CN117916424A

CN117916424A - Artificial turf infill particles, method for producing such infill particles and use of such infill particles

Info

Publication number: CN117916424A
Application number: CN202280048551.8A
Authority: CN
Inventors: E·伊耶; T·马戴尔; A·拉夫纳斯; M·拉夫纳斯
Original assignee: Goe Ip AS
Current assignee: Goe Ip AS
Priority date: 2021-05-07
Filing date: 2022-05-09
Publication date: 2024-04-19
Also published as: GB202111672D0

Abstract

The present invention relates generally to the field of infill particles for artificial lawns. More specifically, the present invention relates to a infill granule for an artificial lawn, wherein the granule comprises a substrate impregnated with a salt, and the granule is free of thermoplastic material, wherein the substrate comprises cellulosic and/or hemicellulose material, wherein the granule has a volume up to about 512mm ³, wherein the granule has a salt content of at least 5 wt%, and wherein the salt is dispersed throughout the granule. The invention also relates to a method of manufacturing the filler particles of the invention and to an artificial turf system comprising these particles.

Description

Artificial turf infill particles, method for producing such infill particles and use of such infill particles

Technical Field

The present invention relates generally to infill particles for use in artificial lawns. More particularly, the invention relates to a infill granule for an artificial lawn, wherein the granule is made of an organic material. The invention also relates to a method of manufacturing the infill particles of the invention and to an artificial turf system comprising these particles.

Background

Artificial turf has become an important alternative to natural turf in a variety of environments. Football uses artificial turf in large numbers both indoors and outdoors. While artificial turf systems may vary in design and manufacture, they typically share a common component. The artificial turf fibers (or turf piles or artificial grass) themselves are typically made of Polyethylene (PE), the primary backing material being polypropylene (PP), the backing material of polypropylene providing structure and spacing for the braiding of the artificial turf fibers. A secondary backing of Polyurethane (PU) may be applied to adhere the fleece to the backing. One or more backings form a "grass carpet".

There are many different types of artificial turf systems, including hybrid, first generation (1G), second generation (2G) and third generation (3G) turf systems. The mixed grass is a grass formed by combining natural grass with synthetic reinforcing fibers. The first generation of artificial turf systems included short artificial turf fibers. First generation artificial turf systems have been substantially replaced by second and third generation artificial turf systems. Second generation artificial turf systems have longer fibers (e.g. 13 to 24mm in height) and sand infill.

Third generation systems typically comprise longer fibres (e.g. 30 to 60mm in height) and contain two types of fillers, namely "stable fillers" (typically sand) and "performance fillers". Typically, the stabilizing infill is placed in the lower layer between the artificial turf fibers, while the performance infill is placed on top of the stabilizing infill as the upper layer between the artificial turf fibers. The function of the stabilizing infill is to keep the fibres of the artificial turf upright during use, while the function of the performance infill is to mimic the feel of natural grass, for example to provide the correct level of impact resistance, rotation resistance and resilience. Currently, the performance filler used in most artificial turf systems is Styrene Butadiene Rubber (SBR), also known as crumb rubber, which is derived from worn tires. Or a shock pad may be provided under the grass carpet to provide further support.

In a typical artificial grass pitch of 106 x 71m employing SBR as performance filler, 49% of the total weight consists of the stabilizing filler (sand) and 44% of the total weight consists of the performance filler (SBR). The remainder is the plastic grass itself, namely grass carpet and artificial grass fibres.

Thus, the impact of artificial turf systems on the environment is generally mainly determined by the infill material. The property filling market is dominated by SBR, which is used by about 83% of devices. Although sand is also an important component of 3G lawn systems as a stabilizing filler, its recovery process requires much less energy than SBR. It is estimated that 10% of the infill escapes from the artificial turf system annually, i.e. is dispersed into a wider environment.

SBR particle escape has proven to pose serious environmental problems because SBR is difficult to biodegrade and environmentally toxic. It is therefore desirable to provide a less environmentally negative infill that biodegrades after escaping from an artificial lawn and that is non-toxic to the environment.

Cork particles are one of the few known natural filler alternatives. However, cork particles are not suitable for all applications, as they are expensive and degrade faster over time on artificial turf than rubber, so the infill will need to be replenished more frequently over the life of the artificial turf.

Disclosure of Invention

The present invention provides a infill for an artificial lawn, which infill meets the above-mentioned needs. The filler of the present invention has obtained FIFA Quality PRO and FIFA Quality certification (by meeting the performance requirements outlined in EN 15330-1:2013) based on tests performed at approved FIFA laboratories Spots Labs Ltd (see example 3).

In particular, the present invention provides a infill granule for an artificial lawn, wherein the granule contains at least 5% by weight of salt, preferably at least 10% of salt, has a volume of up to 512mm ³, and is made of wood.

The inventors have surprisingly found that wood has technical properties comparable to SBR particles. The filler particles of the present invention thus constitute a product that is capable of functioning as SBR without the associated environmental hazards caused by filler escaping.

These particles are impregnated with a high content of salt. The salt content of the filler particles of the present invention helps the particles to exhibit stability and not decompose too rapidly (resist decomposition and decay). Without wishing to be bound by theory, this effect appears to be caused by the ability of the salt to repel microorganisms and fungi, resulting in filler particles having anti-biodegradability and the salt contributing to the UV radiation resistance of the particles. The salt also makes the particles denser, which gives wood with better filling properties (e.g. for sports fields) than wood not impregnated with high concentrations of salt. Even with high concentrations, salts are not harmful to the environment, neither to humans or other animals that may come into contact with the filling, nor to the broader environment.

The infill proved to be stable on artificial lawns for at least 5 years and was expected to be stable for 10 years. The life of an artificial lawn, i.e. a lawn carpet comprising artificial lawn fibres, is about 10 years, and thus, unlike cork and other known organic fillers, the need for replacement or supplementation of the filler of the present invention is reduced over the life of the artificial lawn.

Throughout this specification, where the terms "comprising", "including" and "comprising" are used, the terms "consisting of … … (consisting of)", "consisting of … … (consist of)" and "consisting of … … (constistof)" are also alternatively considered.

"Infill" refers to any solid particle suitable for use on an artificial lawn. The particles suitable for use on the artificial turf may be particles that mimic the characteristics of natural grass or natural grass land as part of the turf system. The simulated characteristics may be ball rebound, ball rolling, shock absorption, vertical deformation, anti-rotation and/or water permeability of the foot.

