JPH07276572A - Water barrier sheet, production thereof and waste accumulation yard - Google Patents

Abstract

PURPOSE:To provide a water barrier sheet excellent in buffering properties, restoration properties, execution properties, drainage properties and degassing properties and adapted to a waste accumulation yard. CONSTITUTION:In a laminated sheet wherein a nonwoven fabric 1 is fused to both surfaces of a thermoplastic resin sheet 1, the m.p. of the polymer constituting the resin sheet 2 is lower than that of the fiber constituting the nonwoven fabric 1 and a composite layer 3 consisting of the fiber constituting the nonwoven fabric 1 and the polymer constituting the thermoplastic resin sheet 2 is formed to the interface of the layer of the nonwoven fabric 1 and the thermoplastic resin sheet 2 and the water transmission coefficient in the in-plane direction of the nonwoven fabric 1 is 1X10cm/sec or more under pressure of 5kg/cm<2>. In a waste accumulation yard constituted of a wall part and a floor part both of which are composed of the ground or a rigid material, this water barrier sheet is stretched over the wall and floor parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof sheet for an industrial waste treatment plant, particularly for buffering the impact of the input of industrial waste or the impact of waste sorting by heavy equipment, and further degassing in the waste site. The present invention relates to a water-blocking sheet capable of promptly guiding permeated water to a collection / drainage channel and a waste accumulation site composed of the same.

[0002]

2. Description of the Related Art Conventionally, as the water shield sheet used in the construction work of an industrial waste treatment plant, a water shield sheet made of a synthetic resin such as synthetic rubber or vinyl chloride, or a material such as rubber asphalt is used. However, there is a concern that these water-impervious sheets may be broken when they collide with or are pressed against the protrusions of waste or rocks. As a method for improving such concern, there is a method of covering the above-mentioned water-blocking sheet with soil, a method of attaching a non-woven fabric having a high cushioning property to the sheet surface with an adhesive, or a method of heat-sealing.

[0003]

However, these methods are disadvantageous in that they are labor-intensive and not stable, and the non-woven fabric is easily peeled off, and the fibers are melted. There was a problem that the characteristics it had were lost.

The present invention is a water-impervious sheet which has the characteristics of conventional water-impervious sheets as it is, and which is excellent in cushioning property, restoring property and workability, and which is excellent in drainage property and deaeration property. It intends to provide a waste accumulation site consisting of it.

[0005]

The present invention employs the following means in order to achieve such an object. That is, the water-blocking sheet of the present invention is a laminated sheet in which a nonwoven fabric is fused on both sides of a thermoplastic resin sheet, and the melting point of the polymer constituting the resin sheet is lower than the melting point of the fibers constituting the nonwoven fabric, In addition, a composite layer composed of the fibers forming the nonwoven fabric and the polymer forming the thermoplastic resin sheet is formed at the interface between the nonwoven fabric layer and the thermoplastic resin sheet, and the in-plane surface of the nonwoven fabric layer is formed. The hydraulic conductivity in the direction is 1 × 10 ⁻³ cm / sec or more under a pressure of 5 kg / cm ² . Further, the method for producing a water-blocking sheet of the present invention is such that a thermoplastic resin having a melting point lower than that of fibers constituting the nonwoven fabric is melted and supplied between a plurality of nonwoven fabric sheets, and these are pressed. It is characterized by that. Furthermore, in the waste accumulation site of the present invention, in the waste accumulation site composed of the ground or a wall and a floor made of a rigid material, the water impervious sheet is spread on the wall and the floor. It is characterized by having done.

[0006]

INDUSTRIAL APPLICABILITY The present invention relates to a water barrier sheet, particularly a water barrier sheet having excellent pressure resistance that can be used in a place where industrial waste is accumulated, while maintaining the characteristics of the conventional water barrier sheet. In addition to the drainage, deaeration and cushioning properties, we conducted a thorough study to find that a non-woven fabric is pressed against both sides of a thermoplastic resin sheet in a heat-melted state.
A laminated sheet obtained by fusion bonding to form a composite layer, and by using a resin having a melting point lower than that of the non-woven fabric constituent fibers, the non-woven fabric has a water permeability coefficient in a specific range within a specific range. It has been clarified that it is possible to provide a water-impermeable sheet that can be adjusted to the above condition and that satisfies all the above conditions.

