JPH03169617A - Sheet for coating and coating method utilized therewith - Google Patents

Abstract

PURPOSE:To surely coat a thermal shrinkable sheet on a body such as a pipe by forming a pair of stopping parts on both the surface of one end part in the lengthwise direction of a sheet main body and the other surface of the other end part thereof respectively and constituting the stopping parts so that these are mutually stopped. CONSTITUTION:At least one part of the lengthwise direction of a flexible sheet main body 1 is formed of a cross-linked polymer which is uniaxially oriented in the lengthwise direction thereof. This sheet main body is wound at one round on a body such as a pipe. A pair of stopping parts 6 are mutually stopped which are formed respectively on both the surface of one end part 2 in the lengthwise direction of this sheet main body and the other surface of the other end part thereof. The sheet main body is thermally shrunk by heating the cross- linked polymer and closely stuck on the surface of the body such as the pipe to coat it. The stopping parts 6 have the stopping faces 5a tilted to the inner parts of the lengthwise direction as the stopping parts 6 withdraw to the direction of thickness from the surface of the sheet main body. The stopping faces are allowed to abut with each other and a stopped state is achieved. Accordingly even in a state wherein the sheet main body is wound on the curved surface of the outer circumferential face of the pipe, etc., the stopped state is surely kept wherein the stopping faces are allowed to abut. Further an adhesive 7 is applied to the stopping parts 6 and thereby the joining strength of both end parts of the sheet main body is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a coating that can be used, for example, for corrosion protection near the pipe joints of pipes that transport fluids such as gas and water, and for repairing the corrosion protection layer of existing pipes. This paper relates to a protective sheet and a coating method using the same. BACKGROUND OF THE INVENTION In order to provide such a coating, a heat-shrinkable sheet is used, which makes it possible to seal the outer surface of the tube airtight. A typical prior art is disclosed in Japanese Patent Application Laid-Open No. 56-35893. In this prior art, a heat-shrinkable sheet is wrapped around the outer periphery of a tube, the circumferential ends of the wrapped state are partially overlapped and bonded using an adhesive, and then the heat-shrinkable sheet is heated to shrink the heat-shrinkable sheet. ．． In such prior art, shearing and peeling forces act due to the shrinkage force of the heat-shrinkable sheet when it is heat-shrinked, causing adhesive joints to peel off during installation, and residual shrinkage forces constantly causing shearing and peeling forces after installation. Due to the force of peeling, durability is poor, especially when used under high temperature conditions. Other prior art is disclosed in Japanese Patent Application Laid-Open No. 60-34829. In this prior art, pins are inserted into both ends of the heat-shrinkable sheet to join it. Other prior art is disclosed in Utility Model Application Publication No. 57-44293. In this prior art, a large number of fine loops are planted on one end of a heat-shrinkable sheet, and a large number of hooks that are hooked on the loops are planted on the other end, and the loops and the hooks are connected to each other. Perform the joining. In each of these prior art, the joint structure is relatively complicated, the productivity is poor, and there is a risk of damage to the joint part when excessive bending force or excessive tightening force is applied. be. Furthermore, there is a problem in that the bonding strength is insufficient, and therefore the stress during contraction of the heat-shrinkable sheet is reduced, resulting in a reduction in sealing performance. Still other prior art is disclosed in JP-A-57-120417 and JP-A-61-274198. In these prior art techniques, both ends of the heat-shrinkable sheet are sandwiched and fixed with metal fittings. Even with such prior art, the construction is relatively complicated, and the metal fittings may be damaged due to excessive bending force and tightening force, and there is a risk that the sealing performance may deteriorate due to stress relaxation. Problems to be Solved by the Invention An object of the present invention is to provide a covering sheet that can reliably cover objects such as pipes with a heat-shrinkable sheet, and a covering method using the same. Means for Solving the Problems The present invention provides a flexible sheet body, at least a portion of which is made of a crosslinked polymer uniaxially stretched in the longitudinal direction, and one surface of one longitudinal end of the sheet body. This is a covering sheet characterized in that it has a pair of locking portions formed on the top surface of the cover and the other surface of the other end portion and locking each other. Further, the present invention is characterized in that the locking portion has a locking surface that slopes inwardly in the longitudinal direction as it gets farther away from the surface of the seat body in the thickness direction. Further, the present invention is characterized in that the surface of the locking portion is coated with an adhesive, and the locking portion has a height that is greater than the thickness of the adhesive layer. Further, the present invention is characterized in that the locking portion does not have heat shrinkability. The present invention also provides a coating method for covering an object using a coating sheet, wherein the coating sheet is (a) at least a portion in the longitudinal direction made of a flexible crosslinked polymer uniaxially stretched in the longitudinal direction; (b) a pair of locking portions that are formed on one surface of one end in the longitudinal direction of the seat body and the other surface of the other end thereof and that lock each other; With the locking part locked with an adhesive interposed between the locking parts, the vicinity of the locking part is heated to make the covering sheet into a cylindrical shape, and then the cylindrical covering sheet is coated with: This coating method is characterized in that the remaining portion of the covering sheet other than the locking portion is heated to cover the object with the covering sheet while the object to be covered is inserted through the covering sheet.

