JPH1128755A - Production of tubular object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reinforce a tubular object by arranging a reinforcing material in both longitudinal and peripheral directions of the tubular object, in a mold consisting of the rotary cylindrical middle mold inside a cylindrical mold and the rotary inner mold inside the middle mold, by melting and mixing a reinforcing material and thermoplastic resin to pass the resulting mixture through the annular passage between the outer mold and middle mold of the mold and the annular passage between the middle mold and inner mold thereof to allow them to meet with each other in a mold annular confluent passage part to laminate them to extrude the laminate in a tubular form. SOLUTION: The molten mixture containing a reinforcing material and a thermoplastic resin melted and mixed in an extruder is introduced into an extrusion mold 12 from a resin passage 28. The molten mixture is separately introduced into the annular passage A between an outer mold 22 and a middle mold 23 and the annular passage B between the middle mold 23 and an inner mold 24 from the through-holes provided on the circumference of the middle mold 23 at an equal interval to be passed therethrough and allowed to meet with each other in the annular confluent passage part of a mold 12 to be laminated to form a tubular laminated shaped article and a tubular object T is extruded from a mold outlet. The outer layer (a) of the wall thickness of the tubular object T becomes a layer wherein the reinforcing material is oriented in the annular passage A and the inner layer (b) becomes a layer wherein the reinforcing material is oriented in the annular passage B. By this constitution, the tubular member wherein the reinforcing material is oriented in both of peripheral and axial directions is obtained and the tubular member excellent in inner and outer strengths can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a tubular body made of a thermoplastic resin reinforced by a reinforcing material.

[0002]

2. Description of the Related Art Conventionally, in order to increase the strength of a synthetic resin tubular body, a fibrous reinforcing material has been mixed.

However, according to the conventional method, since the fibrous reinforcing material is oriented in the extrusion direction, the fiber is reinforced in the extrusion direction, that is, in the longitudinal direction of the tubular body, but is not reinforced in the circumferential direction of the tubular body. There was a disadvantage.

In order to solve such a drawback, for example, as described in Japanese Utility Model Application Laid-Open No. 61-71421, a nipple (inner die) and a die (outer die) provided coaxially with the nipple are disclosed. And a method for obtaining a tubular body in which short fibers are oriented in the circumferential direction by extrusion molding using a mold in which one of a nipple and a die is rotationally driven.

If it is desired to obtain a reinforced tubular body in both the circumferential direction and the longitudinal direction, it is conceivable to use a two-layer flow channel incorporating each method.

[0006]

However, when this method is adopted, at the portion where the two layers join, the molten resin which is rotated by the mold and flows in the circumferential direction and the fixed flow path surface are moved in the longitudinal direction. Since the flowing molten resin is laminated, there is a problem that reinforcement in the tube circumferential direction and the longitudinal direction is insufficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to reinforce the material in both the longitudinal direction and the circumferential direction of the tubular body so that both are efficiently reinforced. An object of the present invention is to provide a method for manufacturing a tubular body, which can form the tubular body.

[0008]

In order to achieve the above object, a method for manufacturing a tubular body according to the present invention comprises a substantially cylindrical outer mold, and an outer mold which is housed inside the outer mold and has the same direction as the resin extrusion direction. A substantially cylindrical middle mold that is driven and rotated around a rotating shaft extending therethrough, and an inner cylinder that is housed inside the middle mold and is driven and rotated at the same rotational speed in the same direction as the middle mold about a rotating shaft that extends in the same direction as the resin extrusion direction. A mold having a mold is prepared, an annular flow path (hereinafter, referred to as an annular flow path) is formed between the outer mold and the middle mold, and an annular flow path is formed between the middle mold and the inner mold. While being formed, these annular flow paths are joined at the outlet side of the mold to form an annular combined flow path portion, and the molten mixture containing the reinforcing material and the thermoplastic resin melt-mixed in the extruder is formed. ,
The molten mixture is introduced into the plurality of annular flow paths of the mold, the molten mixture is passed through these flow paths, and the molten mixture that has passed through each annular flow path at the annular merging flow path section of the mold is merged and laminated. Thus, a tubular laminated shape is formed and extruded from a mold outlet.

In the above method for manufacturing a tubular body, the outer mold may be
With the rotation axis extending in the same direction as the resin extrusion direction,
In addition, the difference in the number of rotations is 1 in the same
It is preferable to drive and rotate at rpm or higher, or to drive and rotate in a different direction from the middle and inner molds.

