JPH04235023A - Method for welding laminated resin material - Google Patents

Abstract

PURPOSE:To prevent the mixing of the weld bead of a conductive resin layer with the weld beads of first and second insulating resin layers by allowing the end part of the conductive resin layer to recede from the end part of the first insulating resin layer by a considerable distance and allowing the end part of the second insulating resin layer to recede from the end part of the conductive resin layer by a considerable distance. CONSTITUTION:First insulating resin layers 1, 1 are welded using a welding rod composed of an insulating resin (vinyl chloride resin). In this case, welding is performed using a welding rod 11 whose part 11a becoming the surface of a weld bead is formed in an almost flat state. Subsequently, conductive resin layers 2, 2 are welded using a welding rod composed of a conductive resin wherein a carbon powder is dispersed in a vinyl chloride resin. At this time, since the surface of the weld bead 1a of the first insulating resin layers 1 is almost flat, the conductive resin layers 2 can be easily and certainly welded. Thereafter, second insulating resin layers 3, 3 are welded using a welding rod composed of an insulating resin.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for welding together laminated resin materials in which a conductive resin layer is sandwiched between insulating resin layers on both sides.

0002

[Prior Art] Conventionally, as a method for welding together laminated resin materials in which a conductive resin layer is sandwiched between insulating resin layers from both sides, for example, after forming a groove in the structure shown in FIG. It is known how to weld. The laminated resin material 4 in this conventional example includes a first insulating resin layer (vinyl chloride resin layer) 1 and a conductive resin layer (vinyl chloride resin layer) for electrically detecting the occurrence of pinholes in the corrosion-resistant layer. A resin made by dispersing carbon powder to give conductivity) 2 is laminated, and a second insulating resin layer (
It is formed by laminating a vinyl chloride resin layer (3) which is a corrosion-resistant layer. The end portions of the laminated resin materials 4, 4 are shaved obliquely, and the end portions 5, 4 facing each other,
5 are arranged to form a substantially V-shaped groove 6.

[0003] When welding the laminated resin material 4 with grooves formed as described above, first, an insulating resin (vinyl chloride resin) is welded.
The first insulating resin layers 1, 1 are welded using a round bar-shaped welding rod (welding material), and then a conductive resin welding rod (welding material) in which carbon powder is dispersed in vinyl chloride resin is The conductive resin layers 2, 2 are welded using the same. Then, the second insulating resin layers 3, 3 are welded using the welding rod made of the above-mentioned insulating resin, thereby welding the conductive resin materials 4 together.

Conventionally, a structure such as a tank having a predetermined structure was manufactured by welding the laminated resin materials 4 in this manner, and a corrosion resistance deterioration detection system (for example, a second insulating material on the inner surface of the tank) was manufactured. A crack occurs in the resin layer 3, and the liquid in the tank permeates into the conductive resin layer 2 through the crack, resulting in conduction between the liquid contact side of the second insulating resin layer 3 and the conductive resin 2. A system for electrically detecting the occurrence of cracks in the second insulating resin layer (corrosion-resistant resin layer) 3 and other deterioration in corrosion resistance is constructed.

[0005]

However, in the conventional welding method, when welding the first insulating resin layers 1, 1,
The end of the conductive resin layer 2 melts and mixes into the weld bead 1a of the first insulating resin layer (this mixed part is hereinafter referred to as a "whisker").
) produces whiskers 2b. The whiskers 2b may even reach the lower surface of the first insulating resin layer 1 (FIG. 7). Further, when welding the conductive resin layer 2, the end of the second insulating resin layer 3 melts and mixes into the weld bead 2a of the conductive resin layer, and also inside the narrow V-shaped groove 6. The surface of the welding bead 2a of the conductive resin layer has an uneven and raised shape, and when welding the second insulating resin layers 3, 3, the welding rod (welding material) of the insulating resin is uniformly applied to the welding part. It becomes difficult to fill the welding material, and the weld bead 2a of the conductive resin layer 2 gets mixed into the gap between the welding materials, causing whiskers 2c. The whiskers 2c may even reach the upper surface of the weld bead 3a of the second insulating resin layer 3 (FIG. 7).

[0006] In this way, the weld bead 2a of the conductive resin layer becomes the weld bead 1a of the first and second insulating resin layers.
3a, the operating surfaces (for example, liquid contact surfaces) of the first insulating resin layer 1 and the second insulating resin layer 3 are electrically connected to the conductive resin layer 2, and the above corrosion resistance deterioration detection system There is a problem that it does not work properly. Furthermore, even if the whiskers 2c of the conductive resin 2 do not reach the operating surface of the second insulating resin layer 3, there is a problem in that an abnormality is erroneously detected if the second insulating resin layer 3 is slightly worn. There is a point.

