Patent Application
20190292731
The invention relates to artificial turf and methods for the manufacture of artificial turf infill.
Artificial turf or artificial grass is surface that is made up of fibers which is used to replace grass. The structure of the artificial turf is designed such that the artificial turf has an appearance which resembles grass. Typically artificial turf is used as a surface for sports such as soccer, American football, rugby, tennis, golf, for playing fields, or exercise fields. Furthermore artificial turf is frequently used for landscaping applications.
Artificial turf may be manufactured using techniques for manufacturing carpets. For example artificial turf fibers which have the appearance of grass blades may be tufted or attached to a backing. Often times artificial turf infill is placed between the artificial turf fibers. Artificial turf infill is a granular material that covers the bottom portion of the artificial turf fibers. The use of artificial turf infill may have a number of advantages. For example, artificial turf infill may help the artificial turf fibers stand up straight. Artificial turf infill may also absorb impact from walking or running and provide an experience similar to being on real turf. The artificial turf infill may also help to keep the artificial turf carpet flat and in place by weighting it down.
European Patent EP 2 206 833 A1 discloses a method for producing a particulate infill material for synthetic-grass structures envisages providing a mass of thermoplastic material with a filler consisting of coconut-based material and subjecting said mass of thermoplastic material with the filler consisting of coconut-based material to granulation so as to obtain the aforesaid particulate infill material. Preferentially, the thermoplastic material is in particulate form, and the coconut-based material is in particulate form (fibrous, ground and/or shredded). The mixture obtained by mixing the thermoplastic material and the coconut-based material is preferentially heated in order to bring about softening of the thermoplastic material with the corresponding formation of a matrix of thermoplastic material that incorporates the coconut-based material as filler.
The invention provides for a method of manufacturing artificial turf infill, a method of manufacturing artificial turf, and artificial turf in the independent claims. Embodiments are given in the dependent claims.
In one aspect the invention provides for a method of manufacturing artificial turf infill. The method comprises first providing a base composition comprising a natural fiber, a at least one first type of of pigment, and a fluid binding agent. The fluid binding agent comprises at least one type of polymer component. The natural fiber comprises any one of the following: hemp fiber, burlap fiber, sisal fiber, elephant grass, cotton, coconut fiber, and combinations thereof.
The at least one first type of of pigment may be an individual pigment or it may also be a combination or mixture of different pigments. For example, the at least one first type of pigment may be a green pigmentation used for coloring artificial turf infill that is a mixture of green, white, yellow, and black pigments.
In the next step the method further comprises mixing the base composition. The method further comprises adding water and a catalyst to the base composition during the mixing of the base composition to cure the fluid binding agent and the at least one first type of of pigment into a base coating of the natural fiber. The term “base” in base coating is intended as a label to identify the coating of the natural fiber. The term “base” as used herein is therefore not intended to have a specific meaning outside of its use as a label in the context of the coating of the natural fiber. Hence, a “base coating” as understood herein is a coating that may or may not form a base for one or more additional coatings.
This embodiment may be beneficial for a variety of reasons. In one aspect the method may be beneficial because it may provide for a means of partially coating the natural fiber. The natural fibers are able to absorb and desorb water. It may be beneficial before a sporting event or game to spray water onto the artificial turf infill for it to absorb water. As the sunlight or hot air heats the artificial turf infill it may then desorb or evaporate water keeping the surface of an artificial turf cool. The amount of time that the artificial turf infill is able to retain water may be controlled by only partially covering the artificial turf infill.
A further advantage may be that the base coating provides protection for the natural fiber and helps it hold together. This may provide for an artificial turf infill which lasts for a longer period. Another advantage may be that the pigment provides a more natural color for the artificial turf infill. For example a brown or a green color may be used. If the natural fibers are brown colored the inclusion of a green pigment may be beneficial in that the artificial turf infill has both brown and green color and therefore makes the resulting artificial turf look more realistic or lifelike.
