JPH0880576A - Method and apparatus for producing resin molding material - Google Patents

Abstract

PURPOSE: To stably produce a fiber reinforced thermoplastic resin material containing an inorg. long fiber as a reinforcing material and high in mechanical strength at high speed. CONSTITUTION: A continuous inorg. fiber bundle 12 is impregnated with a molten thermoplastic resin 14 and the excessive resin is pressed from the impregnated fiber bundle 12 by the squeezing bar 18 composed of at least one rod 28 arranged so as to cross the running direction of the fiber bundle 12, pref. at a right angle thereto and, thereafter, the impregnated fiber bundle 12 is shaped by a shaping device consisting of at least a pair of rollers 25 arranged so as to come into contact with the fiber bundle 12 on the opposite sides thereof to prepare a long fiber reinforced thermoplastic resin material. The process impregnating the fiber bundle 12 with the molten thermoplastic resin 14 and the process pressing the excessive resin from the fiber bundle by the squeezing bar 18 are pref. performed in an inert gas atmosphere. As the inorg. fiber, a glass fiber is pref. used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long fiber reinforced thermoplastic resin molding material (LF) using a continuous inorganic fiber bundle as a reinforcing material.
RTP) manufacturing method and manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, as a means for improving the rigidity, heat resistance and the like of a thermoplastic resin, blending of an inorganic fiber such as a glass fiber as a reinforcing material has been performed.

Usually, chopped strands are often used as such reinforcing materials from the viewpoint of resin impregnation. Such a fiber-reinforced thermoplastic resin molding material using a chopped strand as a reinforcing material is pelletized by extruding a chopped strand having a length of about 3 to 6 mm and a thermoplastic resin by heating and kneading with an extrusion screw,
It is manufactured by a method of blending these pellets and molding a resin.

However, when chopped strands are used as a reinforcing material, there are the following problems. That is, when the chopped strands and the thermoplastic resin are heated and kneaded by the extruder, the chopped strands are cut due to friction between the extrusion screw and the chopped strands. Also, when molding the fiber-reinforced thermoplastic resin molding material, because the cutting occurs by friction with the screw of the injection molding machine, the glass fiber is cut further shorter,
Initially, the fiber length was 3-6 mm, but finally 0.05-0.8
mm. For this reason, the mechanical properties, especially the impact resistance, of the molded product could not be sufficiently improved.

In order to solve the above problems, recently, for example, Japanese Patent Publication No. 52-10140, Japanese Patent Application Laid-Open No. 63-264326, US Pat.
As disclosed in Japanese Patent No. 439,387, etc., a method has been employed in which continuous inorganic fibers are impregnated with a molten thermoplastic resin by an electric wire coating method. In the case of this method, there is a problem that the molten resin is difficult to impregnate even into the inside of the fiber bundle, so in the above publication, various methods of impregnation have been studied, but the manufacturing process is generally
In the impregnation die, after impregnating the continuous fiber bundle with the molten resin, pass through a nozzle having a predetermined hole diameter provided at the tip of the impregnation die, a slit or a die, or pass an excess resin through a shaping die. It is removed to obtain a predetermined fiber content and a predetermined shape to obtain a long fiber reinforced thermoplastic resin molding material.

FIG. 5 shows an example of a manufacturing process of a conventional long fiber reinforced thermoplastic resin molding material, and FIG. 6 shows an example of a drawing die using a choke bar used in the conventional manufacturing process. It is shown. 5 and 6 together, a fiber bundle 12 of glass long fibers drawn out from a wound body such as a roving or cake (not shown) is continuously supplied to a drawing die 61 and an extruder. From 63, the molten thermoplastic resin 14 is supplied to the die 61, the tension is applied to the fiber bundle 12 by the choke bar 65 inside the die 61, and the thermoplastic resin 14 is impregnated with the fiber bundle 12 being opened. Then, after being pulled out from the nozzle 66 to obtain the long fiber reinforced thermoplastic resin 15, the cooling bath 16
Then, the thermoplastic resin 14 is hardened by cooling, and is then taken off by a take-off machine 17.

