JP7296988B2 - Infill material for synthetic turf and synthetic turf obtained therefrom - Google Patents

Description

The present invention relates to infill materials for synthetic turf and synthetic turf obtained by using such infill materials.

Further, the present invention relates to methods for making such synthetic grass.

As is known, synthetic turf essentially consists of a mat made of plastic material to which blades of synthetic material, also called "bristles", are fixed to form the synthetic turf. Braids made of synthetic material are woven into mats by known processes that allow obtaining cambers of the blades that are close together if desired.

A filler material, also simply referred to as "filler", is dispersed all around the blade made of synthetic material. This is usually granular and is chosen depending on the type of sport for which the synthetic turf is intended (e.g. soccer, hockey, cricket, rugby), but occurs more frequently where the synthetic turf is installed. It is also selected according to weather conditions.

As is well known, infill materials provide drainage action by regulating the drainage of rainwater or irrigation water, protect the mats which guarantees synthetic turf for a long time, and give turf in particular the characteristics typical of natural turf. Give mechanical, physical and technical characteristics.

The most important characteristics of the filling material are, among others, the resilience of the user's ground, the rebound of the ball, the ability to absorb impacts when falling, the tensile and torque resistance to the forces induced by the shoe, compression, resistance to penetration of foreign objects, and the ability to absorb and drain water in the event of weather and environmental events.

The drainage action of synthetic turf is usually carried out by a base portion, or "stabilizing infill", which consists essentially of sand. Instead, the resilience of synthetic turf is ensured by the presence of rubber granules, or "performance fillers", which are usually concentrated in the upper part of the turf. Examples of similar filler materials are disclosed in US2002/081399.

However, known types of synthetic turf, including rubber and sand, have many drawbacks. First, compaction due to trampling or sedimentation of permeated drainage tends to eventually compact the sand layer and lose its drainage properties. As a result, synthetic turf cannot drain rainwater and suffers from waterlogging, especially when rainfall is heavy. This leads to random and turbulent mixing of the packing material, especially in its upper layers, and thus to a shift from its correct position in the packing. In particular, the filling material provides a zone in which the water-drawn material concentrates in time and, alternatively, other zones which are depleted entirely or, however, of the same material. Synthetic turf therefore loses its original structure and correspondingly loses the physical, mechanical and drainage functions it had at the time of installation.

Another drawback of prior art synthetic turf is closely related to the presence of rubber. In particular, the presence of rubber rapidly heats up, not only when it is most often derived from waste materials such as pulverized used tyres, but also when it is primarily rubber synthesized first during the hotter months. Build-up and temperatures above 55°C create problems for athletes when compared to natural grass fields. Synthetic turf comprising elastomeric materials therefore needs to be irrigated regularly in order to avoid as much time and water wastage as possible due to overheating of said synthetic turf. Furthermore, the irrigation and drainage cycles of the fill disclosed above tend to compact the sand layer over time, thus providing less effective drainage, as explained above.

In addition to the above, rubber has a tendency to crumble over time and thus the resulting debris clogs the empty spaces in the sand bed, thus reducing the effectiveness of drainage in the stabilizing packing. embossed.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a filling material for synthetic turf which is of high performance and can solve the above-mentioned drawbacks of prior art filling materials.

In particular, it is an object of the present invention to provide a filling material for synthetic turf which is able to maintain in time the structure it had at the time of laying.

Furthermore, it is an object of the present invention to provide a filling material for synthetic turf that is capable of effective drainage.

These and other objects are, according to the invention, a filling material for synthetic turf comprising:
- a stabilizing filling comprising a predetermined amount per unit surface area of vegetable material of rachis of cereal ear not coated with a film or layer of coating material, the stabilizing filling, wherein the predetermined amount of is set between 2 kg/m ² and 15 kg/m ² ;
- a performance filling positioned above said stabilizing filling and composed of a polymeric material having elastomeric properties in a predetermined amount per unit surface area in granular form; be.

