JP7627794B1 - Artificial turf structure and method for laying it, and ground using the same - Google Patents

Abstract

[Problem] An artificial turf structure is constructed using a filler made of natural material that does not float on water. [Solution] An artificial turf structure 1 in which filler 5 is filled between the piles 4 of the artificial turf, said filler 5 containing a wood material, characterized in that the bulk density of this wood material in its total dry state is 0.2 g/cm3 or more. The wood material with the above-mentioned set bulk density value is formed by compressing the material itself once, and the compression reduces the porosity within the wood material, reducing the number of air spaces, making it less likely to float on water. [Selected Figure] Figure 1

Description

The present invention relates to an artificial turf structure that can be laid on the grounds of soccer, baseball, and other ball fields, sports stadiums, and other facilities to create fields suitable for athletic competitions.

Grounds covered with artificial turf are easier to construct and maintain than natural grass fields, and can be used regardless of the weather, so they are used for a variety of ball game fields, such as futsal fields and baseball outfields.

Artificial turf ball game fields are constructed by filling the pile of the artificial turf with granular elastic filler, silica sand, or the like in order to reduce the impact and frictional resistance experienced by athletes when they run, fall, or slide on the artificial turf.
Currently, crushed waste rubber products such as waste tires, and rubber chips made from SBR (styrene butadiene rubber) and EPDM (ethylene propylene diene rubber) are widely used as fillers for filling the piles of artificial turf (see, for example, Patent Document 1).

JP 2003-34906 A

Recently, marine plastic and microplastic issues have come into the spotlight, and from an environmental protection perspective, various business sectors are refraining from using plastic products and considering using natural products instead. In artificial turf, it is being considered to replace the rubber infill with natural infill, and for example, attempts are being made to mix materials made from coconut shells, coconut fiber, cork, and other trees cut up and the bark tissue peeled off to use as infill.

However, although the tree-based infill can provide cushioning to the artificial turf, when there is heavy rainfall and water accumulates within the artificial turf, the infill can float through the gaps in the piles of the artificial turf and flow out of the field on which the artificial turf is laid.

If the infill material flows out, the artificial turf loses its cushioning properties, which reduces the performance of the athletes playing on it and makes them more susceptible to injury. In addition, infill material that flows outside the field can cause blockages in the facility's drainage channels, and if it flows onto the track or court of a sports stadium, it can interfere with the game, so the infill material must be collected immediately. Although there has been consideration of using natural materials as infill material for artificial turf, the reality is that no suitable substitutes for the rubber infill material are being used.

In view of the problems inherent in conventional technology, the present invention aims to construct an artificial turf structure using a filler made of natural materials that does not float on water.

In order to solve the above problems, the present invention includes the following aspects.
[1] An artificial turf structure in which infill material is filled between the piles of the artificial turf,
The filler contains a wood material,
An artificial turf structure, characterized in that the wood material has a bulk density in a total dry state of 0.2 g/cm3 or ^more .
[2] The artificial turf structure according to [1], wherein the porosity of the wood material is 80% or less.
[3] The artificial turf structure according to [1] or [2], wherein the wood material has a pore volume of 4.0 cm ³ /g or less.
[4] The artificial turf structure according to any one of [1] to [3], wherein the average pore diameter of the wood material is 1.0 μm or less.
[5] The artificial turf structure according to any one of [1] to [4], wherein the wood material is obtained by soaking wood pellets in water and dissolving them.
[6] The artificial turf structure according to any one of [1] to [5], wherein the pile of the artificial turf is a crimped pile.
[7] The filler layer, which is the portion filled with the filler, is composed of at least two layers,
The filler of the top layer of the filler layer contains a wood material;
The artificial turf structure according to any one of claims 1 to 6, wherein the filler in the layer below contains silica sand.
[8] The infill layer, which is the portion filled with the infill material, is formed by mixing silica sand and a infill material containing a wood material. The artificial turf structure according to any one of [1] to [6].
[9] The artificial turf structure according to any one of [1] to [8], wherein the artificial turf is provided on a cushioning layer.
[10] A step of laying artificial turf;
A wood pellet scattering step of scattering wood pellets on the artificial turf;
a wood pellet burying step of burying the scattered wood pellets between piles of the artificial turf;
a watering process in which water is sprayed onto the buried wood pellets to allow them to absorb water;
A wood pellet disintegration process for disintegrating the wood pellets that have absorbed water;
A method of laying an artificial turf structure comprising:
[11] A step of laying artificial turf;
A step of soaking the wood pellets in water to absorb the water;
A step of thawing the wood pellets that have absorbed water;
filling the gaps between the piles of the artificial turf with the decomposed wood pellets;
A method of laying an artificial turf structure comprising:
[12] A ball game ground constructed using the artificial turf structure according to any one of [1] to [9] above.
[13] A teeing ground constructed using the artificial turf structure described in any one of [1] to [9] above.