Thus, in some embodiments, the infill of the invention is an infill for an artificial lawn (e.g. an artificial football field lawn). In a preferred embodiment, the infill of the present invention is used (or adapted, or adapted for use) in an artificial lawn (e.g. an artificial football pitch lawn) having artificial lawn fibres (preferably monofilament fibres, fibrillated fibres, monofilament fibres with stems, or a combination thereof, more preferably monofilament fibres) with a height of about 25 to 70mm (preferably a height of about 30 to 50mm, more preferably a height of about 40 mm). More preferably, the infill of the present invention is used in (or is suitable for, or is suitable for use in) an artificial lawn (or artificial football pitch lawn) having artificial lawn fibres, which are monofilament lawn fibres and have a height of about 40mm. In a preferred embodiment, the infill of the invention is for (or is adapted to, or is adapted to be used in) third generation (3G) artificial turf. In other words, in a preferred embodiment, the infill of the invention is a third generation (3G) artificial turf infill.

In a preferred embodiment, the infill of the invention is a performance infill, preferably a performance infill for (or adapted to, or adapted to be used in) artificial lawns, more preferably a performance infill for (or adapted to, or adapted to be used in) third generation artificial lawns.

The filler particles (or fillers) of the present invention may be simply referred to as "particles".

The filler particles of the present invention comprise a substrate (also referred to as a base material) impregnated with a salt. In the present invention, the substrate is preferably wood. However, more broadly, it is also contemplated herein that the substrate comprises (or is formed of, or consists essentially of) other cellulosic and/or hemicellulose materials. Thus, where wood is discussed herein, it should be understood that other cellulosic and/or hemicellulose materials (including wood cellulosic materials) are contemplated. Examples of such other non-wood substrates include nut shells, olive pits, cork, coconut, walnut shells, and/or corncobs.

The invention therefore also provides a infill granule for an artificial lawn, wherein the granule contains at least 5% by weight of salt, preferably at least 10% of salt, has a volume of up to 512mm ³, and is made of cellulosic and/or hemicellulose material.

The wood of the filler particles may be whole wood or log. Preferably, the wood is not recycled wood or engineered wood. For example, it is preferred that the wood is not formed from compressed or mixed chips.

Preferably, the filler particles do not contain non-biodegradable materials.

Preferably, the filler particles (or substrate) do not contain thermoplastic material. Composite filler particles of the art may comprise thermoplastic materials with the purpose of bonding the substituents of the particles together. However, the use of thermoplastic materials in the filler particles is disadvantageous because of their potential environmental damage (the thermoplastic materials used in the filler particles may be synthetic and non-biodegradable). In contrast, the process for producing filler particles of the present invention enables salt leaching and then fiber re-combination without the need to disrupt the natural structure of cellulose or hemicellulose. This means that no thermoplastic material is required in the particles of the invention, which is advantageous.

Most preferably, the substrate of the filler particles consists of (or consists essentially of) wood (or cellulosic and/or hemicellulose) material.

The filler particles of the present invention are engineered, manufactured or man-made, preferably manufactured.

The salt is an inorganic salt, typically comprising, consisting of, or consisting essentially of a chloride salt. In a preferred embodiment, the salt is sodium chloride, magnesium chloride, calcium chloride, potassium chloride, sodium sulfate, magnesium sulfate, calcium sulfate, potassium sulfate, or mixtures thereof. In a more preferred embodiment, the salt is sodium chloride, magnesium chloride, calcium chloride, potassium chloride or mixtures thereof. In a more preferred embodiment, the salt consists of sodium chloride, or essentially consists of chloride salts, i.e. the inorganic salt component is at least 95% NaCl, preferably at least 98% NaCl.

In some embodiments, the salt content (or salt concentration) of the filler particles is at least (or up to) about 5、6、7、8、9、10、11、12、13、14、15、16、17、18、19、20、21、22、23、24、25、26、27、28、29、30、31、32、33、34、35、36、37、38、39、40、41、42、43、44、45、46、47、48、49 or 50 wt%. Preferably, the salt content (or salt concentration) of the filler particles is at least about 7 wt%, or at least about 10 wt%, or at least about 15 wt%, or at least about 20 wt%, or at least about 30 wt%, or at least about 40 wt%. Preferably, the salt content of the filler particles is between about 10 wt% and 55 wt%, such as between 10 wt% and 40 wt%, between 20 wt% and 50 wt%, or between 30 wt% and 50 wt%, and in some preferred embodiments between about 20 wt% and 35 wt%. For the avoidance of doubt, the term "% by weight" is the percentage (%) of salt in the total weight of the filler particles. Instead of the term "% by weight", the terms "% by weight", "mass"% by mass ","% mass "can be used as well.

The weight% of salt is calculated on dry particles, e.g. particles that are left for at least one week under dry ambient conditions. The dry ambient conditions may be ambient conditions within the building at normal room temperature (e.g., 20 degrees celsius) and normal humidity (e.g., 30% to 50% humidity, such as 40% humidity).

In some embodiments, the salt content (or salt concentration) of the filler particles is at least (or up to) about 5、6、7、8、9、10、11、12、13、14、15、16、17、18、19、20、21、22、23、24、25、26、27、28、29、30、31、32、33、34、35、36、37、38、39、40、41、42、43、44、45、46、47、48、49 or 50% by volume. Preferably, the salt content (or salt concentration) of the filler particles is at least about 5% by volume, or at least about 10% by volume. Preferably, the salt content is between 5% and 15% by volume. For the avoidance of doubt, the term "volume%" refers to the percentage (%) of salt in the total volume of the filler particles. Instead of the term "% by volume", the term "% volume" may be used as well.

The% by volume of salt is calculated on a dry particle basis, e.g. particles that are left for at least one week under dry ambient conditions.

The size of the filler particles may conveniently be defined by the volume of the particles. The volume of the filler particles may be up to about 512、500、400、343、300、216、200、175、125、120、115、110、105、100、95、90、85、80、75、70、65、60、55、50、45、40、35、30、2520、15、 or 10mm ³. The volume of the filler particles may be at least about 0.001, 0.008, 0.01, 0.1, 1,2,3, 4, or 5mm ³. Preferably, the volume of the filler particles is between about 0.008mm ³ to about 64mm ³, or between about 0.008mm ³ to about 125mm ³. More preferably, the volume of the filler particles is between about 0.1mm ³ to about 125mm ³. Most preferably, the filler particles have a volume of between about 0.5mm ³ and about 64mm ³, for example between about 1mm ³ and about 10mm ³ or 20mm ³, in particular about 8mm ³. The volume is understood to be the size of the particle measured or calculated from its dimensions, the volume of the particle not being reduced simply because it may contain pores (i.e. voids). Therefore, it is preferred that the particles of cubes each dimension of 2mm have a volume of 8mm ³.

Preferably, the filler particles have a volume of between about 0.001mm ³ and about 512mm ³, more preferably between about 0.008mm ³ and about 125mm ³, more preferably between about 1mm ³ and about 64mm ³, more preferably between about 1mm ³ and about 27mm ³.

