JPH09150436A - Injection method and injection apparatus for executing this method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a state where a molten resin and a reinforcing fiber are distributed to some extent at the time point when the mixture is fed into a screw part by mixing the reinforcing fiber into the molten resin outside of a screw type injection machine and feeding this molten reinforcing fiber contg. thermoplastic resin compsn. into the upstream end part of the screw part of the injection machine. SOLUTION: When an apparatus is started and a thermoplastic resin is fed into a melt extruder 1 and a molten resin is started to be extruded from an outlet 11, a roving cutter is started and reinforcing fibers L1 and L1 are mixed into a falling-down region from the outlet 11. In addition, a screw type injection machine 2 is started to operate simultaneously and the molten resin fed into a feeder 21 is transferred to the front end side by means of a screw 22. During this transformation, kneading of the reinforcing fiber and the molten resin is accelerated. When the amt. of the transferred molten resin increases, the molten resin is stored on the front end side of the screw 22 and the screw 22 is retreated. When the amt. of storing reaches a set value, the screw 22 is pushed in the axial line direction and the stored resin is injected into a mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for injecting a reinforced fiber-containing thermoplastic resin composition into a molding section using a screw type injection machine, and an injection apparatus for carrying out the method.

[0002]

2. Description of the Related Art Conventionally, when a fiber reinforced resin is injection-molded, a conventional screw-type injection molding machine is used to mold a product using a fiber reinforced resin pellet containing a reinforced fiber material in a thermoplastic synthetic resin. There is. In this method, the fiber-reinforced resin pellets are melted in the injection molding machine, the molten resin and the reinforcing fibers are kneaded by the screw, and stored at the tip of the screw. When the stored amount reaches the set amount, the molten resin is injected into the mold attached to the injection molding machine.

According to this method, there is an advantage that a fiber-reinforced resin product can be injection-molded in the same manner as injection-molding with a normal resin containing no reinforcing fiber. However, in this method, the fiber component in the resin pellet is easily cut when it is kneaded with the molten resin by the screw, the length of the fiber contained in the injection-molded fiber-reinforced resin product is short, and the degree of reinforcement by this fiber is Was insufficient. In particular, in the case of a fiber reinforced resin product such as a control panel, which requires a large mechanical strength, the insufficient strength due to the insufficient reinforcement is a serious problem. In the case of products such as the control panel, in order to secure the required strength, the fiber length is as long as possible,
Moreover, the reinforcing fibers need to be uniformly dispersed and mixed in the product, which is far from this in the case of the product by the conventional method.

As an improvement of the above-mentioned conventional method, a method in which a reinforcing fiber material and a resin pellet are simultaneously charged into a screw type injection machine (Japanese Patent Laid-Open No. 6-8278), and a reinforcing fiber is contained in a molten resin in the injection machine. There is proposed a method for charging (JP-A-2-153714, JP-A-4-286617). However, in the former method, the fiber length becomes very short, and in the latter method, although the reinforcing fiber after molding becomes somewhat long, it is still not sufficient, and there is also a problem that the dispersibility is poor, Neither of these methods was able to satisfy both the fiber length and dispersibility. In addition, the latter method has a problem that the filling rate of the reinforcing fibers in the obtained product varies.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above points, and relates to "a method for injecting a reinforced fiber-containing thermoplastic resin composition into a molding part by using a screw type injection machine". In addition to making it possible to increase the length of the reinforcing fiber dispersed in the molded fiber-reinforced resin product,
An object of the present invention is to improve the mechanical strength such as bending strength and impact strength of a fiber reinforced resin product by making the degree of dispersion of these reinforcing fibers good.

[0006]

[Means for Solving the Problems] According to the means of the invention of claim 1 for solving the above-mentioned problems, "Mixed reinforcing fibers are mixed with molten resin outside a screw type injection machine to contain the molten reinforcing fibers. The thermoplastic resin composition was introduced into the upstream end of the screw part of the injection machine. " The said means operate as follows.

[0007] Since the molten resin and the reinforcing fiber are mixed into the screw type injection machine in advance, the molten resin and the reinforcing fiber are distributed to some extent at the time of being charged into the screw section. Therefore, the dispersion of the reinforcing fibers is better than that in the conventional method in which the reinforcing fibers are directly added to the molten resin in the screw part. Further, the dispersion ratio of the resin component and the reinforcing fiber component is kept constant.

