JPH0584838A - Preparation of filament reinforced structure - Google Patents

Abstract

PURPOSE:To provide a high strength and stable product with improved uniformity of resin impregnation and a good surface with less fluffing by impregnating a resin into a fiber bundle without torsion and break in the process of drawing out the fiber bundle from a pakage-a hollow cylinder of reinforcing fiber bundle aggregate. CONSTITUTION:A rotary driving device is installed which rotates a table 6 according to the signal detected by a tension sensor. A hollow cylinder of a reinforcing fiber bundle aggregate 12 with a guide roller 10 penetrated into its void is placed on the table. The fiber bundle 26, being wound on the guide roller 10, is drawn out from the inner side of the hollow cylinder of the reinforcing fiber bundle aggregate 12 to the outside of the void. The tension generated in the fiber bundle 26 is detected by the tension sensor of the guide roller 10. The drawing out of the fiber bundle 26 is carried out while the table 6 being rotated intermittently or continuously in the backward direction to the unwinding direction of the fiber bundle 26 which is to be impregnated with a resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a resin structure reinforced with long fibers. More specifically, it is possible to effectively eliminate the twist of the fiber bundle that occurs when the fiber bundle is taken out from the reinforcing fiber bundle assembly that is wound into a coreless cylindrical shape by the internal feeding method, and impregnate this with a resin. Thus, the present invention relates to a method for producing a long fiber reinforced resin structure, which enables the uniform impregnation of a resin into a fiber bundle and the resulting production of a fiber reinforced resin structure having high strength and stable physical properties.

[0002]

2. Description of the Related Art A long fiber-reinforced resin structure in which a thermoplastic resin is reinforced with continuous fibers has much better mechanical properties than those reinforced with short fibers. Since it has the advantage that it can be cut into pellets or the like to have a molding material, it has been particularly expected in recent years. Such a long fiber-reinforced thermoplastic resin structure is generally impregnated with a thermoplastic resin while drawing a continuous reinforcing fiber bundle through a crosshead extruder, and then withdrawn through a die (US Pat. No. 399372).
No. 6), a continuous reinforcing fiber bundle is drawn, immersed in a molten thermoplastic resin to wet it, and then pulled out through a die (JP-A-57-181852). And is cut to an arbitrary length as desired.

On the other hand, a structure in which a thermosetting resin is used and which is reinforced with continuous fibers is also cured by coating a fiber such as glass roving with an uncured resin and then winding it around a rotating frame while applying tension. Various reinforcements are manufactured by a special method such as a so-called filament winding method, a preforming method for forming a prepreg in a semi-cured state, and a pultrusion method for shaping a deformed section and then completely curing it.

In the production of such a fiber-reinforced resin structure, whether a thermoplastic resin or a thermosetting resin is used, it is necessary that the continuous reinforcing fiber bundle is sufficiently impregnated with the matrix resin, Further, the uniform impregnation of the matrix resin is important not only from the mechanical properties but also from the appearance of the product. For this reason, generally, a method of opening the fiber bundle by passing it through a tension bar or a roll under tension and impregnating it with a resin in a molten state or a liquid is taken, but at this time, the fiber bundle is twisted. This causes insufficient opening of the fiber bundle and uneven impregnation associated therewith, and also causes breakage of the fibers in the fiber bundle opening process. The occurrence of such twist must be avoided.

By the way, in the production of the fiber reinforced resin structure as described above, a reinforced fiber bundle usually used has a diameter of 4 mm.
An assembly in which monofilaments of glass fibers, carbonized fibers, metal fibers, organic fibers and the like having a thickness of up to 25 μm are bundled with an appropriate sizing agent and flattened into a coreless cylindrical shape,
It is supplied as a so-called roving package.

There are two methods for taking out the fiber bundle from the package when taking out the fiber bundle from the package and impregnating it with the resin. The external removal method is a method of taking out the fiber bundle from the outer circumference of the package while rotating the package.It has the advantage that the fiber bundle is not twisted, but since a protective cover cannot be used for the package, the package cannot be used during transportation. It is easy to collapse, and the load on the extracted fiber bundle increases because the package itself rotates.
There is a problem that fluffing is likely to occur due to fiber breakage. Further, when the taken out fiber bundle separates from the package, a part of the fibers is likely to remain on the package side, and the unwinding property is poor.

