JPH0367634A - Lining method of pipe line - Google Patents

Abstract

PURPOSE:To form an FRP pipe which is thin and has a high bending modulus, on the inside of a pipe line, by a method wherein a sheet molding compound is developed and pressure-contacted with the inside of the pipe line, both fringes of which is overlapped, heated and cured. CONSTITUTION:A sheet molding compound (SMC) is of a sheetlike molding material where generally a strengthening agent such as a glass fiber is compounded with unsaturated polyester resin along with the other compounding agent, which is made into a sheetlike state by coating with a film, thickened by heating under fixed conditions and made into nonadhesion. The SMC 2 is rolled so that a coating 3 turns outside and pierced through into a pipe line 1. Then the SMC 2 is developed and pressure-contacted with the inside of the pipe line 1. The SMC 2 possesses wider width than an inner circumferential length of the pipe line 1 and both the fringe parts of the SMC 2 are overlapped each other. When the SMC 2 is heated under this condition, along with curing the SMC 2 is stucked to the coating 3, the overlapped parts of the SMC 2 are joined to each other and a rigid FRP pipe is formed.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applicable to pipes mainly buried underground, such as gas pipes, water pipes, sewer pipes, power lines, communication lines, etc. This invention relates to a lining method for forming and reinforcing a strong FRP pipe inside a pipe.

Conventional technology Conventionally, the materials used for lining this type of pipe are woven fabrics, non-woven fabrics, and cylindrical fiber layers made by combining these fabrics in an appropriate structure. , those with an airtight film layer are used. And the said ll in this lining material! ! # Impregnating the layer with a reaction-curing resin liquid, inserting it into the pipe and pressing it against the inner surface of the pipe, heating it to harden the reaction-curing resin liquid, and adhering it to the inner surface of the pipe. A tube made of a reaction-curing resin reinforced with fibers is formed along the inner surface of the tube.

Problems to be Solved by the Invention However, in this type of lining material, woven fabric or non-woven fabric is used as the fiber layer, and this is impregnated with a reaction-curing resin liquid. It is difficult to penetrate the liquid deeply into the gaps between individual fibers, and the effect of reinforcing the fibers is weak.

Therefore, the bending elastic modulus as a fiber-reinforced resin pipe is small, and the resistance to external forces is insufficient. Therefore, for example, if groundwater enters through a crack in the pipe and external water pressure is applied to the fiber-reinforced resin pipe, 1aI! The miscellaneous reinforced resin pipe cannot withstand the water pressure and may collapse due to the water pressure, narrowing the internal fluid flow path.

It is possible to increase the bending rigidity of the fiber-reinforced resin pipe by making the thickness of the fiber layer in the lining material sufficiently large. However, the lining material itself becomes thick and difficult to handle, and it is even more difficult to deeply penetrate the thick fiber layer with a large amount of the reaction-curing resin liquid. Moreover, since the thickness of the fiber-reinforced resin pipe becomes large, the effective inner diameter of the pipe line becomes small and the flow path becomes narrow, which is not preferable.

The present invention has been made in view of the above circumstances, and the pipe line is lined with FRP highly reinforced with high-rigidity fibers such as glass fiber, and the inner surface of the pipe line is made of thin FRP pipe with a high bending elastic modulus. The purpose is to provide a method for forming.

As a means of solving the problem, the present invention provides a method of rolling a sheet molding compound having a width exceeding at least the inner circumference of the pipe so that the width thereof is smaller than the inner diameter of the pipe, and inserting the sheet molding compound into the pipe. , the sheet molding compound is spread and pressed against the inner surface of the pipe, the open edges of the sheet molding compound are overlapped, and then the sheet molding compound is heated and hardened.

In this method, an airtight coating is applied to one side of the sheet molding compound, and the sheet morph molding compound is rolled with the coating on the outside and inserted into the conduit.

Further, in the above method, an airtight film is attached to one side of the sheet molding compound, and the side edge of the film is wrapped around the side edge of the sheet molding compound and folded back between the opposite sides, and the sheet molding compound is It is also possible to wrap the tube so that the membrane is on the inside and insert it into the pipe.

