Patent Application
20190338472
The present invention relates to an infill material for a synthetic turf comprising organic material of vegetable origin, and it also relates to synthetic turfs so obtained.
As well known, an artificial turf is essentially a mat of plastic material to which blades of synthetic material are connected in order to simulate a natural turf. The blades of synthetic material are knitted to the mat by means of known processes, in order to provide a warp of filaments, thick according to the needs. All around the blades of synthetic material an infill material is usually distributed, simply called infill, for example a layer of sand followed by a layer of granular synthetic or natural material.
According to the kind of sports and of the use to which the synthetic turf is destined, a suitable type of infill material is chosen (see for example Italian patent applications No. PI2001A000049 and No. PI2003A000036, in the name of the same applicant).
In particular, the infill material provides a draining action by adjusting the drainage of rainwater or of irrigation water; a protection of the mat; a high duration to the artificial turf; and especially gives to the turf mechanical, physic and technologic qualities typical of natural turfs.
Such qualities are, for example: the elasticity of the ground for the user, the rebound of the ball or other piece of equipment, capacity of absorption of the hits when falling down, tensile and torque resistance to the force caused by the shoe, resistance against compression and against penetration of external bodies, as well as capacity of absorption and drainage of water in case of rainfalls and irrigation.
For these reasons, the infill material of known type comprises a predetermined amount of sand, which is necessary for an effective drainage of the synthetic turf, and a predetermined amount of rubber material, usually granular, which gives to the synthetic turf the necessary physical and mechanical characteristics as above described, and, in particular, a high elasticity.
However, the rubber infill material used as above described is obtained mainly from waste material, such as ground spent tires, or in any case from a mixture of elastomers, and therefore it has a high content of toxic substances and potentially noxious both for the environment and for the people, such as heavy metals and solvents of various type.
Alternatively, granules of freshly prepared rubber are used in various chemical compositions, which are more expensive and in any case are difficult to dispose of at the end of the life of the turf in addition to a high cost.
The presence of such noxious substances in the rubber used as infill material represents, furthermore, an obstacle to dismantling spent synthetic turfs to be changed by a new synthetic turf.
Furthermore, the elastomeric material cannot retain much water and accumulate heat, such that in the hot seasons they create much more discomfort to the players than natural turfs.
JP2003034906 describes a synthetic turf comprising a support to which the artificial fibers are connected. Al around the artificial fibers an infill material is present. The infill comprises a lower layer consisting of rubber granules, in particular ground spent tires, and at least one upper layer of loose material. The loose material can be for example “chaff”, sawdust, or other material having a light color, in such a way that it can reflect the sun light and avoid, then, an excessive heating of the turf. is, therefore, necessary that the layer of granular material makes up the upper part of the infill material, i.e. the layer that is arranged above the layer of ground spent tires. This is obtained using a granular material having a specific weight set between 0.3 and 1.
However, also the turf described in JP2003034906 has the drawbacks, above described, of fields involving waste material, such as ground spent tires, or a mixture of synthetic elastomers.
Another drawback of the solution described in JP2003034906 is that the upper layer, since it is very light, can be easily blown away by the wind. During a sports match this could hamper the players action, since it is not possible during the match to keep wet the upper layer.
In EP0541844 a artificial soil is described that can be used as growth substrate for cultivation of plants, for example, in golf courses. The artificial soil is highly resistant to vermin and virus and allows then reducing the use of pesticides and chemical products, which are commonly used in the cultivations made in natural soils. More in detail, the artificial soil comprises a layer of gravel, a layer of sand, and a layer consisting of an artificial soil for cultivation of plants. The artificial soil comprises a ground of cultivation for mushrooms in a ratio set between 60% and 80% by weight, in addition to a plurality of components among which sand, coal, mineral ore and chaff.
In the document no reference is made to the use of the artificial soil for making synthetic turfs.
It is therefore a feature of the present invention to provide an infill material for synthetic turfs that has not, or presents in an limited amount, rubber granules, and has in any case a high elasticity.
It is another feature of the present invention to provide an infill material for synthetic turfs that is much more biodegradable with time and more easily disposed of with respect to the infill presently known, containing large percentage of rubber granules.
It is a further feature of the present invention to provide an infill material for synthetic turfs that is made up, prevailingly, or completely, of natural vegetable material and is at the same time imputrescible and then not attackable by bacteria.
It is a particular feature of the present invention to provide an infill material for synthetic turfs that is non-flammable.
It is, furthermore, a feature of the present invention to provide an infill material for synthetic turfs that has a low retention of water and then capable of adjusting normal outflow of water through the synthetic turf.
