JPH07276515A - Manufacture of long fiber reinforced resin structure - Google Patents

Abstract

PURPOSE:To prevent uneven impregnation of molten resin in the radial and peripheral directions of continuous fiber bundle from occurring by a method wherein the continuous fiber bundle is passed over die bending parts having the ridgeline, the angle between which of one die bending part contacting with the continuous fiber bundle and the width direction of a passage, the planar shape of which is a rectangle or square is the specified value. CONSTITUTION:A passage, which is provided in a crosshead die and the planar shape of the whole of which is a rectangle or square, is moved along the running direction in a vertical zigzag direction by the certain height. Continuous fiber bundle s continuously and drawingly passed over a passage, which is formed through the movement in a zigzag direction so as to have the respective straight ridge of a plurality of die bending parts. At the same time, molten resin is discharged in the passage so as to infiltrate the molten resin in the continuous fiber bundle during passing. At least one die bending part 20 having a ridgeline 21, in which the angle theta between the ridgeline of the die bending part and the width direction of the passage is 0-45 deg., is provided and the remaining die bending parts have the bending parts 22 and 23 having ridgelines, in each of which the angle between the ridgeline of the die bending part and the width direction of the passage is 0 deg., and their ridgeline 24 and 25.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a long fiber reinforced resin structure. More specifically, when impregnating a continuous fiber bundle with a molten resin using a crosshead die that is an impregnation die, the surface of the continuous fiber bundle passing through the die is renewed, and the impregnation state of the molten resin in the crosshead die is changed. The present invention relates to a method for producing a long fiber reinforced resin structure which is made more uniform.

[0002]

2. Description of the Related Art A long fiber reinforced resin structure consisting of a bundle of fibers arranged in parallel and a resin impregnated in the bundle is mainly manufactured in the form of long axis pellets, and various molded products requiring mechanical strength. Is used for. As the structure, typically, a continuous glass fiber bundle is passed through a passage in a crosshead die, and a molten resin is impregnated in the die, and then a desired shape is formed by a shaping die, for example, pellets as described above. It is shaped and manufactured. Such techniques are disclosed, for example, in U.S. Pat. No. 4,439,387 and Japanese Patent Laid-Open No. 3-272830.
It is disclosed in Japanese Patent Publication No.

[0003]

However, in the manufacturing method disclosed in the above document, the cross section of the continuous fiber bundle becomes flat to some extent due to the contact between the bent portion in the crosshead die and the continuous fiber bundle. However, the continuous fiber bundle does not substantially move in the direction perpendicular to the advancing direction of the continuous fiber bundle on the contact surface of the die bending portion, and therefore the fibers inside the continuous fiber bundle and the fibers on the surface are exchanged ( Surface renewal) was also insufficient. Therefore, there has been a problem that unevenness of impregnation of the molten resin occurs in the radial direction and the circumferential direction of the continuous fiber bundle. If there is such unevenness of impregnation of the molten resin, the fibers that make up the fiber bundle are broken during the manufacturing process due to the remaining unimpregnated fiber portion, leading to fluffing and finally causing thread breakage in the manufacturing equipment. In addition, it causes pills on the product pellets, and also causes quality defects on molded products made from such products.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies in order to solve the above problems in the production of long fiber reinforced resin structures in which a continuous resin bundle is passed through a crosshead die and impregnated with a molten resin. As a result, they have found that it is extremely effective to improve the shape of the die bending portion in the crosshead, the installation conditions, etc., and have reached the present invention.

