JP2003287161A - Fiber reinforced plastic composite tube and its molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce frictional resistance of an inner peripheral surface or an outer peripheral surface of a fiber reinforced plastic composite tube. <P>SOLUTION: Among fiber reinforced resin layers 2 and 3 laminated on the inner-outer peripheral surfaces of a resin mortar layer 1 of the fiber reinforced plastic composite tube P, the fiber reinforced resin layer 2 or 3 of the inner peripheral side or the outer peripheral side is formed of a phenol resin having a property for constituting a low friction surface superior in slidability to reduce the frictional resistance of the tube inner peripheral surface or the outer peripheral surface more than conventional frictional resistance. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforced plastic composite pipe used for construction of a sewer pipe or a propulsion method for tunnel excavation.

[0002]

2. Description of the Related Art As shown in FIG. 1, which is one embodiment of the present invention, a fiber reinforced resin (hereinafter It is often used that a tube wall is formed by laminating layers 2 and 3 made of FRP). Each of these FRP layers 2 and 3 is often formed of an unsaturated polyester resin.

Further, as a method of molding this reinforced plastic composite pipe, as shown in FIG. 2, each layer 1, 2,
Band-shaped layers 4, 5, 6a, 6b as materials for forming 3 are prepared, and the inner layer FRP layer 5, the resin mortar layer 4, and the outer layer FRP layers 6a, 6b are sequentially wound around the outer periphery of the cylindrical core metal 7. Meanwhile, a filament winding molding method in which heat curing is performed in the oven 8 is generally adopted.

This molding method can produce a tube having higher strength than the pultrusion molding. Further, in the manufactured pipe, the inner peripheral side FRP layer 2 is hardened on the outer peripheral surface of the cored bar 7, so that the surface becomes smoother than that of a steel pipe or a concrete pipe.

[0005]

However, when such a reinforced plastic composite pipe is used for a fluid transportation pipe such as a sewer pipe, even if the inner peripheral surface is smooth to some extent, the flow velocity of the fluid flowing inside the pipe is high. Is inevitable due to the frictional resistance of the inner surface of the pipe, which is one of the causes of clogging of the pipe.

Further, in tunnel excavation work, a propulsion method is often adopted, but since the outer peripheral surface of the propulsion pipe used at this time is in contact with the ground, frictional force is generated between the propulsion pipe and the ground. . Particularly, in a tunnel having a bent portion in the middle, the contact between the propulsion pipe and the ground increases at the bent portion, and a larger frictional force is generated. The greater this frictional force, the longer the propulsion line cannot be,
Construction speed will be slower and construction cost will be higher. Therefore, in order to complete the work early and reduce the construction cost, it is required to further reduce the friction resistance of the outer peripheral surface of the reinforced plastic composite pipe used as the propulsion pipe.

Therefore, an object of the present invention is to further reduce the friction resistance of the inner peripheral surface or the outer peripheral surface of the reinforced plastic composite pipe.

[0008]

In order to solve the above problems, according to the present invention, in a reinforced plastic composite pipe having a fiber reinforced resin layer on the inner peripheral side and the outer peripheral side of the pipe wall, the inner peripheral side of the pipe wall is provided. Alternatively, a configuration is adopted in which the fiber-reinforced resin layer on the outer peripheral side or both sides is formed of a phenol resin.

That is, by forming the fiber reinforced resin layer on the inner or outer peripheral side of the pipe wall with a phenol resin having a property of forming a low friction surface having excellent lubricity, the inner or outer peripheral surface of the pipe can be formed. The frictional resistance of was reduced.

Further, according to the method of molding a reinforced plastic composite pipe of the present invention, a reinforced plastic composite pipe in which the fiber reinforced resin layer on the inner peripheral side or the outer peripheral side of the pipe wall is made of phenol resin is used as a material for the pipe wall. It is possible to manufacture a high-strength tube by forming the strip-shaped layer formed by the filament winding molding method in which the strip-shaped layer is heat-cured while being wrapped around the outer periphery of the cylindrical cored bar.