As will be discussed in detail below, the presence of grain cobs in the stabilizing infill makes it possible to avoid the above-mentioned drawbacks of prior art synthetic grasses. Materials composed of cereal cobs, preferably maize corn cobs, in particular "swell" large amounts of water and then in the drier and hotter seasons transfer the absorbed moisture to the surrounding environment. It has the property of being released into the environment. As a result, as predicted above, when climatic conditions return to drier conditions and ambient temperatures rise, water or moisture is absorbed in excess by releasing moisture, increasing its volume and then gradually decreasing So the cob of a grain cob acts as a "lung" for the synthetic grass that incorporates it. The cob of the grain ear actually provides a high degree of porosity and is subjected to alternating cycles of expansion and compression, or volume reduction in each case. Thus, the filling material as a whole, and the performance filling in particular, is subjected to a decompression action that allows the filling material to continue to be cultivated and the physical properties of the filling to remain substantially intact in time. . In addition to the above, materials composed of cereal cobs, especially maize cobs, absorb large amounts of moisture, for example during rain and irrigation interventions, and then release said moisture during hotter seasons. can thus obtain a thermal balance of the turf. In particular, the water absorption capacity of corn cob is about 138%. Such properties avoid excessive heating of the performance filling during hotter seasons, especially of the above plastic materials with elastomeric properties.

Other features of the invention are defined in the dependent claims.

Advantageously, the stabilizing filling further comprises a predetermined amount per unit surface area of sand.

In particular, the stabilizing filling can provide a mixture of a predetermined volume percent of plant material of the cob of the grain and a predetermined volume percent of sand.

More specifically, the mixture of grain cob plant material and sand has the following composition:
- 25% to 90% by volume of grain cobs of the above materials,
- 10% to 75% sand by volume.

In particular, the filling material can contain a predetermined amount per unit surface area of the above mixture, said predetermined amount per unit surface area being set between 2.5 kg/m ² and 15 kg/m ² .

Preferably, the plant material composed of the cob of a cereal cob is a corn cob, ie a maize cob. This solution is based on the fact that the corn cob, i.e. the cob of maize, has a size that is usually larger than the cob size of other grains, and therefore particularly in terms of its ability to expand and reduce in size compared to other grains. It is particularly advantageous because it has better physical properties.

In one embodiment of the invention, the stabilized filling of filling material comprises:
- a first layer of sand;
- a second layer positioned on said first layer of sand and composed of said cereal cob plant material.

In particular, the first layer can consist of a predetermined amount per unit surface area of sand, which is set between 10 kg/m ² and 25 kg/m ² .

More specifically, the second layer can be composed of a predetermined amount of plant material per unit surface area of the cob of the grain, said predetermined amount per unit surface area being 2 kg/ It is set between m ² and 5 kg/m ² .

Advantageously, the above plastic materials with elastomeric properties in the granular form of performance fillers are styrene-butadiene rubber, or "SBR", thermoplastic materials, ethylene-propylene-diene monomers, or rubbers "EPDM", polychlorinated is selected from the group consisting of vinyl, or "PVC", synthetic organic materials, or combinations thereof;

In particular, the synthetic organic material mentioned above is a mixture of a plastic material with elastomeric properties and an organic material of plant origin, preferably selected from the group consisting of coconut and cellulose.

Advantageously, the plant material composed of cereal cobs, in particular maize cobs, has a particle size distribution set between 0.3 mm and 5.0 mm.

In particular, the term "sand" is to be understood as materials having a mineralogical composition, such as siliceous sands, pumice sands, lapilli sands, zeolites, vermiculites and the like.

In another alternative embodiment of the invention, the performance filling may consist only of grain cob cob plant material in a predetermined amount per unit surface area set between 2 kg/m ² and 8 kg/m ² .

Advantageously, the predetermined amount of filler material per unit surface area of polymeric material with elastomeric properties in granular form is set between 8 kg/m ² and 18 kg/m ² .

According to another aspect of the invention, the synthetic turf comprises:
- a mat comprising a first side and a second side opposite the first side;
- a plurality of blades made of synthetic material fixed to said mat, said blades made of synthetic material protruding from said second surface to form a synthetic turf;
- a filler material dispersed on said second side of said mat, as described above.

