JP2004300804A - Drain member and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drain member for having sufficient strength and securing sufficient voids even when using a recycled article as a raw material, and to provide its manufacturing method. <P>SOLUTION: The drain member charges the raw material consisting of the recycled article of a thermoplastic resin in an extrusion vessel forming a plurality of extrusion holes at a plurality of concentrically circular positions on an extrusion face, extrudes the extrusion raw material from the extrusion holes, and welds a plurality of string-like extrusion materials 18 and 19 at mutual contact points to be wholly molded into prescribed shape. In the extrusion hole, the diameter of the extrusion hole of three 3-equally arranged positions on the same circle is larger than that of the extrusion hole of the other position, and the three thick extrusion materials 19 are core materials. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a drain member used in a liquefaction prevention method or a drainage material for suppressing liquefaction of the ground when an earthquake occurs, and a method of manufacturing the drain member.
[0002]
[Prior art]
When an earthquake with a seismic intensity of 5 or more occurs, the pressure of groundwater penetrating into the gaps increases in the soft stratum composed of underground sand and silt, etc., the geology itself liquefies and flows, losing its bearing capacity Therefore, muddy water pierces the weak ground and spills out onto the ground.
[0003]
Therefore, in order to suppress such a liquefaction phenomenon as much as possible, conventionally, a liquefaction prevention method for dissipating pore water pressure rising during an earthquake has been proposed. 5 and 6 are views showing this conventional liquefaction prevention method. First, a casing pipe 41 is mounted on a drilling machine 40 shown in FIG. 5, and as shown in FIG. The bit 42 at the end of the casing tube 41 is opened with the 41 kept horizontal, and the drain member 43 is inserted into the casing tube 41. Thereafter, the bit at the end of the casing tube is closed, and as shown in FIGS. 6B and 6C, the casing tube 41 is made vertical, and the casing tube 41 is rotated by a drilling machine and screwed into the ground. Then, as shown in FIGS. 6D and 6E, after the casing tube 41 reaches a predetermined depth, the tip bit 42 is opened, and the drain 43 is left underground, and as shown in FIG. 6F. As described above, the casing tube 41 is pulled out from the ground by rotating in the reverse direction.
[0004]
As a drain member used in such a liquefaction prevention method, a thermoplastic resin made of polypropylene is heated and extruded in a string form from a large number of small holes in a fluidized state. A molded article obtained by entanglement and fusion at the contact point is used. This molded body has large voids because a plurality of cords are entangled in a noodle shape. Then, by using this molded body as a drain member, it is possible to prevent the stratum from being collapsed due to having sufficient strength, and to secure a sufficient space as a passage for groundwater.
[0005]
[Problems to be solved by the invention]
However, the conventional drain member uses a newly synthesized polypropylene (new product). However, due to the recent social demand for the formation of a recycling-based society, there is also a demand for recycling this polypropylene material. Extremely strong. However, when recycled polypropylene (recycled product) is used as the drain member, the recycled product has a lower strength, particularly the bending strength, and the drain member is manufactured using a conventional new product for the recycled product. However, there is a problem that a drain member having a sufficient strength cannot be manufactured even if the method is applied as it is. Further, since the drain member needs to secure a sufficient space and also needs to be lightweight, it is not possible to secure the strength by molding a thermoplastic resin into a plate shape, for example. Further, when the strength of the extruded material is low, the cord-shaped extruded material is disconnected during the manufacturing process, and it is difficult to form the extruded material into a predetermined shape (such as a cylindrical shape).
[0006]
The present invention has been made in view of such a problem, and provides a drain member having sufficient strength and securing a sufficient gap even when a recycled product is used as a raw material, and a method for manufacturing the same. The purpose is to do.
[0007]
[Means for Solving the Problems]
The drain member according to the present invention is a drain member that is formed into a predetermined shape as a whole by welding a plurality of cord-like materials obtained by extruding a fluid regenerated raw material at their mutual contact points, and has the same circular shape. The string-like material extruded from the three equally spaced points above is thicker than other string-like materials.