Further, in the present invention, an adhesive is interposed between the inner circumferential surface of the cylindrical covering sheet and the outer circumferential surface of the object, and in this state, the remaining portion of the covering sheet other than the locking portion is heated. It is characterized by

Function The covering sheet according to the present invention has a visible sheet main body and a pair of locking parts, and the flexible sheet main body has at least a portion of the flexible sheet main body formed of cross-linked material that is uniaxially extended in the longitudinal direction. The pair of locking portions are made of polymer and are formed on one surface of one end of the sheet body in the longitudinal direction and the other surface of the other end thereof, and are capable of locking each other.

Therefore, the main body of the visibility sheet is wrapped around the outer peripheral surface of the object to be covered, for example, a pipe, approximately l times, the pair of locking portions are locked to each other, and then the uniaxially stretched crosslinked polymer is heated. Heat shrinkage is performed by In this way, the flexible sheet body can be wrapped tightly around the outer peripheral surface of the tube to cover it.

According to the present invention, the locking portion has an inclined surface that slopes inward in the longitudinal direction as it goes away from the surface of the seat body in the thickness direction, so that a so-called return-like projection is formed. The locking parts of the respective locking parts abut each other, so that the locked state is reliably maintained even when the flexible sheet body is wrapped around the outer peripheral surface of the tube. Adhesive is applied to the surface of the locking part, so the locking part is also fixed by the adhesive.
This locking part has a height that is greater than the thickness of the adhesive layer, so
A pair of locking parts can be reliably locked to each other. Although the locking portion may have heat-shrinkability, it does not need to have heat-shrinkability.

Further, in the coating method according to the present invention, with an adhesive interposed between the locking portions of the covering sheet and the locking portions being locked, the vicinity of the locking portions is ripened, thereby stopping the locking portions. Can be fixed by adhesive. In this way, the covering sheet is made into a cylindrical shape. The sheet main body of this covering sheet may be wrapped around a tube or the like and the locking portions may be fixed to each other as described above, or the sheet body may be formed into a tube shape and then the tube may be inserted therethrough. Next, with a tube inserted through the cylindrical covering sheet, the remaining portion of the covering sheet other than the locking portion is heated to heat-shrink the crosslinked polymer. In this way, the outer peripheral surface of an object such as a pipe is covered with the covering sheet.

Furthermore, according to the present invention, an adhesive is interposed between the inner circumferential surface of the cylindrical covering sheet and the outer circumferential surface of an object such as a pipe, and the bonding is performed as the covering sheet shrinks due to heat. You can.

Embodiment FIG. 1 is a perspective view of an embodiment of the present invention. This covering sheet 1 includes an elongated visible sheet main body 2 extending in the longitudinal direction (left-right direction in FIG. 1), and a pair of locking parts 5 formed at both ends of the sheet main body 2 in the longitudinal direction.
．． 6, and is made of a crosslinked polymer that is uniaxially stretched in the longitudinal direction (the left-right direction in FIG. 1), such as crosslinked polyethylene, crosslinked polypropylene, crosslinked fluororubber, fluororesin, and crosslinked silicone rubber. The thickness of this sheet body 2 is, for example, 1 to 3 mm. One of the locking parts 5 is
A shape protruding from one surface (lower surface in FIG. 1) of one longitudinal end (right end in FIG. 1) of the sheet body 2, and a plurality of (this) In the example, 3) Form precepts are given. Another locking part 6 is the seat body 2
It is formed in a raised manner on the other surface (top surface in FIG. 1) of the other end (left end in FIG. In the example, one less number is formed for 3> or for the one that is on the inside at the time of locking.

