Method for obtaining rubber-based powder

Abstract

A method for obtaining a rubber-based powder (1) from a rubber-containing product or article, in which at least one rubber layer of a rubber-containing product or article is comminuted and disintegrated by spraying at least one high-pressure water jet onto the rubber layer to obtain said powder, said method being characterized in that said water jet is delivered at a pressure of about 1500-3500 bar, said water jet being delivered at a pressure of about 500-3500 bar, and said rubber-based powder (1) is obtained from a rubber-containing product or article. The water jet is ejected from a conveying part of a rotating head, the rotating head rotates at a rotating speed of about 500-3000 revolutions per minute, and the feeding speed of the rotating head relative to the surface (or vice versa) of the rubber layer to be crushed and disintegrated is about 1-9 centimeters per second (preferably 5-7 centimeters per second); and the distance between the conveying point of the water jet and the surface of the rubber layer to be crushed and disintegrated is about 10-35 mm.

Description

Technical Field

[0001] This invention relates to a method for obtaining rubber-based powder from rubber-containing products or articles.

[0002] The present invention also relates to a method for obtaining rubber-based powder from tires (preferably from end-of-life tires).

[0003] The present invention also relates to a method for obtaining rubber-based powder from rubber conveyor belts, rubber belts, rubber tracts, rubber carpets, rubber flooring, rubber pipes, rubber protective pads, or generally from products or articles containing only, primarily, or even lesser amounts of rubber.

[0004] This invention relates to rubber-based powder obtained by the method described above.

[0005] The present invention relates to rubber-based powder obtained by mechanically pulverizing a rubber-containing product or article (preferably tires, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber tubes, rubber protective pads, or generally any other product or article that contains only, primarily, or even lesser amounts of rubber).

[0006] This invention relates to rubber-based powder obtained from tires (preferably from end-of-life tires). In particular, this invention relates to rubber-based powder obtained by pulverizing tires (preferably end-of-life tires).

[0007] The present invention also relates to a rubber-based compound for tires. Background Technology

[0008] The disposal of end-of-life tires (ETL) is a globally significant issue in terms of environmental sustainability and waste recycling. Currently, the most commonly used technologies for recycling end-of-life tires are extremely energy-intensive and therefore harmful to the environment. Furthermore, the materials obtained from dismantling end-of-life tires, or more precisely, the materials themselves, do not enhance the value of the precious rubber.

[0009] According to Article 228 of Decree DL152 / 2006, in Italy, as in other EU countries, manufacturers and importers are responsible for managing end-of-life tires, and the number of end-of-life tires should be equal to the number they put on the market.

[0010] According to Ecopneus data on Italy, the number of scrapped tires collected in 2020 was 350,538 tons, equivalent to 91% of the statutory target.

[0011] Currently, there are two main methods for recycling end-of-life tires: - Energy recovery is based on the calorific value of rubber, making it a fuel as good as coal. Its primary use is in cement plants, followed by waste-to-energy and pyrolysis.

[0012] - Material recycling focuses on shredding tires to obtain granules of various sizes that can be reused in various industrial sectors (primarily the sports sector); among the technologies employed, room temperature granulation is the most widely used in Italy, followed by desulfurization (chemical, physical, or biological methods), water jet cutting, electrothermal methods, and cryogenic granulation.

[0013] Considering material recycling and the materials obtained from the various processes mentioned above, it is important to emphasize that metals and / or fibers, which account for only 5% of the waste weight, can easily find a way out in material-to-material recycling processes (iron goes to the foundry, and fibers are reused in the production of any synthetic materials), while the reuse of rubber materials remains complex.

[0014] In material recycling, while some of the aforementioned technologies can separate the materials that make up tires (rubber, metal, and / or fibers), there are still no large-scale processes and products that utilize secondary raw materials, thus failing to create an economically and environmentally sustainable market. All currently known products and processes are unsustainable and can only be sustained by end-of-life tire taxes.

