JPH07276387A - Production of composite paving material - Google Patents

Abstract

PURPOSE:To supply a kneaded material into a mold without a space by a method wherein a kneaded material of an aggregate with a melt plastic continuously discharged is preformed into a plate of a width slightly larger than the inner dimension of the mold, the plate is blanked into the same shape as the inner shape of the mold, and the blanked plate is put in the mold to be pressurized. CONSTITUTION:A kneaded material is supplied to a calendering roll to be calendered into a plate having a predetermined thickness and a width slightly larger than the inner dimension of a mold. The planar material is continuously supplied to a large-size press and blanked into the inner shape of the mold by a blade. Next, the blanked planar material (a first layer) is supplied to the mold one by one to be placed and again pressurized in the mold. Therefore, the planar material can be supplied to all the corners of the mold.

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 composite paving material used as a paving material for a surface in a sidewalk portion of a paved road, a park, a garden at the entrance, or the like.

[0002]

The applicant of the present application has previously proposed a composite paving material having sufficient strength and water permeability as the composite paving material. Its construction consists of a first layer and a second layer which is adhered to this layer via a thin primer or adhesive layer, said first layer crushing the aggregate to obtain its particle size. Is obtained by melting and molding 90 to 75% by weight of a pulverized product of 2 mm or more and 10 mm or less and 10 to 25% by weight of thermoplastic waste plastic. The second layer has a particle size of 1 mm or more and 5 mm or less. Some waste rubber particles 95-85% by weight and urethane resin 5
It is obtained by heat-curing after mixing and molding 15% by weight.

Therefore, when molding the first layer, as a method for discharging the kneaded product of the aggregate and the thermoplastic molten plastic, a single-screw conveyor is used to rotate the screw according to the amount of the material supplied to the outside of the machine. The kneaded product is fed to a mold by measuring a fixed amount with a measuring device.

[0004]

However, in this method, since the single screw is non-uniformly discharged during the measurement of the mold input amount, the supply amount of the kneaded product of the aggregate and the thermoplastic molten plastic is Variation is large and it is difficult to measure a certain amount. In the product of the composite pavement material, it is important in terms of quality to make the thickness uniform, but in the above-mentioned conventional technology, the yield of non-defective products cannot be improved because it is difficult to measure a certain amount, which is a bottleneck in the process. . In addition, due to the unstable amount of the kneaded product of the aggregate of the first layer and the thermoplastic molten plastic, the composite paving material has poor appearance, unstable strength, and unstable water permeability. Has become. Further, the kneaded product supplied into the mold by the single screw conveyor becomes a heap in the mold and does not naturally spread to every corner of the mold. Therefore, an attempt was made to make the thickness uniform with a press of about 100 Ton / m ² , but this uniformization is difficult. Therefore, at present, it is the actual situation that the above-mentioned kneaded product, which has been piled up in a mold, is forced to be evenly forced by a human and then subjected to a press to have a uniform thickness. At this time, the working environment is not always good, and automation from a machine is desired from the viewpoint of occupational safety and health.

Therefore, an object of the present invention is to stabilize the amount of the kneaded product of the aggregate of the first layer and the thermoplastic molten plastic, which is introduced into the mold, and there is no influence of the variation of the supply amount and the workability is improved. It is possible to obtain improved and stable quality products, it is possible to automate the feeding and flattening of the kneaded products into the mold, and as a composite paving material, the appearance, stability of strength, and water permeability are improved. It is to provide a method for manufacturing a composite pavement material.

[0006]

The feature of the present invention is that the step of melt kneading and molding a large amount of aggregate and a small amount of thermoplastic waste plastic to form the first layer is continuously discharged. The process of preforming a molten product of kneaded aggregate and waste plastic into a plate shape slightly wider than the inner dimension of the mold, and shaping the plate-shaped kneaded product into a shape that matches the internal shape of the mold. It is composed of a punching step and a step of installing a punched plate-shaped molten product in a mold.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, after the aggregate 1 and the thermoplastic waste plastic 2 are melted and kneaded 3, the melted product is continuously discharged by a uniaxial screw conveyer, and is then subjected to multistage rolls and / or presses. Pre-form 4 into a plate shape slightly wider than the inner dimension of the mold. After that, the plate-shaped kneaded product is punched 5 according to the internal shape of the mold. As a result, the first layer is formed, and the first layer is placed and pressed in the mold 6. Then, a thin primer or adhesive 8 is applied 9 on the first layer. This application 9
May be before the insertion 7 of the first layer into the mold 6. Therefore, a mixture 12 of the particles of the waste rubber 10 which is the second layer and a small amount of the urethane resin 11 is cast on the first layer 13
Then, the surface is flattened and pressure 14 is applied. Further, the first and second layers that have been laminated are heated in the mold as a whole to be solidified by heating 15 and then cooled 16 and taken out from the mold by a process 17.

As the aggregate 1, any of pulverized materials of construction waste such as gravel, crushed stone, and concrete waste may be used, or a mixture thereof may be used. The particle size of these aggregates 1 is usually 2 mm in order to satisfy both strength and water permeability.
It is from 10 mm, preferably from 2.5 mm to 7.0 mm.

