JP6933951B2 - Fiber reinforced thermoplastic resin kneading method and plasticizing equipment - Google Patents

Description

In the present invention, a fiber-reinforced thermoplastic resin is made from a thermoplastic resin and reinforcing fibers such as carbon fibers and glass fibers by using a plasticizing device having a cylinder and a screw such as an injection device of an injection molding machine and an extruder. It relates to a kneading method to obtain and a plasticizing device.

Molded products molded from fiber-reinforced thermoplastic resins composed of reinforcing fibers such as carbon fibers and glass fibers and thermoplastic resins have high strength and are used in various fields. The fiber-reinforced thermoplastic resin is obtained by kneading with a plasticizing device equipped with a screw such as an injection device of an injection molding machine and an extruder. For example, in order to obtain a fiber-reinforced thermoplastic resin by an extruder, resin pellets, which are materials for the thermoplastic resin, are supplied from a hopper. The resin pellets melt in the cylinder of the extruder and are fed forward by the screw. Reinforcing fibers are supplied into the cylinder at a predetermined position in the cylinder. Reinforcing fibers are provided as so-called rovings. That is, reinforcing fibers such as carbon fibers and glass fibers are made by bundling tens to hundreds of single fibers into strands, and dozens of such strands are twisted into a coarse thread. Such roving is supplied to the cylinder as it is. Alternatively, it is cut to a predetermined length and supplied to the cylinder. Then, the molten resin and the reinforcing fibers are kneaded by the rotation of the screw, and the reinforcing fibers are dispersed apart and appropriately cut to obtain a fiber-reinforced thermoplastic resin. When extruded from a predetermined die provided at the tip of the extruder, a massive intermediate molded product is obtained. When this is conveyed to a compression die and compression molded, a molded product made of a fiber-reinforced thermoplastic resin can be obtained.

Japanese Unexamined Patent Publication No. 2016-64607

Patent Document 1 describes a method of opening and supplying a reinforcing fiber provided as roving when a fiber-reinforced thermoplastic resin is produced from a thermoplastic resin and a reinforcing fiber. According to this document, "spreading" is a process of continuously thinning a bundle of reinforcing fibers into a wide and thin state. It is carried out by applying a high-pressure air flow, vibrating it by ultrasonic vibration to disperse it, or by using a fiber-spreading device equipped with a fiber-spreading roller. In other words, physical force is applied to disperse the reinforcing fibers that are restrained from each other in the roving state. In the method described in Patent Document 1, after the reinforcing fiber is opened in this way, the reinforcing fiber is cut to a predetermined length to obtain a cut reinforcing fiber. Then, for example, in the case of an injection molding machine, the cut reinforcing fibers are supplied to the heating cylinder of the injection device. Then, the molten resin and the reinforcing fiber are kneaded in the heating cylinder to obtain a fiber-reinforced thermoplastic resin. In the conventional method in which the reinforcing fibers are charged into the heating cylinder in the state of a bundle of reinforcing fibers without opening, the external force acting on the reinforcing fibers during kneading with the resin becomes non-uniform between the outside and the inside of the bundle, and the reinforcing fibers are broken. Although it is easy to cut, if the reinforcing fibers opened by the method described in Patent Document 1 are supplied and kneaded with the resin, the external force acting on the reinforcing fibers becomes uniform, so that it becomes difficult to cut. As a result, a fiber-reinforced thermoplastic resin having a uniform fiber length distribution can be obtained.