As mentioned above, wood chips, which are made by finely cutting wood or its bark, can be used as infill to provide artificial turf with a moderate amount of cushioning, but they have the problem of floating on water and being prone to being washed away.
It is generally known that the true density of wood, excluding voids, is about 1.5, regardless of the species of wood. It is presumed that wood with this specific gravity floats on water because of the buoyancy caused by air bubbles trapped in the tracheids within the wood, as well as because the hydrophobic substance lignin contained in the wood acts to prevent the absorption of water.

To prevent buoyancy from acting, wood can be compressed to crush the fibers and process it so that air does not accumulate inside the wood, making it difficult for air to be retained in the wood. Also, even if the bulk density is less than 1.0, if the wood has hydrophilic properties, it can absorb water and become buoyant. As shown in the examples below, it has been confirmed that compressing wood chips to increase their bulk density increases the water absorption of the wood chips, allowing the wood chips to settle in water. This is presumably due to the fact that in the process of compressing the wood chips, the lignin in the wood acts as an adhesive during compression and is consumed and reduced, which increases the hydrophilicity of the wood chips, and also due to the effect of capillary action caused by the porosity and pore size decreasing when the inside of the wood is crushed.

As described above, the artificial turf structure of the present invention is characterized in that the spaces between the piles of the artificial turf are filled with filler, the filler contains compressed wood material, and the bulk density of the wood material in its total dry state is 0.2 g/ ^cm3 or more.
The filler is made of wood material made of natural materials, for example wood chips made by cutting wood and its bark into small pieces, and by compressing and processing the wood chips to crush the fibers, the wood chips that are released from the compressed state and spread out have a higher bulk density than before compression and also have higher water absorption, so that even if water accumulates on the artificial turf due to rainfall, they do not float up but sink into the water and remain within the artificial turf, and do not flow out of the field on which the artificial turf is laid, and can exhibit the same cushioning properties as conventionally used natural fillers. In addition to wood materials, the filler may also contain granular materials such as silica sand and other materials.
In addition, the filler made from the wood material has a brown, warm color, or white surface, which makes it less susceptible to heat absorption than black rubber chips, preventing the surface temperature of the artificial turf from rising on sunny days.In addition, because it is porous, it easily absorbs water, so it is possible to prevent the surface temperature of the artificial turf from rising during the day by spraying water on the artificial turf and having the filler absorb and store the water.

In the artificial turf structure having the above configuration, it is preferable that the porosity of the wood material that constitutes the infill is 80% or less. If the wood material has a porosity of 80% or less, it is difficult for air to be retained within the material, making it difficult for it to float on water.

It is preferable that the pore volume of the wood material is 4.0 cm ^{3 /g or less. If the pore volume of the wood material is 4.0 cm 3 /} g or less, the tracheids in the material are sufficiently crushed, making it difficult for air to be retained, and making it difficult for the material to float on water.

It is also preferable that the average pore diameter of the wood material is 1.0 μm or less. If the average pore diameter of the wood material is 1.0 μm or less, air is less likely to be retained within the material as described above. In addition, the small pore diameter makes it easier for water to penetrate into the material due to the capillary effect, increasing water absorbency and making it less likely to float on water.