On the other hand, the internal taking-in method is a method of taking out the fiber bundle from the inner peripheral side of the package, and the load applied to the taken-out fiber bundle is light, and a protective cover for preventing load collapse and contamination can be used, thus improving workability. Is considered a good method. Further, the unwinding property is also good. However, when the package is fixed and the fiber bundle is taken out from the inner circumference side, there is a disadvantage in that one twist is always added to the fiber bundle every time the fiber bundle is taken out once along the inner circumference of the package. As described above, the twisting of the fiber bundle is a cause of insufficient opening of the fiber bundle and accompanying insufficient and uneven impregnation of the resin in the production of the long fiber reinforced resin structure. In addition, it also causes breakage of fibers in the opening process and the like, which causes fuzzing. In such an internal arrangement method, in order to eliminate the twist of the fiber bundle, it is conceivable that the package itself is rotated once in the direction opposite to the fiber bundle rewinding direction every time one winding of the fiber bundle is taken out.
By placing the package on a rotatable table having a columnar or cylindrical protrusion in the center, and pulling out the fiber bundle while winding the fiber bundle around the columnar or cylindrical protrusion, A method of rotating the table and then the package by utilizing the frictional resistance of is possible, but this method requires a large load (tensile force) on the drawn fiber bundle, and the fiber breaks easily. Hard to say.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to manufacture a continuous fiber-reinforced resin structure in which a continuous reinforcing fiber bundle is drawn while impregnating a resin. By solving the above problems that occur when a fiber bundle is taken out from a bundle aggregate, that is, a package, and impregnating a fiber bundle without twists or breaks with a resin, it is possible to obtain excellent properties that are extremely close to the expected mechanical properties. It is to provide a method for efficiently producing a long fiber reinforced resin structure having a good surface condition and the like.

According to the present invention, an object of the present invention as described above is a table rotatably supported by an apparatus frame,
A guide roll protruding from the central part of the table, a tension sensor provided on the guide roll for detecting the tension of the fiber bundle applied to the guide roll, and a rotation driving means for rotating the table based on the signal detected by the tension sensor. Using a device having, while placing the reinforcing fiber bundle assembly wound in a coreless cylindrical shape on the table in a state where the guide roll penetrates the cavity, while winding the fiber bundle around the guide roll. The tension sensor of the guide roll detects the tension generated in the fiber bundle when unwinding from the inner circumference of the coreless cylindrical fiber bundle assembly to the outside of the cavity,
Based on the detection signal, the table is intermittently or continuously rotated in the direction opposite to the fiber bundle rewinding direction to continuously extract the fiber bundle, and the resin is impregnated while pulling the fiber bundle. This is achieved by a method of manufacturing a long fiber reinforced resin structure.

The present invention will be described in more detail below. There is no particular limitation on the type of reinforcing fiber used in producing the long fiber reinforced resin structure in the present invention, for example, a high melting point (high softening point) of glass fiber, carbon fiber, metal fiber, aromatic polyamide fiber, etc. Any fiber or the like can be used. These fibers may be treated with a known surface treatment agent. The present invention provides that such fibers are bundled,
The present invention relates to an improvement in a manufacturing method of a long fiber reinforced resin structure in which an aggregate wound in a coreless cylindrical shape, for example, a roving package is used, a fiber bundle is taken out from the inner peripheral side and impregnated with a resin. When taking out a fiber bundle from an assembly of reinforcing fiber bundles wound in a coreless cylindrical shape, a table rotatably supported by an apparatus frame, a guide roll protruding from the center of the table, and a guide roll Using a device having a tension sensor provided on the guide roll for detecting the tension of the fiber bundle and a rotation driving means for rotating the table based on the signal detected by the tension sensor, Take out the fiber bundle without touching it,
This is characterized by being impregnated with a resin. More specifically, an assembly of reinforcing fiber bundles wound into a coreless cylinder is placed on a table so that the guide roll penetrates through the hollow portion, and the fiber bundle is wound around the guide rolls. The bundle is taken out of the cavity from the inner peripheral portion. At this time, the guide roll receives a pressure such as a pulling force and a coiling force due to the tension generated in the fiber bundle, and this is detected by a sensor (tension sensor) provided on the guide roll.