[0008]
In this drain member, the recycled material may be a recycled polypropylene product.
[0009]
Further, the method of manufacturing a drain member according to the present invention includes the steps of: loading a recycled material into an extrusion container having a plurality of extrusion holes formed at a plurality of concentric positions on an extrusion surface; And a method of manufacturing a drain member in which a plurality of obtained string-shaped extruded materials are welded at their mutual contact points and formed into a predetermined shape as a whole, wherein the extruded holes are arranged at three equally spaced positions on the same circle. Is characterized in that the diameter of the extrusion hole is larger than the diameter of the extrusion hole at another position.
[0010]
In this method of manufacturing a drain member, the recycled raw material may be a recycled polypropylene.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a drain member according to an embodiment of the present invention, FIG. 2 is a sectional view showing a manufacturing apparatus thereof, and FIG. 3 is a plan view of a mold. The drain member of the present embodiment is formed into a cylindrical shape as a whole by entanglement of a number of string-shaped extruded materials 1 and 1a and fusing them together at their contact points.
[0012]
Among the numerous extruded raw materials 1 constituting the molded body, the raw material 1 a extruded from three equally-placed circles around the axis of the cylinder has a diameter larger than that of the other extruded raw materials 1. . The raw materials 1 and 1a are obtained by extruding a recycled product of a thermoplastic resin such as polypropylene.
[0013]
In the manufacturing apparatus of the drain member 1, the extrusion head 10 connected to an extruder main body (not shown) is disposed above a container 25 storing water 26. A flange is provided at the lower end of the container of the head 10, and a bolt insertion hole is formed in the flange. The lower surface of the head 10 is constituted by a disk-shaped mold 12, and the mold 12 has a hole 16 provided in a peripheral portion thereof and a hole provided in the flange portion of the head 10. Is fixed to the lower portion of the head 10 by inserting a bolt 15 through the nut and tightening the mold and the flange with a nut. A screw 20 is fixed to the center of the lower surface of the mold 12 with its longitudinal direction perpendicular to the screw. A screw hole formed at the upper end of the support rod 21 is screwed into the screw 20 so that the support rod 21 is suspended at the center of the mold 12.
[0014]
Further, a screw 22 is formed at a lower end of the support rod 21, and a screw hole formed in an upper half portion of the core 23 is screwed into the screw 22 so that the core 23 is fixed to the lower end of the support rod 21. It is fixed to the part.
[0015]
A sheet-shaped band heater 11 is arranged on the outer surface of the head 10 so as to surround the head 10. The extruded material in the head 10 is heated by the band heater 11.
[0016]
At the center of the water storage container 25, a cylindrical receiving portion 24 is provided so as to surround the core 23 as a center. The receiving portion 24 is an inclined portion 24a whose upper half opens upward. The extruded material is collected on the center side by the inclined portion 24a, passes through the gap between the core 23 and the receiving portion 24, enters the water 26 in the water storage container 25, and is cooled by the water 26. The traveling direction of the container 25 is bent and pulled out from the outlet 27 provided on the side of the container 25. The receiving portion 24 (including the inclined portion 24a) and the core 23 are formed of a metal having excellent thermal conductivity such as copper, a copper alloy, or brass. If a material having low thermal conductivity, such as stainless steel, is used as the receiving portion 24 and the core 23, a high-temperature extruded material may adhere to the receiving portion 24 and the core 23.
[0017]
Thus, small holes 13 and large holes 14 are formed in the mold 12 so as to be arranged on three rows of concentric circles centered on the center. On the innermost arc and the outermost arc, only the small holes 13 are formed at equal intervals. On the other hand, large holes 14 are formed at three equally spaced positions on the central arc, and a plurality of small holes 14 are formed at regular intervals between the large holes 14. The large hole 14 has an inner diameter of, for example, 3.0 mm, and the small hole 13 has an inner diameter of, for example, 1.6 mm. Although the number of the large holes 14 is three as described above, the number of the small holes 13 is, for example, 48 in three rows of circles.
