Artificial turf infill containing natural rubber granules

Abstract

A natural rubber based infill for artificial turf, the infill comprising biodegradable granules 19, the biodegradable granules comprising natural rubber that has been physically, rather than chemically, modified by the addition of an amount of a filler material, the biodegradable granules having an average size of 0.2 to 5 mm.

Description

Technical Field

[0001] The present invention relates to a filler for an artificial turf system, comprising unvulcanized natural rubber. The present invention further relates to a method for manufacturing a filler for an artificial turf system, and an artificial turf system comprising said filler.

Background Art

[0002] Artificial turf systems can be used instead of natural turf or as an alternative greening for sports, aesthetic, environmental, and other purposes, and have evolved through several generations to their current form. Generally, such systems attempt to achieve the same characteristics as their natural counterparts, but in certain areas, they may already exceed these, at least with regard to the predictability of behavior.

[0003] A typical turf system comprises an underlay layer having an upper surface and a filler layer of soft and / or hard granules disposed between fibers. The underlay layer can consist of a woven fabric that provides pile fibers to which artificial turf fibers are tufted, oriented in an upward position, and typically fixed to the woven fabric by a coating of latex or polyurethane. Alternatively, the underlay and pile fibers can be produced simultaneously by weaving, such as in a woven velvet carpet. Here, there is considerable freedom in the position of the pile fibers and the underlay structure.

[0004] Often, the turf system will contain filler particles scattered between the upright pile fibers. These provide a combination of functions including the stability of the system and sports performance characteristics. These performance characteristics depend on the intended use, but in most sports will include: rotation and linear grip as defined by relevant sports bodies such as FIFA and World Rugby, shock absorption, vertical ball bounce, and rotational friction. This performance can be further supported by applying a shock pad or e-layer directly under the underlay layer. One such system is described in UK Patent Application No. GB2429171.

[0005] Efforts are ongoing to develop new elastomer granules useful as fillers. By carefully adjusting the properties of the granules that make up this filler material, it is possible to further improve the performance characteristics of artificial turf equipped with these granules. In addition, the need to develop more sustainable technologies also applies to artificial turf technology. With this in mind, it is necessary to develop new filler materials with a minimal environmental footprint. A promising pathway to improve the sustainability of filler materials is to recycle or upgrade waste flows to make them suitable for use as performance and / or support fillers. Such processes, however, can be difficult to control precisely due to the variability of the materials offered for recycling. Furthermore, fully recyclable or biodegradable materials are desirable to prevent the introduction of plastics into the environment that may remain and cause pollution. The pollution caused may be the result of the diffusion of microplastics into the environment, which poses a potential health risk to human and animal health.

[0006] Microplastics are defined by the European Chemicals Agency (ECHA) as materials consisting of solid polymers containing particles to which additives or other substances may be added, where ≥1% w / w particles are (i) all dimensions 1 nm ≤ x ≤ 5 mm, or (ii) for fibers, length 3 nm ≤ x ≤ 15 mm and length-to-diameter ratio > 3. Such micron-scale plastic fragments can remain in the environment after larger scattered or discarded plastic fragments have been mechanically decomposed. Microplastics have been shown to have the potential to cause serious health problems because they tend to travel through the food chain and accumulate in the internal organs of humans or animals.

[0007] It would be desirable to provide an improved filler that mitigates at least some of the problems inherent in existing filler materials. [Overview of the Initiative]

[0008] According to the present invention, a natural rubber-based infill for artificial turf is provided, the infill comprising biodegradable granules, the biodegradable granules comprising natural rubber that has been chemically, rather than physically, modified by the addition of a certain amount of filler material, and the biodegradable granules having an average size of 0.2 to 5 mm.