Further, since plasticization in the screw part is not required, the shearing rate for melt-kneading can be set low, and the chance of cutting the reinforcing fiber in the screw part is reduced. It is not necessary that all of the reinforcing fibers be mixed in the molten resin, and some of the reinforcing fibers may be mixed by kneading in the injection molding machine. According to a second aspect of the present invention, "the molten resin discharged from the discharge port of the melt extruder for extruding the molten resin is made to flow down into the upstream end portion of the screw portion of the screw type injector, and the predetermined length is set. The reinforced fibers that have been cut into are mixed in the molten resin feeding path. ”In this, the reinforced fibers are distributed in the molten resin feeding path, that is, in the path that hangs down from the discharge port. Since the mixed fibers are mixed, it is difficult for the reinforced fibers to be subjected to an unreasonable external force for kneading during the distribution and mixing, so that the reinforcing fibers are hard to be cut before being fed into the injection molding machine.

According to the invention of claim 3, "the screw of the screw type injection machine is a full flight screw, the compression ratio by this screw is 4 or less, and the apparent shear rate is 100 sec ^-1 or less". , Cutting of the reinforcing fiber in the screw part is less than that of a normal screw. According to the fourth aspect of the present invention, in which "the reinforcing fibers are mixed in the vicinity of the discharge port of the melt extruder", the melted resin flowing down from the discharge port to the injection molding machine is used. Since the contact length with the reinforcing fiber is maximized, the distribution and mixing of the reinforcing fiber in this flow-down path is promoted.

According to a fifth aspect of the present invention, "in the flow-down area of the molten resin discharged from the discharge port, a planar flow-down area where the molten resin faces each other is provided, and the planar flow-down melting is performed. Including the step of pressurizing the resins to each other in a close contact state from the side and introducing the reinforcing fibers from the upper side thereof '', the reinforcing fibers are forcibly distributed and mixed into the planar molten resin facing each other. This distribution and mixing effect is further promoted.

According to a sixth aspect of the present invention, "a cutter for cutting a long reinforcing fiber into a certain length is provided, and the cutting reinforcing fiber distributed and discharged from this cutter is mixed with the molten resin". In this case, even relatively long fibers that have been conventionally mixed can be stably distributed and supplied, and the reinforcing fibers that are cut into a certain length and are distributed and dropped as they are are uniformly distributed to the molten resin.

[0012] The invention of claim 7 is an invention of an injection molding apparatus for carrying out the invention of claim 1, "a melt extruder for extruding a molten resin, and a reinforcing fiber cut into a predetermined length. And a screw type injection machine equipped with a molten resin injection port in which reinforcing fibers are distributed and mixed, and the reinforcing fibers falling from the reinforcing fiber distribution and supply device are melted. It is configured such that it is mixed in the open space with respect to the molten resin that is extruded from the discharge port of the extruder and flows down to the input port of the screw type injection machine ”. With this, the method according to claim 1 can be easily and surely implemented.

[0013]

According to the invention of claim 1, the chances of cutting the reinforcing fiber at the screw portion are reduced, the ratio of the resin component and the reinforcing fiber component is kept constant, and the dispersion of the reinforcing fiber is uniform. Therefore, the mechanical strength such as bending strength and shear strength of the fiber reinforced resin product is improved.

According to the second aspect of the invention, the effect of the first aspect, in particular, the effect of increasing the length of the reinforcing fiber in the fiber-reinforced resin product is further improved. According to the invention of claim 3, the number of breakage of the reinforcing fiber in the screw portion is smaller than that of the normal screw, so that the effect of claim 2 is further improved. According to the invention of claim 4, in the invention of claim 2 or 3, the homogenization of the dispersion of the reinforcing fibers is further promoted.

According to the invention of claim 5, since the reinforcing fibers are forcibly distributed and mixed, the distribution and mixing effect is further promoted. According to claim 6, the effects of the inventions of claims 2 to 5 are further improved. According to the invention of claim 7, the method of claim 1 described above can be carried out easily and surely.

