplastic resin material (P) and the fibers (L1) and (L1) is constant. Become. Therefore, the quality of the molded product is stabilized, and the time from when the thermoplastic resin material (P) is supplied to the injection machine (3) until it is melted is constant, and from this point, the quality of the molded product is also stabilized. .

When the polypropylene resin and the roving glass fiber described above are melt-mixed using the apparatus of the above embodiment to produce a fiber-reinforced resin molded product, the fiber length is cut from the roving cutter (1). 14mm fiber (L1) (L1)
Is charged into the inner cylinder (5) at a speed of 2.2 kg / min, and the resin pellets are fed from the quantitative feeder (2) to 5.1 kg / m.
It was thrown into the hopper (4) while hitting the inner cylinder (5) in. As a result, it took about 18 seconds to bring 2 kg of the glass fiber reinforced polypropylene resin into a molten state, but this time was always stable. Further, the weight of the molded article and the melting time were extremely stable. This means that the above-described first element having the above-described inclination angle θ set to the above value and the above-described groove portion
This shows that both elements of the second element which set (38) to dimensions satisfying the expression contribute to stabilization of the melting time and the like. If any of the first and second elements does not contribute to smooth movement of the material such as fiber, the material cannot be supplied at a constant flow rate to the downstream side of the screw (31). is there.

In the above embodiment, the hopper
(4) Injection machine smoothly without clogging of fiber and resin
Supplied to (3). In the above embodiment, although the value of the expression on the right side was used screw (31) which is set to 579cm ^3, it said value even with 350 cm ^3, the weight and the melting time of the molded article is stable I was [Other modified examples of each part] Regarding the charging of the thermoplastic resin material (P) In the above embodiment, the thermoplastic resin material (P) is applied from the fixed-quantity feeder (2) to the inner cylinder (5), but as shown in FIG. Roving cutter (1) with fixed-quantity feeder (2)
And the thermoplastic resin material (P) may be dropped into the gap between the inner cylinder (5) and the hopper (4) in a free-fall manner. In this case, the thermoplastic resin material for the hopper (4)
(P) resin input section is fiber (L1) (L1) fiber input section (inner cylinder
(5)). Even in this case, the fibers (L1) and (L1) are scattered in a region where the thermoplastic resin material (P) flows down while contacting the inner wall surface of the hopper (4).
The fibers (L1) (L1) are wrapped in the thermoplastic resin material (P). Therefore, fibers (L1) and (L1) are added to the hopper (4).
Even if adhered, it is removed so as to be washed away by the thermoplastic resin material (P). In this method, the chute (6) in FIG. 1 becomes unnecessary. . In the above embodiment, the fibers (L1) and (L1) cut by the roving cutter (1) were introduced.However, there is no problem if the fibers cut to a predetermined length can be introduced. As shown, a fixed-quantity feeder capable of quantitatively feeding a chopped strand cut in advance to a predetermined length may be used. . About hopper (4) As shown in FIG. 8, the fibers (L1) and (L1) and the thermoplastic resin material
A stirrer (8) for stirring (P) in the hopper (4) may be provided. The stirring device (8) has a motor (82) and a stirring blade (81) attached to a rotating shaft thereof. As shown in the figure, by stirring the fibers (L1) and (L1) and the thermoplastic resin material (P), the bulk specific gravity of the mixture can be increased. The effect of reducing the processing time and the like is obtained by reducing the entrapment of air.
When the hopper (4) is provided with the upper proximity switch (41) and the lower proximity switch (42), the stirring device (8) needs to be provided above the upper proximity switch (41). . In the above-described embodiment, an example in which the present invention is applied to an injection machine has been described as an example. However, the present invention can be applied to a case where the injection machine (3) is an extruder.

[Brief description of the drawings]

FIG. 1 is an overall view of an injection machine illustrating an embodiment of the present invention.

FIG. 2 shows the roving cutter (1) and the inner cylinder (5) in FIG.
Illustration of the relationship

FIG. 3 is a detailed view of the quantitative feeder (2) shown in FIG.

FIG. 4 is a view for explaining the inclination angles θ and θ ′ of the inner wall surfaces of the hopper (4) and the inner cylinder (5) in the injection machine of FIG. 1, and each zone of the screw (31).

FIG. 5 is a flowchart illustrating a control operation of the injection machine in FIG. 1;

FIG. 6: Quantitative feeder above roving cutter (1)
Diagram for explaining a modification in which (2) is provided

FIG. 7 is a view for explaining a modification in which (7) is used instead of the roving cutter (1).

FIG. 8 is a view for explaining an example in which a stirrer (8) is provided.