Furthermore, in these methods, the width of the sheet molding compound shall be 72 times or more the inner circumference length of the pipe, and the sheet molding compound shall overlap on the inner surface of the pipe within a range of - circumference or more. It is also possible to do this.

Furthermore, in the method of the present invention, a flexible cylindrical expansion member is inserted inside the sheet molding compound wound to a diameter smaller than the inner diameter of the conduit, and a pressure fluid is fed into the expansion member to form a sheet molding compound. It is preferred to spread the molding compound, in which case the spreader member may be removed after spreading the sheet molding compound, or the spreader member may be bonded integrally to the inner surface of the sheet molding compound after spreading the sheet molding compound. You can also.

In another method of the present invention, a strip-shaped sheet molding compound is spirally wound around the outer periphery of a flexible cylindrical expansion member having a diameter approximately equal to the inner diameter of the conduit so that the edges thereof overlap. , insert this into the pipe, feed pressure driftwood into the expanding member to expand it, press the sheet molding compound against the inner surface of the pipe, and heat and harden the sheet molding compound. It is characterized by encouraging people.

The sheet molding compound (hereinafter abbreviated as "SMC") referred to in the present invention is generally made by blending an unsaturated polyester resin with a reinforcing agent such as glass fiber along with other compounding agents, and forming it into a sheet by covering both sides with a film. This is a sheet-shaped molding material that is heated under predetermined conditions to thicken it and make it non-adhesive.

The raw materials for SMC generally include unsaturated polyesters, crosslinkers, thickeners, reinforcing agents and other compounding agents. The unsaturated polyester is obtained by reacting an unsaturated dibasic acid, a saturated dibasic acid, and a glycol by a conventional method, and examples of the unsaturated dibasic acid include maleic acid, fumaric acid, etc. is used, and fumaric anhydride, isophthalic acid, etc. are used as the saturated dibasic acid. Further, examples of ρj of glycols include ethylene glycol, propylene glycol, and the like.

As the crosslinking agent, styrene, diallyl phthalate, etc. are used, and based on 100 parts by weight of unsaturated polynisdel,
It is blended in a proportion of 20 to 60 parts by weight.

As the thickener, alkaline earth metal oxides or hydroxides are usually used, such as magnesium oxide, magnesium hydroxide, and the like. And its blending amount is
It is blended in an amount of 0.3 to 3 parts by weight based on a total of 100 parts by weight of the unsaturated polyester and the crosslinking agent.

As reinforcement, chopped strands of E-glass rovings are generally used. The roving preferably has a filament diameter of 9 to 15 μm and a convergence number of 100 to 400 filaments. There is also chopped strands.

Further, by using S glass instead of E glass, the strength and elastic modulus are improved, and by using glass fiber containing zirconium oxide, alkali resistance is improved. Furthermore, weight reduction can be achieved by using carbon fiber instead of glass fiber.

These tougheners are rated at 10-7 for the entire SMC raw material.
It is appropriate to mix it in a proportion that accounts for 0% by weight.

Other compounding agents include low shrinkage agents, mold release agents, fillers,
A hardening agent and the like are added.

The low shrinkage agent suppresses volumetric shrinkage during curing, and polyvinyl acetate, polystyrene, and the like are used.

As the mold release agent, zinc stearate, calcium stearate, etc. are used.

The filler has the function of suppressing separation of the SMC components and making the components flow uniformly during molding, and heavy calcium carbonate, aluminum hydroxide, etc. are used.

The curing agent acts as a catalyst to promote the reaction between the unsaturated polyester and the crosslinking agent, and benzoyl peroxide, t-butyl peroxide, and the like are used.

In addition, if it is necessary to further improve physical properties such as mechanical properties and durability, it is also possible to use vinyl ester resin or epoxy resin instead of unsaturated polyester and SMC using an isocyanate compound as a thickener. can.

