Synthetic grass with resilient granular top surface layer

Abstract

A synthetic grass assembly for installation on a supporting soil substrate includes a pile fabric with a flexible sheet backing and rows of upstanding synthetic ribbons representing grass blades, extending upwardly from an upper surface of the backing. An infill layer of two distinct graded courses of particulate material is disposed interstitially between the upstanding ribbons upon the upper surface of the backing and of a depth less than the length of the ribbons. A bottom course of intermixed hard sand and resilient rubber granules with substantially identical particle size distribution characteristics is installed upon the backing and a top course exclusively of resilient rubber granules is placed upon the bottom course.

Description

TECHNICAL FIELD [0001] The invention is directed to a synthetic grass with grass-like ribbons forming a lattice enmeshing a particulate infill having a bottom layer of equally sized sand and rubber granules, and a top layer of rubber granules only. BACKGROUND OF THE ART [0002] Maintenance of natural grass turf on athletic playing or landscaped areas is expensive, natural grass does not grow well within shaded enclosed stadiums and continuous heavy traffic wears out areas in the natural turf surface. Natural turf surfaces deteriorate under heavy use and exposed soil creates an undesirable accumulation of water and mud. Synthetic grasses therefore have been developed in order to reduce the expenses of maintaining heavily used athletic playing areas, to render playing surfaces more uniform, and increase the durability of the grass surface, especially where professional sports are involved. [0003] Synthetic grass is installed with a carpet-like pile fabric having a flexible backing laid...

AI Technical Summary

Benefits of technology

[0026] It is a further object of the invention to eliminate the sprayin

Problems solved by technology

Maintenance of natural grass turf on athletic playing or landscaped areas is expensive, natural grass does not grow well within shaded enclosed stadiums and continuous heavy traffic wears out areas in the natural turf surface.

Natural turf surfaces deteriorate under heavy use and exposed soil creates an undesirable accumulation of water and mud.

A number of disadvantages result from the use of a uniformly mixed granular infill as in the Haas system where hard sand particles and resilient rubber particles are mixed and blended in a uniform proportion throughout the depth of the infill.

However, in both the Haas and Tomarin systems, abrasive hard sand particles present in the top surface layer of infill causes problems where such as games of football, rugby, soccer, field hockey, baseball are played since players repeatedly fall down or are knocked down on the playing surface.

In the case of conventional soil, the soil and humus particles provide some natural resilience but the rebound is more gradual due to moisture, small particle size and relatively low natural resilience.

Over time, areas of continuous sand spray or ball impact will result in visible sand on the playing surface.

It is considered undesirable to have light colored sand visible in the synthetic grass surface and, especially when clouds of sand are visible on such impacts.

In addition, exposed sand granules are highly abrasive to the skin when players fall or slide on the top surface, and could irritate eyes, ears, nose and mouth when sprayed, inhaled or ingested.

A further disadvantage of conventional infills is that abrasive sand particles remain on the top surface of the synthetic grass and players on the surface who come in contact with the sand particles experience skin abrasion.

The larger sand particles remain at the top of the granular layer and large particles are highly abrasive to human skin relative to the smaller particles.

As a result, over time the abrasive nature of the synthetic system is increased and may result in particular areas of the playing surface which experience heavy traffic being more abrasive than other areas.

In addition, where a wide range of particle sizes is used, the smaller particles fill in the interstices between the larger particles and increase the degree of compaction.

When the infill is rained on or flooded, the air trapped by the lightweight rubber particles causes the rubber particles to float.

This is undesirable since the rubber may wash down a drain with the surface wate

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