It is a further feature of the present invention to provide an infill material for synthetic turfs that avoids the risk for light components to be blown away by the wind, and then to avoid hampering players during sports matches.
It is a further feature of the present invention to provide an infill material for synthetic turfs that presents a high elasticity and then achieves a technical quality comparable and even higher than a synthetic infill which uses the rubber as infill material.
These and other features are accomplished with one exemplary infill material, according to the invention, for synthetic turfs whose main feature is that it comprises a mixture of:
Advantageously, the defibrated arboreus material which is resistant to microbial digestion is a loose final product from raw material based on coconut coir.
Alternatively, the defibrated arboreus material which is resistant to microbial digestion is obtained by sawdust wood obtained by a raw material with high content of lignin, in particular selected from the group comprised of:
In particular, the defibrated arboreus material which is resistant to microbial digestion, for example coir, in the presence of moisture creates a three-dimensional reticular structure that holds the lighter parts such as the cereal husks “trapping them” and avoiding that they can get free from the turf infill and scatter in the environment. This makes it possible to exploit fully the physical characteristics of the cereal husks, in particular its high elasticity, and to avoid at the same time that it can hamper players during sports matches. Furthermore, the cereal husks have a shell-like shape, which gives to the mixture a high void ratio.
The cereal husks, or chaff, is a by-product of cereals work and is formed by the bracts, or glumelle, which encircle the raw kernel after the threshing.
In particular, the cereal husks can be selected from the group comprised of:
Preferably, the cereal husks comprise rice husks, which have a high rate of elasticity against bending of the hulls. In particular, the cereal husks substantially lens-shaped comprising concave portions and convex portions with rather high concavity. For these particular morphological features the cereal husks, and, in particular, the rice husks, occupy a high volume, but have a high void ratio. Thus, on the one hand a high elasticity is achieved and on the other hand a high draining action is achieved by the mixture that contains them.
In particular, the cereal husks can be present in said mixture in a percent volume set between 1% and 15%.
Advantageously, the cereal husks present in said mixture in a percent volume set between 1% and 10%. For example, the percent volume of the cereal husks with respect to the overall volume of the mixture can be about the 6%.
In particular, the matrix consisting of the defibrated arboreus material which is resistant to microbial digestion is capable of keep a limited amount of cereal husks. More precisely, cereal husks higher than the 15-20% v/v are not held by the matrix with the above described drawbacks.
Advantageously, said mixture comprises, furthermore, a predetermined amount of a loose final product obtained from raw material based on ground cork. This way, mixing the ground cork to the cereal husks and to the defibrated arboreus material which is resistant to microbial digestion, the physical characteristics of the infill material are further improved. In particular, the presence of the cork increases further the elasticity of the synthetic turf and then of improving the athletes performances.
Advantageously, the infill material comprises, furthermore, a predetermined amount of sand.
For example, said mixture can comprise a predetermined amount of sand.
In an exemplary embodiment of the invention the infill material can comprise:
In particular, the layer of sand can be present in a volume set between 8% and 30% with respect to the total volume of the infill material.
In particular, the sand has a granulometry set between 0.4 mm and 2.0 mm.
In particular, the defibrated arboreus material which is resistant to microbial digestion is present in said mixture in a percent volume set between 40% and 95%, Advantageously between the 65% and 85% v/v.
In particular, the measured amount v/v of the cork present in the mixture of loose material of vegetable natural origin is set between 15% and 40% v/v, Advantageously, set between 20% and 35% v/v.
Advantageously, the mixture of loose material of vegetable natural origin has the following composition:
Preferably, the cereal husks have a moisture content set between 5% and 15%.
In particular, the loose final product from raw material based on coconut ground comprises the sole granular and fibrous part contained in the starting raw material based on coconut. For example, the granular and fibrous part can be obtained putting the raw material starting through a separation step of the granular and fibrous part from the powder in it present.
Advantageously, the granular and fibrous part contained in the starting loose product is separated by sieving the raw material based on coconut coir.
Preferably, the granular and fibrous part of coconut ground has a grain size larger than 500 micron (μm) for 90% by weight.
Advantageously, the sieving of the loose material is carried out by a sieving means selected from the group comprised of:
Advantageously, the granular and fibrous part has the following grain size:
According to another aspect of the invention, a synthetic turf for sports or recreational activities comprises:
Advantageously, the filaments of synthetic material knitted on said mat comprises:
In particular, the filaments of the first group of filaments protrude from the infill material about 10-15 mm.
The second group of filaments may have twisted shape in order to give higher support to the infill material.
According to a further aspect of the invention, a method for making a synthetic turf comprises the steps of:
In particular, the step of distributing said infill material comprising the steps of:
Advantageously, the layer of sand has a volume set between 5% and 55% with respect to the total volume of said infill material.