To manufacture SMC, the above raw materials are put into a kneader and thoroughly kneaded, and chopped strands obtained by cutting glass roving with a cutter are impregnated with the raw materials. This is then sandwiched between polyester or other films.
The sheet-like material is heated at a predetermined temperature and time to thicken it and make it non-stick.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the state in which the pipe line is lined according to the present invention. 1 is a conduit, and 2 is an SMC lined on the inner surface of the conduit 1. This SMC 2 has a width N larger than the inner peripheral length of the pipe line 1, and has an airtight film 3 attached to one side thereof. And that SMC
2 is rolled up so that the skin 1113 is on the outside, and pushed through the pipe 1.

Then, the SMC 2 is expanded and pressed against the inner surface of the conduit 1. At this time, since the SMC 2 has a width larger than the inner peripheral length of the conduit 1, both edges of the SMC 2 overlap. When 3MC2 is heated in this state, SMC''2 hardens and adheres to the three cores of the coating, and in the overlapped area, the ohno-wrapped SMC2 joins.
Forms a rigid FRP pipe.

Note that the skin wA3 can be used as it is without peeling off the film attached between both sides of the skin wA3 from the SMC surface when manufacturing the SMC.

Further, in this embodiment, the SMC 2 can be wound as it is and inserted into the conduit 1 without attaching the membrane 3 to the SMC 2. According to this method, the SMC2 can be bonded directly to the inner surface of the pipe line 1, and the strength of the lining is high.However, on the other hand, if there are air bubbles in the SMC2, There is a risk that groundwater, etc. that has entered through the damaged part of the pipe can penetrate into the interior through the bubbles, so there are advantages and disadvantages.

FIG. 2 shows another embodiment of the invention.

In this embodiment, a coating 3 is attached to one side of the SMC 2 as in the previous embodiment, and the coating Jl! The side edge of SMC 3 is wrapped around the side edge of SMC 2 and folded back to the opposite side. Then, the SMC 2 is wound so that the skin WA3 is on the inside, and as in the optical embodiment, it is inserted into the conduit 1, expanded, and pressed against the inner surface of the conduit 1, and the SMC 2 is heated and hardened.

FIG. 3: Still another embodiment is shown.

SMC2 has a width that is twice as wide as the inner circumference of conduit 1, and when it is expanded, SMC2 overlaps the inner circumference of conduit 1 over the sea circumference. ing.

FIG. 4 shows a method of expanding the SMC 2 in the embodiment of FIG. 1. Reference numeral 4 denotes a flexible expansion member having a cylindrical airtight property, and is inserted into the inside of the wound SMC 2. By inserting a pressure fluid such as compressed air into the expanding member 4, the expanding member 4 is expanded, and the SMC 2 is expanded by the expanding member 4 and brought into pressure contact with the inner surface of the conduit 1.

The expansion member 4 may be a rubber tube or a cylindrical woven fabric with a PIA layer formed on the inner surface thereof.

Further, the expanding member 4 can be removed from the inside of the SMC 2 after the SMC 2 is expanded and brought into pressure contact with the pipe line, or after the SMC 2 is hardened. Also, without removing it,
At the same time as SMC2 is cured, it is bonded to SMC2, and SM
It can also be lined integrally with C2.

FIG. 5 shows a further embodiment of the present invention, and shows the state before the SMC 2 is inserted into the conduit 1. In this example, tube i? SMC 2 cut into strips is spirally wound around the outer periphery of a cylindrical expansion member 4 having a diameter 7 equal to the inner diameter of 81 so that the edges thereof overlap. Then, this is folded and inserted into the pipe line 1, and a pressure fluid is inserted into the expansion member 4 to inflate it, so that the SMC 2 is pressed against the inner surface of the pipe line 1 and hardened by heating.

Function In the present invention, the SMC 2 is wound and inserted into the conduit 1,
This is expanded and pressed against the inner surface of the pipe line 1, but the SM
Since C2 does not have adhesive properties, the parts that come into contact with each other in the rolled state do not stick or become difficult to unfold, and can be appropriately unfolded. Then expand and pipe 1
When heated while being pressed against the inner surface, the SMC 2 hardens and forms a rigid FRP pipe along the inner surface of the conduit 1. At this time, the overlapping portions of both side edges of the SMC2 are bonded together with the hardener 1 and are integrated, forming an integral tube with a wide joint.