Further, the method for producing a tubular body of the present invention comprises a substantially cylindrical outer mold which is driven and rotated about a rotating shaft extending in the same direction as the resin extrusion direction; Prepare a mold that has a substantially cylindrical middle mold that is driven and rotated at the same rotation speed in the same direction as the outer mold about the rotation axis extending in the same direction as the extrusion direction, and an inner mold housed inside the middle mold. An annular flow path is formed between the outer mold and the middle mold, an annular flow path is formed between the middle mold and the inner mold, and these annular flow paths join at an outlet side portion of the mold to form an annular flow path. A merging flow path is formed, and a molten mixture containing a reinforcing material and a thermoplastic resin melt-mixed in an extruder is introduced into a plurality of annular flow paths of a mold, and the molten mixture is flown into these flow paths. And the molten mixture that has passed through each annular channel at the annular merging channel of the mold Confluence and then stacked to form a tubular laminate excipients thereof, and wherein this extruding from the die outlet.

In the above method for manufacturing a tubular body, the inner mold may be:
With the rotation axis extending in the same direction as the resin extrusion direction,
And a difference in the number of rotations in the same direction as the rotation direction of the middle and outer molds is 1
It is preferable to drive and rotate at rpm or higher, or to drive and rotate in a different direction from the middle and outer molds.

(1) Reinforcing Material Examples of the reinforcing material used in the present invention include a reinforcing fiber and a liquid crystal polymer which becomes fibrous when subjected to a shearing force in a fluidized state.

As the reinforcing fibers, those which do not melt soften and carbonize by the heat applied in the production process of the present invention can be used. Specifically, glass fibers, carbon fibers, metal fibers, or aramid fibers, Polyester fiber,
And organic fibers such as polyamide fibers, or silk, cotton,
Or natural fibers such as hemp.

When a reinforcing fiber is used as the reinforcing material, the reinforcing fiber may be a monofilament or a strand in which a plurality of monofilaments are bundled. Further, the form at the time of supply to the extruder may be a monofilament form, a chopped strand form, or a roving form.

As for the dimensions of the reinforcing fibers, the aspect ratio (reinforcing fiber length / reinforcing fiber diameter) is preferably 5.0 or more. When the aspect ratio is 5.0 or less, the reinforcing effect by the fiber is small. Since the strength in the circumferential direction increases as the length of the reinforcing fibers in the obtained tubular body increases, continuous fibers may be used.

As the liquid crystal polymer, any polymer having a liquid crystal transition temperature higher than the softening temperature of a thermoplastic resin described later and becoming fibrous by a shear force applied in a fluidized state can be used. Examples include wholly aromatic liquid crystal polyesters and semi-aromatic liquid crystal polyesters.

When a liquid crystal polymer is kneaded with a thermoplastic resin at a temperature equal to or higher than the liquid crystal transition temperature, it can be fiberized by shearing. As dimensions of the fibrous liquid crystal polymer, the aspect ratio (fiber length / fiber diameter) is preferably 5.0 or more.

The reinforcing material is contained in the mixture of the reinforcing material and the thermoplastic resin in the range of 1 to 80% by volume, and particularly preferably in the range of 2 to 50% by volume. When the content is less than 1% by volume, the reinforcing effect is small, and when the content is more than 80% by volume, the amount of resin binding between the reinforcing materials is small, so that the tubular body is weak.

Fillers such as talc, mica, calcium carbonate, wood powder, crushed synthetic resin powder, and crushed fiber reinforced synthetic resin powder are used as long as the reinforcement of the thermoplastic resin by the reinforcing material is not hindered. You may mix.

(2) Synthetic Resin The thermoplastic resin used in the present invention is not particularly limited as long as it can be molded into a tubular body by extrusion.
Examples include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyvinylidene fluoride, polyphenylene sulfide, polyphenylene oxide, polyether sulfone, polyether ether ketone, polymethyl methacrylate, and the like. Further, a copolymer or a graft resin containing the above synthetic resin as a main component, for example, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, vinyl acetate-
Ethylene copolymer, vinyl acetate-vinyl chloride copolymer,
Urethane-vinyl chloride copolymer, acrylonitrile-butadiene-thretin copolymer, acrylonitrile-styrene copolymer, silane-modified polyethylene, maleic acid-modified polyethylene, acrylic acid-modified polypropylene, maleic acid-modified polypropylene, and the like can also be used. Further, rubber, elastomer and crosslinkable resin can also be used.