[0016]

Next, embodiments of the present invention will be described in detail with reference to the drawings. As an apparatus for carrying out the method of the present invention, an apparatus having a structure as shown in FIG. 1 is used. This device has the following configuration. Melt extruder (1)
The molten resin extruded from the screw type injection machine (2)
Input from the resin input port (21). A long reinforcing fiber (L) is provided above the vicinity of the molten resin discharge port (11) of the melt extruder (1).
A roving cutter (3) is provided for cutting the reinforcing fibers (L ₁ ) (L ₁ ) of a certain length. And the reinforcing fiber (L ₁ )
The roving so that the dropping path of (L ₁ ) is discharged from the discharge port (11) and flows down so that the molten resin hangs down (hereinafter, simply referred to as a downflow path) is joined. The position of the cutter (3) is set.

The respective parts of the apparatus will be described in detail below. [About the melt extruder (1)] The melt extruder (1) is a heating cylinder.
A screw feeder (12) is provided in (10), and a thermoplastic resin in the form of pellets or powder is charged from a supply port (13) opened above the base end of the screw feeder (12). It

The screw feeder (12) is rotated by a rotation driving device (121) and the thermoplastic resin charged from a supply port (13) is provided with a discharge port (1) provided at a tip of a melt extruder (1).
Send to 1). During this time, the thermoplastic resin is heated by the heating cylinder (10).
And the heat generated by the shearing action of the screw feeder (12). The discharge port (11) is
As shown in Fig. 2, it is set in a flat rectangular shape that is long in the horizontal direction, and the discharge amount per unit time from the discharge port (11) of this cross-sectional shape is determined by the rotation speed of the screw feeder (12). It The total discharge amount is determined by the total rotation amount of the screw feeder (12).

A shutoff valve (16) is inserted between the discharge port (11) and the screw feeder (12), and the shutoff valve (16) is opened when the molten resin is discharged. Therefore, it is closed when the discharge of the molten resin is stopped. Furthermore, the discharge port (11) and a screw type injection machine
A cylindrical protective tube (14) is placed between the resin inlet (21) in (2).
Is provided, a funnel-shaped insertion port portion (15) is formed at the upper end of the protection cylinder (14), and the roving cutter (3) is arranged above the insertion port portion (15). The size of the cross section of the protective cylinder (14) is set to be larger than the cross section of the molten resin discharged from the discharge port (11), and the molten resin and the inner surface of the protective cylinder (14) contact each other. do not do. [About the roving cutter (3)] The roving cutter (3) is made up of many long reinforcing fibers wound on a reel.
(L) Feed roll (3
1) (31) and the long reinforcing fiber (L) provided on the outlet side thereof
(L) consisting of a cutting roll (32) longer than the transfer width, the cutting roll (32) is provided with a plurality of blades in contact with the lower feed roll (31) in a rotating state, the blade The long reinforcing fibers (L) are cut into the reinforcing fibers (L ₁ ) (L ₁ ) having a constant length by the and the feed roll (31). Therefore, in the range corresponding to the transfer width of the long reinforcing fibers (L) (L) by the feed rolls (31) (31) (a slightly wider range than the transfer width), the reinforcing fibers (L ₁ ) ( L ₁ ) disperses and falls.

The arrangement position and rotation direction of the cutting roll (32) are set so that the falling direction of the reinforcing fibers (L ₁ ) (L ₁ ) is directed to the charging port (15). .
Further, the falling range of the reinforcing fibers (L ₁ ) (L ₁ ) and the width of the molten resin (61) discharged from the discharge port (11) and flowing down are substantially matched. In addition, the cutting length by the cutting roll (32) is determined by the arrangement pitch of the blades implanted in the cutting roll (32), and the length of the reinforcing fiber (L ₁ ) is 3 mm to 2 mm.
It is set to 0 mm.

In this embodiment, as the long reinforcing fibers (L), nine roving glass fibers of 1100 tex are fed between the feed rolls (31) and (31) and cut into a fiber length of 15 mm. . Further, the amount of the reinforcing fibers (L ₁ ) (L ₁ ) falling from the cutting roll (32) is set to 3 Kg / min. [Screw-type injection machine (2)] The screw-type injection machine (2) is basically the same as a well-known general screw-type injection molding machine, but it is usually a hopper provided for feeding materials. Has been changed to the above-mentioned resin charging port (21).

