JPH0314621B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for connecting FRP composite pipes that is applied in the piping field of FRP composite pipes.

(Prior art and its problems) Conventionally, when connecting FRP composite pipes through a joint, the FRP composite pipe and the joint were connected by screw fitting, or the FRP composite pipe and the joint were connected using an adhesive. It was connected using adhesive.

However, the conventional method of connecting the FRP composite pipe and the joint described above has the following problems.

When the FRP composite pipe and the fitting are connected by threaded fitting, there is a risk that the solution inside the pipe will ooze out from the threaded part. This phenomenon becomes especially noticeable when the solution inside the tube is a high temperature solution of around 100℃.
This is extremely dangerous when it comes to transport pipes for acid/alkaline solutions, etc.

When the FRP composite pipe and the fitting are connected with adhesive, if the solution inside the pipe becomes around 100℃,
The adhesive strength of the adhesive decreases, and if the solution in the tube is an acid/alkaline solution, the adhesive deteriorates due to the acid/alkaline solution, making it impossible to maintain adhesive strength for a long time.

In the case of FRP composite tubes, it is extremely dangerous because the solution inside the tube oozes out of the tube through the glass fibers on the end surface of the tube through the tube phenomenon. For this reason, the outer surface of the joint between the FRP composite pipe and the joint is reinforced with a reinforced plastic layer, but the glass fiber is wrapped around the joint and a thermosetting resin is applied over it, impregnated, and hardened. , the work is time-consuming and the appearance is poor, making it impractical.

(Means for Solving the Problems) The present invention has been made in order to solve the conventional problems, and its purpose is to
FRP composite pipes and fittings can be easily connected, and the solution inside the pipes will not ooze out from the joints.
Furthermore, the connection part can be sufficiently reinforced.
Our goal is to provide a connection method for FRP composite pipes.
As a technical means to achieve this objective, in the present invention, the reinforced plastic layer at the end of the FRP composite pipe is scraped off to a required length to expose the inner core layer made of thermoplastic resin, and then the reinforced plastic layer at the end of the FRP composite pipe is scraped off to expose the inner core layer made of thermoplastic resin. Apply adhesive to the inner surface of the socket of the FRP joint formed with a reinforced plastic layer on the outside and the outer surface of the inner core layer, insert the inner core layer into the socket of the FRP joint, connect the two, and then After wiping the outer surface of the joint between the FRP composite pipe and the FRP joint with a solvent, we applied a primer made by dissolving a resin whose main component is vinyl chloride monovinyl acetate copolymer in a solvent, and then dried it.
A flexible reinforcing sheet made by impregnating glass fibers with a photocurable resin whose main component is unsaturated epoxy ester resin was then wrapped around the glass fibers, which was then irradiated with light to cure and connect. be.

(Function) Therefore, the reinforced plastic layer of the FRP composite pipe is scraped off to expose the thermoplastic resin inner core layer.
Since the inner core layer and the thermoplastic resin socket constituting the inside of the FRP joint are bonded, the bond can be easily and strongly bonded. Furthermore, even if a high temperature solution such as an acid or alkali is poured into the tube, the inner surface of the tube will not deteriorate because it is made of a corrosion-resistant thermoplastic resin (vinyl chloride resin, etc.). Furthermore, since the connection between the FRP composite pipe and the FRP joint is reinforced by wrapping a photocurable reinforcing sheet, there is no need for reinforcement, and the reinforcement can be made uniform, so the connection can be easily reinforced. It can exhibit various practical advantages such as not coming off.

(Embodiments) Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

In the example, the inner core layer 1a is a vinyl chloride pipe, and the reinforced plastic layer 1b made of unsaturated polyester resin and glass fiber is fixed to the outside of the pipe, and the reinforced plastic layer 1b made of thermoplastic resin is fixed to the outside of the reinforced plastic layer 1b. An FRP socket joint 2 is made of a three-layer FRP composite pipe 1, which is covered with a coating layer 1c, and a reinforcing plastic layer 2b made of unsaturated polyester resin and glass fiber is coated on the outside of a vinyl chloride resin socket joint 2a. The case where the connection is made via is explained as an example.

First, the first step is to scrape off the reinforced plastic layer 1b at the pipe end connection part of the FRP composite pipe 1 to expose the inner core layer 1a.First, check the socket dimensions of the mating FRP socket joint 2, and Hold a knife at a position approximately twice the length of the mouth.
A deep cut 3 is made in the circumferential direction of the coating layer 1c of the FRP composite pipe 1, and a part of the coating layer 1c is forcibly peeled off (see FIG. 1). Next, using plane A, scrape off the reinforcing plastic layer 1b at the end of the FRP composite pipe from above the inner core layer 1a to a length slightly longer than the length of the socket of the joint 2.