In the artificial turf structure having the above-mentioned configuration, the wood material constituting the infill can be wood pellets that have been soaked in water and dissolved.
Wood pellets, which are made by drying and crushing wood chips and then compressing and molding them into granular lumps, are wood chips in which the fibers have been crushed as described above, and when they are immersed in water, their volume expands to about two to five times its original size. By unwrapping and spreading them out in this expanded state, wood chips with a higher bulk density than before compression can be obtained, and these can be used as filler materials.
Any wood pellets, such as white pellets or whole wood pellets, can be used as the wood material.

In the artificial turf structure having the above-mentioned configuration, the pile of the artificial turf can be a crimped pile. Even a crimped pile can create a texture similar to that of natural turf, and the pile can be given a suitable flexibility to improve the cushioning properties of the artificial turf surface.
Furthermore, in an embodiment in which filler is filled into the pile of artificial turf, the filler is covered by the curled pile, so less of the filler is knocked away by raindrops during rainfall compared to straight pile. Furthermore, because the filler is held down by the curled pile, the filler is less likely to scatter even in strong winds or when subjected to the impact of a bouncing ball when playing ball games on the artificial turf, making it possible to prevent the filler from flowing out during heavy rainfall.
In addition, the use of crimped pile prevents sunlight from reaching the infill directly, preventing the infill from heating up, and the turf surface disperses light and reduces glare, making it easier on the eyes of players and spectators.
The crimped pile may be made of any suitable material and specifications, such as green or dark green crimped polyethylene monofilament, and the processing method for crimping the pile may be any suitable method, such as buckling, false twisting, or knit/de-knit processing.

In the artificial turf structure having the above-mentioned configuration, a filler layer is formed in which filler is filled into the pile of the artificial turf, and this filler layer can be made up of at least two layers, with the filler in the topmost layer containing the wood material and the filler in the layers below that containing silica sand.
The silica sand contained in the infill layer has a certain weight, so by placing it in the lower layer, it prevents the artificial turf from rolling up and moving, and also blocks heat from reaching the artificial turf base fabric. In addition, since it is inorganic, it is difficult for insects to breed. By placing a filler containing wood material in the upper layer, the upper layer becomes a buffer layer and gives the artificial turf cushioning, reducing the burden on the knees, waist, and other parts of the body of the person playing on the artificial turf, preventing abrasions, and improving the performance of the player. By placing a filler containing wood material in the upper layer, the appearance and performance of the artificial turf are improved, and the artificial turf can be protected and its durability increased. As described later, the filler made of wood pellets has a moisturizing property and is effective in dealing with heat (generation of heat of vaporization), and can provide a comfortable activity environment for the players and adults and children who play on the artificial turf or engage in outdoor activities.
The infill layer formed in the pile of the artificial turf may be composed of three or more layers. In this case, it is preferable that the infill material containing the wood material is disposed as the infill material of the top layer. Also, silica sand and the infill material containing the wood material may be mixed, and the mixed infill layer may be laminated in one or more layers in the pile of the artificial turf.
The length of the pile of the artificial turf and the thickness of the infill layer formed in the pile can be set appropriately depending on the type of ball game played on the artificial turf field, the artificial turf construction standards stipulated for that ball game, and other uses of the artificial turf.

In the artificial turf structure having the above-mentioned configuration, the artificial turf may be provided on a buffer layer.
According to this, an artificial turf field can be formed by laying a cushioning material made of an elastic material on the foundation of the field to provide a cushioning layer, laying a base cloth with artificial turf piles planted on top of that, and filling the piles with a filler containing a wood material. By appropriately selecting the elastic material and thickness of the cushioning material, the cushioning properties of the artificial turf surface can be appropriately set, and if the ground for a ball game is constructed using an artificial turf structure, it can be made to comply with the specifications stipulated in the rules of that ball game, for example, if it is a soccer field, it can be made to comply with the standards of the JFA or FIFA. Depending on the use of the artificial turf, the artificial turf may be constructed without providing a cushioning layer.