[0009] Natural unvulcanized rubber is a polymer polymerized in nature. It is sometimes called natural latex and is primarily derived from the rubber tree (Rumex rotundifolia). Polymers found in nature are considered to be inherently biodegradable unless their chemical structure is modified. As used herein, the term “biodegradable” refers to a material that breaks down naturally and, once broken down, re-enters the ecosystem, leaving only naturally occurring materials. This term therefore excludes petrochemical plastics that remain in the environment and cause pollution. This term and other terms mentioned below are interpreted in the context of the EU REACH Regulation (Regulation 1907 / 2006 on the registration, evaluation, authorization and restriction of chemicals).

[0010] In conventional processes, natural rubber is vulcanized or otherwise crosslinked by the addition of appropriate crosslinking additives such as sulfur. The resulting rubber products are generally not considered biodegradable, as they take more than 100 years to decompose under normal environmental conditions. Natural rubber is primarily polyisoprene, and after vulcanization, it is considered to be chemically modified due to the presence of crosslinks between the polymer chains of the polyisoprene molecules. Unvulcanized natural rubber can be decomposed relatively easily into microbial biomass in just a few years under naturally occurring environmental conditions. This process can be accelerated by the presence of additional enzymes and other microorganisms, as well as under specific temperature and light conditions. This makes the filler claimed in this invention particularly suitable for use in situations where biodegradability is important.

[0011] In this context, the term “physically modified rather than chemically modified” should be understood in the context of REACH and is intended to indicate that natural rubber products are neither vulcanized nor chemically crosslinked. Physical modification can be understood to include mixing rubber with other materials, as shown below. It also includes physical transformation of rubber or the resulting mixture by shedding, molding, pelletizing, etc.

[0012] As used herein, the term “granule” refers to any single, shaped element of a given material and volume. The average size of a granule refers to the maximum dimension of a given granule, and the average is the arithmetic mean. Preferably, the average size of the granules is 0.5 mm to 5 mm, and preferably, no particles have dimensions greater than 10 mm. Alternatively, granules may be defined in relation to the mesh size as defined by EN933-1. In one embodiment, at least 90% by weight of granules will be held by a 0.5 mm sieve, and at least 90% of the granules will pass through a 5 mm sieve.

[0013] Granules can be of any shape, both defined and undefined, similar, different, or random. The granule shape will depend on the manufacturing process and the intended functional performance. In certain embodiments, one or a combination of spherical, cubic, cylindrical, rhomboid, or lenticular shapes may be selected. EN14955:2005 provides criteria for the classification of shapes, within which granules may fall within the ranges of A1, A2, A3, B1, B2, B3, C1, C2, and C3. A value of B2 is generally preferred as a balance between roundness and irregularity, providing resistance to compression while avoiding excessive slip.

[0014] The granules may be the same or different in size and / or shape and properties. In other words, the filler may consist of granules formed to all have the same physical properties, or granules that have different properties due to the presence of different materials, for example. The filler may therefore be a mixture of different biodegradable granules, all of which may contain natural rubber.

[0015] In embodiments, the granules may further comprise an anti-tack agent. The anti-tack agent provides anti-tack properties that prevent individual granules from sticking together during production, storage, and / or use. The use of natural materials as anti-tack agents further ensures that the filler as a whole consists only of natural and / or biodegradable materials. The anti-tack agent may be applied as a coating or dusting to the external portion of the granules, or alternatively, it may be mixed and dispersed throughout the granules during the manufacturing process.

[0016] Filler materials play a role in physically modifying the properties of natural rubber. Depending on the relative amount of filler material to natural rubber, properties such as density, modulus of elasticity, Poisson's ratio, absorption rate, coefficient of friction, etc., can be adapted. Filler materials can also have a significant effect on the processability of the material during the production of filler granules. Those skilled in the art will be well aware of the different fillers that can be used and their effects on these properties. In certain circumstances, fillers can also act as anti-tack agents. Anti-tack agents can also act partially as fillers.