That is, the first aspect of the present invention is a passage provided in the crosshead die and having a rectangular plane or a square shape as a whole, and the passage has a certain height in the vertical direction along the traveling direction. A continuous fiber bundle is continuously drawn while passing through a passage in which the ridge lines of a plurality of die bending portions that meander and are formed by the meandering are straight lines, and the molten resin is discharged into the passage while passing. In the method for producing a long fiber reinforced resin structure in which the continuous fiber bundle is impregnated with a molten resin, the angle θ formed by the ridgeline of at least one die bending portion in contact with the continuous fiber bundle and the width direction of the passage is 0. A method for producing a continuous fiber reinforced resin structure, characterized in that the continuous fiber bundle is passed through a die bending portion having a ridge line that exceeds more than 45 ° and is not more than 45 °. A second aspect of the present invention is a passage in which the entire planar shape provided in the crosshead die is a rectangle or a square, and the passage meanders at a constant height in the vertical direction along the traveling direction thereof, In a method for producing a continuous fiber reinforced resin structure, which allows a continuous resin bundle to pass through the passage while being continuously drawn out, and a molten resin is discharged into the passage, and the continuous fiber bundle that is passing is impregnated with the molten resin. Formed by the meander,
Each ridge line of at least two die bent portions that are adjacent to and in contact with one continuous fiber bundle is a polygonal line shape, and an angle θ between each polygonal line segment and the width direction of the passage is more than 0 ° and 45 ° or less. And a die having a polygonal ridge line such that the angle θ formed by two polygonal ridge lines that are adjacent to each other and in contact with one continuous fiber bundle and the width direction of the passage are formed in mutually opposite directions. A method for producing a long fiber reinforced resin structure, characterized in that a continuous fiber bundle is passed through a bent portion. A third aspect of the present invention is a passage provided in the crosshead die and having a rectangular planar shape as a whole, and the passage meanders in the vertical direction along its traveling direction, and is formed by the meandering. While passing the continuous fiber bundle while continuously pulling out the continuous fiber bundle into the passage in which each ridge line of the plurality of die bending portions is a straight line, the molten resin is discharged into the passage, and the molten resin is passed through the continuous fiber bundle during passage. In the method for producing a long fiber reinforced resin structure to be impregnated, the continuous fiber bundle is passed through a die bent portion having at least one ridge line of the die bent portion that is in contact with the continuous fiber bundle. It is a manufacturing method of a resin structure. Further, a fourth aspect of the present invention is to pass the continuous fiber bundle while continuously pulling out the continuous fiber bundle into a crosshead die having a horizontal passage or a vertically meandering passage, and to discharge the molten resin into the passage so that the continuous fiber bundle during the passage. In the method for producing a long fiber reinforced resin structure in which a fiber bundle is impregnated with a molten resin, at least one of the upper inner surface or the lower inner surface of the passage is provided with a large number of irregular portions that randomly contact the continuous fiber bundle, A method for producing a long fiber-reinforced resin structure, which comprises passing a continuous fiber bundle.

[0006]

According to the present invention, the ridge line is inclined with respect to the traveling direction of the passage, or the ridge line has a slope or a passage portion in which a large number of irregular portions are randomly provided is provided. By passing the continuous fiber bundle, a force is exerted on the contact surface of the die bending portion and the uneven portion in the direction perpendicular to the traveling direction, as a result, the surface update of the fiber bundle is promoted and the impregnation of the molten resin is facilitated. Therefore, the uniform impregnation of the molten resin in the radial direction and the circumferential direction of the fiber bundle is improved.

Hereinafter, the present invention will be described in more detail with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 illustrates the outline of the whole manufacturing process used in the method for manufacturing a long fiber reinforced resin structure of the present invention. In the figure, the continuous fiber bundle 2 is pulled out from the roving 1. As the continuous fiber bundle 2, for example, glass fiber, carbon fiber, metal fiber, high melting point fiber such as aromatic polyamide fiber, or the like, or a combination thereof can be used, and continuous fiber such as roving and yarn can be used. The drawn continuous fiber bundle 2 is guided to the inlet 6 of the passage 5 of the crosshead die 3. The continuous fiber bundle 2 is preferably defibrated before being introduced into the crosshead die 3.
By appropriately setting the defibration condition, the defibration degree of the continuous fiber bundle can be controlled from the undefibrated state to a sufficient defibrated state, but it is preferable to defibrate more sufficiently.

In the crosshead die 3, a passage 5 having a rectangular or square planar shape as a whole is formed in the upper and lower substantially central portions of the die 3. In FIG. 1, only one continuous fiber bundle 2 is shown in the crosshead die 3, but in reality, many continuous fiber bundles 2 are arranged in parallel in the depth direction (same as the width direction of the passage) perpendicular to the drawing. It is possible to pass through and impregnate them at the same time. The passage 5 is linear near the passage entrance 6, but meanders vertically from the middle. The meandering order in the vertical direction is not particularly limited.
The molten resin is discharged and supplied to the discharge position 4 ′ in the passage via the molten resin supply passage 4, and the continuous fiber bundle is impregnated with the molten resin while passing through the passage in the crosshead die 3. Although the molten resin is supplied from the upper side in FIG. 1, it may be supplied from the lower side, and the molten resin supply passage 4 may be provided at a plurality of locations.