In addition, one embodiment of a method for laying an artificial turf structure having the above-described configuration can be carried out through the steps of: a step of laying the artificial turf; a wood pellet scattering step of scattering wood pellets on the artificial turf; a wood pellet burying step of burying the scattered wood pellets between the piles of the artificial turf; a watering step of spraying water on the buried wood pellets to cause them to absorb water; and a wood pellet thawing step of thawing the wood pellets that have absorbed water.
The method of laying the artificial turf structure is as follows: first, as described above, a cushioning material is laid on the foundation of the field to form a cushioning layer, and then a base cloth with artificial turf piles planted therein is laid on top of this cushioning layer to lay the artificial turf. Depending on the use of the artificial turf, the artificial turf may be laid by laying the base cloth with artificial turf piles planted directly on the foundation.
Next, the wood pellets are evenly spread on the top surface of the artificial turf and buried between the piles. The wood pellets can be spread using a top dresser that is used to spread sand on the artificial turf. If necessary, an appropriate amount of silica sand can be spread on the artificial turf before spreading the wood pellets.
Once the woody pet is buried between the piles, water is sprayed onto the surface of the artificial turf to allow the woody pet to absorb a sufficient amount of water.
Once the woody pet expands due to being soaked in water, it is unraveled and spread out, and entangled with the pile of the artificial turf so that it is immersed in the artificial turf. The operation of unraveling the expanded woody pet can be carried out, for example, using a turf tuner that is used when erecting the pile.
Then, as necessary, the infill material is dug up, the level is adjusted, etc., and the installation of the artificial turf structure is completed.

Another embodiment of laying an artificial turf structure can be a method comprising the steps of laying the artificial turf, immersing wood pellets in water to absorb the water, loosening the wood pellets that have absorbed the water, and filling the loosened wood pellets between the piles of the artificial turf.
The method for laying the artificial turf structure having the above-mentioned configuration is not limited to the above-mentioned embodiment, and the artificial turf can be laid by any suitable method depending on the location, environment, laying area, etc. Any suitable method can be used for maintaining the laid artificial turf.

The artificial turf structure of the above configuration can be applied to grounds for various ball games, such as baseball, soccer, futsal, rugby, tennis, and hockey, to create artificial turf fields. It can also be applied to golf tee grounds, grounds (gardens) of educational facilities and recreational facilities, and grass ski slopes. In this specification, the names ground, field, court, and pitch are all used interchangeably to refer to the places where artificial turf is laid.

1 is a partially cutaway external view of one embodiment of an artificial turf structure of the present invention. FIG. 1A to 1E are diagrams showing the test results of the outflow evaluation of the fillers of Example 1, Example 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively. 1 is a graph showing the results of a test to confirm the temperature suppression effect in a dry state of the fillers of the examples and comparative examples. 1 is a graph showing the results of a test to confirm the temperature suppression effect in a wet state of the fillers of the examples and comparative examples.

The present invention will be described in detail below based on preferred embodiments. Note that the present invention is not limited to the following embodiments. The embodiments are merely examples, and can be modified as appropriate without departing from the spirit of the present invention.

FIG. 1 shows an artificial turf structure according to one embodiment of the present invention.
The illustrated artificial turf structure 1 is constructed by laying a cushioning material 2 made of an elastic material on the foundation of the field (not shown), laying a base fabric 3 with artificial turf piles 4 planted on top of this cushioning material 2, and filling the piles 4 with filler material 5 made of a wood material.

The filler 5 made of the wood material is made by compressing wood chips to crush their fibers, and then expanding the compressed state to increase the bulk density. The bulk density of the filler 5 in the completely dry state is 0.2 g/ ^cm3 or more.

Wood pellets can be used as the wood material constituting the infill 5. In that case, the artificial turf structure 1 can be laid, for example, as follows.
That is, first, cushioning material 2 is laid on the foundation of the field, and then base fabric 3 with piles 4 planted on top of that is laid to lay the artificial turf. After that, wood pellets are scattered on the piles 4 of the artificial turf so that they are buried between the piles 4, and then water is sprayed on the buried wood pellets to absorb the water and cause them to expand. After that, the expanded wood pellets are unraveled and expanded, and entangled with the piles 4 to adjust the level of the entire artificial turf. Through these steps, the artificial turf structure 1 can be laid.

