JP6087656B2 - Pinhole detection method for water shielding sheet - Google Patents

Description

  The present invention relates to a pinhole detection method for a water shielding sheet laid in a waste disposal site.

  Pinholes may occur in the water shielding sheet laid at the waste disposal site when laying the site. For this reason, the presence or absence of a pinhole was inspected after laying the site, and if there was a pinhole, that portion was repaired.

Japanese Patent No. 3,710,840 proposes the construction of the following water shielding sheet as a structure of the water shielding sheet suitable for this pinhole detection.
In the final disposal site for waste, an electrically conductive sheet 2 (for example, an electrically conductive nonwoven fabric) and a water shielding sheet 1 (for example, a vulcanized rubber sheet, a polyethylene sheet) are sequentially laid separately on these substrates. It is a structure which ensures electroconductivity through a conductive adhesive double-sided tape etc. between two. Then, by moving the inspection electrode brush 7 on the water-impervious sheet 1, the energized state between both sheets is electrically detected to detect the presence or absence of the pinhole 5 in the water-impervious sheet. (See Figures 1-3)
That is, the conductive sheet 2 and the water shielding sheet 1 are separately laid without being integrated, and the conductive property between the two is secured by a conductive means such as a conductive adhesive double-sided tape.

Japanese Patent No. 3710840

However, in this water shielding sheet laying structure, it is difficult to accurately detect a pinhole unless a good energization state is maintained between the conductive sheet and the water shielding sheet. For example, if there is a gap in which air or the like is interposed between the conductive sheet and the water shielding sheet, it is difficult to energize even if there is a pinhole in the water shielding sheet. Therefore, the alarm buzzer and the alarm lamp may not work.
Therefore, it is necessary to join the electrically conductive sheet and the water shielding sheet on the site locally or over a relatively wide range using a conductive adhesive double-sided tape or a conductive adhesive to eliminate a gap. This joining work requires a lot of construction time and cost.

  The object of the present invention is to eliminate the bonding between the electrically conductive sheet and the water shielding sheet, and even if the water shielding sheet floats and there is a gap between these sheets, the current is accurately passed between the two sheets to pinhole. Provides a method by which can be detected.

Means and effects for solving the problems

The pinhole detection method of the first aspect of the present invention is a pinhole detection method for a water shielding sheet laid in a waste disposal site,
A step of laying an electroconductive mat on the base of the water-impervious sheet, a step of laying a water-impervious sheet on the electroconductive mat, a sheet pressing member disposed on the water-impervious sheet, A step of pressing against the conductive mat, and a step of detecting a pinhole by disposing an electrode brush on the pressed water shielding sheet,
In the pressing step, the sheet pressing member presses a portion where the water shielding sheet is lifted, and the water shielding sheet and the conductive mat are brought into close contact with each other.
The detection step by the electrode brush is performed immediately after the pressing step by the sheet pressing member, and the electrode brush is caused to act along the close contact portion in the pressing step ,
Assembly and a said sheet holding member and the electrode brush has an operating portion of the handle structure, the operating portion is operated by human power, Rukoto reacted with pressing the whole of the necessary portions of the water shield sheet It is characterized by.

According to the configuration of the present invention, the water-impervious sheet and the conductive mat are brought into close contact with each other by pressing by the sheet pressing member on the water-impervious sheet, and energization between the two members is ensured. Immediately after this pressing, that is, in a state where energization between both members is ensured, the electrode brush detects a pinhole in the water shielding sheet. A pinhole can be detected in a state where energization between both members is ensured over a wide range by scanning and moving on the water shielding sheet with the sheet pressing member and the electrode brush set.
In addition, since there is no current-carrying member such as a conductive adhesive double-sided tape between the conductive mat and the water-impervious sheet, the laying operation of the water-impervious sheet can be easily performed.

  In the pinhole detection method according to a second aspect of the present invention, in the first aspect of the invention, the pressing step is performed while the rotatable sheet pressing member is rotated on the water shielding sheet.

  According to this configuration, by rotating and rotating the rotatable sheet pressing member on the water shielding sheet, the water shielding sheet can be pressed against the conductive mat over a wide range with a simple configuration.

  The pinhole detection method of the third aspect of the present invention is the method according to the second aspect, wherein the sheet pressing member is attached to the electrode brush so as to precede the electrode brush.

  According to this configuration, the rotatable sheet pressing member and the electrode brush can be set and scanned on the water shielding sheet.

In the pinhole detection method according to a fourth aspect of the present invention, in the second or third aspect, the sheet pressing member applies a pressure of 1 to ²⁰ N / cm ² to the water shielding sheet. Preferably, a pressure of 5 to 15 N / cm ² is applied to the water shielding sheet.

