Improved method and system for regenerating individual components of a synthetic or artificial turf product

Abstract

The present invention relates to an improved method and system for regenerating the individual components of a synthetic or artificial turf product in a form that closely resembles their original state. This result is achieved by a method divided into three sections: a first section where the turf is compacted and dried, a second section where fillers such as rubber and sand are separated, and a third section where the grass fibers and backing are separated.

Description

[Technical field]

[0001] The present invention relates to an improved method for regenerating individual components of a synthetic or artificial turf product in a form that is nearly identical to their original state. The result is achieved by a method divided into three sections: a first section where the turf is compacted and dried, a second section where fillers such as rubber and sand are separated, and a third section where the grass fibers and backing are separated. [Background technology]

[0002] Synthetic turf has been used as a surface for football, baseball, and soccer fields for many years, and in recent years has been used in other applications where an alternative to natural grass is desired, including at least playgrounds, residential and commercial lawns and other landscaping, paths, paintball fields, tennis courts, putting greens, dog runs, and the like.

[0003] Typically, synthetic turf includes a grass-like fabric with a backing and a number of upstanding ribbons that resemble grass, also called face fibers. Many synthetic turf products also include infill material dispersed between the upstanding ribbons, which may be composed of sand, tire rubber crumbs, or other particulates, either alone or in combination with one another. The infill material mimics the soil of natural turf, acts as ballast, and / or contributes to the physical properties of the turf, such as resiliency, that make the turf suitable for a particular use.

[0004] Synthetic turf has a limited lifespan, depending on the structure of the turf, the application for which it is used, weathering, and how the turf is maintained.

[0005] By way of example, a typical synthetic turf for use as an athletic field may have a useful life of about 8 to 15 years. Large amounts of synthetic turf are currently used on hundreds of athletic fields and other applications.

[0006] Disposal of turf is very costly due to its composition of materials ranging from recycled rubber, sand to plastics. Recycling and reusing all or part of the synthetic turf is an option that has been explored in recent years to avoid sending the turf to landfills at significant cost.

[0007] Methods for recycling carpet and for preparing carpet backing using recycled carpet scrap are known, some of which involve separating the carpet yarn, or tufts, from the backing, for example by cutting, and processing only the yarn.

[0008] However, synthetic turf differs in composition from carpet, and these differences in composition make traditional carpet recycling processes unsuitable for recycling synthetic turf. The majority of carpet products use nylon face fibers, while most current synthetic turf products use polyethylene.

[0009] The primary coating of most carpets is a latex coating, while the coating of most synthetic grass is polyurethane. In the United States, only a small fraction of broadloom carpets contains a coating containing polyurethane, and only a small fraction of synthetic grass has a coating containing latex. Most synthetic grass produced in the past six years has a polyurethane coating applied to the backing. It is believed that polyurethane-coated synthetic grass cannot be recycled in its entirety. This is because the polyurethane coating cannot be recycled efficiently. Polyurethane is a thermoset (as opposed to a thermoplastic), and therefore difficult and expensive to recycle. Nevertheless, the recovery of polyurethane from carpets is described in US 5,185,380, where the backing is scraped, crushed, and subjected to a cyclone classification step to remove rigid foreign components such as metal and PVC, and the non-rigid components are consolidated under high pressure and high temperature to provide a sheet. This method thus provides a new product from a portion of used carpet.

[0010] In turf, a coating is applied to the backing of the tufted material for the purpose of securing the face fibers to the primary backing. An additional coating of hot melt adhesive or polyurethane foam may also be applied. This secondary coating is typically used to attach the secondary backing, which may be polyester or polypropylene.

[0011] Many synthetic turf products contain ingredients not found in carpets that are incompatible with, or at least undesirable in, conventional carpet recycling methods. For example, conventional carpets do not contain fillers. Typical filler materials for synthetic turf installations include sand, tire rubber crumbs, and / or other particulates, either alone or in combination with one another. This makes synthetic turf recycling present unique problems not encountered in carpet recycling.

[0012] Separating the filler from the remainder of the turf may require the use of specialized equipment and there may be environmental concerns associated with disposal of the separated filler. An additional concern in the recycling process is the effect of any remaining filler particulates on the size reduction process and the properties of the final product.

[0013] For this reason, attempts have been made to recycle and reuse existing synthetic turf or at least parts of existing synthetic turf to avoid sending the entire synthetic turf to landfills when it is no longer useful. Such a process is described in WO2010 / 075098, in which the filler is separated from the backing and grass-like fibers, and then the filler is compacted and further removed, and then agglomerated. Granules of the agglomerated turf pieces are placed in an extruder. The granules are extruded to form an extrudate, for example in the shape of a strand or ribbon. Most known processes result in recycling the carpet or turf components into a new product of mixed components, without reverse engineering the product into the individual starting components.

[0014] EP2 096 211 describes another method for disposing of synthetic grass, in which the grass fibers and backing are first separated from the fillers and additional ingredients, which are then subsequently separated in multiple steps. Thus, existing processes can only separate the material to a purity of 95%, which is satisfactory, for example, when the process is for extrusion / compaction to provide a new product. From this, it can be seen that although the prior art process is an improvement over disposing of the material in landfills, there is still a need to further separate the individual parts into fractions substantially comprising one component in order to provide an improved grade of product.

[0015] It is also desirable to provide a flexible process so that the turf and infill composition can be varied.

[0016] It would also be desirable to provide a process whose result is individual components that are purified to a degree sufficient for reuse as turf or in other industries.

[0017] EP 2 862 688, granted to the same applicant, deals with a dry separation process in which the individual components are provided essentially pure. The method comprises three specific separation steps in a specific sequence, thus the separation is based on size, specific gravity, and specific gravity, size, and shape. Usually, when the turf product originates from an athletic field, rubber and / or sand are used as fillers. Although most of the sand and rubber can be easily separated from the rest of the turf product, a significant amount of sand and rubber is still present in the structure. In particular, sand, soil, or gravel must be removed from the polymeric components to improve their usefulness in the same (i.e. artificial turf) or other types of products. Being able to provide a rubber fraction that is essentially pure and also free of sand and / or gravel is necessary for its reuse in the same applications. Separation of fine particles such as sand has proven to be a particularly difficult task. Also, the efficiency of the process remains an area of ​​focus in order to obtain a cost-effective process that will continue to outperform traditional landfilling and incineration as alternatives.

[0018] It is therefore an object of the present invention to further improve the process of effective separation of individual components, and more specifically, to do so, inter alia, by making the separation of fillers more efficient and allowing for providing individual fractions of improved size and quality for reuse. Summary of the Invention

[0019] In a first aspect, these and further objects are solved by a method for processing a synthetic turf product and recovering components thereof, the method comprising an input and compaction section, a filler separation section, and a turf and backing separation section, the input and compaction section being in fluid communication with the filler separation section and the turf and backing separation section; The introduction and miniaturization section is (a) feeding a wet synthetic turf product into a feeding and compacting section; (b) reducing the wet artificial synthetic turf product into compacted turf material, preferably to 120×120 mm or less, and feeding the compacted turf material into a drying unit; (c) drying the compacted turf material in a drying unit, such as a drum dryer, to a moisture content of 5% w / w or less, preferably 3% w / w or less, most preferably 1% w / w or less to form a dried material; (d) separating the dried material by screening in a first sieving unit 103 into at least a first fraction substantially comprising the filler material which is fed into a filler separation section, and a second fraction substantially comprising the grass fibers and backing components; (e) reducing the second fraction, substantially comprising grass fibres and backing components, in a reduction unit to a maximum dimension of at most 50mm, and optionally feeding the further reduced fraction into a first screening unit, such as a drum screen having openings of 4-8mm, preferably 6mm, to provide a small fraction and a large fraction; (f) feeding the further compacted fraction (5) obtained in step (e), or optionally the larger fraction, into a material hopper which, optionally, feeds the further compacted fraction, up to at most 35 mm in its maximum dimension, into a sod and backing separation section in succession; (g) further processing the first fraction obtained in step (d) and, if any, the smaller fraction obtained in step (e) in a packing separation section; Equipped with.

[0020] The drying air temperature in step (c) at the inlet to the drying unit suitably has a temperature in the range of 125 to 250°C, preferably 150 to 230°C, the length of the drying unit is 8 to 15m, preferably 10 to 12m and the compacted turf material is input at a rate in the range of 6 to 10 tonnes per hour, preferably 8 tonnes / hour on a dry basis.

[0021] It is preferable that the ingredients during drying are not melted or agglomerated, as this would deteriorate the quality of the final fraction. Therefore, temperature, time, and size of the ingredients are important factors for optimal drying that will allow for subsequent separation. The feed to be dried consists of sand and rubber, but size is also important, as carpet must also be dried to release the integrated filler without melting. Typically, carpet ingredients have the lowest melting temperature.

[0022] When the drying unit is a drum dryer, it is operated at a speed of 1200 to 1600 rpm, preferably 1400 rpm.