Considering the molding temperature, 120-250 ° C.
Polyethylene, which can be molded at relatively low temperatures such as
It is preferable that the main component be polypropylene, polyvinyl chloride, polystyrene, acrylonitrile-butadiene-retin copolymer, or the like.

The synthetic resin used in the present invention may be used alone or in combination.
Alloy resins can also be used.

The synthetic resin may contain additives such as a heat stabilizer, a lubricant, a processing aid, a plasticizer, an antioxidant, an ultraviolet absorber, a modifier, and a colorant.

(3) Mixing of Reinforcement and Synthetic Resin The mixing of the reinforcing material and the synthetic resin may be performed in advance using a mixer or a tumbler, or may be quantitatively supplied to an extruder, and the mixture may be mixed in the extruder. You may mix.

When supplying the extruders to each other, the reinforcing material and the synthetic resin may be supplied from separate supply units. For example, the synthetic resin may be supplied from an extruder hopper, and the reinforcing material may be supplied in the middle of a screw of the extruder.

Further, a synthetic resin containing a reinforcing material in advance may be used. For example, the reinforcing material and the synthetic resin may be kneaded and pelletized with an extruder or the like, or the synthetic resin may be melt-infiltrated between monofilaments of the fibrous reinforcing material.

The state of the synthetic resin or the synthetic resin containing the reinforcing material when supplied to the extruder may be in the form of pellets or powder, or may be in the state of being once melted by another kneading melter or the like. May be supplied.

[0028]

Next, an embodiment of the present invention will be described.
This will be described with reference to the drawings.

Referring first to FIG. 1, an apparatus for producing a tubular body used in the present invention comprises an extruder (11) and an extrusion die (1).
2) a water tank (13) as cooling means, and a take-off machine (14).

Next, referring to FIG. 2, the extrusion die (12)
Is the outermost jacket type (21) and the substantially cylindrical outer type (22)
And a substantially cylindrical middle mold (23) that is housed inside the outer mold (22) and driven and rotated about a rotation shaft extending in the same direction as the resin extrusion direction, and housed inside the middle mold (23) and An intermediate mold (23) and an inner mold (24) that is driven and rotated at the same rotational speed in the same direction are provided around a rotating shaft extending in the same direction as the resin extrusion direction.

An annular flow path (A) is provided between the outer mold (22) and the middle mold (23).
Is formed, an annular flow path (B) between the middle mold (23) and the inner mold (24).
Are formed, and these annular flow paths (A) and (B) are joined at the outlet side portion of the mold (12) to form an annular combined flow path portion.

That is, the mold (12) used in the present invention forms a double annular flow path by at least a triple mold, of which the double mold is driven and rotated at the same rotational speed in the same direction. The remaining one mold is not driven or rotated at a rotational speed having a difference of 1 rpm or more from the other two molds.

The illustrated one has a structure in which an outer mold (22), a middle mold (23) and an inner mold (24) are all driven and rotated by drive motors (25), (26) and (27).

The driving speed of each type is not particularly limited, but is preferably about 1 to 1000 rpm. 1r
If it is less than pm, the reinforcing material is not sufficiently oriented, and 1000 r
If it is not less than pm, the heat generated by shearing of the synthetic resin becomes excessive, making the production difficult.

According to the second and fourth aspects of the present invention, the rotation directions of the outer mold and the inner mold may be the same as or different from those of the two molds rotating at the same rotational speed in the same direction.
When rotating in the same direction, the number of rotations that affects the molten mixture is the number of rotations obtained by subtracting the smaller number of rotations from the larger number of rotations.
It is preferably about 000 rpm. If it is less than 1 rpm, the reinforcing material is not sufficiently oriented, and if it is more than 1000 rpm, heat generation due to shearing of the synthetic resin becomes excessive, and production becomes difficult.

The driving rotation of each type may be provided on at least a part of the flow path surface of the type forming the annular flow path.
In order to reduce the relaxation of the orientation of the reinforcing material due to the rotation, it is better to be provided on the downstream side with respect to the extrusion direction as much as possible. Further, for the same reason, it is preferable that the annular merging flow path is provided as much as possible on the downstream side.

The axial length (Lr) of the drive rotating part constituting the flow path is such that Lr / Dr is 1 or more with respect to the flow path gap (Dr) of the drive rotating part. And more preferably 5 or more. When Lr / Dr is less than 1, the reinforcing material is not sufficiently oriented.