Another advantage may be that the fluid binding agent may partially absorb into the natural fiber and provide for a very strong bond between the natural fiber and the base coating. The use of a fluid binding agent comprising at least one polymer component may be beneficial because it may provide for a flexible artificial turf infill which has lifelike and/or also shock absorbing properties which help to protect people or players using an artificial turf manufactured with an artificial turf infill.
The use of natural fibers, and hemp in particular, may additionally be advantageous over coconut fibers as hemp and other natural fibers may be less flammable. In some cases the hamp and other natural fiber may also absorb water better than coconut fibers do. The absorption of water by the natural fiber may be advantageous because the artificial turf can be sprayed with water before a game. The evaporation of water from the natural fibers may have a natural cooling effect and may help reduce the temperature of the artificial turf during a game which is played in sunlight.
The use of hemp may also be beneficial because hemp is naturally resistant to fungi in comparison with coconut fibers. Hemp also has the benefit of being very skin friendly. Hemp is less abrasive and/or prickly than many other natural fibers such as wood chips or coconut fibers.
The use of natural fibers, and hemp in particular, as an infill material may also be beneficial because it has superior damping and shock absorption properties. A player who falls on an artificial turf with an infill according to an embodiment may in some cases be less likely to be hurt than if the player fell on an artificial turf that had a predominantly coconut fiber based infill.
The use of natural fibers may also be beneficial because they have low thermal conductivities in comparison to, for example, rubber granulate. This may help to reduce how hot an artificial turf surface is when exposed to sunlight.
The method of manufacturing artificial turf infill may be part of a method for manufacturing artificial turf.
In another embodiment the natural fiber consists of any one of the following: hemp fiber, burlap fiber, sisal fiber, elephant grass, cotton, coconut fiber, and combinations thereof.
In another embodiment the natural fiber consists of any one of the following: hemp fiber, burlap fiber, and sisal fiber, and combinations thereof. The use of the hemp fiber, burlap fiber, and sisal fiber over other types of natural fibers may be beneficial because these fibers provide superior water absorption properties as well as an increased resistance to decay due to funguses.
In another embodiment, the method further comprises providing a subsequent composition comprising the natural fiber with the base coating, the at least one second type of pigment and the fluid binding agent. The method further comprises mixing the subsequent composition. The method further comprises adding water and the catalyst to the subsequent composition during the mixing of the subsequent composition to cure the fluid binding agent and the at least one second type of pigment into a subsequent coating of the natural fiber.
The at least one second type of pigment and the at least one first type of pigment may be identical or they may be different. If they are the same then the coating of the natural fiber will be of a uniform color. If the at least one second type of pigment and the at least one first type of pigments are different colors then the two colors can be chosen so that the resulting artificial turf infill has a more natural and earth like appearance.
The method further comprises providing the natural fiber with the subsequent coating as artificial turf infill.
The coating of the natural fiber in at least two steps as described above, may be beneficial because it may provide for better coating of the natural fiber For example, during the mixing of the base composition individual fibers of the natural fiber will touch and interact with each other as the base coating on each of the fibers forms. The physical contact between different natural fibers will however cause defects. By coating the natural fiber particles a second time with the subsequent coating, much higher coverage of the natural fiber can be achieved.
As an example, during the formation of the base coating or the subsequent coating the coverage is each only 90% of the surface of the natural fiber. After the base coating has been deposited, roughly 10% of each granule of the natural fiber would be uncoated. There would be small surface defects. Deposition of the subsequent coating would then also cover 90% of the surface. As the interaction between the fibers or particles of the natural fiber is essentially a random process, one can expect that 90% of the defects that were exposed after the deposition of the base coating are coated in this case. The result of doing two coatings is then an artificial turf infill that is 99% coated with only minor amounts of defects, where the natural fiber is not coated with either the base coating or the subsequent coating. This effect may be used to control how quickly water can evaporate from the natural fiber, and thus control how long the cooling effect of this evaporation will be active.
