FR3041365A1 - SOIL WITH MIXED STRUCTURE NATURAL TURF AND ARTIFICIAL TURF - Google Patents

Abstract

A floor, particularly for sporting purposes, of the type comprising elements in the form of fibers, strands, strips, filaments, or the like, made of elastically deformable synthetic material, characterized in that it comprises a sheet on which the strand elements are fixed, the sheet forming an armature, and the strands standing up, in a natural position at rest above the sheet. The tablecloth is a woven textile based on synthetic material. The soil also comprises natural grass, the synthetic strands on the one hand, and the grass of natural grass on the other, being mixed with each other. The sheet is made of a material allowing the roots of the natural grass to grow through the sheet to the base ground on which the sheet rests.

Description

SOIL WITH MIXED STRUCTURE NATURAL TURF AND ARTIFICIAL TURF

The present invention relates to a floor, particularly for sports use, and comprising a floor covering including elements in the form of fibers of synthetic material, elastically deformable, intended for sporting use, without being limited to this application. The invention also relates to a method for implementing and setting up such a floor.

Sports grounds, such as for example football and rugby, are generally formed from a natural turf, which has optimal use characteristics for the players, such as elasticity, cushioning for example. falls or the rebound of the ball. In addition, natural turf has a valued aesthetic appearance.

However, a sports floor in natural turf has drawbacks.

It is difficult and difficult to set up because it requires a thorough and delicate preparation of the soil.

In addition, maintenance of natural grass is time consuming and therefore expensive, including watering, mowing and amendment expenses.

Finally, despite all the care taken in the preparation and maintenance of the field, and in the selection and selection of the grass, the bad weather on the one hand and the strong mechanical constraints to which the turf is subjected by the players, on the other hand, that it can be quickly and deeply worn or damaged.

However, it is almost impossible to repair the damaged terrain during a football match or rugby.

It is therefore necessary to provide for periods of repair or regeneration of the natural turf that prohibit during this period any use with the resulting economic consequences.

In known manner, it has been proposed to produce sports floors from elements in the form of filament fibers, or the like, and tending to imitate or approach the properties and characteristics on the one hand and the appearance of on the other hand, natural grass.

If synthetic sports floors make it possible to overcome the difficulties or disadvantages of natural grass, they do not achieve exactly the desired characteristics of natural grass, and mentioned above as the elasticity, the cushioning for the falls, or the rebound of the ball.

In addition, the anchoring of the filaments / fibers in the soil is carried out in a known manner by so-called weighting materials such as sand or an elastic polymeric material. In addition to the cost of these materials, their implementation is relatively difficult.

Finally, synthetic turf has a less appreciated aesthetic appearance than that of natural grass.

The present invention aims to remedy this situation and proposes a synthetic grass-based floor, particularly for sports use, comprising synthetic fibers or filaments, and which has optimum anchoring characteristics of the fibers.

Furthermore, the invention relates to a soil particularly for sporting use, including the above floor covering, and enjoying the respective advantages of natural grass and artificial turf as mentioned above. To this end, according to the invention, the floor, particularly for sporting use, of the type comprising elements in the form of fibers, strands, strips, filaments, or the like, made of elastically deformable synthetic material, is characterized in that it comprises a sheet on which the strand elements are fixed, the sheet forming an armature, and the strands standing up, in a natural position at rest above the sheet.

In what follows, only the following will be used: - the term "strand" to denote the elements of fibers, filaments, strips, etc. the term "tablecloth", it being understood that those skilled in the art of sports floors also use the term "file".

Thus, the anchoring of the strands in the soil of the invention is reliable. The tablecloth forms an armature for the strands that are firmly attached to it.

The sheet is a woven fabric based on synthetic materials and preferably also natural. The sheet has a weight per unit area of between 100 and 350 g / m2 depending on the applications and uses.

The sheet has, in particular a thickness of 1 to 5 mm

The web is perforated with operculas or perforations, preferably rectangular, measuring approximately 3.0 ± 0.6 mm in length and 1.0 ± 0.6 mm in width.

The web is formed of either HDPE fiber (high density polyethylene) or HDPE fiber with cotton fibers.

According to another characteristic, the floor comprises, in addition to the floor covering comprising synthetic fibers, natural grass, the synthetic strands on the one hand, and the grass of natural grass on the other, being mixed with each other. other.