Further, a full flight screw is adopted as the screw (22) in the screw type injection machine (2),
A mixing head (24) having a check ring mechanism is attached to the tip. The screw (22) is
From its end to the tip, feed zone (221), compression zone (222), metering zone (223)
It is divided into 3 zones in this order. The feed zone (221) has a groove depth of 32.8 mm, and the compression zone (222) has a groove depth of 328 mm to 19.
With a taper to 3 mm, the groove depth of the metering zone (223) is set to 19.3 mm and the ratio of the respective zone lengths is set to 2: 1: 1.

The compression ratio of this screw (22) is 4
The following is preferably set to 3 or less, and particularly preferably set to 2 or less, and the apparent shear rate is 100 sec.
^-1 or less, preferably 50 sec ^-1 is set. Here, the compression ratio is given by the following expression: compression ratio = groove depth of fize zone / groove depth of metalling zone Further, the apparent shear rate is given by the following expression.

Apparent shear rate = πDn / 60H where D: diameter of screw (22) (mm) n: number of rotations of screw (22) (rpm), H: groove depth (m
m) The screw (22) is rotationally driven by the screw driving device (25) and is reciprocally moved in the axial direction.

[Molded Resin Pushing Device] In the screw type injection machine (2) of this embodiment, the forming portion of the charging port (21) in the barrel (20), that is, the base end of the screw (22), As shown in FIG. 3 or 4, in order to allow the molten resin to be injected into the screw type injection machine (2), it is reciprocally driven by the reciprocating drive source (40) and the tip thereof is screw (22). The push rod (4) is set to have a shape (arc shape) that contacts the surface of the. Push bar (4)
The tip end of is aligned with one of both ends of the surface of the screw (22) in the direction of rotation with respect to the peripheral edge of the input port (21).

Therefore, when the molten resin was charged into the rotating screw (22) from the charging port (21) and reciprocated by the reciprocating drive source (40), it was collected on the surface of the screw (22). The molten resin is forcibly pushed into the groove of the screw (22) through the charging port (21). Also, the screw (2
The enlarged hole (231) is formed in the hole (23) for accommodating 2), and the expanded hole (231) is screwed in the cross section of the hole (23).
The surface of (22) is formed within a certain range from the entering side (hereinafter referred to as the biting side (211)). The enlarged hole (2
The cross sectional shape of 31) is set so as to bulge outward with respect to the cross section of the hole (23). Further, the cross-sectional shape of the enlarged hole portion (231) in the axial direction of the screw (22) is set to an arc shape.

Therefore, the molten resin pushed into the groove portion of the screw (22) by the pushing rod (4) is smoothly moved to the biting side (211), and the enlarged hole portion (2
It is pushed into the inside of 31), and then the molten resin is transferred to the tip side of the screw (22) by the rotation of the screw (22). Also, particularly in the case of FIG. 3, the pushing rod (4)
The molten resin pushed by is the biting side (211)
Smoothly pushed into the enlarged hole (231) from
The rotation of the screw (22) causes the molten resin to
Transferred to the tip side of 2).

The edge of the cross section of the enlarged hole portion (231) reaches the peripheral edge of the charging port (21). Further, the reciprocating driving device (40) may be configured to vibratably drive the pushing rod (4) back and forth. [Injection Molding Operation] Each of the above-described devices is controlled by a computer-type control device that executes a control operation based on the flowchart shown in FIG.

Fiber-reinforced resin by the device of the above embodiment
Explain the actual molding process based on the above flowchart
I do. When the above equipment is started, the melt extruder (1) is heated.
Plastic resin (for example, polyprorylene resin) is added,
Roving when molten resin begins to be discharged from the discharge port (11)
The cutter (3) will start and the molten resin will flow from the discharge port (11).
Reinforcing fiber (L₁) (L ₁) Is mixed. (Step 8
1) In the case of this embodiment, this polypropylene resin and glass
In the case of spun fiber, glass is supplied at the above-mentioned supply rate of 10 kg / min.
The fiber filling rate is 30 WT%.