In the molding method, it is preferable to add 5 to 15 wt% of an acid to the phenol resin and cure the resin at a temperature of 100 ° C. or lower.

The above-mentioned molding conditions are set on the basis of the results of experiments under which various tests were carried out to thermally cure the phenol resin. That is, as a result of the experiment, it was found that the addition of 5 wt% or more of various acids such as sulfonic acid to the phenol resin can surely cure the resin in a short time. However, if the addition amount of the acid exceeds 15 wt%, foaming occurs when the resin is cured and the strength after curing may be insufficient, so the addition amount is preferably 15 wt% or less. Also, even when adding an appropriate amount of acid,
If the resin is cured at a temperature higher than 100 ° C., the resin tends to foam, so the heating temperature during molding is preferably 100 ° C. or lower.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows a reinforced plastic composite pipe P according to an embodiment. This reinforced plastic composite pipe P is for a sewer pipe, and as mentioned above, layers 2 and 3 made of fiber reinforced resin (FRP) are laminated on the inner and outer peripheral surfaces of the resin mortar layer 1 to form a pipe wall. ing.

Of the FRP layers 2 and 3, the inner peripheral side FR
The P layer 2 is made of fibers impregnated with a phenol resin, and the outer FRP layer 3 is made of fibers impregnated with an unsaturated polyester resin. Examples of the fibers used include glass fibers, carbon fibers, metal fibers and the like.

FIG. 2 shows a method of molding the reinforced plastic composite pipe P shown in FIG. 1 by a filament winding molding method. In this molding method, first, as a material for forming the respective layers 1, 2, and 3 of the tube wall, a belt-shaped resin mortar layer 4, an inner FRP layer 5 made of fibers impregnated with a phenol resin, and an unsaturated polyester resin are impregnated. The outer layer FRP layers 6a and 6b made of the fibers thus prepared are prepared. Of these, the inner FRP layer 5 contains about 10 w of sulfonic acid.
Add t%. Various acids other than sulfonic acid may be used.

Then, a release sheet 9 such as a polyethylene terephthalate film is wound around the outer periphery of the cylindrical core metal 7, and the FRP layer 5 for the inner layer, the resin mortar layer 4, and the FRP layers 6a, 6b for the outer layer are arranged in this order. A predetermined number of pieces are wound around the inner peripheral side FRP layer 2, the resin mortar layer 1 and the outer peripheral side FRP layer 3 shown in FIG.
The resin in each layer is cured by heating the resin through each layer for a predetermined time.

The outer layer FRP layer 6a is made of fibers impregnated with resin while being fed in the lengthwise direction, and is wound around the core metal 7 at an angle close to the vertical, whereas the outer layer FRP layer 6b is wound. The fibers are sent out in the axial direction of the core metal 7 with their length directions being the same. Therefore, the outer FRP
In the layer 3, the reinforcing fibers of both the FRP layers 6a and 6b cross each other, so that the plastic composite pipe P having high strength can be obtained.

The heating temperature in the oven 8 is set to 100 ° C. or lower in order to prevent foaming during curing of the phenol resin. However, the lower the heating temperature is, the longer it takes to cure the resin. Therefore, the temperature is preferably 50 ° C. or higher from the viewpoint of ensuring good productivity.

The heating time may be set so that the fuel is not wasted for a time longer than the time required for the resin to be sufficiently hardened, and it is often set within a range of 5 to 30 minutes.

That is, this reinforced plastic composite pipe P
Because the inner peripheral FRP layer 2 is formed of a phenol resin having a property of forming a low friction surface having excellent lubricity,
The frictional resistance on the inner surface of the pipe is extremely low. Further, since it is molded by the filament winding molding method, it has sufficient strength as a buried pipe.

Further, in this method for molding a reinforced plastic composite pipe, the phenol resin can be reliably cured in a short time during molding, so that the plastic composite pipe P can be stably and efficiently manufactured.