Thus, the soil of the invention has the advantageous combined characteristics of natural grass and synthetic grass.

According to another characteristic, the sheet is made of a material that allows the roots of the natural grass to grow through the sheet, towards the base ground on which the latter rests.

Preferably, said web consists at least in part of a biodegradable material.

Said sheet is advantageously made of a mixture of synthetic material, such as high-density polyethylene (HDPE), for a proportion of between 30 and 70%, and of natural material such as cotton in addition.

The strands are associated or attached to the web, by sewing, meshing, stapling, gluing, welding, or tufting.

Advantageously, the soil further comprises a layer, preferably deposited by coating, of synthetic or natural material, the function of which is to maintain the strands on the sheet, of the rubber or latex type, or polyurethane, covering the sheet with less on the face of the tablecloth opposed to the strands. The coating layer has a thickness that varies according to manufacturing tolerances, and is deposited only where the strands are anchored in the sheet so as not to affect the permeability of the sheet on the one hand and prevent the passage of the roots of the natural grass on the other hand. The latex coating is for example of a weight per unit area of 300 g / m2.

The height of the strands above the sheet is between 55 and 85 millimeters, and preferably between 60 and 70 millimeters.

The synthetic strands are arranged in clusters each comprising at least four strands (up to ten or twelve), the density of the clumps being between 5000 and 6500 (preferably of the order of 6000) tufts per m2.

Preferably, the tufts of strands are spaced a few millimeters apart from one another in two orthogonal directions. The invention also relates to a method for producing a floor, particularly for sports use, comprising the steps of: - preparing the ground by removal of the original turf, debris and leveling of the soil: - placement in the field of a substrate of a specific composition compatible with the weight layer of the extended layer then, and further establishment of means of drainage in the ground before placing the aquifer; - Spreading of the above floor covering, formed of a sheet associated with strands of synthetic material; - laying on the sheet, a layer of ballast, including a mixture of organic materials (including in particular zeolite) and sand, on a height between 5 and 90% of the height of the fibers, and preferably of the order of 50% of the height of the fibers; - Seeding said layer with natural grass; - Size and mowing of natural grass to a height exceeding the carpet formed by synthetic fibers, between 5 and 150 millimeters, and preferably between 10 and 70 millimeters. The invention will be better understood in the light of the description which follows, referring to an example embodiment, illustrative but not limiting, with reference to the indexed drawing in which:

Figure 1 is a sectional view along a vertical plane of a floor according to the invention;

Figure 2 is a perspective view from above showing the top and bottom of the web provided with synthetic fibers;

FIG. 3 is a diagram cut along the ply provided with fibers, in a vertical plane orthogonal to the section plane of FIG. 1;

Figure 4 illustrates a curve representative of the particle size of the soil sand of the invention.

In the following description the term "height", the qualifiers "superior", "lower", "high", "low", "tangential", "radial", "transverse", "distal", "before" "Rear" of an element of the device of the invention are used in the context of a normal installation of the latter, that is to say with respect to a horizontal ground.

With reference to FIG. 1, an embodiment of the coating floor of the invention is described below, in an application of the latter to a sporting use such as football or rugby.

It is understood that the floor of the invention can be used for other purposes, such as for example: embankment, golf (near bunker area), leisure park, tramway, vehicle parking, etc.

Figure 1 is a schematic sectional view along a vertical plane of the ground of the invention based on the ground 1 on which are arranged the various elements of the soil.

On the surface 2 of the ground 1 is extended a sheet 3, forming a layer of thickness of about 1 to 5 mm, made of a synthetic material, such as for example high density polyethylene (HDPE), or for 100% or between 30 and 70% and preferably between 40 and 60% (or even more preferably 45/55%), the balance being formed of a biodegradable material, such as cotton.

The web 3 is formed of a mesh of woven polyethylene HD fibers.

The sheet 3 is made of a sufficiently rigid material to maintain a certain resistance in the field and flexible enough to be rolled in strips of width between 1 and 4 m and length between 20 and 100 m according to the uses of the ground. The strips are laid adjacent (edge to edge) to cover the ground 1. The strips may be possibly assembled together edge by board by any known means.

The sheet 3 must allow to pass the water (rain) passing through the weighting layer extended on the sheet, as described below, and let the roots of natural grass. It is provided for this purpose perforations, for example rectangular, about 3.0 ± 0.6 mm in length and 1.0 ± 0.6 mm in width.

