ARTIFICIAL TURF INFILL MATERIAL FOR DISINFECTING ARTIFICIAL TURFS

Abstract

A method of disinfecting an artificial turf structure includes applying to the artificial turf

Claims

1. A method of disinfecting an artificial turf structure, comprising: applying to the artificial turf structure a mixture of microporous zeolite mineral and at least one of copper and silver.

2. The method of claim 1, wherein the applying of the mixture comprises: applying the microporous zeolite mineral to the artificial turf structure; distributing of the copper and/or silver on the applied microporous zeolite mineral; exposing the mixture to water, thereby obtaining a copper and/or silver loaded zeolite.

3. The method of claim 1, the zeolite mineral having a size in the range [0.42 mm, 1.39 mm], or [0.59 mm, 1.39 mm], or [0.84 mm, 1.68 mm], or [0.18 mm, 0.25 mm].

4. The method of claim 1, wherein the mixture comprises a copper and/or silver loaded zeolite that is obtained before being applied to the artificial turf structure, wherein the obtaining of the mixture comprises: adding the copper and/or the silver to water, thereby obtaining a metal solution; mixing the metal solution with the microporous zeolite mineral, resulting in a mixture; drying the resulting mixture.

5. The method of claim 4, wherein the mixing is performed such that the microporous zeolite mineral adsorbs the metal solution in an amount of at least 40 to 50% of the metal solution.

6. The method of claim 4, wherein the metal solution and the microporous zeolite mineral are exposed to a predefined pressure, the method further comprising introducing the metal solution and the microporous zeolite mineral in an autoclave at the predefined pressure.

7. The method of claim 2, wherein the water is a demineralized water.

8. The method of claim 4, wherein the mixture is applied to the artificial turf structure in amount of 25 g/m.sup.2 to 2500 g/m.sup.2.

9. The method of claim 1, wherein the porosity of the zeolite mineral is about 10% to about 40%, preferably from about 10% to about 35%, wherein the specific surface area of the microporous zeolite mineral is between 25 m.sup.2/g and 40 m.sup.2/g.

10. The method of claim 1, wherein the microporous zeolite mineral has a selected grain size smaller than 1.5 mm and a porosity of about 15% to about 20%, wherein the grain size distribution of said microporous zeolite mineral is as follows: 70-90% of the grains have a size in the range of about 0. 4mm to about 1.5 mm and about 10% to about 30% of the grains have a grain size smaller than about 0.4 mm.

11. The method of claim 1, further comprising redistributing the copper and/or silver on the applied microporous zeolite mineral after a predefined time period and exposing the mixture of zeolite mineral and copper and/or silver to water.

12. The method of claim 1, wherein the mixture of microporous zeolite mineral and at least one of copper and silver further comprises an insect repellant compound and/or a fragrance.

13. A method for manufacturing an artificial turf with a disinfection capability, the method comprising: providing an artificial turf structure; applying a microporous zeolite mineral to the artificial turf structure; distributing of copper and/or silver on the applied microporous zeolite mineral; exposing the microporous zeolite mineral and the distributed copper and/or silver to water.

14. The method of claim 13, the microporous zeolite mineral being applied in the form of a mixture comprising a copper and/or silver loaded zeolite, the method further comprising: obtaining the mixture, the obtaining comprising exposing a metal solution and a microporous zeolite mineral to a predefined pressure.

15. The method of claim 14, the exposing of the metal solution and the microporous zeolite mineral to the predefined pressure comprising introducing the metal solution and the microporous zeolite mineral in an autoclave at the predefined pressure, the zeolite mineral having a granularity in the range [0.42 mm, 1.39 mm], or [0.59 mm, 1.39 mm], or [0.84 mm, 1.68 mm], or [0.18 mm, 0.25 mm].

16. An artificial turf infill material comprising a copper and/or silver loaded zeolite.

17. The infill material of claim 16, the zeolite having a selected gain size smaller than 1.5 mm and a porosity between 15% and 20%.

18. The infill material of claim 16, wherein the zeolite has a grain size distribution as follows: 70% to 90% of the grains have a size in the range [0.4 mm, 1.5 mm] and 10% to 30% of the grains have a size smaller than 0.4 mm.

19. The infill material of claim 16, wherein 0.6% of the zeolite at most is not retainable on a 100 mesh screen, the microporous zeolite mineral having a hardness between smaller than 3 or smaller than 4 on the Mohs scale and wherein the moisture level in the mineral is smaller than 6%.