The tension sensor converts the tension of the fiber bundle into another physical quantity on the guide roll and may be attached to the guide roll or the guide roll itself. For example, as shown in FIGS. 2 and 3, when the guide roll is elastically biased as a tension sensor in the upright direction and is tiltable in the fall direction according to the tension of the fiber bundle, the tension of the fiber bundle is Accordingly, the pulling force applied to the guide roll is detected by the inclination of the guide roll itself, which is a tension sensor. Further, as shown in FIG. 4, the guide roll is provided with an oscillating body elastically biased in the centrifugal direction on the side surface as a tension sensor, and the oscillating body can be tilted in the centripetal direction according to the tension of the fiber bundle. In the thing, the winding tightening force applied to the guide roll according to the tension of the fiber bundle is detected by the inclination of the oscillator. Further, as shown in FIGS. 5 and 6, the guide roll includes a plurality of divided side walls elastically biased in the centrifugal direction as tension sensors, and the divided side walls can be inclined in the centripetal direction according to the tension of the fiber bundle. In this case, the winding tightening force applied to the guide roll according to the tension of the fiber bundle is detected by the inclination of the divided side wall.

The tilt output of the tension sensor is used as a detection signal via displacement and other physical quantities as necessary. For example, the movable rod is inserted through the table rotation shaft so as to be displaceable in the axial direction, and the tension sensor movable portion, that is, the movable portion of the guide roll itself, the oscillating body, and the divided side wall is connected to the movable rod through the inclination-displacement conversion mechanism. In the case where the displacement sensor is installed on the movable rod when engaged, the tilt output of the tension sensor is converted into the displacement of the movable rod and transmitted in the axial direction of the table rotation shaft, and the displacement of the movable rod is detected by the displacement sensor. To be detected. Further, in the one provided with the tension sensor composed of the divided side wall, in the case where the displacement sensor is arranged on the central axis of the guide roll so as to face the divided side wall, the inclination output of the tension sensor is changed in the radial direction by the displacement sensor. Converted to the displacement of the dividing side wall. As the displacement sensor, for example, a capacitance type sensor that detects the displacement of the divided side wall by capacitance can be preferably used.

As described above, the tension applied to the fiber bundle is detected by the tension sensor provided on the guide roll, and is made a detection signal via another physical quantity as necessary, and the table is rotated based on the detection signal. The drive means is actuated to intermittently or continuously rotate the table in the direction opposite to the fiber rewinding direction (direction A in FIG. 7) (direction B in FIG. 7). The fiber bundle assembly placed on the table rotates together with the table. The table is rotated at an average of once every time the unwound fiber bundle is rewound along the inner circumference of the uncentered cylindrical fiber bundle assembly, whereby the twist generated in the fiber bundle is substantially eliminated. To be done.

As an example, the mechanism for eliminating the twist of the fiber bundle will be described by taking the apparatus shown in FIGS. The guide roll is provided with a tension sensor that is inclined by the tension applied to the fiber bundle and turned on and off at a specific tension (guide roll inclination), and the signal is used to operate the table rotation drive mechanism so that the table rotates once. It is assumed that it is set. Usually, when a fiber bundle is taken out from the inner peripheral side of a fiber bundle assembly wound in a coreless cylindrical shape, one twist is generated in the fiber bundle every time one roll is taken out along the inner circumference, and as it is, This twist cannot be eliminated.

On the other hand, when the above-mentioned device is used, the fiber bundle is wound around the guide roll once each time one winding of the fiber bundle is taken out along the inner circumference of the fiber bundle assembly, and the taken-out fiber bundle is taken out. Tension is generated in. This tension causes the guide roll to tilt, and when a certain specific tension, that is, when the guide roll has a particular tilt, the tension sensor operates, and the signal causes the table to rotate once in the direction opposite to the fiber bundle take-out direction. The tension is relieved, and the twist generated in the fiber bundle is eliminated once. If, for some reason, the fiber bundle is wound around the guide roll multiple times at a time, the tension sensor operates multiple times until the tension falls below the specific tension, and the tension is relieved by rotating the table multiple times, The twist that occurs in the fiber bundle is eliminated.

The fiber bundle extracted as described above without substantially twisting is preferably opened by a tension roll, a tension bar or the like and then impregnated with a resin. The impregnation method is not particularly limited, and any known impregnation method such as a method using an impregnation die or a method using an impregnation bath can be used.