In the inventions according to claims 2 and 4,
The axial lengths of the outer and inner dies, which are driven and rotated, may be the same or different from those of the two dies rotating at the same rotation speed in the same direction. Since the state is disturbed, it is preferable not to drive and rotate.

The flow path surface other than the portion which is driven and rotated may be constituted by a fixed mold, or may be constituted by an unfixed non-driven rotation type which does not rotate but can rotate freely. .

According to the method for producing a tubular body according to the present invention,
Referring to FIGS. 1 and 2, a molten mixture containing a reinforcing material and a thermoplastic resin melt-mixed in an extruder (11) is passed through a resin passage.
(28), introduced into the extrusion mold (12), and through the through holes provided at equal intervals on the circumference of the middle mold (23), an annular flow path between the outer mold (22) and the middle mold (23). (A) and into the annular flow path (B) between the middle mold (23) and the inner mold (24) .The molten mixture is passed through these flow paths, and the annular merge of the mold (12) is performed. The molten mixture that has passed through each of the annular flow paths in the flow path section is merged and laminated to form a tubular laminated molded article, which is formed into a tubular body (T) from a mold outlet.
It extrudes. At this time, during the thickness of the tubular body (T), the outer layer (a) becomes a layer in which the reinforcing material is oriented in the annular flow path (A), and the inner layer (b) has the reinforcing material oriented in the annular flow path (B). Layer.

In the above, as the extruder (11), a molding device capable of melting, kneading and extruding a synthetic resin, such as a single screw extruder or a twin screw extruder, can be used. Here, inner mold (24)
As means for rotating the screw, the screw of the single screw extruder and the inner mold may be integrated, and the rotation of the screw may be the rotation of the inner mold.

The tubular body (T) extruded from the mold (12) is
As with normal extrusion molding, while taking off with the take-off machine (13),
Cooling and shaping may be performed, but when the tubular body (T) is extruded from the mold (12) while rotating, a device capable of taking up, cooling and shaping while rotating is required.

As a method of cooling and shaping the tubular body, a method of passing a liquid or a gaseous refrigerant while maintaining the outer shape or the inner shape in a desired shape, or a cooling metal having a desired shape through which the refrigerant has passed is used. There is a method of pressing against a mold and the like, and it is appropriately selected according to the dimensions and use of the product.

(Function) In the method for producing a tubular body of the present invention, preferably, a mixture containing a reinforcing material and a synthetic resin is formed into an annular flow path constituted by two molds driven and rotated at the same rotational speed in the same direction. And the other one mold is not driven and rotated, or passes through an annular flow path composed of one mold that is rotated at a rotation speed having a difference of 1 rpm or more from the other two molds,
The former annular flow path is characterized in that it is oriented in the extrusion direction, that is, the axial direction, and the latter annular flow path is circumferentially oriented, and then merged and extruded.

According to the method of the present invention, the annular flow path in which both the inner mold and the outer mold are driven and rotated at the same rotational speed in the same direction is the same as the relatively fixed annular flow path, and the reinforcing material is tubular. It is oriented in the body axis direction, and at the confluence, merges in the same flow state as the molten mixture in which the reinforcing material is oriented in the circumferential direction. As a result, the reinforcing material is oriented in both the longitudinal direction and the circumferential direction of the tubular body, and a high-strength tubular body reinforced efficiently can be obtained.

[0046]

Next, embodiments of the present invention will be described with reference to the drawings.

Using the apparatus shown in FIGS. 1 and 2, a tubular body having an outer diameter of 50 mm and a thickness of 5 mm was produced by the method of the present invention.

Example 1 A glass fiber chopped strand having a diameter of 23 μm and a length of 6 mm was used as a reinforcing material.
Using a medium-density polyethylene having a melt flow rate of 1.2 g / 10 minutes as measured by JIS-K7210 and using a tumbler to mix the glass fibers in a true specific gravity calculation so that the volume becomes 5% by volume as a raw material.

As shown in FIG. 1, the manufacturing apparatus used in this embodiment includes a 50 mm single screw extruder (11), an extrusion die (12), a water tank (13) as a cooling means, and a take-off machine (14). It is provided with.