20. The infill material of claim 16, the zeolite being further loaded with an insect repellant compound and/or a fragrance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0110] In the following embodiments of the invention are explained in greater detail, by way of example only, making reference to the drawings in which:

[0111] FIG. 1 is a flowchart of a method for disinfecting an artificial turf structure;

[0112] FIG. 2 is a flowchart of an example method for applying metal-loaded zeolite on the artificial turf structure;

[0113] FIG. 3 is a flowchart of a method for forming an artificial turf infill material;

[0114] FIG. 4 is a flowchart of an example method for selecting a microporous zeolite mineral from the zeolite ore;

[0115] FIG. 5 is a flowchart of another example method for selecting a microporous zeolite mineral from the zeolite ore;

[0116] FIG. 6A illustrates an example of an artificial turf;

[0117] FIG. 6B illustrates a further example of an artificial turf;

[0118] FIG. 6C illustrates a further example of an artificial turf; and

[0119] FIG. 7 illustrates an example of an artificial turf which incorporates a sprinkler system.

DETAILED DESCRIPTION

[0120] 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.

[0121] FIG. 1 is a flowchart of a method of disinfecting an artificial turf. In step 10, an artificial turf structure (such as artificial turf structure described with reference to FIGS. 6A-6C) is provided. In step 12, a mixture of microporous zeolite mineral and at least one of copper and silver may be applied to the artificial turf structure. The application of the mixture may for example be performed by first preparing the mixture and then applying or scattering it on the artificial turf structure.

[0122] The method of FIG. 1 enables, for example, a dry mixture of granules of zeolites and copper chloride. The dry elements containing zeolite and copper (e.g. in hydroxide form) and/or silver are mixed by applying both of them on the turf surface. After application of the dry elements of zeolite and copper/or silver, the elements are exposed to water e.g. of rains. This exposition to water may complete the mixture process as the copper and/or silver (being wet) may be loaded into (or adsorbed or absorbed by) the zeolite. The humidity generated by water (e.g. from the rains) may enable to form metal solution with the copper and/or silver.

[0123] For example, during a predefined time period the artificial turf surface may receive animal urines. This may cause cation exchange between the copper and the sodium ions of the urines, leading to a progressive release of the copper from the pores of the zeolite mineral. After the predefined time period, the zeolite mineral may lose at least part of the copper from the pores. After the time period, at least part of the method may be repeated to ensure that the disinfection capability of the artificial turf is maintained over time. For that, the zeolite mineral (that received the urines) may be left on the artificial turf and the copper and/or silver may be applied again to the existing zeolite mineral. The exposition of the applied elements to water may enable the copper and/or silver to enter the pores of the zeolite again as described above.

[0124] FIG. 2 is a flowchart of a method for applying the mixture of FIG. 1 on the artificial turf structure. In step 20, the copper and/or the silver may be added to or mixed with water, thereby obtaining a metal solution. In step 22, the metal solution is mixed with the microporous zeolite mineral, resulting in an aqueous mixture (e.g. in which the zeolite has adsorbed or absorbed at least part of the metal solution). In step 23, the aqueous mixture is dried.

[0125] As described with reference to FIG. 1, after the predefined time period, the zeolite mineral (resulting from the method of FIG. 2) may lose at least part of the copper from the pores. After the time period, the zeolite mineral (that received the urines) may be left on the artificial turf and the copper and/or silver to the existing zeolite mineral may be applied again. The exposition to water of the applied elements may enable the copper and/or silver to enter the pores of the zeolite again.

[0126] The microporous zeolite mineral of FIGS. 1 and 2 may for example be obtained or selected as described with reference to FIGS. 3 and 4.

[0127] FIG. 3 is a flowchart of a method for forming an artificial turf infill material. The infill material may be included in artificial turfs as described with reference to FIGS. 6A-6C.

[0128] In step 101, a zeolite ore may be provided. The zeolite ore is a naturally occurring solid material. The zeolite ore has a porosity between of 15% and 20%. The term porosity refers to the volume fraction of void space in a porous article. The zeolite phase of the zeolite ore may comprise one or more of the group consisting of clinoptilolite, mordenite, or other naturally occurring zeolite minerals.

[0129] The zeolite ore may be provided for example as follows. A zeolite deposit is stripped of overburden and stockpiled for use in subsequent mine reclamation. The resulting exposed ore body is drilled to depths between 12 and 14 feet. The drill holes are loaded with an explosive charge that degenerates upon use, leaving no residue in the zeolite ore. From the mine pit, the zeolite ore is hauled by dump truck to the crude ore stockpile at a processing mill.