[0017] In one embodiment, the filler material comprises inorganic natural materials. These are materials that exist naturally in nature but are not biodegradable in themselves. Examples may include minerals such as quartz or granite, as well as other materials such as sand, chalk, talc, brick fragments, carbon, and / or charcoal. These materials may be provided in the form of fine particles or powders of any suitable size or grade, ranging from inclusions slightly smaller than granules to fine powders on the nano or micron scale. Those skilled in the art will be well aware of alternative filler materials that can be conceivable for this function. For the purposes of the present invention, it is again emphasized that the presence of such inorganic natural materials in the granules does not alter the fact that the granules as a whole are considered "biodegradable".

[0018] Filler materials may, in addition to or as an alternative to, organic natural materials such as coir fibers, wood chips, cork, corn, coir pith, hemp, or plant waste in powder, particle, or fibrous form. These materials have the advantage of being obtainable through recycling or regeneration processes from a variety of readily available wastes. A further advantage is the absence of microplastics in such natural organic materials, thereby allowing the filler to be used as a whole without the risk of microplastics entering the environment. Other advantages of coir pith, cork, corn, and other similar natural materials are their resistance to aging and tearing, their resistance to adverse weather conditions, and their density sufficient to provide a stabilizing weight to the filler. Furthermore, these materials do not absorb as much heat as polymer fillers, thereby providing a cooler turf system when in use.

[0019] In a further embodiment, the granules may also comprise a binder, which may also be a naturally occurring material. This may preferably be a biodegradable material such as plant starch. This, too, is available from waste and offers the advantage of not containing microplastics. Natural rubber is itself a binder, in that it plays a role in binding fillers together to form stable granules. In this context, references to binders refer to binders other than natural rubber. Those skilled in the art will be familiar with other possible binders, which may include gums, oils, proteins, starches, resins, waxes, and the like.

[0020] As described above, the granules may comprise various relative amounts of natural rubber, filler material, and further optional components, as determined by the required properties. In one embodiment, the granules comprise 10 to 80 wt% of filler and 10 to 50 wt% of natural rubber, more preferably 20 to 40 wt% of natural rubber.

[0021] In certain embodiments, the granules may contain inclusions having a size of 10% to 90% of the granules. In this context, “inclusions” is used to refer to fine particles or objects that are larger than the granules, i.e., smaller than the granules but of a similar order of size. The inclusions may be formed from the same material as the filler material, and their volume may be considered together with the volume of the filler material. In some embodiments, there may be exactly one inclusion per granule.

[0022] In particular, the components may relate to the method of producing the granules. They may be mixed into a precursor material in which the granules are formed, for example, by extrusion. Mixing can be carried out by conventional mixing methods, for example, by using a screw and hopper to deliver each component, and may be done before or during the extrusion process. Alternatively, each granule may have a layer of natural rubber coated on one or more surfaces of the components forming the core of the granule, for example, by a dipping process.

[0023] As described above, anti-tack agents make the granules tack-resistant, preventing individual granules from sticking together during production, storage, and / or use. Preferably, since outdoor sports surfaces can easily reach high temperatures when exposed to sunlight, the resulting granules should be loose and free-flowing at all temperatures at which use is required, especially from -10°C to 80°C. However, fillers for use indoors or under a roof are intended to be sufficiently tack-resistant if they are tack-resistant to temperatures of 50°C.

[0024] In this context, tackiness can be defined as having granules that are not tacky at temperatures below 50°C, more preferably below 60°C, more preferably below 70°C, and most preferably below 80°C. Tackiness for this purpose is evaluated by heating a sample in a dish (with a layer thickness of about 5 mm) in an oven overnight at the relevant temperature. The sample is then cooled and the granules are evaluated. If the granules are still loose or can be freed by slight stirring, the sample is judged to be non-tacky. On the other hand, if the granules form a cake, it is judged to be tacky or non-tacky. The highest temperature at which the granules remain non-tacky is indicated as the tackiness temperature.