The continuous fiber bundle 2 impregnated with the molten resin passes through the passage outlet 7 through the crosshead die 3, is taken up by the take-up roll 8 and is made into pellets 10 by the pelletizer 9.

FIG. 2 is a first explanatory view of the present invention.
FIG. 2 (A) is a partial cross-sectional view of a lower die split mold, in which a crosshead die is separated in a die passage, taken along a plane perpendicular to the traveling direction of the passage, and FIG. 2 (B) shows only the position of the ridge line. FIG. 3 is a plan view of FIG. In both cases, the line of the valley bottom of the die bending portion is omitted. The figure shows only one die bent portion (hereinafter referred to as an inclined bent portion) 20 having a ridge line 21 such that an angle θ formed by the ridge line of the die bent portion and the width direction of the passage is more than 0 ° and not more than 45 °. The remaining portion shows a case in which the bent portions 22 and 23 and the ridge lines 24 and 25 of which the angle formed by the ridge line of the die bent portion and the width direction of the passage is not inclined are provided. The angle θ formed between the ridgeline of the inclined bent portion and the passage width direction is preferably in the range of 1 to 30 °, preferably 1 to 30 °.
It is in the range of 20 °, particularly preferably in the range of 1-10 °. Further, such an inclined bent portion may be provided on the upstream side of the passage with respect to the molten resin discharge position 4 ′ shown in FIG. 1, but is preferably provided on the downstream side (the side near the passage outlet 7).

FIG. 2 (C) shows a first preferred embodiment of the present invention, in which the ridge lines of at least two die bent portions which are in contact with one continuous fiber bundle adjacent to each other and the width direction of the passage. The continuous fiber bundle is passed through a die bending portion having ridges such that the formed angles θ are more than 0 ° and not more than 45 °, and the plurality of angles θ are formed in directions opposite to each other with respect to the traveling direction of the passage. The following shows the case of making it. FIG. 2 (C) is a plan view showing only the positions of the ridge lines of the die bending portions that come into contact with the upper and lower die split type continuous fiber bundles.
When 6 is, for example, the ridge line of the lower die split mold, 27 is the ridge line of the upper die split mold, and 28 is the ridge line of the lower die split mold. When one continuous fiber bundle passes through the inclined bent portions of 26, 27, and 28, on the bent portion surface perpendicular to the traveling direction,
This causes a surface renewal due to the forces acting to move in opposite directions.

FIG. 3 shows a second embodiment of the present invention, which is a modification of the first preferred embodiment, in which each ridge line of at least two die bent portions which are in contact with one continuous fiber bundle next to each other. Is a polygonal line, and the angle θ formed between each polygonal line segment and the width direction of the passage is more than 0 ° and 45 ° or less, and further two polygonal line ridges that are adjacent to and contact one continuous fiber bundle. The continuous fiber bundle is characterized in that the continuous fiber bundle is passed through a die bending portion having a polygonal ridge line such that an angle θ formed between each portion and the width direction of the passage is formed in opposite directions. Similarly to FIG. 2 (C), FIG. 3 is a plan view showing only the positions of the ridge lines of the die bending portions that come into contact with the upper and lower die split type continuous fiber bundles. For example, when the ridge line of the lower die split mold is used, 30 is the ridge line of the upper die split mold, and 31 is the ridge line of the lower die split mold. When one continuous fiber bundle passes through the inclined bent portion having the ridgelines 29, 30, 31, a force acts to move in opposite directions on the bent portion surface perpendicular to the traveling direction, so that the surface renewal is performed. Is done. It is preferable that these inclined bent portions are installed on the downstream side of the passage (the side closer to the passage outlet 7) than the molten resin discharge position 4'shown in FIG.

In a third method for producing a long fiber reinforced resin structure according to the present invention, the entire planar shape provided in the crosshead die is a rectangular or square passage, and the passage is along the traveling direction. Meandering in the vertical direction, and passing the continuous fiber bundle continuously while pulling out the continuous fiber bundle through a passage in which the ridge lines of the plurality of die bends formed by the meandering are linear, and discharging the molten resin into the passage. In the method for producing a long fiber reinforced resin structure in which the continuous fiber bundle being passed through is impregnated with a molten resin, at least one die bend portion in contact with the continuous fiber bundle has a ridge line having a slope (hereinafter, It is characterized in that a continuous fiber bundle is passed through a bent portion having a ridge gradient.