The waste plastic 2 is thermoplastic and may be any kind of waste plastic as long as it has a certain affinity for the aggregate 1. However, normally, a relatively large amount of waste plastic or recycled plastic is used. Wastes of so-called general-purpose plastics such as low-density polyethylene, high-density polyethylene, polypropylene, polystyrene, polyethylene terephthalate, EVA resin, polyvinyl chloride, etc. that are in circulation are used. Especially polyethylenes,
Wastes of polypropylene, polyethylene terephthalate, and polystyrene are preferable in terms of the balance between processing workability and product properties. These waste plastics 2 may be used in a single kind, or may be used in combination. Particularly, when waste polystyrene is used as a base, physical properties of the product (brittleness) may be obtained by using waste polyethylene together. It is better to improve.

The first layer is made by kneading a large amount of aggregate 1 and a small amount of molten waste plastic 2, and in order to give water permeability when mixing the aggregate 1 and the waste plastic 2, a large amount is required. The mixing ratio is selected so that a relatively small amount of waste plastic 2 is added to the aggregate 1. This is because if the aggregate 1 is too much, the strength of the product as a pavement material will be insufficient, and conversely, if this aggregate is too small, the amount of the waste plastic 2 will be relatively large and the water permeability will be impaired. Because. Therefore, for example, the aggregate 1 is 90 to 75% by weight, and the mixing ratio of the waste plastic 2 is 10 to 25% by weight.
It is a degree.

The method for continuously kneading a large amount of aggregate 1 with a relatively small amount of waste plastic 2 is not limited to the above-mentioned uniaxial screw conveyor, but different direction twin screw conveyor, different direction biaxial-single screw. Various methods such as axial tandem extrusion are possible.

As a method for densely filling the mold 6 with the kneaded product of the aggregate 1 and the waste plastic 2 which are continuously discharged in this way, the plate-shaped 4 is preliminarily molded. Specifically, first, the kneaded product is supplied to a rolling roll and rolled to form a plate-like member 4 having a predetermined thickness and slightly wider than the inner dimension of the mold. This plate-like material 4 is continuously supplied to a large-sized press, and a step 5 of punching into an inner size shape of a die with a blade die is started. Next, the punched plate-shaped objects, that is, the first layers are supplied to the mold 6 one by one, and the pressure 7 is applied again in the mold. Therefore, the first layer spreads to every corner of the mold and forms a first layer having good strength and shape.

As a rolling means for forming 4 into a plate shape,
In addition to the rolling roll, a plate-like material can be formed by using a rolling press or a combination of a rolling roll and an endless belt.

The second layer is formed by mixing a large amount of waste rubber 10 and a small amount of urethane resin 11 and thermosetting.

As the waste rubber 10, waste materials of industrial materials such as automobile tires and conveyor belts are used, and it is waste tires that can be stably obtained in terms of quality and quantity. At this time, if the particle size of the pulverized waste rubber is too large, not only the appearance of the product is impaired, but also the resistance to abrasion and scratching becomes low. On the other hand, if the particle size is too small, it is easy to obtain a homogeneous one having high strength, but the water permeability is lost. Also, it is desirable that the particle diameters be as uniform as possible,
Those having a narrow particle size distribution are preferable. Desirable particle size is 1-5
mm.

As the urethane resin 11 used for solidifying the waste rubber particles 10, any commercially available product can be used as long as it has sufficient strength and elasticity, and it can be used as a one-component type or a two-component type. But good. Generally, it is selected in consideration of the strength of the obtained product and the workability in mixing and molding with the granular waste rubber 10. At this time, it goes without saying that pigments and various additives for coloring the product can be used together with the granular waste rubber.

If the amount of the urethane resin 11 applied to the particles of the waste rubber 10 is too small, the strength of the product will not be sufficient even after curing, and if it is too large, the strength as a paving material will be sufficiently high. The urethane resin 11 fills the gaps between the granular rubbers 10 and impairs the water permeability of the product. Therefore, for example, the mixing ratio of the waste rubber 10 is 95 to 85% by weight.
On the other hand, it is suitable that the mixing ratio of the urethane resin 11 is about 5 to 15% by weight.

The method for curing and molding the waste rubber particles 10 and the urethane resin 11 is only to heat them, but since they are usually heated 15 in the mold, they are put in a heating furnace or tunnel furnace together with the urethane and Cure the resin. In particular,
In the present invention, a mold obtained by molding a first layer made of aggregate 1 and waste plastic 2 is used as it is, and a mixture 12 of waste rubber 10 and urethane resin 11 is cast 13 on the upper part thereof. It is preferable that the second layer is formed by flattening and pressing 14 and then heating 15. Heat the whole mold 15
After sufficiently solidifying the second layer, the mold is cooled for 16 minutes or forcedly cooled to solidify the first layer containing the thermoplastic resin, and the first layer and the second layer are combined. By taking out 17, a composite paving material product 18 can be obtained.

At this time, since the thermoplastic plastic resin 2 of the first layer and the urethane resin 11 of the second layer do not necessarily have sufficient compatibility and adhesiveness, the adhesive force between both layers is increased. As a method, a primer or an adhesive 8 is applied 9 in a thin layer between both layers.