[0007]

However, in any of the above methods, when the drawing is performed at a high speed, a considerably large stress is applied to the fiber bundle, so that the monofilament in the fiber bundle is cut in the die, and the so-called monofilament is cut. Easy to break thread. Therefore, the broken filaments are accumulated in the die and become fluff, and the fluff moves to the discharge port of the die to close the nozzle, the slit, or the die, and the tensile resistance of the fiber bundle increases to easily induce the breakage. There was a problem. Therefore, at the time of high-speed molding, it is necessary to disassemble the die from time to time to remove fluff accumulated in the die, and it has been practically difficult to perform high-speed and smooth continuous production.

The present invention has been made in view of the above problems, and an object thereof is to stably produce a fiber-reinforced thermoplastic resin material having high mechanical strength using inorganic long fibers as a reinforcing material at a high speed. To provide a manufacturing method and a manufacturing apparatus.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, after impregnating a continuous inorganic fiber bundle with a molten resin, excess resin was squeezed with a squeeze bar. For the squeezing and the running direction of the fiber bundle,
The present invention was found to be one in which single yarn breakage is less likely to occur and stable production can be performed at high speed by performing shaping by a shaping device including at least a pair of rollers arranged so as to contact each other from opposite sides. It came to completion.

In order to achieve the above-mentioned object, the method for producing a long fiber reinforced thermoplastic resin molding material according to the present invention is such that a continuous fiber bundle of inorganic fibers is impregnated with a molten thermoplastic resin and then shaped. In the method for producing a fiber-reinforced thermoplastic resin molding material, a step of impregnating the fiber bundle with the thermoplastic resin, and above the resin surface of the molten thermoplastic resin, with respect to the running direction of the fiber bundle A step of squeezing out excess resin by a squeeze bar composed of at least one rod arranged so as to intersect, and at least a pair of at least one pair arranged so as to come into contact with each other from the opposite side with respect to the running direction of the fiber bundle. And a step of performing shaping by a shaping device including a roller.

In addition, the apparatus for producing a long-fiber-reinforced thermoplastic resin molding material of the present invention impregnates a continuous fiber bundle of inorganic fibers with a molten thermoplastic resin and then shapes the fiber bundle to form a long-fiber-reinforced thermoplastic resin. In an apparatus for producing a resin molding material, a resin inflow port into which the thermoplastic resin flows, an impregnation tank in which the thermoplastic resin is stored, and an introduction port for introducing the fiber bundle and leading to the impregnation tank, An outlet for taking out the fiber bundle from the impregnation tank, and a coating device having a squeeze bar including at least one rod disposed so as to intersect the running direction of the fiber bundle at the outlet. A shaping device including at least a pair of rollers disposed so as to be in contact with each other from the opposite side with respect to the traveling direction of the fiber bundle taken out of the coating device through a squeeze bar. And wherein the door.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments.

[0013] The thermoplastic resin used in the present invention includes:
Although not particularly limited, for example, polyethylene, polypropylene, nylon, PET (polyethylene terephthalate), PBT (polybutylene terephthalate), polystyrene, AS (acrylonitrile styrene resin), AB
S (acrylonitrile butadiene styrene resin), PE
I (polyether imide), PEEK (polyether ether ketone) and the like are preferably used. In the present invention,
The above resins may be used alone or in combination of two or more. Further, the thermoplastic resin may appropriately contain known additives such as a colorant, an improving agent, and a filler other than the inorganic fiber depending on the use and molding conditions, and these are kneaded and used according to a conventional method. It

In the present invention, as the continuous fiber bundle of inorganic fibers, glass fibers, carbon fibers and the like drawn from a wound body such as cake and roving are preferably used. Among these, the use of commercially available glass fibers such as E glass and S glass is more advantageous in terms of cost and is more preferable. The number of bundles of the fiber bundles is preferably about 100 to 4,000 in consideration of handleability, spreadability when the molten resin is impregnated, and the like. In general, glass fibers are subjected to various surface treatments for improving handling, improving adhesiveness with a matrix during compounding, etc., but these types are used. It may be selected according to the thermoplastic resin.

An apparatus for producing a long-fiber-reinforced thermoplastic resin molding material of the present invention is basically constituted by an apparatus shown in FIGS. 1 and 2, for example. FIG. 1 is a partial cross-sectional side view,
FIG. 2 is a plan view.