In FIG. 4, the crosshead die is separated by the passage of the die, and the bent portions 32, 33, 34, 35 having a ridge gradient in the lower die split mold of the passage have gradients in opposite directions. The case where they are provided next to each other is shown. FIG. 4 (A) is a partial sectional view of the lower die split mold, and FIG. 4 (B) shows only the positions of the sloped ridgelines 36, 37, 38, 39 of FIG. 4 (A). It is a top view. In this case, the upper die split mold is also similar to the lower die, but it is preferable that the upper die split mold be composed of a bent portion having a ridge gradient so that both can be fitted to form a passage. The gradient is preferably in the range of 1 to 30 °, more preferably in the range of 1 to 20 °, and particularly preferably in the range of 1 to 10 °. Further, it is preferable that such a bent portion having a ridge slope is installed on the downstream side of the passage (closer to the passage outlet 7) than the molten resin discharge position 4'shown in FIG. By passing through a bent portion having such a ridge gradient, preferably by passing through a plurality of bent portions having a ridge gradient,
Surfaces of the continuous fiber bundles are renewed because the forces acting to move the continuous fiber bundles in the directions perpendicular to the traveling direction are opposite to each other.

A fourth method for producing a long fiber reinforced resin structure according to the present invention is characterized in that at least one of the upper and lower inner surfaces of the passage is provided with a large number of uneven portions randomly contacting the continuous fiber bundle at the passage portion. It is characterized by passing a continuous fiber bundle. The passage in which the uneven portions are randomly provided may be a crosshead die in which the passage is horizontal or a crosshead die in which the passage meanders vertically. In the latter case, the uneven portion may be installed at a position where the passage is horizontal or at a bent portion due to meandering. The shape of each concavo-convex portion may be a smooth mountain shape or a sharp mountain shape like the surface of a radish grater.

FIG. 5 is a perspective view showing a state in which the crosshead die is separated in the passage of the die, and the concavo-convex portion is randomly provided in the horizontal portion of the lower die splitting die of the passage, and the continuous fiber bundle is passing through. Indicates. By passing the continuous fiber bundle through such an uneven portion, the continuous fiber bundle comes into contact with an inclined surface of the uneven portion and advances in zigzag, so that the surface is renewed.

As the resin with which the continuous fiber bundle 4 is impregnated,
Not only the thermoplastic resin but also the thermosetting resin before curing may be used, but the former is preferable. For example, polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate and polybutylene terephthalate, polyamide such as nylon 6, nylon 66, nylon 11, nylon 12, nylon 610 and nylon 612, polyacetal, polycarbonate, polyurethane, polyphenylene sulfide, polyphenylene oxide. , Other thermoplastics such as polysulfones, polyetherketones, polyetheramides, polyetherimides, and combinations thereof can be used. The molecular weight of these resins is not particularly limited as long as it exhibits an appropriate fiber reinforcing effect when impregnated into fibers.
These resins include various additives such as an antioxidant, an antistatic agent, a lubricant, a plasticizer, a release agent, a flame retardant, a flame retardant aid, and a crystal, depending on the use of the resin structure and the use conditions. An accelerating agent, a coloring agent and the like can also be added.

[0019]

As is apparent from the above, according to the method for producing a long fiber reinforced thermoplastic resin structure of the present invention, the surface of the fiber bundle is renewed when the continuous fiber bundle passes through the crosshead die. As a result, it is excellent in uniform impregnation with molten resin, can prevent fiber breakage, fluffing, yarn breakage, etc., and prevents the formation of pills in pellets, and also in terms of the quality of molded products made from such pellets. It has become possible to suppress the occurrence of defects.

[Brief description of drawings]

FIG. 1 is a schematic view of the entire manufacturing process used in the method for manufacturing a long fiber reinforced resin structure of the present invention.

FIG. 2 shows a sectional front view (A) and a plan view (B) of a part of a split mold when an inclined and bent portion is provided in a crosshead die. (C) shows another embodiment.

FIG. 3 is a plan view of a split mold in another case in which an inclined bending portion is provided in the crosshead die.

FIG. 4 is a front view and a plan view of a split mold in which a bent portion having a ridge gradient is provided in a crosshead die.