[0023] Once the feed has been properly prepared by downsizing, drying, and initial separation, it is possible in subsequent sections to separate the individual components to the required high purity and in sufficiently high yields to enable a cost-effective process.

[0024] The filler separation section is i) feeding the first fraction obtained in step d) and the small fraction obtained in step e) into a main sieving means having three sieving means, namely a first sieving means, a second sieving means having openings of 0.5-1.5 mm, and a third sieving means having openings of 0.1-6 mm. the first sieving means is a grid-type sieving means having perforations, the longest dimension of the perforations being 3-6 mm, thereby providing four fractions, namely an upper fraction, first and second middle fractions, and a lower fraction, the first middle fraction being further processed for rubber recovery, and the second middle fraction being further processed for sand recovery.

[0025] The primary screening step separates most of the sand from the rest of the ingredients. Sand is the largest component of the turf product by weight. The first screening means further separates the rubber from the backing and turf. This step would therefore make possible the more difficult task of being able to provide pure rubber.

[0026] Another challenge in recovering ingredients of turf products is to be able to separate the ingredients at a rate and volume over the available sieving area. Thus, in an embodiment, one or more of the sieving means, preferably on the upper sieving means such as the first sieving means, are provided with at least one baffle. It is also contemplated that baffles are present on sieving means in other sieving units in addition to the main sieving unit.

[0027] The baffles help to distribute the feed over the area of ​​the sieving means, thereby improving the sieving capacity over the time that the feed is conveyed through the various sieving means. It is preferred that at least one baffle is positioned at an angle (α) in the range of 30-60°, preferably 40-50°, for example 45° to the horizontal plane of the sieving means, and that at least one baffle is mounted in the middle section of the sieving means, preferably on a horizontal line between ¼ and ¾ of the length of the sieving means.

[0028] As the feed moves over the sieving means from the inlet to the outlet, the natural movement of the flow will cause the material to move towards the edges of the sieving means, however, when the baffles are positioned at a specified angle within a specified area of ​​the sieving means, the feed is distributed evenly across the entire area, thereby improving overall separation.

[0029] It is contemplated that each sieving means may have two or more baffles, for example, 2, 3, 4, or 5 baffles. The number of baffles may be determined based on the area of ​​the sieving means. From this, the number of baffles required for optimal separation increases with the area of ​​the sieving means.

[0030] After the main sieving step, the first intermediate fraction is ii) feeding the first intermediate fraction into a second sieving unit having three sieving means, namely a first sieving means having openings between 1.2 and 3.5 mm, a second sieving means having openings between 0.8 and 2.5 mm, and a third sieving means having openings between 0.5 and 2.0 mm, thereby providing four fractions; iii) feeding each of the four fractions obtained from the second screening unit into a first set of four individual separating means to provide four low density fractions comprising the lining material and rubber and a combined high density fraction comprising additional components such as stones, where the separating means separate by specific gravity using air and in a first rubber recovery step, the heavy materials such as stones are separated from the mixed fractions. This will allow a higher degree of separation of the rubber from other materials. The stones can be reused and sold if they do not contain rubber. iv) feeding each of the four low density fractions into a second set of four individual separating means to provide a combined low density fraction comprising the backing material and a second combined high density fraction comprising the rubber, wherein the separating means separate by gravity using air, and further wherein the second combined high density fraction comprising the rubber is recovered or further processed in a rubber grinding unit; Further processing for rubber recovery by In this second rubber recovery step, the rubber, now a heavy fraction, is separated from the mixed fraction with the lining material, which will allow the rubber to be further refined and processed into separate rubber fractions of different sizes.

[0031] The combined low density fraction with the backing material is v) separating by specific gravity and size by providing an upwardly directed air flow in a separator configured to cause a swirling motion in which the lighter fraction is entrained upwards in the air flow and the heavier fraction is allowed to fall downwards, wherein the lighter fraction comprises a lining material and the heavy fraction comprises additional material such as stones, the stone fraction may be mixed with the heavy fraction obtained in step v; In step vi), the lighter fraction comprising the backing material is subjected to a third sieving step in a third sieving unit having two sieving means, namely a first sieving means with openings between 2 and 5 mm and a second sieving means with openings between 0.8 and 3 mm, thereby providing three fractions, namely a top fraction comprising grass fibres, a middle fraction comprising the backing and a bottom fraction comprising rubber, optionally the top fraction being returned to the third compacting means and further processed in the grass and backing separation section; In step vii), each of the middle and bottom fractions is fed into a third set of two individual separating means to provide a second combined low density fraction comprising turf material and a third combined high density fraction comprising a mixture of rubber and backing, wherein the separating means separate by gravity using air; They are then subjected to further

[0032] By adding these separation steps, the grass fibers and rubber, two of the most valuable components for reuse, are provided in substantially pure quality.

[0033] The fraction substantially comprising sand is separated in a second part of the filler separation section, in order to provide in particular pure sand. Thus, the method further comprises: viii) feeding the second intermediate fraction into a fourth sieving unit having four sieving means to provide five fractions, wherein the sieving means have perforations in the range of 1.2-0.2 mm, the size of the openings decreasing from the top to the bottom; ix) feeding each of the five fractions into a fourth set of five individual separating means to provide a second set of low density fractions comprising rubber, sand, and / or fine fiber particles and a fourth combined high density fraction comprising sand, wherein the separating means separate by gravity using air, wherein the fraction comprising sand is recovered; The method may further comprise a step of processing the second intermediate fraction obtained in step i) for separation of sand and rubber by filtration.

[0034] Each of the second set of five low density fractions comprising rubber, sand, and / or fine fiber particles is fed in step x) to a fifth set of five individual separating means to provide low density and high density fractions as defined below, where the separating means separate by specific gravity using air.

[0035] When 30% vol / vol or more of the second set of low density fractions is rubber, a third combined light fraction comprising rubber is provided, and a fourth combined heavy fraction comprising a mixture of sand and rubber is provided, the heavy fractions being recycled to a fourth screening unit in step viii); When less than 30% vol / vol of the second set of low density fractions is rubber, a fifth combined heavy fraction comprising sand is provided, and a fourth combined light fraction comprising a mixture of rubber and sand is provided, the sand is recovered, and the mixture of rubber and sand may be further processed or discarded.

[0036] In a further step ix), sand is first recovered and the next step is decided based on the presence of rubber in the fraction. In this way, the process can be flexibly customized for compositions where the rubber is above or below 30% vol / vol. This has been shown to result in the purest fraction of either sand or rubber. The remaining mixed fraction can then be discarded or further processed if the plant has unused capacity at a given point in time, such as in the post-filler wash section.

[0037] This branching of the fractions is important because obtaining perfectly pure rubber is essential to be able to sell the fractions at a sustainable price.

[0038] Further processing and separation of the rubber may be carried out by inputting one or more of the rubber fractions obtained throughout the process, such as the second combined high density fraction obtained in step iv) and / or the third combined light fraction obtained in step x), when comprising rubber, in embodiments where 30% vol / vol or more of the second set low density fraction is rubber.

[0039] The fractions are further processed by feeding one or more of the rubber fractions (14,22) into a fifth sieving unit (212) having three sieving means, namely a first sieving means having openings between 1.5 and 4 mm, a second sieving means having openings between 0.7 and 1.5 mm, and a third sieving means having openings between 0.2 and 0.7 mm, thereby providing three separate rubber fractions (29a-29c) and a dust fraction (30).

[0040] In the above variant, the fifth sieving step may be preceded by feeding one or more of the rubber fractions into a unit capable of beating fine particles so as to dislodge them from the rubber particles, such as a hammer mill, and feeding the mixture thus beated into the fifth sieving unit.

[0041] It may be desirable to have a buffer tank at a particular location to allow the entire process to be run in a continuous manner at a certain speed. Thus, in an embodiment, the buffer tank, if present, is in fluid communication with a unit capable of beating fine particles off of the rubber particles, such as a hammer mill, and the buffer tank receives the resulting rubber fraction throughout the process.

[0042] To increase the yield or minimize waste from the process, it is desirable to include in the process and system a post-filler wash section in which one or both of the heavy fraction comprising rubber, stone and optionally sand obtained in step v) and the combined high density fraction obtained in step iii) are further processed, the post-filler wash section comprising: xii) feeding one or both of the heavy fraction comprising rubber, stones and optionally sand and the combined high density fraction into a sieving step in a sixth sieving unit having two sieving means, namely a first sieving means having openings between 0.4 and 3 mm and a second sieving means having openings between 0.2 and 2 mm, thereby providing three fractions, namely a top fraction, a middle fraction and a bottom fraction; vii) feeding each of the three fractions into a sixth set of three individual separating means to provide a fifth combined low density fraction comprising rubber and a sixth combined high density fraction comprising stones and sand, wherein the separating means separate by specific gravity using air, and further wherein the rubber, in an embodiment where 30% vol / vol or more of the second set low density fraction is rubber, is recovered or further processed in the rubber grinding section, such as by feeding into a buffer tank or mixing with one or all of the second combined high density fraction obtained in step iv) and / or the third combined light fraction obtained in step x), when comprising rubber; Therefore, by adding this step, the yield of the rubber fraction is further increased and the overall process waste is reduced.