[0018]
Next, a method of manufacturing the drain member according to the present embodiment using the extrusion device configured as described above will be described. A recycled product obtained by recycling a waste material of a thermoplastic resin such as polypropylene is charged into the extruder body, heated to a predetermined temperature and pressed. The extruded raw material of this recycled product is extruded from the head 10 through the mold 12. At this time, the header 10 is heated to an extrusion temperature of 200 to 240 ° C. by the band heater 11. The extrusion temperature for a new product is usually 250 ° C., and for a regenerated product, the temperature is slightly lower than this.
[0019]
Then, as shown in FIG. 4, string-shaped or sheet-shaped extruded materials 18 and 19 are extruded from the small hole 13 and the large hole 14 of the mold 12, respectively. These materials 18 and 19 are collected by the inclined portion 24a of the receiving portion 24, pass through the gap between the receiving portion 24 and the core 23, enter the water 26, and are cooled. While passing between the receiving portion 24 and the core 23, they are in contact with each other and fused at a contact point, and are cooled and solidified by the receiving portion 24 and the core 23. As a result, as shown in FIG. 1, a string-shaped or sheet-shaped extruded material 18, 19 is entangled with each other to obtain a molded body formed into a cylindrical shape as a whole. The molded body is further cooled in water, bent laterally in the container 25, pulled out from the outlet 27, and cut into a predetermined length. This withdrawal speed is, for example, 80 to 180 cm / min.
[0020]
At this time, in the present invention, in addition to the small holes 13, the material extrusion holes of the die 12 are provided with three large holes 14 having a diameter larger than the small holes 13 (positions at a central angle of 120 °). The extruded material 19 extruded from the large hole 14 has a large diameter. Therefore, the three extruded materials 19 extruded from the large holes 14 become the core material in the molded body, and the extruded materials 19 extruded from the large number (for example, 48) of small holes 13 are extruded. By providing such a core material, the strength of the molded body is significantly increased.
[0021]
The material 19 extruded from the large hole 14 having an inner diameter of 3 mm has a diameter of 3.4 to 4.0 mm in the product, and the material 18 extruded from the small hole 13 having an inner diameter of 1.6 mm is a product. In this case, the diameter becomes 2.0 to 2.1 mm.
[0022]
The inner diameter of the large hole 14 is not limited to 3.0 mm as in the above embodiment, but may be set to 2 to 4 mm, for example. Also, the inner diameter 13 is not limited to 1.6 mm, and can be set to, for example, 1.2 to 1.8 mm. The number of the large diameters 14 is three. When the number of the large diameters 14 is even, for example, four, the strength of the molded body is lower than when the number is three. By making the number of the large diameters 14 an odd number, the strength of the molded body is improved. However, when the number is increased to five or seven, the weight of the molded body increases, which is not preferable. Therefore, the number of large diameters 14, that is, the number of large diameter extruded materials 19 is three.
[0023]
The present invention is not limited to the drain member used in the liquefaction prevention method, and can be used in various fields requiring a structure having a high porosity. For example, it can be used as a drainage material. That is, as a gutter for a parking lot or the like, a trench is dug in the ground, the drain members are arranged side by side in two or three rows, and these are stacked and arranged in three or four steps. By providing a filter to block the passage, filling the soil on this filter to form the ground, it is possible to prevent rainwater from passing through this drain member and draining into the ground, and to collect water on the ground of the parking lot. Can be prevented. Thereby, drainage of a parking lot or the like can be improved. In addition, by using the drain member of the present invention as an underground drainage material, soil can be improved. Further, by immersing the drain member of the present invention in water such as a reservoir, a water purifying action can be obtained and water quality can be improved. Furthermore, the present invention can also be used as a base for attaching a biofilm to sewage and factory wastewater in sewage treatment, factory wastewater treatment, and the like. Therefore, the drain member of the present invention is also effective as a member capable of obtaining a large contact area with a liquid or a gas.