[0025] According to another aspect of the present invention, the granules are preferably elastic and have a Shore A hardness of 20-90, or 30-70, preferably 40-60, and optionally about 50. Those skilled in the art will be well aware of how the desired range can be achieved by adding the filler material described above. In this context, it should be noted that the elasticity of natural rubber is different from that of vulcanized rubber, where it is the crosslinking property that can significantly affect the rubber performance. Generally, natural rubber without any filler material remains liquid or its viscosity and hardness cannot be measured. When a filler material is added, the hardness will increase. Ideally, the granules will have a hardness close to that of existing synthetic rubber granules used as fillers. Nevertheless, higher hardness values ​​may be expected due to the constraint of using unvulcanized rubber, which requires a larger amount of filler material.

[0026] In this context, it is understood that elasticity refers to the property of a material that can deform when an external force is applied and will naturally return to its original shape when the force is removed. This behavior can be perfectly elastic, which means that when the force is removed, the material quickly returns to its original shape and the material substantially returns all the energy required to deform it. However, it is preferably viscoelastic, which means that the material only slowly returns to its original shape and does not return all the energy required to deform it. In embodiments, the granules exhibit an energy rebound rate lower than that of SBR, preferably less than 40%, measured on an artificial turf system in accordance with FIFA method 13 (Handbook of Test Methods October 2015 Edition - Version 3.1 16 / 03 / 2020).

[0027] The present invention also relates to an artificial turf system comprising a certain amount of filler, as described above or below. It will be understood that the resulting system in which sports can be practiced depends not only on the filler, but also on other factors such as the artificial turf itself and any underlay, shock pad, or substrate under the turf. Additional filler materials can also be combined and mixed with the natural rubber filler.

[0028] In embodiments, the artificial turf system comprises a backing layer and blades of artificial turf standing upright from the backing layer, and the filler is distributed between the blades of artificial turf.

[0029] In a further embodiment, the system may further comprise an additional filler in the form of a certain amount of particulate of a natural material without natural rubber. The additional filler may be provided under the natural rubber filler or may be intimately mixed with the natural rubber filler. The particulate may be an inorganic natural material such as sand, stone, quartz, gravel, etc. The particulate may additionally or alternatively comprise organic natural materials such as coir fibers, wood chips, cork, grains, corn, coir pith, hemp, etc. These materials may be provided in any suitable size or grade depending on whether they are intended to form a layer under the natural rubber filler or are intended to be mixed with the natural rubber filler.

[0030] The present invention also relates to a method for manufacturing filling material granules for artificial turf, the method comprising cold-forming a precursor from a composition comprising natural rubber and a filler material, dividing the precursor into granules, and providing an anti-sticking agent to the granules and the method is carried out without chemical modification of the natural rubber by cross-linking or other means. In this context, cold-forming is intended to denote a process carried out at room temperature without the need for heating of the natural rubber (latex), as is usually the case in an extrusion process involving vulcanized or cross-linked rubber.

[0031] In one embodiment, the anti-sticking agent is provided to the granules prior to dividing the precursor, which can be achieved by providing the anti-sticking agent as a film, coating, or dusting on the precursor during the cold-forming process. In this context, the anti-sticking agent is distinguished from the filler in that its main function is not to strengthen the structure of the granules themselves but to prevent adhesion between the granules. The anti-sticking agent can thus form a layer without being mixed with or completely penetrated by the natural rubber. In certain embodiments, the composition of the granules comprises 20% - 60% filler, 20% - 60% natural rubber, and 10% - 30% anti-sticking agent. In a preferred embodiment, these ratios can be approximately 40 / 40 / 20 with a variation of + / - 5%.

[0032] In another embodiment, the method includes treating the granules with an anti-aging step such as treatment with an antioxidant or exposure to UV light.