[0043] In parallel with the filler separation route, the input and compaction section is also connected to a sod and lining separation section, in which the large fractions obtained in steps f) and g) are further compacted to at most 35 mm in the largest dimension and separated by specific gravity and size by providing an upwardly directed air flow in a second separator configured to cause a swirling motion in which the second lighter fraction is entrained upwards in the air flow and the second heavy fraction is allowed to fall downwards, where the second lighter fraction substantially comprises the grass fiber component and the second heavy fraction substantially comprises a mixture of the lining material and the grass fiber component, and in a further step h), the second lighter fraction substantially comprising the grass fiber component is input into a second screening unit, preferably a drum screen, with openings of 1-3 mm in the shortest dimension to provide a final small fraction comprising the lining and grass fiber waste and a final large fraction comprising the sod (35). The final large fraction comprising the turf is recovered in step i) in a post-processing section (500) to optionally further process the turf, which is the most valuable part of the plastic fraction when reused.

[0044] According to all embodiments and steps, when using a separator configured to create a swirling motion in which the lighter fractions are entrained upwards in the air stream and the heavier fractions are allowed to fall downwards, the unit is in a preferred embodiment a cyclone separator or a zigzag air sifter. When separation is carried out in a zigzag air sifter, air is provided at a frequency of 18-27 Hz, more preferably 20-25 Hz. Tests have been carried out at various frequencies above and below the above ranges, and it has been surprisingly found that the best separation is obtained within the disclosed range, with the best results being obtained at about 20-25 Hz.

[0045] As the size of the mixed components becomes smaller and smaller, the task of separating the turf / grass fibers from the backing becomes more and more difficult. This leads to the fact that as the size decreases, the difference in weight of the individual components becomes closer. On the other hand, compaction is a necessary measure to make it possible to break down the various components of the turf material. Thus, compaction at certain points in the separation has proven effective because the otherwise problematic components have been substantially separated in previous steps.

[0046] There is also provided a system for processing a wet synthetic turf product in a continuous manner to provide individual components of the synthetic turf product, the system comprising an input and compaction section, a filler separation section, and a sod and backing separation section, the input and compaction section being in fluid communication with the filler separation section and the sod and backing separation section, the input and compaction section comprising an inlet for the wet synthetic turf product connected to a compaction unit such as a shredder, the outlet of the compaction unit being connected to a drying unit, the outlet of the drying unit having two outlets, a first outlet connected to the filler separation section and a second outlet capable of compacting the components to at most 50 mm in their maximum dimension. The first screening unit is connected to a first sieving unit having a first outlet connected to a second compaction unit, the outlet of the second compaction unit being connected to a material hopper, optionally through a first screening unit such as a drum screen having openings of 4-8 mm, preferably 6 mm, the first screening unit having two outlets, namely a first outlet, retentate, and a second outlet, filtrate, wherein the first outlet is connected to the material hopper, which continuously supplies the retentate fraction to a third compaction unit, preferably a cutting mill, the outlet of the third compaction unit being connected to a sod and backing separation section, and the second outlet, filtrate, being connected to a filler separation section.

[0047] The process and system according to the invention are configured for continuous processing in three main sections: the input and compaction section, the filler separation section, and the sod and backing separation section. The post-filler wash section can be connected to the filler separation section as required by allowing the flow of the various fractions as explained above. [Brief description of the drawings]

[0048] [Figure 1] 1 is an illustration of the system and method of the present invention. [Diagram 2] 1 is an embodiment of the injection and compaction section of the present invention. [Diagram 3] 1 is an embodiment of a first portion of a packing separation section of the present invention. [Figure 4] 1 is an illustration of a second portion of the packing separation section of the present invention. [Diagram 5] 1 is an illustration of an optional post-filler wash section of the present invention. [Figure 6] 1 is an illustration of a turf and backing separation section of the present invention. [Figure 7] Figures 7a and b show a partial perspective view of an embodiment of a grid-like sieving means of a sieving unit according to the invention, respectively a detail of the embodiment of Figure 7 and a detail of a slightly different embodiment of a grid-like sieving means of a sieving unit according to the invention. [Figure 8] 1 shows an embodiment of a screening means with a windbreaker / baffle according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] In the context of the present invention, essentially pure means that one component constitutes more than 95% (w / w) of the fraction. Even more preferably, more than 96% (w / w), more than 97% (w / w), more than 98% (w / w), more than 99% (w / w), or about 100%. In any case, essentially pure means that the fraction in question is pure enough for reuse.

[0050] As used herein, the term "ingredient" refers to one type of fraction of the starting product, such as sand, rubber, polyethylene (PE), etc. The term should not be limited to ingredients derived from a particular part of the turf material / product, but rather defined by its type of chemical composition.

[0051] As used herein, the term "synthetic / artificial turf product" contemplates all components of the starting materials used in the process of the present invention. Synthetic and artificial may be used interchangeably and may have the same meaning, i.e., a grass-like product made from non-biological materials.

[0052] The starting material for the process of the present invention is turf products originating from sports facilities, playgrounds, landscaped areas, and the like. The origin of the material should not be limited. It is also contemplated that the material may comprise contaminants. The starting material is moist. The moisture content varies from place to place. The present invention should not be limited to a particular moisture content of the starting material.

[0053] Synthetic turf products typically include at least a backing material, a filler, and a turf / grass fiber component.

[0054] In the context of the present invention, the term "backing material" contemplates one or more layers for holding grass fiber components. Thus, the term backing material includes, but is not limited to, materials to which artificial grass fibers are tufted, woven, knitted, or otherwise attached. The term backing material also contemplates secondary backings or coatings, or fastener components for fastening pieces of turf products to one another or to a surface.

[0055] In the context of the present invention, the term "grass fiber component" or "turf" contemplates fibers or yarns that are textured or non-textured, tufted, woven, knitted, or otherwise attached to a backing material. The backing and grass fiber components may be made of the same or different materials.

[0056] In the context of the present invention, the term "filler" contemplates rubber, sand and "additional ingredients."

[0057] In the context of the present invention, the term "additional ingredients" contemplates any material provided in the turf product not otherwise provided for. Thus, additional ingredients may include, but are not limited to, waste material, soil, etc., captured in the turf carpet, etc.

[0058] The synthetic turf product may also preferably comprise a thatch or "thatch zone" consisting of one or more thatching materials connected to the backing material, such as by weaving, gluing, melting, or any suitable means for attaching the thatching material to the backing material. Thatching of synthetic turf is well known in the art and is described in several documents, such as US 6,299,959 and WO 2004 / 042149. In the context of the present invention, the materials that make up the thatch, thatch zone, and / or thatch, if present, are typically made of the same materials as the grass fiber material, and are therefore included in the term "grass fiber material."

[0059] Typically, synthetic turf products include a backing fabric and a plurality of upstanding ribbons that resemble grass, also called face fibers or yarns, and in the context of the present invention, the face fibers or yarns are examples of grass fiber components according to the present invention.

[0060] Typically, the grass fiber component is made from polyethylene, polypropylene, or blends thereof. The grass fiber may also be made from nylon or any other material known in the art, alone or in combination with polypropylene and / or polyethylene.

[0061] These grass fiber components are typically tufted or sewn into a primary backing material that can be made from different materials including, but not limited to, polypropylene and polyester. The driving factor in the selection of materials for the backing as distinct from grass fiber, among others, is primarily cost.

[0062] A coating material may be applied to the grass fibers and primary backing to hold the grass fibers in place.

[0063] The primary coating of most synthetic turf products includes polyurethane and typically includes a coating filler such as calcium carbonate or coal fly ash. The primary coating may also include latex, hot melt adhesives, and / or thermoplastics in addition to or in place of polyurethane.

[0064] The synthetic turf product may also have a secondary backing or coating that can be made from a number of different materials, including but not limited to polypropylene and polyester.

[0065] The collected synthetic turf product containing the waste material has the following approximate composition: the grass fiber component typically constitutes about 5-10 wt%, the backing typically constitutes about 5-10 wt%, and the filler typically constitutes up to 80 wt%.

[0066] In the context of the present invention, percentages are by weight unless otherwise stated.

[0067] The grass fiber component may include polyethylene, polypropylene, nylon, or other materials, alone or in combination.

[0068] In some embodiments, the grass fibers comprise a blend of polypropylene (PP) and polyethylene (PE). In further embodiments, the grass fibers comprise a blend of PE, or a blend of PP, PE, and nylon.

[0069] The primary backing may include polyester, polypropylene, polyethylene, and other materials alone or in combination, such as polyethylene alone or blends of PP and polyester.