In the present invention, the resin used for such impregnation may be either a thermoplastic resin or a thermosetting resin, and examples of the thermoplastic resin include polyethylene, polypropylene, polyethylene terephthalate and polybutylene terephthalate. Polyester, nylon 6, nylon 66, nylon 11, nylon 12, nylon
610, polyamide such as nylon 612, polyacetal,
Polycarbonate, thermoplastic polyurethane, polyphenylene sulfide, polyphenylene oxide, polysulfone, polyetherketone, polyetheramide,
Known thermoplastic resins such as polyetherimide or copolymers or modified products thereof, and examples of the thermosetting resin include unsaturated polyester, epoxy resin, thermosetting polyurethane, and the like, or prepolymers thereof. Can be mentioned. In particular, it is preferable that the obtained fiber reinforced structure is impregnated with a thermoplastic resin in terms of easy molding and processing,
Further, as an impregnation method therefor, it is preferable to use an impregnation die, particularly a crosshead die as shown in FIG. 1, from the viewpoint of operability.

Next, the continuous fiber impregnated with the resin is passed through a shaping die or the like into a desired shape such as a strand shape, a rod shape, a ribbon shape, a tape shape, a sheet shape, a plate shape, or a special shape. It is trimmed and picked up using a pick-up roll. The fiber-reinforced resin structure thus taken can be used as it is or after being cut to an arbitrary length and then subjected to molding or other processing.

The present invention is characterized by the method for producing a long fiber reinforced resin structure as described above, and the composition thereof, for example, the content of the reinforcing fiber is not particularly limited, but the structure obtained is obtained. From the viewpoint of various physical properties of the product, the compounding amount of the reinforcing fiber is preferably 20 to 80% by weight (in the composition), and particularly preferably 30 to 70% by weight (in the composition).

In addition, the long fiber reinforced resin structure obtained by the present invention contains various substances generally added to the resin, such as an antioxidant and a heat stabilizer, depending on the purpose and application.
Stabilizers such as UV absorbers, antistatic agents, lubricants, plasticizers, release agents, flame retardants, flame retardant aids, crystallization accelerators, coloring agents such as dyes and pigments, etc. It is also possible to mix an inorganic filler or an organic filler.

[0021]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

Examples 1 to 3 and Comparative Example 1 In preparing long fiber reinforced resin structures, the apparatus shown in FIG. 1 was used. As the device for taking out the fiber bundle from the fiber bundle assembly in FIG. 1, in Examples 1 to 3, the device for taking out the fiber bundle having the structure of FIGS. 2 to 6 was used. First, a glass roving package was used as the fiber bundle assembly, and when the roving was taken out by the internal take-in method, the roving was taken out in a non-twisted state by using the fiber bundle take-out device shown in FIGS. Next, after opening this glass roving with a tension roll, it is impregnated with a polypropylene resin while being drawn through a crosshead die, shaped with a die and taken out into a strand,
This was cut into 12 mm pellets. The fiber content is
It was adjusted to 40% by weight.

For comparison, the roving was taken out with the glass roving package fixed without using the fiber bundle take-out device as shown in FIGS. 2 to 6, and the polypropylene resin was impregnated into the twisted roving in the same manner and pelletized. I got a shape.

The evaluation was carried out by the following method, and the results are shown in Table 1. [Fluffing state of strands] The fluffing state of strands was observed with the naked eye. [Strand break (operation stop frequency)] The number of strand breaks during 5 hours of operation was measured. [Fiber Scattering in Pelletizer] The state of fiber scattering when the strand was cut and pelletized was observed. Non-uniform impregnation, poor adhesion between resin and fiber, and other factors result in increased fiber scattering. [Physical Properties] A pellet-shaped fiber reinforced structure was used to prepare a test piece by injection molding, and the physical properties were measured.

[0025]

[Table 1]

[0026]

As is apparent from the above description and examples, according to the method for producing a long fiber reinforced resin structure of the present invention, twisting is carried out from a reinforcing fiber bundle aggregate wound in a coreless cylindrical shape. It is possible to take out the fiber bundle without causing this, and by impregnating the fiber bundle with the resin, the impregnation property of the resin into the fiber bundle and the uniformity of the impregnation are significantly improved. As a result, it is possible to obtain a high-strength and stable physical-fiber-reinforced resin structure having less surface fluff and a good surface condition, and the method of the present invention is of extremely high industrial value.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of the entire manufacturing apparatus used in the present invention.