At the same time, the operation of the screw type injection machine (2) is started, and the screw drive device (25) and the reciprocating drive source (40) are brought into a driving state. As a result, the molten resin charged into the charging port (21) is transferred to the tip side by the screw (22). During this transfer, the kneading of the reinforcing fibers and the molten resin is further promoted. In addition, since the compression ratio at this time is set to 4 or less and the apparent shear rate is set to 100 sec ^-1 , the degree of cutting of the reinforcing fiber is less than that of the conventional one.

When the amount of the molten resin transferred by the screw (22) increases, the molten resin is stored on the tip side of the screw (22), and the screw (2
2) retreats. When the stored amount reaches a set amount determined by the relationship with the resin amount of the fiber reinforced resin product, the rotation by the screw driving device (25) is stopped (step 82), and then the screw driving device (25) rotates the screw. (22) is pushed out in the axial direction, and the stored resin is injected into the molding die. (Step 83) At the same time when the rotation of the screw (22) is stopped, the rotation driving device (1
The rotation of 21) is stopped and the operation of the roving cutter (3) is stopped. Therefore, with the screw (22) stopped,
The operation of charging the mixture of the molten resin and the reinforcing fiber into the charging port (21) is stopped.

In general, in the melt extruder (1), even if the rotation of the screw feeder (12) is stopped, it is difficult to immediately stop the operation of discharging the molten resin from the discharge port (11). Therefore, in the above embodiment, as shown in FIG.
A shutter (5) is installed in the protective cylinder (14) to block the flow of molten resin, and is synchronized with the shut-off valve (16) provided near the upstream side of the discharge port (11) of the melt extruder (1). I try to activate it.

Therefore, when the molten resin is charged, the shutoff valve (16) and the shutter (5) are opened (steps 80 and 84), and the shutoff valve (16) and the shutter (5) are stopped when the screw (22) is stopped. ) Is closed (step 821). Therefore, it is possible to eliminate the inconvenience that extra molten resin is added when the screw (22) is stopped.

After the injection operation is completed after the molten resin injection operation and the screw (22) is returned to the initial position, the shut-off valve (16) and the shutter (5) are opened to perform the above-mentioned series of operations. Will be repeated.
The discharge port (11) of the melt extruder (1) of the above-mentioned embodiment is set to a flat rectangular shape, and is discharged from the falling range of the reinforcing fibers (L ₁ ) (L ₁ ) and the discharge port (11). Since the width of the molten resin is almost the same as that of the molten resin, the reinforcing fiber (L ₁ ) (L
₁ ) will be evenly distributed. Therefore, the dispersion of the reinforcing fibers in the fiber-reinforced resin product molded by the above series of operations becomes uniform.

Incidentally, as in the above embodiment, a fiber reinforced resin product of polypropylene resin and glass fiber is manufactured, the feed rate is 10 Kg / min, and the groove depth of the feed zone (221) of the screw (22) is set. The compression zone 222 has a groove depth of 328 mm to 19.28 mm.
A full flight screw with a taper to 3 mm and a groove depth of the metalling zone (223) set to 19.3 mm was adopted, the compression ratio was 1.7, and the apparent shear rate was 50 sec.
^When molded under the conditions set to ^-1 , the average reinforcing fiber length in the fiber reinforced resin product was 3.5 mm or more, and the degree of dispersion of this reinforcing fiber was also good. In this case, the average reinforcing fiber length is longer than that of the conventional method described above, and the dispersibility is significantly improved. [Other modified examples of each part] Regarding the melt extruder (1) In the above embodiment, the molten resin is supplied to the screw type injection machine (2) by the melt extruder (1), but when it is desired to make the molten resin supply rate extremely uniform. Is shown in FIG.
As shown in (1), an accumulator (7) may be attached to the tip of the melt extruder (discharge port (11)), and the molten resin may be supplied to the screw type injector (2) through the accumulator.

In this case, the melt extruder (1) continuously operates regardless of the operation of the screw type injection machine (2), and the molten resin continuously extruded from the melt extruder (1) is It is stored in the accumulator (7). When a certain amount of molten resin is stored in the accumulator (7), the accumulator
By advancing the piston (71) of (7), it is melted and extruded from the accumulator discharge port (72) to the screw type injection machine (2) extremely quantitatively.