According to a further aspect of the invention, a method for making synthetic grass comprises:
- arranging a mat to which a plurality of blades made of synthetic material are fixed, the mat providing a first side and a second side opposite the first side, the plurality of is made of a synthetic material projecting from said second face;
- dispersing an infill material on said second side of said mat, thus obtaining a synthetic grass, said infill material comprising:
- a stabilizing filling comprising a predetermined amount per unit surface area of cereal cob plant material not coated with a film or layer of coating material, said predetermined amount per unit surface area being 2 kg/m Stabilizing packing, set at ² to 15 kg/m ² ,
- a performance fill positioned above said stabilizing fill and composed of a polymeric material having a predetermined amount of elastomeric properties per unit surface area;

In alternate embodiments, the blades made of synthetic material may include smooth blades, or wavy blades, or smooth blades alternating with wavy blades.

In particular, the mat may provide a plurality of holes arranged in communication with the first surface and the second surface to allow water to flow under the mat. .

According to another aspect of the present invention, a stabilized infill of infill material for synthetic turf comprises:
- 10% to 75% by volume sand;
- 25% to 90% by volume of grain cob plant material.

The invention will be illustrated using the following description of illustrative but non-limiting exemplary embodiments, with reference to the accompanying drawings.
1 schematically shows a cross-sectional view of a possible exemplary embodiment of a synthetic turf obtained using infill material according to the invention; Figure 2 schematically shows a cross-sectional view of an alternative embodiment of the synthetic turf of Figure 1; Schematically shows a cross-sectional view of a possible alternative embodiment of the synthetic turf of FIG. 1 schematically shows a cut-away front perspective view of a possible embodiment of a sack containing a mixture according to the invention, which can be used to make a stabilized packing; FIG. A schematic enlargement of the mixture contained within the sack of FIG. 4 is shown to highlight some features.

DETAILED DESCRIPTION OF SOME ILLUSTRATIVE EMBODIMENTS OF THE INVENTION With reference to FIG. a mat 2 providing a surface 2b opposite to the . The synthetic grass 1 further comprises a plurality of blades or bristles 3 made of synthetic material fixed to the mat 2, for example by gluing or stitching. Furthermore, on the face 2b of the mat 2 there is a filling material 10 arranged all around the blade 3 made of synthetic material.

The fill material 10 provides a lower portion or stabilization fill 11 positioned above the stabilization fill 11 and an upper portion or performance fill 12 . In all of the embodiments shown in the Figures and disclosed in detail below, the performance filler 12 is preferably made of styrene-butadiene rubber, or "SBR," thermoplastic materials, ethylene-propylene-diene monomer, or "EPDM consisting essentially of a plastic material having elastomeric properties selected between "rubber, polyvinyl chloride or "PVC", synthetic organic materials, or combinations thereof.

In particular, said synthetic organic material may be a plastic material having elastomeric properties, preferably a plant-derived organic material selected between coconut and cellulose, or a mixture of combinations thereof. The above mixture is suitably extruded to obtain granules of the above synthetic organic material.

More specifically, the above plastic materials with elastomeric properties in granular form can be black or different colors, or can provide mixtures of two or more colors.

According to the invention, the stabilizing filling 11 comprises, in a predetermined amount per unit surface area, the plant material of the cob of the grain that is not coated with a film or layer of coating material. In particular, said predetermined amount per unit surface area of the plant material of the cob of said grain is set between 2 kg/m ² and 15 kg/m ² , depending on the height of the synthetic grass. In a possible embodiment, the grain may be corn, and thus the cob of the grain is a "corn cob."

In particular, the plant material of the cob of the cereal grains, so as to be able to absorb and release moisture, thus avoiding excessive heating of the material constituting the performance filling, as disclosed above. It is not coated with a film of coating material to alternate the above-described cycles of volume increase and decrease which are basic.

In the embodiment of FIG. 1, the stabilizing filling 11 provides a single layer composed solely of the plant material of the cob of the grain. In this case, the dispersing step advantageously provides a predetermined amount per unit surface area of stabilizing packing set at 2 kg/m ² to 8 kg/m ² on the mat 2 described above. Thus, thanks to the above properties, in particular the ability to increase its volume in the presence of water and decrease its volume in drier climatic conditions, the cob material of the grain cob is a stabilizing filling. continue to cultivate, and perform an automatic decompression action that allows them to remain substantially intact in time and their physical characteristics, particularly their ability to drain.

