JP3729352B2 - Drain member and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drain member used for a liquefaction prevention method or a drainage material that suppresses the liquefaction phenomenon of the ground when an earthquake occurs, and a manufacturing method thereof.
[0002]
[Prior art]
When an earthquake with a seismic intensity of 5 or more occurs, the pressure of groundwater entering the gap in a soft stratum composed of underground sand, silt, etc. becomes high, the geology itself liquefies and flows, and loses its bearing capacity. Therefore, the muddy water pierces the weak ground and erupts to the ground.
[0003]
Therefore, in order to suppress such a liquefaction phenomenon as much as possible, a liquefaction prevention method for dissipating the 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 the drilling machine 40 shown in FIG. 5, and as shown in FIG. The bit 42 at the front end of the casing pipe 41 is opened in a state where the pipe 41 is horizontal, and the drain member 43 is inserted into the casing pipe 41. Thereafter, the bit at the tip 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 in the ground, as shown in FIG. 6F. Thus, the casing pipe 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 fluidized, and extruded from a large number of small holes into a string shape. For example, a molded product obtained by fusing at the contact point is used. This molded body has a large gap because a plurality of string-like bodies are entangled in a noodle shape. And by using this molded object as a drain member, since it has sufficient intensity | strength, it can prevent that a formation collapses and can ensure sufficient space | gap as a passage of groundwater.
[0005]
[Problems to be solved by the invention]
However, the conventional drain member uses newly synthesized polypropylene (new product). However, due to the social demand for the formation of a recycling society in recent years, there is a demand for recycling of this polypropylene material as well. Extremely strong. However, if a recycled polypropylene product (recycled product) is used as the drain member, the recycled product has lower strength, especially bending strength, and the drain member is manufactured using a conventional new product for the recycled product. Even if the method is applied as it is, there is a problem that a drain member having sufficient strength cannot be manufactured. Moreover, since it is necessary to ensure sufficient space | gap as a drain member, and also lightweight is required, for example, a thermoplastic resin cannot be shape | molded in plate shape and intensity | strength cannot be ensured. Further, if the strength of the extruded material is low, the string-shaped extruded material is disconnected in the manufacturing process, and it becomes difficult to form the extruded material into a predetermined shape (cylindrical shape or the like).
[0006]
The present invention has been made in view of such problems, and provides a drain member and a method for producing the same that have sufficient strength and can secure sufficient voids even when recycled products are used as raw materials. The purpose is to do.
[0007]
[Means for Solving the Problems]
A drain member according to the present invention is a drain member formed by welding a plurality of string-like materials obtained by extruding a fluid regenerated raw material at their mutual contact points and formed into a predetermined shape as a whole. 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 can be a recycled polypropylene product.
[0009]
Further, the method for producing a drain member according to the present invention includes charging a regenerated raw material into an extrusion container in which a plurality of extrusion holes are formed at a plurality of concentric positions on the extrusion surface, and the regenerated raw material from the extrusion hole. In the method for manufacturing a drain member in which a plurality of string-like extruded materials obtained are welded at their mutual contact points and formed into a predetermined shape as a whole, the extrusion holes are arranged in three equal positions on the same circle. The diameter of the extrusion hole is larger than the diameter of the extrusion hole at other positions.
[0010]
In this drain member manufacturing method, the recycled material can be a recycled polypropylene product.
[0011]
DETAILED DESCRIPTION OF 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 this embodiment is formed into a cylindrical shape as a whole by tangling a large number of string-like extruded materials 1, 1a and fusing them together at their contact points.
[0012]
Of the large number of string-like extruded materials 1 constituting the molded body, the material 1a extruded from the position of three equal circles centered on the cylindrical axis is larger in diameter than the other extruded materials 1. . The materials 1 and 1a are obtained by extruding a recycled product of a thermoplastic resin such as polypropylene.
[0013]
In the apparatus for manufacturing the drain member 1, an extrusion head 10 connected to an extruder main body (not shown) is disposed above a container 25 that stores 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 this flange. Further, 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 edge portion thereof and a hole provided in the flange portion of the head 10. Bolts 15 are inserted into the head 10, and the mold and the flange are fastened with nuts to fix the head 15 to the lower portion. A screw 20 is fixed at the center of the lower surface of the mold 12 with the longitudinal direction thereof being vertical, and a screw hole formed in the upper end portion of the support bar 21 is screwed to the screw 20 to thereby support the support bar. 21 is suspended from the center of the mold 12.
[0014]
Furthermore, a screw 22 is formed at the lower end of the support bar 21, and the core 23 is screwed into a screw hole formed in the upper half of the core 23, so that the core 23 is lowered at the lower end of the support bar 21. It is fixed to the part.
[0015]
A sheet-like band heater 11 is disposed on the outer surface of the head 10 so as to surround the head 10. The band heater 11 heats the extruded material in the head 10.
[0016]
A cylindrical receiving portion 24 is provided at the center of the water storage container 25 so as to surround the core 23. 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 24 a, 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 is bent, and is drawn to the outside from an outlet 27 provided on a side portion 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, copper alloy, or brass. If a material having low thermal conductivity such as stainless steel is used as the receiving part 24 and the core 23, a high-temperature extruded material may adhere to the receiving part 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 thereof. Only the small holes 13 are formed at equal intervals on the innermost arc and the outermost arc. On the other hand, large holes 14 are formed in three equally spaced positions on the central arc, and a plurality of small holes 14 are formed at equal 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. Further, the number of large holes 14 is three as described above, but the number of small holes 13 is, for example, 48 in total on three rows of circles.
