JPS5996306A - Athletic field made of artificial turf - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an athletic field made of artificial turf, and more particularly to an athletic field made of artificial turf, which is formed by filling the artificial turf with dry sand.

Generally, artificial lawns are made of flat pile threads made from synthetic resins such as polyamide, acrylic, vinylidene chloride, or polypropylene, which are grafted onto a backing fabric using various methods. The pile length and turf density will vary slightly depending on the playing field, such as a tennis court or soccer field, but the length is generally 7 to 7.
It is around 12mm. Artificial lawns have become rapidly popular in recent years because they are more durable and easier to maintain than natural lawns, but there are still issues to be solved regarding their characteristics and construction. Challenges remain.

According to previous examples, it has been reported that by filling the grains of an artificial lawn with dried sand (mineral particles), the characteristics of the artificial lawn can be made to more closely resemble those of a natural lawn. Although this dry sand satisfies the buffering capacity of the artificial lawn and the ability to prevent spikes from getting caught, the following points must be kept in mind.

In other words, in order to increase the water retention capacity of this sand layer, the finer the grain size, the better; however, if too fine sand is used,
Not only does it harden over time and lose its proper cushioning properties, but the sand gets blown up by the wind during or after sanding, which is unfavorable in terms of occupational safety and health and environmental health. This dust generation is particularly problematic in indoor courts. For this reason, in the past, soil fixatives were sprinkled on top of the filled sand layer to harden the surface, or the grain size of the sand was kept to a certain level, and moisture retaining materials such as vermiculite or calcium chloride were used instead. It is sometimes mixed with

However, methods using soil fixatives are not very permanent;
This is troublesome in terms of maintenance and management, and is also undesirable in terms of cost. On the other hand, as for the moisture retaining material, mixing it into the sand layer requires a certain amount of effort, and like the former, cost problems remain.

Therefore, an object of the present invention is to provide a flat stadium surface that has characteristics similar to natural grass in terms of buffering capacity and ability to prevent spikes from getting caught, as well as water retention capacity, and which is easy to maintain after rain. To provide an athletic field made of artificial grass having a sand layer that is easy to clean and generates extremely little dust due to wind, etc.

The above object is achieved by first forming a lower layer of fine dry sand below the grain of the artificial lawn, and filling and layering coarse dry sand on top of the lower layer. In this case, the fine dry sand preferably contains 80% or more of a particle size of 100 mesh to 28 mesh, and the coarse dry sand preferably contains 80% or more of a particle size of 70 mesh to 14 mesh.

Further, according to the present invention, the ground below which the artificial lawn is laid is made of crushed stone, volcanic gravel, or/and sand and is permeable, and the upper surface is made of relatively fine particles of slag dust, lime dust, and/or crushed stone dust. A smooth finish is achieved by scattering granular materials and then scattering appropriate soil fixing agents such as calcium chloride, silica sol, lime, and gypsum on top of the granules. In this case, the toughs used have a particle size of about 5 mm or less, preferably 3 mm or less.

Furthermore, silica sol or the like is made into a low-viscosity aqueous solution by adding an appropriate amount of water and then sprinkled on the dust. The ground formed in this way in the present invention is constructed as a flat and firm ground because the dust and soil fixing agent prevent the movement of individual crushed stones and the like constituting the upper surface thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

This athletic field consists of a ground (1) whose upper surface is substantially flat and an artificial lawn (1) laid on this ground (1).
2) and dry sand (3) filled into the grass grains of this artificial lawn (2). In this example, the ground (1)
consists of stabilized crushed stone, volcanic gravel or/and sand. That is, a stabilizer such as cement or quicklime is mixed into the crushed stone, etc., and an appropriate amount of clay as a moisture donor is added as needed, and then it is spread evenly and the surface is compacted or not compacted. Although it is generally flat. However, the ground (1) is usually made of the above-mentioned crushed stone with a particle size of about 25 mm in order to have sufficient support capacity against the load applied from above after completion, so its upper surface is uneven. .