[0015] Therefore, as can be seen from the management of end-of-life tires in Italy, even today, the majority of these are still used for energy recovery, specifically 59% of the total; then we must consider the amount recovered in Italy and the amount exported to foreign cement plants (43%). Simple calculations show that 111,845 tons of end-of-life tires are used for energy reuse, of which 48,093 tons are sold to foreign markets.

[0016] Furthermore, given the well-known damage that tire combustion causes to human health and the environment, it is easy to understand how far we are from fully realizing the value of rubber derived from end-of-life tires.

[0017] In this context, it is known to use high-pressure water jets to break up the vulcanized rubber layer of a tire, thereby obtaining regular particles with a basic spherical shape or whatever kind of basic spherical shape after an expensive micronization process.

[0018] It is also known that the granules thus obtained are used in the production of tire rubber compounds. In particular, these granules are currently used as a substitute for carbon black, and the amount of these granules used is typically about 3%-5% of the amount of carbon black typically used in the same compound.

[0019] Furthermore, the known types of rubber granules used to produce tire rubber compounds are unsatisfactory because they cannot adhere properly and stably to the interior of the rubber compound.

[0020] For example, Wang Zefeng et al.'s "Multiresponse optimization of process parameters in water jet pulverization via response surface methodology" and Bowles AJ et al.'s "Sustainable rubber recycling from waste tires by waterjet: anovel mechanistic and practical analysis" describe obtaining rubber granules from mechanically pulverized tires.

[0021] Purpose of the invention The purpose of this invention is to provide a method for obtaining rubber-based powder from rubber-containing products or articles, which can at least partially overcome the above-mentioned disadvantages of conventional solutions.

[0022] Another object of the present invention is to provide a method for obtaining rubber-based powder, which can be implemented in a simple, rapid and low-cost manner.

[0023] Another object of the present invention is to provide a method for obtaining rubber-based powder, which is an alternative and improvement to conventional solutions.

[0024] Another object of the present invention is to provide a method for obtaining rubber-based powder that is highly environmentally friendly.

[0025] Another object of the present invention is to provide a method for obtaining rubber-based powder from tires (preferably from scrap tires), which can at least partially overcome the above-mentioned disadvantages of conventional solutions.

[0026] Another object of the present invention is to provide a method for obtaining rubber-based powder from tires, which can be implemented in a simple, rapid and low-cost manner.

[0027] Another object of the present invention is to provide a method for obtaining rubber-based powder from tires, which is an alternative and improvement to conventional solutions.

[0028] Another object of the present invention is to provide a method for obtaining rubber-based powder from tires, which is highly environmentally friendly.

[0029] Another object of the present invention is to provide a rubber-based powder obtained from rubber-containing products or articles, which can at least partially overcome the above-mentioned disadvantages of conventional solutions.

[0030] Another object of the present invention is to provide a rubber-based powder obtained from tires (preferably from scrap tires) that can at least partially overcome the aforementioned disadvantages of conventional solutions.

[0031] Another object of the present invention is to provide a powder that can stably adhere to the interior of a rubber compound.

[0032] Another object of the present invention is to provide a powder that is alternative and improved compared to known solutions.

[0033] Another object of the present invention is to provide a powder that can be obtained from tires (preferably from end-of-life tires) in a simple, rapid and low-cost manner.

[0034] Another object of the present invention is to provide a tire compound that is highly environmentally friendly.

[0035] Another object of the present invention is to provide a tire compound that, although it includes recycled components obtained from end-of-life tire processing, has structural and functional characteristics substantially equivalent to those of known tire compounds that do not contain such recycled components. Summary of the Invention

[0036] All the foregoing objectives (whether considered individually or in any combination thereof), and other objectives as will become apparent from the following description, are achieved according to the invention by the method for obtaining powder according to claim 1, the rubber-based powder according to claim 24, and the rubber-based mixture according to claim 30.

[0037] In particular, the present invention relates to a method for obtaining rubber-based powder from a rubber-containing product or article, wherein at least one rubber layer of the product or article is pulverized and disintegrated by spraying at least one high-pressure water jet onto the rubber layer to obtain the powder, wherein: - The water jet is delivered at a pressure of approximately 1500-3500 bar. - The water jet is ejected from the conveying section of the rotating head, which rotates at a speed of approximately 500-3000 revolutions per minute. - The feed speed of the rotating head relative to the surface (or vice versa) of the rubber layer to be crushed and disintegrated is approximately 1-9 cm / s, preferably 5-7 cm / s. - The distance between the water jet delivery point and the surface of the rubber layer to be crushed and disintegrated is approximately 10-35 mm.