In the FRP pipe molded by SMC2, chopped glass fiber strands are uniformly mixed in unsaturated polyester resin, and the unsaturated polyester resin is evenly impregnated into the chopped strands. Therefore, it becomes rigid and has an extremely high bending modulus.

Effects of the invention Therefore, according to the invention, the tube 11! A rigid FRP pipe with a high bending elastic modulus is formed on the inner surface of 1.
Pipe line 1 is firmly connected. That is, the FRP pipe has a high resistance to external force, and even if groundwater intrudes from a damaged part of the pipe 1, it can withstand the external water pressure and will not collapse.

According to the invention of claim 1, a lining with a thickness of 2.2 nl was applied to a conduit having a diameter of 300 mIn, and when the lining was extracted from the conduit and the characteristics of the lining were examined, it was found that the flexural modulus of elasticity was 6.
8.700 to 9. &, The external water pressure resistance was 9 right at 0°53.

On the other hand, as a conventional lining material, long crow fiber threads are woven into the outer surface of a tubular woven fabric to form a 4.211 mm thick fiber layer, and a flexible film layer is formed on the inner surface of the fiber layer. The fiber layer of the lining material was impregnated with epoxy resin and lined on the inner surface of the pipe. Then, the lining was peeled off from the pipe and its properties were examined.The bending elastic modulus was 38.0OOki, and the resistance to external water pressure was 0.0.
It was 30kg.

Although the thickness of the lining material of the present invention is about half that of the conventional lining material, the flexural modulus is significantly higher, and therefore, the lining material is also extremely resistant to external water pressure.

Moreover, according to the present invention, since the bending elastic modulus is large, the thickness of the lining can be reduced, the extent to which the flow path of the pipe becomes narrow is small, and a sufficient flow rate can be ensured.

[Brief explanation of drawings]

FIGS. 1-4 are cross-sectional views of conduits lined according to embodiments of the present invention. FIG. 5 is an exploded perspective view of an SMC used in another embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. A sheet molding compound (2) having a width exceeding at least the inner peripheral length of the conduit (1) is applied to the conduit (1).
This sheet molding compound (2) is rolled up so that it has a smaller diameter than the inner diameter of (1) and inserted into the pipe (1).
is developed and brought into pressure contact with the inner surface of the conduit (1), and the both side edges of the sheet molding compound (2) are overlapped, and then the sheet molding compound (2) is heated and hardened. Method 2 for lining pipes In the method according to claim 1, an airtight film (3) is attached to one side of the sheet molding compound (2), and the sheet molding compound (2) is lined with an airtight film (3).
A method according to claim 1, characterized in that the sheet molding compound (2) is coated with an airtight coating (3) on one side of the sheet molding compound (2). ), and at the same time wrap the side edge of the film (3) around the side edge of the sheet molding compound (2) and fold it back to the opposite side.
4. A method according to claim 1, 2 or 3, characterized in that the width of the sheet molding compound (2) is the same as that of the pipe. Road (1)
5. A method for lining a pipe line (5), characterized in that the inner diameter of the pipe line (1) is approximately twice or more the inner diameter of the pipe line (1). A flexible cylindrical expansion member (4) is inserted into the inside of the expanded sheet molding compound (2), and pressurized fluid is fed into the expansion member (4) to expand the sheet molding compound (2). Method 6 for lining a conduit, characterized in that the expansion member (4) is expanded and then the expansion member (4) is withdrawn. Method 7 for lining a conduit, characterized in that after expanding the sheet molding compound (2) by using a method, the expanding member (4) is integrally bonded to the inner surface of the sheet molding compound (2).Inner diameter of the conduit (1) A band-shaped sheet molding compound (2) is spirally wound around the outer periphery of a flexible cylindrical expansion member (4) with a diameter approximately equal to that of the conduit ( 1) and expands the expansion member (4) by feeding pressure fluid into the expansion member (4) to spread the sheet molding compound (2) into the conduit (1).
) The sheet molding compound (2) is pressed against the inner surface, and the sheet molding compound (2) is heated and cured.
Method of lining pipes