Most preferably, the filler particles are cubes having dimensions of 2x 2mm and a volume of about 8mm ³. As demonstrated herein, particles of size 2x 2mm are particularly suitable for use as infill for artificial lawns. It is demonstrated herein that such particles exhibit long-term (at least 5 years, possibly 10 years or more) resistance to degradation on artificial turf, but advantageously they degrade rapidly when in the soil. It has also been demonstrated herein that such particles are capable of freezing resistance at temperatures as low as-18 ℃. The dimensions 2x 2mm are also in themselves particularly suitable for artificial turf, being particularly complementary to the dimensions and spacing of the grass fibers commonly found on artificial turf carpets. Particles of 2X 2mm size can also be produced efficiently. Particles of 1 x 1mm cubes are also highly preferred and exhibit excellent packing properties. Cubes having a size of 0.5 to 4×0.5 to 4mm are generally preferred, and rectangular solids of the same size are also preferred.

As demonstrated herein, rounding of the corners of the particles reduces rolling and sliding of the boot on the lawn; thus, salted particles with rounded corners are particularly advantageous as infill for artificial turf. As demonstrated herein, such rounding can be achieved simply by abrasion of the particles during use on the artificial lawn; therefore, the rounding does not need to be completed in the particle manufacturing process, thereby reducing the production cost. However, if desired, the corners of the cube/cuboid may be rounded during the particle manufacturing process, as described elsewhere herein.

The infill particles may be of any shape, preferably any shape suitable for use on artificial turf, more preferably any shape suitable for use on third generation artificial turf. The filler particles may take the shape of any polyhedron. In a preferred embodiment, the filler particles have the shape (or approximate shape) of a cube, cuboid, sphere, ellipsoid, spheroid, ovoid or pyramid, such as a tetrahedron or square pyramid. In a preferred embodiment, the filler particles have a cuboid or cubic shape, more preferably a cube (or approximate shape). Thus, the particles are preferably (approximately) equal in their three dimensions. Preferably, none of the dimensions is greater than 1.5 times the length of any other dimension.

In other embodiments, rectangular parallelepiped particles may be preferred, for example elongated or flat rectangular cubes, for example particles of size 1 x 2mm may be preferred. Other preferred shapes include 1X 4mm, 1X 2mm, 2X 4mm and 2X 4mm. Such particles may make the artificial turf less slippery (e.g. by providing a greater resistance to rotation) than cube filler particles.

Preferably, the cuboid particles are flat in shape rather than elongated, in other words, one dimension is smaller than the other two dimensions, which are identical or approximately identical (rather than one dimension being larger than the other two dimensions, as is the case for elongated cuboid or particles).

In other preferred embodiments, the particles are spheres or spheroids. The preferred diameter is 0.5mm to 4mm, more preferably 1mm to 2mm.

The particles are three-dimensional and it is understood that for a three-dimensional object, the aspect ratio is the ratio of the longest dimension to the shortest dimension. A cuboid is envisaged in which two dimensions are identical and one dimension is longer or shorter than the other two dimensions, or all three dimensions may be different. Thus, the rectangular parallelepiped particle can define an aspect ratio of at least (or up to) 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. Preferably the aspect ratio is between 1:1 and 10:1, more preferably between 2:1 and 5:1.

In some embodiments, the filler particles have a thickness and width dimension in the range of about (0.5 mm to 5 mm) × (0.5 mm to 5 mm). In some embodiments, the filler particles have a cross-sectional and/or length dimension of about 1mm to about 5 mm.

In some embodiments, the filler particles are between 1mm and 5mm in length, and/or the aspect ratio is between 3:1 and 7:1.

In some preferred embodiments, the filler particles of the present invention have a smooth or polished surface. A "smooth or polished" surface according to the invention is a surface that has been treated to reduce roughness and/or soften the sharpness or angularity of edges and/or corners.

In some embodiments, the vertices (or corners) of the shape of the processed filler particles are rounded. The filler particles of the present invention having rounded vertices (or corners) may be advantageous because rounding improves the anti-rotation properties of the lawn on which the filler is distributed. Anti-rotation refers to the ability of the lawn to resist rotational movement of the sole (or foot or boot) when pressed against the lawn. Preferably, the filler particles are in the shape of cubes or cuboids with rounded corners.

In some embodiments, some of the outer pores of the filler particles of the present invention are sealed because they do not provide open channels from outside the particles into the particles. At least 10%, 20%, 30%, 50% or 70% of the pores open on the surface of the particles may preferably be sealed. The pores of the filler particles of the present invention may be sealed by polishing the particles.

The water absorption of the filler particles of the present invention can be reduced compared to log particles of the same size. The water absorption of the filler particles of the present invention may be reduced by having a smooth or polished surface. Alternatively or additionally, the water absorption of the filler particles of the present invention may be reduced by having been impregnated with oil or preservative.

However, it is preferred that the particles are able to absorb some of the moisture so that they behave in a sponge-like manner and mimic the conditions of a conventional lawnmower field in different climates, i.e. harder in dry weather and softer in rain.

The filler particles of the present invention may (or may not) be impregnated with oil or a preservative. The oil or preservative acts as a protective coating (e.g., a water-resistant coating) for the filler particles and acts to improve retention of salts within the particles.

Thus, in a preferred embodiment, the oil is a natural oil (i.e., plant derived) and the preservative is a natural preservative. In a preferred embodiment, the oil is linseed oil (e.g., cold pressed linseed oil). The substitute oil comprises tung oil, olive oil, rapeseed oil or sunflower oil.

In a preferred embodiment, the filler particles do not include a coating. In a preferred embodiment, the filler particles do not contain (or are not coated with) glycerol, xylitol or sorbitol, more preferably they do not contain any polyols. In some preferred embodiments, the filler particles do not contain potassium acetate, sodium formate, sodium acetate, urea, sodium chloride, and/or calcium chloride.

However, in some embodiments, a glycerol (glycerin) coating may be applied in addition to the salt, typically in a separate application step.

The salt leaching process significantly increases the density/weight of the wood, which provides superior properties compared to non-salt leached wood, in particular it enables the particles to meet the density requirements set by FIFA for the filler. Thus, for example, by adding salt, the density of the dry particles is increased by 20 to 60%, preferably at least 30%. Preferably, the dry particles have a density of from 0.3g/ml to 0.7g/ml, more preferably from 0.4g/ml to 0.7g/ml, and in some embodiments, from 0.65g/ml to 0.70g/ml.

In some embodiments, the pellets have a moisture content of about 16-20% (which may still be considered dry pellets) when they are packaged for sale or application in a lawn system or laid down on a court. The filler particles of the present invention generally have a higher (or about the same) density than pure water, such that the filler particles tend to sink in the pure water; it will be appreciated that due to the buoyancy of the wood, the (dry) particles may initially float, but when they are placed in water (e.g. after 30 minutes) the water is absorbed and then the particles become denser and sink than the water. Although wood is naturally buoyant in water, the salt content makes the wet particles larger than water.