[0070] The coating may include polyurethane, latex, hot melt adhesives, and / or thermoplastics, alone or in combination. Suitable hot melt adhesives include, but are not limited to, Reynolds 54-041, Reynolds 54-854, DHM 4124 (The Reynolds Company PO Greenville, SC, DHM Adhesives, Inc. Calhoun, GA).

[0071] Suitable thermoplastics include, but are not limited to, polypropylene, polyethylene, and polyester. The coating may also include a coating filler, which may be coal fly ash, calcium carbonate, iron oxide, or barium sulfate, or any other filler known in the art.

[0072] Synthetic turf products include filler materials dispersed amongst upstanding ribbons of grass fibers, which contribute to the physical properties of the turf product that make it suitable for particular uses.

[0073] The synthetic turf infill may be made from any material suitable to provide the desired physical properties, and the infill may be selected from, but is not limited to, one or more of sand, gravel, cork, coconut shells, polymer beads, and rubbers, including but not limited to crumb rubber, ethylene propylene diene monomer (EPDM) rubber, thermoplastic elastomers (TPE), and neoprene rubber, either alone or in combination. Most often, the infill is rubber and sand. In certain embodiments, the infill material is rubber or sand. In another particular embodiment, the infill material is rubber and sand.

[0074] The present invention has been described in an embodiment in which the filler is sand and rubber. However, it is contemplated that the filler may be comprised of any of the above materials. Thus, when comprised of two materials other than sand and rubber, in the specification and claims, the material having the lowest density should replace rubber, and the material having the highest density should replace sand.

[0075] In a preferred embodiment, the synthetic turf product further comprises one or more thatching materials connected to the backing material. The thatching materials are typically made of the same material as the grass fiber component, polypropylene, or nylon.

[0076] When the artificial turf field is removed from the site, it is usually cut into 50m x 50m pieces and rolled up. The rolls are transported to where they are to be further processed, whether that be to a landfill or a facility for recycling the product.

[0077] The thus divided turf field, i.e., wet artificial turf product, is provided to the process of the present invention in rolls, typically having a diameter of 2-5 m and a width of 1-2 m. The size of the turf product when it arrives at the processing facility can be any size and the present invention should not be limited by the size of the incoming turf. The size of the turf product is limited only by practical handling.

[0078] In the following, an embodiment of the process will be described with reference to Figures 1 to 8. The present invention should not be limited to the embodiment described below.

[0079] The process of the present invention will now be described in more detail with reference to FIG. 1, which illustrates sections of the system and process in their most general form.

[0080] The method and system comprises an input and compaction section 100, a filler separation section 200, the filler separation section comprises two parts, the method and system comprises a sod and backing separation section. Sections 100, 200, and 300 are connected as described in further detail herein. Processing in section 100 can occur independently of sections 200 and 300, and processing in sections 100 and 200 can occur independently of sections 100 and 300. The system further comprises a post-filler washing section 400 following the filler separation section 200, and a post-sod processing section 500 following the sod and backing separation section 300. However, processing in the input and compaction section is essential as a feed for the ability of the subsequent sections to provide fractions with the required yield and purity. The input and compaction section 100, the filler separation section 200, and the sod and backing separation section are designed to allow the process and system to process materials in a continuous manner. For this purpose, buffer tanks may be placed to allow the feeding back of certain fractions from downstream parts of the process to certain parts upstream. Thus, the present system and process is specifically designed to allow such continuous processing to provide a cost-effective process that can be run throughout the day and night if material is available. The post-washing sections 400 and 500 may be used as part of a continuous separation process or may be used to increase the yield of various intermediate fractions and run as a batch process. The nature of the turf post-processing section 500 depends on the particular market or demand and may be any one of agglomeration, spheronization, or extrusion.

[0081] With further reference to Figure 1, the input and size reduction section 100 generally comprises a first size reduction step / unit 101, a drying step / unit 102, a first sieving step / unit 103, a second size reduction step / unit 104, a first optional screening step / unit 105, and an optional third size reduction step 106. An embodiment of the input and size reduction section is shown in more detail in Figure 2.

[0082] The purpose of the dosing and compaction section is to reduce the size of the artificial turf roll to a manageable size that can be dried sufficiently to allow for the subsequent sections of the process, i.e., separation, without adversely affecting the polymer. This is an important balance, since the large amount of sand present can absorb heat that can adversely affect plastics and rubbers. Also, turf products have components of very different sizes, and therefore it can be difficult to dry the various components sufficiently. Thus, the present invention solves the problem of balancing between size, material type, time, and temperature required to be able to provide fractions to the subsequent sections that can be separated as desired.

[0083] The filler separation section 200 in the first portion generally comprises a main screening sieving step / unit 201, a second sieving step / unit 202, a first density separation step / set of density units 203 (203_1-4), a second density step / set of density units 204 (204_1-4), a first step / means for separating by specific gravity and size 205 (such as a zigzag sieve), a third sieving step / unit 206, and a third density separation step / set of two density units 207 (207_1 and 2).

[0084] The filler separation section 200 in the second part generally comprises a fourth sieving step / unit 208, a third density step / set of five density units 209 (209_1-5), a fourth density separation step / set of five density units 210 (210_1-5), the second part may also include a step / means for vibrating the rubber fraction 211, such as a hammer mill, and a fifth sieving step / unit 212.

[0085] In the broadest sense, the system according to the present invention comprises an input and compaction section 100, a filler separation section 200, and a sod and backing separation section 300, connected as illustrated in Figure 1. In some embodiments, the system may also include a post-filler cleaning section 400 and / or a post-sod processing section 500.

[0086] An embodiment of the packing separation section is shown in more detail in FIGS.

[0087] The purpose of the first part of the filler separation section is to screen and separate the stones from the rubber, the rubber from the turf, and the backing from the rubber. The focus is to provide a pure rubber material as well as remove the stones from the turf fiber material that is recycled to the third compaction step / unit 106.

[0088] The second part of the filler separation step has two purposes. The first purpose is to separate the rubber from the sand to provide pure sand and potentially increase the rubber yield. The second purpose is to separate the pure rubber into a separate, now upcycled, saleable fraction and eliminate contamination with undesirable small particles as there is no market for these in the final product.

[0089] The sod and backing separation section 300 requires the third compaction step 106 to be mandatory and generally comprises a second step / means for separating by specific gravity and size 301 (such as a zigzag screen) and a second screening step / unit 302. An embodiment of the sod and backing separation section is shown in more detail in Figure 5.

[0090] The purpose of the grass and lining separation section is to separate the grass and lining from each other while removing any fine particles. This will provide separate plastic type fractions of different qualities that can be upcycled for different purposes.

[0091] The post-filler wash section 400 generally comprises a seventh sieving step / unit 401 and a fourth density separation step / set of density units 402 (402_1-3). An embodiment of the post-filler wash section is shown in more detail in FIG.

[0092] The purpose of the post-filler wash is to extract additional valuable materials, such as rubber, stone, and sand, from the unfinished product that would otherwise be inseparable, hence the main purpose of this section is to increase the yield of the fractions.

[0093] This process will now be described in greater detail, and although Figures 2-6 will be described with reference to the process, it will be understood that all descriptions apply equally to the present system.

[0094] FIG. 2 is a detailed illustration of an embodiment of the injection and compaction section 100 .

[0095] In a first step, the artificial turf product 1 is input and comminuted in a first comminuter step 101, which in the embodiment shown is a shredder 101, which comminutes the turf product to a size of approximately 120x120mm. The comminuted turf material 2 is input to a drying unit 102, which in the embodiment shown is a drum dryer 102. It is contemplated that further already comminuted material may also be input to the drum dryer, as illustrated as input stream 1_b. A suitable means, such as a material hopper, is suitably used to ensure that material is input in the volume and rate required to operate the drying unit in the desired manner.

[0096] For best results, the compacted turf material 2 is fed at a rate of 6-10 tonnes per hour, preferably 8 tonnes per hour on a dry basis. The length of the drying unit 102 is 8-15 meters, preferably 10-12 m. When the drying unit is a drum dryer, it is operated at a speed of 1200-1500 rpm, preferably 1400 rpm. The temperature at the inlet of the drying unit is in the range of 125-250°C, preferably 150-230°C.

[0097] The moisture content of the material after the drying step is at most 5% w / w, preferably less than or equal to 3% w / w, even more preferably less than or equal to 1% w / w. Having such a low moisture content in all processes / units downstream from the drying unit is essential in order to be able to achieve a good separation, in particular between the sand and the rubber.

[0098] The dried material 3 is screened through a first sieving unit 103 having 5mm openings, thereby providing two fractions, a first fraction 4a substantially comprising filler material and a second fraction 4b substantially comprising a mixture of turf and backing material, wherein the length of the greatest dimension is 5-7mm or more, for example 6mm or more.

[0099] After this initial separation, the first and second fractions 4a and 4b are further processed independently.