The present invention solves the above problems, and aims to provide a welding method in which the weld bead of the conductive resin layer does not mix with the weld bead of the first and second insulating resin layers. do.

[0008]

[Means for Solving the Problems] In order to solve the above problems, the method for welding laminated resin materials of the present invention comprises sandwiching a conductive resin layer between first and second insulating resin layers from both sides. In a method for welding laminated resin materials to each other, the ends of the first insulating resin layers of the laminated resin materials to be welded to each other form grooves facing each other at positions close to each other, and
A considerable portion on the end side of the conductive resin layer is removed, and the end thereof is set back a considerable distance from the end of the first insulating resin layer, and the end of the second insulating resin layer is removed. a groove forming step in which a considerable portion of the conductive resin layer is removed and the end thereof is set back a considerable distance from the end of the conductive resin layer; and a groove forming step using an insulating resin welding material. The first insulating resin layers are welded together, and then the conductive resin layers are welded together using a conductive resin welding material, and the weld bead generated by welding the conductive resin layers is treated to clean the surface. The second insulating resin layer is made substantially flat, and then welding the second insulating resin layers together using an insulating resin welding material.

Further, in the step of welding the first insulating resin layer of the above welding method, a welding rod having a substantially flat surface portion of the first insulating resin layer that will become the weld bead is used to weld the first insulating resin layer. By welding the first insulating resin layer, the surface of the weld bead is made substantially flat.

[0010] The above welding method is also characterized in that it further includes the step of treating the weld bead generated by welding the first insulating resin layers to make the surface of the weld bead substantially flat. .

[0011]

[Function] The ends of the first insulating resin layers of the laminated resin materials to be welded to each other face each other and form grooves, and during welding, the ends of the first insulating resin layers melt and weld. The material melts and accumulates in this groove, and the first insulating resin layer and the welding material are fused, and the first insulating resin layer is reliably welded.

On the other hand, a considerable portion of the conductive resin layer on the end side is removed, and the end thereof is set back a considerable distance from the end of the first insulating resin layer, so that the first insulating resin layer In the process of welding the resin layer, the ends of the conductive resin layer do not melt and mix into the weld bead of the first insulating resin layer. Furthermore, since the ends of the conductive resin layer are set back, it is possible to carry out processing such as cutting to flatten the surface of the weld bead produced by welding the first insulating resin layer.

[0013] Also, a considerable portion of the end of the second insulating resin layer has been removed, and the end has retreated a considerable distance from the end of the conductive resin layer, so that welding of the conductive resin layer is difficult. In the process, the end portion of the second insulating resin layer does not melt and mix into the weld bead of the conductive resin layer. In addition, since the ends of the conductive resin layer and the second insulating resin layer are removed and the groove portion is wide, the weld bead of the conductive resin layer can be removed after welding the conductive resin layer. It becomes possible to perform processing such as cutting to make it flat. Then, after treating the weld bead generated by welding the conductive resin layer to make its surface substantially flat, the second insulating resin layer is welded using an insulating resin welding material. The weld bead of the conductive resin layer is reliably prevented from being mixed into the weld bead of the insulating resin layer.

In the welding of the first insulating resin layers, a welding rod having a substantially flat surface portion of the first insulating resin layer that will become the weld bead is used to weld the first insulating resin layers together. When welding, the surface of the weld bead of the first insulating resin layer is substantially flat, and mixing of the weld bead and the weld bead of the conductive resin layer is reliably prevented.

[0015] Furthermore, in a method comprising a step of treating a weld bead generated by welding the first insulating resin layers to make the surface of the weld bead substantially flat, the weld bead and the conductive resin layer mixing with the weld bead is more reliably prevented.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a groove structure according to a welding method for laminated resin materials according to an embodiment of the present invention, and FIG. 2 is a plan view thereof. In this embodiment, the same laminated resin material 4 as that used in the conventional example described above is used as the laminated resin material 4, and a description of its structure will be omitted. Two laminated resin materials 4 to be welded as shown in the figure,
4 are disposed at positions where the end portions are close to each other and face each other, and the end portions 10, 4 of the first insulating resin layer 1 are opposite to each other.
10 is cut diagonally, and the mutually opposing ends are processed to form a substantially V-shaped groove 6a. Although the grooves 6a can have other shapes, if they are formed into a substantially V-shape, the molten welding material tends to accumulate along the grooves 6a, improving the reliability of welding. A considerable portion of the conductive resin layer 2 on the end side is removed, and the end 20 is set back by a considerable distance from the end 10 of the first insulating resin layer 1, and the first insulating resin layer 1 is exposed a considerable distance from its end 10. Further, a considerable portion of the end portion of the second insulating resin layer 3 is also removed, and the end portion 30 is set back a considerable distance from the end portion 20 of the conductive resin layer 2.
The upper surface of is exposed a considerable distance from the end 20 thereof.

