JPH09273668A - Reinforced plastic composite pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily visually recognize wear and flaw of an FRP layer by forming a plurality of colored reinforced plastic layers of different hue, continued in an axial direction of a pipe, laminated so as to make a hue of the layer different from an adjacent layer, in a reinforced plastic layer layered in an inner/outer surface of an intermediate layer formed of mortar. SOLUTION: A composite pipe 1 used in a large bore sewer pipe or the like comprises a pipe-shaped intermediate layer 2 formed by resin mortar and FRP layers 3, 4 layered in an inner/outer surface thereof. Of the inner/outer layer 3, 4, the inner layer 3 is formed by laminating two colored reinforced plastic layers 31, 32 of different hue continued in an axial direction of the pipe. In this composite pipe 1, by wearing, when a first colored layer 31 is sharpened, by making the second colored layer 32 appear in an internal surface of the composite pipe 1, when color of the colored layer coming out to a surface is recognized by periodic inspection or the like, wearing, flawing, etc., can be easily recognized, a trouble of buckling or the like can be previously prevented.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reinforced plastic composite pipe.

[0002]

2. Description of the Related Art In recent years, as an alternative use for large-diameter sewer pipes and small-scale rivers, the inner and outer peripheral surfaces of an intermediate layer made of resin mortar (resin mortar), etc. A reinforced plastic composite pipe having a sandwich structure (hereinafter referred to as "composite pipe" only) in which a reinforced plastic (hereinafter referred to as "FRP") layer made of a curable resin is laminated is used.

Such a composite pipe is lighter in weight and excellent in workability than a metal pipe or a concrete pipe. Further, since the inner and outer surfaces are made of FRP, it has a considerable abrasion resistance.

[0004]

However, when the composite pipe is used as an alternative to a sewer pipe or a small-scale river, fluid such as water flows into the pipe together with earth and sand or a solid substance having high hardness. The FRP layer will be gradually scraped off by earth and sand or solid material with high hardness,
The strength of the tube may be lost and it may buckle.

Therefore, in the conventional composite pipe, when designing the pipeline, the flow rate is calculated, the thickness of the FRP layer is set in advance to the thickness corresponding to the flow rate, and the pipe is replaced after a predetermined period. Or, the FRP layer is reinforced.

However, a large amount of rainfall or the like may cause sediment to flow into the sewer pipe or the like all at once, or solid matter having a high hardness in addition to the sediment. In such a case,
The FRP layer may be worn out at a speed higher than the designed speed, and the strength of the pipe may be lost before the replacement deadline or the repair deadline, causing buckling.

Further, when this composite pipe is used as an exposed pipe, earth and sand and the like collapse from the outside to the outer surface of the pipe, and similarly the FRP layer on the outer surface of the pipe gradually becomes thinner. Therefore, we carry out regular inspections and try to maintain and manage the pipes, but it is very difficult to visually detect such wear and scratches, and it takes a lot of time and effort to perform a complete inspection. There's a problem.

The present invention has been made in consideration of such circumstances.
An object of the present invention is to provide a composite pipe in which wear and scratches on the P layer can be easily visually recognized.

[0009]

In order to achieve such an object, a composite pipe according to the present invention has an FRP made of a reinforcing fiber and a thermosetting resin on the inner and outer peripheral surfaces of an intermediate layer made of resin mortar. In a composite tube in which layers are laminated, at least one of the FRP layers is a tube in which a plurality of colored reinforced plastic layers having different hues continuous in the axial direction of the tube are different in hue from adjacent colored reinforced plastic layers. It is configured to be formed by stacking in the radial direction.

In the above structure, examples of the thermosetting resin include unsaturated polyester resin and epoxy resin. Examples of the reinforcing fiber include glass fiber, synthetic resin fiber, natural fiber carbon fiber, metal fiber and the like, and glass fiber is preferably used.

The shape of the reinforcing fiber is not particularly limited, and for example, a strand shape, a mat shape, or a cross shape is used. As a method for coloring the colored reinforced plastic layer (hereinafter, referred to as “colored layer”), a method of previously mixing a colorant with the resin forming the colored layer, and a method of using pre-colored glass fiber or the like as the reinforcing fiber are used. Etc.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
This will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of a composite pipe according to the present invention. As shown in FIG. 1, in the composite pipe 1, an inner surface FRP layer 3 and an outer surface FRP layer 4 are laminated on the inner and outer surfaces of a tubular intermediate layer 2 made of resin mortar.

The inner FRP layer 3 is composed of two colored reinforced plastic layers 31, 32 which are continuous in the axial direction of the tube and have different hues.
Are laminated. The outer FRP layer 4 is formed of monochromatic FRP.

The composite tube 1 is configured as described above, and when the first colored layer 31 is scraped off due to abrasion, the second colored layer 32 appears on the inner surface of the composite tube 1.
Therefore, if the color of the colored layer on the surface is checked by periodic inspection or the like, wear, scratches and the like can be easily visually confirmed, and items such as buckling can be prevented in advance.

The composite pipe 1 can be manufactured by using the apparatus 5 as shown in FIG. This device 5
The molding apparatus is a drostholm type, and has a rotary shaft 52 extending horizontally from a main body 51 of the apparatus. A base end of a cylindrical mold 53 is connected to the rotary shaft 52 so as to rotate about the rotary shaft 52.