[0130] In step 103, a microporous zeolite mineral may be selected from the zeolite ore. The selection may be performed using a selection criterion involving the specific surface area of the mineral. The selection criterion may refer to one or more rules on the specific surface area.

[0131] For example, the selection of step 103 comprises a selective recovering or obtaining of the microporous zeolite mineral having a predefined specific surface area from the zeolite ore. The specific surface area constitutes an important criterion that is involved in the determination of the quality of a zeolite mineral since the nature of the specific surface area enables a decisive characteristic for the overall usage of zeolite in numerous technical components and products. For example, a specific surface area which is too high may render the release of water under ambient temperature very slow or inexistent.

[0132] In one example, the selection criterion requires that the specific surface area is smaller than a predetermined maximum specific surface area. The maximum specific surface area of the mineral may for example be determined as the surface specific area that enables the water in the mineral to release, under an ambient temperature, at a predefined minimum rate. For example, for a specific surface area equal or higher than 40 m.sup.2/g the water may only release under temperatures which are higher than the maximum ambient temperatures. Those high temperatures require the use of an oven. The present method may be advantageous as the maximum surface specific area that is selected enables the water to release under ambient temperatures e.g. between 40 and 60 C. The selected specific surface area may for example be 20 m.sup.2/g for a porosity of 15% to 20%.

[0133] In another example, the maximum specific surface area is chosen such that at most 0.6% of the mineral is not retainable on a 100 mesh screen e.g. 94% of the mineral has a grain size higher than 0.15 mm. This may have the advantage of reducing the amount of dust in addition to enabling a progressive release of the water for an optimal cooling of the artificial turf. Reducing the amount of dust may be beneficial for improving the safety of the product as regards the protection of the respiratory system of users of the artificial turf.

[0134] The selected microporous zeolite mineral may be used as the artificial infill material.

[0135] In on example, the artificial infill material may consist of the selected microporous zeolite mineral. In another example, the artificial infill material may comprise the selected microporous zeolite mineral in addition to other infill materials.

[0136] FIG. 4 is a flowchart of an example method for selecting a microporous zeolite mineral from the zeolite ore (e.g. the zeolite ore provided in step 101) using a grinding unit. The grinding unit is configured for performing the grinding and screening of zeolite materials. The grinding unit may have parameters for controlling its function. The parameters may for example comprise the reduction ratio of the grinding unit, the number of times the screening is to be repeated in the screening step; the exciting force causing the vibration of the screening unit; inclined and/or horizontal screening.

[0137] In step 201, a zeolite grain size that corresponds to the maximum surface specific area may be determined. The grain size of the microporous zeolite mineral is determined such that the resulting specific surface area of the mineral is smaller than the maximum specific surface area.

[0138] Naturally, the specific surface area of the microporous zeolite mineral varies with its structure. For example, the finer the mineral is, the larger the specific surface area is (i.e. the smaller the grain size is, the larger the specific surface area is).

[0139] For example, the specific surface area of the microporous zeolite mineral may not exceed a minimum specific surface area. The minimum specific surface area may be the smallest possible specific surface area. In this case, the determined grain size may be the lower limit of a range of sizes, wherein the upper limit of the range may be determined using the minimum specific surface area. The microporous zeolite mineral may for example have a grain size between 0.5 mm and 1.2 mm or between 0.9 mm and 1.2 mm, for a maximum surface specific surface area of 21m.sup.2/g (e.g. the selected specific surface area may be 20 m.sup.2/g).

[0140] In step 203, the zeolite ore may be reduced into smaller zeolite fractions. FIG. 3 shows an example method for reducing the zeolite ore into smaller fractions. The zeolite fractions may for example have a maximum size of 5/8 inch. In order to obtain that maximum size for the fractions, the reducing of the zeolite ore may comprise in addition to crushing the zeolite ore, a sieving or screening step, wherein in the screening step the crushed zeolite ores are screened with series of sieves. For example, the series of sieves may comprise sieves having sieve sizes ranging from about a minus 14 mesh (1.41 mm) to about a plus 40 mesh (0.42 mm).

[0141] In step 205, parameters of the grinding unit may be set in accordance with the determined grain size of step 201. For example, the reduction ratio of the grinding unit may be set such that the grinding unit may provide or output from the zeolite fractions grains having as a maximum size the determined grain size.

[0142] In one example, before performing the grinding step 207, the zeolite fractions resulting from step 203 may be dried in a dryer. This may have the advantage of reducing the amount of dust in the resulting microporous zeolite mineral.