After the groove is formed into the structure described above, the laminated resin materials 4, 4 are welded. First, the first insulating resin layers 1, 1 are welded using an insulating resin (vinyl chloride resin) welding rod (welding material). In this case, as a welding rod,
As shown in FIG. 3, a welding rod 1 in which a portion 11a of the first insulating resin layer, which becomes the surface of the weld bead, is formed substantially flat.
Welding is performed using 1. As a result, the first surface has a substantially flat surface.
A weld bead 1a of the insulating resin layer 1 is formed. In this welding process of the first insulating resin layers 1, 1, since the end 20 of the conductive resin layer 2 is set back by a considerable distance from the end 10 of the first insulating resin layer, the first In the process of welding the insulating resin layer 1, the end portion 20 of the conductive resin layer 2 will not melt and mix into the weld bead 1a of the first insulating resin layer 1.

Next, the conductive resin layers 2, 2 are welded using a conductive resin welding rod (not shown) in which carbon powder is dispersed in vinyl chloride resin. At this time, since the surface of the weld bead 1a of the first insulating resin layer 1 is substantially flat, the welding process of the conductive resin layer 2 can be performed easily and reliably, and the bead 1a has a conductive surface. Mixing of the weld bead 2a of the resin layer 2 is effectively prevented. Also,
Also in the process of welding the conductive resin layer 2, since the end 30 of the second insulating resin layer 3 is set back by a considerable distance from the end 20 of the conductive resin layer 2, the welding of the conductive resin layer 2 is difficult. During the process, the end portion 30 of the second insulating resin layer 3 will not melt and mix into the weld bead 2a of the conductive resin layer 2.

After welding the conductive resin layer 2 in this manner, the surface of the weld bead 2a is scraped to form the conductive resin layer 2.
The surface of the weld bead 2a is flattened so that the surface of the weld bead 2a is substantially flush with the surface of the weld bead 2a.

Then, the second insulating resin layers 3, 3 are welded using an insulating resin welding rod. At this time, since the surface of the weld bead 2a of the conductive resin layer 2 is treated flat and has no large irregularities, the welding process of the second insulating resin layer 3 is facilitated, and reliable welding can be performed. At the same time, the weld bead 2a of the conductive resin layer 2 is prevented from being mixed into the weld bead 3a of the second insulating resin layer 3.

[0021] By welding the second insulating resin layer 3 in this manner, the welding process of the laminated resin material 4 is completed, and the laminated resin materials 4, 4 are reliably bonded.

As described above, according to the method of welding laminated resin materials of the present invention, the movable surfaces (for example, liquid contact surfaces) and the conductive surfaces of the first insulating resin layer 1 and the second insulating resin layer 3 Insulation between the resin layer 2 and the resin layer 2 can be ensured. The welding method of the present invention is applied, for example, to manufacturing a structure equipped with a corrosion resistance deterioration detection system as shown in FIG. Fifth
In the corrosion resistance deterioration detection system A shown in the figure, an electrode 52 is provided inside a tank 51 formed by lining the inner surface of a metal material 50 with a laminated resin material 4. It is connected to a metal terminal 53 embedded in the conductive resin layer 2 from the insulating resin layer 1 side (that is, the outside of the tank 51), and a power source 54 and a detector 55 are connected between the electrode 52 and the metal terminal 53. It has been inserted. In the corrosion resistance deterioration detection system A configured in this way, for example, a crack 57 is generated in the second insulating resin layer 3 on the inner surface side of the tank 51, and from this crack 57, the conductive resin layer 2 is exposed to the inside of the tank. The second insulating resin layer is detected by the detector 55 detecting continuity between the liquid contact side of the first insulating resin layer 3 and the conductive resin layer 2, which is caused by the penetration of the liquid 58. Cracks in (corrosion resistant resin layer) 3 5
Deterioration of the corrosion resistance of the structure (tank 51) due to occurrence of No. 7 is electrically detected.

In the corrosion resistance deterioration detection system A described above, the laminated resin material 4 is welded by the welding method of the present invention, and the second insulating resin layer 3 (wetted resin layer) is electrically conductive with the inner surface of the tank. Since the corrosion-resistant resin layer 2 is reliably insulated, the corrosion resistance deterioration detection system A operates reliably and its reliability is improved.