In FIGS. 1 and 2, a continuous fiber bundle 12 of inorganic fibers drawn from a winding body or the like (not shown) is introduced into a coating device 11 to be impregnated with a molten thermoplastic resin 14, and a squeeze bar. After the excess resin 14 is squeezed out by 18, the shaping is performed by the shaping device 19. The long fiber reinforced thermoplastic resin 15 thus obtained is subjected to a usual process,
It is cooled in a cooling tank 16 and taken off by a take-off machine 17 to obtain a long fiber reinforced thermoplastic resin molding material.

The coating device 11 includes a resin inlet 21 into which the thermoplastic resin 14 flows, an impregnation tank 22 in which the thermoplastic resin 14 is stored, and an inlet 23 that introduces the fiber bundle 12 and guides it to the impregnation tank 22. The outlet 24 for taking out the fiber bundle 12 impregnated with the thermoplastic resin 14 from the impregnation tank 22 and the outlet 24 are arranged at right angles so as to intersect the traveling direction of the fiber bundle 12. And a squeeze bar 18 including at least one rod 28. In addition, as the inlet 23, a slit-like hole of, for example, about 3 mm × 12 mm is preferably adopted. In addition, the outlet 24 only needs to take out the fiber bundle 12 impregnated with the thermoplastic resin 14 and does not need to have a function of squeezing out the excess resin 14 or shaping it. Not slit or die-shaped.

Then, the impregnation tank 14 and the squeeze bar 18
Is covered with the inert gas atmosphere tank 20, and the gas inlet 26
, An inert gas 27 is introduced. Therefore, the step of impregnating the fiber bundle 12 with the thermoplastic resin 14 and the step of squeezing out the excess resin 14 with the squeeze bar 18 are performed in an atmosphere of the inert gas 27. The inert gas atmosphere tank 20 is not always necessary, but is preferably provided because the molten thermoplastic resin 14 can be prevented from being oxidized and degraded. Inert gas 27
As such, nitrogen, argon, helium and the like are preferably used.

In the coating apparatus 11 shown in FIGS. 1 and 2, the fiber bundle 12 is immersed in an impregnation tank 22 in which the thermoplastic resin 14 is stored, so that the thermoplastic resin 14 is impregnated. Although adopted, it is not limited to this method, and it may be impregnated using a hot melt roll coater or the like. The molten thermoplastic resin 1
When the viscosity of No. 4 is high, it is more preferable to provide a choke bar in the impregnation tank 22.

The squeeze bar 18 is composed of at least one rod 28 arranged at right angles to the traveling direction of the fiber bundle 12, and is arranged above the outlet 24. The shape of the rod 28 is preferably such that the contact surface with the fiber bundle 12 has a smooth curved surface, and for example, the cross section thereof is preferably a circle, an ellipse, a semicircle, or the like. Also, its material,
The diameter, the number, etc. are not particularly limited, and the thermoplastic resin 14 to be used
Is selected according to the type of the fiber, the fiber content to be obtained, and the like. When using a plurality of rods 28, the fiber bundle 1
By alternately passing the two so as to sew between them, the excess thermoplastic resin 14 can be efficiently squeezed out.

The shaping device 19 used in the present invention is a fiber bundle 1 taken out from the coating device 11 via the squeeze bar 18.
2, that is, at least one pair of rollers 25, 25 arranged to be in contact with the running direction of the uncured long fiber reinforced thermoplastic resin 15 from opposite sides. By passing between the rollers 25, 25, a desired shape such as a circular rod shape or a tape shape can be formed. In this embodiment, the rollers 25, 2
5 has an arcuate recess at the center, and is configured to shape the long fiber reinforced thermoplastic resin 15 from the horizontal direction into a circular rod shape. However, the shape and arrangement position of the roller 25 are not limited to this, and for example, as shown in the side view of FIG. 3 and the plan view of FIG.
Accordingly, the long-fiber-reinforced thermoplastic resin 15 may be shaped in a vertical direction. In this case, the long fiber reinforced thermoplastic resin 15 is shaped like a tape.

A feature of the present invention is that the squeeze bar 1 described above is used.
8 are provided in the coating device 11 and the shaping device 19, and other cooling tanks 16, take-up devices 17, etc. can be used as they are.