[0024]
【Example】
Next, the effects of the embodiments falling within the scope of the present invention will be described in comparison with comparative examples that fall outside the scope of the present invention. By the method of the present invention and a conventional method (without large holes), a cylindrical molded body having an outer diameter of 100 mm and a length of 200 mm was formed. In the embodiment, the large diameter is 3.0 mm in inner diameter, the small diameter is 1.6 mm, the number of large diameters is 3, and the number of small diameters is 48. The comparative example has an inner diameter of 1.6 mm and 54 pieces.
[0025]
At this time, the mass of the molded product was 950 to 1100 g / m per 1 m in the example, and 1000 to 1200 g / m in the comparative example. The productivity was 850 to 1000 mm / min in the case of the example, and 700 to 800 mm / min in the case of the comparative example. In addition, the defective rate was 3 to 4% in the example, while 7 to 8% in the comparative example. Then, as a result of performing a compression test on the drain material made of this molded product, the maximum compression load in the vertical direction (axial direction of the cylinder) was 1.80 kN in the example, 1.68 kN in the comparative example, and horizontal in the vertical direction (axial direction of the cylinder). Regarding the direction (radial direction of the cylinder), the load when the deformation amount was 30% was 0.79 kN in the example and 1.07 kN in the comparative example. The test temperature was room temperature and the load application speed was 0.2 kN / sec.
[0026]
Therefore, according to the present invention, a molded product having high strength (particularly, compressive load) can be obtained, and a drain material having a small mass of a molded product can be obtained. Further, in the present invention, the productivity is high and the reject rate is low.
[0027]
【The invention's effect】
As described above in detail, according to the present invention, in a molded body formed by entanglement of a string-shaped extruded material, three of the many extruded materials are made thicker than other extruded materials, and In this, this thick extruded material was extruded from three equally spaced positions, so this thick extruded material became the core material in the molded body, and even if a recycled thermoplastic resin was used as the extrusion raw material, The strength of the body can be secured to be equal to or higher than that of using a new product. Thus, the present invention enhances the value of recycled products and greatly contributes to the formation of a recycling-based society.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a drain member according to an embodiment of the present invention.
FIG. 2 is a view showing an apparatus used for manufacturing a drain member according to the embodiment of the present invention.
FIG. 3 is a plan view showing the mold.
FIG. 4 is a perspective view showing the state of the extrusion.
FIG. 5 is a view showing a liquefaction prevention method.
6 (a) to 6 (f) are views showing a liquefaction prevention method in the order of steps.
[Explanation of symbols]
10: Header 12: Die 13: Small hole 14: Large hole 18: Extruded material (small diameter)
19: Extruded material (large diameter)
23: Core 24: Receiving part

Claims (4)

A drain member formed by extruding a plurality of string-like materials obtained by extruding a fluid regenerated raw material at points of mutual contact, and being formed into a predetermined shape as a whole, from three equally spaced points on the same circle. The extruded string-shaped material is thicker than other string-shaped materials. The drain member according to claim 1, wherein the recycled material is a recycled polypropylene product. A regenerated raw material is charged into an extrusion container having a plurality of extruded holes formed at a plurality of concentric positions on an extruding surface, and the regenerated raw material is extruded from the extruded holes to obtain a plurality of string-shaped extruded materials. The drain holes at the mutual contact points to form a predetermined shape as a whole, wherein the extrusion holes are arranged at three different positions on the same circle, and the diameter of the extrusion holes at other positions is different. A method of manufacturing a drain member, wherein the diameter is larger than the diameter of the drain member. The method for manufacturing a drain member according to claim 3, wherein the recycled material is a recycled product of polypropylene.

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