JPH06286006A - Production of water-permeable synthetic resin block - Google Patents

Abstract

PURPOSE:To simply produce a water-permeable synthetic resin block by grinding a used synthetic resin foam material and reducing the volume of the ground particles by a heating or friction means and filling a mold with the volume loss particles to thermally fuse the volume loss particles by the heat remaining in the particles so as to leave the gaps between the particles. CONSTITUTION:The ground product sent to a ground product supply part is pushed in the gap between a fixed disc 9 and a rotary disc 10 to receive shearing stress between both discs rotating at a high speed and reduced in volume by frictional heat. The volume loss particles are forcibly discharged from the outer periphery gas between the rotary disc 9 and the fixed disc 10 by the centrifugal force of the rotary disc 9 and sucked in a blower 11 through the collection member arranged to the outer peripheries of both discs 9, 10. A block mold 15 is filled with the volume loss particles through the particle feed pipe 12 extending from the blower 11 and the volume loss particles are mutually thermally fused by the heat remaining in the volume loss particles so as to leave gaps to produce a water-permeable synthetic resin block.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a water-permeable synthetic resin block, and more particularly to a method for producing a water-permeable synthetic resin block used as a culvert material or a drainage material buried in soil. The present invention also relates to a method for producing a water-permeable synthetic resin block that can contribute to effective use of resources by utilizing a used synthetic resin foam material that is industrial waste.

[0002]

2. Description of the Related Art As a method for producing a water-permeable synthetic resin block used as an underdrain material or a drainage material, many methods have hitherto been proposed. For example, as described in JP-A-4-153026, foamed particles having a closed cell structure and a polyolefin resin aqueous dispersion having a melting point of 40 to 90 ° C. are mixed, and then the mixture is placed in a molding die. Filling and heating to a temperature below the softening point of the foamed resin to disperse the water content of the aqueous dispersion, melt the polyolefin-based resin, and then cool and solidify the foamed resin particles to adhere to each other. A method of manufacturing a foam block by the method is disclosed.

Further, in Japanese Unexamined Patent Publication (Kokai) No. 52-140569, when a polystyrene foam particle is transferred from a hopper into a mold having air permeability by a screw feeder, a liquid adhesive is put into the outlet of the hopper or the screw feeder. The particles are mixed with the adhesive while the polystyrene foam particles are fed and the expanded polystyrene particles are transferred by the rotation of a screw feeder, the mixture is filled in the mold, and then the adhesive is dried by hot air. Disclosed is a method for producing an expanded polystyrene molded product having continuous pores by solidifying and adhering expanded polystyrenes to each other.

Each of the above methods is characterized in that a polyolefin resin or an adhesive is used for adhering the expanded resin particles to each other. In other words, the common feature is that the binder is interposed to adhere the expanded resin particles to each other.

[0005]

According to the above-mentioned prior art, a liquid adhesive as a binder is required and a step of mixing and a step of drying and solidifying the adhesive with hot air are required. In view of the above technical problems, an object of the present invention is to provide a method for manufacturing a water-permeable synthetic resin block that does not use a binder such as an adhesive and has a simple manufacturing process. At the same time, it is also an object to provide a method for effectively utilizing a used synthetic resin foam material, which has become a social problem in recent years.

[0006]

The present inventor has accomplished the present invention as a result of intensive research to solve the above problems. That is, the gist of the present invention is to pulverize a used synthetic resin foam material and reduce the volume of the volume-reduced particles by a heating means or a friction means. It is a method for producing a water-permeable synthetic resin block, which is characterized in that heat fusion is performed in the state of being left.

Further, according to the present invention, the friction means is composed of a pair of disc bodies in which the surfaces having the concavo-convex portions are opposed to each other and are spaced apart, and one disc body is fixed and the other disc body is rotated, It is a means for reducing the volume of the synthetic resin foam material between the disc bodies. Further, the present invention is a means in which the heating means or the friction means is an extruder having a screw in a barrel.

Various materials can be used as the used synthetic resin foam material used in the present invention. For example, polystyrene resin foam molded products, polystyrene-based styrene copolymer resin foam molded products, or mixtures thereof, polyethylene resin foam molded products, polypropylene resin foam molded products, packing materials for home appliances, fish, etc. Examples include recovered items used in boxes and various food trays.