[0143] In step 207, the zeolite fractions may be grind in the grinding unit. The term grinding encompasses processes like cutting, chopping, crushing, milling, pulverizing, and the like.

[0144] After grinding the zeolite fractions, the resulting zeolite material may be screened in step 208, resulting in groups of zeolite grains, wherein each group has a respective minimum grain size. The screening may for example be performed using series of sieves having sieve sizes ranging from about a minus 14 mesh (1.41 mm) to about a plus 40 mesh (0.42 mm). The screening may be a vibratory-type screening.

[0145] In one example, up to six or more different fractions can be separated in one screening process. This may for example be done using multiple sieve decks positioned on top of each other in a classification range such as a range of 0.1 mm to 1.5 mm.

[0146] The maximum grain size of each group of the groups may be compared with the determined grain size of step 201. In case (inquiry 209) the minimum grain size of a group of the groups is higher than the determined grain size, step 208 or steps 207-208 may be repeated. Otherwise, the group may be selected and stored in step 211 as part of the selected microporous zeolite mineral.

[0147] For example, the method may end if the selected microporous zeolite mineral reaches a predefined amount or if the input ore is completed.

[0148] FIG. 5 illustrates the process of selecting a microporous zeolite mineral from a zeolite ore (e.g. zeolite ore of step 101) in accordance with another example of the present disclosure. FIG. 3 shows a crushing unit 301 and a grinding unit 302, wherein the zeolite ore is first processed at the crushing unit 301 and the resulting material is input to the grinding unit 302 for further processing.

[0149] Before processing the zeolite ore in the crushing unit 301, the zeolite ore may for example be obtained as follows. A zeolite deposit is stripped of overburden and stockpiled for use in subsequent mine reclamation. The resulting exposed ore body is drilled to depths between 12 and 14 feet. The drill holes are loaded with an explosive charge that degenerates upon use, leaving no residue in the zeolite ore. From the mine pit, the zeolite ore is hauled by dump truck to the crude ore stockpile at a processing mill.

[0150] The zeolite ore is fed in step 31 through a grizzly 303 with 1616 opening, the output ore of the grizzly 303 travels in step 32 via a first conveyer into a jaw crusher 305 where the output ore of the grizzly 303 is reduced to a 4 inch size resulting in 4 inch ore. The 4 inch ore travels in step 33 via a second conveyor to a double deck Nordberg screen 307 with a inch screen on the top deck. The resulting output of the double deck Nordberg screen 307 is a minus inch material and plus inch material.

[0151] The minus inch material travels in step 34 to a third conveyor toward the grinding unit 302 via a dryer 311. The plus inch material travels back in step 35 via a fourth conveyor to a cone crusher 309 which reduces the plus inch material to at least inch material. The inch material then returns in step 37 to the Nordberg screen 307 via the second conveyor.

[0152] From the third conveyor, the zeolite material output of the Nordberg screen 307 travels in step 34 to a propane fueled rotary kiln dryer 311 where it is heated at 250 C., reducing moisture to 5%, and fed in step 38 to the grinding unit 302.

[0153] The zeolite material is conveyed in step 38 from the dryer 311 via a fifth conveyor to an impact crusher 313 and five-decked Midwestern screens 315. From the screens 315 the zeolite is sized and conveyed in step 39 to a sixth conveyor for packaging e.g. in super sacks 320 ready to ship or the zeolite is returned in step 40 via a seventh conveyor to the impact crusher 313 and which is returned to the Midwestern Screens 315. At the Midwestern screens 315, the products are sized according to customer specifications and either sent to finished product handling. In the finished product handling process: a. the material is either sent to bulk storage silos for direct truck loading or b. The material is sent to packaging silos where it is packaged in customer specified bags and palletized, wrapped, and stored in warehouse for truck pick up.

[0154] The following table gives example properties of the selected microporous zeolite mineral of the present method.

TABLE-US-00001 Parameter Values Granulometry 14 40 mesh (0.42-1.39 mm) Particle size distribution 14 mesh (1.39 mm) 0.9% 20 mesh (0.84 mm) 39.0% 30 mesh (0.59 mm) 27.0% 40 mesh (0.42 mm) 21.0% 100 mesh (0.15 mm) 10.0% <100 mesh 0.6% color/Brighthness White/85 Hardness 3 Porosity 15-20% Arsenic total <4 mg/kg sec Level of humidity 6%

[0155] The values of the parameters, particle size or grain size, color, hardness, arsenic total and level of humidity, listed in the table are central values. However, each parameter of these parameters may have a value in the range defined by the central value, 10%, 5% or 3% of the central value. These values may for example enable to obtain a specific surface area of 20 m.sup.2/g.