In the examples shown in FIGS. 1 and 2, the fiber reinforced resin layer on the inner peripheral side is formed of a phenol resin, but as another example of the reinforced plastic composite pipe of the present invention, the fiber on the outer peripheral side is formed. The thing which formed the reinforced resin layer with the phenol resin can be mentioned. The pipe whose outer FRP layer is made of phenolic resin has low frictional resistance on the outer peripheral surface of the pipe,
It is suitable for use as a propulsion pipe in the propulsion method of tunnel excavation work. When manufacturing this pipe, the FRP layer for the inner layer and the FR for the outer layer are prepared by the molding method shown in FIG.
The materials of the P layer may be exchanged with each other and wound.

Further, in the case of a pipe used for reducing the frictional force on both sides of the inner and outer peripheral surfaces, the fiber reinforced resin layers on both inner and outer peripheral sides may be formed of phenol resin.

In order to confirm the friction characteristics and strength of the reinforced plastic composite pipe of the present invention, a friction coefficient measurement experiment by a reciprocal slip tester shown in FIG. 3 and an external pressure test shown in FIG. 4 were conducted.

As shown in FIG. 3, in the reciprocal slip tester, a holder 11 attached to the lower frame 10 holds the test material A obtained by dividing the tube in half, and a ball screw 13 of the upper frame 12 is screwed. By the retainer 14 connected, the counterpart test piece a is held in contact with the inner peripheral surface of the test material A.
Next, the loading plate 15 is attached to the holder 14 of the upper frame 12.
On the test material A and the test piece a on the other side, and the pressing amount of the pressing bolt 17 between the load cell 16 and the retainer 11 mounted on both side walls of the lower frame 10 is set. The load cell 16 is adjusted and a constant load (preload) is applied. Then, in this state, the ball screw 13 is turned to move the opponent sample a, and the moving reaction force F at this time is applied to the load cell 16 of the lower frame 10 by the pressing force N.
The load cell 1 attached to both side walls of the upper frame 12
8, and the friction coefficient μ (= F / N) is calculated.

Using this reciprocal slip tester, a reinforced plastic composite pipe P (Example) shown in FIG. 1 and a conventional plastic composite pipe in which the fiber reinforced resin layers on the inner and outer circumferences were formed of unsaturated polyester resin (Comparative Example) ) Was used as the test material A, and the friction coefficient μ of each inner peripheral surface was calculated. The results are shown in Table 1 together with the results of the external pressure test described later.
Shown in. The friction coefficient in the table is 100 for the friction coefficient of the comparative example.
The friction coefficient of the example is expressed as a ratio with respect to the comparative example.

In the external pressure test, as shown in FIG. 4, the tubular test material B is sandwiched between the flat base 19 and the pressing member 20 via the rubber plate 21, and the pressing member 20 is gradually lowered. The load applied to the test material B is increased substantially evenly in the longitudinal direction, and the stress when the test material B collapses is measured. Table 1 shows the results of measuring the circumferential crush stress of the tubes of the above-mentioned Examples and Comparative Examples.

[0028]

[Table 1]

It can be seen from Table 1 that the pipe of the embodiment has a friction coefficient of the inner peripheral surface which is about half that of the pipe of the comparative example, and the friction resistance is extremely small. Further, it was confirmed that the circumferential crushing stress was equivalent to that of the pipe of the comparative example, and that the pipe had sufficient strength as a buried pipe.

[0030]

As described above, in the reinforced plastic composite pipe of the present invention, since the fiber reinforced resin layer on the inner peripheral side or the outer peripheral side of the pipe wall is formed of the phenol resin, the layer formed of the phenol resin is used. The frictional resistance of the surface of is smaller than before.

Therefore, when applied to a fluid transportation pipe such as a sewer pipe, the fiber reinforced resin layer on the inner peripheral side is formed of a phenol resin to increase the flow velocity of the fluid flowing inside the pipe and prevent the pipe from being clogged. It becomes possible. Also,
Since the phenol resin has excellent heat resistance, it is suitable as a hot water supply pipe connected to a boiler or the like.