In particular, the water-blocking sheet of the present invention is characterized in that a composite layer composed of fibers constituting the non-woven fabric and a polymer constituting the resin sheet is formed. By forming such a composite layer, although it has a high apparent rigidity and is a suitable material that can be used as a wall material and a floor material, the restoration property after being wound and left (flexibility) sex)
It was possible to impart the characteristics of excellent workability and workability to that extent, and this property was achieved for the first time by the present invention.

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a cross-sectional view of a typical water-impervious sheet of the present invention, where 1 is a nonwoven fabric layer, 2 is a thermoplastic resin sheet, and 3 is a thermoplastic resin sheet.
Is a composite layer. What is important here is that the melting point of the polymer forming the thermoplastic resin sheet 2 is lower than the melting point of the fibers forming the nonwoven fabric layer 1. By adopting such a low melting point resin, the advantages of the nonwoven fabric layer as a nonwoven fabric can be effectively utilized, and the composite layer 3 utilizing the fibers of the nonwoven fabric is
Surprisingly, the completely unexpected effect of significantly improving the restoration (flexibility) and workability was achieved.

The fibers constituting the non-woven fabric layer 1 of the present invention are preferably fibers made of a polymer having a relatively high melting point such as polyester, polyamide, polypropylene, polyphenyl sulfone, and fluororesin. Further, industrial wastes include substances having strong acidity and strong alkalinity, chemical resistance is required, and since they are often deposited outdoors, those having excellent weather resistance are desired. Considering these points, for example, fibers made of polypropylene, polyphenyl sulfone, fluororesin, etc. are convenient for use in places where industrial wastes are left to be deposited and left outdoors for a long period of time. Further, among these fibers, when strength characteristics are required, a nonwoven fabric composed of long fibers is preferably used. Further, when weather resistance is desired, fibers made of the above-mentioned specific resin can be used. For example, even in a polyester fiber non-woven fabric, the weather resistance can be improved by containing carbon black. Such carbon black is preferably contained in the range of 0.2 to 0.6% with respect to the weight per 1 m _{2 of the} nonwoven fabric. The content may be any of impregnation, coating, and primary coating, but primary coating is preferable from the viewpoint of durability and the like. If it is less than 0.2%, the weather resistance cannot be expected to increase, and if it exceeds 0.6%, the needle resistance in the production process of the non-woven fabric tends to increase and the productivity tends to deteriorate, which is not preferable.

The single yarn fineness of the fibers constituting the non-woven fabric layer 1 is preferably 1 to 7 d, more preferably 3 to 5 d, from the viewpoint of physical properties required for the non-woven fabric, particularly strength and water permeability.
The range of is good. In the nonwoven fabric of the present invention,
It does not matter if fibers having different fineness are mixed and the average single yarn fineness is within the above range. The weight of such a non-woven fabric is preferably 100 to 600 g / m 2.
² , more preferably 200 to 400 g / m ² . In addition, the thickness of the nonwoven fabric layer 1 is
It is preferably 1 mm or more, more preferably 3 to 6 mm. Here, the basis weight and the thickness are numerical values of only the nonwoven fabric layer 1 excluding the composite layer 3.

Next, as the resin constituting the thermoplastic resin sheet 2 of the present invention, a resin having a lower melting point than the fiber used is used. Further, like the fibers, a thermoplastic resin having excellent chemical resistance and weather resistance is preferably used. The resin having a low melting point is preferably a resin having a melting point lower than that of the fiber by 20 ° C. or more, more preferably 50 ° C. or more, and particularly preferably 80 ° C. or more. As such a resin, for example, a polyolefin resin is preferably used. As such a polyolefin resin, for example, at least one selected from polyethylene, polypropylene and ethylene vinyl acetate copolymer resin is preferably used. Among these resins, polyethylene is preferable, and among these polyethylene, high-density polyethylene is more preferably used in view of chemical resistance and strength characteristics. In the present invention, a particularly preferable combination is a resin sheet of high density polyethylene (melting point = 130 ° C.) and a nonwoven fabric of polyester (melting point = 235 ° C.) fibers.