Incidentally, the plane A used in the method of the present invention has a diamond blade 5 rotatably supported electrically on the main bottom plate 4, and a cutting allowance for the reinforced plastic layer 1b of the FRP composite pipe 1 is provided on the back side of the diamond blade 5. Attach a stopper 6 to accurately release the material, adjust this stopper 6, and place the end surface of the FRP composite pipe 1 against this stopper 6 to form the reinforced plastic layer 1b so that it can be scraped off to a predetermined length. ing. In addition, in front of the diamond blade 5 of this planer A, presser plates 7, 7 are attached to adjust the pipe wall portion of the FRP composite pipe 1 to a predetermined thickness. The presser plates 7, 7 are attached to the front part of the bottom surface of the planer A in the same plane in the right and left direction perpendicular to the axis of the diamond blade 5, and the tip parts 7a, 7b are respectively cut out diagonally. It is formed so as to grip the FRP composite pipe 1 diagonally from above. Further, the holding plates 7a, 7a are attached so as to be slidable left and right, and are attached with bolts 8, 8.
However, it can be held in place by holding it in place.

Therefore, even with this plane A, FRP composite pipe 1
When scraping off the reinforced plastic layer 1b, first place the end of the tube against the stopper 6 of the planer A, and adjust the amount of scraping at the end of the tube while sliding the stopper 6 back and forth. After fixing the stopper 6, apply the presser plate 7, 7 to the outside of the FRP composite pipe 1, and check the contact with the diamond blade 5.
Fix the presser plates 7a, 7a. In this way
After adjusting the position of FRP composite pipe 1 and plane A,
The diamond blade 5 is rotated to begin scraping off the reinforced plastic layer 1b.

In addition, when the entire FRP composite pipe 1 or the inner core layer 1a is oval, if the pipe wall is scraped with the planer A, the reinforcing plastic layer 1b may remain in a part of the pipe. Therefore, the thickness of the inner core layer 1a is made 0.2 to 0.5 mm thicker than the standard for water pipes, so that even if the inner core layer 1a is cut too much with a plane A, it will fit tightly into the joint.
It is formed to maintain sufficient adhesive strength.

In addition, a handle 10 is provided at the front of the main body 9 of the plane A.
is provided, and the shaft rod 11 of this handle 10 is fitted with a plane A.
By moving the bottom plate 4 up and down and moving one of the presser plates 7, 7 in the vertical direction, the position of the cutting edge of the diamond 5 of the plane A and the FRP composite pipe 1 is adjusted, and the reinforced plastic layer is connected to the bottom plate 4 of the It is formed so that a part of 1b can be completely removed. After adjusting the position of the plane A with the diamond blade 5, the diamond blade 5 is rotated and at the same time, the FRP composite pipe 1 is slowly rotated to completely scrape off a part of the reinforced plastic layer 1b.

Next, move on to the second step.

The second step is to insert the exposed inner core layer 1a of the FRP composite pipe 1 into the socket of the FRP joint 2 and connect the two with adhesive. The outer peripheral surface of the inner core layer 1a of the tube 1 is sufficiently rubbed with sandpaper to remove the reinforcing plastic remaining on the inner core layer 1a. next,
Apply adhesive to the socket part 2c made of vinyl chloride of the FRP joint 2, apply adhesive to the outer periphery of the inner core layer 1a at the same time, and insert the inner core layer 1a into the socket part 2c of the FRP joint 2. Leave it as is for a while. In this case, use adhesive of the same quality. Next, apply the same method to the socket 2c on the opposite side of the FRP joint 2.
Connect the FRP composite pipe 1.

Note that when the FRP composite pipe 1 and the FRP joint 2 are bonded together, a portion of the inner core layer 1a of the FRP composite pipe is exposed to the outside of the FRP joint 2.

Next, move on to the third step.

The third step is to cover the outside of the joint between the FRP composite pipe 1 and the FRP joint 2 with reinforced plastic to reinforce the joint. First, the joint B between the FRP joint 2 and the FRP joint 1 is coated with acetone. Wipe it off with a solvent such as Solvent treatment can remove substances that inhibit the adhesion effect, such as mold release agents and dust during molding, and
A fine uneven pattern can be formed on the surface of the connecting portion B, thereby increasing the adhesion effect. After solvent treatment, an adhesive primer is used on the connection B. The primer used in this example is a solution-based surface treatment agent in which a resin component consisting of a vinyl chloride monovinyl acetate copolymer mixed with a trace amount of di-2-ethylhexel phthalate is dissolved in a solvent mixture of methyl ethyl ketone and a trace amount of toluene. And,
It has the effect of increasing the adhesive force between vinyl chloride resin and unsaturated polyester resin, and as mentioned above, it
The primer applied to a part of the inner core layer 1a of the composite pipe 1 strongly bonds with the thermosetting resin on the reinforcing sheet 12 made of a reinforced plastic sheet covered from above, and strongly adheres to the vinyl chloride resin. It is something that will be done. After applying the adhesive primer and air-drying, if there is a step in the connecting portion B, as shown in FIG. 3, putty 13 is applied to eliminate the step.
This putty 13 is prepared by adding a curing accelerator to a polyester resin and adding calcium carbonate thereto, and the curing agent is added at the time of use.
Once putty 13 is applied to the stepped portion and hardened, a reinforcement sheet 12 for reinforcement is wrapped around it.