In the embodiment of the invention of FIG. 2, the stabilizing filling 11 instead provides a lower layer of sand 11a, on top of which is a layer of grain cob material, preferably corn cob, as described above. 11b is positioned. As can be easily understood, the above-mentioned predetermined amount per unit surface area of sand of the stabilizing filling is mainly concentrated in this case in the first layer, i.e. the lower layer 11a, while in the grain ear. The above-mentioned predetermined amount of plant material per unit surface area, composed of stems, is mainly concentrated in the second layer, namely the top layer 11b. In this case, the cob material of the grain cob prevents the sand layer 11a and thus the entire stabilizing filling 11 and thus the synthetic turf from being compacted.

More precisely, the first layer 11a is composed of a predetermined amount of sand per unit surface area set between 10 kg/m ² and 25 kg/m ² . Alternatively, the second layer consists of a predetermined amount per unit surface area of the above-mentioned cereal cob cob plant material set between 2 kg/m ² and 5 kg/m ² .

In the alternative embodiment of FIG. 3, the filling material 10 instead consisted of a stabilizing filling 11, in this case a mixture of sand and the plant material described above, constituted of grain cobs. Provides a single layer. In particular, the mixture of the above grain cob plant material and sand has a volume percentage set between 25% and 90% of the grain cob material and between 10% and 75% of the sand. Consists of a set volume percentage.

More particularly, the predetermined amount per unit surface area of the mixture of grain cob plant material and sand is set between 2.5 kg/m ² and 15 kg/m ² .

By using a combination of sand and grain cob plant material, it is possible to obtain a synthetic turf with good drainage and thanks to the properties of the grain cob plant material, a stabilizing filling. Sand present in the material may be compacted, thus avoiding the possibility of flooding the synthetic turf after irrigation or rain. In other words, the presence of plant material in the cob of the grain ensures that, in time, the drainage effectiveness of the sand layer is maintained.

1-3, at the end of the filling material dispersion, the blades or bristles 3 of synthetic material project from the upper surface 10b of the filling material at a predetermined height, for example about 2-10 cm. provide part.

Further, as shown in detail in FIG. 3, the mat or support 2 provides drainage holes 4 sized to allow the outflow of permeate obtained by the drainage action of the stabilizing packing 11. can be done. FIG. 4 shows, by way of example, a sack 100 containing a predetermined amount of a mixture 20 of sand and grain cob plant material in the volume percentages disclosed above. As shown in detail in FIG. 5, the mixture 20 is said to have granules of the two components, i.e. sand and grain cob plant material granules, dispersed among each other such that they are not readily visible to the naked eye. Substantially "homogeneous" in the sense. The mixture 20 can be used, among other things, to obtain the embodiment of the synthetic grass infill material 10 of FIG.

The foregoing description of exemplary embodiments of the invention will make the invention completely clear according to its conceptual point of view, so that others may apply their present knowledge to further study. Such embodiments may be modified and/or adapted for various uses without departing from the invention and such adaptations and modifications are therefore considered equivalents of the specific embodiments. It should be understood that it should be considered The means and materials for achieving different functions described herein may have different properties for this reason without departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and should not be regarded as limiting.

Claims (16)