[0023]

According to the present invention, a continuous inorganic fiber bundle is impregnated with a molten thermoplastic resin, and then excess resin is squeezed out with a squeeze bar. Since shaping is performed by a shaping device consisting of at least a pair of rollers arranged so as to be in contact from the side, single yarn breakage is unlikely to occur even when pulled at high speed, and therefore, the long fiber reinforced thermoplastic resin molding material can be stabilized at high speed. Can be manufactured.

Further, in a preferred embodiment, when the impregnation tank and the squeeze bar are arranged in an inert gas atmosphere, a step of impregnating the fiber bundle with the thermoplastic resin and a squeeze bar to squeeze out excess resin Since the step and the step are performed in an inert gas atmosphere, it is possible to prevent oxidative deterioration of the molten thermoplastic resin, and it is possible to produce a high-quality long fiber reinforced thermoplastic resin molding material.

[0025]

【Example】

Example 1 A long fiber reinforced thermoplastic resin molding material was produced using the apparatus shown in FIGS. 1 and 2 described above.

As a continuous fiber bundle 12 of inorganic fibers, a fiber bundle 13 in which 800 E glass fibers having a fiber diameter of 13 μm are bundled
A book obtained by arranging books was used, and a polypropylene resin was used as the thermoplastic resin 14.

As the squeeze bar 18, 8 mmφ
The five glass rods were arranged at a pitch of 15 mm at right angles to the running direction of the fiber bundle 12.

The inert gas atmosphere tank 20 was an acrylic box, and nitrogen gas was introduced from the gas inlet 26 at 1 m ³ / min.

As the shaping device 19, the fiber bundles 12 taken out from the coating device 11, that is, the left and right sides are arranged so as to come in contact with the running direction of the uncured long fiber reinforced thermoplastic resin 15 from opposite sides. A pair of rollers 25 having a circular arc-shaped concave portion was used.

The cooling tank 16 and the take-up machine 17 used were conventional ones, and the take-up speed was 60 m / min.

Under the above conditions, the fiber bundle 12 is introduced into the impregnation tank 22, the resin 14 is impregnated, and the squeeze bar 18 is added.
After squeezing out the excess resin with, it is shaped with the shaping device 19,
The glass content was reduced to 72 through the cooling tank 16 and the take-off machine 17.
A long rod reinforced thermoplastic resin molding material in the form of a circular rod was obtained in wt%.

Then, the obtained long fiber reinforced thermoplastic resin molding material was cut into a length of 6 mm. A predetermined amount of polypropylene was added to the cut product as pellets for a masterbatch, and a test piece having a glass content of 20 wt% was obtained by an injection molding machine.

Embodiment 2 In Embodiment 1, the shaping apparatus 19 is brought into contact with the running direction of the uncured long fiber reinforced thermoplastic resin 15 shown in FIGS. In place of a pair of cylindrical rollers 29, 29 arranged vertically, a long fiber reinforced thermoplastic resin 15 is shaped into a tape having a width of about 6 mm and a thickness of about 0.3 mm. With the same materials, equipment and conditions as in Example 1, the glass content was 73
A tape-shaped long-fiber-reinforced thermoplastic resin molding material was obtained with a wt%.

The obtained long-fiber-reinforced thermoplastic resin molding material was treated in the same manner as in Example 1 to obtain a test piece.

Comparative Example 1 A long fiber reinforced thermoplastic resin molding material was produced by using the apparatus shown in FIGS. 5 and 6 and using the same fiber bundle 12 and thermoplastic resin 14 as in Example 1.

The diameter of the nozzle 66 provided on the die 61 is 2.
0 mmφ.

Under the above conditions, the fiber bundle 12 is introduced into the impregnation tank 22, impregnated with the resin 14, and the excess resin 14 is squeezed through the nozzle 66 and shaped, and the cooling tank 16 and the take-up machine 17 are provided. Through, glass content rate 72 wt%,
A circular rod shaped long fiber reinforced thermoplastic resin molding material was obtained. The take-up speed was 20 m / min.

The obtained long-fiber-reinforced thermoplastic resin molding material was treated in the same manner as in Example 1 to obtain a test piece.

Comparative Example 2 In Comparative Example 1, the take-up speed was changed to 40 m / min, and the long fiber-reinforced thermoplastic resin molding material was obtained in the same manner as in Comparative Example 1 and treated in the same manner as in Comparative Example. A test piece was obtained.

