JPH0333096B2 - - Google Patents

Abstract

PURPOSE:To reinforce a connecting part easily and accurately, by a method wherein a space between mutual thermoplastic resin layers of an FRP coupler and FRP tube are stuck with an adhesive agent, an FRP layer is made to expose, a photosensitive sheet is wound and thermosetting resin is made to cure by light. CONSTITUTION:An FRP tube A is constituted by providing an FRP layer 2 on the outside of a core material 1 of a vinyl chloride tube and providing a vinyl chloride resin coating layer 3 on the outside of the FRP layer 2. The coating layer 3 of a tube end of the FRP tube A is scraped by about 80mm and the FRP layer 2 is scraped by 40mm. On the other hand, an FRP coupler B obtained by providing an FRP layer 5 on the outside of a socket 4 made of vinyl chloride is constituted. Both the FRP tube A and FRP coupler B are connected with the each other by making the FRP tube A insert into the FRP coupler B by applying an adhesive agent for the vinyl chloride to the outside of the core material 1 of the tube end of the FRP tuve A and an inner insertion opening of the FRP coupler B. About 20mm from an end face of the outside FRP layer 5 of the FRP coupler B and the outside of the FRP layer 2 of the FRP tube A are scrubbed well sand paper and so dusts and oily ingredient are eliminated with acetone. A photosensitive sheet D is wound round the outside of a connecting part C between the FRP tube A and FRP coupler B approximately two times and reinforcement is achieved by making the photosensitive sheet D cure under existence of sunlight.

Description

Detailed Description of the Invention The present invention relates to reinforcement of FRP pipe connections used in the field of piping using FRP pipes such as the field of plant piping for transporting acid/alkaline solutions, the field of hot springs transporting high-temperature water, or the field of thermal power generation. Regarding the method.

(Prior art) Conventionally, when connecting FRP pipes to each other through a joint, as shown in Fig. 3, after connecting FRP pipes b and b by inserting them into FRP joint a, the diameter of joint a and pipe b are If there is a large step between the diameters of , apply a two-component reaction-curing putty to step c and fill in step c with putty to increase the strength of the connection and prevent pipe b from coming out from the connection. In order to do this, glass fiber is wound around the outside of the connection, and then a thermosetting resin that has been mixed and stirred with a catalyst added in advance is applied and impregnated to form an FRP hand wrap layer d, which is then hardened to reinforce the connection. are doing.

(Problems with the Prior Art) However, the above-described method of connecting FRP pipes has various drawbacks as listed below.

(1) Glass fiber is wound around the outside of the connection part, and a thermosetting resin is applied over it and hardened to reinforce it, so it has poor construction properties.

(2) If there is a large step between the diameter of the FRP pipe and the FRP fitting, apply putty to eliminate the step.
Since the putty is a two-component reaction-curing type, it takes time to mix the base ingredient and hardener, and the curing time remains constant unless the mixing ratio of the base ingredient and hardener is changed due to external pressure. I can't.

(Means for Solving the Problems) The present invention was made to solve the problems of the prior art, and its purpose is to simplify the reinforcing work of the connection between the FRP pipe and the joint. The purpose of the present invention is to provide a method for reinforcing FRP pipe joints that can reduce the stress and fully exhibit the reinforcing effect.
After connecting FRP pipes through FRP fittings,
After polishing the FRP layer of the pipe and the FRP layer of the FRP joint with sandpaper and wiping it with a solvent,
Apply photosensitive putty directly to the connection between the FRP pipe and FRP fitting, or if there is a step in the connection, apply photosensitive putty to the step, then wrap a photosensitive sheet over it and cure it with light to connect the FRP pipe. We adopted a method of reinforcing the connection part of the FRP joint from the outside.