As shown in FIG. 2, the extrusion die (12) comprises an outermost jacket die (21), a substantially cylindrical outer die (22), and an outer die.
A substantially cylindrical medium-sized (23) that is driven inside and rotates around a rotation axis that is housed inside (22) and extends in the same direction as the resin extrusion direction.
And an inner die (24) housed inside the middle die (23) and driven to rotate at the same rotation speed as the middle die (23) around the rotation shaft extending in the same direction as the resin extrusion direction. .

An annular flow path (A) is provided between the outer mold (22) and the middle mold (23).
Is formed, an annular flow path (B) between the middle mold (23) and the inner mold (24).
Are formed, and these annular flow paths (A) and (B) are joined at the outlet side portion of the mold (12) to form an annular combined flow path portion.

The illustrated one has a structure in which the outer mold (22), the middle mold (23) and the inner mold (24) are all driven and rotated by drive motors (25), (26) and (27).

The molten mixture containing the reinforcing material and the thermoplastic resin melt-mixed in the extruder (11) is introduced into the extrusion mold (12) through the resin passage (28), and is placed on the circumference of the middle mold (23). An annular flow path between the outer mold (22) and the middle mold (23) through through holes provided at equal intervals
(A) and introduced into the annular flow path (B) between the middle mold (23) and the inner mold (24), and the molten mixture was passed through these flow paths,
The molten mixture that has passed through each of the annular channels in the annular merging channel section of the mold (12) is merged and laminated to form a tubular laminated shape, which is formed into a tubular body (T) from the mold outlet. Extrude. At this time, in the thickness of the tubular body (T), the outer layer (a) becomes a layer in which the reinforcing material is oriented in the annular flow path (A), and the inner layer (b)
Is a layer in which the reinforcing material is oriented in the annular flow path (B).

The production conditions were as follows: an extrusion speed of 0.3 m / min, a melting temperature of the synthetic resin in the single screw extruder of 200 ° C., and a temperature of the mold (12) of 200 ° C. ) And inner mold
(24) was set to 30 rpm, and the outer mold (22) was not rotated.

Example 2 In this example, a wholly aromatic liquid crystal polyester having a liquid crystal transition temperature of 285 ° C. measured according to JIS-K7121 was used as a reinforcing material, and the high-density polyethylene used in Example 1 and the true specific gravity were used. A mixture mixed with a tumbler so that the total aromatic polyester was 5% by volume in the calculation was used as a raw material.

The same manufacturing apparatus as in Example 1 was used.

The manufacturing conditions were the same as in Example 1 except that the melting temperature of the synthetic resin in the single screw extruder (11) was 300 ° C. and the temperature of the mold (12) was 290 ° C. The liquid crystal polymer was subjected to a shearing force due to the rotation of the screw of the single screw extruder (11) and the mold in the mold (12), and had been fiberized in the thermoplastic resin.

Example 3 The same reinforcing material, synthetic resin and manufacturing equipment as in Example 1 were used.

The production conditions for the middle mold (23) and the inner mold (24) are 30 rpm, and the outer mold (22) is 50 rpm in the same direction as the middle mold (23).
It was the same as in Example 1 except that it was rotated in.

Example 4 The same reinforcing material, synthetic resin and manufacturing equipment as in Example 1 were used.

The manufacturing conditions were the same as in Example 1 except that the outer mold (22) and the middle mold (23) were rotated at 40 rpm and the inner mold (24) was not rotated.

Example 5 The same reinforcing material, synthetic resin and manufacturing equipment as in Example 1 were used.

The manufacturing conditions were the same as in Example 1 except that the outer mold (22) and the middle mold (23) were rotated at 30 rpm and the inner mold (24) was rotated at 5 rpm in a different direction from the middle mold (23). I assumed the same.

REFERENCE EXAMPLE 1 For reference, the same reinforcing material and synthetic resin as those used in the above-mentioned Example 1 were used, and a manufacturing apparatus having the structure shown in FIG. 3 set by the present invention and the like was used. Therefore, an apparatus different from that in Example 1 was used.

The extrusion dies used in this embodiment are the outermost jacket dies (31), outer dies (32), middle dies (33), and inner dies.
(34), and the outer mold (32) is driven and rotated by a drive motor (35).

