JPH0437923Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to an athletic field made of sand-filled artificial turf, which is made by filling the grains of artificial turf with fine sand. This invention relates to an athletic field made of artificial turf that is maintained.

Sand-containing artificial turf is similar to natural turf both in terms of characteristics and appearance, and is therefore used in various athletic fields, including tennis courts and soccer fields. This artificial lawn consists of synthetic resin fibers planted on a backing base fabric to a length of about 20 to 30 mm, but the synthetic resin fibers currently in use are nylon (polyamide). , polypropylene, polyvinylidene chloride, etc. Although nylon has excellent abrasion resistance and elastic recovery power (the ability of fibers that have been trampled to recover to their original upright state), it feels a little harder than natural grass. On the other hand, polypropylene is softer than nylon and has a feel similar to natural grass, but its abrasion resistance is generally inferior to nylon, depending on the denier number. Polyvinylidene chloride is as soft as polypropylene, but is said to have poor weather resistance.

On the other hand, when we observed cases where sand was filled in artificial lawns made of these synthetic fibers, we found that under actual usage conditions, nylon stands too upright, causing the sand filled in the grass to scatter. (It moves too much.) Therefore, even if you fill sand evenly across the front of the artificial turf, the sand where your feet land on the playing field or the trajectory you take when sliding will be in a different place. As a result, the sand could not be kept uniform after several competitions, and it was found that it was necessary to level the sand frequently in order to maintain the uniformity of the sand. In addition, in the case of polypropylene, at the beginning of construction, the leaf tips curl moderately due to foot trampling and friction, and the curled leaf tips moderately suppress the scattering (movement) of sand, but over a long period of time. During use, the curl of the leaf tips becomes stronger and the scattering (movement) of sand becomes more pronounced.
It has been found that there is a tendency to press down too much, which makes the feet less slippery, and in addition, it feels hard when landing.

Therefore, this idea was made after comparing the characteristics of the above-mentioned nylon fiber and polypropylene fiber and their effect on sand.The purpose of this idea was to create a mixed tuft by using both fibers together, which would have better wear resistance. In addition to having good properties, it also has interference performance that is almost the same as natural grass.
To provide an athletic field made of artificial grass capable of maintaining appropriate scattering (movement) of filled sand for a long period of time.

That is, nylon fibers and polypropylene fibers are mixed and planted on the lining fabric,
The aim is to use an artificial lawn in which the mixing ratio of polypropylene fibers and nylon fibers is 25:75 to 75:25.

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

As shown in Figure 1, this artificial turf sports stadium has a permeable base made of permeable asphalt concrete, chestnut stone, crushed stone, etc. An artificial lawn 2 is laid on a base 1 of an impermeable structure consisting of a substrate 1, and fine sand 3 of, for example, silica sand No. 5 to No. 8 is placed within the grain of the artificial lawn 2.
In this case, the artificial lawn 2 is formed by filling the nylon fibers 4, which are shown with thick lines for convenience, and the polypropylene fibers 5, which are shown with thin lines for convenience, in an arbitrary ratio. It consists of a mixed tuft mixed with. In FIG. 1, the mixing ratio of nylon fibers 4 and polypropylene fibers 5 is 1:2.

As illustrated in FIG. 2, such an artificial lawn 2 is made by tufting nylon fibers 4 and polypropylene fibers 5 alternately at predetermined intervals, preferably at the same pitch, onto a backing base fabric 6. It is made by cutting each loop part as shown in the imaginary lines. in this case,
If the polypropylene fibers 5 are cut so that they are slightly longer than the nylon fibers 4, taking into account the length at which the ends thereof will curl, the polypropylene fibers 5
When the tip of the polypropylene 5 is stepped on by the sole of a shoe and curls moderately, the height of the polypropylene 5 becomes slightly higher, or the height of both fibers 4 and 5 becomes almost the same, so the advantages of both are combined to provide an appropriate level of softness. Due to its wear resistance and prevention of excessive sand scattering (movement),
Appropriate sand movement can be obtained over a long period of time. In addition, in this example, the ratio of nylon fiber 4 and polypropylene fiber 5 is 2:3,
These fibers may be monofilaments or slit yarns.

Furthermore, unlike the above embodiment, in the embodiment illustrated in FIG. The material is tufted into a pile shape on a backing base fabric 6, and the loop portion is cut as shown in the imaginary line in the figure.

In this way, when nylon fibers 4 and polypropylene fibers 5 are twisted together to form a mixed tuft, both fibers are cut to approximately the same length, but as illustrated in FIG. The tips of the polypropylene fibers 5 are stepped on by the soles of shoes, etc., and are moderately curled to prevent excessive scattering (movement) of the sand 3. On the other hand, the nylon fibers 4 protrude by the curled portion of the polypropylene fibers 5. This will prevent wear.