The locking portion 5 moves further inward in the longitudinal direction (to the left in FIG. 1) as it gets further away from the one surface of the sheet body 2 in the thickness direction (vertical direction in FIG. 1), that is, as it moves downward in FIG. It has a locking surface 5a that is inclined in the direction (direction). The other locking portion 6 also has a locking surface 6a. An adhesive 7 is applied to the surface near one of the locking portions 5 over a distance l1 in the direction of the grip. The height of the locking portion 5 is t2 compared to the thickness t1 of the layer of adhesive 7 (tl<t2), so that the stop portions 5 and 6 are arranged so that the locking surfaces 5a and 6a face each other with the adhesive 7 interposed therebetween. It can be locked by The height t2 of the locking portion 5 is preferably 0.5 to 2 times the thickness t3 of the seat body 2.
The locking surface 5a of the locking portion 5 and the flat raised surface 5 of the locking portion 5
The angle θ formed with b should be 90 degrees, but
Preferably it is 30 to 80 degrees. Since the angle θ is less than 90 degrees, the locking of the locking portion 5.6 is reliably maintained when the sheet body 2 is coated on a curved surface such as a pipe. The locking portion 6 has a similar configuration to the locking portion 5 described above.

FIG. 2 shows that using the covering sheet 1 shown in FIG.
FIG. 3 is a cross-sectional view showing the procedure of a coating method for coating a pipe 10 such as a steel plate that transports fluid. Referring to FIG. 2(1), a coating layer 15 is formed on the tube 10 in advance, and this tube 10
An adhesive 16 is applied to the portion 10a to be coated. The work of joining both ends 3 and 4 of the sheet main body 2 is carried out in the axial direction from the portion 10a of the pipe 10 to be covered in FIG.
Perform this at a position shifted to the left of 1). Figure 2 (2) shows the second
FIG. 2 is a cross-sectional view taken from section line ■--■ in FIG. (1). tube 1
0, the sheet main body 2 is covered, the ends 3 and 4 thereof are overlapped, and the locking surfaces 5a and 6a are locked through a layer of adhesive 7. FIG. 3 is an enlarged sectional view showing a state in which the locking portions 5 and 6 are locked through a layer of adhesive 7 and bonded together by the adhesive 7. When this is done, the inner diameter of the cylindrical sheet body 2 is larger than the outer diameter of the tube 10,
A gap 12 exists.

Therefore, the flat electric heaters 13 and 14 with visibility are
It is pressed against the ends 3, 4 of the sheet main body 2, and in this way, the ends 3, 4 are heated to partially heat shrink the sheet main body 2, and the locking portions 5.6 are locked. At the same time, it is bonded with adhesive 7. The adhesive 7 may be a thermoplastic synthetic resin material that is fluid when heated and solidifies or becomes tacky below the applicable temperature at which the fluid is transported in the tube 10, or once heated. Although the viscosity decreases, it may also be a mature hardening synthetic resin material that hardens by reaction. Specifically, such adhesive 7 includes butyl rubber,
Examples include epoxy resin and unsaturated polyester resin. Therefore, the electric heaters 13 and 14 are removed, the cylindrical sheet main body 2 is moved to the part 10a to be covered, and
As shown by I(3), the remaining portions of the sheet body 2 other than the end portions 3 and 4 are heated using a burner 17, and the sheet body 2 is thus thermally shrunk. As a result, the outer peripheral surface of the tube 10 is covered with the sheet body 2 via the adhesive 16. Adhesive 16 may be omitted.