[0033] Various cold forming processes can be considered. In one embodiment, the cold forming of the precursor comprises cold extrusion into a sheet or filament. In another alternative embodiment, the cold forming of the precursor comprises coating the core by, for example, a dipping process. The core may comprise a natural fiber rope, and dividing the precursor into granules may then comprise cutting the coated rope into shorter sections. The rope will remain in the granules as inclusions as defined above. The natural fiber rope may be a coir rope, a sisal rope, or a jute rope. In this context, the rope is intended to comprise a spun, twisted, braided, or otherwise yarn or filament. An alternative cold forming process is pelletizing, in which the mixed raw material is delivered to a pelletizing machine. Those skilled in the art are familiar with the pelletizing process in contexts such as animal feed.

[0034] Various hot forming processes can be considered. In one embodiment, the hot forming of the precursor comprises hot extrusion into a sheet or filament.

[0035] Further aspects of the present invention are described in the attached independent and dependent claims. Combinations of features from the dependent and independent claims are not limited to those explicitly described in the claims, but can be any appropriate combination.

[0036] The features and advantages of the present invention will be better understood by referring to the drawings illustrating illustrative embodiments. [Brief explanation of the drawing]

[0037] [Figure 1] This shows a cross-sectional view of the artificial turf system 10 according to an embodiment of the present invention. [Figure 2] A schematic cross-sectional view passing through the granules according to the present invention is shown. [Modes for carrying out the invention]

[0038] The artificial turf system 10 shown in Figure 1 comprises a stabilized subbase 12, an elastic layer 13, a woven artificial turf base 14 having upright pile fibers 16, a sand-stabilizing filler layer 17, and a performance filler layer 15 of fine particles 18 and natural rubber-based granules 19. In the exemplary embodiment, the fine particles 18 and granules 19 are of the same size and shape, with an average size of 4 mm. The fine particles 18 are smooth-gradient river gravel, while the granules 19 are a mixture of natural rubber and filler material manufactured according to the process of Example 1 given below.

[0039] Figure 2 shows a schematic cross-sectional view through the granule 19 of Figure 1. The granule 19 is rounded in the range C2 (C1-C3) according to EN14955:2005 and has an average size of 3 mm. It comprises approximately 30 wt% latex rubber 22, which forms a matrix around coir fibers 24 and wood powder 26. The outer surface 30 of the granule 19 is covered with chalk dusting 28. At the center of the granule 19 is a 1.5 mm grade stone inclusion 32 coated with rubber.

[0040] The above is merely illustrative, and it will be understood that granule 19 may have formulations and structures according to any embodiment of the present invention disclosed herein.

[0041] Furthermore, the terminology used herein for constituent elements should be given a broad interpretation that also encompasses equivalent functions and features. Descriptive terms should also be given the broadest possible interpretation; for example, the term “comprising” as used herein should be interpreted as “consisting at least in part of,” meaning that there may be features other than the one or more features preceded by that term. Related terms such as “comprise” and “comprises” should be interpreted similarly. This description refers to embodiments having specific combinations of features, but it is assumed that further interchangeable combinations and cross-combinations of features between embodiments are possible. Example 1

[0042] Exemplary natural rubber-based fillers were produced and tested as follows: Equal weights of raw liquid latex, coir fibers (ground to a powder with a diameter <0.2 mm), and wood (ground to a powder with a diameter <0.2 mm) were mixed together. The raw latex contained approximately 30% water. After mixing for about 3 hours, coagulation was initiated by adding formic acid (dilution ratio 1:20). The mixture was formed into a sheet approximately 3 mm thick using a press. The sheet was then dried under ambient conditions for 2 days to remove excess water.

[0043] The sheet was then mechanically shredded with the addition of a chalk anti-tack agent to produce granules with sizes ranging from 0.5 mm to 5 mm and shapes ranging from A2 to A3. The granules exhibited excellent elasticity, with a feel similar to existing polymer fillers. Note: Cryogenic shredding was also found to be functional.

[0044] The artificial turf test area was prepared using a 25 mm depth of granules distributed in an artificial turf base with a pile height of 50 mm and a 10 mm stabilizing sand layer. The artificial turf was tested according to the FIFA Handbook of Test Methods October 2015 Edition - Version 3.1 16 / 03 / 2020, and the following results were obtained.