The fiber-reinforced thermoplastic resin can be obtained by kneading the fiber-reinforced thermoplastic resin by a conventional method or by the method described in Patent Document 1 by a plasticizing device provided with a screw. Then, this can be directly injected into a mold that has been molded, or extruded to obtain a massive intermediate molded product, which is carried into a molding mold and compression molded to obtain a molded product. However, there are some points that need to be resolved or improvements. The fiber-reinforced thermoplastic resin is required to have two points: that the reinforcing fibers are uniformly dispersed in the resin and that many reinforcing fibers having an appropriate fiber length remain. This is because if the dispersion of the reinforcing fibers is not uniform, a portion having weak strength is generated in the molded product, and if the number of reinforcing fibers having an appropriate fiber length is small, high strength cannot be obtained. However, these two requirements are in a trade-off relationship. Kneading of the resin and the reinforcing fibers is carried out by rotating the screw. For example, in order to improve the dispersibility of the reinforcing fibers, a screw having a large shearing force is used, or the reinforcing fibers are supplied from the upstream of the cylinder for comparison. It is necessary to knead for a long time. In this way, not only the dispersibility of the reinforcing fibers is increased, but also the impregnation of the reinforcing fibers with the resin is promoted. However, the reinforcing fibers are cut and the proportion of the reinforcing fibers having an appropriate fiber length is reduced, so that the strength of the molded product cannot be sufficiently obtained. On the other hand, in order to leave a large number of reinforcing fibers with an appropriate fiber length, the shape of the screw is devised to reduce the shearing force during kneading, or the reinforcing fibers are supplied from the downstream of the cylinder to shorten the kneading time. It should be time. However, when kneaded in this way, the dispersion of the reinforcing fibers becomes insufficient, and the strength is not uniformly developed in the obtained molded product. Neither the conventional method nor the method described in Patent Document 1 can satisfy these antinomy requirements at the same time. For the time being, the method described in Patent Document 1 is such that the reinforcing fibers provided as roving are opened, supplied to the resin and kneaded, so that the method is compared with the case where the reinforcing fibers are bundled. As a result, the external force acting on the reinforcing fibers during kneading with the resin becomes uniform, and the cutting of the reinforcing fibers can be suppressed to some extent. Cutting of reinforcing fibers is inevitable. That is, it is not possible to simultaneously satisfy the two requirements that are in a trade-off relationship.

Therefore, according to the present invention, when a thermoplastic resin and a reinforcing fiber such as a carbon fiber or a glass fiber are mixed and kneaded to obtain a fiber-reinforced thermoplastic resin, the dispersibility of the reinforcing fiber is enhanced and the reinforcing fiber having an appropriate fiber length is obtained. It is an object of the present invention to provide a method for kneading a fiber-reinforced thermoplastic resin so that sufficient amount of the resin remains, and a plasticizing apparatus for carrying out such a kneading method.

In the present invention, a plasticizer including a cylinder and a screw inserted in the cylinder supplies a thermoplastic resin and a reinforcing fiber to the cylinder and rotates the screw to obtain a fiber-reinforced thermoplastic resin. The method is targeted. The present invention is configured so that when the reinforcing fibers are supplied into the cylinder, they are supplied from a plurality of different locations in the cylinder. In addition, the plasticizer makes the clearance between the bore and screw of the cylinder larger from the predetermined cylinder position on the downstream side than on the upstream side, and at least one of the plurality of locations where the reinforcing fibers are supplied into the cylinder is the cylinder. It is configured to supply from the downstream side of the position. Further, in the section from a predetermined one place to the other one place among the plurality of places where the reinforcing fibers are supplied to the cylinder, the shearing force is made larger than the other sections depending on the shape of the screw, and the kneading is performed.

That is, according to the first aspect of the present invention, the thermoplastic resin and the reinforcing fiber are supplied to the cylinder by a plasticizer including the cylinder and the screw inserted in the cylinder, and the screw is rotated to rotate the fiber. It is a kneading method for obtaining a reinforced thermoplastic resin, in which the plasticizing device makes the clearance between the bore of the cylinder and the screw larger on the downstream side than the upstream side from a predetermined cylinder position, and the reinforcing fibers are used as described above. When supplying into the cylinder, the fiber-reinforced thermoplastic resin is characterized in that it is supplied from a plurality of different locations in the cylinder and at least one of the plurality of locations is on the downstream side of the predetermined cylinder position. It is configured as a kneading method.
The invention according to claim 2 is the kneading method according to claim 1, wherein in the section from a predetermined one place to the other one place among the plurality of places where the reinforcing fiber is supplied to the cylinder, the screw is used. It is configured as a method of kneading a fiber-reinforced thermoplastic resin, which is characterized in that the shearing force is made larger than that of other sections depending on the shape and kneaded.