On the web 3 are attached strands bearing the generic reference 4, synthetic material such as HD polyethylene. The strands 4 are associated with the sheet by the so-called tufting process.

The strands are of elastically deformable material.

The sheet 3 forms a kind of reinforcement for the strands.

The strands are grouped in tufts of four to ten strands, which rise, in natural position above the sheet 3 to a height h1 between 40 and 70 mm depending on the applications and uses of the soil once completed.

The strands are fixed on the sheet 3 as follows, according to the embodiment of Figures 1 to 3.

The strands are grouped in bundles of four to ten, preferably six, parallel strands, and having substantially the same total length between 80 and 150 mm.

In particular with reference to FIG. 3, the strands grouped in bundle (by 4 to 10) are then passed together through the mesh of the sheet, through a first perforation 5 made in the sheet, and then ironed again through of the sheet 3, through a second perforation 6, made at a distance of between 1 and 5 mm from the first.

The result is the representation of FIG. 3, in which: the bundle 4 of four to ten bundled strands forms two tufts 4A and 4B, parallel and spaced a few mm apart, and protruding from the so-called upper surface 3A of the sheet 3 ( surface 3A is intended to be turned upwards); - Each tuft 4A, 4B is formed from four to ten strands substantially parallel and substantially orthogonal to the plane of the web; - The part of the bundle of strands, located on the side of the lower surface 3B of the web, forms a loop 4C of a few mm between the adjacent perforations 5 and 6.

The sheet is made in the form of a strip or rolls 1 to 4 m wide and 20 to 100 m long.

Figure 2 shows a portion of a web strip 3 laid on the ground 1, and returned in part only for ease of understanding, thus showing the tufts of strands on the upper surface and part of the lower face of the web.

Thus lines 7, 8, 9 parallel aligned tufts are formed on the upper surface 3A of the web 3. The spacing between the lines is of the order of 2 to 8 cm As an indication, the density of tufts of strands is between 5000 and 6500 tufts per m2. The surface density of the strands is of the order of 70000 / m2.

The tufts of synthetic strands are spaced from each other by a distance of between 5 and 30 mm in all directions (longitudinal of the strip or roll of web, diagonally).

The sheet 3 is coated with rubber-like material or latex or the like, at the crossing points of the strands in the sheet, at least on its underside 3B, namely the face of the sheet opposite that from which the tufts of strands exceed , and thus intended to rest on the base ground 1.

Referring again to Figure 1, the soil further comprises, spread over the web 3, through tufts of strands, a weighting layer 10, including a mixture of organic matter and sand.

The sand preferably has a pass close to 100% at 630 pm.

In one example, the particle size is given according to the curve of FIG.

Sand meets the following criteria: - resistance to compaction; - drainage capacity (permeability); - installation and passage of natural grass roots;

The sand has: • Total porosity: 35 to 50% • Porosity in air: 5 to 30% • Porosity in water: 15 to 25%

The rate of infiltration of water must be in accordance with the norm of construction of natural grass play areas for a so-called developed substrate (in the sense of standard NF P90-113-October 2008).

The sand is chosen so as to avoid any migration of the fine elements of the sand under the sheet.

Sand is added organic matter and zeolite®, which aim to: • Limit the leaching of fertilizers by improving their retention in the soil • Improve the nutrition of natural grass by promoting balances and exchanges between minerals • Promote the installation of a microbial life, especially in the rhizosphere • Allow the rapid degradation of senescent or dead organic compounds and thus reduce the felting • Increase the air capacity and the oxygenation of the turf in a persistent wet condition

The organic matter content is about 1%, in order to prevent the reduction with time of the porosity.

Organic materials must have an advanced degree of ripening and be very stable.

Preferably: - The organic matter content is high relative to the raw material - The product is well humidified and stable, having a C / N ratio close to the range between 8 and 12 and a biochemical stability index (BSI) 2 greater than 60.

The particle size of organic matter corresponds to that of sand.

Finally, zeolite, of particle size 0/3 mm, is added.

The ballast layer 10 has a height h2 between 5 and 90% of the height of the strands, and preferably of the order of 50% of the height h1 of the tufts 4A and 4B strands.

The layer 10 forms a weighting layer of the sheet and associated strands, to ensure its stable maintenance on the base ground 1.