[0100] The first fraction 4a, which substantially comprises the filler, is further processed in a filler separation section 200, which will be described in more detail with reference to Figures 3 and 4. It is contemplated that there will be a silo for adding additional dry filler to the first fraction 4a prior to entering the filler separation section. Such material may come from a downstream process.

[0101] The second fraction 4b is further reduced in the granulator 104 in the embodiment shown, in order to give a smaller fraction 5, in which the size of the largest dimension is at most 50 mm. This step may be preceded by an iron removal step, in which magnetic metals trapped in the carpet are removed. The fraction 5 thus further reduced may optionally be subjected to a heavy waste separation step, in which heavy contaminants such as stones may be removed from the carpet. Such a step may be a separation by specific gravity and size in a zigzag screen or air sifter 107. The further reduced fraction 5 is then screened in a first screening unit 105, illustrated as a drum screen, to provide a small fraction 6a comprising the remaining filler and a large fraction 6b comprising the turf and backing, the large fraction 6b being fed into the turf and backing separation section 300. The small fraction 6a is fed into the filler separation section and is optionally mixed with the first fraction 4a. It is contemplated that the first screening unit is not required and the further compacted fraction 5 may be fed directly to a sod and backing separation section or to a third compaction step in a cutting mill 106, as described below.

[0102] The first screening means, i.e., drum screen 105, has openings of 4-8 mm, preferably 6 mm. As illustrated in the embodiment, the large fraction 6b is fed into a material hopper that can ensure a continuous supply of sod and backing. It is also contemplated that the large fraction is further compacted in a third compaction step to provide a sod and backing fraction 7 with a maximum dimension of at most 35 mm, as illustrated, which is a cutting mill 106 in the illustrated embodiment. It is contemplated that the sod and backing fraction from the downstream process can be recycled and mixed with the large fraction 6b before the cutting mill 106, as illustrated, although this recycling is optional and can be omitted.

[0103] In a preferred embodiment, the first screening step / unit is omitted.

[0104] With reference to FIG. 3, a first embodiment of a packing separation section according to the present invention will now be described in more detail.

[0105] In the illustrated embodiment, the first fraction 4a and the minor fraction 6a, if present, are optionally premixed and, in some embodiments, are fed to a buffer tank (not shown) for holding the filler, as illustrated, to allow for continuous feeding of the stream throughout the process. From the optional buffer tank, the filler separated feed fraction 8 is fed to a main sieving unit 201 having three sieving means 201_a-c. The first sieving means 201_a has perforations and a length of 3-6 mm in the longest dimension, the first sieving means being preferably a grid type sieving means as further illustrated in Figures 7a and 7b. The second sieving means 201_b has openings of 0.5-1.5 mm, and the third sieving means has perforations of 0.1-6 mm. Four main sieving fractions are provided (9a-d) and a lower fraction 9d, i.e. the dust fraction, is collected. The top fraction 9a is further processed for separation of rubber, turf and lining. The second intermediate fraction 9c is further processed in the second part of the filler separation section, as will be described in detail with reference to Figure 4. The first intermediate section 9b is also further processed for rubber recovery in the second part of the filler separation section, i.e. the rubber grinding section 200a.

[0106] The first sieving means of the main sieving unit is preferably provided with at least one baffle designed to ensure uniform distribution of the material to be sieved over the entire area of ​​the sieve. This is important to maintain the speed of the continuous separation. Each sieving means is preferably provided with 1, 2, 3 or 4 baffles. Each baffle is positioned at an angle α of 30 to 60°, preferably 40 to 50°, even more preferably 45° with respect to the horizontal plane of the framework of the sieving means.

[0107] The one or more baffles are positioned in the middle section of the sieving means, preferably between 1 / 4 and 3 / 4 of the length of the sieving means. This is important because the natural flow of the filler due to the slight inclination of the sieving means of about 5-10 degrees will be forced to move towards the edge of the sieving means in the middle section in the sieving direction. Therefore, for optimal flow, the baffles are positioned in a horizontal plane in the middle 50% of the length of the sieving means. The length of the baffles is typically 3 / 4 of the height of the sieving means and 1 / 2 of the width of the sieving means. The shape and position of the baffles are described in more detail below, particularly with reference to FIG. 8.

[0108] It is also contemplated that the further sieving means of the main sieving unit and the further sieving unit or all the sieving means are provided with such baffles.

[0109] The first intermediate section 9b is then fed into a second sieving unit 202 having three sieving means, namely a first sieving means having openings of 1.2-3.5 mm, a second sieving means having openings of 0.8-2.5 mm, and a third sieving means having openings of 0.5-2.0 mm, thereby providing four fractions 10a-d. Each of the four fractions 10a-d is fed into a first set of four individual separating means 203_1-4, where the separating means separate by specific gravity using air, to provide four low density fractions 11a-11d comprising lining material and rubber, and a combined high density fraction 12 comprising additional components such as stones. Each of the four low density fractions 11a-11d is fed into a second set of four individual separating means 204_1-4 that separate by specific gravity using air to provide a combined low density fraction 13 comprising the backing material and a combined high density fraction 14 comprising the rubber, which is recovered or further processed in a rubber polishing unit 200a, which will be described with reference to FIG. 4.

[0110] The combined low density fraction 13 comprising the backing material is separated by specific gravity and size by providing an upwardly directed airflow in a separator 205 configured to create a swirling motion, in the embodiment shown, the separator 205 is a zigzag air shifter 205. Here, the lighter fraction 15 is rolled upward in the airflow and the heavier material is allowed to fall downward, the lighter fraction 15 comprising rubber, backing, and turf material, and the heavy fraction 16 comprising additional material such as stones, which may be combined with the high density fraction 12 as illustrated. The stones may be sold as is. However, if fraction 12+16 of the stones comprises a rubber component, fractions 12 and 16 will be fed into a filler post-processing section 400.

[0111] The lighter fraction 15 comprising rubber, lining and turf material is sieved in a third sieving unit 206 having two sieving means, a first sieving means with openings between 2 and 5 mm and a second sieving means with openings between 0.8 and 3 mm, thereby providing three fractions, a top fraction 17 comprising grass fibers, a middle fraction 18 comprising lining and a bottom fraction 19 comprising rubber. In the embodiment shown, the top fraction 17 is returned to the cutting mill 106 and further processed in a turf and lining separation unit 300. Each of the middle fraction 18 and bottom fraction 19 is fed into a third set of two individual separating means 207_1 and 207_2, where the separating means separate by specific gravity using air, to provide a second combined low density fraction 20 comprising turf material and a third combined high density fraction comprising a mixture of rubber and lining.

[0112] With reference to Figure 4, an embodiment of the second part of the filler separation section according to the invention will now be described in more detail. The second intermediate fraction 9c obtained from sieving in the main sieving unit 201 is further processed for sand and rubber separation. The second intermediate fraction 9c is separated in a fourth sieving unit 208 having four sieving means with openings in the range of 1.2 or 0.8-0.2 mm, the size of the openings decreasing from the top to the bottom.

[0113] The particular selection of openings of the various sieving means in this and other sieving units may be selected for optimal separation using the methods described in WO2021 / 048214 to the same applicant.

[0114] Sieving in the sieving unit 208 provides five fractions 21a-21e. Each of the five fractions 21a-21e is fed into a fourth set of five individual separating means 209_1-5, where the separating means separate by specific gravity using air, to provide a second set of low density fractions 22a-22e comprising rubber, sand, and / or fine fiber particles, and a fourth combined high density fraction 23 comprising sand. The sand is collected and reused as appropriate. After the first separation of the sand from the rubber and sand fractions, each of the five low density fractions 22a-22e comprising rubber, sand, and / or fine fiber particles is fed into a fifth set of five individual separating means 210_1-5, where the separating means separate by specific gravity using air, to provide a second low density fraction and a second high density fraction.

[0115] According to the method, the flow is directed such that, in the illustrated embodiment, when 30% vol / vol or more of the low density fractions 22a-22e is rubber, density separation results in a third combined light fraction 24 comprising rubber, which is sent to a rubber polishing unit 200a for further sorting and, optionally, premixed with the rubber fraction 14.

[0116] A fourth combined heavy fraction 25 comprising a mixture of sand and rubber is also provided. This second heavy fraction 25 is recycled to the fourth screening unit 208 as part of the particle stream.

[0117] On the other hand, when less than 30% vol / vol of the second set of low density fractions 22a-22e is rubber, a second heavy fraction 26 comprising sand is provided. This sand is optionally collected and reused and appropriately mixed with the fifth combined high density fraction 23 comprising sand. In addition, a fourth combined light fraction 27 comprising a mixture of rubber and sand is provided. This mixture of rubber and sand can be further processed, for example, in a post-filler washing section unit, held in a buffer tank, or disposed of as appropriate to ensure a continuous flow of material.