[0018]
Next, a method for manufacturing the drain member of the present embodiment using the thus configured extrusion apparatus will be described. A recycled product obtained by recycling a waste material of thermoplastic resin such as polypropylene is inserted into an extruder main body, heated to a predetermined temperature and pressed. The regenerated extruded material 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. In the case of a novel product, the extrusion temperature is usually 250 ° C., and in the case of a recycled product, the temperature is slightly lower.
[0019]
Then, as shown in FIG. 4, the extruded materials 18 and 19 each having a string shape or a planar shape are extruded from the small hole 13 and the large hole 14 of the mold 12. The materials 18 and 19 are collected by the inclined portion 24 a 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 come into contact with each other and are fused at the 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 molded body is obtained in which string-like or planar extruded materials 18 and 19 are entangled with each other and formed into a cylindrical shape as a whole. The molded body is further cooled in water, bent in the lateral direction in the container 25, pulled out from the outlet 27, and cut into a predetermined length. The pulling 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 extruding holes of the mold 12 are provided with three large holes 14 having a diameter larger than that of the small holes 13 (positions with 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 are included in the extruded materials 18 extruded from a large number (for example, 48) of the small holes 13. By providing such a core material, the strength of the molded body is remarkably increased.
[0021]
The material 19 extruded from the large hole 14 having an inner diameter of 3 mm is 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 the product. The diameter is 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, and can be set to 2 to 4 mm, for example. The inner diameter 13 is not limited to 1.6 mm, and can be set to 1.2 to 1.8 mm, for example. The number of large diameters 14 is three. When the number of the large diameters 14 is an even number such as 4, for example, the strength of the molded body is lower than that when the number is 3. By making the number of the large diameters 14 odd, the strength of the molded body is improved. However, increasing the number such as 5 or 7 is not preferable because the weight of the molded body increases. Therefore, the number of large diameters 14, that is, the number of large-diameter extruded materials 19 is three.
[0023]
In addition, this invention can be used not only for the drain member used for the liquefaction prevention construction method but for various fields that require a structure having a high porosity. For example, it can be used as a drainage material. That is, as a side ditch of a parking lot or the like, a ditch is dug in the ground, the drain members are arranged side by side in two or three rows, and these are stacked in three or four rows, and on top of the soil By providing a filter that blocks the passage of water and forming a ground on the filter, rainwater passes through the drain member and is drained into the ground, allowing water to accumulate on the ground of the parking lot. Can be prevented. Thereby, the drainage property of a parking lot etc. can be improved. Moreover, soil can also be improved by using the drain member of this invention as an underground drainage material. Further, by immersing the drain member of the present invention in water such as a reservoir, a water purification action can be obtained and the water quality can be improved. Furthermore, the present invention can be used as a foundation for attaching a biofilm to sewage, factory wastewater treatment, etc., and bringing it into contact with sewage and factory wastewater. Therefore, the drain member of the present invention is also effective as a member that can obtain a large contact area with the liquid or gas.
[0024]
【Example】
Next, the effect of the embodiment that falls within the scope of the present invention will be described in comparison with a comparative example that is out of the scope of the present invention. A cylindrical molded body having an outer diameter of 100 mm and a length of 200 mm was formed by the method of the present invention and the conventional method (without large holes). In the embodiment, the large diameter is 3.0 mm, the small diameter is 1.6 mm, the number of large diameters is 3, and the number of small diameters is 48. In the comparative example, the inner diameter is 1.6 mm and the number is 54 pieces.
[0025]
At this time, the mass of the molded product was 950 to 1100 g / m per meter 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, whereas it was 700 to 800 mm / min in the case of the comparative example. Further, the defective rate was 3 to 4% in the example, whereas it was 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, in the vertical direction (cylindrical axial direction), the maximum compression load was 1.80 kN in the example, 1.68 kN in the comparative example, and horizontal. Regarding the direction (the 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 rate was 0.2 kN per second.
[0026]
Therefore, according to the present invention, a molded article having high strength (particularly, compressive load) can be obtained, and a drain material having a light mass of the molded article can be obtained. In the present invention, the productivity is high and the defective product generation rate is low.
[0027]
【The invention's effect】
As described above in detail, according to the present invention, in a molded body formed by entwining a string-like extruded material, three of the extruded materials are made thicker than the other extruded materials, and the molded body This thick extruded material was extruded from three equal 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 raw material for extrusion, it was molded. It is possible to ensure that the body strength is equal to or higher than that when using a new product. Therefore, the present invention increases the utility value of recycled products and makes a great contribution to the formation of a recycling 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 an embodiment of the present invention.
FIG. 3 is a plan view showing the same mold.
FIG. 4 is a perspective view showing the extruded state in the same manner.
FIG. 5 is a diagram showing a liquefaction prevention method.
FIGS. 6A to 6F are views showing the liquefaction prevention method in the order of steps.
[Explanation of symbols]
10: Header 12: Mold 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 welding a plurality of string-like materials obtained by extruding a fluid recycled raw material at their mutual contact points and molded into a predetermined shape as a whole, from three equally spaced points on the same circle The drain member, wherein the extruded string-like material is thicker than other string-like materials. The drain member according to claim 1, wherein the recycled material is a recycled product of polypropylene. A plurality of string-like extruded materials obtained by inserting a recycled material into an extrusion container having a plurality of extrusion holes formed at a plurality of concentric positions on the extrusion surface and extruding the recycled material from the extrusion holes. In the method for manufacturing a drain member, in which the extrusion holes are formed in a predetermined shape as a whole by welding at the mutual contact points, the diameters of the extrusion holes at three equal positions on the same circle are the extrusion holes at other positions. A method for producing a drain member, wherein the drain member is larger than the diameter of the drain member. The method for producing a drain member according to claim 3, wherein the recycled material is a recycled polypropylene product.

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