According to this configuration, both members can be properly brought into close contact with each other. That is, when the pressure is less than 1 N / cm ² , the pressure is too small and the water shielding sheet and the conductive mat may not be in close contact with each other. On the other hand, when the pressure exceeds 20 N / cm ² , the pinhole of the water shielding sheet is also deformed and accurate inspection cannot be performed, and the sheet pressing member and the electrode brush are set to scan and move on the water shielding sheet. The work load becomes worse and workability becomes worse.

It is a figure which shows the outline | summary of laying structure, an inspection apparatus, and a detection method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating an outline of a laying structure, an inspection apparatus, and a detection method. Hereinafter, the laying structure, the inspection apparatus, and the detection method will be described in order.

[Laying structure]
As shown in FIG. 1, the laying structure 1 includes an electrically conductive mat 4 laid on a base 3 of a water shielding sheet 2 and a water shielding sheet 2 laid separately on the conductive mat 4. It consists of.

The conductive mat 4 is an underlay having electrical conductivity. For example, a conductive fabric using a woven fabric or nonwoven fabric affixed to the surface of an aluminum foil, a conductive nonwoven fabric containing fibers mixed with carbon, or a fiber formed by chemically forming polypyrrole, an electron-conjugated conductive polymer. The nonwoven fabric is selected from conductive nonwoven fabrics using fibers produced by treating acrylic fibers with a compound containing a divalent copper compound and sulfur. The thickness is preferably 1.0 to 20.0 mm for not only the conductivity but also the reinforcing function as an underlay.
Normally, the conductive mat 4 is laid on the entire surface of the base 3 of the water shielding sheet 2. However, the conductive mat 4 can be partially laid when the part where the pinhole is generated is determined.

  Examples of the water shielding sheet 2 include resin materials such as thermoplastic elastomer, polyethylene, polypropylene, and polyvinyl chloride, EPDM (ethylene propylene diene monomer), IIR (butyl rubber), NR (natural rubber), SBR (styrene / styrene). Examples thereof include waterproof sheets made of rubber materials such as butadiene rubber, CR (chloroprene rubber), NBR (acrylonitrile butadiene rubber), HNBR (hydrogenated acrylonitrile butadiene rubber), and CSM (chlorosulfonated polyethylene). Of these, resin materials such as thermoplastic elastomers, polyethylene, polypropylene, and polyvinyl chloride that are close to insulating are preferable. When a large amount of carbon black is contained, the electrical conductivity is enhanced, and even when there is no pinhole, the current is normally supplied, and it is difficult to accurately detect the pinhole. (It is necessary to energize in the part where the pinhole exists.) In addition, a small amount of carbon black or the like is contained in the sheet of these materials in order to enhance the reinforcement, but in some cases, glass fiber, polyester fiber, etc. It is also possible to improve the mechanical strength or improve the dimensional stability by embedding a reinforcing cloth made of The thickness is preferably in the range of 0.5 to 3.0 mm.

[Inspection equipment]
Next, an outline of the inspection apparatus 10 will be described with reference to FIG.

  The inspection device 10 includes an electrode brush assembly 11, a sheet pressing member 12, and a pinhole inspection machine 13.

  The electrode brush assembly 11 includes a rectangular box 21, an electrode brush 22 planted downward from the lower surface thereof, and an operation unit 23 erected obliquely upward from the upper surface of the box 21.

  The rectangular box 21 has a width of 0.5 to 1.5 m, usually about 1 m. A brass electrode brush 22 is planted downward over the entire length of the width. If the width of the box 21 is too long, it is difficult to operate. On the other hand, if it is too short, efficient inspection cannot be performed. The electrode brush 22 extends below the rotary body 25 described below, that is, near the lower contact of the rotary body 25.

  The operation unit 23 is provided for manual scanning movement or automatic scanning movement. In the illustrated example, a handle structure suitable for manual scanning movement is shown. In the case of automatic scanning movement, a connection structure to the traction rope may be used.

  The sheet pressing member 12 is configured such that an arm 26 that rotatably supports the rotating body 25 can be mounted on the side surface of the box 21. If the box 21 can be mounted, the rotating body 25 can be easily replaced. When the rotating body 25 is replaced, the pressure of the pressing described below can be changed to an appropriate one.

  The rotating body 25 is configured by rotatably mounting one roller or a plurality of wheels on a rotating shaft. In order to keep the pressing pressure described below appropriately, it is preferable to use a rotating body 25 having a diameter of 50 to 200 mm. Moreover, the weight can be adjusted by injecting an appropriate amount of liquid into a roller or a wheel.