The invention according to claim 3 comprises a cylinder and a screw rotating in the cylinder, and the thermoplastic resin is supplied to the cylinder and melted, and the reinforcing fibers are supplied and kneaded to form a fiber-reinforced thermoplastic resin. a plasticizing device obtained is, the cylinder is provided a plurality of locations reinforcing fiber inlet of reinforcing fibers is introduced is provided so as reinforcing fibers from a plurality of locations is turned in parallel, the A fiber-reinforced thermoplastic resin characterized in that the clearance between the bore of the cylinder and the screw is larger than that on the upstream side in the downstream from a predetermined one of the plurality of reinforcing fiber inlets. It is configured as a plasticizer.
The invention according to claim 4 is the plasticizing device according to claim 3 , wherein the plasticizing device is composed of a twin-screw extruder having two screws, and the bore of the cylinder is two circles of the same size. Has a cross-sectional shape in which only a part of the resin is overlapped with each other, thereby forming barrel tips inward from the upper and lower two positions. The bore is configured as a fiber-reinforced thermoplastic resin plasticizing device, characterized in that at least one of the upper and lower barrel tips has a cut shape.
The invention according to claim 5 is the above-mentioned in the section between the predetermined one reinforcing fiber inlet and the other one reinforcing fiber inlet in the plasticizing apparatus according to claim 3 or 4. The screw is configured as a fiber-reinforced thermoplastic resin plasticizing device characterized in that a flight having a large shearing force during kneading is formed as compared with other sections.

As described above, according to the present invention, the plasticizer provided with the cylinder and the screw inserted in the cylinder supplies the thermoplastic resin and the reinforcing fiber to the cylinder and rotates the screw to perform fiber reinforced plasticity. The target is a kneading method for obtaining a resin. The plasticizing device as bores and screw clearance of the cylinder is increased downstream from the predetermined cylinder position is compared with the upstream side, when supplying reinforcing fibers into the cylinder, is supplied from a plurality of places different in the cylinder At least one of the plurality of locations is configured to be on the downstream side of the predetermined cylinder position. Then, the reinforcing fibers supplied on the upstream side are kneaded over a long distance and are subjected to the action of shearing force. Therefore, although some fibers are cut by kneading, the reinforcing fibers can be uniformly dispersed in the resin. can. On the other hand, since the reinforcing fibers supplied on the downstream side can be kneaded only for a short distance, the dispersion in the resin may be insufficient, but the cutting due to kneading can be reduced. That is, a large proportion of reinforcing fibers having an appropriate fiber length can be left. As a result, relatively short reinforcing fibers are uniformly dispersed in the resin, and relatively long fibers are contained in a predetermined ratio. In other words, there are two requirements that were considered to be antinomy: that the reinforcing fibers are uniformly dispersed in the fiber-reinforced thermoplastic resin, and that many reinforcing fibers of an appropriate fiber length remain. Can also be met. Reinforcing fibers develop some strength even if they are relatively short, and if there is an appropriate fiber length, they develop sufficiently high strength. Therefore, when a molded product is molded from such a fiber-reinforced thermoplastic resin, it is possible to obtain a molded product having high strength as a whole while suppressing uneven distribution of strength depending on the location. Then, the reinforcing fibers supplied from one place at a predetermined cylinder position can sufficiently suppress cutting. Therefore, a sufficient proportion of reinforcing fibers having an appropriate fiber length can be left in the resin. According to still another invention, in the section from a predetermined one place to the other one place among the plurality of places where the reinforcing fibers are supplied to the cylinder, the shearing force is made larger than the other sections by the shape of the screw to knead. ing. Then, the reinforcing fibers can be forcibly dispersed in the resin in this section.

It is a figure which shows the molding apparatus which concerns on embodiment of this invention, (a) is the front view which shows the molding apparatus in a partial cross section, (b) and (c) are the embodiment of this invention which constitute molding apparatus. It is sectional drawing which cut in XX and YY respectively about the twin-screw extruder which concerns on the form. It is a figure which shows the state of kneading a reinforcing fiber and a thermoplastic resin in a twin-screw extruder. It is a cross-sectional view of. It is a front view which shows the molding apparatus which concerns on other Embodiment of this invention in a partial cross section. It is sectional drawing of the extruder of the single shaft screw which concerns on other embodiment of this invention, (a) is the sectional view of the upstream side of the extruder, and (b) is the sectional view of the downstream side from a reinforcing fiber inlet. It is a figure.