The reinforcing sheet 12 is a photosensitive unsaturated epoxy ester resin composition, and an example of its components is glass mat 38% by weight, ethanol 35% by weight, styrene monomer 10% by weight, and the remainder is unsaturated epoxy ester resin. It is composed of trace amounts of photosensitizer, polymerization inhibitor, thickener, etc., and is in the form of a sheet made of glass mat as a base material and impregnated with the above-mentioned unsaturated epoxy ester resin composition.
It is soft and rolled into a tape shape for easy handling, and is stored in a case that blocks light when not in use. Moreover, since this reinforcing sheet 12 is photocurable, it has the property of being hardened within a short time by irradiation with light such as sunlight, a fluorescent lamp, an incandescent lamp, or the like.

Fig. 3 shows the state in which the reinforcing sheet 12 is wound around the connection part B between the FRP composite pipe 1 and the FRP socket joint 2. The reinforcing sheet 12 is rolled up from one end of the FRP socket joint 2, and the reinforcing sheet 12 is gradually wrapped around the end surface. Roll it up so that it overlaps, press it down with your hand, and turn it over the connection part B. In this example, four layers of the reinforcing sheet 12 were rolled up and left under sunlight for approximately one hour to be completely cured.

By connecting the FRP composite pipe 1 and the FRP socket joint 2 as described above, and reinforcing the connection part B from the outside with the reinforcing sheet 12, all the inner pipe parts through which various high-temperature solutions pass will have excellent corrosion resistance. Since it is made of vinyl chloride resin, the inner tube will not deteriorate even when high temperature acid/alkaline solutions are passed through it, and since no glass fiber is used in the inner tube, there will be no leakage of the solution due to capillary action. do not have.

Although some of the embodiments have been described above, the present invention
This embodiment is by no means limited to such examples; for example, in an FRP composite pipe, a reinforced plastic layer made of a thermosetting resin and glass fiber is fixed to the outside of an inner core layer made of a thermoplastic resin.
All types of fittings required for piping, such as layered structures, FRP fittings, elbows, cheese bends, etc., are included. In addition, a reinforced sheet 12 that also reinforces the connection part
The components are not limited to the examples, but include unsaturated epoxy ester resin, a solvent, a thickener, a polymerization inhibitor, a sensitizer, a curing accelerator, etc., kneaded to a viscosity that is easy to use, and then impregnated into glass fibers. As long as it can be cut to an appropriate length and width for use, it can be freely selected and used by changing its components and mixing.

As explained above, according to the present invention, the following effects can be achieved.

(a) All the pipes through which various solutions pass are made of corrosion-resistant thermoplastic resin, which prevents deterioration due to thermal deterioration and corrosion. Furthermore, since no glass fibers are used at all on the pipe surface through which the solution passes, there is no danger of the solution leaking out to the outside of the FRP composite pipe through the glass fibers.

(b) The light-curable reinforcing sheet easily reinforces the joints of FRP composite pipes and has an excellent reinforcing effect, so the FRP composite pipes do not come off from the joints as before, and on-site construction is possible. Easy to do
It can greatly contribute to the spread of FRP composite pipes.

Furthermore, by using the planer according to the embodiment of the present invention, the reinforcing plastic on the inner core layer can be completely scraped off, so there is no deformation of the inner core layer due to heating unlike in the past, and the adhesive force with the joint is increased. Furthermore, the time required to remove the reinforced plastic can be greatly reduced.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the cutting state of the reinforced plastic layer of the FRP composite pipe according to the method of the present invention, Fig. 2 is an explanatory diagram showing the connection state of the same FRP composite pipe and FRP joint, and Fig. 3 is an explanatory diagram showing the state of the connection between the FRP composite pipe and the FRP joint according to the present invention. FRP by method
FIG. 4 is a side view of a planer used in the method of the present invention, and FIG. 5 is a bottom view of the same. 1: FRP composite pipe, 1a: inner core layer, 1b: reinforced plastic layer, 1c: covering layer, 2: FRP joint,
2a: PVC resin joint, 2b: Reinforced plastic layer, 2c: Socket portion, 12: Reinforced sheet.

Claims (1)

[Claims] 1 The reinforced plastic layer at the end of the FRP composite pipe is scraped off to a required length to expose the inner core layer made of thermoplastic resin, and then a reinforced plastic layer is placed on the outside of the PVC resin joint to create an FRP joint. Apply adhesive to the inner surface of the socket and the outer surface of the inner core layer, insert the inner core layer into the socket of the FRP joint to connect them, and then apply adhesive to the outer surface of the connection between the FRP composite pipe and the FRP joint. After wiping with a solvent and applying a primer made by dissolving a resin whose main component is vinyl chloride monovinyl acetate copolymer in a solvent and drying it,
A flexible reinforcing sheet made by impregnating glass fibers with a photo-curable resin whose main component is unsaturated epoxy ester resin is wound over the glass fibers, and the fibers are irradiated with light to harden and connect. Features: How to connect FRP composite pipes.