FIG. 2 is a vertical sectional view of a fiber bundle take-out device used in the present invention.

FIG. 3 is a longitudinal sectional view of a main part of the fiber bundle take-out device shown in FIG. 2 when a guide roll is inclined.

FIG. 4 is a vertical cross-sectional view of another example of the fiber bundle extracting device used in the present invention.

FIG. 5 is a vertical sectional view of still another example of the fiber bundle take-out device used in the present invention.

6 is a perspective view of a main part of a guide roll of the fiber bundle take-out device shown in FIG.

FIG. 7 is a plan view showing a relationship between a fiber bundle unwinding direction and a rotation direction of a fiber bundle aggregate (table).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fiber bundle take-out device 2 ... Roving package 3 ... Cross head die 4 ... Extruder 5 ... Device frame 6 ... Table 7 ... Table rotating shaft 8 ... Bearing 9 ... Followed pulley 10 ... Guide roll 12 ... Fiber bundle assembly (package ) 13 ... Movable rod 14 ... Spherical body 15 ... Clip 16 ... Slider 17 ... Clip 18 ... Bearing 19 ... Clip 20 ... Compression coil spring 21 ... Displacement sensor 22 ... Rotation control device 23 ... Motor 24 ... Driving pulley 25 ... Timing belt 26 ... Fiber bundle 27 ... Oscillator 28 ... Cam 29 ... Clip 30 ... Dividing side wall 31 ... Fixed rod 32 ... Displacement sensor 33 ... Amplifier

Claims (6)

[Claims] 1. A table rotatably supported by an apparatus frame, a guide roll projectingly provided in the center of the table,
Using a tension sensor provided on the guide roll for detecting the tension of the fiber bundle applied to the guide roll, and a device having a rotation driving means for rotating the table based on the signal detected by the tension sensor, a coreless cylinder is used. The reinforcing fiber bundle assembly wound in a circular shape is placed on the table in a state where the guide roll penetrates into the hollow portion, and the fiber bundle is wound around the guide roll from the inner circumference of the coreless cylindrical fiber bundle assembly. The tension generated in the fiber bundle when unwinding out of the cavity is detected by the tension sensor of the guide roll, and based on the detection signal, the table is intermittently or continuously rotated in the direction opposite to the fiber bundle rewinding direction and continuously. A method for producing a long-fiber-reinforced resin structure, characterized in that a fiber bundle is taken out of and the resin is impregnated while pulling the fiber bundle. 2. The guide roll is a tension sensor that is elastically biased in the upright direction and is tiltable in the fall direction according to the tension of the fiber bundle, and the tension of the fiber bundle is tilted by the inclination of the guide roll. The method for producing a long fiber reinforced resin structure according to claim 1, wherein the fiber bundle is taken out while detecting the temperature and rotating the table based on the detection signal. 3. The guide roll is provided with an oscillating body elastically biased in the centrifugal direction on the side surface as a tension sensor, and the oscillating body is capable of inclining in a centripetal direction according to the tension of the fiber bundle. The long fiber reinforced resin according to claim 1, wherein the winding tightening force applied to the guide roll according to the tension of the fiber bundle is detected by the inclination of the oscillating body, and the fiber bundle is taken out while rotating the table based on the detection signal. Structure manufacturing method. 4. The guide roll is provided with a plurality of divided side walls elastically biased in the centrifugal direction as a tension sensor, and the divided side walls are tiltable in a centripetal direction according to the tension of the fiber bundle. The long fiber reinforced resin according to claim 1, wherein the winding tightening force applied to the guide roll according to the tension of the fiber bundle is detected by the inclination of the divided side wall, and the fiber bundle is taken out while rotating the table based on the detection signal. Structure manufacturing method. 5. The method for producing a long fiber reinforced resin structure according to claim 1, wherein the reinforcing fiber bundle is impregnated with the resin using a crosshead die. 6. The long fiber reinforced resin structure is in the form of a strand,
A rod-shaped, ribbon-shaped, tape-shaped, sheet-shaped or plate-shaped or these are cut to an arbitrary length.
6. The method for producing a long fiber reinforced resin structure according to any one of 5 above.