[0118] Diversion of the stream to the appropriate conveying means is accomplished by having a diversion means, such as a valve, positioned at the outlet of the second set of density separation means. Suitable valves are standard diverter valves, either mechanically / electrically or manually operated.

[0119] In the rubber grinding portion 200a of the filler separation section, the rubber is separated into distinct sizes. The rubber fractions 14 and 24 are fed into a unit capable of beating fine particles away from the rubber granules, in the embodiment shown, a hammer mill 211. The effect of this step is to beating the fine particles away from the rubber granules. Given the moisture content of the material, the fine particles are released from the rubber, resulting in a beating mixture 28 of rubber and suspended fine sand particles. The beating step can be preceded by an iron removal unit. Also, an intermediate buffer tank 213 is preferably located before the hammer mill 211 to accommodate the continuous processing of the material. Thus, when present, the buffer tank is in fluid communication with the unit capable of beating fine particles away from the rubber granules 211, here the hammer mill, and the buffer tank receives the rubber fractions obtained throughout the process, such as the rubber fractions 14 and 24 obtained upstream.

[0120] It is contemplated that both the buffer tank and the unit capable of beating the fine particles so as to dislodge them from the rubber granules are omitted. This is preferred for simpler separation. In this embodiment, the rubber feed is fed directly into the fifth screening unit 212.

[0121] From this, it is provided that the optionally beaten rubber and sand fines mixture 28 is then fed into a fifth sieving unit 212 having three sieving means, namely a first sieving means having openings of 1.5-4 mm, a second sieving means having openings of 0.7-1.5 mm and a third sieving means having openings of 0.2-0.7 mm, thereby providing three separate rubber fractions 29a-29c which are collected and reused accordingly. Additionally, a dust fraction 30 is provided.

[0122] When one or more of fractions 12 and 16 comprise rubber, the optionally combined fractions are further processed to recover the stone and rubber for further end use. This processing takes place in a post-filler processing section 400. This section is not always part of a continuous flow, but can be included if and when further separation of the stone and rubber is required. At downtime, this section can be used to separate fractions in various so-called waste fractions generated throughout the process in order to increase yields and hence minimize the total waste of the process.

[0123] In the embodiment shown, the combined high density fraction 12 and heavy fraction 16 are fed into a sixth sieving unit 401 having two sieving means, namely a first sieving means with 0.4-3 mm openings and a second sieving means with 0.2-2 mm openings, thereby providing three fractions 31a-31c, namely an upper fraction 31a, a middle fraction 31b, and a lower fraction 31c. Each of the three fractions 31a-31c is fed into a sixth set of three individual separating means 402_1-402_3, where the separating means separate by specific gravity using air, to provide a fifth combined low density fraction 32 comprising rubber and a sixth combined high density fraction 33 comprising stones and sand. The rubber fraction 32 is recovered or further processed in the rubber polishing section 200a.

[0124] The sod and backing are separated in the sod and backing separation section 300, the separation being achieved by feeding the large fraction 7 obtained in the feeding and densifying section and further densified to at most 35 mm in its maximum dimension, the fraction thus densified being separated according to specific gravity and size by providing an upwardly directed air flow in a second separator 301 configured to cause a swirling motion in which a second lighter fraction 33 is entrained upwards in the air flow and a second heavier fraction 34 is allowed to fall downwards, where the second lighter fraction 33 substantially comprises a grass fiber component and the second heavy fraction substantially comprises a mixture of backing material and grass fiber component. The grass fibres, which are the highest upcycle quality plastic, are then further concentrated by feeding the second lighter fraction 33, which substantially comprises the grass fibre components, into a second screening unit 302, preferably a drum screen, with openings of 1-3 mm in the shortest dimension, to provide a final small fraction 36 comprising lining and grass fibre waste, and a final large fraction comprising turf 35. The final large fraction comprising turf 35 can be recovered or further processed in a post-processing section 500.

[0125] The openings of the second screening unit are elongated in a preferred embodiment, which will further concentrate and purify the larger grass fiber fraction.

[0126] In all the above descriptions, if the separator is configured to create a swirling motion in which the lighter fractions are entrained upwards in the air stream and the heavier fractions are allowed to fall downwards, the unit is preferably a cyclone separator or a zigzag air sifter, and when the separation is carried out in a zigzag air sifter, the air is provided at a frequency of 18-27 Hz, more preferably 20-25 Hz.

[0127] Two embodiments of the grid sieving means 700 are further illustrated in Fig. 7 and in expanded view in Fig. 7a and 7b. First referring to Fig. 7 and 7a, it can be seen that a grid slot is formed between two sections in each perforation 701 of the grid sieving means 700, the lower section of the perforation in Fig. 7a protruding downwards with respect to the general plane defined by the grid sieving means, and the upward section protruding upwards with respect to the general plane, so that the grid slot formed in each perforation 701 is symmetrical about an axis lying in the general plane of the grid sieving means 700. In another embodiment shown in Fig. 7b, the upward section is formed in substantially the same shape as in the embodiment of Fig. 7 and 7a, but the lower section extends substantially in the general plane of the grid sieving means 700.

[0128] The positioning of the grid sieving means 700 within the system is shown in Figure 3, where one grid sieving means 700 of a stack of sieving means is shown in the main sieving unit 201. The slight tilt of the grid sieving means 700 is also shown in Figure 3.

[0129] The configuration of the individual sieving means of the various sieving units of the system may be selected as described.

[0130] The sieving means is referred to as a grid sieving means 700 having the features, for example, as described above and shown in Figures 7, 7a and 7b, although other configurations of the sieving means are contemplated.

[0131] An example of such a generic sieving means 800 is shown in Figure 8, which also illustrates the configuration and position of the baffles mentioned above, here shown as three baffles 801. In the embodiment shown, the angle α formed between each baffle 801 and a respective line in the horizontal plane of the sieving means 800 is approximately 45°.

[0132] 8 also shows the formation of a stack of sieving means, shown in dashed lines below the sieving means 800. As in the embodiment described above, the sieving means 800 can be positioned slightly inclined in the flow direction. The inclination can vary between the sieving means of the various sieving units, just as the inclination can be selected individually for the sieving means of the stack in a sieving unit.

[0133] In a second aspect, a system for separating synthetic or artificial turf products is provided, the system being configured as detailed in the process above. In its most general sense, the system is for processing a wet synthetic turf product in a continuous manner to provide the individual components of the synthetic turf product, the system comprising an input and compaction section (100), a filler separation section (200), and a sod and backing separation section (300), the input and compaction section (100) being in fluid communication with the filler separation section (200) and the sod and backing separation section (300); The input and compaction section (100) comprises an inlet for the wet artificial turf product (1), connected to a compaction unit (101), such as a shredder, the outlet of which is connected to a drying unit (102), the outlet of which is connected to a first screening unit (103) having two outlets, namely a first outlet connected to the filler separation section (200) and a second outlet connected to a second compaction unit (104) capable of compacting the components to a maximum dimension of at most 50 mm, the outlet of the second compaction unit (104) being connected to a first sieving unit (103) having two outlets, namely a first outlet connected to the filler separation section (200) and a second outlet connected to a second compaction unit (104) capable of compacting the components to a maximum dimension of at most 50 mm, the outlet of the second compaction unit (104) being connected to a second ... sieving unit (103) capable of compacting the components to a maximum dimension of at most 50 mm, the outlet of the second compaction unit (104) being connected to a second sieving unit (103) having two outlets, namely a first outlet connected to the fill The inlet is connected to a first screening unit (105), such as a drum screen, having openings of 4-8 mm, preferably 6 mm, the first screening unit having two outlets, namely a first outlet, retentate, and a second outlet, filtrate, where the first outlet is connected to a material hopper which continuously feeds the retentate fraction to a third compaction unit (106), preferably a cutting mill, the outlet of the third compaction unit (106) is connected to a sod and backing separation section (300) and the second outlet, filtrate, is connected to a filler separation section (200).

[0134] All embodiments and variants described with reference to the process apply equally to the present system and vice versa.

[0135] Key to the process and system is the order of the separation steps and, in a further embodiment, the parameters of the separation steps. Different separation orders, unit combinations and parameters result in inferior end products, i.e. fractions with substantial amounts of other components and / or contaminants, which makes this fraction less suitable for use as a high-grade recycled product.

[0136] Thus, the present invention also provides recycled components of artificial turf products, more specifically recycled sand, recycled rubber, recycled grass fibre components and recycled backing materials obtained or obtainable by the process according to the present invention.

[0137] The components are characterized by a purity of greater than 95% (w / w) of the fraction, even more preferably greater than 96% (w / w), greater than 97% (w / w), greater than 98% (w / w), greater than 99% (w / w), or about 100% of the fraction.

[0138] Grass products often comprise components of different colors, and therefore the resulting fractions can be visually evaluated to assess purity. For example, the purity of rubber and grass fibers can be evaluated using standard tests in the art, such as D5603 and E1131-08 from ASTM International for testing the purity of rubber and plastics. Additionally, purity can be determined by manually or mechanically separating portions of the components, determining the weight percentages, and extrapolating.