The molten mixture of the reinforcing material and the synthetic resin melt-mixed in the extruder is introduced into an extrusion die through a resin passage (36).
From the holes equally spaced around the circumference of the
The flow was introduced into the flow path (A) composed of 2) and the middle mold (33) and the flow path (B) composed of the middle mold (33) and the inner mold (34). The molten mixture oriented in each flow path was merged and laminated at the most downstream junction of the flow path of the extrusion die to form a tubular body (T). Tubular body
In the thickness of (T), the outer layer (a) is a layer oriented in the channel (A), and the inner layer (b) is a layer oriented in the channel (B).

The production conditions were as follows: extrusion speed 0.3 m /
The melting temperature of the synthetic resin in the single screw extruder was set at 200 ° C., the temperature of the mold was set at 200 ° C., and the outer mold (32) was rotated at 30 rpm.

REFERENCE EXAMPLE 2 The same reinforcing material and synthetic resin as those used in the first embodiment are used. A manufacturing apparatus having the structure shown in FIG. 4 is different from the first embodiment. used.

The extrusion mold used in this reference example is an outer mold (42),
An inner mold (43) and an inner mold (44) are provided, and the inner mold (44) is driven and rotated by a drive motor (45).

The molten mixture of the reinforcing material and the synthetic resin melt-mixed by the extruder is introduced into an extrusion die through a resin passage (46).
From the holes made at regular intervals on the circumference of the middle
The flow was introduced into a flow path (A) composed of 2) and a middle mold (43) and a flow path (B) composed of a middle mold (43) and an inner mold (44). The molten mixture oriented in each flow path was merged and laminated at the most downstream junction of the flow path of the extrusion die to form a tubular body (T). Tubular body
In the thickness of (T), the outer layer (a) is a layer oriented in the channel (A), and the inner layer (b) is a layer oriented in the channel (B).

The production conditions were as follows: an extrusion speed of 0.3 m / min, a melting temperature of synthetic resin in a single screw extruder of 200 ° C., and a mold temperature of 2 ° C.
The temperature was set to 00 ° C., and the inner mold (44) was rotated at 50 rpm.

Evaluation of Tubular Molded Articles The following two tests were performed to evaluate the performance of the tubular molded articles obtained in Examples 1 to 5 and Reference Examples 1 and 2.

<Evaluation of Tensile Strength in Circumferential direction> A ring-shaped sample having a width of 40 m was cut out from each tubular body obtained in the above Examples and Reference Examples, the ring was cut open, and hot pressed at 200 ° C. to obtain a test piece. It was created. This test piece was subjected to a tensile test in accordance with ASTM-D638 to measure the tensile strength in the circumferential direction.

<Evaluation of Tensile Strength in Axial Direction> A sample having a width of 40 mm in the axial direction (extrusion direction) was cut out from each of the tubular bodies obtained in the above Examples and Reference Examples, and hot pressed at 200 ° C. Pieces were made. This test piece is
A tensile test was performed according to ASTM-D638 to measure the tensile strength in the axial direction.

The results obtained are shown in Table 1 below.

[0076]

[Table 1] As is evident from the results of Table 1, according to the examples of the present invention, the obtained tensile strengths in the circumferential direction and the axial direction of the tubular molded product are all very large, and are obtained by the production method of the present invention. The resulting tubular body was efficiently reinforced circumferentially and axially.

On the other hand, the tubular molded body obtained in the reference example had very low tensile strength in both the circumferential direction and the axial direction.

[0078]

According to the method for manufacturing a tubular body according to the first aspect of the present invention, as described above, the substantially cylindrical outer mold and the outer mold are housed inside and extend in the same direction as the resin extrusion direction. A substantially cylindrical middle mold that rotates and rotates around the rotating shaft, and an inner mold that is housed inside the middle mold and rotates around the rotating shaft that extends in the same direction as the resin extrusion direction at the same rotational speed as the middle mold. A mold having an annular flow path is formed between the outer mold and the middle mold, an annular flow path is formed between the middle mold and the inner mold, and these annular flow paths are formed by the mold. And an annular merging flow path portion is formed at the outlet side portion of the mold, and the molten mixture containing the reinforcing material and the thermoplastic resin melt-mixed in the extruder is divided into a plurality of annular flow paths of the mold. The molten mixture is introduced and passed through these flow paths. The molten mixture has passed through the road confluence and then laminated to form a tubular laminate shaping was which is characterized in that the extruded from the die outlet.