Embodiments of the present invention will be described. As shown in FIG. 1A, the molding apparatus 1 according to the present embodiment is a plasticizing apparatus for kneading a thermoplastic resin and reinforcing fibers to obtain a fiber-reinforced thermoplastic resin, that is, the present embodiment. The twin-screw extruder 2 according to the above embodiment, the molding die 4 for obtaining a molded product by compression molding the massive intermediate molded product extruded from the twin-screw extruder 2, and the molding die 4 are molded. It is composed of a mold clamping device 5 and a robot arm 7 that conveys a massive intermediate molded product extruded from the twin-screw extruder 2 to a molding mold 4.

The twin-screw extruder 2 according to the present embodiment also has a cylinder 9 in which a plurality of cylinder blocks 9a, 9b, ... It is composed of book screws 11 and 11. A hopper 12 is provided upstream of, that is, at the rear end of the cylinder 9, to supply thermoplastic resin pellets. As will be described next, reinforcing fibers are also supplied to the cylinder 9, and the thermoplastic resin and the reinforcing fibers are kneaded by the screws 11 and 11 to obtain a fiber-reinforced thermoplastic resin. A predetermined die 15 on which the fiber-reinforced thermoplastic resin is extruded is provided at the tip of the cylinder 9, and although not shown in the figure, a cutter that cuts the extruded reinforced fiber thermoplastic resin to a predetermined size is a die. It is provided in connection with 15. As a result, a bulk intermediate molded product can be obtained. A plurality of heaters are provided on the outer peripheral surface of the cylinder 9 to heat the cylinder 9, but this is not shown in FIG.

The twin-screw extruder 2 according to the present embodiment is characterized in that two reinforcing fiber supply ports are provided at predetermined intervals in the axial direction. That is, the first and second reinforcing fiber inlets 13 and 14 are provided. In the present embodiment, the first reinforcing fiber input port 13 is provided in the cylinder block 9j near the center of the cylinder 9, and the second reinforcing fiber input port 14 is provided in the cylinder block 9 m near the tip of the cylinder 9. ing. Reinforcing fiber rolls 18 and 19 are provided in connection with these first and second reinforcing fiber inlets 13 and 14, and rope-shaped reinforcing fiber bundles, that is, rovings are pulled out and the first and second reinforcing fiber inlets are drawn out. It is designed to be supplied to 13 and 14.

The twin-screw extruder 2 according to the present embodiment is also characterized by the bores 17a and 17b of the cylinder 9 in which the screws 11 and 11 are inserted. On the upstream side of the second reinforcing fiber inlet 14, that is, in the section indicated by reference numeral 20 in (a) of FIG. 1, the bore 17a is formed in the same shape as the bore of a conventional twin-screw extruder. There is. However, in the section from the vicinity of the second reinforcing fiber inlet 14 to the downstream side, that is, the section indicated by reference numeral 21, the bore 17b is formed in a shape different from that of the conventional twin-screw extruder. This will be explained. First, in the section of reference numeral 20, the bore 17a has a shape in which two horizontally arranged circles of the same size partially overlap each other, as shown in FIG. 1 (a). .. As a result, the bore 17a is formed with protrusions, that is, barrel tips 23, 23, which are directed inward on the upper side and the lower side, respectively. Two screws 11 and 11 are inserted in the bore 17a having such a shape. On the other hand, in the section of reference numeral 21, the upper barrel tip 23 of the bore 17b is cut off as shown in FIG. 1 (c), and the upper portion thereof is flat. .. Further, the diameter of the two circles whose parts overlap each other is slightly larger than the two circles of the bore 17a shown in FIG. 1 (a). Therefore, the clearance between the bore 17b and the screws 11 and 11 is larger than that on the upstream side, as indicated by reference numeral 24.

The twin-screw extruder 2 according to the embodiment of the present invention is also characterized in the flight shape of the screws 11 and 11. First, the screws 11 and 11 are formed with flights in the vicinity of the first and second reinforcing fiber inlets 13 and 14 so that the transport capacity is larger than that of the other sections. Since the transport capacity is large, starvation sections 25 and 26 in which the resin pressure drops are formed in the vicinity of the first and second reinforcing fiber inlets 13 and 14. As the shape of the flight in the starvation sections 25 and 26, for example, the depth of the groove between the flights may be deepened, or the flight width may be narrowed. In the present embodiment, the flight pitch is made larger than that of other parts so that the transport capacity is increased. In the present embodiment, the screws 11 and 11 have double flights in the starvation sections 25 and 26.