In an exemplary embodiment, the infill material can comprise, furthermore, a predetermined amount of sand mixed to the rice husks and/or to the cork and/or to the coconut coir.
The invention will be made clearer with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings in which:
figures from 2 to 4 show diagrammatically transversal cross sections of some exemplary embodiments of the infill material for synthetic turfs of
With reference to
According to the invention and as shown in
The cereal husks, and, in particular, the rice husks, have a high elasticity against bending of the hulls. More in detail, the cereal husks are substantially lens-shaped comprising concave portions and convex portions with rather high concavity. For these particular morphological features the cereal husks, and, in particular, the rice husks, occupy a high volume, but have a high void ratio. from which on the one hand a high elasticity derives and on the other hand a high draining action is achieved by the mixture that contains them.
The defibrated arboreus material which is resistant to microbial digestion can be, instead, a loose final product of raw material based on coir, or alternatively, a wood sawdust obtained from a raw material with high content of lignin, such as Teak sawdust, Mahogany sawdust, Iroko sawdust, or a combination thereof. In particular, the above described defibrated arboreus material which is resistant to microbial digestion, in the presence of moisture form a three-dimensional reticular structure that holds the lighter parts of infill material 10, in particular the cereal husks, “trapping them” and avoiding that they can get free from the turf infill and scatter in the environment. This makes it possible to exploit fully the physical characteristics of the cereal husks, in particular its high elasticity, and to avoid at the same time that it can hamper players during sports matches.
The infill material 10 can also comprise a predetermined amount of a loose final product from raw material based on ground cork. This way, mixing the ground cork to the cereal husks and to the defibrated arboreus material which is resistant to microbial digestion the physical characteristics of the infill material are further improved.
In an exemplary embodiment, the infill material 10 has a composition comprising between about 1% and about 15% v/v of cereal husks, between about 55% and 85% of raw material based on coconut ground and between about 20% and 35% of ground cork. The infill material 10 can comprise, furthermore, a predetermined amount of selected sand with controlled grain size, for example set between 0.4 mm and 2.0 mm.
In the exemplary embodiment shown in
In the exemplary embodiment of
For example, above the layer 11 of sand a layer of cork 15a is distributed, above which a layer of cereal husks 15b is made mixed to a loose product based on coconut. Furthermore, a further layer 15c can be provided comprising about exclusively a loose product based on coconut coir.
In the two exemplary embodiments above described the layer of sand 11 has draining function and is, furthermore, capable of adjusting the microclimate of the synthetic turf 1. The infill material 10 has, instead, mainly the function of adjusting the outflow and the drainage of the rainwater, or irrigation water, and to ensure a suitable rate of moisture of the playground.
As above described, the presence of the rice husks confers to the synthetic turf 1 appropriate physical and mechanical characteristics, necessary for the sports or recreational activities. The rice husks has, in fact, a high elasticity both if they are entire and fragmented. Furthermore, the rice husks ensure a correct drainage of water from the turf infill owing to a reduced water retention, allowing an adjustment of the outflow of water from the synthetic turf 1.
In a further exemplary embodiment shown in
As shown, for example in
The following are not limitative examples of the components of the infill material, according to the invention:
Furthermore, hereafter a table is indicated of a standard composition of infill material, according to the invention.
In particular, the composition of the infill material given in the table can be adjusted within the range indicated responsive to the type of weaving and of density of the filaments (tufting), of the fibers used for making the synthetic turf, as well as responsive to the environmental features and of the ground that bears the turf, providing a customized distribution of the three components.
The infill material can be subject to changes concerning the succession of layers of the material, or the possible mixing of two, or all the components. For each specific case of stratification and succession, or mixing, of the material in any case is preferable to respect the percentage by weight of each element as indicated in the table 1 relative to a standard infill material standard.
an infill for artificial soccer fields, comprising a layer of sand of about 8% v/v of siliceous sand and 92% of vegetable natural material.
The vegetable natural material comprises 6% rice husks, 22% ground cork and 72% coconut coir from which the powder part has been removed.
A similar composition, with about 6% of rice husks, about 22% ground cork and about 72% of coconut coir from which the powder part has been removed has been used successfully also with different proportions of sand from the above indicated range, and even without sand.
The foregoing description of a specific embodiment will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without parting from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment. The means and the materials to realize the different functions described herein could have a different nature without, for this reason, 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 not of limitation.
| Number | Date | Country | Kind |
|---|---|---|---|
| PI2009A000107 | Aug 2009 | IT | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13392643 | Mar 2012 | US |
| Child | 16517828 | US |