When the molten resin is started to be discharged from the accumulator discharge port (72), the roving cutter (3) is actuated, and the reinforcing fiber (L ₁ ) (L ₁ ) (L) flows from the molten resin accumulator discharge port (72) to the downstream area. ₁ ) is mixed. The subsequent operation is similar to that of the above-mentioned embodiment. . Regarding the mixing of the reinforcing fiber into the molten resin In the above embodiment, the reinforcing fiber (L ₁ ) (L ₁ ) falling from the roving cutter (3) is discharged to the molten resin discharged from the discharge port (11). Although the reinforcing fibers were mixed in the molten resin by direct distribution, the pre-cut reinforcing fibers (L ₁ ) (L ₁ ) group may be distributed to the upper part of the flow path of the molten resin using a vibrating feeder. .

Whether the reinforcing fibers (L ₁ ) (L ₁ ) cut by the roving cutter (3) are directly distributed or a vibrating feeder is used, the reinforcing fibers to the molten resin are
For distribution and mixing of (L ₁ ) and (L ₁ ), the method of FIGS. 6 and 7 or the method of FIGS. 8 and 9 may be adopted. In the method of FIGS. 6 and 7, a nozzle (6) is connected to the discharge port (11) of the melt extruder (1) and the molten resin is discharged downward from this nozzle (6) in a cylindrical shape. Then, drop the reinforcing fiber (L ₁ ) (L ₁ ) group from the roving cutter (3) or the vibrating feeder into the nozzle (6), and put the reinforcing fiber (L ₁ ) into the cylindrical molten resin (61). ₁ ) (L
_This is a method in which ₁ ) is charged into the charging port (21) in a distributed manner.

In this method, as shown in FIG. 12, before the cylindrical molten resin in which the reinforcing fibers (L ₁ ) (L ₁ ) are distributed is fed to the screw type injection machine (2), Even if it is crushed lightly by a pair of rolls (90) (90) provided in front of the molten resin injection port and rotated synchronously by individual drive rollers (92) (92), it is supplied to the screw type injection machine (2). Good. At this time, the tubular molten resin may be cut by the cutters (91) (91) every time the molten resin flows down for a predetermined length.

In this case, reinforcing fibers for the molten resin
The degree of distribution of (L ₁ ) and (L ₁ ) is further improved. In this case, since the reinforcing fibers (L ₁ ) (L ₁ ) are wrapped in the molten resin and are distributed to the charging port (21), the screw (( ₁ ) is charged into the charging port (21). Between the feed zone (221) of 22) and the metering zone (223) of the reinforcing fiber (L ₁ ) (L
_{This is because 1} ) is sufficiently and uniformly dispersed.

In particular, in the case of adopting the step of pressing the surface-like molten resins facing each other by the rolls (90) (90) so as to lightly crush them from the side, the reinforcing fiber (L ₁ ) is applied by the pressing step. (L ₁ ) is more surely dispersed and mixed. This also applies to the case where the molten resin flows down in the form of a pair of strip-shaped portions facing each other. 8 and 9
In this method, the molten resin is discharged and flowed downward from the nozzle (6) attached to the discharge port (11) of the melt extruder (1) in the form of a band of a certain width, and the cross-sectional shape of the protective cylinder (14) was melted as described above. A rectangular cross-section similar to the cross-sectional shape of the resin, and a lateral width chute that matches the flow-down width of the molten resin on the side of the flat surface of the flow-down molten resin.
(141) is provided on one side of the protection tube (14), and
In this method, the reinforcing fibers (L ₁ ) and (L ₁ ) are distributed and mixed into the molten resin (61) via the (141). In this case, it is easy to control the thickness of the belt-shaped molten resin to be supplied, and there is an advantage in that the area of the belt-shaped molten resin can be changed depending on the amount of the reinforcing fibers supplied.

In the method of FIG. 10, instead of the method of FIGS. 6 and 7, the molten resin (61) is made to flow from the nozzle (6) into a large number of rods or lines. In this case, the adhesion area of the reinforcing fibers (L ₁ ) (L ₁ ) to the molten resin (61) becomes large, so that the uniform distribution of the molten resin is further improved. . In the above embodiment, the shutter (5) is protected by the protective cylinder (14).
Although it is provided in the middle of the above, it may be provided in the vicinity of the discharge port (11) on the upstream side, and in the case where the nozzle (6) is provided as described above, it may be provided in this nozzle (6).