The photosensitive sheet used in the present invention is one that is cured by light, and 0.001 part or more of a photosensitizer is added to 100 parts of a thermosetting resin such as an unsaturated epoxy ester resin or an unsaturated polyester resin. Then, a resin mixture based on a thermosetting resin (unsaturated epoxy ester resin, unsaturated polyester resin) that has been chemically thickened by adding a thickener is impregnated into mat-like glass fibers and defoamed. At the same time, both sides of the sheet are covered with polyethylene film, etc., and rolled up. When used, the sheet is cut to an appropriate width. In addition, photosensitive putty is something that hardens with light, and contains 0.001 part or more of a photosensitizer per 100 parts of a thermosetting resin, such as an unsaturated epoxy ester resin or an unsaturated polyester resin, and further increases the viscosity. It is made into a putty by adding an agent and chemically thickening it. In addition, when chemical resistance is required, a material to which glass flakes are further added is used.

(Function) Therefore, when applying the reinforcing method of the present invention to reinforce the connection between an FRP pipe and an FRP joint, first,
After connecting the FRP pipes via FRP fittings,
After polishing the FRP layer of the FRP pipe and the FRP layer of the FRP joint with sandpaper and wiping it with a solvent,
Apply photosensitive putty directly to the connection between the FRP pipe and FRP fitting, or if there is a step in the connection, apply photosensitive putty to the step and then wrap a photosensitive sheet over it and cure it with light. This is to reinforce the connection part of FRP joints from the outside.

Since the present invention uses a photosensitive sheet and a photosensitive putty, it is possible to mix the base resin and hardening agent as in the past, or change the mixing ratio of the base resin and hardener depending on the outside temperature. No work is required, and the sheet can be applied simply by pressing it onto the putty or into complex piping areas. In addition, since the photosensitive sheet is in a semi-gelled state, unlike working with liquid thermosetting resin, it can be worked in a dry environment, preventing resin scattering and
There is no sag at all, and even when reinforcing piping in high places, work can be done safely in a completely hygienic work environment.

(Example) Hereinafter, an example of the reinforcing method for an FRP pipe joint of the present invention will be described.

Example 1 A PVC pipe with a diameter of 25 mm is used as the core material 1, and an FRP layer 2 with a thickness of 0.6 mm is provided on the outside of this core material 1.
An FRP pipe A is constructed by providing a coating layer 3 of vinyl chloride resin with a thickness of 0.8 mm on the outside of the FRP layer 2. Then, the coating layer 3 at the end of this FRP pipe A is approximately 80 mm,
Remove about 40mm of FRP layer 2 using an electric plane. On the other hand, PVC socket 4 with a diameter of 25 mm
An FRP joint B is constructed in which an FRP layer 5 with a thickness of 2 mm is provided on the outside of the FRP joint B.

Next, the outside of the core material 1 at the pipe end of the above FRP pipe A and
Apply vinyl chloride adhesive to the inside insertion port surface of FRP joint B, insert FRP pipe A into FRP joint B, and connect the two. The first one shows the state after connection.
In this figure, the connecting portion C between the FRP pipe A and the FRP joint B is further reinforced from the outside. This reinforcing method is the main part of the present invention, and first, the FRP joint B shown in Fig.
Rub the outer FRP layer 5 thoroughly with sandpaper approximately 20 mm from the end surface. At the same time, FRP pipe A
Rub the outside of FRP layer 2 well with sandpaper,
Wipe both sides with acetone to remove dust and oil components.

Next, wrap photosensitive sheet D (indicated by imaginary lines) cut to a width of 50 mm twice around the outside of the connection C between FRP pipe A and FRP joint B, and then wrap it around the outside surface of pipe A and joint B.
The photosensitive sheet D is pressed tightly against the outer surface of the sheet and left under sunlight for 15 minutes to harden the photosensitive sheet D and complete the reinforcement.

The thickness of the photosensitive sheet layer at this time was 0.8 mm.

