JP2002224637A - Method for laying protection sheet for water barrier sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for laying a protection sheet which can protects a water barrier sheet surely over a long period of time. SOLUTION: Such a plurality of long length protection sheets 1 is stuck onto the water barrier sheet 5 successively as is formed by laminating a polyester-made nonwoven fabric layer 2 and a foamed cross-linked polyethylene sheet layer 3 and has a tacky adhesive 4 applied to the whole surface of the layer 3 side. At the position that the adjacent sheets 1 are joined with each other one side edge part of one of the adjacent sheets 1 is folded back to the layer 3 side and adhered to the sheet 1 itself and the folded layer 2a and the layer 2 of the other of the adjacent sheets 1 are welded together thermally by using a handy dry drier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laying a protective sheet used to prevent breakage of a water-impervious sheet installed at the bottom of a landfill site.

[0002]

2. Description of the Related Art In a landfill-type waste disposal site for dumping industrial waste and general waste, the bottom of the disposal site is disposed in order to prevent environmental pollution due to the infiltration of wastewater leaking from the waste into the underground. It is obliged to provide waterproofing work for As such water-blocking work, a method of laying a water-blocking sheet made of soft synthetic resin or rubber is employed.

[0003] However, if a sharp substance in waste is pierced into the water-impervious sheet or a heavy substance is dumped from a high position, the water-impervious sheet is damaged, and sewage leaks therefrom. Would. Therefore, in order to protect the water-impervious sheet, a long-sized protective sheet formed by laminating a nonwoven fabric having excellent piercing resistance and a sheet having a high impact absorption capacity is formed as shown in FIGS. A technique has been proposed in which the edges are overlapped by about 10 cm, laid on the water-impervious sheet 15, and the overlapped portion is heat-sealed to lay the protective sheet 11.

[0004]

However, if the protective sheet 11 is laid as described above, at the joint portion 11a between the adjacent protective sheets, the nonwoven fabric 12 of one protective sheet and the resin of the other protective sheet adjacent to each other can be obtained. Sheet 13
However, since the non-woven fabric 12 and the resin sheet 13 have different coefficients of thermal expansion, the joint portion 11a may peel off during long-term use, and the water-blocking sheet 15 may be damaged therefrom. . In view of the above problems, an object of the present invention is to provide a method for laying a protective sheet that reliably protects a waterproof sheet over a long period of time.

[0005]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 lays on a water-impervious sheet to protect a water-impervious sheet constructed at the bottom of a landfill site. A method for laying at least a first layer made of a thermoplastic synthetic resin and a second layer made of a synthetic resin, wherein the plurality of long protective sheets are laid. At the joint portion between adjacent protective sheets at the time, the side edge of one protective sheet is folded back to the second layer side and adhered to itself, and the folded portion of the first layer and other adjacent protective sheets It is characterized in that the first layer of the sheet is heat-sealed.

According to a second aspect of the present invention, in the first aspect of the present invention, the method of bonding the folded portion includes applying an adhesive to at least one side edge of the second layer side surface of the protective sheet. The adhesive is characterized in that the side edges are turned back and the pressure-sensitive adhesives are brought into close contact with each other to bond them.

According to a third aspect of the present invention, in the first or second aspect, the first layer is a non-woven fabric made of a polyester resin, and the second layer is a sheet made of a polyolefin resin. It is characterized by.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of a protective sheet for a water-impervious sheet according to the present invention (hereinafter simply referred to as a protective sheet). The protective sheet 1 is formed by laminating a nonwoven fabric layer 2 made of polyester and a foamed crosslinked polyethylene sheet layer 3, an adhesive 4 is applied to the entire surface of the foamed crosslinked polyethylene sheet layer 3, and is 2 m long and 10 m long. It is formed in a shape. The nonwoven fabric layer 2 is excellent in piercing resistance and protects the water-blocking sheet 5 from sharp substances,
It plays a role in preventing deterioration due to ultraviolet rays. In addition, the foamed crosslinked polyethylene sheet layer 3 has an excellent shock absorbing ability, and plays a role of alleviating the shock when a heavy substance is dumped from a high position.

Next, a method of laying the protective sheet 1 will be described with reference to FIGS. FIG. 2 is a perspective view showing how the protection sheets 1, 1... Here, in order to distinguish the plurality of protection sheets 1, 1,..., The protection sheets are denoted by reference numerals such as A1, A2, and the like.
FIG. 3 is a side view of the joint portion of the protective sheet 1 as viewed from the direction of arrow A in FIG. FIG. 4 is a schematic diagram showing a state in which the protection sheet 1 is laid by the laying method according to the present invention on the entire surface of the water-blocking sheet 5 installed at the bottom of the disposal site.

First, the protection sheet A1 is attached along the edge of the water-blocking sheet 5. Next, the protective sheet A2 is attached to the water-blocking sheet 5 such that one side edge of the protective sheet A1 overlaps the protective sheet A1 with a width of 10 cm, and the overlapped side edge 5 cm is formed on the foamed crosslinked polyethylene sheet layer 3 side. The nonwoven fabric layer 2 is folded back after the adhesives 4 are adhered to each other, and then folded back.
a is superimposed on the side edge of the nonwoven fabric layer 2 of the protective sheet A1, and they are heat-sealed using a handyster (not shown) (FIG. 3). Similarly, protective sheets A3, A4 ...
Are sequentially laid, and finally, as shown in FIG. 4, the protection sheet 1 is laid on the entire surface of the impermeable sheet 5.