[0038] Preferably, the present invention relates to a method for obtaining powder from a rubber-containing product or article, wherein the powder is obtained by pulverizing and disintegrating at least one rubber layer of the product or article by spraying at least one high-pressure water jet onto the rubber layer, wherein: - The water jet is delivered at a pressure of approximately 1800-2800 bar. - The water jet is ejected from the conveying section of the rotating head, which rotates at a speed of approximately 500-1000 revolutions per minute. - The feed speed of the rotating head relative to the surface of the rubber layer to be crushed (or vice versa) is approximately 1-9 cm / s. - The distance between the water jet delivery point and the surface of the rubber layer to be crushed is approximately 10-20 mm.

[0039] Preferably, the rubber-containing product or article is a tire, preferably a scrap tire of any vehicle or size.

[0040] Preferably, the rubber-containing product or article includes at least one of the following: rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber protective pads, or generally any other product or article that contains rubber exclusively or primarily or possibly even less in a rubber-containing manner.

[0041] Preferably, the water jet has a substantially flared shape. Preferably, the feed speed of the rotating head relative to the surface (or vice versa) of the rubber layer to be crushed is approximately 5-7 cm / s. Preferably, the water jet also contains ammonia. Preferably, the water jet is pulsed, preferably activated / deactivated and / or modulated at a frequency of approximately 1000-2000 cycles / minute.

[0042] In particular, the present invention relates to a method for obtaining powder from a tire (preferably from a scrap tire), wherein at least one rubber layer of the tire (preferably a scrap tire) is pulverized and disintegrated by spraying at least one high-pressure water jet onto the rubber layer of the tire to be pulverized and disintegrated, thereby obtaining the powder, and wherein: - The water jet is delivered at a pressure of approximately 1800-2800 bar. - The water jet is ejected from the conveying section of the rotating head, which rotates at a speed of approximately 500-1000 revolutions per minute. - The feed speed of the rotating head relative to the surface of the rubber layer to be crushed (or vice versa) is approximately 1-9 cm / s. - The distance between the water jet delivery point and the surface of the rubber layer to be crushed is approximately 10-20 mm.

[0043] Preferably, the water jet has a substantially flared shape. Preferably, the feed speed of the rotating head relative to the surface of the rubber layer to be crushed (or vice versa) is about 5-7 cm / s.

[0044] In particular, the present invention relates to a method for obtaining powder from a tire (preferably from a scrap tire), wherein at least one rubber layer of the tire (preferably a scrap tire) is pulverized and disintegrated by spraying at least one high-pressure water jet onto the rubber layer of the tire to be pulverized and disintegrated, thereby obtaining the powder, wherein the water jet also contains ammonia.

[0045] In particular, the present invention relates to a method for obtaining powder from a tire (preferably from a scrap tire), wherein the powder is obtained by spraying at least one high-pressure water jet onto the rubber layer of the tire to be crushed and disintegrated, thereby crushing and disintegrating at least one rubber layer of the tire (preferably a scrap tire), wherein the water jet is pulsed and preferably activated / deactivated and / or modulated at a frequency of about 1000-2000 cycles / minute. Attached Figure Description

[0046] The invention will be further illustrated below with reference to the accompanying drawings, by way of a preferred embodiment that is described in a purely illustrative rather than restrictive manner, wherein: Figure 1 shows a microscope image of the powder according to the present invention. Figure 2A shows magnified details related to the first particle in Figure 1, and Figure 2B shows magnified details of the second particle in Figure 1.

[0047] Specific embodiments of the present invention and some preferred embodiments thereof Specifically, as used herein, “rubber” refers to natural rubber and / or synthetic rubber and / or mixtures of natural and synthetic rubber present in conventional tires (including “tubed” and “tubeless” types for passenger cars and trucks, and conventional tires for any vehicle of any size). Suitably, the rubber may be derived from the tire tread and / or sidewall and / or carcass.

