JPS5991024A - Method of covering pipe - Google Patents

Abstract

PURPOSE:To obtain a covering that has a positive corrosion prevention effect and is free from any stepped part of a covering layer and an adhesive layer that have approximately the same width and are wound together, by winding helically the covering layer and the adhesive layer on a pipe extruded from a die with parts of the covering layer and the adhesive layer overlapped. CONSTITUTION:The openings 13, 14 of paths 10, 11 at the discharging section of a die 5 for resins that will form the covering layer and the adhesive layer respectively are formed into horizontally extending rectangles whose widths have approximately the same dimension, with them displaced laterally and parts thereof in communication with each other vertically. The covering layer 6 and the adhesive layer 7 that are extruded from the die 5 with parts thereof overlapped are wound helically on the pipe 15 that is rotated circumferentially with the adhesive layer 7 inside. First, layers 6a, 7a are wound on the pipe 15, then layers 6b, 7b are wound so that any stepped part would not be formed. The peripheries of the adjacent covering layer 6 and adhesive layer 7 are displaced enough thereby providing a positive corrosion prevention effect.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for coating (j'e), and more particularly to a method for coating a tube by wrapping a coating layer around the outer circle of the tube.

Conventionally, in order to protect the outer surface of the pipe, Japanese Patent Application Laid-Open No. 14848
As shown in Japanese Patent Application No. 8+3, there is a method in which a coating JgJ and an adhesive layer are overlapped with a tie, extruded into a band shape, and this band is wound spirally around the outer surface of a tube. By the way, in the case of conventional products such as the one shown in FIG. It is customary to wrap the tube (3) in a 1 ton shape with the tubes (3) partially overlapped. Therefore, a stepped portion (4) as shown in FIG. 5 is generated, and there is a time r1 in which the outer diameter of the tube (3) becomes larger than necessary. In addition, when wrapping the side edges of adjacent tubes facing each other in order to prevent the formation of stepped portions (4), gaps are created between the side edges of the tubes (3).
There is a risk that the anticorrosion effect of

SUMMARY OF THE INVENTION The object of the present invention is to solve these problems, prevent the formation of stepped portions, and provide a reliable anti-corrosion effect.

In order to achieve this object, the present invention consists of a coating layer and an adhesive layer having approximately the same width, which are shifted from each other in the width direction so as to partially overlap each other.
The strip is extruded from a die and wound spirally around a tube, with the adhesive layer facing inside and the side edges of the adjacent sheaths 1411 facing each other and the side edges of the adjacent adhesive layers facing each other.

Therefore, it is possible to prevent the formation of steps as in the conventional case, and the side edges of the adjoining coating layers and the side edges of the gapping adhesive layer can be positioned with a sufficient distance between them, resulting in a reliable corrosion prevention effect. This is something that can be obtained.

An embodiment of the Itogi invention will be described based on FIGS. 1 to 4. In Figure Qj41 to Figure B, (5) is a die for extruding the 6u covering layer (6) and the adhesive layer (7) (see Figure 4), and the die that extrudes the 6u covering layer (6) and the adhesive layer (7) (see Figure 4). A screw set extruder 0 (8) for extruding the resin and a screw set extruder (9) for extruding the resin for forming the adhesive layer (7) are connected. The extruder (8) includes this extruder (3).
) for extruding the resin from the die (5). A resin passage 0 (blue line is connected to il, and a similar resin passage 01) is connected to the extruder (9). Discharge part 0 of die (5)
Opening 0 of both passages (IF Chin 01) at 9: IO Ruha,
They are formed into horizontally elongated rectangles having the same horizontal dimension, and are shifted from each other in the horizontal direction by 1'iJJ, with some portions being continuous in the vertical direction.

I will explain how to apply it. Activate the extruder (8) and extrude the rci Jrl (o) from +: 6 in a heated state to create its (1st)
! ill to extrude the adhesive layer (7) in a heated state.

Then? I! 71','The L layer (0) and the adhesive layer (7) have approximately the same width and are partially overlapped with each other in the horizontal direction, and are formed from the die (5) to (1). In this example, both layers (it) (7) are shifted by a width dimension σ) 1/2 in the width direction.

Note that polyethylene, polypropylene, vinyl chloride, nylon, etc. may be used as the wood 11)j forming the covering layer (6). Further, as the resin forming the adhesive layer (7), chemically modified polyethylene, chemically modified polypropylene,
Use something that has adhesive properties, such as vinyl chloride.

As described above, the first layer V1 (6) and the adhesive layer (7) are extruded from the tie (5) in a circumferential direction with the adhesive layer (7) on the inside as shown in FIG. Wrap it in a spiral around the rotating tube 0 sieve. That is, first, the layer ('
6a) ('Ia) is wrapped around il, then (6b
') (7b) or (6c) (7c'), the side edges of the W B (6) that are examined each other and the side edges of the adhesive layers (7) that are adjacent to each other face each other. First, it is wrapped around the pipe OQ. Incidentally, since the coating layer portion H at the beginning of winding protrudes from the end of the tube Qυ, it is reduced to Fi'ISn.

If you do it like this? i! The side edges of the first layer (6) and the (1!!I k-9) of the adhesive layer (7) are alternately arranged along the axial direction of the tube (1), and the fifth It is possible to prevent the formation of a stepped portion (4) due to heavy AA winding like the one shown in the figure.
0 of the adhesive layer (7) that meets the side edge of the layer (6) 191i
11i edges and 17. It is possible to achieve reliable corrosion prevention 11 (11) when it is time to use the soup.In addition, as shown in Figure fPJ4, it is possible to
If the width of the first layer (6) is made slightly larger than the width of the adhesive layer (7), the side edges of the coating layer (6) will be pushed out, thereby preventing water stoppage, etc. is more reliable and more effective.

As described above, according to the present invention, it is possible to prevent the generation of stepped portions as in the conventional case, and furthermore, the side edges of adjacent coating layers and VW
Since the side edges of the adhesion layers that meet each other can be positioned with a sufficient distance from each other, a reliable anti-corrosion effect can be obtained.

[Brief explanation of the drawing]

1 to 5 show one embodiment of the present invention, in which FIG. 1 is a perspective view of the tie, FIG. 2 is a cross-sectional side view thereof, FIG. 3 is a vertical cross-sectional plan view thereof, and FIG. (Figure 5 is a diagram showing a y-shaped IL9, FIG. 5 is a diagram showing a conventional example-0) winding (t Ct-shaped MJ. (5) Die, (li) (6a) (6b)-:
'I'J VGJ layer, (7) (7a) ('7b)
・-・Adhesive layer, 0su・Management agent Moriki 1i
Figure 1/j Figure 3 Figure 4 Tonen Petrochemical Co., Ltd., 4-1-1 Tsukiji, Chuo-ku, Tokyo (Applicant: Yokohama Chemical Machinery Co., Ltd., 4-6-13 Tsunashima, Kohoku-ku, Yokohama) (Applicant: Tonen Petrochemical Co., Ltd. 4-1-1 Tsukiji, Chuo-ku, Tokyo

Claims (1)

[Claims] 1. A covering layer and an adhesive layer of approximately the same width are built up evenly in the width direction, partially overlapping each other, and extruded from a die into a band shape.
A method for coating a tube, characterized by wrapping the tube in a helical manner with the adhesive layer on the inside, the side edges of adjacent coating layers facing each other, and the side edges of adjacent adhesive layers facing each other.