As a means for crushing the used synthetic resin foam material and reducing the volume by heating or friction, a heating means and a friction means may be used in combination, and known means can be used (Japanese Patent Publication No. 54-12512). Japanese Patent Publication No. 60-6205, Japanese Patent Publication No. 60-8205, Japanese Patent Publication No. 60-266
No. 87). The degree of volume reduction can be appropriately adjusted according to the purpose of use. For example, from the degree of melting the minimum necessary surface area sufficient to bond the crushed particles to the degree of completely defoaming and turning into resin,
It can be adjusted freely.

[0010]

According to the method for producing a water-permeable synthetic resin block of the present invention having the above structure, when the volume of the used synthetic resin foam material is reduced by the heating means or the friction means, the heat remaining in the volume-reduced particles is utilized. Since the volume-reduced particles are heat-sealed with a gap left between them, a binder such as an adhesive need not be used, and an extra step for drying the adhesive can be omitted. Moreover, since the used synthetic resin foam material is used, it is extremely resource-saving.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a manufacturing apparatus used in the method of manufacturing a water-permeable synthetic resin block according to the present invention. Reference numeral 1 denotes a crushing means, which is composed of a plurality of crushing blades, and the crushing blade is composed of a cylindrical tubular body and a plurality of saw blades which are attached around the cylindrical body at regular intervals. Are arranged so that they overlap each other. The crushing blade is driven by the motor 4. A screen 2 is provided around the sides and bottom of the crushing blade.
The screen 2 is a screen having a rough opening such as a porous punching metal or a mesh wire mesh, and the size of the opening is appropriately selected in consideration of the physical properties of the foam to be crushed and the like. A hopper 3 whose lower part is inclined like a funnel is installed so as to include the crushing means 1 and the screen 2. A screw conveyor 6 is arranged below the hopper 3, and the feed amount of the crushed product to the volume reducing unit described later is adjusted by adjusting the screw rotation speed of the screw conveyor 6.

The screw conveyor 6 sends the crushed product to the volume reducing section. The volume reducing section is composed of a crushed product supply section, a fixed disk body 10 supported oppositely, and a rotating disk body 9 rotating at a high speed. At the center of the outer surface of the rotating disk body 9, a rotating shaft supported by a bearing is attached.
It is installed so as to be rotationally driven by the drive from the motor 8. On the other hand, a screw 7 is screwed into the center of the inner surface of the rotating disk body so as to penetrate through the central opening of the fixed disk body 10, and is configured to follow the rotational drive of the rotating disk body 9. On the other hand, the fixed disk body 10 is welded to the end portion of the casing that covers the outer surface of the screw 7. Then, on the inner surface sides of the rotating disk body 9 and the fixed disk body 10 facing each other,
Concavo-convex portions are formed and are arranged with an interval of about 1.0 mm.

The crushed product sent to the crushed product supply section is pushed into the gap between the fixed disk body 10 and the rotating disk body 9 by the screw 7. The crushed product is subjected to shear stress between the rotating disk body 9 and the fixed disk body 10 which rotate at high speed, and is reduced in volume by frictional heat. The volume-reduced particles whose volume has been reduced are forcibly discharged from the outer peripheral gap between the rotating disk body 9 and the fixed disk body 10 by the centrifugal force of the rotating disk body 9. The discharged volume-reduced particles are sucked into the blower 11 via a collecting member (not shown) installed on the outer circumference of the rotating disk body 9 and the fixed disk body 10.

Then, the volume-reduced particles are passed through the granulating tube 12 extended from the blower 11 to the block forming die 15
To produce a water-permeable synthetic resin block by heat-sealing the volume-reducing particles to each other while leaving a gap while the volume-reducing particles are not cooled, that is, by the heat remaining in the volume-reducing particles. . Of course, at this time, blower 1
It is also possible to directly fill the block mold 15 from 1. Further, if the volume-reduced particles may be cooled during the particle transfer due to the long distance of the particle transfer tube 12 from the blower 11 to the block molding die 15, the ribbon heater 13 is attached to the particle transfer tube 12.
A heating means such as the above may be provided to heat and keep the particle feeding tube 12 warm. Further, it is preferable to install a dispersion plate 14 in the lower part of the outlet of the granulating tube in order to uniformly fill the block molding die 15 with the volume-reduced particles.