[0156] FIG. 6A shows an example of an artificial turf (or artificial turf structure) 400A. The artificial turf 400A comprises an artificial turf carpet 402. The artificial turf carpet comprises a backing 404 and also artificial grass fibers 406. The artificial grass fibers 406 are tufted into the backing 404 and are secured 408 to the backing 404. The artificial turf fibers 406 form a pile 403. The artificial turf carpet 402 is resting on a ground 410 or surface. Between and distributed between the artificial grass fibers 406 and within the pile 403 is an artificial turf infill 412. The infill artificial turf infill 412 is shown as having a cylindrical shape; however it may have other shapes. For example, the shape of the microporous zeolite mineral may be a spherical shape. In this example the artificial turf infill 412 is made from at least the selected microporous zeolite mineral 414. In on example, the artificial infill material may consist of the selected microporous zeolite mineral. In another example, the artificial infill material may comprise the selected microporous zeolite mineral in addition to other infill materials. In another example, the artificial infill material may comprise the mixture of the zeolite mineral with at least one of the copper and the silver.

[0157] FIG. 6B shows a further example of an artificial turf (or artificial turf structure) 400B. The artificial turf 400B is similar to the artificial turf 400A shown in FIG. 6A except there is additionally a sand layer 420 between the artificial turf infill 412 and the backing 404. The use of the sand layer 420 may be advantageous because it may help to hold the artificial turf carpet 402 in place. It may also have the technical benefit that the sand layer 430 works in conjunction with the artificial turf infill 412 to regulate the amount of water on the surface of the artificial turf 400B. For example if it rains or if water is sprayed onto the surface of the artificial turf 400B the composite infill components 414 may rapidly absorb and saturate with water. The sand layer 420 may then aid in draining away excess water and preventing it from standing on the surface of the artificial turf 400B.

[0158] FIG. 6C shows a further example of an artificial turf (or artificial turf structure) 400C. The artificial turf 400C is similar to the artificial turf 400B shown in FIG. 6B with the addition of several additional layers. Directly underneath the backing 404 is an elastic layer 432. The elastic layer 432 may for example be a mat or other material such as sand and elastomeric granulate or a mixture thereof that readily absorbs shock. The elastic layer 432 is optional. The backing 404 and/or the elastic layer 432 may have holes or may be porous so that water that is standing on the artificial turf 400C can be drained away. The elastic layer 432 is directly sitting on a drainage system 430. The drainage system 430 may comprise granulate material, drainage tiles, drainage pipes or other system for rapidly draining water off the surface of the artificial turf 400C. The artificial turf depicted in FIG. 6C may have superior qualities when water is used to cool or improve sliding properties. Water that initially goes on the surface may readily be absorbed by the composite infill components 414 that make up the artificial turf infill 412. When they have filled with water excess water may then go into and possibly be stored in the sand layer 420. When the sand layer 420 is saturated it may drain through the backing 404 and/or the elastic layer 432 into the drainage system 430.

[0159] FIG. 7 shows a further example of the artificial turf e.g. 400A. In this example an automatic sprinkler system 500 has been integrated into the artificial turf 400A. The sprinkler 500 is depicted as spraying water 502 on an upper surface of the artificial turf 400A. The use of the sprinkler may be beneficial in combination with the artificial turf as it may provide an integrated watering system for an optimal watering of the artificial turf.

LIST OF REFERENCE NUMERALS

[0160] 10-23 method steps

[0161] 31-40 method steps

[0162] 101-103 method steps

[0163] 201-211 method steps

[0164] 301 crushing unit

[0165] 302 grinding unit

[0166] 303 grizzly

[0167] 305 jaw crusher

[0168] 307 Nordberg screen

[0169] 309 cone crusher

[0170] 311 dryer

[0171] 313 impact crusher

[0172] 315 Midwestern screens

[0173] 320 sack

[0174] 400A artificial turf

[0175] 402 artificial turf carpet

[0176] 403 pile

[0177] 404 backing

[0178] 406 artificial grass fibers

[0179] 408 secured to backing

[0180] 410 ground

[0181] 412 artificial turf infill

[0182] 414 composite infill component

[0183] 400B artificial turf

[0184] 420 sand layer

[0185] 400C artificial turf infill

[0186] 432 elastic layer

[0187] 430 drainage system

[0188] 500 sprinkler system

[0189] 502 spraying water.