JPH06185032A - Impermeable sheet - Google Patents

Abstract

PURPOSE:To prevent an impermeable sheet from being suffered a laceration by a shapened matter by providing impermeable layers to one side or both sides of knitting work as a unit, and setting horizontal and vertical tensile extension or knitting stitches in the specific limits. CONSTITUTION:Knitting work is so knitted that knitting stitches are 50g/m<2> 800g/m<2>. For example, temporarily twisted work threads of polyester fabric are used, they are composed in an organization of three steps and both sides by a knitting machine of 18 gauges, and knitting work having stitches 270g/m<2> is knitted. After that, impermeable layers such as polyvinyl chloride, etc., are provided to one side or both sides of the knitting work as a unit, and horizontal and vertical tensile tension is 50-500%. For example, ethylenepropylene synthetic rubber is vulcanized to both sides with one side only having 0.7mm in thickness and is made to adhere to the knitting work. It is laid on a waste disposal place. According to the constitution, an impermeable sheet can be laid even on an uneven laying surface and land subsidence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof sheet, and more particularly to a waterproof sheet for general civil engineering / construction and marine civil engineering / construction.

[0002]

2. Description of the Related Art Polyvinyl chloride sheets and rubber sheets, which are typical products of water-impervious sheets, have a tensile elongation of 200 to 600%. It has the advantage of fitting on the laying surface. However, if there are sharp-edged objects such as rocks and rubbles on the laying surface, stress concentrates on the portions of the sharp-edged objects that come into contact with the tips of the sharp-edged materials, causing tearing of the water-permeable sheet i. In addition, when dumping heavy objects such as earth and sand on the impermeable sheet, such as in a waste disposal site, the ground will sink due to the heavy objects and tensile stress will be applied to the impermeable sheet. It is necessary to have a tensile elongation that can withstand the stress.

[0003] Further, a water-impervious sheet containing a base cloth in which a water-impervious layer and a woven fabric are integrated has been developed. As a typical example thereof, a woven fabric having a thickness of 2 mm and a polyvinyl chloride layer having a thickness of 1 mm are used as a base fabric. Examples of the water-impermeable sheet having a thickness of 3 mm are those having a tensile strength of 500 kg / 3 cm or more and a tensile elongation of 20% or less.

By the way, the above-mentioned water-impervious sheet of plain woven base cloth can be applied to, for example, landfill sand which cannot be resisted by conventional water-impervious sheets. It counters the earth pressure of the landfill. Therefore, even when using the woven fabric-containing water-impervious sheet having ruggedness and sharp edges, there is an advantage that tearing is unlikely to occur, but the tensile elongation is inferior, and it fits to the uneven surface. There was a problem of lack of sex.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the drawbacks of the conventional water-impervious sheet, does not cause laceration even when it is used for a laying surface having a pointed object, and has an uneven surface. However, it is an object to provide a waterproof sheet having a high fit property.

[0006]

The present invention takes the following means in order to solve such problems. That is, according to the present invention, a water blocking layer is provided on one side or both sides of a knitted fabric to be integrated, and the tensile elongation in the vertical direction and the horizontal direction is 5
It is a waterproof sheet having a range of 0 to 500%.

The present invention will be described in detail below. In the present invention, a knitted fabric is selected as the base fabric. This is to improve the fitting property to the uneven surface by using a knitted fabric having a high elongation, and the knitted fabric is preferably warp knitted fabric such as warp knitted fabric such as tricot knitted fabric and Russell knitted fabric.

The fibers constituting the knitted fabric include recycled fibers such as rayon, semi-synthetic fibers such as acetate, polyamide series, polyester series, polyolefin series, polyvinyl alcohol series, polyvinylidene chloride series, polyvinyl chloride series, polyacrylonitrile. System, polyalkylene paraoxybenzoate system, phenol system, polyfluoroethylene system, and in some cases, cotton,
Fibers such as hemp, wool, and silk can also be used, and it is important to select the type of fiber according to the required strength and elongation.
Needless to say, such fibers are preferably used as monofilament yarns, multifilament yarns, textured yarns such as false twist textured yarns, textured yarns such as spun yarns, and yarns such as spun yarns.

Further, the water-blocking layer must be integrally provided on one side or both sides of the knitted fabric. This is because the water barrier effect is exhibited and the tensile elongation needs to be set to an appropriate value. Examples of the water-impermeable layer include polyvinyl chloride, rubber, and ethylene vinyl acrylate (EVA) which are used to impregnate one side or both sides of the knitted fabric, topping or laminate, or a combination thereof.

The thickness of the water-impervious layer is 0.5 to 3 mm in consideration of tensile elongation, resistance to sharp objects, and the like.
A thickness of ~ 3 mm is preferred.

Further, the water-impermeable sheet in which the water-impermeable layer and the knitted fabric are integrated has an elongation of 50 to 50 in both the vertical and horizontal directions.
It should be in the range of 500%, preferably 80-450%.

[0012]

【Example】

Example 1 A false twisted yarn of polyester fiber (150d / 48f) was used to knit into a three-stage double-sided structure with an 18 gauge knitting machine,
A knitted fabric having a basis weight of 270 g / m ² was knitted. Ethylene propylene synthetic rubber (EPD)
M) was vulcanized on both sides with a thickness of 0.7 mm on one side to obtain a base-containing cloth waterproof sheet having a total thickness of 2 mm. This waterproof sheet was subjected to a tensile test and a tear test described in JIS A 6008 (synthetic molecular roofing), and the results are shown in Table 1. For comparison, an ethylene-propylene synthetic rubber (EPDM) is used to have a thickness of 2 m.
The physical properties of the rubber plate made to be m are also shown.

[0013]

[Table 1]

As is clear from Table 1, in Example 1, the tensile strength was 90 Kg / cm ² or more in both the vertical and horizontal directions, and the tensile elongation was considerably large. The strength and tensile elongation were well balanced, and the tear strength was higher than that of the rubber alone.

[0015]

INDUSTRIAL APPLICABILITY The present invention has the effect of providing a waterproof sheet that does not cause laceration even when laid on a surface having a pointed object and is excellent in fit to uneven surfaces, and is particularly useful for disposal. When used in a waste treatment plant, it has the excellent effect of following uneven laying surfaces and ground subsidence, and preventing leakage even if sewage containing toxic substances from waste is leached out.

Claims (2)

[Claims] 1. A water-impervious layer is provided on one side or both sides of a knitted fabric so as to be integrated, and the tensile elongation in the vertical direction and the horizontal direction is 5
A waterproof sheet having a range of 0 to 500%. 2. The basis weight of the knitted fabric is 50 g / m ^{2 to} 800 g.
The water impervious sheet according to claim 1, which is in the range of / m ² .