[0048] In addition, “rubber” in this article means natural rubber and / or synthetic rubber and / or mixtures of natural rubber and synthetic rubber present in rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber protective pads, or products or articles that generally contain only or primarily or possibly even lesser amounts of rubber.

[0049] Suitably, rubber-containing products / articles treated using the method according to the invention may contain only rubber, or may contain primarily rubber, or may contain very little rubber. For example, the product / article may contain rubber as well as a metal portion coated or incorporated into said rubber.

[0050] Appropriately, the rubber layer is defined on (at least) the surface or outer surface of the product / article.

[0051] dust This invention relates to a rubber-based powder 1, obtained from rubber-containing products or articles, for example by exemplary and non-limiting means of obtaining tires, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber tubing, rubber protective pads, or generally any other product or article that contains rubber solely or primarily or possibly even less in any other way. In particular, powder 1 is obtained by mechanically pulverizing the said rubber-containing product or article.

[0052] This invention relates to a rubber-based powder 1 obtained from tires (preferably from end-of-life tires). Specifically, powder 1 is obtained by mechanically pulverizing the tire (preferably an end-of-life tire). More specifically, powder 1 is obtained by mechanically pulverizing the vulcanized rubber layers constituting the tread and / or sidewall of the tire (preferably an end-of-life tire).

[0053] Powder 1 comprises multiple irregularly shaped particles 2. Advantageously, this allows for increased contact and adhesion surface with other components within the rubber-based compound. Suitably, the particles 2 of powder 1 are not spherical in shape.

[0054] Preferably, the powder 1 comprises fragmented particles 2 having various irregular shapes.

[0055] Preferably, the powder 1 comprises stalked particles 2, and in particular, has multiple stalks (i.e., elongated protrusions or protrusions) on its surface. Suitably, the particles 2 of the powder do not have a smooth surface.

[0056] Preferably, the rubber-based powder 1 comprises particles 2 obtained by high-pressure water jet disintegration. Preferably, the rubber powder is desulfurized.

[0057] Preferably, powder 1 is obtained by disintegrating rubber blocks of rubber-containing products or articles using high-pressure water jets, for example by the following exemplary and non-limiting means: tires, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber protective pads, or generally any other product or article that contains rubber only, primarily, or possibly even less in any other way.

[0058] Preferably, the rubber-based powder 1 includes particles 2 that are not obtained and processed by micronization processes or other equivalent mechanical grinding or polishing treatments.

[0059] Preferably, powder 1 comprises particles with a desulfurization surface area greater than 80%. More preferably, powder 1 comprises particles with a desulfurization surface area greater than 95%. Ideally, powder 1 comprises particles with completely desulfurized surfaces.

[0060] Preferably, the rubber-based powder 1 comprises particles 2 with a size of less than about 1 mm. More preferably, the rubber-based powder 1 comprises particles 2 with a size primarily of about 0.1-0.6 mm.

[0061] Preferably, the rubber-based powder 1 comprises porous and / or sponge-like particles 2.

[0062] Preferably, the rubber-based powder 1 includes soft-touch particles 2.

[0063] Preferably, powder 1 comprises particles 2 with an amorphous structure.

[0064] mixture The present invention also relates to a rubber-based compound for tires, comprising the powder 1—as described above in its essential characteristics and possibly in one or more optional and preferred characteristics—in an amount of about 5-30% of the total weight of the compound.

[0065] Preferably, in one possible embodiment, the rubber-based compound for tires contains the powder 1, the content of which is about 10-20% of the total weight of the compound.

[0066] Suitable of the use, rubber-based tire compounds also include components / ingredients used in the production of conventional tires. In particular, rubber-based compounds for tires include natural rubber, synthetic elastomers (e.g., SBR or BR), reinforcing agents (e.g., carbon black and / or silica), vulcanizing agents (e.g., sulfur), and other additives or minor components (e.g., stabilizers, antioxidants, plasticizers, and other components that may be added to improve specific tire performance).

