JPH0356177B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a synthetic resin film on the surface of a long tube.
The present invention relates to a method of manufacturing a laminated tube coated with an adhesive or the like, and particularly to a method of manufacturing a laminated tube that can continuously and stably obtain a plurality of laminated tubes of stable quality.

Conventionally, when inserting and lining a laminated pipe whose surface was coated with a synthetic resin film, adhesive, etc. onto the inner surface of a steel pipe, etc., the coating on the end surface of the long pipe peeled off during insertion, resulting in failure of the lining. It was possible to become complete.

In order to solve the above-mentioned drawbacks, the present invention found that it is preferable to use a laminated tube in which the end face of the long tube is covered with a coating, and the laminated tube can be obtained continuously and stably. The company has discovered a manufacturing method, and its gist is that in a method of sequentially forming a coating on the outer circumferential surface of a long tube that has been cut into a predetermined length, The first feeding machine 1, the second feeding machine 3, the coating device 4, the take-up machine 6, and the cutting machine 7 are arranged in this order, and a certain interval is left between the first feeding machine 1 and the second feeding machine 3 on the long pipe. , while always maintaining a constant distance between the end faces of adjacent long tubes, the coating is continuously coated and laminated on the outer peripheral surface of the long tube through the coating device 4, and the laminated tube is taken up by a take-up machine 6. The method of manufacturing a laminated pipe is characterized in that a cutting machine 7 then cuts the covering between the end faces of adjacent long pipes.

Examples of the long pipe in the present invention include metal pipes such as steel pipes, galvanized steel pipes, and aluminum pipes, and synthetic resin pipes such as polyvinyl chloride pipes and polyethylene pipes. In addition, materials that can be extruded to coat long pipes include synthetic resins such as polyethylene, polypropylene, and polyvinyl chloride, as well as polyethylene, ethylene-vinyl acetate copolymers, polyamide resins, and polyester resins. There are hot melt adhesives used as base materials.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the equipment used in the present invention as a flow diagram.The main configuration of the equipment will be explained from the long pipe supply side.The first feeder 1 and the second feeder 3 are The purpose of the present invention is to supply the end surfaces of adjacent long tubes to the coating device 4 for the next step in a state in which the end surfaces are always maintained at a constant distance. The above-mentioned first feeder 1 is designed to keep the interval between the long tubes fed constant up to the second feeder 3, and the speed needs to be set slightly slower than that of the second feeder 3. By doing this, even if the long tubes are continuously fed into the first feeder 1 with their end faces abutted, the intervals will gradually open up and the tubes will be sent to the second feeder 3 at regular intervals. . Second feeder 3
is for supplying long tubes at regular intervals to the coating device 4 in the next step at a constant speed, and is set at the same speed as the coating speed of the coating device 4. The distance between the first feeder 1 and the second feeder 3 may be slightly wider than the length of one long tube used.

The purpose of the coating device 4 and the crimping equipment 5 is to uniformly and continuously coat the outer circumferential surface of the long tube with the coating, and it is necessary to completely adhere the coating to the outer circumferential surface of the long tube. The coating device 4 is generally suitable for a melt extrusion coating method using an annular crosshead die.
Furthermore, a film winding method using an arm type winding machine can also be used. The crimping equipment 5 is for tightly adhering the coating to the long tube, and a crimping method using rolls or air can be applied.

The purpose of the pulling machine 6 and the cutting machine 7 is to cut the coating between the end faces of adjacent coated long tubes. The take-off machine 6 takes over the coated long tube, that is, the laminated pipe, at a constant speed, which is basically the same speed as the second feeder 3, and may be a roll-type or a caterpillar-type take-off method.

The purpose of the cutting machine 7 is to cut the coating between the end faces of the long tube that is continuously fed. The cutting method generally uses a cutting blade, but various other cutting methods can also be applied. When cutting, it is necessary to accurately detect the end face positions of adjacent long tubes, but according to the method of the present invention, since the long pipes are maintained at a constant distance, the end face positions can be easily detected. It is extremely easy to detect and allows accurate cutting without shifting the cutting surface.

In addition, since the coating is cut between the end faces of the long pipe, the end face of the long pipe after cutting is covered with the coating, resulting in a laminated pipe with stable quality that is easy to line with steel pipes, etc. is obtained.

Note that the guide 2. shown in FIG. about,
This is to send the laminated tube to the next process without causing problems such as misalignment of the end faces of the laminated tube between each device or damage, etc.It allows long tubes to be fed smoothly and prevents scratches in the long tube. Consists of multiple free rolls made of materials that do not cause

Next, the present invention will be explained in more detail with reference to Examples.

PVC pipe (outer diameter 50mm) is used as a long pipe.
φ), a polyethylene-based hot melt adhesive was used as the coating, and extrusion coating was performed to a thickness of 100μ. The configuration of the manufacturing equipment is substantially the same as that shown in FIG. 1 above. The first feeder 1 uses a torque motor, and the feeding speed of the long tube is set to 49 m/min, and the set speed of the second feeder 3 is
The speed was 50m/min. The distance between the first feeder 1 and the second feeder 3 was made somewhat wider than the length of one long tube. Although the long tubes were continuously fed into the first feeder 1, there was a gap of about 10 cm between the tubes and the second feeder 3, allowing them to be transferred to the next process. Coating device 4 uses an extrusion coating device using a crosshead die, and the coating speed is increased.
It was set at 50m/min. Similarly, the set speed of the crimping equipment 5 and the take-off machine 6 was set to 50 m/min.

Further, the cutting machine 7 detected the end faces of the long tubes using a phototube, operated a cutting blade, and cut the coating between the end faces of adjacent long tubes. The speed of the cutting machine 7 is the same as that of the pulling machine 6 in the previous process.

With the arrangement of the equipment and the set speeds described above, it is possible to manufacture the long tube without causing any trouble such as damage to the long tube itself, and it is possible to stably obtain a laminated tube whose end face is completely covered with the coating. It can be suitably used as a laminated pipe for lining the inner surface of a steel pipe.

[Brief explanation of drawings]

FIG. 1 is a flow diagram showing an example of equipment used in the present invention. 1...First supply machine, 3...Second supply machine, 4...
Coating device, 6...taking machine, 7...cutting machine.

Claims (1)

[Claims] 1 In a method of continuously and sequentially forming a coating on the outer circumferential surface of a long tube cut into a predetermined length in advance, from the supply side of the long tube, a first feeder 1, a second feeder 3, a coating device 4, The pulling machine 6 and the cutting machine 7 are arranged in this order, and a constant distance is maintained between the first feeder 1 and the second feeder 3 in the long tube, and a constant distance is always maintained between the end faces of adjacent long tubes. While holding the tube, the coating is continuously coated and laminated on the outer circumferential surface of the long tube through the coating device 4, and the laminated tube is taken up by a take-off machine 6, and then cut between the end faces of adjacent long tubes by a cutter 7. 1. A method for manufacturing a laminated pipe, the method comprising cutting the covering of the laminated pipe.