Further, when it is applied to a propulsion pipe in a propulsion method for tunnel excavation work, the frictional force with the ground can be reduced by forming the fiber reinforced resin layer on the outer peripheral side with a phenol resin. By making the pipeline longer than before, the construction speed can be increased and the construction cost can be reduced. When the propulsion pipe is used to reduce the frictional force on both sides of the inner and outer peripheral surfaces of the pipe, the fiber-reinforced resin layers on both inner and outer peripheral sides are made of phenolic resin to reduce the frictional force, which causes various problems due to friction. Occurrence can be suppressed.

Further, in the method for molding a reinforced plastic composite pipe of the present invention, the reinforced plastic composite pipe in which the fiber reinforced resin layer on the inner peripheral side or the outer peripheral side of the pipe wall is made of phenol resin is molded by the filament winding molding method. Therefore, it becomes possible to manufacture a high-strength tube.

In the above molding method, by adding 5 to 15 wt% of acid to the phenol resin and curing it at a temperature of 100 ° C. or lower, the phenol resin can be surely cured in a short time during molding, and the reinforced plastic composite The tube can be manufactured stably and efficiently.

[Brief description of drawings]

FIG. 1 is a perspective view of a reinforced plastic composite pipe according to an embodiment.

FIG. 2 is a schematic view illustrating a molding method of the plastic composite pipe of FIG.

FIG. 3A is a schematic view of a reciprocal slip tester, and b is B- of a.
Sectional view along line B

4A and 4B are a front view and a side view, respectively, for explaining a method of an external pressure test.

[Explanation of symbols]

1 Resin mortar layer 2, 3 Fiber reinforced resin layer (FRP layer) 4 Resin mortar layer 5, 6a, 6b FRP layer 7 core 8 oven 9 Release sheet 10 Lower frame 11 cage 12 upper frame 13 Ball screw 14 cage 15 Loading plate 16 load cell 17 Press bolt 18 load cell 19 units 20 Pressing member 21 rubber plate A, B test material a Counterpart sample P reinforced plastic composite pipe

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29K 105: 08 B29L 23:00 B29L 23:00 B29C 67/14 X (72) Inventor Toru Yasumatsu 1 Kitahori, Nishi-ku, Osaka 12-12-19 Kurimoto Iron Works Co., Ltd. (72) Inventor Tomonori Makino 1-12-19 Kitahori, Nishi-ku, Osaka City In-house Kurimoto Iron Works Co., Ltd. (72) Koichi Ito Kita Nishi-ku, Osaka Horie 1-12-19 Kurimoto Iron Works F-term (reference) 3H111 AA01 BA08 BA15 BA34 CA52 CB04 CB14 DA26 DB05 DB16 EA12 EA17 4F100 AE01C AK01C AK33A AK33B AK44 BA03 BA06 BA10A BA10B04A02 DG04A01 EH51A EH51B EH512 EJ082 EJ422 EJ82 GB90 JJ03 JK16 JL02 4F205 AA37 AB03 AD16 AG03 AG08 AH43 HA02 HA23 HA33 HA37 HB02 HC02 HK04 HK05 HL02

Claims (3)

[Claims] 1. A reinforced plastic composite pipe having a fiber reinforced resin layer on an inner peripheral side and an outer peripheral side of a pipe wall, wherein the fiber reinforced resin layer on the inner peripheral side and / or the outer peripheral side of the pipe wall is formed of a phenol resin. A reinforced plastic composite pipe characterized by the above. 2. The reinforced plastic composite pipe according to claim 1, which is formed by a filament winding forming method in which a band-shaped layer which is a material of the pipe wall is heat-cured while being wrapped around the outer periphery of a cylindrical cored bar. Molding method. 3. The phenol resin is added with an acid of 5 to 15 wt.
%, And the composition is cured at a temperature of 100 ° C. or lower.