FIG. 4 is a perspective view of a covering sheet 20 according to another embodiment of the present invention. This covering sheet 20 has a structure similar to the IL covering sheet 1 shown in FIG.
Corresponding parts are given the same reference numerals. It should be noted that in this embodiment, the adhesive 7 is applied over the entire surface of the sheet body 2, while the locking portion 5 is fixed. The pipe 10 is coated with the covering sheet 20 shown in FIG.
5(1), the ends 3 and 4 of the sheet body 2 are overlapped and locked, and a rigid metal plate 21 made of a material such as iron is placed over the end 4. It is heated by the burner 22.

As a result, the locking parts 5 and 6 are bonded in a locked state. After that, as shown in FIG. 5 (2), the burner 23,
24 to heat the remaining portion of the sheet body 2 to cause it to shrink. As a result, coating is performed with the adhesive 7 filled between the outer peripheral surface of the tube 10 and the inner peripheral surface of the cylindrical sheet body 2.

FIG. 6 is a side view of another embodiment of the invention.

In this embodiment, the length 12 of the ends 3 and 4 of the seat body 2 is
．． Part 13 does not have heat shrinkability, and the remaining length is 1
The part extending over 4 has heat shrinkability. The portions that do not have heat shrinkability over the length e2.13 of the ends 3 and 4 are preheated to shrink a crosslinked polymer that has been uniaxially stretched in the longitudinal direction (left and right directions in FIG. 6). Or, it is shaped into a sheet without being stretched. FIG. 7 is a sectional view of another embodiment of the present invention. In this embodiment, one locking portion 5, 6 is formed at the end portions 3, 4 of the seat body 2, and therefore the locking portions 5, 6 are locked as shown in FIG. At the same time, they are bonded together via a layer of adhesive 7.

FIG. 9 is a sectional view of still another embodiment of the present invention.

This embodiment is similar to the previously described embodiment of FIGS. 7 and 8, and corresponding parts are provided with the same reference numerals. It should be noted that in this embodiment, a layer of adhesive 7 is formed on the sheet body 2 not only near the end portion 5 but also over the entire surface where the locking portion 5 is formed.

No. 101117I is a sectional view of a covering sheet 23 according to still another embodiment of the present invention. This seat body 24 is
It is made of the same material as the seat body 2 described above. A locking recess 27 facing one surface is formed at one end 25 and the other end 26 of the seat body 24, and the locking recess 27 has a locking surface 27a. The other end 26 is shaped with a locking protrusion 28 that is fitted into the locking recess 27 and locked, and this locking protrusion 28 has a locking surface 28a that comes into contact with the locking surface 27a. has. FIG. 11 is a plan view of this locking recess 27.

A plurality of locking recesses 27 are formed at intervals in the width direction of the sheet body 24 (perpendicular to the plane of the paper in FIG. 10, vertical direction in FIG. The locking recess 27 contracts as shown in FIG. FIG. 12 is a plan view of the locking projection 28. The locking protrusions 28 are spaced apart from each other in the width direction of the seat body 24 (in the vertical direction in FIG. 12) in correspondence with the locking recesses 27. Therefore, as described above, heat shrinkage is performed by heating the ends 25 and 26 with the locking protrusion 28 fitted into the locking recess 27, and the locking surface 27a 28
a comes into contact and the ends 25 and 26 are joined. Effects of the Invention As described above, according to the present invention, at least a portion of the longitudinal direction of the visibility sheet body is made of a crosslinked polymer uniaxially stretched in the longitudinal direction, and the sheet body is attached to an object such as a pipe. The crosslinked polymer is wound approximately once so that a pair of stop portions formed on one surface of one end and the other surface of the other end in the longitudinal direction of the sheet body are mutually locked, and the crosslinked polymer is heated. This allows the sheet to shrink tightly and cover the surface of an object such as a pipe by heat shrinking. Therefore, it is possible to securely connect both ends of the seat body in the longitudinal direction at the locking portion, and it is easy to improve durability. Furthermore, the configuration of the locking part is simple and superior to produced bamboo, and it is possible to cover the surface of the object with the JET body in close contact for a long period of time, thereby achieving long-term corrosion protection. can do.

Particularly, according to the present invention, the locking portion has a locking surface that is inclined inward in the longitudinal direction as the distance from the surface of the jet main body increases in the thickness direction, and the locking surfaces abut each other. A locked state is achieved. Therefore, even when the sheet body is wrapped around a curved outer circumferential surface of a pipe or the like, the locked state in which the locking surfaces are in contact is reliably maintained. Further, adhesive can be applied to this locking portion to improve the bonding strength between both ends of the sheet body.