[0139] The products or fractions obtained by the process of the present invention are useful as starting materials in several industries such as, but not limited to, the rubber molding industry, the construction industry, the synthetic turf industry, and the plastic extrusion industry.

[0140] Thus, in another aspect, the present invention can be viewed as a process for providing a starting material in the manufacture of rubber tiles, rubber mats, rubber flooring, plastic pellets, and plastic boxes, the process comprising the steps and variations as outlined above, and the product obtained by any of the above. Thus, another aspect of the present invention is the use of a fraction selected from one or more of sand, rubber, grass fiber components, and backing materials, each fraction being separately obtained by the process of the present invention, in any of the industries mentioned above.

[0141] The separator, which operates by separating by gravity and size by providing an upwardly directed air flow configured to create a swirling motion, can be any suitable means in the art, such as a cyclone separator, e.g., Hovex De-Sanding Cyclone from Gea AG, a zigzag air sifter, e.g., ZZS Air sifter from Trenn- und Sortiertechnik GmbH, or similar separating means.

[0142] The zigzag sieve can be an air sifter type ZZS180 / 800 available from Trenn- und Sortiertechnik GmbH, in which the swirling motion is caused by injecting an air stream a into a zigzag channel in the sorting channel. The air is provided at a frequency of 25 Hz. Other suppliers of zigzag sieves are available, such as Hamos GmbH, Penzberg, Germany. In the following tests, the zigzag sieve / air sifter separator is a ZZS air sifter available from Trenn- und Sortiertechnik GmbH, in which the swirling motion is caused by a zigzag channel in the sorting channel, hence the name.

[0143] Suitable separation means that can be used for gravity separation (density separation) can be obtained from Trenn- und Sortiertechnik GmbH or Guidetti Srl, Renazzo, Italy.

[0144] Suitable sieving units according to the invention are TTS Separating Tables No. TTSS900 / 1000 / 1 and TTS600 / 1000 / 1 available from Trenn- und Sortiertechnik GmbH.

[0145] A suitable miniaturization tool is a cutting mill of the type H500 / R2-2000 available from Hosokawa Alpine AG, but may be obtained from other suppliers such as Amis Maschinen Vertriebs GmbH, Zuzenhausen, Germany.

[0146] Suitable shredders and drum screens are components commonly known in the art and the selection of a particular unit is within the skill of one of ordinary skill in the art. The particular shredder used in the tests was model H500 / R2-2000 available from Erdwich Zerkleinerungs-Systeme GmbH.

[0147] It is also contemplated that magnets may be inserted at various points in the process to remove magnetic components or contaminants, preferably positioned prior to the various cutting steps to avoid destroying the blade.

[0148] It should be understood that the process and system of the present invention also includes the necessary means for transporting, depositing, holding, directing, opening, closing, etc. of the fractions. Some, but not all, of these are illustrated in the drawings, but the present invention should not be limited to these specific units or locations unless otherwise stated. These are standard means known in the art.

[0149] The method and system according to the present invention can process approximately 8 tons / hour to 192 tons / hour, 24 hours a day. example

[0150] In the following, embodiments of the present invention are illustrated with respect to fraction recovery and waste reduction compared to prior art processes. Tests followed the process of sections 100, 200, and 300, but the weight processed was slightly less than a full size field, specifically, the process was stopped after collecting 100 tons and then extrapolated to the expected tonnage of a full batch of 155 tons, as shown in the table below. Therefore, the results are extrapolated, but it would not be practical to run a full batch for comparison purposes in order to have the same amount of material.

[0151] Prior to running the selected portion of the test field, all equipment was emptied to ensure that only material from the selected field was included in the separation process. All big bags containing the various fractions were weighed, data was collected, and the distribution of all fractions was calculated.

[0152] The table compares a commercially operating facility with extrapolated results from a pilot facility when using the method of the present invention.

[0153] Table 1

[0154] [Table 1]

[0155] Table 2

[0156] [Table 2]

[0157] As can be seen, the amount of non-separated fraction (bold fraction) that would otherwise be discarded is reduced by 13.27 percentage points, which in the given example corresponds to 20.63 tons less waste.

[0158] Considering the large volumes, the method of the present invention has proven a surprising advantage over existing processes, whereby throughput and yield have been increased while purity has been maintained at the desired and required high levels.

[0159] This is a significant improvement in the critical quest to provide economically viable solutions to global waste management challenges.

[0160] A further advantage of the present invention is the ability to separate rubber fillers of different densities. This is a significant improvement over prior art processes since reuse of mixed density rubber has proven to be less useful.

[0161] From an economy of scale perspective, the process of the present invention provides a business case for a 50% increase in profits, as exemplified below.

[0162] Table 3

[0163] [Table 3]

[0164] In addition, pure fractions were obtained. As an example, below, various sand fractions were analyzed for purity. The remaining fractions were analyzed for purity according to the standard recited methods as detailed above. The obtained purity of these fractions was at a similar level and as described in the detailed description.

[0165] The purity of the sand was determined by subjecting a weighed sample to an incineration step according to standard ash testing methods, where the material is typically heated above 500°C for two hours, thereby decomposing all organic material, after which the sample is weighed again. Purity is calculated based on the weight difference.

[0166] The fractions analyzed were fractions 23 (Table 4) and 26 (Table 5) illustrated in FIG.

[0167] Table 4

[0168] [Table 4]

[0169] Table 5

[0170] [Table 5]

[0171] The results show that the purity of almost all the various sand fractions is above 99.50%.

[0172] Hence, in addition to high yields, high purity is also achieved according to the present invention.

[0173] The unburned samples may be further analyzed for soil quality to determine the chemical composition of the contaminants and allow for classification of the sand / soil for end use.

Claims

1. A method for processing a synthetic turf product (1) and recovering its components, said method comprising an input and compaction section (100), a filler separation section (200), and a turf and backing separation section (300), said input and compaction section (100) in fluid communication with said filler separation section (200) and said turf and backing separation section (300); The input and downsizing section (100) comprises: (a) feeding a wet synthetic turf product (1) into said feeding and compacting section (100); (b) compacting the wet artificial synthetic turf product (1) into compacted turf material (2), preferably to a size of 120 x 120 mm or less, and feeding the compacted turf material into a drying unit (102); (c) drying the compacted turf material (2) in the drying unit (102), for example in a drum dryer, to a moisture content of 5% w / w or less, preferably 3% w / w or less, most preferably 1% w / w or less, to form a dried material (3); (d) separating said dried material (3) by screening in a first sieving unit (103) into at least a first fraction (4a) substantially comprising filler material which is fed into said filler separation section (200) and a second fraction (4b) substantially comprising grass fibres and backing components; (e) reducing said second fraction (4b), substantially comprising grass fibres and backing components, in a reducing unit (104) to at most 50 mm in its largest dimension, and optionally feeding the further reduced fraction (5) into a first screening unit (105), such as a drum screen with openings of 4-8 mm, preferably 6 mm, to provide a small fraction (6a) and a large fraction (6b); (f) feeding the further compacted fraction (5) obtained in step (e), or the larger fraction (6b), if present, into a material hopper which, optionally, feeds the further compacted fraction to at most 35 mm in its maximum dimension into the sod and backing separation section (300) in succession; (g) further processing the first fraction (4a) obtained in step (d) and, if present, the smaller fraction (6a) obtained in step (e) in the packing separation section (200); A method comprising:

2. 2. The method of claim 1, wherein in the drying step (c) the drying air temperature at the inlet of the drying unit has a temperature in the range of 125-250°C, preferably 150-230°C, the length of the drying unit (102) is 8-15m, preferably 10-12m, and the compacted turf material (2) is input at a rate in the range of 6-10 tonnes per hour, preferably 8 tonnes / hour on a dry basis.

3. The method according to claim 2, wherein the drying unit (102) is a drum dryer operated at a speed of 1200 to 1600 rpm, preferably 1400 rpm.

4. The packing separation section (200) comprises: i) feeding the first fraction (4a) obtained in step d) and the small fraction (6a) obtained in step e) into a main sieving means (201) having three sieving means (201_a-c; 700; 800), namely a first sieving means (201a_1), a second sieving means (201_b) having openings between 0.5 and 1.5 mm, and a third sieving means (201_c) having openings between 0.1 and 6 mm. The method according to any one of claims 1 to 3, wherein the first sieving means (201_a) is a grid-type sieving means (700) having perforations (701) with a longest dimension of 3 to 6 mm, thereby providing four fractions (9a-d), namely an upper fraction (9a), first and second intermediate fractions (9b and 9c) and a lower fraction (9d), wherein the first intermediate fraction (9b) is further processed for rubber recovery and the second intermediate fraction (9c) is further processed for sand recovery.