A filler material (10) for synthetic grass (1), comprising:
- a stabilizing filling (11) composed of a predetermined amount of plant material per unit surface area of a cob of a cereal grain not coated with a film or layer of coating material;
- for a synthetic turf (1) comprising a performance filling (12) positioned above said stabilizing filling (11) and composed of polymeric material in particulate form in a predetermined amount per unit surface area. a filling material (10) of
wherein said predetermined amount per unit surface area of grain cob plant material not coated with a film or layer of coating material is set between 2 kg/m ² and 15 kg/m ² ,
Filling material (10), characterized in that said polymeric material has elastomeric properties. said stabilizing filling (11) being a mixture of said plant material of grain cobs and sand,
- 25% to 90% by volume of the above material of the cob of the grain ear,
- Infill material (10) per synthetic turf (1) according to claim 1, characterized in that it provides a mixture having a composition of - 10% by volume to 75% by volume of sand. characterized by containing a predetermined amount of the mixture per unit surface area of the plant material of the cob of the grain and sand, wherein the predetermined amount per unit surface area is 2.5 kg/m ² to 15 kg/m ^{2 .} Infill material (10) for synthetic turf (1) according to claim 2 , which is set to . The stabilizing filling is
- a first layer of sand (11a);
- a second layer (11b) positioned on said first layer (11a), said second layer (11b) being composed of said plant material of the cob of a cereal grain; An infill material (10) for a synthetic turf (1) according to claim 1 or claim 2, comprising: The first layer (11a) is composed of a predetermined amount of sand per unit surface area, and the predetermined amount per unit surface area is set to 10 kg/m ² to 25 kg/m ² . Infill material (10) per synthetic turf (1) according to 4. Claim wherein said second layer (11b) consists of a predetermined amount of said plant material per unit surface area of grain cobs set between 2 kg/m ² and 5 kg/m ^{2 .} Infill material (10) for synthetic grass (1) according to claim 4 or claim 5. The plastic material with elastomeric properties in granular form of said performance filler (12) is styrene-butadiene rubber or "SBR", thermoplastic material, ethylene-propylene-diene monomer or rubber "EPDM", polyvinyl chloride or "PVC". A filler material (10) for a synthetic turf (1) according to any of claims 1 to 6, selected from the group consisting of , a synthetic organic material, or a combination thereof. Filling for synthetic grass (1) according to claim 7, wherein the synthetic organic material is a mixture of a plastic material with elastomeric properties and a plant-derived organic material selected between coconut and cellulose. Materials (10). 2. The stabilizing filling according to claim 1, wherein the stabilizing filling consists only of a predetermined amount of the plant material per unit surface area set between 2 kg/m ² and 8 kg/m ² of grain cobs. infill material (10) for synthetic turf (1) of Synthetic turf according to any of the preceding claims, wherein said rachis of grain ears are corn cobs, ie maize rachis. Filler material (10) for (1). The synthetic grass according to any one of claims 1 to 10, wherein the predetermined amount per unit surface area of the polymeric material having elastomeric properties in granular form is set to 8 kg/m ² to 18 kg/m ² (1 ) filling material (10). Synthetic turf (1),
- a mat (2) comprising a first side (2a) and a second side (2b) opposite said first side (2a);
- a plurality of blades or bristles (3) made of synthetic material fixed to said mat (2) and protruding from said second surface (2b) so as to form synthetic turf. a plurality of blades or bristles (3) created;
- a synthetic grass ( 1). 13. Synthetic turf (1) according to claim 12, wherein said blades or bristles (3) of synthetic material present an upper portion projecting a predetermined height from the upper surface of said infill material (10). A synthetic grass (1) according to claim 13, wherein said blades or bristles (3) are configured to protrude from said upper surface of said performance filling (12) to a height set between 2 cm and 10 cm. . A method for making synthetic grass (1), comprising:
- arranging a mat (2) to which a plurality of blades made of synthetic material are fixed, said mat (2) being of a first side (2a) and of said first side (2b); providing an opposite second surface (2b), said plurality of blades or bristles (3) being made of a synthetic material protruding from said second surface (2b);
- dispersing an infill material (10) on said second side (2b) of said mat (2), thus obtaining a synthetic grass (1), said infill material (10) comprising:
- a stabilized filling (11) comprising a pre-determined amount of plant material per unit surface area of cereal cobs not coated with a film or layer of coating material, said pre-determined amount per unit surface area being , a stabilizing charge (11) set between 2 kg/m ² and 15 kg/m ² ,
- a synthetic turf (1) comprising a performance filling (12) positioned above said stabilizing filling (11) and composed of a polymeric material having elastomeric properties in granular form in a predetermined amount per unit surface area ). 1. A stabilizing infill for infill material for synthetic turf, said mixture of cereal cob plant material and sand not coated with a film or layer of coating material, said mixture comprising:
- 25% to 90% by volume of the above material of the cob of the grain ear,
a predetermined amount per unit surface area of cereal cob plant material not coated with a film or layer of coating material, comprising a mixture having a composition of 10% by volume to 75% by volume sand, , from 2 kg/m ² to 15 kg/m ² .

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