FIG. 2 is a schematic configuration diagram showing another embodiment of the manufacturing apparatus used in the method of manufacturing the water-permeable synthetic resin block according to the present invention. 21 is a crusher, and the crusher 21
A pair of crushing blades 2 that rotate in opposite directions are provided on the upper part of the
2 and 22 are mounted, and the crushing blades 22 and 22 are rotationally driven by a driving force from a motor (not shown) via a pulley (not shown). A screen 29 is provided on the side surface and the bottom surface of the crushing blades 22, 22. The screen 29 is a screen having a rough opening such as a porous punching metal or a mesh wire mesh, and the size of the opening is appropriately selected in consideration of the physical properties of the foam to be crushed.

The reference numeral 23 designates the foam crushed by the crusher 21,
This is a granulation pipe for sending the air by a blower or the like to a hopper attached to the upper part of the extruder. Reference numeral 24 is an inverted quadrangular pyramid-shaped hopper provided on the upper end of the rear end of the extruder. The foam that has been crushed to an appropriate size by the crusher 21 is used as the granulating tube 2
3, the air is supplied to the hopper 24 attached to the extruder 25 by means of a blower or the like.

Reference numeral 25 is an extruder having a screw which is rotationally driven by a driving force of a motor in a cylindrical barrel, and it is preferable to provide a heating means such as a heater (not shown) on the outer periphery of the barrel. A die (not shown) having a plurality of nozzle holes is installed at the tip of the extruder 25. A rotary cutter 26, which is rotationally driven by a motor 30, is arranged on the front surface of the mold so that the strand-shaped volume-reduced product can be cut. The rotary cutter 26
For, the volume-reduced strand-shaped volume-reduced product is cut into particles of an appropriate size.

Reference numeral 27 is a block molding die for forming the water-permeable synthetic resin block into a desired shape. 28 is a volume-reduced particle that has been reduced in volume and cut. Example 1 An apparatus for producing a water-permeable synthetic resin block using a foamed polystyrene bead molding (specific gravity 0.02) used for a home electric appliance packaging material as a used synthetic resin foaming material is shown in FIG. The equipment shown was used. As the block forming die, a die having a size of 1 meter in each length and 1.5 meters in height was used. A ribbon heater was attached around the granulation tube, and the temperature of the granulation tube was set to 70 ° C. Further, a conical dispersion plate having a diameter of 0.4 m was attached to the lower part of the outlet of the granulating tube. The screen below the crushing blade had a hole diameter of 10 mm. The pulverized product pulverized by the pulverizing means was amorphous particles having a maximum diameter of less than 10 mm, and its bulk specific gravity was about 0.01.

The gap between the fixed disk body and the rotating disk body is 0.9 m.
m, the rotary disk was rotated at 1,500 rpm, and the volume of the crushed product was reduced by 17 kg per hour. The crushed product, which is discharged as filaments containing air from the gap between the fixed disk and the rotating disk, has an average particle size of 5
The volume was reduced to mm of popcorn-like amorphous particles. Then, the volume-reduced particles are filled in a block molding die by gravity fall, and then naturally cooled to have a bulk specific gravity of 0.
Twenty-five water permeable synthetic resin blocks were manufactured. The water permeable block had a whirlpool shape in which the surfaces of the particles were point-bonded to each other.

Example 2 An apparatus for producing a water-permeable synthetic resin block using a foamed polystyrene food tray (specific gravity 0.05) collected by a consumer organization as a used synthetic resin foam material, The apparatus shown in FIG. 1 was used. As the block forming die, a die having a size of 1 meter in each length and 0.5 meter in height was used. However, the granulating tube was not used, and the block mold was directly filled from the blower. As the screen below the crushing blade, a wire mesh with an opening of 20 mm was used. The crushed product crushed by the crushing means was a chip-like product having a thickness of about 1 to 6 mm and a longest diameter of 20 mm or less, and its bulk specific gravity was about 0.03. The gap between the fixed disk and the rotating disk is set to 0.9mm, and the rotating disk is 1,500 rpm.
The pulverized product was volume-reduced at an amount of 17 Kg per hour to reduce the volume into popcorn-like amorphous particles having an average particle diameter of 10 mm, and the true specific gravity was lowered to about 0.6. Then, the volume-reduced particles are filled in a block molding die by gravity fall, and then naturally cooled to have a bulk specific gravity of 0.
35 water-permeable synthetic resin blocks were produced. The water permeable block had a whirlpool shape in which the surfaces of the particles were point-bonded to each other. The water permeability of the water permeable synthetic resin block was 5 cm / sec. The water permeability was based on the constant water level water permeability test method JIS-A1218. The porosity of this water permeable block was about 40%.