In the present embodiment, the screws 11 and 11 are provided with a kneading section 27 for strengthening the kneading action in the section sandwiched between the first reinforcing fiber input port 13 and the second reinforcing fiber input port 14. Is also characteristic. For example, a kneading flight may be provided in the kneading section 27, but in the present embodiment, a mixing flight is provided.

In the present embodiment, the molding die 4 is composed of a die for molding a molded product by compression molding. The mold clamping device 5 for mold-clamping the molding die 4 is adapted to mold-clamp by a toggle mechanism or a mold-clamping cylinder.

A molding method for obtaining a fiber-reinforced thermoplastic resin and molding a molded product by the molding apparatus 1 according to the present embodiment will be described. In the twin-screw extruder 2 according to the embodiment of the present invention, the screws 11 and 11 are rotated to supply the pellets of the thermoplastic resin from the hopper 12. The pellet melts in the cylinder 9 and is fed forward. The pressure of the molten resin drops in the starvation section 25. The roving drawn from the reinforcing fiber roll 18, that is, the reinforcing fiber 28 is supplied into the cylinder 9 from the first reinforcing fiber input port 13. Since the resin pressure is reduced by the starvation section 25, the supply of the reinforcing fibers can be easily carried out. When the reinforcing fibers 28 are supplied into the cylinder 9 and kneaded by the rotation of the screws 11 and 11, a part thereof is around the two screws 11 and 11 as shown in FIG. 2 (a). It will be in a rolled state. The reinforcing fibers 28 are pressed by the barrel tips 23, 23 and exert a strong tension, and friction acts between the bore 17a of the cylinder 9 and the screws 11, 11 as indicated by reference numerals 31 and 32. .. Therefore, it is cleaved by these actions. It is also cut by the shearing force of kneading with the resin, and the relatively short reinforcing fibers are uniformly dispersed in the resin. Such a resin, that is, a fiber-reinforced thermoplastic resin is kneaded more strongly by the kneading section 27, and the dispersibility of the reinforcing fibers is further increased. When the fiber-reinforced thermoplastic resin is sent to the starvation section 26, the resin pressure drops again. The roving drawn from the reinforcing fiber roll 19, that is, the reinforcing fiber 29 is supplied into the cylinder 9 from the second reinforcing fiber input port 14. In the section indicated by reference numeral 21, the clearance between the bore 17b of the cylinder 9 and the screws 11 and 11 is large, and the barrel tip 21 is provided only on the lower side. A part of the reinforcing fiber 29 supplied from the second reinforcing fiber input port 14 is wound around the screws 11 and 11, as shown in FIG. 2 (a), and the reinforcing fiber 29 is wound around the screws 11 and 11. Since the tension acting on the fiber is small and the clearance between the bore 17b and the screw 11 is large, friction is unlikely to act. That is, the reinforcing fiber 29 is difficult to cut. The reinforcing fibers 29 are cut by the shearing force of kneading, but they are not cut too much and become finer. Then, in the fiber-reinforced thermoplastic resin, sufficient reinforcing fibers having an appropriate fiber length remain. That is, the fiber-reinforced thermoplastic resin obtained by the twin-screw extruder 2 according to the present embodiment has relatively short reinforcing fibers uniformly dispersed and sufficiently contains reinforcing fibers having an appropriate fiber length. Become. As shown in FIG. 1A, a predetermined amount of fiber-reinforced thermoplastic resin is extruded from the die 15 and cut with a predetermined cutter. Then, a massive intermediate molded product is obtained. The massive intermediate molded product is grasped by the robot arm 7 and carried into the cavity of the mold 4 for molding which has been opened. The mold clamping device 5 is driven to perform compression molding. When the mold is opened after waiting for cooling and solidification, a molded product is obtained. Hereinafter, molding is performed in the same manner.