In the above embodiment, the weld bead 1a of the first insulating resin layer 1 is used for welding the first insulating resin layer 1.
A welding rod 1 having a substantially flat surface portion 11a.
1 is used, but a normal round welding rod may also be used. In addition, after welding using a round welding rod, etc., the surface of the weld bead that is generated is processed to make it flat by cutting, etc. to make it easier to weld the next layer, the conductive resin layer. Mixing of the weld bead of the first insulating resin layer and the weld bead of the conductive resin layer may be more reliably prevented.

In the above embodiment, the insulating resin layers 1 and 3 constituting the laminated resin material 4 are made of vinyl chloride resin, and the conductive resin layer 2 is made of vinyl chloride resin mixed with carbon powder. However, the material of each layer is not limited to the above examples; other resin materials can be used, and metal powder, conductive resin powder, etc. can also be used instead of carbon powder. be. Furthermore, the first and second insulating resin layers may be made of the same material, or may be made of different materials.

Although the end faces of the conductive resin layer and the second insulating resin layer are cut vertically in the above example, they are cut diagonally at an appropriate angle, so that the structure of the entire groove is
It may be formed in a V-shape having a stepped portion (that is, a recessed portion of the conductive resin layer and the second insulating resin layer).

[0027]

As described above, according to the method for welding laminated resin materials of the present invention, the ends of the first insulating resin layer are opposed to each other to form a groove, and the ends of the conductive resin layer are The groove is set back a considerable distance from the end of the first insulating resin layer, and the end of the second insulating resin layer is set back a considerable distance from the end of the conductive resin layer. At the same time, the second insulating resin layer is welded after the weld bead of the conductive resin layer is treated so that its surface becomes substantially flat, so the weld bead of the conductive resin layer is formed in the welding process. is prevented from entering the weld bead of the first and second insulating resin layers, and the operating surfaces (for example, wetted surfaces) of the first and second insulating resin layers and the conductive resin Insulation between the layers can be maintained reliably.

Furthermore, a method of welding the first insulating resin layer using a welding rod in which the surface of the weld bead of the first insulating resin layer is formed substantially flat, and a method of welding a round rod shape. In the method of welding the conductive resin layer, which is the next layer, by welding with a rod, etc., and then flattening the surface of the weld bead by cutting, etc., the conductive resin layer can be welded more reliably. At the same time, mixing of the weld bead of the first insulating resin layer and the weld bead of the conductive resin layer can be more reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a groove structure obtained by a welding method according to an embodiment of the present invention.

FIG. 2 is a plan view showing a groove structure obtained by a welding method according to an embodiment of the present invention.

FIG. 3 is a perspective view showing a welding rod used in the embodiment of FIGS. 1 and 2. FIG.

FIG. 4 is a front view showing a state in which laminated resin materials are welded by the welding method of the present invention.

FIG. 5 is a diagram illustrating a system A for detecting corrosion resistance deterioration of a structure manufactured using the welding method of the present invention.

FIG. 6 is a front view showing a groove structure in a conventional welding method.

FIG. 7 is a front view showing a state in which laminated resin materials are welded by a conventional welding method.

[Explanation of symbols]

Claims (3)

[Claims] [Claim 1] A conductive resin layer is applied from both sides to the first and second conductive resin layers.
In the method of welding together laminated resin materials sandwiched by insulating resin layers, the first layer of the laminated resin materials to be welded together
Grooves are formed facing each other at positions where the ends of the insulating resin layer are close to each other, and a considerable portion of the end portion of the conductive resin layer is removed, and the end portion is connected to the first insulating resin layer. A considerable distance is set back from the end of the second insulating resin layer, and a considerable portion of the end of the second insulating resin layer is removed, and the end is set back a considerable distance from the end of the conductive resin layer. a groove forming step of forming a groove in the structure, welding the first insulating resin layers together using an insulating resin welding material, and then
The conductive resin layers are welded together using a conductive resin welding material, and the weld bead generated by welding the conductive resin layers is treated to make the surface approximately flat, and then the insulating resin welding material is welded. 1. A welding method for laminated resin materials, the method comprising: welding the second insulating resin layers together using a welding method. 2. In the step of welding the first insulating resin layer, a portion of the insulating resin welding material that will become the surface of the weld bead of the first insulating resin layer is formed substantially flat. 2. The method of welding a laminated resin material according to claim 1, wherein the first insulating resin layer is welded using a rod to make the surface of the weld bead substantially flat. 3. The step of welding the first insulating resin layers further comprises the step of treating a weld bead generated by welding the first insulating resin layers to make the surface substantially flat. 2. The method of welding laminated resin materials according to claim 1.