In general, the density of the particles depends on the saturation and salinity, so it depends not only on the amount of salt added to the substrate particles, but also on the surrounding or environmental conditions, which will affect the presence (absorption) of moisture in the particles. Typically, the density varies from 0.5g/ml to over 1.0g/ml (e.g., up to 1.1g/ml, 1.2g/ml, or 1.4 g/ml).

The wood of the particles may be natural wood or log, for example, as opposed to engineered wood products formed from reconstituted strands or plies that may have a non-wood binder, such as resin or glue.

The wood of the particles may be softwood or hardwood, preferably hardwood.

Suitable cork includes southern cedar, cedar (Cedrus), apios (Phyllocladus aspleniifolius), cypress (e.g., CHAMAECYPARIS, CUPRESSUS or Taxodium), douglas fir (Pseudotsuga menziesii), european yew (Taxus baccata), fir (abies), hemlock (Tsuga), lacrimago (Huon pine), migratus (Lagarostrobos franklinii), kauri (Agathis australis), kunskava shell (Agathis robusta), japanese torreya (Torreya nucifera), larch (Larix), pine (pinus), red cedar (e.g., juniperus virginiana or Thuja plicata), coastal redwood (Sequoia sempervirens), juniper (Dacrydium cupressinum), spruce (picea), cedar (Cryptomeria japonica), bai Xuesong (e.g., thuja occidentalis or CHAMAECYPARIS THYOIDES), or yellow cypress (Cupressus nootkatensis).

Suitable hardwoods include birch (Betula), alder (Alnus), ash (Fraxinus), aspen (Populus), australian red cedar (Toona ciliata), ash She Qi (Acer negundo), boxwood (Buxus sempervirens), brazil walnut (Ocotea porosa), brazil wood (CAESALPINIA ECHINATA), horse chestnut (Aesculus), catalpa (Catalpa), cassegrain wood (Chloroxylon swietenia), cherry wood (Prunus), chestnut (Castanea), horned wood (Ceratopetalum apetalum), cork (LEITNERIA FLORIDA), poplar (Populus), dogwood (Cornus), ulmus (Diospyros), elm (Ulmus), eucalyptus (Eucalyptus), malus (Malus sylvestris), pear (Pyrus com ni), ironwood, yellow sandalwood (Dalbergia cearensis), lace wood, peach wood (e.g., SWIETENIA, KHAYA, TOONA, ENTANDROPHRAGMA, CHUKRASIA, CEDRELA, GUAREA, CARAPA or Melia), maple (Acer), marble wood (Marmaroxylon racemosum), oak (Quercus), walnut (Juglans) or Salix (Salix).

In some preferred embodiments, the cork is spruce (Picea), more preferably, sirtuin (PICEA SITCHENSIS).

In some particularly preferred embodiments, the hardwood is birch (Betula), such as american birch, preferably ash birch (Betula populifolia), black birch (Betula nigra), paper birch (Betula papyrifera), sweet birch (Betula lenta), virginia circle She Huashu (Betula uber) or yellow birch (Betula alleghaniensis). In some preferred embodiments, the birch is an european birch, preferably silver birch (Betula pendula) or most preferably fluffy birch (Betula pubescens).

As demonstrated in the examples, birch is preferred as a substrate for the filler particles of the present invention due to its particularly advantageous properties. Birch is also particularly advantageous because it has a uniform structure throughout the trunk, and can produce uniform particles. This is important because it provides consistency in physical properties between batches of filler particles. This homogeneity is in sharp contrast to more heterogeneous wood, such as southern yellow pine, which has a harder, more compact core but softer, less compact outer layers. Thus, wood like southern yellow pine is not as ideal for making filler particles as other wood, especially birch, preferably european birch.

Birch used as the preferred substrate for the filler particles of the present invention has enhanced properties over other wood materials, such as southern yellow pine, for example, in terms of energy recovery (which provides greater "rebound") than other wood materials.

Preferably, the size of the plurality of filler particles of the present invention is uniform. For example, at least 70%, 80% or 90% of the particles have a volume within 20%, preferably within 10%, for example 5% (plus or minus), of the average volume.

The infill particles of the invention are resistant to biodegradation when on an artificial lawn. Biodegradation is the breakdown of organic matter by microorganisms such as bacteria or fungi. Virtually all biological compounds and materials undergo biodegradation processes. However, it is the speed of these processes that is important, such as the day, week, year or century. Since organic matter is particularly biodegradable, the level of the anti-biodegradability of the organic filler is very important for determining the life of the organic filler when on an artificial lawn.

The infill particles of the invention are herein demonstrated to be stable on artificial turf for at least 5 years and are expected to last for at least 10 years (in contrast, when the infill particles are placed in soil, they are completely biodegradable within 3 months). This is particularly advantageous as it means that the infill particles of the invention are commercially useful as infills for artificial lawns.

The particles are preferably stable, e.g. capable of stabilizing their functional properties and structure for at least 5 years when placed on an artificial lawn.

In order for an artificial turf system to function in cold weather, it is important that the infill (including the performance infill) does not freeze, otherwise the surface will not mimic the conditions of normal grass. Frozen fillings will not have as advantageous properties as non-frozen fillings. It is therefore desirable that any filler particles be resistant to low temperature freezing.

The filler particles of the present invention are freeze-resistant. Without wishing to be bound by theory, this may be due to the high salt content (or salt concentration) of the filler particles, and also due to the wood of the filler particles. The filler particles of the present invention are preferably freeze-resistant, i.e. not frozen, down to-10 ℃, 15 ℃ or even-18 ℃.

In certain events that are held on an artificial lawn, pyrotechnical and/or firework may be used (e.g. during rest of a sporting event. Fire protection of the artificial lawn is important in order to achieve this, fire protection of the infill is important in this case, since the infill occupies a large part of the artificial lawn.

Thus, in embodiments, the filler particles of the present invention are refractory or nonflammable. In embodiments, the filler particles of the present invention are substantially or completely refractory. In embodiments, the filler particles of the present invention are more refractory than the corresponding salt-free or unmodified forms of the particles.

The filler particles of the present invention are preferably less susceptible to degradation by UV radiation than untreated wood of the same size.

The filler particles according to the present invention may comprise filler particles of two or more shapes. In a preferred embodiment, the two or more shapes are selected from the group consisting of cubes, cuboids, spheres, ellipsoids, spheroids, ovoids, or pyramids.

The filler particles used according to the present invention may comprise filler particles of two or more sizes. In some embodiments, the plurality of filler particles of the present invention may include a first type of filler particles and a second type of filler particles, wherein the first type of filler particles has a volume at least 2 or 3 times that of the second type of filler particles. For example, two cubes of different sizes, such as a 1mm by 1mm cube, and a 2mm by 2mm cube, may be used.

The particles of the present invention may be used with a second particle made from a different substrate. In a preferred embodiment, the second particles are sand, such as silica sand.