Such a sheet pressing member 12 usually has a load that applies a pressure of 1 to ²⁰ N / cm ^2, preferably 5 to 15 N / cm 2 to the water-impervious sheet 2 to bring the two members into close contact with each other. If the pressure is less than 1 N / cm ² , the water shielding sheet 2 and the conductive mat 4 may not be in close contact with each other. On the other hand, if the pressure exceeds 20 N / cm ² , the pinhole of the water shielding sheet 2 is also deformed. Therefore, accurate inspection cannot be performed, and a load is imposed on the work of scanning and moving on the water-impervious sheet with the sheet pressing member and the electrode brush set, resulting in poor workability.

Such a sheet pressing member 12 is provided in front of the traveling direction of the electrode brush assembly 11. Therefore, when the electrode brush assembly 11 is scanned and moved, the sheet pressing member 12 precedes and appropriately presses the water shielding sheet 2.
As described above, the sheet pressing member 12 includes the rotating body 25 such as a rotatable wheel, the arm 26 of the rotating shaft is mounted on the box body 21, and the water shielding sheet 2 is attached to the conductive mat 4. It has a function of pressing and closely contacting.

  After connecting the cathode 27 of the pinhole inspection machine 13 to the conductive mat 4 on the lower side of the water shielding sheet 2, the inspection apparatus 10 is set to an applied voltage of 5 to 25 KV and is made of brass wire with the sheet pressing member 12 attached. The electrode brush 22 is manually scanned or automatically scanned along the surface of the water shielding sheet 2 to detect whether or not discharge (spark) has occurred. If there is no discharge, there is no pinhole and the product is accepted.

  The pinhole inspection machine 13 generates a high voltage on a brass electrode brush 22 having a width of about 1 m connected via a high voltage cord 28 and detects the occurrence of discharge in the vicinity of the electrode brush 22 by a lamp or a buzzer. A function can also be provided.

  When there is no pinhole in the impermeable sheet 2, it is insulated by the impermeable sheet 2 and does not discharge. On the other hand, if a pinhole is generated in the water shielding sheet 2, a discharge occurs in the conductive mat 4 from the upper surface of the water shielding sheet 2 through the pinhole. Pinholes can be detected by detecting this discharge.

  When the applied voltage exceeds 20 kV, it becomes dangerous. On the other hand, when the applied voltage is less than 5 kV, the discharge cannot be generated. Therefore, the applied voltage capable of detecting the pinhole is preferably 5 kV to 20 kV.

  Next, a detection method performed on the above-described laying structure 1 using the above-described inspection apparatus 10 will be described.

<First step>
In FIG. 1, the first step is a step of laying the conductive mat 4 on the base 3 on which the water shielding sheet 2 is scheduled to be laid. The conductive mat 4 is a sheet having a predetermined width, and these are placed so as to be arranged side by side. In order to ensure mutual conductivity, the ends in the width direction are overlapped or joined with a conductive tape.
Usually, the conductive mat 4 is laid on the entire surface of the base 3. When a place where pinholes are likely to occur is determined, the conductive mat 4 can be laid only in that portion.

<Second step>
In FIG. 1, the second step is a step of laying the water shielding sheet 2 on the conductive mat 4 laid on the base 3 so as to cover the entire surface of the base 3. This water-impervious sheet 2 is also a sheet having a predetermined width, and is laid with overlapping ends in the width direction. The overlap portion is bonded by heat fusion or the like so that water can be shielded over the entire surface.
When laying the water shielding sheet 2, no adhesive or the like is interposed between the conductive mat 4. Therefore, as shown in FIG. 1, a portion where the water shielding sheet 2 does not adhere to the conductive mat 4 may be formed.

<Third step>
In FIG. 1, the third step is a step in which the sheet pressing member 12 is disposed on the water shielding sheet 2 and pressed against the conductive mat 4. By selecting the diameter and weight of the rotating body 25 of the sheet pressing member 12, a pressure of 1 to ²⁰ N / cm ^2, preferably 5 to 15 N / cm ² is applied to the water shielding sheet 2. Then, as shown in FIG. 1, immediately below the sheet pressing member 12, the water-impervious sheet 2 and the conductive mat 4 are in close contact with each other, and energization between the two members is ensured.
By pressing the operation unit 23 by human power, the rotating body 25 of the sheet pressing member 12 is rolled, and the scanning movement is performed in the vertical and horizontal directions, the pressing can be applied to the entire necessary portion of the water shielding sheet 2.