FIG. 9 is a sectional view taken along the line IX-IX in FIG. 1;

[Description of Signs] (1) ・ ・ ・ Roving cutter (2) ・ ・ ・ Quantitative feeder (3) ・ ・ ・ Injection machine (4) ・ ・ ・ Hopper (5) ・ ・ ・ Inner cylinder (31) ・ ・ ・Screw (37) ・ ・ ・ Material receiving port (38) ・ ・ ・ Groove (P) ・ ・ ・ Thermoplastic resin material

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeyoshi Matsubara 2-10-1, Tsukahara, Takatsuki-shi, Osaka Sumitomo Kagaku Kogyo Co., Ltd. F-term (reference) 4F201 AB25 AC01 AC04 AL09 AL10 AL13 BA01 BA06 BC37 BD04 BD05 BK59 BK74 BQ02 BQ08 BQ32 BQ40 BQ57 4F206 AB25 AC01 AC04 AR12 JA07 JD03 JF01 JF02 JF11 JF12 JF22 JF23 JL02 JM01 JN01 JQ02 JQ11

Claims (13)

[Claims] 1. A method in which a fiber and a thermoplastic resin material are supplied to a common material supply path and both are supplied to a plasticizing device at the same time, wherein the material supply path is provided on an outer cylinder and an upper part in the outer cylinder. The inner fiber is constituted by a double cylinder of an inner cylinder disposed coaxially, and while the granular or powdery thermoplastic resin material is charged between the inner cylinder and the outer cylinder, the average fiber length is 3 mm in the inner cylinder. A method of feeding a thermoplastic resin material to a plasticizer and feeding the thermoplastic resin material so as to wrap the fiber in an outer cylinder downstream of the lower end of the inner cylinder by feeding fibers of about 50 mm. 2. The method according to claim 1, wherein the wall surface of the material supply path is vibrated. 3. The plasticizing device is an injection machine or an extruder, and a downstream end of the material supply path is connectable to a material receiving port (37) of the injection machine or the extruder. 2. A method for supplying the fibers and the thermoplastic resin material to the plasticizing device. 4. An external diameter of a material transfer screw (31) provided in said injection machine or said extruder is a,
Assuming that the diameter of the groove bottom of the groove (38) of (31) is b and the groove width of the groove (38) is c, under the condition that the size of c is equal to or smaller than the diameter of the material receiving port (37). In the groove (38), the material receiving port (37)
The area corresponding to is The method for supplying a fiber and a thermoplastic resin material to a plasticizing apparatus according to claim 3, which satisfies the following. 5. The fiber according to claim 4, wherein the diameter of the material receiving port (37) is larger than the diameter of the material receiving port (37). A method for supplying a thermoplastic resin material to a plasticizing device. 6. An apparatus for supplying a fiber and a thermoplastic resin material to a plasticizing device, comprising a common material supply path into which the fiber and the thermoplastic resin material are introduced, wherein the outer cylinder and an upper part in the outer cylinder are provided. A material supply path configured by a double cylinder of coaxially disposed inner cylinders; a resin injection unit that inputs a granular or powdery thermoplastic resin material between the inner cylinder and the outer cylinder; A fiber feeding means for feeding fibers having an average fiber length of 3 mm to 50 mm into the inner cylinder, and a timing at which the thermoplastic resin material is injected into the material supply path so that the fibers are injected into the inner cylinder. And a controller for operating the fiber charging means and the fiber charging means. 7. A resin supply section in the material supply path in the resin supply means is provided above a fiber supply section in the material supply path in the fiber supply means. A feeding device for feeding a fiber and a thermoplastic resin material to a plasticizing device. 8. The apparatus for supplying a fiber and a thermoplastic resin material to a plasticizing apparatus according to claim 6, further comprising a vibration generator for vibrating a wall surface of said material supply path. 9. The apparatus according to claim 6, further comprising a vibration generator for vibrating at least one of the inner cylinder and the outer cylinder. 10. The plasticizer according to claim 6, wherein the plasticizer is an injection machine or an extruder, and a downstream end of the material supply path is connectable to a material receiving port (37) of the injection machine or the extruder. 9. A supply device for supplying any one of the fibers and the thermoplastic resin material to a plasticizing device. 11. The outer diameter of a material transfer screw (31) provided in the injection machine or the extruder is a, the diameter of the groove bottom of the groove (38) of the screw (31) is b, and the groove is Assuming that the groove width of (38) is c, under the condition that c is equal to or less than the diameter of the material receiving port (37), the material receiving port (37) in the groove (38) )
The area corresponding to 11. A supply device for supplying a fiber and a thermoplastic resin material to a plasticizing device according to claim 10, which satisfies the following. 12. The fiber according to claim 11, wherein the diameter of the material receiving port (37) is larger than the diameter of the material receiving port (37). Supply device for thermoplastic resin material to plasticizer. 13. The fiber-to-thermoplastic resin material according to claim 6, wherein said fiber feeding means is a roving cutter (1) or a fixed-quantity feeder for feeding said fiber quantitatively. Supply device to the gasifier.