The artificial turf system according to the invention may comprise a lower layer of particles and an upper layer of particles, wherein the upper layer comprises the particles according to the invention and the lower layer comprises a second type of particles suitable for use as an artificial turf filling. In a preferred embodiment, the second particle type is sand. In a preferred embodiment, the sand is silica sand. In such an arrangement, the filler particles of the present invention may be referred to as performance fillers, and the second particle type (e.g., sand) is a stable filler.

In some embodiments, the filler particles have a fill factor of about 1.5, 2, 2.5, or 3, preferably about 2. The fill factor is a measure of the total volume of a group of stacked particles divided by the sum of the total volumes of all particles individually. Thus, the increased volume in the collection of particles (as compared to the total volume of all particles alone) is the void between the packed particles.

Thus, the fill factor reflects the volume of air present between the particles. The air between the particles contributes to the softness and technical properties of the infill (and the lawn surface when the infill is applied). Therefore, it may be advantageous to have a fill factor higher than 1. In particular, the filler particles of the present invention may have a fill factor of 1 to 3, 1.5 to 2.5, or about 2.

The present invention also provides a method of producing the filler particles of the present invention, the method comprising:

Immersing particles made of wood having a volume up to about 512mm ³ in a salt solution; and optionally drying the impregnated particles.

In the present invention, wood is generally a preferred example of cellulose and/or hemicellulose particles. Accordingly, the present invention also provides a method of producing the filler particles of the present invention, the method comprising:

Immersing particles made of cellulosic and/or hemicellulose material in a salt solution in a volume of up to about 512mm ³; and optionally drying the impregnated particles.

In embodiments, the particles made from wood have a volume of up to about 512、500、400、343、300、216、200、175、125、120、115、110、105、100、95、90、85、80、75、70、65、60、55、50、45、40、35、30、25、20、15、 or 10mm ³. The volume of particles made from wood may be at least about 0.001, 0.008, 0.01, 0.1, 1, 2, 3, 4, or 5mm ³. Preferably, the volume of the particles made of wood is between about 0.008mm ³ to about 64, or between about 0.008mm ³ to about 125mm ³. More preferably, the volume of the particles made of wood is between about 0.1mm ³ to about 125mm ³. Most preferably, the volume of the particles made of wood is between about 0.5mm ³ and about 64mm ³, for example between about 1mm ³ and 10mm ³ or 20mm ³, in particular about 8mm ³. The volume is understood to be the size of the particle measured or calculated in terms of its dimensions, the volume of the particle not being reduced simply because it may contain pores (i.e. voids). Therefore, it is preferred that the cubic particles each dimension of 2mm have a volume of 8mm ³. Preferably, the volume of the particles made from wood is between about 0.001mm ³ and about 512mm ³, more preferably between about 0.008mm ³ and about 125mm ³, more preferably between about 1mm ³ and about 64mm ³, more preferably between about 1mm ³ and about 27mm ³.

The preferred features of the particles defined above apply mutatis mutandis to the method.

In embodiments, particles made from wood have corners and edges, wherein the corners and edges are rounded.

The impregnation step is sufficient to provide the particles with a salt content as described herein, i.e. at least 5wt%, preferably at least 10 wt% salt. The impregnation step may be sufficient to allow the salt to penetrate throughout the particle.

The particles are immersed in a brine, wherein the water preferably has a salt concentration of at least about 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, or 360g/L (i.e., grams per liter). Preferably, the salt solution is a saturated salt solution, and the exact concentration at which saturation is achieved will depend on the temperature of the water. Preferably the salt concentration is 300 to 400g/L, more preferably 320 to 380g/L, for example about 360g/L.

The salt solution (brine) is preferably heated to, for example, at least 50 ℃, at least 70 or 75 ℃ or to about the boiling point before and/or during impregnation. The temperature is preferably 70 to 80 ℃, for example around 75 ℃. Conveniently, the water may be heated prior to the addition of salt, and the particles may then be added to the brine/salt solution.

The rate at which a wood sample absorbs liquid (e.g., water or brine) may increase as the viscosity of the liquid decreases and as the surface area and permeability of the wood increases. By increasing the temperature of the liquid and the wood, respectively, it is possible to reduce the viscosity of the liquid (e.g. brine) and to increase the surface area (e.g. swelling by cellulose and hemicellulose) and the permeability (e.g. swelling by pores) of the wood. Thus, by salifying wood particles in brine at high temperatures, the rate at which the particles absorb salt is significantly increased compared to the same protocol at ambient temperature (i.e., when conducted at high temperatures, the salt absorption stage may take as short as, for example, 15 minutes, versus days or weeks when conducted at ambient temperature). Immersion in a heated salt solution is generally preferred, but not always the case.

In the impregnation method of the invention, the liquid not only travels through the wood fibres/pores, but also penetrates through the cellulosic and hemicellulose fraction between the fibres/pores. This is facilitated by the use of a high temperature liquid, as this enables the cellulose and hemicellulose fraction of the wood to expand, as described above. Immersing the wood substrate in high temperature brine results in the formation of wood particles, wherein the salt is dispersed throughout the particles. The dispersion of salt throughout the particles of the invention is advantageous, for example, compared to simply coating the particle surface with salt. For example, dispersing the salt throughout the particles enables the particles of the present invention to retain a higher amount of salt than particles coated with salt alone. Furthermore, the dispersion of the salt throughout the particles means that the advantageous properties of the salt as described herein may be exhibited throughout the particles, for example in terms of resistance to degradation and freezing. Thus, by dispersing the salt throughout the filler particles of the present invention, the advantageous properties associated with salt impregnation are enhanced.

The impregnation method of the present invention is different from coating in that only the surface of the particles is coated and hardly penetrates into the inside of the particles.

Thus, in the filler particles of the present invention, the salt is dispersed (substantially or completely) throughout the particles. In other words, the whole (or the whole, or all) of the particles are impregnated with salt.

In some preferred embodiments, the impregnating step is from about 5 minutes to 60 minutes, preferably from about 5 minutes to 10 minutes, from 10 minutes to 15 minutes, from 15 minutes to 20 minutes, from 20 minutes to 25 minutes, from 25 minutes to 30 minutes, from 30 minutes to 35 minutes, from 35 minutes to 40 minutes, from 40 minutes to 45 minutes, from 45 minutes to 50 minutes, from 50 minutes to 55 minutes, or from 55 minutes to 60 minutes. In some embodiments, the impregnating step is at least 10 minutes, at least 15 minutes, or at least 20 minutes, more preferably at least 10 minutes. In some embodiments, the impregnating step is from about 10 to 40 minutes, preferably from about 15 to 35 or 20 to 35 minutes, more preferably about 30 minutes.

The method of producing the filler particles of the present invention may further comprise, for example, polishing the surface of the filler particles after the drying step.