The thickness of the thermoplastic resin sheet of the present invention is 0.
(Composite layer only), but preferably 0.1-3 mm,
Preferably, those having a range of 0.5 to 2 mm are used in terms of strength, resilience and workability. In the present invention, even if the thickness of the resin sheet alone is 0, if the composite layer 3 is present, the function as a water-blocking sheet is sufficiently achieved, but from the viewpoint of sheet strength and durability, Those having a sheet thickness are preferred. Here, the resin sheet thickness is the numerical value of the sheet portion of the resin 100% excluding the composite layer 3. Of course, when the resin sheet is melt-fed, the heat-resistant reinforcing fiber may be contained in advance. In any case, the resin sheet of the present invention preferably has a tensile strength of 150 to 350 Kgf / cm ² ,
More preferably, those having a tear strength of 30 to 170 Kgf / cm are used. Such performance is preferable in terms of durability. That is, the water-impermeable sheet of the present invention is preferably premised to have an external pressure of at least 3 kg / cm ² ,
Furthermore, it has a function and structure that poses no problem even under an external pressure of 5 kg / cm ² . Therefore, the water permeability of the nonwoven fabric sheet is maintained as a function under such external pressure. As described above, the water-impermeable sheet of the present invention is characterized by having the composite layer 3. This composite layer 3
Is not formed by forming the thermoplastic resin sheet as in the conventional method and then sandwiching the sheet with a non-woven fabric and heating and pressing to press-bond the sheet. Generally-used non-woven fabrics are used that have a higher fiber density by being fused or punched in order to increase the fabric strength. The non-woven fabric used in the present invention is the composite layer 3 And a fiber having a specific fiber density are used in order to form water vapor and to ensure water permeability in the in-plane direction. That is, a fiber having a fiber density of preferably 0.8 to 1.3 g / cm ³ , and more preferably 1.0 ± 0.1 g / cm ³ is used. Since the non-woven fabric having such a fiber density sandwiches the molten resin and presses it with a nip roll, it is possible to obtain excellent resilience.
It was possible to form a composite layer having a preferable thickness of 0 to 500 μ. Here, the thickness of the composite layer 3 is the numerical value of the composite layer on one side excluding the sheet portion of the resin 100%. Therefore, when the thickness of the resin sheet is 0, The thickness is doubled to 200 to 1000 μ. A more preferable range of the thickness of the composite layer 3 is 200 μ to 300 μ. If the thickness is less than 100 μ, the restorability (flexibility) and the workability are deteriorated, and, of course, the adhesion between the nonwoven fabric and the resin sheet is insufficient and the durability tends to be deteriorated. On the other hand, when it exceeds 500 μ, the workability and durability are maintained, but the nonwoven fabric layer 1 is reduced, and the air permeability, the drainage property, and the buffer property tend to be insufficient. Of course, if a non-woven fabric having a thickness corresponding to the reduction of the non-woven fabric layer is used, this problem can be solved, but it is not economical that the thickness is too thick.

The above-mentioned non-woven fabric is described as a non-woven fabric composed of fibers having a uniform fiber density and the same single yarn fineness, but in the present invention, such non-woven fabric is composed of fibers of different fineness separately. Even non-woven
Further, even if it is a laminated body made of a nonwoven fabric of different fiber density,
Icicle may be a non-woven fabric obtained by mixing and mixing these. For example, a non-woven fabric having a low fiber density and a non-woven fabric having a high fiber density are laminated by a melt blow method, a bunching method, an adhesive method, or the like, and a molten resin is sandwiched and pressed on the low fiber density side of the nonwoven fabric laminate. As a result, it is possible to provide a water-impermeable sheet having more excellent effects described above.

Further, it is preferable that the non-woven fabric layer 1 of the present invention has a bridging function on the deposit contact side. That is, the non-woven fabric layer 1 includes a columnar member having a function of resisting compression of the non-woven fabric itself by an external pressure. This member may be metal or plastic as long as it has hardness and toughness against the external pressure.

Next, a method of manufacturing the water-blocking sheet of the present invention will be described with reference to FIG. FIG. 2 is a schematic process diagram showing a method for manufacturing the sheet. First, the nonwoven fabric 6 wound around the delivery roll 7 is conveyed so as to be supplied to the nip roll 8 and the cooling roll 9. A T-die 4 is provided above the rolls 8 and 9, and a thermoplastic resin 5 is charged into the T-die 4 and melted. The molten resin is supplied from the T-die 4 in a sheet form between the rolls 8 and 9, and is nipped while being cooled to be integrated with the nonwoven fabric. The integrated sheet is further solidified by the cooling roll 10,
It is wound around the take-up roll 11.

By setting the clearance between the nip roll 8 and the cooling roll 9 and the nip pressure, the thickness of the composite layer and the resin sheet thickness can be determined. Of course, the above-mentioned thickness is changed depending on the fiber density, the viscosity of the molten resin, etc., and it is necessary to consider these conditions when manufacturing.

[0017]

EXAMPLES The present invention will now be described in more detail by way of examples.

The characteristics in the examples were evaluated by the following methods.