5. 5. The method according to claim 4, wherein one or more of said sieving means (700; 800) is provided with at least one baffle (801), preferably on said first sieving means (201_a).

6. 6. The method according to claim 5, wherein at least one said baffle (801) is positioned at an angle (α) in the range of 30 to 60°, preferably 40 to 50°, e.g. 45° with respect to the horizontal plane of the sieving means (800), and wherein at least one said baffle (801) is mounted in a mid-section of the sieving means, preferably on a horizontal line between ¼ and ¾ of the length of the sieving means.

7. The method according to claim 5 or 6, wherein each sieving means (800; 201_a-c) has two or more baffles (801), such as 2, 3, 4 or 5 baffles (801).

8. The first intermediate fraction (9b) comprises ii) feeding said first intermediate fraction (9b) into a second sieving unit (202) having three sieving means, namely a first sieving means having openings between 1.2 and 3.5 mm, a second sieving means having openings between 0.8 and 2.5 mm, and a third sieving means having openings between 0.5 and 2.0 mm, thereby providing four fractions (10a-d); iii) feeding each of the four fractions (10a-d) obtained from the second screening unit (202) into a first set of four individual separating means (203_1-4) to obtain four low density fractions (11a-d) comprising lining material and rubber and a combined high density fraction (12) comprising additional components such as stones, wherein the separating means separate by specific gravity using air; iv) feeding each of the four low density fractions (11a-d) into a second set of four individual separating means (204_1-4) to obtain a combined low density fraction (13) comprising a backing material and a second combined high density fraction (14) comprising rubber, wherein the separating means separate by gravity using air, and further wherein the second combined high density fraction (14) comprising rubber is recovered or further processed in a rubber grinding unit (200a); The method according to any one of claims 4 to 7, wherein the rubber is further processed for rubber recovery by

9. The low density fraction (13) combined with the backing material comprises: v) separating by gravity and size by providing an upwardly directed air flow in a separator (205) configured to create a swirling motion in which the lighter fraction (15) is entrained upwards in the air flow and the heavier fraction (16) is allowed to fall downwards, wherein the lighter fraction (15) comprises a backing material and the heavier fraction (16) comprises additional material such as stones; vi) subjecting said lighter fraction comprising the backing material to a third sieving step in a third sieving unit (206) having two sieving means, namely a first sieving means with openings between 2 and 5 mm and a second sieving means with openings between 0.8 and 3 mm, thereby providing three fractions, namely a top fraction comprising grass fibres (17), a middle fraction comprising the backing (18) and a bottom fraction comprising rubber (19), wherein optionally said top fraction (17) is returned to a third compacting means (106) for further processing in said grass and backing separation section (300); vii) feeding each of said middle fraction (18) and said bottom fraction (19) into a third set of two individual separating means (207_1+2) to obtain a second combined low density fraction (20) comprising turf material and a third combined high density fraction comprising a mixture of rubber and backing, wherein said separating means separate by gravity using air; The method of claim 8 , further comprising:

10. The second intermediate fraction (9c) obtained in step i) is viii) feeding said second intermediate fraction (9c) into a fourth sieving unit (208) having four sieving means to obtain five fractions (21a-21e), wherein said sieving means have perforations in the range of 1.2-0.2 mm, the size of said openings decreasing from top to bottom; ix) feeding each of said five fractions (21a-21e) into a fourth set of five individual separating means (209_1-5) to obtain a second set of low density fractions (22a-22e) comprising rubber, sand, and / or fine fiber particles and a fourth combined high density fraction (23) comprising sand, wherein said separating means separate by gravity using air, wherein said fourth combined high density fraction (23) comprising sand is recovered; x) feeding each of said second set of five low density fractions (22a-22e) comprising rubber, sand, and / or fine fiber particles into a fifth set of five individual separating means (210_1-5) to provide a low density fraction and a high density fraction, wherein said separating means separate by specific gravity using air; when 30% vol / vol or more of said second set of low density fractions (22a-22e) is rubber, a third combined light fraction (24) comprising rubber is provided, and a fourth combined heavy fraction (25) comprising a mixture of sand and rubber is provided, said heavy fraction (25) being recycled to said fourth screening unit (208) in step viii), 10. The method of any one of claims 4 to 9, wherein when less than 30% vol / vol of the second set of low density fractions (22a-22e) is rubber, a fifth combined heavy fraction (26) comprising sand is provided and a fourth combined light fraction (27) comprising a mixture of rubber and sand is provided, the sand (26) being recovered and the mixture of rubber and sand (27) may be further processed or discarded.

11. Any one of the rubber fractions (14, 24) is 11. The method according to any one of claims 4 to 10, wherein the one or more rubber fractions (14, 22) are further processed by feeding them into a fifth sieving unit (212) having three sieving means, namely a first sieving means having openings between 1.5 and 4 mm, a second sieving means having openings between 0.7 and 1.5 mm and a third sieving means having openings between 0.2 and 0.7 mm, thereby providing three separate rubber fractions (29a-29c) and a dust fraction (30).

12. 12. The method according to claim 11, wherein a fifth screening step is preceded by feeding one or more of the rubber fractions (14, 22) into a unit capable of beating fine particles so as to leave the rubber particles (211), such as a hammer mill, and feeding the thus-beaten mixture (28) into the fifth screening unit (212).

13. 13. The method according to claim 11 or 12, wherein a buffer tank (213) is in fluid communication with said unit, such as a hammer mill, capable of beating fine particles so as to break them out of the rubber granules (211), said buffer tank (213) being charged with the rubber fraction (14, 24) obtained according to any one of claims 1 to 12.

14. One or both of the heavy fraction (16) comprising rubber, stones and optionally sand and the combined high density fraction (12) are further processed in a post-filler washing section (400), which comprises: xii) feeding one or both of said heavy fraction (16) comprising rubber, stones and optionally sand and said combined high density fraction (12) into a sieving step in a sixth sieving unit (401) having two sieving means, namely a first sieving means having openings between 0.4 and 3 mm and a second sieving means having openings between 0.2 and 2 mm, thereby providing three fractions, namely a top fraction (31a), a middle fraction (31b) and a bottom fraction (31c); vii) feeding each of the three fractions (31a-31c) into a sixth set of three individual separating means (402_1-3) to obtain a fifth combined low density fraction (32) comprising rubber and a sixth combined high density fraction (33) comprising stones and sand, wherein the separating means separate by specific gravity using air, and further wherein the rubber is recovered or further processed in a rubber polishing section (200a).

15. The turf and backing separation section (300) comprises: g) separating the large fraction (7) obtained in step f), further reduced in size according to specific gravity and size to at most 35 mm in its maximum dimension, by providing an upwardly directed air flow in a second separator (301) configured to cause a swirling motion in which a second lighter fraction (33) is entrained upwards in the air flow and a second heavy fraction (34) is allowed to fall downwards, wherein the second lighter fraction (33) substantially comprises a grass fiber component and the second heavy fraction substantially comprises a mixture of a backing material and a grass fiber component; h) feeding said second lighter fraction (33) substantially comprising grass fiber components into a second screening unit (302), preferably a drum screen, having openings with a shortest dimension of 1-3 mm, to obtain a final small fraction (36) comprising lining and grass fiber waste and a final large fraction (35) comprising grass; i) recovering said final large fraction (35) comprising turf in a post-processing section (500) and optionally further processing said turf; The method according to any one of claims 1 to 14, comprising:

16. The method according to any one of claims 9 to 15, wherein the separator (205, 301) configured to create a swirling motion in which the lighter fractions are entrained upwards in the air flow and the heavier fractions are allowed to fall downwards is a cyclone separator or a zigzag air sifter, and when the separation is performed in a zigzag air sifter, the air is provided at a frequency of 18-27 Hz, more preferably 20-25 Hz.

17. A system for processing a wet synthetic turf product in a continuous manner to provide individual components of the synthetic turf product, said system comprising an input and compaction section (100), a filler separation section (200), and a sod and backing separation section (300), said input and compaction section (100) in fluid communication with said filler separation section (200) and said sod and backing separation section (300); The input and compacting section (100) comprises an inlet for the wet artificial turf product (1), connected to a compacting unit (101), such as a shredder, the outlet of which is connected to a drying unit (102), the outlet of which is connected to a first sieving unit (103) having two outlets, namely a first outlet connected to the filler separation section (200) and a second outlet connected to a second compacting unit (104) capable of compacting components to a maximum dimension of 50 mm, the outlet of which is optionally a sieving unit having openings of 4-8 mm, preferably 6 mm. The system further comprises a first screening unit (105), such as a drum screen having a first outlet, i.e. a first outlet, retentate and a second outlet, filtrate, connected to a material hopper (105b), said first outlet being connected to said material hopper (105b) which continuously supplies a retentate fraction to a third compaction unit (106), preferably a cutting mill, the outlet of which is connected to said sod and backing separation section (300) and the second outlet, the filtrate, is connected to said filler separation section (200).

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