As used herein, "polishing" refers to a process of forming a smooth surface on the filler particles of the present invention by abrasion and/or mechanical stress/pressure. In addition to a smooth surface, the polishing may round any edges/vertices and corners on the particles. As discussed elsewhere herein, this may have beneficial properties in terms of performance and sealing the aperture to prevent water ingress during use.

Polishing methods, such as methods of polishing wood, are well known in the art. For example, it is known to smooth wood surfaces by sanding. The mechanical sanding may be performed using a sander or a sanding machine with sandpaper attached. To round the corners of cubes and/or to polish particles, a belt sander using grade 200 sandpaper may be conveniently used. One suitable machine is known as a belt sander, such as SANDTEQ-W-200 of HOMAG groups. "polishing" and "buffing" are synonymous herein.

Another method of polishing the filler particles of the present invention is by passing the particles through a plurality of wear cycles (e.g., 20,200 cycles or 40,200 cycles) using a wear simulator, such as a Lisport (i.e., lisport classical) wear simulator.

Thus, the polishing step produces filler particles of the present invention having a smooth or polished surface. This reduces the water absorption of the filler particles. This is advantageous because the water absorption is associated with the degradation of filler particles composed of organic materials.

Without wishing to be bound by theory, it is understood that the reduction in water absorption may be achieved by the polishing process or by plugging the pores of the particles (or more specifically, the pores of the wood constituting the particles). Thus, the polishing step may cause some of the outer pores of the filler particles of the present invention to become sealed.

Methods for obtaining particles made of wood (e.g. for use in a salt leaching process) are known in the art. For example, particles made of wood may be obtained by wood milling. Or particles made of wood may be obtained by cutting wood particles from a wood board or veneer. The planks and veneers may be cut using one or more known bladed tools, such as a saw, for example, a reel saw, a hacksaw, a jig saw, a circular saw, a miter saw, a reciprocating saw, or a trimming saw. Most suitably, band saws (e.g. ScheppachHBS 261) cut the board to size. Alternatively, guillotine cutters (e.g., after cutting using heavy equipment such as a band saw) may be used to precisely cut the particles; the spacing of the blades of the guillotine cutter may be adjusted to achieve a desired size of wood particles cut from the board. Thus, band saws can be used to produce wood having the desired grain size in two dimensions, and then guillotine cutters can be used to produce the grain itself by cutting to the desired size in three dimensions.

In the present invention, wood is generally a preferred example of cellulose and/or hemicellulose particles. Thus, the above method is also applicable to obtaining particles made of other cellulosic and/or hemicellulose materials.

In a further aspect, the present invention provides a method of producing wood filler particles for an artificial lawn, the method comprising cutting wood to form particles having a volume of up to about 512mm ³ (preferably 1 to 8mm ³) per particle, the particles being in the shape of a cuboid, preferably a cube; the cut particles are then ground (polished) to round the corners. The preferred features of the particles described elsewhere herein and the cutting and grinding methods are applicable mutatis mutandis to this aspect of the invention.

In the present invention, wood is generally a preferred example of cellulose and/or hemicellulose particles. The above-described method is thus also applicable to the production of granules for artificial turf made of other cellulosic and/or hemicellulose materials.

In embodiments, the round particles have a volume up to about 512、500、400、343、300、216、200、175、125、120、115、110、105、100、95、90、85、80、75、70、65、60、55、50、45、40、35、30、25、20、15、 or 10mm ³. The volume of the circular particles may be at least about 0.001, 0.008, 0.01, 0.1, 1,2,3,4, or 5mm ³. Preferably, the volume of the circular particles is between about 0.008mm ³ to about 64mm ³, or between about 0.008mm ³ to about 125mm ³. More preferably, the volume of the circular particles is between about 0.1mm ³ to about 125mm ³. Most preferably, the volume of the circular particles is between about 0.5mm ³ and about 64mm ³, for example between about 1mm ³ and 10mm ³ or 20mm ³, in particular about 8mm ³. The volume is understood to be the size of the particle measured or calculated in terms of its dimensions, the volume of the particle not being reduced simply because it may contain pores (i.e. voids). Therefore, it is preferred that the cubic particles each dimension of 2mm have a volume of 8mm ³. Preferably, the volume of the circular particles is between about 0.001mm ³ and about 512mm ³, more preferably between about 0.008mm ³ and about 125mm ³, more preferably between about 1mm ³ and about 64mm ³, more preferably between about 1mm ³ and about 27mm ³.

The round particles described above may be impregnated with salt (e.g., by the impregnation methods described elsewhere herein) to produce filler particles of the present invention.

The terms "synthetic turf" and "artificial turf" are used interchangeably herein.

By "artificial turf infill" or "infill for an artificial turf" is meant an infill suitable for an artificial turf (or for use on an artificial turf), i.e. as part of an artificial turf system. "Artificial turf" refers to artificial, manufactured or manufactured turf suitable for athletic activities. Examples of artificial turf include hybrid, first generation (1G), second generation (2G) and third generation (3G) turf. These terms are well known in the art and are described above.

The filler of the present invention is suitable for all artificial or synthetic surfaces. In a preferred embodiment, the infill of the invention is suitable for use with first, second or third generation artificial turf, preferably third generation artificial turf.

Accordingly, in a further aspect, the present invention provides an artificial turf system comprising:

An artificial turf carpet comprising artificial turf fibers; and

The plurality of filler particles of the present invention.

In a preferred embodiment, the plurality of filler particles are uniformly distributed on the artificial turf

In a preferred embodiment, the artificial turf system further comprises sand.

The artificial turf system may be any artificial turf system suitable for sports. In a preferred embodiment, the artificial turf system is an artificial turf system for (or suitable for) a ball game, preferably a rugby or football.

In a preferred embodiment, the grass carpet includes a backing. The turf carpet may include a primary backing and a secondary backing (in addition to the artificial turf fibers). In some embodiments, the primary backing is polypropylene (PP) and the secondary backing is Polyurethane (PU) or latex.

The artificial turf carpet comprises artificial turf fibers. The terms "fiber" and "fluff" are used interchangeably herein. The artificial turf fibers may be any fibers suitable for use as part of the artificial turf system. The artificial turf fibers may be monofilament fibers, fibrillated fibers, stemmed monofilament fibers, or a combination thereof, with monofilament fibers being preferred. In a preferred embodiment, the artificial turf fiber comprises, or consists of: polypropylene, polyethylene, nylon (polyamide), or combinations thereof. In an embodiment, the artificial turf fibers have a height of about 25 to 70mm. The artificial turf fibers in preferred embodiments have a height of about 25mm to 30mm, 30mm to 35mm, 35mm to 40mm, 40mm to 45mm, 45mm to 50mm, 55mm to 60mm, 60mm to 65mm or 65mm to 70mm. In a preferred embodiment, the artificial turf fibers have a height of about 30 to 50mm, preferably about 40 mm.