The method for kneading the fiber-reinforced thermoplastic resin according to the present embodiment is characterized in that when the reinforcing fibers are supplied to the plasticizing device, they are supplied from two or more different locations, but as a plasticizing device. The kneading method according to the present invention can also be carried out by using the injection device of the injection molding machine. FIG. 3 shows a molding apparatus 35 according to the second embodiment, that is, an injection molding machine 35. The injection device 36, that is, the plasticization device of the injection molding machine 35 is composed of a cylinder 37 and a screw 38 driven in the cylinder 37 in the axial direction and the rotational direction. A hopper 40 is provided at the rear end of the cylinder 37, and a reinforcing fiber input port 41 is provided near the tip. The screw 38 has a deep flight groove in the vicinity of the reinforcing fiber input port 41, and is a starvation section in which the resin pressure drops. An injection nozzle 43 is provided at the tip of the cylinder 37, and is in contact with the sprue of the molding die 45 to be molded by the mold clamping device 44. In the molding apparatus 35 according to the second embodiment, the hopper 40 not only supplies pellets of thermoplastic resin but also supplies reinforcing fibers. A reinforcing fiber supply device 46 is provided corresponding to the hopper 40, and the reinforcing fiber supply device 46 includes a reinforcing fiber roll 47 and a cutting device 48. The roving reinforcing fibers drawn from the reinforcing fiber roll 47 are cut by the cutting device 48 and supplied from the hopper 40 into the cylinder 37. Although not shown in the drawing, the hopper 40 is provided with a predetermined feeder so that the pellets of the thermoplastic resin and the reinforcing fibers are supplied into the cylinder 9 at a constant ratio. When the screw 38 is rotated, the pellets supplied from the hopper 40 and the reinforcing fibers are sent forward, the pellets are melted, kneaded together with the reinforcing fibers, and the reinforcing fibers are cut by a shearing force. That is, a fiber-reinforced thermoplastic resin in which relatively short reinforcing fibers are uniformly dispersed can be obtained. Such a fiber-reinforced thermoplastic resin is sent by the screw 38 to reduce the resin pressure in the starvation section. The roving reinforcing fibers drawn from the reinforcing fiber roll 49 are supplied into the cylinder 37 from the reinforcing fiber input port 41. The reinforcing fibers supplied here are also cut to some extent by the shearing force of kneading, but sufficient reinforcing fibers having an appropriate fiber length remain. That is, the fiber-reinforced thermoplastic resin in which the relatively short reinforcing fibers are uniformly dispersed and sufficiently contains the reinforcing fibers having an appropriate fiber length is weighed. The molding die 45 is molded by the mold clamping device 44, and the screw 38 is driven to inject the fiber-reinforced thermoplastic resin. A molded product can be obtained by opening the mold after waiting for cooling and solidification.

The molding apparatus 1 or the molding apparatus 35 according to the present embodiment can be variously deformed. For example, although the number of inlets for the reinforcing fibers has been described as two, there may be three or more. Further, the reinforcing fiber may be supplied as it is as roving, or may be cut and supplied. Further, it is also conceivable to use pellets containing reinforcing fibers as pellets supplied from the hoppers 12 and 40. In this case, if the reinforcing fibers are further supplied from the other one location in the cylinders 9 and 37, the reinforcing fibers are substantially supplied from the two locations. That is, the reinforcing fibers are supplied from two different locations in the cylinders 9 and 37. Then, a fiber-reinforced thermoplastic resin in which relatively short reinforcing fibers are uniformly dispersed and sufficiently containing reinforcing fibers having an appropriate fiber length can be obtained. That is, the method for kneading the fiber-reinforced thermoplastic resin according to the present invention can be carried out.

It is also possible to deform the bore 17b of the twin-screw extruder 2 in the molding apparatus 1 according to the present embodiment. In the twin-screw extruder 2, the clearance between the bore 17b and the screws 11 and 11 is larger from the vicinity of the second reinforcing fiber input port 14 to the downstream side as compared with the upstream side, and the second reinforcing fiber input port 14 is provided. It was explained that at least one of the upper and lower barrel tips 23, 23 was removed from the vicinity to the downstream of the above. However, the clearance between the bores 17a and 17b and the screws 11 and 11 may be constant, and the barrel tips 23 and 23 may not be removed. In this way, the reinforcing fibers input from the second reinforcing fiber input port 14 are easily cut, but the kneading time is shorter than that of the reinforcing fibers supplied from the first reinforcing fiber input port 13. , Reinforcing fibers of appropriate fiber length will remain sufficient. Alternatively, deformation in the opposite direction to such deformation is also possible. That is, the clearance between the bore 17b and the screws 11 and 11 may be increased from the vicinity of the second reinforcing fiber inlet 14 to the downstream, and both the upper and lower barrel tips 23 and 23 may be removed. In this way, the cutting of the reinforcing fibers supplied from the second reinforcing fiber input port 14 is further suppressed.