Strength characteristics: Based on JIS L1096.

Abrasion resistance: Based on JIS L-1096 (Scott method).

Permeability in the in-plane direction: The measuring method is JIS A-1.
According to 218, vertical (V) × horizontal (H) is 10 cm ×
Use a non-woven fabric specimen with an arbitrary thickness (X cm) of 28 cm. When preparing this test piece, both sides are melt-cut by a heat cutter to prevent water leakage from the sides.
This sample is placed on a sample table composed of a rubber sheet of the water permeability test apparatus of FIG. 4 installed in a thermostatic chamber, and then the surface of the sample is also completely covered with the rubber sheet to complete the mounting of the sample. Then, compressed air is sent to the air chamber of the test apparatus by a compressor to adjust the pressure in the chamber to 0.1 kg / cm ² . Next, water is passed from a water reservoir at a constant water level (ΔT = T1−T2 = 14 cm), and the amount (W) of water flowing through the sample is measured with a graduated cylinder for a fixed time (S: seconds). The in-plane hydraulic conductivity (K) is calculated by the following calculation formula.

K (cm / sec) = [V · W · Z] / [ΔT
・ 10X ・ S] In the formula: V = 28 cm, W = outflow water amount (cm ³ ), Z = temperature correction value ΔT = 14 cm, 10X = H ・ X = cross-sectional area (cm ² ), S =
Measurement time (sec) Example 1 A water-blocking sheet was manufactured by the process of FIG.

That is, as the non-woven fabrics to be used, two non-woven fabrics having a basis weight of 300 g / m ² and a fiber density of 1.0 g / cm ³ made of undyed polyester continuous fibers containing 0.2% by weight of carbon black having a single yarn fineness of 3d were sent out. On roll 7,
Each was loaded and a guide cloth was connected to the ends of these nonwovens, and the guide cloth was used to complete the line of the process. The clearance between the nip roll 8 and the cooling roll 9 is 2
mm, the nip pressure was set to 6 Kgf / cm ² , high density polyethylene was charged into a T die for a resin sheet, and the temperature was raised to 180 ° C. to melt.

When the process line is operated and the connecting portion between the non-woven fabric and the guiding fabric passes through the nip roll 8,
A sheet of molten high-density polyethylene was supplied from a T-die. The sheet heat-sealed by the nip roll 8 and the cooling roll 9 passed through the cooling roll 10, was further cooled and solidified, and was then wound on the take-up roll 11.

Table 1 shows the physical properties of the obtained water-blocking sheet.

Comparative Example 1 The non-woven fabric and the thermoplastic resin used in Example 1 were used, but the thermoplastic resin used was a high-density polyethylene sheet previously formed into a sheet having a thickness of 2 mm. This sheet was sandwiched between two non-woven fabrics and pressure-bonded with a calender roll heated to 200 ° C. under the condition of a nip pressure of 6 Kgf / cm ² . (Comparative Example 1) Table 1 shows the physical properties of the obtained water-permeable sheet.

Comparative Example 2 The non-woven fabric and the thermoplastic resin used in Example 1 were used, but the thermoplastic resin was previously formed into a sheet having a thickness of 1 mm,
A high density polyethylene sheet was used. A synthetic rubber adhesive was applied to both sides of this sheet, sandwiched between two sheets of non-woven fabric, and air-dried at room temperature for adhesion. Comparative Example 2 Table 1 shows the physical properties of the obtained water-permeable sheet.

Comparative Example 3 The high-density polyethylene of Example 1 was melted into a sheet having a thickness of 1 mm. This sheet was evaluated as a water barrier sheet. The results are shown in Table 1.

[0029]

[Table 1] As is clear from Table 1, the water impervious sheet of Example 1 has considerably increased strength characteristics as compared with high density polyethylene. Also, although the apparent bending resistance is higher than that of high-density polyethylene, the restorability and flexibility are significantly superior. In addition, although the breaking elongation of Example 1 is reduced, this numerical value is
This value is almost the same as the elongation of the nonwoven fabric alone. Further, with respect to abrasion, the example 1 showed a very strong result.

The non-woven fabric has an in-plane water permeability coefficient of 10 ^-1 cm / sec and has a good drainage property. Further, it can be seen that the frictional force is larger than that of the resin sheet alone, and the workability of the slope with a large inclination is excellent.

[0031]

EFFECTS OF THE INVENTION According to the water-impermeable sheet of the present invention, it is a sheet which has the characteristics of the conventional water-impermeable sheet as it is, and is excellent in cushioning property, restorability, and workability, and drainage property and dewatering property. It is possible to provide a water-impermeable sheet having excellent vapority and a waste accumulation site made of the same that has excellent durability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of the water blocking sheet of the present invention.

FIG. 2 is a schematic view showing an example of a process for producing the water-blocking sheet of the present invention.

FIG. 3 is a cross-sectional view of the water blocking sheet for an industrial waste treatment plant of the present invention.

FIG. 4 is a schematic diagram showing an apparatus and method for measuring the in-plane water permeability coefficient of a nonwoven fabric constituting the water-blocking sheet of the present invention.

[Explanation of symbols]

 1: Nonwoven fabric 2: Resin sheet 3: Composite layer 4: T-die 5: Thermoplastic resin 6: Nonwoven fabric 7: Sending roll 8: Resin nip roll 9: Cooling embossing roll 10: Cooling roll 11: Take-up roll

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location E02D 17/20 103 B // B29K 101: 12 105: 06

Claims (15)

[Claims] 1. A laminated sheet comprising a thermoplastic resin sheet and non-woven fabrics fused on both sides thereof, wherein the melting point of the polymer constituting the resin sheet is lower than that of the fibers constituting the non-woven fabric, and the non-woven fabric layer. At the interface of the thermoplastic resin sheet and a composite layer composed of fibers constituting the non-woven fabric and a polymer constituting the thermoplastic resin sheet,
And the water permeability coefficient of the non-woven fabric layer on one side in the in-plane direction is 5 kg.
A water barrier sheet having a pressure of 1 × 10 ⁻³ cm / sec or more under a pressure of / cm ² . 2. The non-woven fabric layer on one side has an in-plane water permeability coefficient in the range of 10 ^-1 to 10 ^-2 cm / sec under a pressure of 5 kg / cm ^2. Item 1. An impermeable sheet according to item 1. 3. The non-woven fabric layer on one side is 100 to 600 g.
The water impervious sheet according to claim 1, which has a basis weight of / m ² . 4. The composite layer on one side is at least 100 μm.
The water-impermeable sheet according to claim 1, which has a thickness of. 5. The thermoplastic resin sheet is 150-35.
The waterproof sheet according to claim 1, which has a tensile strength of 0 kgf / cm ² and a tear strength of 30 to 170 kgf / cm ² . 6. The waterproof sheet according to claim 1, wherein the thermoplastic resin sheet is made of a polyolefin resin. 7. The waterproof sheet according to claim 1, wherein the thermoplastic resin sheet is reinforced and reinforced with fibers or a filler. 8. The waterproof sheet according to claim 1, wherein the nonwoven fabric layer includes a columnar member having a bridging function in the nonwoven fabric layer. 9. The waterproof sheet according to claim 1, wherein the thermoplastic resin sheet has a thickness of 1 mm or more. 10. The waterproof sheet according to claim 1, wherein the non-woven fabric layer contains carbon black. 11. A water impervious sheet, characterized in that a thermoplastic resin having a melting point lower than that of fibers constituting the nonwoven fabric is melted and supplied between a plurality of nonwoven fabric sheets, and these are pressed. Manufacturing method. 12. The pressing causes the non-woven fabric layer on one surface to have a water permeability coefficient of 1 × 10 ⁻³ under a pressure of 5 kg / cm ^2.
The method for producing a water-blocking sheet according to claim 11, wherein the method is adjusted to cm / sec or more. 13. A non-woven fabric is fused on both sides of a thermoplastic resin sheet to a wall or floor at a waste accumulation site composed of a ground or a wall made of a rigid material and a floor. A laminated sheet, wherein the melting point of the polymer forming the resin sheet is lower than the melting point of the fibers forming the nonwoven fabric layer, and the nonwoven fabric is formed at the interface between the nonwoven fabric layer and the thermoplastic resin sheet. composite layer consisting of a polymer constituting the fibers and the thermoplastic resin sheet is formed, and the permeability in the in-plane direction of the one side of the nonwoven fabric layer is under a pressure of 5Kg / cm ² 1 × 10 ^- A waste accumulation site characterized by spreading a water-blocking sheet with a speed of ³ cm / sec or more. 14. The waste deposit site according to claim 12, wherein the water barrier sheet is used in which the wall portion and the floor portion are made of a thermoplastic resin sheet reinforced by fibers or a filler. 15. The waste deposit site according to claim 13, wherein the wall portion and the floor portion are formed of a water blocking sheet including a columnar member having a bridging function in the nonwoven fabric layer.