Example 3 As the used synthetic resin foam material, an expanded polystyrene bead molded product (specific gravity 0.02) used for packaging materials for home electric appliances was used. The apparatus shown in FIG. 2 was used as the apparatus for producing the water-permeable synthetic resin block. As the block molding die, a die having a size of 0.5 meters in length and width and 0.5 meter in height was used. The screen is 20 mm wide
Used wire mesh.

The molded product was crushed with a crusher. The pulverized product was powdery to amorphous particles having a longest diameter of less than 20 mm, and its bulk specific gravity was about 0.01. The crushed product is supplied from the hopper to the extruder, and the extrusion rate is 30 Kg / Hr.
The volume was reduced. Extruder barrel 1 by heater
Heated to 80 ° C. Then, it is extruded from a mold having a plurality of nozzle holes attached to the tip of the extruder and cut by a rotary cutter to have an average diameter of about 10 mm and a length of about 10 m.
A cylindrical volume-reduced product of m was obtained. The cylindrical volume-reduced product has been rounded by surface tension until cooled. The true specific gravity of the reduced volume product was about 0.8. (It can be about 0.6 depending on the melting conditions.) Then, the volume-reduced particles are filled into the block forming die by natural dropping, and then naturally cooled, so that the bulk specific gravity becomes 0 as shown in FIG. A water-permeable synthetic resin block of No. 4 was manufactured. The water permeable block had a whirlpool shape in which the surfaces of the particles were point-bonded to each other. The water permeability of the water permeable synthetic resin block is 8 cm / s.
It was ec. Permeability coefficient is a constant level permeability test method JIS-
According to A1218. The porosity of the water permeable block was 40%.

[0023]

As is apparent from the above description, according to the method for producing a water-permeable synthetic resin block of the present invention, when the volume of the used synthetic resin foam material is reduced by the heating means and / or the friction means, , The heat of the volume-reducing particles is used to heat-bond the volume-reducing particles to each other with a gap left between them, so it is not necessary to use a binder such as an adhesive, and as a result, the adhesive is dried. It is possible to omit an extra step for doing so. Therefore, it is very easy to manufacture.

Moreover, since the used synthetic resin foam material, which has become an environmental problem, is used, there is a great effect from the viewpoint of effective utilization of resources. Further, as the heating means or the friction means, it is sufficient to use an existing volume reducer, an extruder or the like which has been conventionally known, so that there is an effect that the manufacturing cost is low.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a manufacturing apparatus used for a method of manufacturing a water-permeable synthetic resin block according to the present invention.

FIG. 2 is a schematic configuration diagram showing another embodiment of the manufacturing apparatus used in the method of manufacturing the water-permeable synthetic resin block according to the present invention.

FIG. 3 is an example of a water-permeable synthetic resin block manufactured by the method of manufacturing a water-permeable synthetic resin block according to the present invention.

[Explanation of symbols]

 1 crushing means 2 screen 3 hopper 4 motor 5 motor 6 screw conveyor 7 screw 8 motor 9 rotating disk body 10 fixed disk body 11 blower 12 granulation tube 13 ribbon heater 14 dispersion plate 15 block molding mold 16 water-permeable synthetic resin block 21 crushing Machine 22 Crushing blade 23 Grain feeding pipe 24 Hopper 25 Extruder 26 Rotary cutter 27 Block forming die 28 Volume-reducing particles 29 Screen 30 Motor

Claims (3)

[Claims] 1. A used synthetic resin foam material is crushed and volume-reduced particles whose volume is reduced by a heating means or a friction means are filled in a molding die, and the volume-reduced particles are separated from each other by the heat remaining in the volume-reduced particles. A method of manufacturing a water-permeable synthetic resin block, which comprises heat-sealing with a gap left. 2. The friction means is composed of a pair of disc bodies with surfaces having concave and convex portions facing each other and spaced from each other, and one disc body is fixed and the other disc body is rotated, whereby the disc body is rotated. The method for producing a water-permeable synthetic resin block according to claim 1, characterized in that the volume of the synthetic resin foam material is reduced. 3. The method for producing a water-permeable synthetic resin block according to claim 1, wherein the heating means or the friction means is an extruder having a screw in the barrel.