[0045] [Table 1]

[0046] Further testing demonstrated a Shore A hardness of 54, as well as long-term resistance to both freezing and water. Example 2

[0047] In the second hypothetical example, natural latex (10%), coir fibers ground into a powder with a diameter of <0.2 mm (20%), wood ground into a powder with a diameter of <0.2 mm (20%), and calcium carbonate powder (50%) were mixed together. After mixing, the materials were pelletized to form pellets (cylindrical granules) with a diameter of 2 mm and a length of approximately 8 mm (further cut into 2 mm pieces).

[0048] The granules exhibited excellent elasticity, possessing a feel similar to existing polymer fillers. The following is a direct reproduction of the claims as originally filed. [1] A natural rubber-based infill for artificial turf, the infill comprising biodegradable granules, the biodegradable granules comprising natural rubber that is chemically but physically modified by the addition of a certain amount of filler material, and the biodegradable granules having an average size of 0.2 mm to 5 mm. [2] The filler material according to [1], wherein the filler material comprises an inorganic natural material such as at least one of sand, chalk, quartz, brick rubble, and / or charcoal. [3] The filler material according to [1] or [2], wherein the filler material comprises organic natural materials such as coir fibers, wood chips, cork, corn, coir pith, hemp, starch, or plant waste. [4] The filler according to any one of [1] to [3], wherein the biodegradable granules further comprises a binder, preferably a biodegradable material such as plant starch and / or a natural material. [5] The filler according to any one of [1] to [4], wherein the biodegradable granules comprises 10 to 80 wt% filler and 10 to 40 wt% rubber. [6] The filler according to any one of [1] to [5], wherein the biodegradable granules comprises a content having a size of 10% to 90% of the biodegradable granules. [7] The filler according to [6], wherein each granule comprises a layer of natural rubber coated on one or more surfaces of the contents. [8] A filler according to any one of [1] to [7], wherein an anti-tack agent is provided, optionally mixed and dispersed in the biodegradable granules. [9] The biodegradable granules are loose and free-flowing at a temperature of -10°C to 80°C, as described in any one of [1] to [8].

[10] The biodegradable granules have a Shore A hardness of 20 to 90, preferably 40 to 60, and optionally about 50, as described in any one of [1] to [9].

[11] An artificial turf system comprising the amount of infill material specified in any one of items [1] to

[10] .

[12] The artificial turf system according to

[11] , further comprising a backing layer and blades of artificial turf standing upright from the backing layer.

[13] The artificial turf system according to

[11] or

[12] , wherein the filler further comprises a certain amount of fine particles of a natural material that does not contain natural rubber.

[14] A method for producing infill granules for artificial turf, Cold molding a precursor from a composition comprising natural rubber and filler material, The aforementioned precursor is divided into granules, To provide an anti-sticking agent to the granules mentioned above. A method comprising, wherein the method is carried out without chemical modification of the natural rubber by crosslinking or other means.

[15] The precursor is provided with the anti-tack agent prior to dividing the precursor into granules, the method according to

[14] .

[16] The method according to

[14] or

[15] , wherein the granules are the anti-tack agent mixed with the precursor.

[17] The method according to any one of

[14] to

[16] , wherein the anti-tack agent is a natural absorbent powder such as sand, chalk, quartz, brick rubble, charcoal, or cornstarch.

[18] The method according to any one of

[14] to

[16] , comprising treating the granules with an antioxidant or an anti-aging step such as exposure to UV light.

[19] The method according to any one of

[14] to

[18] , wherein the composition comprises 20% to 60% filler, 20% to 60% natural rubber, and 10% to 30% anti-tack agent, preferably in a ratio of about 40 / 40 / 20.

[20] The method according to any one of

[14] to

[19] , wherein the cold forming of the precursor comprises cold extrusion into a sheet or filament.

[21] The method according to any one of

[14] to

[20] , wherein the cold forming of the precursor comprises coating a nucleus.