Finally, the soil comprises natural turf comprising tufts 11 of strands 12 of natural grass, whose roots 13 firstly grow in the ballast layer 10, then cross the sheet 3, and then develop in the base course 1.

The root development of natural grass is allowed by the presence of perforations made evenly distributed over the sheet. The perforations are rectangle-shaped and are spaced about 0.5 to 3 mm apart from each other.

The tablecloth is thus perforated.

The tufts 4A, 4B of synthetic strands on the one hand, and the tufts 11 of grass of the natural grass on the other hand, are mixed with each other.

The natural grass exceeds synthetic strands 4 with a height h3 of between 5 and 150 millimeters, and preferably between 10 and 70 millimeters.

The soil of the invention, which provides secure anchoring of the synthetic strands, further combines the advantageous combined characteristics of natural grass and synthetic turf.

In particular: - resistance - stability - game characteristics - protection by the synthetic strands of natural grass growth in the first phase - permeability maintained - adaptability to any climate - adaptability to different uses.

The placing of the soil of the invention comprises the steps of: - preparation of the ground 1 by removing the original grass, debris and leveling the soil; - preparation (fertilizer in particular) of it to ensure the future development of the roots of natural grass, over a height h4 of about 30 mm; spreading on the base ground 1, prepared, the web 3 associated with the tufts 4A, 4B of synthetic fibers; sowing natural grass on the upper surface of the weighting layer; cutting and cutting natural grass 11 at a height h3 protruding from the carpet formed by the synthetic strands, between 5 and 150 millimeters, and preferably between 10 and 70 millimeters.

The method can be implemented to create a sports floor for example, or to renovate a sports floor natural grass or artificial turf at the origin.

Claims (11)

CLAIMS T Sol, particularly for sport use, of the type comprising elements in the form of fibers, strands, strips, filaments, or the like, made of elastically deformable synthetic material, characterized in that it comprises a sheet (3) on which are fixed the strand elements (4), the ply (3) forming an armature, and the strands (4) standing up, in a natural resting position above the ply (3). 2. Soi according to claim 1, characterized in that the web (3) is a woven textile based on synthetic material, 3. Floor according to one of claims 1 or 2, characterized in that it comprises, in addition to the floor covering comprising strands (4) of synthetic material, natural grass (12), synthetic strands (4) d on the one hand, and the grass of natural grass on the other, being mingled with each other. 4. Floor according to claim 3, characterized in that the sheet (3) is made of a material allowing the development of the roots (13) of the natural grass through the sheet (3), to the ground (1) base on which is the latter. 5. Floor according to one of claims 1 to 4, characterized in that said web (3) consists at least in part of a biodegradable material. 6. Floor according to one of claims 1 to 5, characterized in that the web (3) consists of a mixture of synthetic material, such as high density polyethylene (HDPE), for a proportion between 30 and 70 %, and of natural material such as cotton in addition 7. Floor according to one of claims 1 to 6, characterized in that the strands (4) are fixed on the sheet (3), by sewing, mesh, stapling, gluing, welding, tuftage. 8. Floor according to one of claims 1 to 7, characterized in that it further comprises a layer, preferably deposited by coating, synthetic material of the rubber or latex type, covering at least partially at least one face (3B ) of the web (3). 9. Floor according to one of claims 1 to 8, characterized in that the height (h1) of the strands (4) above the web (3) is between 55 and 85 millimeters, and preferably between 60 and 70 millimeters. 10. Floor according to one of claims 1 or 2, characterized in that the strands (4) synthetic are arranged in clusters (4A, 4B) each comprising at least four strands (4), the tuft density (4A, 4B) being between 5000 and 6500 tufts per m2. 11. A method for producing a floor, especially for sports use, comprising the steps of: - preparing the ground (1) by removing the original grass, debris and leveling the soil; - Spreading of the above floor covering, including firstly a web (3), and secondly strands (4) of synthetic material; - spreading, on the sheet (3), a ballast layer (10), including a mixture of soil and sand, over a height (h2) of between 5 and 90% of the height (h1) of the fibers, and preferably of the order of 50% of the height (h1) of the fibers; - seeding said natural grass layer (12); - Size and mowing of natural grass (12) at a height (h3) exceeding the carpet formed by synthetic fibers, between 5 and 150 millimeters, and preferably between 10 and 70 millimeters.