Furthermore, according to the present invention, the vicinity of the locking portion is heated with the locking portion being locked with an adhesive interposed between the locking portions, and the covering sheet is thus formed into a cylindrical shape. The object to be covered, such as the object to be covered, is inserted into the cylindrical covering sheet, and the part made of the crosslinked polymer is heated to cause heat shrinkage.
This allows coating to be performed with good workability. In this way, a durable bond is achieved even when shearing and peeling forces are applied to the lock. In addition, it does not require the bottles and the like in the prior art, and has a simple structure, so productivity is excellent and manufacturing costs can be reduced.

Furthermore, in the present invention, large protrusions such as the metal fittings that fix both ends of the sheet body in the prior art described above do not protrude onto the surface of the coating layer, and therefore are not damaged by external forces. There is no damage, and the coating can be reliably maintained for a long period of time. In addition, even if the environment is high temperature, the locked state of the pair of locking parts is maintained, and even during long-term shear creep due to residual stress in the seat body, the locked state will not come off, and the seat body will remain locked. The contact between both ends is maintained reliably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a sectional view showing a method of covering a pipe 10 using the covering sheet 1 shown in FIG. FIG. 4 is a cross-sectional view showing a state in which the locking portions 5 and 6 of the end portions 3 and 4 are locked and fixed and joined by a layer of adhesive 7; FIG. 4 is a perspective view of another embodiment of the present invention; FIG. Figure 5 shows the covering sheet 20 shown in Figure 4.
FIG. 6 is a cross-sectional view of another embodiment of the present invention, FIG. 7 is a cross-sectional view of still another embodiment of the present invention, and FIG. 8 is a cross-sectional view of another embodiment of the present invention. FIG. 7 is a cross-sectional view showing a state in which the locking parts 5 and 6 of the covering sheet are bonded together via a layer of adhesive 7, and FIG. 9 is a cross-sectional view J of another embodiment of the present invention. FIG. 10 is a sectional view of another embodiment of the present invention;
11 is a plan view of the locking recess 27 in FIG. 10, and FIG. 12 is a plan view of the locking protrusion 28 of the embodiment shown in FIG. 10. 1, 20.23... Covering sheet, 2... Sheet body, 3.4... End portion, 5, 6... Locking portion, 5a, 6
a... Locking surface, 7... Adhesive, 27... Locking recess, 28... Locking protrusion

Claims (1)

[Scope of Claims] (1) A flexible sheet body, at least a portion of which is made of a crosslinked polymer uniaxially stretched in the longitudinal direction; and one surface of one longitudinal end of the sheet body; 1. A covering sheet comprising a pair of locking portions formed on the other surface of the other end portion and locking each other. (2) The covering according to claim 1, wherein the locking portion has a locking surface that slopes inward in the longitudinal direction as it gets farther away from the surface of the sheet body in the thickness direction. sheet. (3) The surface of the locking portion is coated with an adhesive, and the locking portion has a height greater than or equal to the thickness of the adhesive layer. Covering sheet. (4) The covering sheet according to claim 1, wherein the locking portion does not have heat shrinkability. (5) In a covering method of covering an object using a covering sheet, the covering sheet includes: (a) a flexible sheet body at least a portion of which is made of a crosslinked polymer uniaxially stretched in the longitudinal direction; and (b) a pair of locking portions that are respectively formed on one surface of one end in the longitudinal direction of the sheet body and the other surface of the other end and lock each other, the locking portion With the locking part locked with adhesive in between,
The vicinity of the locking part is heated to make the covering sheet into a cylindrical shape. Next, with the object to be covered inserted through the cylindrical covering sheet, the remaining part of the covering sheet other than the locking part is removed. A coating method characterized in that the object is covered with a coating sheet by heating the portion. (6) An adhesive is interposed between the inner circumferential surface of the cylindrical covering sheet and the outer circumferential surface of the object, and in this state, the remaining portion of the covering sheet other than the locking portion is heated. A coating method according to claim 5, characterized in that: