JPH0748825A - Culvert drain pipe - Google Patents

Abstract

PURPOSE:To provide a culvert drain pipe exerting an excellent filtering action without, causing clogging and capable of being used over a long period. CONSTITUTION:Two or more synthetic resin oriented films having many slits in the drawing directions are overlapped and fused on the outer layer 2 of a pipe wall so that the drawing directions are made perpendicular to each other, and slurry is smoothly fed in a pipe through many fine holes 3 formed by the crossing of the slits. A thin nonwoven fabric 4 is integrally overlapped as an inner layer on the inner periphery of the outer layer 2, and a filtering action is performed by the nonwoven fabric 4. The nonwoven fabric 4 is protected by the oriented films having large tensile strength, and it can be used over a long period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underdrain drainage pipe which is used by being buried in a golf course, a wetland, or other ground.

[0002]

2. Description of the Related Art Conventionally, as a drainage pipe of this kind, as described in Japanese Utility Model Publication No. 54-27206,
The tape-shaped net is spirally wound so that the side edges thereof are sequentially overlapped with each other to form inner and outer layers, and a filter made of non-woven fabric or glass fiber or other woven fabric is interposed between these layers, and further, resin is used. A structure is known in which a reinforcing strip is fused and fixed in a spiral shape on the inner and outer circumferences of a pipe.

[0003]

Such an underdrain drainage pipe is laid in the underdrain formed under the ground, and filters the muddy water that permeates under the ground by a filter and guides it into the drainage pipe. However, there are various types of soil in the place where the underdrain drainage pipe is buried, such as mud, clay or gravel, and the above-mentioned underdrain drainage pipe cannot handle all of these soil types.

That is, the net forming the inner and outer layers of the tube is used for the purpose of maintaining the shape and strength of the tube, and since the mesh is extremely rough, it has a filtering effect. However, the nonwoven fabric serves only as a filter. Therefore, it is necessary to use a relatively thick non-woven fabric, which increases the water passage resistance and performs the filtering action through the gap between the fibers caused by the entanglement of the fibers, which increases the thickness. Then, it becomes difficult to pass the fine particles of the mud, and the fine particles remain and accumulate between the fibers of the surface layer of the filter to cause clogging, which causes a problem that the particles cannot be used in a short period of time.

Further, the net forming the inner and outer layers of the pipe is easily stretched by a tensile force during handling or piping, and the nonwoven fabric is damaged by the stretching force and cannot perform a filtering action. However, there is a problem such as the inflow and accumulation of muddy water in the drainage pipe, and since the nonwoven fabric is exposed to the outside through the coarse mesh of the net, it may be damaged by rubbing against earth and sand. It was

[0006] Further, a woven cloth woven by a narrow flat yarn is also used as a filter, but since the mesh is relatively coarse, sand may pass through. Not only that, but misalignment causes sand soil to flow in more severely, which makes it unsuitable for use as an underdrain drainage pipe. The present invention provides a underdrain drainage pipe that is capable of exhibiting stable drainage performance for a long period of time without being affected by soil properties and without causing clogging.

[0007]

In order to achieve the above object, the underdrain drainage pipe of the present invention has two or more synthetic resin stretched films having a large number of parallel cuts in the stretching direction, and the cut directions are orthogonal to each other. A film having a large number of pores formed by polymerizing and fusion-bonding is used as the outer layer of the tube wall, and a thin non-woven fabric having a thickness of 0.5 mm or less is polymerized as the inner layer on the inner peripheral surface of the outer layer. It has a structure. A reinforcing strip may be spirally wound around the outer peripheral surface of the tube.

[0008]

The outer layer of the wall of this underdrain drainage pipe is formed by polymerizing and fusing two or more stretched films having a large number of parallel cuts so that the cut directions are orthogonal to each other. Since it is made of a film, it can protect the non-woven fabric arranged as an inner layer by covering it entirely, and can prevent the thin non-woven fabric from being torn by sliding contact with the sand and polymerization of the stretched film. The film is
Since the tensile strength is extremely high, the tensile force does not act on the non-woven fabric even if the pipe is pulled when the pipe is laid in the underdrain. Therefore, the non-woven fabric can be used for a long period of time. Is.

Further, the thickness of the stretched film is thin, and the large number of pores formed by the crossing of the cuts provided in the film and the polymerization are always maintained in a predetermined size and shape and are directly passed through the tube. Since they communicate with each other, the resistance to the passage of water is extremely small, and the mud water in the soil flows quickly and easily through the pores, enabling smooth drainage, and the particles of the mud can also pass through with the mud water to eliminate clogging. Moreover, even if the pores are closed by gravel, the gravel itself exerts a filtering action, so that the drainage capacity is not reduced.

Further, the large soil particles that try to pass through the pores are prevented from passing into the pipe by the non-woven fabric polymerized on the inner peripheral surface side of the film having the pores,
Only small particles can pass through together with water. In this case, since the nonwoven fabric is thin, the particles do not remain between the fibers of the nonwoven fabric and easily pass through the tube without causing clogging. If the reinforcing strip is spirally wound around the outer periphery of the tube, the torsional strength and pressure resistance of the tube can be maintained.

[0011]

Embodiments of the present invention will now be described with reference to the drawings.
In FIGS. 1 and 2, reference numeral 1 denotes a cylindrical tube wall which mainly constitutes a drainage pipe, and an outer layer is a polymer film 2 having a large number of square pores 3, 3, ... 0.5 mm,
Preferably, the non-woven fabric 4 having a thickness of 0.2 mm or less is superposed as an inner layer and partially adhered and integrated, and the reinforcing strip 5 is spirally wound around the outer peripheral surface of the pipe wall 1 at a constant pitch, It is fused and integrated.

Polymerized film 2 forming the outer layer of the tube wall
Is generally called split cloth, and has a thickness of 0.07-
For film such as polyethylene film of about 0.15 mm,
A split film having a large number of cuts in the stretching direction is used, and at least two films having the large number of cuts are crossed by polymerizing and fusing so that the cutting direction and the stretching direction are orthogonal to each other. A large number of pores 3 are formed in the portion, and the size of the pores 3 can be appropriately changed depending on the width between the cuts, but it is preferably 1.0 mm or less, and about 0.2 mm.

The polymer film 2 is formed by weaving flat stretched narrow band-shaped stretched yarns having a shape obtained by separating the stretched film through cuts, and fusing the crossing portions of the vertical and horizontal flat yarns together. It may have a structure. On the other hand, the porosity of the non-woven fabric 4 forming the inner layer of the tube wall 1 is not more than half the porosity of the polymer film 2 and the fibers of the non-woven fabric 4 pass through the voids of the pores 3 of the polymer film 2. The structure is exposed.

FIGS. 3 and 4 show another embodiment of the present invention. The stretched polymer film 2, 2'having the above-mentioned non-woven fabric 4 as an intermediate layer of the tube wall and the large number of pores 3 inside and outside thereof. The pipe wall 1 is formed in a state where the pipe walls 1 are superposed and integrated. That is, in the above-described embodiment, the non-woven fabric 4 has a structure in which the polymer film 2'is disposed on the inner peripheral surface side and the non-woven fabric 4 is sandwiched between the inner and outer films 2 and 2 '.

In order to manufacture such an underdrain drainage pipe, as shown in FIG. 5, the polymer film 2 and the non-woven fabric 4 for forming the pipe wall 1 are strip-shaped film 2a and strip-shaped non-woven fabric having a desired width.
4a, and the strip-shaped film 2a and the strip-shaped nonwoven fabric 4a can be obtained by spirally winding and unifying the strip-shaped nonwoven fabric 4a on a rotational molding shaft (not shown) so that their side edges are sequentially overlapped.

More specifically, first, the belt-shaped film 2a is first wound on the rotational molding shaft so that the film portion to be wound next overlaps the surface of the film portion to be wound in a single winding state by a width of 1/2, that is, The tape is wound in a spiral shape with a pitch shift of 1/2, and at this time, a narrow binder member 6 is inserted so as to overlap one end edge of the strip film 2a and the width of the strip film 2a is reduced. The band-shaped nonwoven fabric 4a having a width of about 1/2 of the band-shaped film 2a is spirally wound in a state of being overlapped on one half portion, and the binder member 6 is heated and melted, so that both end edges of the band-shaped nonwoven fabric 4a are removed. The pipe wall is formed by integrally adhering to the strip film 2a.

Further, at the time of forming this tube wall, a reinforcing strip 5 made of thick polyethylene resin or the like is spirally formed at the same pitch on the other end of the strip-shaped film 2a forming the outer layer via a binder member 7. The binder member 7 is wound into a circular shape, and the binder member 7 is heated and melted to be wound and integrated.

In the underdrain drainage pipe thus obtained, the other half of the strip-shaped film 2a is coated on the strip-shaped nonwoven fabric 4a to form the outer layer of the pipe, and the strip-shaped nonwoven fabric 4a is arranged in the intermediate layer. One half of the film 2a forms an inner layer to form the underdrain drainage pipe shown in FIG.
In the case of forming an underdrain drainage pipe consisting of a double layer as shown in, the strip-shaped nonwoven fabric 4a on the rotational molding shaft, spirally wound while polymerizing and adhering both edge portions of each other, on this strip-shaped nonwoven fabric 4a Similarly, the strip-shaped film 2a may be wound in a spiral shape, and the appropriate place may be bonded to the strip-shaped nonwoven fabric 4a through an appropriate bunder. The underdrain drainage pipe configured as described above is drawn and laid in the underdrain under the ground to perform the above drainage action.

[0019]

As described above, according to the underdrain drainage pipe of the present invention, two or more stretched films having a large number of parallel cuts are polymerized and fused so that their cut directions are orthogonal to each other. The polymerized film with holes is used as the outer layer of the tube wall, and the inner peripheral surface of the outer layer is a thin non-woven fabric with a thickness of 0.5 mm or less. Not only is it easy to handle, but it also has excellent flexibility, making piping work easy during installation.
Moreover, the non-woven fabric arranged as the inner layer is entirely covered and protected by the polymerized stretched film, and the thin non-woven fabric can be prevented from being broken by sliding contact with earth and sand. Since the tensile strength of the film is extremely high, even when the pipe is pulled in the underdrain or when the pipe is pulled due to earth pressure, etc., almost no tensile force acts on the non-woven fabric and damage to the pipe wall is eliminated. It can be used for a long time.

Further, the thickness of the stretched film is thin, and the large number of pores formed by the crossing of the cuts provided in the film and the polymerization are always maintained in a predetermined size and shape and are directly passed through the tube. Since they communicate with each other, the passage resistance of water is extremely small and mud water in the sand and sand can be quickly and easily distributed through the pores, thus enabling smooth drainage and allowing fine particles of mud to pass along with the mud water and clogging. In addition, even if the pores are closed by gravel, the gravel itself exerts a filtering action,
Does not reduce drainage capacity.

Further, the large soil particles that are about to pass through the pores are prevented from passing into the pipe by the non-woven fabric polymerized on the inner peripheral surface side of the film having the pores,
Only small particles can pass through together with water. In this case, the non-woven fabric is thin, so the micro-particles do not remain between the fibers of the non-woven fabric and can easily pass through the pipe to ensure reliable and good drainage over a long period of time. Can be played.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of Example 1.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a partially cutaway side view of Example 2;

FIG. 4 is a partially enlarged sectional view of FIG.

FIG. 5 is a cross-sectional view for explaining the manufacturing method.

[Explanation of symbols]

 1 Tube Wall 2 Polymerized Stretched Film 3 Pore 4 Nonwoven Fabric

Claims (2)

[Claims] 1. A tube having a large number of pores formed by polymerizing and fusing two or more synthetic resin stretched films having a large number of parallel cuts in the stretching direction so that the cut directions are orthogonal to each other. An underdrain drainage pipe, characterized in that it is an outer layer of a wall, and a thin non-woven fabric having a thickness of 0.5 mm or less is integrally polymerized as an inner layer on the inner peripheral surface of the outer layer. 2. The underdrain drainage pipe according to claim 1, wherein the film is used as inner and outer layers of a pipe wall, and the non-woven fabric is interposed therebetween as an intermediate layer.