Therefore, according to the present invention, slag dust, lime dust or/and crushed stone dust (4) having a particle size of about 5+n+n or less, preferably 3 mm or less is sprinkled on the surface of the ground (11), and calcium chloride is further sprinkled thereon. In addition,
Finished virtually flat.

With this configuration, the upper surface of the ground (1), which lacks stability and has many gaps between crushed stones, is flattened because crushed stones, etc., which are relatively large in diameter and have many surface irregularities, are spread evenly. Since the artificial turf is stabilized and stabilized, the artificial turf can be laid more evenly and stably.

The artificial lawn (2) consists of a lining base fabric (5) and this base fabric (5).
) and a pile yarn (6) planted therein. In this case, the base fabric (5) is made of crushed stone, volcanic gravel, or/and sand that has been treated to stabilize the ground (1), and prevents its stability from being compromised and weakened by rainwater penetration. Therefore, it is made non-water permeable. This water impermeability can be obtained, for example, by banking rubber or urethane resin on the base fabric (5).

The pile yarn (6) can be made from various synthetic resins, but in terms of appearance and texture, it is more similar to natural grass, and in terms of durability, polyamide, polyethylene terephthalate, polyurethane, polyvinylidene chloride, polypropylene, etc. or acrylic resins are preferred, and are made from slit yarns obtained by slicing films of these resins, or flat yarns formed by melt spinning through a nozzle having irregular cross-sectional holes. Considering that this artificial grass (2) is used in tennis courts, soccer fields, baseball fields, etc. in place of conventional natural grass, its pile length is between 10 mm and 4 mm.
Preferably, it is 0 mm. According to this invention, the dry sand (3) has a lower layer (7) made of fine sand filled on the base fabric (5) and an upper layer (8) made of coarse sand layered thereon. It consists of a two-layer structure. In this case, fine sand is defined as containing preferably 80% or more of sand with a grain size of 100 to 28 mesos (approximately 0.15 mm to approximately 0.6 mm), while coarse sand is defined as having a grain size of 70 mesh to 14 mesh (approximately 0.21
mm to about 1.2 mm), preferably 80%
It is defined as including the above. This dry sand (3) is spread on the artificial lawn (2) and filled into the grass grains, but if the particle size is finer than 100 mesh, it will be gradually pounded and hardened by the pressure of the players. In addition, there is a risk that it may be blown up as dust, which is unfavorable from the standpoint of occupational safety and health as well as environmental health, especially in the case of indoor facilities. In view of this, in this invention, the particle size of the fine sand used for the lower layer is within the above range, so that when the wind friction speed is around 15 cm per second (corresponding to the wind speed on the ground of 4 m per second), the pile yarn (
Coupled with the erosion control effect (6), there is almost no blowing away, and therefore the amount of dust generated during construction is extremely small. Furthermore, considering the relationship with the particle size, the water retention capacity and drainage performance were both satisfactory to a certain extent, and the results were almost comparable to those of conventional methods, even without the addition of moisture retention materials such as vermiculite and calcium chloride. water retention capacity is shown. Furthermore, since the coarse sand having the particle size range described above is layered on the lower layer of fine sand, there is almost no risk that the entire layer will be blown away by the influence of the wind.

On the other hand, dry sand (3) including the lower layer (7) and the upper layer (8)
) has a layer thickness of about 70% to 1 of the length of the pile yarn (6).
10% is appropriate. Note that this value is based on the time of completion of construction, and in reality, the level will decrease over time due to rainfall and tread pressure, and will stabilize after about a month. Therefore, the layer thickness is selected in relation to, for example, the bouncing characteristics of the poles and the aesthetic appearance of the artificial lawn. In other words, pile yarn (
If you add enough sand to the point where the tip of the pole (6) is covered, the pile thread (6) will stand upright and become rigid, which will increase the pole's nose and improve its durability, but on the other hand,
The green color of the artificial lawn (2) becomes less conspicuous and the aesthetic appearance is slightly different. On the other hand, if more of the tips of the sand (3 points less, 6 pile yarns) are made to protrude from the top of the sand layer, the playing surface will be more flexible and the bounce of the pole will be lower.