According to the artificial turf structure 1 of this embodiment, the filler 3 is made of compressed wood chips and has a bulk density of 0.2 g/cm3 or ^more in its total dry state, so that the bulk density is greater than that of the wood chips before compression and the water absorption is improved. Therefore, even if water accumulates on the artificial turf due to rainfall, the water does not float up but sinks into the water and remains within the artificial turf, and does not flow out outside the field on which the artificial turf is laid, and it is possible to exhibit cushioning properties equivalent to those of filler made of natural materials that have been used conventionally.
The filler 5 made of wood material has a brown or warm colored surface, which makes it difficult for it to absorb heat from sunlight, making it possible to prevent the surface temperature of the artificial turf from rising on sunny days. In addition, the filler 5 is porous and therefore easily absorbs water, so by sprinkling water on the artificial turf and storing the water in the filler 5, it is possible to prevent the surface temperature of the artificial turf from rising during the day.

The infill material 5 made of wood material that constitutes the artificial turf structure 1 was evaluated as follows for each natural material.

Example 1
As the wood material constituting the filler, white pellets (Thoreau's pellets; manufactured by Catalog House Co., Ltd.), which are wood pellets, were used.
8 g of white pellets were placed in a container, and water was poured into the container so that the pellets were completely submerged. Two minutes after the water was poured in, the pellets absorbed the water and expanded in volume by about 4.6 times compared to before the water was poured in. The weight at the time of water absorption saturation was 34 g.
The expanded white pellets were dried and evaluated for use as a filler.

Example 2
As the wood material constituting the filler, whole wood pellets (Pure No. 1; manufactured by Kamiina Forestry Association) were used.
6 g of whole wood pellets were placed in a container and water was poured into it so that the pellets were completely submerged. Four minutes after the water was poured in, the pellets had absorbed the water and expanded in volume by about 2.6 times compared to before the water was poured in. The weight at the time of water absorption saturation was 26 g.
The expanded whole wood pellets were dried and evaluated for use as a filler.

(Comparative Example 1)
As a wood material, an evaluation was carried out when cedar sawdust (Suginami sawdust; manufactured by Takeshimaya Lumber Store) was used as a filler.

(Comparative Example 2)
As a wood material, an evaluation was carried out when a natural filler made of natural palm or coconut (manufactured by RISE CORPORATION) was used as a filler.

(Comparative Example 3)
As a wood material, an evaluation was performed when the raw material of white pellets (manufactured by Catalog House Co., Ltd.) before being processed into wood pellets was used as a filler.

[Measurement of bulk density]
The bulk density of the fillers in each of the Examples and Comparative Examples was measured in a completely dry state (dried in an incubator at 103±2° C. for 4 hours) and in an air-dried state. The results are shown in Table 1.

[Measurement of voids inside materials]
The average pore diameter, pore volume, and porosity of the fillers of Example 1 and Comparative Examples 1 and 2 were measured using an automatic mercury porosimeter pore distribution measuring device (Autopore IV9520; manufactured by Shimadzu Science East Japan Co., Ltd.). The results are shown in Table 1.

[Luminance measurement]
The fillers of Examples 1 and 2 and Comparative Examples 2 and 3 were measured for luminance using a color luminance meter (CS-160; manufactured by Konica Minolta, Inc.). The measurements were performed in the same indoor environment by capturing the measurement object through a viewfinder, and the displayed luminance values were recorded. The results are shown in Table 1.

[Runoff assessment]
The outflow evaluation of the fillers of each of the Examples and Comparative Examples was carried out.
The evaluation was performed by placing 50 mL of the filler in a beaker, pouring 100 mL of water into it, and checking whether the filler floated on the water. The appearance of the fillers of each Example and Comparative Example after pouring water into the beaker is shown in FIG. 2.
As shown in the figure, most of the fillers in both Examples 1 and 2 remained at the bottom of the beaker. The results are indicated in Table 1 with "◯".
On the other hand, most of the filler in Comparative Example 1 and the raw material in Comparative Example 3 floated, and almost all of the filler in Comparative Example 2 floated. The results are indicated in Table 1 with "X".