The thermoplastic resin applied to the method of the present invention is a general thermoplastic resin such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, ABS resin, polyacrylonitrile, polyamide, polycarbonate and polyethylene terephthalate. And mixtures thereof, polyphenylene ether resin / polyamide resin / compatibilizer, polyphenylene ether resin / GPPS
Resins, polymer alloys such as polyphenylene ether resin / impact-resistant polystyrene resin, and various thermoplastic elastomers are included, and these are usually compounded with additives such as heat stabilizers, UV inhibitors, colorants, and fillers. Various compounding agents described above may be compounded.

The fibers applied to the method of the present invention include those usually used as a reinforcing material for thermoplastic resins such as glass fibers and carbon fibers.

[Brief description of the drawings]

1 is an overall view of an apparatus for carrying out the method of the present invention.

FIG. 2 is a front view showing the relationship between the discharge port (11) of the melt extruder (1) and the roving cutter (3).

[Fig. 3] Detailed view of the relationship between the screw (22) and the push rod (4) at the inlet (21).

FIG. 4 is an explanatory view of another example of the enlarged hole portion (231).

FIG. 5 is a flowchart of the control device of the above embodiment.

FIG. 6 is an explanatory view of a nozzle (6) which is continuously provided to a discharge port (11).

FIG. 7: Relationship between cross section of molten resin (61) and reinforcing fibers (L ₁ ) (L ₁ ).

FIG. 8 is an explanatory view of another example of the nozzle (6).

FIG. 9 is a sectional view of the molten resin (61) in this case.

FIG. 10 is an explanatory view of another example of the nozzle (6).

FIG. 11 is an explanatory view of a case where molten resin is supplied to the screw type injection machine (2) through the accumulator (7).

FIG. 12 is an explanatory diagram of a case where a cylindrical molten resin is lightly crushed by a roll (90) and supplied to a screw type injection machine (2).

[Explanation of symbols]

(1) ・ ・ ・ Melt extruder (11) ・ ・ ・ Discharge port (2) ・ ・ ・ Screw injection machine (21) ・ ・ ・ Input port (22) ・ ・ ・ Screw (3) ・ ・ ・ Roving cutter ( L ₁ ) ... Reinforcing fiber

Claims (7)

[Claims] 1. A method of injecting a reinforcing fiber-containing thermoplastic resin composition into a molding part using a screw type injection machine, wherein reinforcing fiber is mixed with molten resin outside the screw type injection machine, An injection method in which a molten reinforcing fiber-containing thermoplastic resin composition is added to the upstream end of the screw part of an injection machine. 2. A molten resin discharged from a discharge port of a melt extruder for extruding the molten resin is made to flow down into an upstream end of a screw portion of a screw type injection machine, and cut into a predetermined length. The injection method according to claim 1, wherein reinforcing fibers are mixed in the injection path of the molten resin. 3. A screw of a screw type injection machine is a full flight screw, the compression ratio by this screw is 4 or less, and the apparent shear rate is 100 sec.
The injection method according to claim 1 or 2, which is ^-1 or less. 4. The injection method according to claim 2, wherein reinforcing fibers are mixed in the vicinity of the discharge port of the melt extruder. 5. A flow-down area of the molten resin discharged from the discharge port is provided with a planar flow-down area where the molten resins face each other, and the planar flow-down molten resin is brought into a close contact state laterally. The injection method according to any one of claims 2 to 4, including a step of applying pressure from above and introducing the reinforcing fiber into the pressing section from above. 6. The cutter according to claim 2, wherein a cutter for cutting the long reinforcing fiber into a certain length is provided, and the cut reinforcing fiber distributed and discharged from the cutter is mixed with the molten resin. Injection method. 7. A melt extruder for extruding a molten resin,
The reinforcing fiber distributing and supplying device for distributing and dropping the reinforcing fibers cut into a predetermined length, and the screw type injection machine having the inlet for the molten resin in which the reinforcing fibers are distributed and mixed are provided. An injection device configured such that reinforcing fibers falling from the device are extruded from the discharge port of the melt extruder and mixed in the open space with the molten resin flowing down to the input port of the screw type injection machine.