FIG. 5 is a perspective view of a split mold when uneven portions are randomly provided in the crosshead die.

[Explanation of symbols]

 2 continuous fiber bundle 3 cross head die, 4 molten resin supply path 4'molten resin discharge position 5 passage 6 passage inlet 7 passage outlet 20 inclined bent portion 21 inclined curved edge line 26 to 31 inclined curved edge line 32 to 35 edge line Bent section with slope 36-39 Ridge line with slope 40 Concavo-convex section

Claims (9)

[Claims] 1. A passage having a rectangular or square shape in a plan view provided in a crosshead die, the passage meandering vertically at a constant height along the traveling direction thereof, and Each of the ridges of the plurality of die bending portions to be formed is passed through the passage having a straight line while continuously drawing the continuous fiber bundle, and the molten resin is discharged into the passage to the passing continuous fiber bundle. In a method for producing a long fiber reinforced resin structure impregnated with a molten resin, an angle θ formed by a ridgeline of at least one die bending portion in contact with a continuous fiber bundle and a width direction of the passage exceeds 0 ° and is 45 ° or less. The continuous fiber bundle is passed through a die bending portion having a ridgeline such that 2. The angle θ formed by the ridgelines of at least two die-bending portions adjacent to and in contact with one continuous fiber bundle and the width direction of the passage is more than 0 ° and not more than 45 °, and said θ The continuous fiber reinforced resin structure according to claim 1, wherein the continuous fiber bundle is passed through a die bending portion having ridges such that the ridges are formed in directions opposite to each other with respect to the traveling direction of the passage. Manufacturing method. 3. A cross-shaped die provided in the crosshead die and having a rectangular planar shape as a whole, and the passage meanders vertically at a constant height along the traveling direction of the passage. While continuously pulling out the continuous fiber bundle while discharging the molten resin into the passage,
In the method for producing a continuous fiber reinforced resin structure in which the continuous fiber bundle being passed is impregnated with a molten resin, each of at least two die bent portions formed by the meandering and contacting one continuous fiber bundle next to each other. The ridge line is a polygonal line, and the angle θ formed by each polygonal line segment and the width direction of the passage is more than 0 ° and 45 ° or less, and further, two polygonal lines that are adjacent to and contact one continuous fiber bundle. A long fiber reinforced resin structure characterized in that a continuous fiber bundle is passed through a die bending portion having a polygonal ridge line such that an angle θ formed by the ridge lines and the width direction of the passage is formed in mutually opposite directions. Manufacturing method. 4. The method for producing a long fiber reinforced resin structure according to claim 1, wherein the angle θ is in the range of 1 to 10 °. 5. A die bent portion having a ridgeline such that the angle θ is more than 0 ° and not more than 45 ° is installed on the downstream side of the passage from the discharge position of the molten resin. 5. The method for producing a long fiber reinforced resin structure according to any one of 4 to 4. 6. A cross-shaped die having a rectangular or square overall planar shape provided in the crosshead die, wherein the passage meanders vertically along its traveling direction, and a plurality of passages formed by the meandering are formed. A continuous fiber bundle is continuously drawn while passing through a passage in which each ridge line of the die bending portion is a straight line, and molten resin is discharged into the passage to impregnate the continuous fiber bundle that is passing through with the molten resin. In the method for producing a fiber-reinforced resin structure, the continuous fiber bundle is passed through a die bending portion having at least one ridge line of the die bending portion having a slope in contact with the continuous fiber bundle. Manufacturing method. 7. The continuous fiber bundle is passed through a die bent portion having at least two ridges of the die bent portions which are adjacent to and in contact with one continuous fiber bundle and have gradients in mutually opposite directions. 6. The method for producing a long fiber reinforced resin structure according to 6. 8. The method for producing a long fiber reinforced resin structure according to claim 6, wherein a die bent portion having a ridge with a slope is installed downstream of the passage of the molten resin. . 9. A continuous fiber bundle is continuously drawn while passing through a crosshead die having a horizontal passage or a vertically meandering passage, and molten resin is discharged into the passage so that the continuous fiber bundle is passing through. In the method for producing a long fiber reinforced resin structure impregnated with a molten resin, at least one of the inner surface of the upper side of the passage or the inner surface of the lower side is provided with a large number of irregularities randomly contacting the continuous fiber bundle, and the continuous fiber bundle. A method for producing a long fiber reinforced resin structure, characterized in that