As the method for kneading the fiber-reinforced thermoplastic resin according to the embodiment of the present invention, an extruder having a single shaft can also be used as a plasticizing device. Even when the extrusion is carried out by a single-screw extruder, the reinforcing fibers may be supplied from two or more different locations in the cylinder. When the reinforcing fibers are supplied from two locations in the cylinder, the upstream side thereof is the bore 51 of the cylinder 50 as shown in FIG. 4 (a) with respect to the most downstream supply location. It is preferable to reduce the clearance with the screw 52 and increase the clearance between the bore 51 of the cylinder 50 and the screw 52 on the downstream side as shown in (a) of FIG. Then, the reinforcing fibers supplied on the upstream side in the extruder are cut by kneading with the resin and become slightly shorter, but are uniformly dispersed in the fiber-reinforced thermoplastic resin, and the reinforcing fibers supplied on the downstream side. Is difficult to cut, and a sufficient amount of reinforcing fiber having an appropriate fiber length remains.

1 Molding equipment 2 Biaxial extruder 4 Molding mold 5 Mold clamping device 7 Robot arm 9 Cylinder 11 Screw 12 Hopper 13 First reinforcing fiber input port 14 Second reinforcing fiber input port 15 Die
17a, 17b Bore 18 Reinforced fiber roll 19 Reinforced fiber roll 23 Barrel tip 25 Hunger section 26 Hunger section 27 Kneading section 28 Reinforced fiber 29 Reinforced fiber 35 Injection molding machine 36 Injection device 37 Cylinder 38 Screw 40 Hopper 41 Reinforced fiber inlet 43 Injection Nozzle 44 Mold clamping device 45 Molding mold 46 Reinforcing fiber supply device 47 Reinforcing fiber roll 48 Cutting device 49 Reinforcing fiber roll

Claims (5)

A kneading method in which a thermoplastic resin and reinforcing fibers are supplied to the cylinder by a plasticizer equipped with a cylinder and a screw placed in the cylinder, and the screw is rotated to obtain a fiber-reinforced thermoplastic resin. ,
The plasticizer makes the clearance between the bore of the cylinder and the flight of the screw larger from the predetermined cylinder position on the downstream side than on the upstream side.
When the reinforcing fiber is supplied into the cylinder, the fiber is supplied from a plurality of different locations in the cylinder, and at least one of the plurality of locations is on the downstream side of the predetermined cylinder position. Kneading method of reinforced thermoplastic resin. In the kneading method according to claim 1, in the section from a predetermined one place to the other one place among the plurality of places where the reinforcing fiber is supplied to the cylinder, the shearing force is increased from the other section by the shape of the screw. A method for kneading a fiber-reinforced thermoplastic resin, which is characterized in that it is enlarged and kneaded. A plasticizing device consisting of a cylinder and a screw rotating in the cylinder, in which a thermoplastic resin is supplied to the cylinder and melted, and at the same time, reinforcing fibers are supplied and kneaded to obtain a fiber-reinforced thermoplastic resin. ,
The cylinder, the reinforcing fibers inlet of reinforcing fibers is introduced is provided a plurality of locations are adapted to the reinforcing fibers from a plurality of locations is turned in parallel, a predetermined one of the reinforcing fiber inlet of the plurality of locations A fiber-reinforced thermoplastic resin plasticizing device, characterized in that the clearance between the bore of the cylinder and the flight of the screw is larger than that on the upstream side from one location to the downstream. In the plasticizing device according to claim 3 , the plasticizing device is composed of a twin-screw extruder having two screws, and the bore of the cylinder has a cross-sectional shape in which two circles of the same size partially overlap each other. As a result, barrel tips are formed inward from the upper and lower two locations, respectively, and the bore is at least one of the upper and lower barrels downstream from a predetermined one of the plurality of reinforcing fiber inlets. A fiber-reinforced thermoplastic resin plasticizing device characterized in that the chip has a cut shape. In the plasticizing apparatus according to claim 3 or 4, in the section between the predetermined reinforcing fiber inlet and the other reinforcing fiber inlet, the screw is compared with the other section. A fiber-reinforced thermoplastic resin plasticizing device characterized in that a flight having a large shearing force during kneading is formed.

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