Moreover, although the green color of the artificial lawn (2) stands out and is aesthetically pleasing, on the contrary, the pile yarn (6) wears out more quickly. Note that the ratio of the layer thicknesses of the lower layer (7) and the upper layer (8) can be appropriately determined by taking into consideration water retention and the like.

As is clear from the above description of the embodiments, according to the present invention, the base is made of crushed stone, volcanic gravel, sand, etc. to have a water-permeable structure, and moreover, the grass grains of the artificial lawn are filled with a large amount of sand. Because of this, water drainage is good even when there is a relatively large amount of rainfall, and maintenance work during rainy periods is significantly reduced.
Because the ground is formed from easily available materials such as crushed stone, volcanic gravel, and sand, it is cheaper and easier to construct than asphalt ground when converting a conventional clay court or Antuca court into an all-weather court. can. In addition, the upper surface of the ground, which is made of crushed stone, etc. (a material with relatively sharp edges and many surface irregularities), has a grain size of 5 m and is hardened with a soil fixative prior to laying the artificial lawn.
The ground is smoothed by spreading slag dust, lime dust, and/or crushed stone dust of 3 mm or less, preferably 3 mm or less, and the displacement of the crushed stone is suppressed, so that the ground is constructed as a flat and firm ground. This means that an artificial grass athletic field that is stable in appearance and dimensions can be obtained.

Furthermore, according to the present invention, a lower layer consisting of fine sand containing 80% or more of sand in the range of 100 mesh to 28 mesh is formed between the grains of the artificial lawn, that is, between the pile threads;
By laminating the upper layer of coarse sand containing 80% or more of sand in the range of 14 to 14 mm, it is easier to spread the sand on the artificial lawn and fill it into the grass grains. The amount of scattering is small, and there is almost no risk of causing occupational safety and health problems. In addition, since the fine sand in the lower layer is held down by the coarse sand in the upper layer, there is no need to spread a soil fixing agent on the sand layer to harden the surface of the sand layer in order to prevent the sand from scattering as in the conventional method. Furthermore, since it exhibits a good value for water retention capacity, there is no need to mix water retention materials such as vermiculite or calcium chloride. Therefore, it is easy to construct and is advantageous in terms of cost.

[Brief explanation of drawings]

The figure is a cross-sectional view showing a portion of an athletic field made of artificial grass according to the present invention. In the figure, 1 is the ground, 2 is the artificial lawn, 3 is the dry sand 4 is the layer consisting of slag dust etc. and soil fixative, 5 is the lining base fabric,
6 is a pile yarn, 7 is a lower layer, and 8 is an upper layer. Patent applicant: Sumitomo Rubber Industries, Ltd.

Claims (2)

[Claims] (1) A permeable ground made of crushed stone and/or sand with a substantially flat upper surface, an artificial lawn laid on the ground, a base fabric, and an artificial lawn planted on the base fabric. Ta1
The artificial lawn comprises pile yarns having a length in the range of 0+nn+ to 40 mm, and dry sand filled into the artificial lawn with a thickness of 70% to 110% of the pile length, the dry sand comprising: An athletic field made of artificial grass having a 2N structure consisting of a lower layer made of fine sand layered on the base fabric and an upper layer made of coarse sand layered on the lower layer, wherein the upper surface of the permeable ground has a particle size of approximately 5
It is characterized by being formed into a substantially flat surface by spraying slag dust, lime dust, crushed stone dust, or a mixture thereof with a size of 3 mm or less, preferably 3 mm or less, and further scattering a soil fixing agent such as calcium chloride. Artificial grass sports field. (2) The lower layer of the two-layered dry sand filled in the artificial lawn contains 80% or more of sand with a particle size in the range of 100 mesh to 28 mesh, and the upper layer of the dry sand contains:
The artificial grass athletic field according to claim (1), which contains 80% or more of sand with a particle size in the range of 70 mesh to 14 mesh.