Improving the coverage of the natural fiber may be beneficial in several different situations. For example, it may be desirable to color the artificial turf infill the same or a similar color as fibers or tufts, which are used to manufacture an artificial turf carpet. This may provide a more realistic-looking play surface or playfield. Another advantage is that the elastomeric natural fiber may be better coated and may therefore have superior wear qualities or may even be better isolated from the environment.
In another embodiment the natural fiber comprises fibers with a length less than 5 mm long.
In another embodiment the natural fiber comprises fibers with a length less than 1.5 mm long.
In another embodiment the natural fiber comprises fibers with a length less than 2.5 mm long.
In another embodiment the curing of the base coating and the curing of the subsequent coating is a polymerization process. Within the claims, the term ‘cure’ or ‘curing’ may be replaced with polymerization.
In another embodiment the subsequent coating at least partially covers the base coating.
In another embodiment the base coating only partially covers the natural fiber.
In another embodiment the subsequent coating only partially covers the base coating.
In another embodiment the natural fiber with the base coating and the subsequent coating is re-coated at least one time by performing the following sequence. The first step in the sequence is provide a subsequent composition by adding at least one additive and the fluid binding agent to the natural fiber that has already been coated with the base coating and the subsequent coating. The next step in the sequence is to mix the subsequent composition. The next step in the sequence is to add water and the catalyst to the subsequent composition during the mixing of the subsequent composition to cure the fluid binding agent and the at least one additive into a further coating. The natural fiber with the further coating is provided then as the artificial turf infill. This embodiment may be beneficial because an additional functional coating or layer may be put on the natural fiber. If the at least one first and/or second type of pigment is used again then the natural fiber may be coated a third or more times to improve the coverage and the coating of the natural fiber. Again, this effect may be used to control how quickly water can evaporate from the natural fiber, and thus control how long the cooling effect of this evaporation will be active.
This embodiment may also be beneficial because it may enable the deposition of so-called functional layers or additives, which may add to the utility or wear or usefulness of the artificial turf infill.
In another embodiment the PU catalyst is partially or completely water soluble and is one of the group: secondary amine, tertiary amine, a metal organic catalyst.
Utilization of these catalysts can facilitate production of coatings having openings that expose the natural fiber. In addition, coatings made using these catalysts can have structural integrity and/or durability, and/or mechanical properties which are compatible with the requirements for artificial turf infill.
Moreover control of a quantity of these catalysts can provide for a control of a number and/or size of the openings. As it is mentioned above and further in the text the openings in their own turn can provide for proper absorption and desorption of water from the surface of the fiber opened to air in the openings. At it is mentioned above the processes of water absorption and desorption of water can facilitate keeping the artificial turf infill and as a consequence the artificial turf cool.
In another embodiment the liquid PU component is based on an NCO terminal polymer which might be a pre-polymer, a polymeric isocyanate, an oligomeric isocyanate, a monomer and a mixture hereof.
In another embodiment the liquid PU component is based on an aromatic diisocyanate of the group toluene diisocyanate and/or 2,2′-Methylene diphenyl diisocyanate and/or 2,4′-Methylene diphenyl diisocyanate and/or 4,4′-Methylene diphenyl diisocyanate.
In another embodiment the liquid PU component is based on an aliphatic diisocyanate of the group hexamethylene diisocyanate, isophorone diisocyanate and 1,4-cyclohexyldiisocyanate.
In preferred embodiment the liquid PU component is based on methylene diphenyl diisocyanate (MDI) isomer mixture.
In another embodiment the hydroxyl component for the production of the PU is out of the group polyether polyol or polyester polyol.
In another embodiment the hydroxyl component is based on a polyetherpolyol of the molecular weight 500 to 10000. In a preferred embodiment the polyetherpolyol has a molecular weight of 1500-6000. In a very preferred embodiment the molecular weight is in the range of 2000-4000.
In another embodiment the at least one additive comprises the at least one first and/or second type of pigment.
In another embodiment the at least one additive further comprises a flame retardant like aluminum trihydrate, magnesium hydroxide turning a by itself burnable or flammable elastomeric material into a flame retardant infill material.