In addition, the nylon fiber 4 in the above-mentioned example
The ratio of nylon fibers 4 to polypropylene fibers 5 is small, but if the possibility of wear is expected to be high, the ratio of nylon fibers can be increased to strengthen the abrasion resistance. Often, it can be changed arbitrarily by taking into consideration the denier number of the yarn used, the composition, or the type of athletic field to which it is applied, but considering the sand holding property of the polypropylene fiber 5, the proportion of the polypropylene fiber 5 is is preferably between 25 and 75 when the total is 100.

Figure 5 shows data obtained by experimentally measuring the amount of concaveness due to the movement of sand between an artificial lawn made of nylon fibers and polypropylene fibers as described above, and a conventional artificial lawn made of only nylon fibers and polypropylene fibers. This is a graph showing. The experiment consisted of an artificial lawn A consisting only of nylon fibers, an artificial lawn B consisting only of thick polypropylene fibers, an artificial lawn C consisting only of thin polypropylene fibers, and nylon fibers and polypropylene fibers planted alternately. Mixing ratio is 1:1
I made an artificial lawn D. The height of each fiber was set to 20 mm, and sand was filled up to the tips of the artificial grass leaves (20 mm). 55 kg of 150 x 60 mm is placed on the artificial lawn constructed in this way and each size is 300 x 500 mm.
A rubber plate with grooves of 5 mm width is attached to the back side of an iron plate to form a sag, which is then moved back and forth from one end of each artificial lawn to the other, moving as each fiber is mowed down by the groove. The amount of sand that decreases is taken as the decrease value of sand in the depth direction, and this is taken as the amount of concavity of sand movement. As you can see from the graph in Figure 5, in the case of nylon artificial lawn A, when the sag is moved back and forth 40 times, the sand moves by about 4 mm, and when it goes back and forth 200 times, the sand is reduced by about 6 mm. . On the other hand, on artificial lawns B and C made of polypropylene, the amount of sand decreases by around 1 mm even if the sag is moved back and forth 40 times. Even after going back and forth 200 times, in the case of B, it is about 2 mm, and in the case of C
Even in the case of , the decrease remains at about 3 mm. On the other hand, artificial lawn D made of nylon and polypropylene
In this case, after about 40 times of sagging, the thickness is about 1 mm, which is about the same as that of polypropylene artificial grass.
The amount of dent caused by the sand movement is small. On the other hand, after going back and forth 200 times, it decreased to less than 3 mm.
Compared to artificial lawns made only of polypropylene, the amount of depression due to sand movement is greater.

However, the fact that the amount of sand movement is small even after 200 times of hanging means that, as mentioned above, in the case of polypropylene, the tip of the leaf curls due to trampling and friction, which holds the sand and prevents it from moving. This means that the athlete's feet become less slippery and the landing feels harder. On the other hand, in artificial grass made of nylon and polypropylene, the sand is moved in the nylon portion, allowing the feet to slide appropriately and giving a soft landing feel.

In each of the above embodiments, the mixing ratio of nylon fibers and polypropylene fibers is set by the number of each fiber per unit area, but it may also be set by changing the denier number of each fiber.

As is clear from the description of the examples above, this idea was developed by considering the characteristics of nylon fibers and polypropylene fibers and the effects of these fibers on sand, and by mixing nylon fibers and polypropylene fibers, and by mixing polypropylene fibers and nylon fibers. The mixing ratio was changed from 25:75 to 75:25. Although it is a simple composition of mixing fibers, it effectively brings out the advantages of each fiber and has good abrasion resistance, and has a moderate amount of softness and a suitable sand scattering (movement) prevention effect that allows it to maintain a suitable amount of sand for a long time. An artificial turf athletic field is provided that provides motion.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing an artificial grass athletic field according to this invention, and FIGS. 2 and 3 are views showing the state in which nylon fibers and polypropylene fibers are tufted into a backing fabric, respectively. Fourth
The figure is a partial sectional view showing another embodiment of this invention.
FIG. 5 is a graph showing experimental data on the sand movement state in the case of nylon, polypropylene, and a mixture of nylon and polypropylene. In the drawings, 1 is a base, 2 is an artificial lawn, 3 is sand, 4 is a nylon fiber, 5 is a polypropylene fiber, and 6 is a backing fabric.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An athletic field made of artificial grass, which is constructed by laying artificial grass on a base and filling the turf with sand, where the artificial grass is made of nylon fibers and polypropylene fibers. An athletic field made of artificial grass, characterized in that the polypropylene fibers and the nylon fibers are mixed and planted on a lining base fabric, and the mixing ratio of the polypropylene fibers and the nylon fibers is from 25:75 to 75:25. (2) The artificial lawn according to claim 1, wherein the nylon fibers and the polypropylene fibers are alternately planted on the backing fabric at predetermined intervals. athletic field. (3) The artificial grass athletic field according to claim 1, wherein the actual height of the polypropylene fibers in a finished state is slightly higher than the actual height of the nylon fibers.