The mold 53 has an open end, the open end is inserted into the curing furnace 6, and an endless steel belt 54 is spirally wound around the outer peripheral surface. The spiral steel belt 54 moves along the surface of the mold 53 toward the open end, which is the tip of the mold 53, as the mold 53 rotates, and reaches the open end of the mold 53. After that,
The mold 53 is returned to the apparatus main body 51 side through the inside of the mold 53, and is wound around the mold 53 again. The outer peripheral surface of the mold 53 constitutes a mold surface 55.

Further, facing the mold surface 55, the apparatus main body 51
A resin supply hose 56 for supplying a thermosetting resin to the side and a resin mortar supplier 57 to the curing furnace 6 side, respectively. That is, the reinforced plastic composite pipe 1 of FIG. 1 is manufactured using this apparatus 5 as follows.

First, the mold 53 is rotated to sequentially move the steel belt 54 wound around the mold 53 to the tip end side of the mold 53, and the mold surface 55 which is the outer peripheral surface of the steel belt 54. The release sheet A is spirally wound on top.
Then, the colored thermosetting resin B is supplied from the resin supply hose 56 onto the release sheet A wound around the mold surface 55, and the glass paper C as a reinforcing material is wound from above the colored thermosetting resin B. The colored layer 1 is formed.

Next, the thermosetting resin B is passed through an impregnation tank E containing the thermosetting resin D colored in a different hue,
The glass strand F impregnated with the thermosetting resin D is wound and laminated from above. Thereafter, the resin mortar G is laminated from the resin mortar feeder 57, and the glass strand H and the glass paper I impregnated with the thermosetting resin are further laminated thereon, and the thermosetting resin is cured in the curing furnace 6. Then, the composite pipe 1 is continuously obtained.

[0020]

The present invention will be described below in more detail with reference to examples. (Example 1) A composite pipe 1 having the same layer structure as in FIG. 1 having a diameter of 800 mm, a first colored layer 31 having a gray color and a thickness of 0.5 mm, and a second colored layer 32 having an orange color. Obtained.

Using a hand grinder, the inner surface of this composite pipe was ground to a diameter of about 100 mm, and the second colored layer 32 with an orange color at the portion having a diameter of about 30 mm from the center was visible and the other portions were visible. However, only the gray color of the first colored layer 31 was visible. Therefore, it was found that a portion having a diameter of about 30 mm from the center was cut off by 0.5 mm or more. Also, when the measured thickness was measured,
It was carved with a maximum thickness of about 0.7 mm.

(Embodiment 2) As shown in FIG. 3, the inner surface FR
Similar to the composite pipe 1 of FIG. 1, except that the P layer 3'is formed of three colored layers, a gray colored layer 31 ', an orange colored layer 32', and a gray colored layer 33 '. A composite pipe 7 was obtained. Glass paper and glass strands were used as the reinforcing fibers in the colored layer 31 ′, glass fiber nonwoven fabric was used as the reinforcing fibers in the colored layer 32 ′, and glass strands were used as the reinforcing fibers in the colored layer 33 ′.

(Embodiment 3) As shown in FIG. 4, the outer surface FR
Like the inner FRP layer 3, the P layer 4 ′ has two colored layers 41.
A composite pipe 8 similar to the composite pipe of FIG. 1 was obtained except that the composite pipe 8 was formed by stacking 'and 42'. The colored layer 41
′ Was formed of a gray thermosetting resin and glass paper, and the colored layer 42 ′ was formed of an orange thermosetting resin and glass strands.

[0024]

EFFECTS OF THE INVENTION Since the composite pipe according to the present invention is constructed as described above, when the inner or outer surface of the FRP layer is worn or scratched, which causes insufficient strength, the surface of the FRP layer is By visually observing the color, it is possible to easily visually and visually find a worn portion or a damaged portion.

Therefore, periodical inspection and the like can be facilitated, repairs can be carried out immediately, and accidents such as buckling can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a composite pipe according to the present invention.

FIG. 2 is an explanatory view of a manufacturing apparatus for manufacturing the composite pipe of FIG.

FIG. 3 is a cross-sectional view of a composite pipe of Example 2.

FIG. 4 is a sectional view of a composite pipe of Example 3.

[Explanation of symbols]

 1 Composite Pipe (Reinforced Plastic Composite Pipe) 2 Middle Layer 3 Inner FRP Layer (Reinforced Plastic Layer) 31 Colored Layer (Colored Reinforced Plastic Layer) 32 Colored Layer (Colored Reinforced Plastic Layer) 3 ′ Inner FRP Layer (Reinforced Plastic Layer) 31 ′ Colored layer (colored reinforced plastic layer) 32 ′ Colored layer (colored reinforced plastic layer) 33 ′ Colored layer (colored reinforced plastic layer) 4 Outer FRP layer (reinforced plastic layer) 4 ′ Outer FRP layer (reinforced plastic layer) 41 ′ Colored layer (colored reinforced plastic layer) 42 'Colored layer (colored reinforced plastic layer) 7 Composite pipe (reinforced plastic composite pipe) 8 Composite pipe (reinforced plastic composite pipe) B Thermosetting resin C Glass paper (reinforced fiber) D Heat Curable resin F Glass strand (reinforcing fiber) G Resin mortar H Glass strand (reinforcing Fiber) I Glass paper (reinforcing fiber)

Claims (1)

[Claims] 1. An inner and outer surface of an intermediate layer made of resin mortar,
In a reinforced plastic composite pipe in which reinforced plastic layers each comprising a reinforcing fiber and a thermosetting resin are laminated, at least one of the reinforced plastic layers is a plurality of colored reinforced plastic layers having different hues continuous in the axial direction of the pipe. Is formed by being laminated in the radial direction of the pipe so that its hue is different from that of the adjacent colored reinforced plastic layer.