[Temperature suppression effect 1]
For the fillers of Examples 1 and 2 and Comparative Example 2, the temperature suppression effect of the dried filler was confirmed using a solar power meter (SPM-SD; manufactured by Sato Shoji Co., Ltd.) and a thermography camera (E6-XT; manufactured by FLIR Systems, Inc.).
The confirmation was carried out by filling a 140 ^cm3 container with the dry filler and simultaneously measuring the surface temperature of the filler with a thermographic camera and the solar radiation intensity with a solar power meter under a clear summer sky.
The results are shown in Figure 3. In the graph, the horizontal axis indicates solar radiation intensity and the vertical axis indicates the surface temperature of the filler. Table 1 shows the temperature reached on the surface of the filler at a solar radiation intensity of 715 W/ ^m2 .

[Temperature suppression effect 2]
For the fillers of Examples 1 and 2 and Comparative Example 2, the temperature suppression effect of the wet filler was confirmed using the above-mentioned thermographic camera and electronic balance (FX-500i; manufactured by A&D Co., Ltd.).
To confirm this, the dry filler was filled into a 140 ^cm3 container, and water equivalent to 6 mm of precipitation was poured into the container. The weight of the filler in the container was then measured under clear summer skies, and the change in the surface temperature of the filler over time was measured using a thermographic camera.
The results are shown in Figure 4. In the graph, the horizontal axis indicates the time of measurement, and the vertical axis indicates the percentage change in weight from the initial wet state (100%) of the filler and the surface temperature of the filler. The maximum temperature reached on the surface of the filler is shown in Table 1.

As is clear from the test results of the runoff evaluation, it was confirmed that, among the natural fillers, Examples 1 and 2 did not float on water, while the fillers and materials of Comparative Examples 1 to 3 float on water.
The infill material of Comparative Example 2 is a general infill material made from natural materials, and has the problem of flowing out to the outside of the artificial turf pitch when water accumulates on the artificial turf. Most of the infill materials of Examples 1 and 2 do not float on water, but remain submerged in the water, and there is no risk of flowing out like the infill material of Comparative Example 2.
Both the fillers of Examples 1 and 2 are made of wood pellets, and in the process of compressing the wood chips into pellets, the wood fibers are crushed, the bulk density increases, and air is difficult to retain inside. This is also clear from a comparison of the average pore size, pore volume, and porosity of the fillers of both Examples and those of Comparative Example 2, which is a filler made of uncompressed natural materials. The values of the fillers of Examples 1 and 2 are extremely smaller than the values of the filler of Comparative Example 2, which can be said to be evidence that air is difficult to retain in the filler. In addition, the fillers of Examples 1 and 2 do not float on water even though their bulk density is less than 1.0. It is presumed that the wood chips are altered by compressing the wood chips into pellets, improving their hydrophilicity, and that the porosity is reduced by crushing the inside of the wood, and the pore size is reduced, which absorbs water due to the effect of capillary phenomenon, and therefore the buoyancy does not work, and the submerged state is maintained.

