Artificial lawn

Abstract

Provided is an artificial lawn that has a high durability and does not undergo fibrillation over a long time. In the artificial lawn, flat filament yarns, which are produced by uniaxially stretching a crystalline plastic material to give a crystal orientation degree of 0.75-0.90, are used as piles (3) to be implanted in a base fabric (2).

Description

TECHNICAL FIELD[0001]The present invention relates to an artificial turf in which piles are implanted in a base fabric, more specifically to a technique for improving the durability of the pile.BACKGROUND ART[0002]An artificial turf in which the space between piles is filled with a filler has spread through various athletic sports facilities, such as a soccer field, a rugby field, and a baseball field, as an artificial turf surface having the characteristics close to natural turf. Recently, the artificial turf has been increasingly used every year for school grounds taking advantage of the feature that the artificial turf is of an all-weather type, and the operating ratio of the artificial turf has been increased.[0003]As one of the artificial turf of this type, a so-called long pile artificial turf is known in which the pile length is set longer than that for conventional artificial turf. In the long pile artificial turf, the properties close to natural turf can be reproduced by fi...

AI Technical Summary

Benefits of technology

[0017]According to the above features of the present invention, the flexibility of a pile can be improved by using, as a pile, a flat filament yarn having a degree of crystal orientation of 0.75 to 0.90 (more preferably 0.75 to 0.85) produced by uniaxially stretching a crystalline plastic, and the resulting artificial turf is not fibrillated over a long period of time but can have stable durability.

[0018]Further, since the flattening ratio (W / H) of the pile is 3.0 to 7.0, wherein H represents the length in the minor axis direction of the cross section of the pile, and W represents the length in the major axis direction of the cross section of the pile, the pile is not liable to wear, and as a result, the progress of fibrillation can be prevented.

[0019]Furthermore, since the length H in the minor axis direction of the cross section of the pile is 180 to 350 μm, the durability of the pile is good. A length H of shorter than 180 μm is not preferred because when the length H is shorter than 180 μm, fibrillation will be liable to occur. Conversely, a length H of longer than 350 μm is not preferred because when the length H is longer than 350 μm, the thickness of the pile will be increased to increase cost, and the pile will be liable to have a bending habit by bending, resulting in impairing the pliability and appearance as an artificial turf.

[0020]Further, since the tensile modulus of elasticity of the pile is 150 to 350 N / mm2, the durability of the pile is good. A tensile modulus of elasticity of less than 150 N / mm2 is not preferred because when the tensile modulus of elasticity is less than 150 N / mm, elastic force will be weak; the pile is liable to be cut; and the processability will be reduced. Conversely, a tensile modulus of elasticity of more than 350 N / mm2 is not preferred because when the tensile modulus of elasticity is more than 350 N / mm2, the rigidity will be increased, thereby being liable to have a bending habit or cause buckling and impairing flexibility as an artificial turf.

Problems solved by technology

Incidentally, since the surface of the artificial turf is loaded with various shoes, such as sports shoes with a rubber sole and spikes for various sports, the piles are liable to wear due to friction with various soles and be twisted or broken by repeated loads with the increase in the operating ratio, causing the tip of the pile to be fibrillated (to form fibrils).

However, unlike the destructive structure in which conventional artificial turf containing sand is fibrillated, the fibrillation of the long pile artificial turf occurs when the long, projected piles are repeatedly trampled to undergo twisting stress, causing splitting and fracture starting from bending and buckling of the piles.

Further, when the operating ratio of the artificial turf is high, the turf tip will be torn with the progress of fibrillation, which may not only adversely affect playability but also cause discomfort due to the adhesion of the torn piles to clothes and shoes by static electricity.

Further, since the torn piles are carried outside the field, for example, the surroundings of a field have become dirty, causing a problem also for the keeper side.

On the other hand, the conventional piles have low durability, and it has been difficult to prevent the fibrillation as described above.

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