Example 2 A PVC pipe with a diameter of 75 mm is used as the core material 1, and an FRP layer 2 with a thickness of 1.2 mm is provided on the outside of this core material 1.
An FRP pipe A is constructed by providing a coating layer 3 of vinyl chloride resin with a thickness of 0.8 mm on the outside of the FRP layer 2. Using an electric plane, remove about 160 mm of the coating layer 3 and 80 mm of the FRP layer 2 from the end of the FRP pipe A. On the other hand, on the outside of the 75mm diameter PVC socket 4,
An FRP joint B is constructed by providing an FRP layer 5 with a thickness of mm.

Next, the outside of the core material 1 at the pipe end of the above FRP pipe A and
Apply vinyl chloride adhesive to the inside insertion port surface of FRP joint B, and insert FRP pipe A into FRP joint B to connect the two. The second one shows the state after connection.
In this figure, the connecting portion C between the FRP pipe A and the FRP joint B is further reinforced from the outside. This reinforcing method is the main part of the present invention, and first, the FRP joint B shown in Fig.
Rub the outer FRP layer 5 approximately 60 mm from the end surface thoroughly with sandpaper. At the same time, FRP layer 2 of FRP pipe A
Rub the outside well with sandpaper and wipe both sides with acetone to remove dust and oil components and create microscopic irregularities on the surface.

Next, apply photosensitive putty 7 to the step 6 between the FRP pipe A and the FRP joint B to eliminate the step, and then cut the photosensitive sheet D to a width of 100 mm as shown by the imaginary line.
is wrapped around the putty 7 of the stepped portion 6 and brought into close contact with the putty 7, and is cured by heating and irradiating it with an ultraviolet lamp for about 25 minutes.A coating is further applied onto the photosensitive sheet D to complete the reinforcement of the bonded portion C. At this time, the thickness of the photosensitive sheet layer was 1.1 mm.

(Effects) As explained above, according to the method of the present invention,
After bonding the thermoplastic resin layers of the FRP joint and FRP pipe with a normal heat-resistant adhesive,
Peel off the coating layer of the FRP pipe to expose the FRP layer,
Apply heat treatment with sandpaper along with the FRP layer of the FRP joint, then wipe the surface with a solvent, apply photosensitive putty directly to the connection part, or if there is a step in the connection part, apply photosensitive putty on top of it. The sheet is wrapped around the sheet and the thermosetting resin in the photosensitive sheet is cured by light to strengthen the joint between the FRP pipe and the FRP joint.

Therefore, the connection between FRP pipes and FRP joints can be reinforced very easily and reliably in the field of plant piping that transports acid/alkaline solutions, hot spring fields that transport high-temperature water, or piping using FRP pipes in thermal power generation fields, etc. can do.

In addition, if you expose the photosensitive sheet to light after winding it, the photosensitive sheet will harden in a short time of 15 to 30 minutes, making it possible to strongly connect the FRP pipe and the reinforcing joint together. Practical value can also be improved, such as making it possible to pass water into the pipe within a short time.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views showing the connection between an FRP pipe and an FRP joint reinforced using the reinforcing method of the present invention, and Figure 3 is a cross-sectional view showing the connection between an FRP pipe and an FRP joint using a conventional method. It is. A: FRP pipe, B: FRP joint, C: connection part,
D: Photosensitive sheet, 1: Core material, 2: FRP layer,
3: Covering layer, 4: Socket, 5: FRP layer, 6:
Step part, 7: Photosensitive putty.

Claims (1)

[Claims] 1 After connecting the FRP pipes via FRP joints,
After polishing the FRP layer of the FRP pipe and the FRP layer of the FRP joint with sandpaper and wiping it with a solvent,
Apply photosensitive putty directly to the connection between the FRP pipe and FRP fitting, or if there is a step in the connection, apply photosensitive putty to the step, then wrap a photosensitive sheet over it and cure it with light to connect the FRP pipe. A method for reinforcing FRP pipe joints, which is characterized by reinforcing the joints of FRP joints from the outside.