The luminance (cd/ ^m2 ) of the fillers of the above Examples and Comparative Examples is 157.1 for Example 1, 121.0 for Example 2, 118.3 for Comparative Example 1, 30.5 for Comparative Example 2, and 169.5 for Comparative Example 3. The fillers of both Examples have a greater luminance than the filler of Comparative Example 2, and therefore absorb less heat when exposed to sunlight, which is thought to have the effect of suppressing the rise in temperature of the artificial turf surface during the day.
In addition, in the temperature suppression effect 1, the degree of increase in the surface temperature of the dried filler when exposed to solar radiation was confirmed. The surface temperature (°C) of the filler when the solar radiation intensity was 715 (W/ ^m2 ) was 64 for Example 1, 70 for Example 2, and 77 for Comparative Example 2, and as shown in Figure 3, since each filler was a filler made of natural materials, no difference was observed in the rate of temperature increase relative to the solar radiation intensity. It was confirmed that the fillers of Examples 1 and 2 were able to suppress the temperature increase to a smaller extent even when the solar radiation intensity increased, compared to Comparative Example 2, which is a filler made of a general natural material.
Furthermore, in the temperature suppression effect 2, the degree of increase in the warm surface temperature of the wetted filler when exposed to solar radiation was confirmed. As shown in FIG. 4, the rate at which the wetness rate of the 100% wetted filler decreases when exposed to solar radiation was not significantly different between the fillers of Example 1, Example 2, and Comparative Example 2. The surface temperature (°C) of each filler was highest around 2:00 p.m., when the amount of solar radiation was at its maximum, but the filler of Comparative Example 2 reached 55, while the fillers of Example 1 and Example 2 were both 46, and it was confirmed that the temperature difference was nearly 10°C. In the artificial turf using the fillers of Example 1 and Example 2, it is considered effective to spray water on the artificial turf surface in advance to make the filler soaked in water in order to suppress the temperature rise of the artificial turf surface during the day.

From the above evaluation results, it can be said that the infill materials of Examples 1 and 2 do not float easily on water, and if they are incorporated into the pile of artificial turf to construct an artificial turf field, even if water accumulates on the artificial turf due to rainfall, it will not float up but will remain inside the artificial turf, preventing it from flowing outside the field. In addition, since they have a temperature suppression effect when exposed to sunlight, it is also possible to suppress the rise in the surface temperature of the artificial turf during the day, and they are extremely useful as infill materials to replace the general natural material infill materials used in conventional artificial turf.

The configuration and form of the artificial turf structure described and illustrated above are merely examples, and the present invention is not limited to the configuration and form described and illustrated, and other appropriate configurations and forms are possible.

1 artificial turf structure, 2 cushioning material, 3 base fabric, 4 pile, 5 filling material

Claims (13)

In an artificial turf structure in which infill material is filled between the piles of the artificial turf,
The filler contains a wood material, which is obtained by soaking and dissolving wood pellets in water and has a bulk density of 0.2 g/cm3 or more in a completely dry ^state . 2. The artificial turf structure of claim 1, wherein the wood pellets are white pellets or whole wood pellets. The artificial turf structure according to claim 1 or 2, wherein the porosity of the wood material is 80% or less. 3. The artificial turf structure according to claim 1 or 2, wherein the wood material has a pore volume of 4.0 cm ³ /g or less. The artificial turf structure according to claim 1 or 2, wherein the average pore size of the wood material is 1.0 μm or less. The artificial turf structure according to claim 1 or 2, wherein the pile of the artificial turf is a crimped pile. The filler layer, which is the portion filled with the filler, is composed of at least two layers,
The filler of the top layer of the filler layer contains a wood material;
3. The artificial turf structure according to claim 1, wherein the filler in the layer below the layer contains silica sand. The artificial turf structure according to claim 1 or 2, wherein the infill layer, which is the portion filled with the infill material, is formed by mixing a infill material containing silica sand and wood material. The artificial turf structure according to claim 1 or 2, in which the artificial turf is provided on a cushioning layer. A method for laying an artificial turf structure according to claim 1 or 2, comprising:
Laying artificial turf;
A wood pellet scattering step of scattering wood pellets on the artificial turf;
a wood pellet burying step of burying the scattered wood pellets between piles of the artificial turf;
a watering process in which water is sprayed onto the buried wood pellets to allow them to absorb water;
A wood pellet disintegration process for disintegrating the wood pellets that have absorbed water;
A method of laying an artificial turf structure comprising: A method for laying an artificial turf structure according to claim 1 or 2, comprising:
Laying artificial turf;
A step of soaking the wood pellets in water to absorb the water;
A step of thawing the wood pellets that have absorbed water;
filling the gaps between the piles of the artificial turf with the decomposed wood pellets;
A method of laying an artificial turf structure comprising: A ball game ground constructed using the artificial turf structure according to claim 1 or 2. A teeing ground constructed using the artificial turf structure according to claim 1 or 2.

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