[22] The method according to

[21] , wherein the core comprises a natural fiber rope, and dividing the precursor comprises cutting the coated natural fiber rope into shorter sections.

[23] The method according to

[22] , wherein the natural fiber rope is a koir rope, a sisal rope, or a jute rope.

[24] The method according to

[20] , wherein the cold forming is an extrusion through a pelletizing machine for forming cylindrical pellets.

Claims

1. A natural rubber-based infill for artificial turf, wherein the infill comprises biodegradable granules, the biodegradable granules comprising a mixture of 10-60% wt% natural rubber and an anti-tack agent, which are chemically but physically modified by the addition of 10-80 wt% filler material, the filler material comprising an organic natural material including at least one of coir fiber, wood chips, cork, corn, coir pith, hemp, starch, or plant waste, and the biodegradable granules having an average size of 0.2 mm to 5 mm.

2. The filler material according to claim 1, wherein the filler material comprises an inorganic natural material containing at least one of sand, chalk, quartz, brick debris, and / or charcoal.

3. The filler according to claim 1 or 2, wherein the biodegradable granules further comprise a binder containing a biodegradable material and / or a natural material.

4. The filler according to any one of claims 1 to 3, wherein the biodegradable granules comprise a content having a size of 10% to 90% of the biodegradable granules.

5. The filler according to claim 4, wherein each granule comprises a layer of natural rubber coated on one or more surfaces of the contents.

6. The filler according to any one of claims 1 to 5, wherein the anti-tack agent is mixed and dispersed in the biodegradable granules.

7. The filler according to any one of claims 1 to 6, wherein the biodegradable granules are loose and freely flowing at a temperature of -10°C to 80°C.

8. The biodegradable granules have a Shore A hardness of 20 to 90, as described in any one of claims 1 to 7.

9. An artificial turf system comprising an amount of infill material as described in any one of claims 1 to 8.

10. The artificial turf system according to claim 9, further comprising a backing layer and blades of artificial turf standing upright from the backing layer.

11. The artificial turf system according to claim 9 or 10, wherein the filler further comprises fine particles of natural material that do not contain natural rubber.

12. A method for producing infill granules for artificial turf, A precursor is cold-molded from a composition comprising a mixture of 10-60 wt% natural rubber and 10-80 wt% filler material, wherein the filler material comprises an organic natural material containing at least one of coir fibers, wood chips, cork, corn, coir pith, hemp, starch, or plant waste. The aforementioned precursor is divided into granules, To provide an anti-sticking agent to the granules mentioned above. A method comprising, wherein the method is carried out without chemical modification of the natural rubber by crosslinking or other means.

13. The method according to claim 12, wherein the precursor is provided with the anti-tack agent prior to dividing the precursor into granules.

14. The method according to claim 12 or 13, wherein the granules comprise the anti-tack agent mixed with the precursor.

15. The method according to any one of claims 12 to 14, wherein the anti-tack agent is a natural absorbent powder comprising at least one of sand, chalk, quartz, brick debris, charcoal, or cornstarch.

16. The method according to any one of claims 12 to 14, further comprising treating the granules in an anti-aging step including treatment with an antioxidant or exposure to UV light.

17. The method according to any one of claims 12 to 16, wherein the composition comprises 20% to 60% filler, 20% to 60% natural rubber, and 10% to 30% anti-tack agent.

18. The method according to any one of claims 12 to 17, wherein the cold forming of the precursor comprises cold extrusion into a sheet or filament.

19. The method according to any one of claims 12 to 18, wherein the cold forming of the precursor comprises coating a nucleus.

20. The method according to claim 19, wherein the core comprises a natural fiber rope, and dividing the precursor comprises cutting the coated natural fiber rope into shorter sections.

21. The method according to claim 20, wherein the natural fiber rope is a coir rope, a sisal rope, or a jute rope.

22. The method according to claim 18, wherein the cold forming comprises extrusion through a pelletizing machine for forming cylindrical pellets.

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