Test Examples The test pieces obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were observed for fiber dispersion. The results are shown in Table 1.

[0041]

[Table 1] In the table, PP represents polypropylene.

From the results of Table 1, the test pieces of Examples 1 and 2 produced by the production method of the present invention using the apparatus of the present invention,
In the state where the fiber dispersibility is good, there is no breakage of the fiber at the time of drawing at a drawing speed of 60 m / min. However, in Comparative Examples 1 and 2 using the conventional apparatus, all of the fibers were broken. The dispersibility is good, but as in Comparative Example 2, the take-off speed is 40 m / mi.
It can be seen that when the fiber is taken at n, the fiber breaks at the time of taking.

[0043]

As described above, according to the present invention,
A fiber bundle of continuous inorganic fibers is impregnated with a molten thermoplastic resin, and after squeezing excess resin with a squeeze bar, at least so arranged that they are in contact with each other from the opposite side with respect to the running direction of the fiber bundle. By performing shaping with a shaping device including a pair of rollers, a fiber-reinforced thermoplastic resin material having high mechanical strength and using inorganic long fibers as a reinforcing material can be stably manufactured at high speed.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view showing one embodiment of a manufacturing apparatus of a long fiber reinforced thermoplastic resin molding material of the present invention.

FIG. 2 is a plan view showing the same embodiment.

FIG. 3 is a side view showing another embodiment of the shaping apparatus used in the apparatus for producing a long fiber reinforced thermoplastic resin molding material of the present invention.

FIG. 4 is a plan view showing the same embodiment.

FIG. 5 is a schematic view showing an example of a production process of a conventional long fiber reinforced thermoplastic resin molding material.

FIG. 6 is a cross-sectional view showing an example of an impregnation die used in a conventional apparatus for manufacturing a long fiber reinforced thermoplastic resin molding material.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 coating device 12 fiber bundle 14 thermoplastic resin 15 long fiber reinforced thermoplastic resin 16 cooling tank 17 take-off machine 18 squeeze bar 19 shaping device 20 inert gas atmosphere tank 21 resin inlet 22 impregnation tank 23 inlet 24 outlet 25, 29 Roller 27 Inert gas 28 bar

Claims (5)

[Claims] 1. A method for producing a long fiber reinforced thermoplastic resin molding material, in which a continuous inorganic fiber fiber bundle is impregnated with a molten thermoplastic resin, and then the thermoplastic resin is added to the fiber bundle. An impregnating step, and an excess resin by a squeeze bar consisting of at least one rod disposed above the resin surface of the molten thermoplastic resin and arranged to intersect the running direction of the fiber bundle. Squeezing, and shaping with a shaping device comprising at least a pair of rollers arranged so as to be in contact with each other from the opposite side with respect to the running direction of the fiber bundle. Manufacturing method of reinforced thermoplastic resin molding material. 2. The long fiber reinforced thermoplastic according to claim 1, wherein the step of impregnating the fiber bundle with the thermoplastic resin and the step of squeezing off the excess resin with the squeeze bar are performed under an inert gas atmosphere. Manufacturing method of resin molding material. 3. The method for producing a long fiber reinforced thermoplastic resin molding material according to claim 1, wherein the inorganic fibers are glass fibers. 4. A device for producing a continuous fiber-reinforced thermoplastic resin molding material by impregnating a continuous fiber bundle of a molten inorganic resin with a molten thermoplastic resin, and then injecting the thermoplastic resin. A resin inlet, an impregnation tank in which the thermoplastic resin is stored, an inlet for introducing the fiber bundle to the impregnation tank, an outlet for taking out the fiber bundle from the impregnation tank, and an outlet for this. A coating device having a squeeze bar composed of at least one rod arranged so as to intersect the traveling direction of the fiber bundle, and a traveling direction of the fiber bundle taken out of the coating device via the squeeze bar. And a shaping device including at least a pair of rollers arranged so as to contact with each other from opposite sides, respectively, for manufacturing a long fiber reinforced thermoplastic resin molding material. 5. The impregnation tank and the squeeze bar are covered with a tank into which an inert gas is introduced.
An apparatus for producing the long-fiber-reinforced thermoplastic resin molding material as described above.