<4th process>
In FIG. 1, the 4th process is a process of arrange | positioning the electrode brush 22 with respect to the pressed water-impervious sheet 2, and detecting a pinhole. This fourth step is performed immediately after the third step. That is, the presence or absence of a pinhole can be reliably inspected by placing the electrode brush 22 along a portion where the water-impervious sheet 2 and the conductive mat 4 are in close contact with each other and the conduction between the two members is ensured.
As shown in FIG. 1, the sheet pressing member 12 is attached to the electrode brush assembly 11. Therefore, when the operation unit 23 is operated and the electrode brush 22 is scanned and moved on the water-impervious sheet 2, an appropriate pressing by the sheet pressing member 12 is automatically performed prior to the electrode brush 22.

  Next, the advantages of the detection method described above will be described. First, the first step of laying the conductive mat 4 and the second step of laying the water shielding sheet 2 are sequentially performed independently. Since there is no step of interposing a member for ensuring electrical conductivity between the electrically conductive mat 4 and the water shielding sheet 2, the laying operation of the water shielding sheet 2 can be easily performed.

  Since the sheet pressing member 12 is disposed on the water shielding sheet 2 and presses the water shielding sheet 2 against the conductive mat 4, even if there is a part where the water shielding sheet 2 is lifted, the sheet pressing member 12 It can be pressed with great pressure. For this reason, the water-impervious sheet 2 and the conductive mat 4 are in close contact with each other, and energization between both members is ensured. Since the electrode brush 22 is made to act along this pressing part, a pinhole can be detected reliably.

  Immediately after the third step of pressing the water-impervious sheet 2 against the conductive mat 4, the fourth step of bringing the electrode brush 22 along the pressed water-impervious sheet 4 is performed. Therefore, pinholes are detected and the operability is good with a single operation of manually moving or automatically moving the electrode brush assembly 11 to which the sheet pressing member 12 is mounted.

  Although the preferred embodiments of the present invention have been described above, the above embodiments can be implemented with the following modifications.

  That is, in the above embodiment, the sheet pressing member 12 is not limited to the one using the rotating body 25, and the pressing pad may be slid on the water shielding sheet 2. In this case, the pressing surface of the pressing pad is made of a material that easily slides on the water shielding sheet 2.

  Further, two electrode brush assemblies 11 may be provided before and after the sheet pressing member 12. The scanning movement can be performed only by moving in the reverse direction without changing the direction at the end of the scanning movement. In this case, the electrode brush assembly 11 to be operated may be switched when moving in the reverse direction.

  Further, two sheet pressing members 12 may be provided before and after the electrode brush assembly 11. The scanning movement can be performed only by moving in the reverse direction without changing the direction at the end of the scanning movement. In this case, the sheet pressing member 12 following the electrode brush assembly 11 can have a function of holding the pressing state by the preceding sheet pressing member 12.

DESCRIPTION OF SYMBOLS 1 Laying structure 2 Water shielding sheet 3 Base 4 Conductive mat 10 Inspection apparatus 11 Electrode brush assembly 12 Sheet pressing member 13 Pinhole inspection machine 21 Box body 22 Electrode brush 23 Operation part 25 Rotating body 26 Arm 27 Cathode 28 High voltage cord

Claims (4)

A pinhole detection method for a water shielding sheet laid in a waste disposal site,
Laying a conductive mat on the base of the water shielding sheet;
Laying a water shielding sheet on the conductive mat;
Arranging a sheet pressing member on the water-impervious sheet and pressing the conductive mat;
Arranging an electrode brush on the pressed water shielding sheet and detecting a pinhole,
In the pressing step, the sheet pressing member presses a portion where the water shielding sheet is lifted, and the water shielding sheet and the conductive mat are brought into close contact with each other.
The detection step by the electrode brush is performed immediately after the pressing step by the sheet pressing member, and the electrode brush is caused to act along the close contact portion in the pressing step ,
The assembly including the electrode brush and the sheet pressing member has an operation part having a handle structure, and operates the operation part manually to apply pressure to the entire necessary portion of the water shielding sheet. A pinhole detection method for a water shielding sheet that is characterized. It is a pinhole detection method of the impermeable sheet according to claim 1,
The method of detecting a pinhole in a water shielding sheet, wherein the pressing step is performed while the rotatable sheet pressing member is rotated on the water shielding sheet. The pinhole detection method for a water shielding sheet according to claim 2, wherein the sheet pressing member is attached to the electrode brush so as to precede the electrode brush. The pinhole detection method for a water shielding sheet according to claim 2 or 3, wherein the sheet pressing member applies a pressure of 1 to ²⁰ N / cm ² to the water shielding sheet. Method.

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