According to the method of laying the protective sheet 1,
The nonwoven fabric layers 2 are joined to each other by folding back the side edges of one of the protective sheets 1 at the joining portion of the adjacent protective sheets 1, so that the nonwoven fabric layers 2 can be firmly heat-sealed. No delamination due to the difference in rate occurs. Further, since the adhesive 4 is applied to the protective sheet 1, the folded side edge can be easily adhered to itself during the laying operation, and after the construction, the protective sheet 1 is acted on by the action of the adhesive 4. Does not shift with respect to the impermeable sheet 5. Further, the protective sheet 1 includes a nonwoven fabric layer 2
Since polyester is used as the material, the water-blocking sheet 5 can be effectively protected from sharp substances in waste, and deterioration due to ultraviolet rays can be prevented. On the other hand, since the foamed cross-linked polyethylene is used as the material of the sheet layer 3, the impact when a heavy substance is dumped can be reduced.

The protective sheet for a water-impervious sheet of the present invention is not limited to the above-described embodiment, but includes the structure and shape of the protective sheet, the first layer, the second layer, the adhesive and the like. It can be changed as appropriate without departing from the scope. For example, a sheet in which the first layer is formed of a thermoplastic synthetic resin can be used. However, a nonwoven fabric is preferable because the piercing resistance is high, and a piercing resistance is particularly preferable if the nonwoven fabric is made of a polyester resin. This is preferable because it is extremely high and has an effect of preventing deterioration due to ultraviolet rays.
When the first layer is a nonwoven fabric, its thickness is not particularly limited, but it is preferable that the thickness be 5 mm or more, because the piercing resistance is dramatically improved. Furthermore, JIS-L-10
It is particularly preferable to use a nonwoven fabric having a tear strength in the longitudinal direction and width direction of 20 kgf / cm or more according to the test method of No. 85, since the protective sheet becomes very hard to break and the water-impermeable sheet can be effectively protected. . It is also recommended to coat the first layer with a film such as a felt mat which protects the sheet from rain, snow and ultraviolet rays.

As the second layer, a normal polyolefin resin sheet or an EVA or rubber sheet can be suitably used. If a polyethylene sheet having a cellular structure is used, the protective sheet itself can be used. Is preferable because it has excellent water barrier properties. When a sheet having a cell structure is adopted, the apparent density is about 0.01 to 0.5.
The use of a highly foamed g / cm ³ foam is preferred in that the weight of the protective sheet is reduced and workability is improved. Further, the thickness of the sheet is not particularly limited, but it is particularly preferable that the thickness be 4 mm or more, because the impact absorbing ability of the sheet is dramatically improved. Note that a foamed sheet made of uncrosslinked polyethylene may be used as the resin sheet.

If the pressure-sensitive adhesive is applied only to one side edge of the protective sheet, the protective sheet is not restrained by the water-impermeable sheet, so that the stress applied to the protective sheet can be dispersed. Regarding the method of heat fusion at the joint between the protective sheets, not only a method using a hand layster but also a method using an extrusion welding machine or the like can be used. The overlap width (turnback width) of the protective sheet is also arbitrary, but is preferably 5 cm or more from the viewpoint of strength.

[0015]

As described in detail above, according to the first aspect of the present invention, the joint between the protective sheets does not peel off,
The impermeable sheet can be reliably protected for a long time.

According to the invention described in claim 2, according to claim 1
In addition to the effect, the efficiency of the work of laying the protective sheet is improved.

According to the third aspect of the present invention, the first aspect is provided.
In addition to the effects of (1) and (2), the waterproof sheet can be effectively protected from sharp substances and impact.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a protection sheet according to the present invention with a part thereof omitted;

FIG. 2 is a perspective view illustrating a method for laying a protective sheet according to an embodiment of the present invention.

FIG. 3 is a side view of the protection sheet as viewed from the direction of arrow A in FIG. 2;

FIG. 4 is a schematic view showing a state in which a protective sheet is laid by the laying method according to the present invention on the entire surface of the impermeable sheet installed on the bottom of the landfill disposal site.

FIG. 5 is a perspective view showing a conventional protection sheet laying method.

FIG. 6 is a side view of the protective sheet as viewed in the direction of arrow B in FIG.

[Explanation of symbols]

1. Protective sheet, 2. Non-woven fabric layer (first layer), 2a
A folded nonwoven fabric layer; a foamed crosslinked polyethylene sheet layer (second layer); a pressure-sensitive adhesive; a water-blocking sheet.

Claims (3)

[Claims] 1. A first layer made of at least a thermoplastic synthetic resin and a second layer made of a synthetic resin, which are laid on the impermeable sheet to protect the impermeable sheet provided at the bottom of the landfill site or the like.
A method for laying a plurality of elongate protective sheets by laminating a plurality of layers of the protective sheet, wherein a side edge of one protective sheet at a joint portion between adjacent protective sheets when the plurality of protective sheets are laid out and arranged. A portion which is folded back to the second layer side and adheres to itself, and the first layer of the folded portion and the first layer of another adjacent protective sheet are heat-sealed. How to lay a sheet protection sheet. 2. A method of bonding the folded portion, wherein an adhesive is applied to at least one side edge of the surface of the protective sheet on the second layer side, and the side edge is folded to bring the adhesives into close contact with each other. The method for laying a protective sheet for a water-impervious sheet according to claim 1, wherein the protective sheet is adhered. 3. The method according to claim 1, wherein the first layer is a nonwoven fabric made of a polyester resin, and the second layer is a sheet made of a polyolefin resin.