In the artificial turf system of the present invention, a plurality of infill particles are distributed between a plurality of artificial turf fibers. In other words, the infill particle(s) are arranged between a plurality of said artificial lawn fibers. In other words, a plurality of filler particles are distributed or arranged between the particles of said artificial turf fibers, i.e. particles are points where the fibers protrude from, emanate from or adhere to the (underlying) artificial turf carpet. The plurality of filler particles may be located at any point between the fibers, such as any point between the fibers, whether horizontal or vertical.

In one aspect, the present invention provides a lawn or grass or soccer field comprising the infill particle or particles of the present invention. In some embodiments, the lawn or grass or soccer field (further) comprises sand.

The present invention provides filler particles produced by any of the methods of the invention disclosed herein, wherein the filler particles have the characteristics of the filler particles of the invention as defined herein.

In a further aspect, the present invention provides the use of the infill granule or the plurality of infill granules of the invention as an infill for an artificial lawn. In an embodiment, the artificial turf is a third generation (3G) artificial turf.

Drawings

The invention will now be further described in the following non-limiting examples with reference to the following figures, in which:

FIG. 1 provides a graphical representation of the data in Table 18.

Fig. 2 shows an image of the filler particles of the present invention, each made of birch, having a size of 2 x 2mm and a salt content of 30.5 wt.%. FIG. 2A shows the new, unused filler particles; it can be noted that these particles have a rough, salt-containing surface. FIG. 2B shows the same type of filler particles after 20,200 cycles of particle operation on a Liport (i.e., liport abrasion) simulator; it can be noted that the particles were significantly smooth, polished and glossy. FIG. 2C shows filler particles of the same composition after 40,200 cycles of particle operation on a Liport (i.e., liport abrasion) simulator; it can be noted that the appearance of the particles is substantially unchanged compared to the particles of fig. 2B.

Fig. 3 shows the results of example 4, an image of the inventive filler particles (each made of birch, size 2 x 2mm, salt content 30.5 wt%) after 5 years of placement on an artificial lawn under severe weather conditions. As shown in fig. 3, the filler particles are still stable.

Detailed Description

Examples

Example 1 method of producing particles by cutting Wood Board

Using standard band saw (Scheppach)HBS 261) two-dimensionally cut a 100×100×5000mm wood board to 2mm.

Then, the cubes of 2x 2mm are precisely cut using a knife with a cutting window of 500 x 30mm with support. The 10 high performance blades were placed side by side with a gap of 2mm and a cutting speed of up to 100 meters per minute.

EXAMPLE 2 impregnation of wooden particles with salt to produce filler particles of the invention

Example 2A methods and results

Step (a)

1. Water is added to a large vessel.

2. Adding salt into water.

3. Culturing is performed with heat (e.g., 75 ℃) until all salts are dissolved.

4. Wood particles (granules) are added to the brine.

5. Soaking for at least 15 minutes.

6. The water was drained and the wet granules were collected.

7. The wet granules were dried on a table.

Table 1-2 mm particles "refer to particles having a size of 2X 2 mm. "1mm particles" refers to particles having a size of 1X 1 mm.

Measurement of

Density of 1mm wet particles: 0.63g/ml

Density of 2mm wet particles: 0.67g/ml

Density of salt: 1.25g/ml

Density of 30% w/v salt solution:

First 1.12g/ml (density of salt solution during mixing (mass/volume of 1 liter vessel))

O1.15 g/ml (Density at the beginning of the salt leaching Process)

First 1.17g/ml (Density of residual Water after removal of the particles after immersion)

Density of 2mm dry salt-free particles: 0.326g/ml

Density of 2mm dry particles after salt leaching: 0.426g/ml

Density of 1mm dry salt-free particles: 0.264g/ml

Density of 1mm dry particles after salt leaching: 0.325g/ml

Whole plate density: 0.62g/ml (weight/volume of 3mm veneer)

Salt content and residual water contrast

Brine:

O volume = 5.8 litres,

Density =1.12 g/ml (liquid volume of 5 litres of water and 1.25 litres of salt is 5.8 litres)

Residual water:

O volume = 3.8 litres

Density ° = 1.17g/ml (representing about 4% evaporated water)

Moisture absorbed in the particles:

1.95 liters, yielding 0.585 liters of salt (736 g)

Add 3 liters of dry particles; dry mass before the salt leaching process = 960 grams, after soaking in brine = 1620 grams; 660 g (also possible compared to 736 g, taking into account some evaporation and salt precipitation).

Conclusion and comment

All measurements indicate good salt saturation

The temperature rise will cause the salt to dissolve more quickly

Smaller particles aggregate more, absorb more moisture, and require longer drying times

EXAMPLE 2B calculation of the salt content in the particles after 2mm dry salt leaching

Calculation of volume percent

To calculate the volume of salt in the dry, salted particles, the following formula can be used:

(x) Density of salt + (1-x) density of dry salt-free particles = density of particles after dry salt leaching

Where 100 x is the volume% of salt in the particles after dry salt leaching (i.e., the percentage of salt to the total volume of the particles).

Thus, the following densities apply:

density of 2mm dry salt-free particles = 0.326g/ml

Density of 2mm dry salt-immersed particles = 0.426g/ml

Density of salt = 1.25g/ml

Substituting the above values into a formula to obtain:

(x)*1.25+(1-x)*0.326＝0.426

Thus (2)

x＝0.104

Thus, the volume% of salt in the 2mm dry post-salt-leaching particles was 10.4 volume%

Calculation of mass% (i.e. by weight)

TABLE 2

Thus, the mass% of salt in the 2mm dry salt-immersed particles (i.e. the percentage of salt to the total mass of the particles) is 0.130/0.426 = 0.305 = 30.5 mass% (i.e. by weight)

EXAMPLE 2C calculation of the salt content in the 1mm Dry salt-immersed particles

Calculation of volume percent

The same formula as provided in example 2B can be used:

Where 100 x is the volume% of salt in the particles after dry salt leaching (i.e. the percentage of salt to the volume of the particles).

Thus, the following densities are applied to the formula:

Density of 1mm dry salt-free particles: 0.264g/ml

Density of 1mm dry salt-immersed particles: 0.325g/ml

Density of salt = 1.25g/ml

Give out

(x)*1.25+(1-x)*0.264＝0.325

Thus (2)

x＝0.0619

Thus, the volume% of salt in the 1mm dry salt-immersed particles was 6.19 volume%

Calculation of mass%

TABLE 3 Table 3

Thus, the mass% of salt in the 1mm dry salt-immersed particles was 0.07738/0.325 = 23.8 mass% (i.e. by weight)

Example 3-Spots Labs Ltd test of the fillers of the invention according to the performance requirements outlined in EN 15330-1:2013

This example provides data from tests performed by Sports Labs Ltd to confirm the applicability of the infill particles of the invention on artificial lawns. The following tests were performed according to BS EN 15530-1:2013 (sports area surface—synthetic grass and needled surface designed mainly for outdoor use).