At this time, the primer or the adhesive 8
It is important that, even when used as a thin film, it exhibits sufficient adhesive strength and does not impede the water permeability of the entire product.

The contents of the present invention will be described more specifically by comparing the experimental examples with the comparative examples.

Experimental Example Crushed stone obtained by crushing granite and having a particle size of 2.5 mm
80% by weight of granular aggregate (No. 7 crushed stone) of ~ 5.0 mm was heated to about 250 ° C with a burner, and waste polystyrene 1
8% by weight and 2% by weight of waste polyethylene, 120φmm with 10mm clearance between screw and barrel
Melted and kneaded with a single screw and continuously discharged molten composite is fed to a 500φ two-stage rolling roll and rolled, and has a thickness of 25 mm, which is slightly wider than the inner dimension of the mold, 35 cm. The width is plate-shaped. This plate-like material is continuously supplied to a large-sized press and is punched with a blade die into the inner dimension of the die of 30 cm × 30 cm. Next, the punched plate-like objects were supplied to the mold one by one, and then the whole surface was pressed with a flat plate at about 7 Ton. Approximately 2.5 cm thick crushed stone obtained as above
On the surface of the waste plastic composite, about 1 g of an adhesive (Aqua Coat Adhesive SU, Komatsu Synthetic Resin Co., Ltd.) diluted twice with methanol was spray-coated.

Then, 88% by weight of waste rubber particles having a particle diameter of 2 mm to 3 mm and a one-component urethane resin (Aqua Coat U-110, which had been separately mixed in a batch mixer, were further added thereto.
0B, Komatsu Synthetic Resins Co., Ltd.) 9% by weight, red pigment (B
ayferrox 110M, Bayer Japan Ltd.) 0.9 kg of a 3% by weight mixture was injected. This was capped with an inner lid, pressurized for about 1 Ton, continuously moved in a tunnel type heating furnace having an ambient temperature of 200 ° C. for about 10 minutes, and then naturally cooled in the air for about 10 minutes. A 30 cm × 30 cm square composite pavement having a red second layer 1.3 cm on top of the first layer 2.5 cm was obtained.

This product has a good appearance as a paving material,
A product having sufficient strength and water permeability and stable quality was obtained with a good yield by the continuous production method. In addition, there is no effect of variation in the supply amount, the mixture spreads to every corner of the mold, and manual work such as smoothing with an iron spatula is not required, which improves workability.

Comparative Example The molten composite discharged was supplied to a rolling roll and rolled to have a thickness of 25 mm, which was slightly wider than the inner dimension of the mold.
Formed into a plate with a width of 5 cm, this plate was continuously fed to a large-scale press, punched into 30 cm x 30 cm internal dimensions of the die with a blade die, and the portion fed to the die one by one was discharged. A composite paving material was obtained in the same manner as in Experimental Example 1, except that 3.3 kg of the molten composite thus obtained was weighed by a measuring device and injected into a mold.
In this product, the mixture did not reach every corner of the mold, the appearance of the corners of the product was poor, and although the product had good strength and water permeability, a product with good appearance could not be obtained with good yield by the continuous production method.

[0027]

EFFECTS OF THE INVENTION According to the present invention, it is possible to continuously manufacture a composite pavement material by automatically supplying and kneading a kneaded product to a mold, and to supply the kneaded product to the mold without a gap. Therefore, there is no influence of variations in the supply amount, and workability is improved. Furthermore, the composite pavement material produced according to the present invention has a good appearance, has sufficient strength, has good water permeability, is of stable quality, and further has a thermoplastic waste plastic or a waste rubber, and further a concrete waste material. Since such waste is used, it is also effective as a means for reusing waste.

[Brief description of drawings]

FIG. 1 is a block diagram showing a process of the present invention.

[Explanation of symbols]

 1 Aggregate 2 Waste plastic 3 Melt-kneading process 4 Plate-forming process 5 Punching process 6 Mold 7 Pressing by inserting into mold 8 Adhesive or primer 9 Applying process 10 Waste rubber 11 Urethane resin 12 Mixing Process 13 Casting process 14 Flattening and pressurizing process 15 Heating process 16 Cooling process 17 Process of taking out from mold 18 Composite pavement product

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Claims (1)

[Claims] 1. A step of forming a first layer by melt-kneading and forming a large amount of aggregate and a small amount of thermoplastic waste plastic, and applying a thin primer or adhesive on the first layer. A step of laminating a second layer consisting of a mixture of a large amount of waste rubber particles and a small amount of polyurethane on the first layer, and the laminated first and second layers In the continuous manufacturing process of the composite paving material consisting of the step of heating and solidifying the whole inside, and then the step of cooling, the step of forming the first layer is the step of continuously discharging aggregate and melting. A step of preforming a kneaded product with waste plastic into a plate shape slightly wider than the inner dimension of the mold; a step of punching the plate-shaped kneaded product into a shape corresponding to the inner shape of the mold; The step of inserting the removed plate-shaped kneaded product into the mold Continuous process for producing a composite paving material, characterized.