In another embodiment this flame retardant additives creates an intumescent coating and is based on intumescent component comprising ammonium polyphosphate or exfoliated graphite or a mixture hereof.
In another embodiment the at least one additive further comprises zeolite. The addition of zeolite may be beneficial because then the surface of the artificial turf infill may be able to absorb or de-absorb water. For example before a football game, which is scheduled to be held in the sun or in hot conditions, water may be sprayed onto the artificial turf and the zeolite may absorb an amount of water. As the sun or hot air heats the artificial turf infill during the game, the evaporation of water may cool the playing surface for the players and make the use of the artificial turf more pleasant.
In another embodiment the at least one additive further comprises methylcellulose, which may be beneficial in a similar way like zeolite for absorbing and desorbing of water, rendering a cooling effect at hot climatic conditions.
In another embodiment the at least one additive further comprises an antibacterial agent.
In another embodiment the at least one additive further comprises silver. Silver may be beneficial as an antibacterial agent.
In another embodiment the at least one additive further comprises chitosan, showing natural antibacterial properties.
In another embodiment the at least one additive further comprises an IR reflective pigment. The use of the IR reflective pigments as mixed metal oxides may be beneficial because it may reflect infrared light. This may reduce the heating of the artificial turf infill. A specific advantage may be that in this case the comparably expensive and precious pigments are merely on the surface of the infill natural fibers.
In another embodiment the at least one first and/or second type of pigment comprises an inorganic pigment, an organic pigment or mixtures thereof.
In another embodiment the at least one first and/or second type of pigment comprises any one of the following: iron oxide, iron oxide hydroxide, chromium(III) oxide, a copper Phthalocyanine pigment, a nickel azopigment, titanium oxide and combinations thereof.
In another embodiment the at least one type of additive is hindered amine light stabilizer (HALS) which is able to protect the PU coating as well as the elastic and/or compression resilient natural fiber against UV degradation.
In another embodiment the at least one type of additive is a thermostabilizing agent, protecting the elastic and/or compression resilient natural fiber against thermal degradation.
In another embodiment the at least one type of additive is an anti-freeze/deicing additive of the group: sodium chloride, potassium chloride, calcium chloride, sodium formate, potassium formate or a mixture hereof. The additive is migrating into the neighborhood of the natural fiber and by this inhibits the formation of ice by freezing humidity between the infill natural fiber particles.
In another embodiment the fluid binding agent further comprises any one of the following: a surfactant, a polyurethane aliphatic isocyanate, a polyurethane aromatic isocyanate, zeolite, an antibacterial agent, silver, IR reflective pigment, and combinations thereof.
In another embodiment the polymer component comprises any one of the following: at least one type of monomer, at least one type of partially polymerized polymer, and combinations thereof.
In another embodiment the polymer component is cured into at least one type of polyurethane by the water and the catalyst.
For example the polymer component could be methylene diphenyl diisocyanate. The polymer component could also comprise polyols.
In another embodiment the catalyst comprises any one of the following: an amine catalyst and a metal organic catalyst.
In another embodiment the method further comprises drying the subsequent composition before providing the natural fiber as the artificial turf infill.
It may also be possible to dry the base composition after coating the natural fiber with the base coating; however, it is not necessary. The water, which is leftover from the formation of the base coating on the elastic and/or compression resilient natural fiber may be used in the reaction of the subsequent composition.
In another embodiment the method is at least partially performed in a flow reactor. In the flow reactor the natural fiber is slowly moved along a linear sequential path, where the natural fibers are generally mixed and moved along. The benefit of using a flow reactor is that the artificial turf infill may be produced on a continuous basis.
In another embodiment the method is at least partially performed as a batch process. The base coating is formed on the natural fiber during an initial or base batch and the subsequent coating is formed on the natural fiber during a subsequent batch. Forming the base coating and the subsequent coating in separate batches may be beneficial because it may enable precise control over the formation of the base and subsequent coatings.