BS EN 15530-1:2013 is a document published by the British Standards Institute (BSI) in 2013 that provides a series of tests that need to be performed to meet the requirements of artificial turf infill. Each test itself is described in detail in a separate published document, and each of these documents is assigned a specific "EN number" for clear and unambiguous identification. Table 18 provides the EN number for each test performed on the filler particles.

The properties of the filler particles were also tested after abrasion simulation on a Lisport (i.e. Lisport abrasion) abrasion simulator. The Lisport wear simulator consists of two heavy rollers with round 13mm nylon studs. The device traverses the sample (i.e., the artificial turf containing infill) for a prescribed number of cycles. The stud pressed against the sample and simulated wear caused by years of motion use.

The particles tested were all made of birch, 2 x 2mm in size and 30.5% by weight salt content, calculated in example 2.

TABLE 4 Table 4

TABLE 5

TABLE 6

TABLE 7

TABLE 8

TABLE 9

Table 10

TABLE 11

Table 12

TABLE 13

TABLE 14

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TABLE 15

Table 16

TABLE 17

Table 18 shows the results of passing birch of size 2X 2mm, a collection of filler particles of the present invention, through a screen to confirm the size distribution of the particles. The following results confirm that the particles have the claimed dimensions. For a chart of the data in table 18, please refer to fig. 1.

TABLE 19

Conclusion(s)

The submitted products were tested according to the performance requirements outlined in EN 15330-1:2013. According to the test results, the provided product meets all performance requirements of EN 15330-1:2013 for surfaces designed primarily for soccer.

Table 20 shows the technical results of the filler particles of the invention, each made of birch, with dimensions of 2 x 2mm, which have been subjected to 40,200 cycles on a Lisport (i.e. Lisport classical) abrasion simulator. FIG. 2C shows images of particles after 40,200 cycles; it can be seen that the particles were significantly smooth, polished and shiny.

This method not only simulates wear, but is also a suitable method of providing the particles of the invention with rounded corners, which may be preferred in some cases.

Table 21

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EXAMPLE 4 stability of the infill particles of the invention on Artificial turf

A set of infill particles according to the invention, each made of birch with dimensions 2 x 2mm and having a salt content of 30.5% by weight, was placed on an artificial turf outdoors in norway, stawang for 5 years. After 5 years, the group of filler particles was analyzed; the filler particles were found to be still stable (fig. 3). This is particularly impressive in view of the severe weather conditions of the stravang.

EXAMPLE 5 stability of the filler particles of the present invention on soil

A set of the filled particles according to the invention, each made of birch with a size of 2 x 2mm and a salt content of 30.5% by weight, was placed in outdoor soil in the norway st awn lattice. Analyzing the soil after 3 months; the results indicate that the filler particles have completely degraded in the soil.

Claims

1. A filler particle for an artificial lawn,

Wherein the particles comprise a substrate impregnated with a salt and the particles are free of thermoplastic material;

wherein the substrate comprises cellulosic and/or hemicellulose material;

Wherein the particles have a volume up to about 512mm ³;

Wherein the particles have a salt content of at least 5 wt%, and

Wherein the salt is dispersed throughout the particle.

2. The filler particle of claim 1, wherein the substrate consists essentially of cellulosic and/or hemicellulose material.

3. The filler particle of claim 1, wherein the substrate is comprised of cellulosic and/or hemicellulose material.

4. A filler particle according to any one of claims 1 to 3, wherein the particle is a manufactured filler particle.

5. The filler particles of any one of claims 1 to 4, wherein the volume of the particles is between 0.001mm ³ and 512mm ³.

6. The filler particles of any one of claims 1 to 5, wherein the volume of the particles is between 0.008mm ³ and 125mm ³.

7. The filler particles of any one of claims 1 to 6, wherein the volume of the particles is between 1mm ³ and 27mm ³.

8. Filler particles according to any one of claims 1 to 7, wherein the particles are in the shape of cubes, cuboids, spheres, ellipsoids, spheroids, ovoids or pyramids, preferably cubes, more preferably cubes with dimensions 2mm x2 mm.

9. The filler particle of any one of claims 1 to 8, wherein the particle has corners, and wherein the corners are rounded.

10. The filler particles of any one of claims 1 to 9, wherein the particles have a smooth or polished surface.

11. The filler particles of any one of claims 1 to 10, wherein the substrate is wood.

12. The filler particles of claim 11, wherein the wood is natural wood or log.

13. The filler particles of claim 12, wherein the wood is softwood or hardwood.

14. The filler particles of claim 13, wherein the wood is birch.

15. The filler particles according to any one of claims 1 to 14, wherein the particles are impregnated with oil or a preservative.

16. The filler particle of claim 15, wherein the oil is a natural oil and the preservative is a natural preservative.

17. The filler particle of claim 16, wherein the oil is linseed oil.

18. A plurality of filler particles, wherein each filler particle is a filler particle as defined in any one of the preceding claims, and wherein the plurality of particles comprises filler particles of two or more shapes and/or comprises filler particles of two or more sizes.

19. The plurality of filler particles of claim 18, wherein the two or more shapes are selected from the group consisting of cubes, cuboids, spheres, ellipsoids, spheroids, ovoids, or pyramids.

20. The plurality of particles of claim 18 or 19, comprising a first type of filler particles and a second type of filler particles, wherein the first type of filler particles has a volume at least 2 or 3 times that of the second type of filler particles.

21. A method of producing the filler particles of any one of claims 1 to 17, the method comprising:

immersing particles comprising a substrate in a salt solution, the substrate comprising cellulosic and/or hemicellulose material, wherein the particles are free of thermoplastic material and have a volume of up to about 512mm ³; optionally, a third layer is formed on the substrate

The soaked granules were dried.

22. The method of claim 21, further comprising polishing the particles.

23. The method according to claim 21 or 22, wherein the salt solution has been heated to at least 50 ℃, preferably to about 75 ℃.

24. The method of any one of claims 21 to 23, wherein the particles remain in the salt solution for at least 10 minutes.

25. An artificial turf system comprising:

An artificial turf carpet comprising artificial turf fibers; and

A plurality of filler particles according to any one of claims 1 to 20.

26. The artificial turf system of claim 25, further comprising sand.

27. A method according to any one of claims 21 to 24, comprising a step of obtaining the particles prior to the impregnating step, the step comprising cutting cellulosic and/or hemicellulose material to form particles having a volume of up to about 512mm ³ per particle, the particles being cuboid in shape, preferably cubic; the cut particles are then polished to round the corners.

28. Use of the infill particles of any one of claims 1 to 17 or the plurality of infill particles of any one of claims 18 to 20 as an artificial turf infill.