According to the third aspect of the present invention, there is provided a method of manufacturing a tubular body, comprising: a substantially cylindrical outer mold that is driven and rotated about a rotation shaft extending in the same direction as the resin extrusion direction; A substantially cylindrical middle mold that is driven inside the mold and rotates at the same rotational speed as the outer mold around the rotation axis extending in the same direction as the resin extrusion direction, and an inner mold housed inside the middle mold A mold having an annular flow path is formed between the outer mold and the middle mold, an annular flow path is formed between the middle mold and the inner mold, and these annular flow paths are formed by the mold. And an annular merging flow path portion is formed at the outlet side portion of the mold, and the molten mixture containing the reinforcing material and the thermoplastic resin melt-mixed in the extruder is divided into a plurality of annular flow paths of the mold. The molten mixture is introduced through these channels, and each The molten mixture that has passed through the Jo flow path joint and laminated to form a tubular laminate shaping was which is characterized in that the extruded from the die outlet.

According to the present invention, in any of the above methods, after the reinforcing material is oriented in the circumferential direction and the axial direction in each flow path, the joining and laminating are performed without disturbing the orientation of the reinforcing material. Thus, a tubular body in which the reinforcing material is efficiently oriented in both the circumferential direction and the axial direction is obtained. Thereby, there is an effect that a tubular body having excellent strength in the circumferential direction, that is, excellent strength in the inside and outside, and excellent strength in the axial direction can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an apparatus for performing the method of the present invention.

FIG. 2 is an enlarged sectional view of an extrusion die portion of the apparatus of FIG.

FIG. 3 is a sectional view of an extrusion die used in Reference Example 1.

FIG. 4 is a sectional view of an extrusion die used in Reference Example 2.

[Explanation of symbols]

 Reference Signs List A annular flow path B annular flow path a layer b layer 11 extruder 12 extrusion die 13 water tank 14 take-off machine 21 jacket type 22 outer mold 23 middle mold 24 inner mold 25-27 drive motor 28 resin passage

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 23:00

Claims (4)

[Claims] 1. A substantially cylindrical outer mold, a substantially cylindrical middle mold housed inside the outer mold and driven and rotated about a rotation shaft extending in the same direction as the resin extrusion direction, and housed inside the middle mold. A mold having a middle mold and an inner mold that is driven and rotated at the same rotation speed in the same direction as that of the middle mold is prepared, and an annular flow is provided between the outer mold and the middle mold. A passage is formed, an annular flow path is formed between the middle mold and the inner mold, and these annular flow paths join at an outlet side portion of the mold to form an annular merge flow path portion. A melt mixture containing a reinforcing material and a thermoplastic resin melt-mixed in the machine,
The molten mixture is introduced into the plurality of annular flow paths of the mold, the molten mixture is passed through these flow paths, and the molten mixture that has passed through each annular flow path at the annular merging flow path section of the mold is merged and laminated. Forming a tubular laminate and extruding it from a mold outlet. 2. The method according to claim 1, wherein the outer mold is driven to rotate around a rotation axis extending in the same direction as the resin extrusion direction and at a rotational speed difference of 1 rpm or more in the same direction as the rotation directions of the middle mold and the inner mold.
The method for manufacturing a tubular body according to claim 1, wherein the tubular body is driven and rotated in a different direction from the middle and inner dies. 3. A substantially cylindrical outer die driven and rotated about a rotary shaft extending in the same direction as the resin extrusion direction, and a rotary shaft housed inside the outer die and extending in the same direction as the resin extrusion direction. Prepare a mold that has a substantially cylindrical middle mold that is driven and rotated at the same direction and rotation speed as the outer mold as the center, and an inner mold that is housed inside the middle mold, and has a ring between the outer mold and the middle mold. A flow path is formed, and an annular flow path is formed between the middle mold and the inner mold, and these annular flow paths are joined at an outlet side portion of the mold to form an annular merged flow path portion, The molten mixture containing the reinforcing material and the thermoplastic resin melt-mixed in the extruder is divided into a plurality of annular flow paths of the mold and introduced, and the molten mixture is passed through these flow paths, and the annular merge of the mold is performed. The molten mixture that has passed through each annular channel in the channel section is merged and laminated to form a tubular laminate. Forming a product and extruding the product from a mold outlet. 4. The method according to claim 1, wherein the inner mold is driven to rotate about a rotation axis extending in the same direction as the resin extrusion direction and in the same direction as the rotation directions of the middle mold and the outer mold at a rotation speed difference of 1 rpm or more.
4. The method for producing a tubular body according to claim 3, wherein the tubular body is driven and rotated in a different direction from the middle mold and the outer mold.