In another aspect the invention provides for a method of manufacturing artificial turf. The method comprises installing an artificial turf carpet. The artificial turf carpet comprises multiple artificial turf fiber tufts. For example, the artificial turf carpet may be a tufted artificial turf carpet. There may be a backing which has tufts of artificial grass fibers tufted into it. The method further comprises providing the artificial turf by spreading a layer of artificial turf infill between the multiple artificial turf fiber tufts. The artificial turf infill comprises a natural fiber. The natural fiber comprises at least two outer coatings. Each of the two outer coatings comprises at least one first and/or second type of pigment and a binding agent. The binding agent comprises at least one type of polyurethane polymer. This method may be beneficial because the artificial turf infill may be more completely covered with the two outer coatings. This may for instance provide superior optical appearance of the artificial turf infill. It may also provide better wear and longevity of the artificial turf infill.
In another aspect the invention provides for artificial turf infill. The artificial turf comprises natural fiber. The natural fiber comprises any one of the following: hemp fiber, burlap fiber, sisal fiber, and combinations thereof. The natural fiber comprises at least one outer coating. The at least one outer coating comprises at least one first type of pigment and a binding agent. The binding agent comprises at least one type of polyurethane polymer. The at least one outer coating comprises openings that expose the natural fiber.
Utilization of the binging agent comprising at least one type of the polyurethane polymer can be advantageous because it can provide the coating with openings which has structural integrity and/or durability, and/or mechanical properties which are compatible with the requirements for artificial turf infill. Moreover the openings can provide for the cooling effect of the artificial turf infill mentioned above and further in the text.
In another embodiment the natural fiber consists of any one of the following: hemp fiber, burlap fiber, sisal fiber, and combinations thereof.
In another aspect the invention provides for an artificial turf. The artificial turf comprises an artificial turf carpet. The artificial turf carpet comprises multiple artificial turf fiber tufts. The artificial turf further comprises the artificial turf infill according to an embodiment. The artificial turf infill is distributed between the artificial turf fiber tufts.
In another embodiment the artificial turf further comprises a sprinkler system. The use of a sprinkler system with the artificial turf may be beneficial because it may be used to automatically wet the artificial turf infill. For example this may be a convenient means of watering the artificial turf during a half time so that the artificial turf can be kept cooler during game play.
It is understood that one or more of the aforementioned embodiments of the invention may be combined as long as the combined embodiments are not mutually exclusive.
In the following embodiments of the invention are explained in greater detail, by way of example only, making reference to the drawings in which:
Like numbered elements in these figures are either equivalent elements or perform the same function. Elements which have been discussed previously will not necessarily be discussed in later figures if the function is equivalent.
Such an iterative processing of applying coatings can provide for an effective control of a number of openings and/or areas of the openings. In addition this iterative process can provide for a production of an integral coating of the artificial turf infill which has desired mechanical and/or structural properties and/or required wear and longevity.
The apparatus depicted in
As the base composition 1220 is transported further along the flow reactor 1200 fluid binding agent and at least one pigment cure into the outer coating 502 such as depicted in
In some examples the flow reactor may additional inlets so that additional layers or coatings can be applied.
The subsequent composition 1222 is mixed and transported underneath the second inlet for water and catalyst 1216. The water and catalyst are then mixed with the subsequent composition 1222 and over time are further transported to the end of the flow reactor 1220. By the time the subsequent composition 1222 has reached the end of the flow reactor 1200 the subsequent coating 600 has formed on the natural fibers 500. At the very end, then the artificial turf infill 202′ exits the flow reactor 1200 at an outlet 1217. The the natural fiber 500 is then artificial turf infill 202′. The artificial turf infill 202′ is then shown as entering into an optional dryer 1218.
It is clear from
| Number | Date | Country | Kind |
|---|---|---|---|
| 16181508.9 | Jul 2016 | EP | regional |
| 16204500.9 | Dec 2016 | EP | regional |
| 16204504.1 | Dec 2016 | EP | regional |
| 16207159.1 | Dec 2016 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/068546 | 7/21/2017 | WO | 00 |