[0067] Preferably, within the rubber-based mixture, powder 1 is mixed together with other components / ingredients.

[0068] The rubber-based compound according to the invention is particularly advantageous because it has mechanical properties—for example, in terms of hardness, elasticity (“resilience”), tear resistance, density, abrasion resistance, tensile strength, elongation at break, 100% modulus, and 300% modulus—that substantially correspond to a rubber-based compound without the powder, which is advantageously obtained from the recycling of end-of-life tires, thus allowing for both disposal and reuse.

[0069] The present invention also relates to a method for reusing tires (preferably end-of-life tires), characterized in that rubber-based powder 1 obtained from the pulverization of the tires is used in the rubber-based mixture for the production of another tire, and characterized in that the amount of powder 1 is about 5-30% of the total weight of the mixture.

[0070] Methods for obtaining powder The present invention also relates to a method for obtaining rubber-based powder 1 from rubber-containing products or articles, for example by means of the following exemplary and non-limiting means: tires, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber tubes, rubber protective pads, or any other product or article that generally at least externally contains (solely or primarily or possibly even lesser) rubber.

[0071] The present invention also relates to a method for obtaining rubber-based powder 1 from tires (preferably from scrap tires).

[0072] Specifically, powder 1 is obtained by pulverizing rubber from a rubber-containing product or article using a high-pressure water jet. More specifically, the method involves spraying at least one high-pressure water jet onto the rubber layer of the rubber-containing product or article to be pulverized / disintegrated.

[0073] Specifically, powder 1 is obtained by crushing the vulcanized rubber of the tire tread and / or sidewall of the tire (preferably a scrap tire) using a high-pressure water jet. More specifically, the method involves spraying at least one jet of high-pressure water onto the rubber layer of the tire (preferably a scrap tire) to be crushed / disintegrated.

[0074] Advantageously, this makes it possible to obtain reusable powder 1, while allowing the disposal of end-of-life tires and / or other rubber products or articles.

[0075] Advantageously, the high-pressure jet allows the rubber layer to be crushed / disintegrated / removed from the steel belts of the tire (and also cleans the belts or other products / manufactured articles with similar construction and composition) to obtain particles 2 of powder 1, and also causes the desulfurization of the particles 2.

[0076] Advantageously, the particles 2 of the powder 1 obtained by the method according to the invention have at least partially desulfurized surfaces, preferably mostly desulfurized, and more preferably completely desulfurized.

[0077] Advantageously, high-pressure water jets also clean the belt layers of tires or other products / articles with similar construction and composition, especially because they penetrate into the spaces between the belt layers.

[0078] The water jet is delivered at a pressure of approximately 1500-3500 bar (preferably 1800-2800 bar).

[0079] The water jet is ejected from the delivery section of the rotating head, and preferably, it rotates about the ejection axis of the high-pressure water jet.

[0080] Preferably, the rotational speed of the self-rotating head is between 500 revolutions per minute (hereinafter referred to as rpm) and 3000 rpm, for example, about 800 rpm. More preferably, the rotational speed of the self-rotating head is between 500 revolutions per minute (hereinafter referred to as rpm) and 1000 rpm, for example, about 800 rpm.

[0081] Preferably, the feed speed of the rotating head relative to the surface of the rubber layer to be crushed (or vice versa) is about 1-9 cm / s, more preferably about 5-7 cm / s.

[0082] Preferably, the distance between the water jet delivery point and the surface of the rubber layer to be crushed is approximately 10-35 mm. More preferably, the distance between the water jet delivery point and the surface of the rubber layer to be crushed is approximately 10-20 mm.

[0083] Ideally, the volume of the rubber layer of powder 1 containing desulfurized particles 2, obtained by crushing / disintegrating, is determined based on the following parameters: - Water jet delivery pressure, - The rotational speed of the rotating head with the water jet delivery section. - The feed speed of the rotary head, and - The distance between the conveying point / section and the surface to be crushed / disintegrated.

[0084] Preferably, the flow rate of the water jet ejected from the conveying section is 3-60 liters / minute, more preferably 5-32 liters / minute.

[0085] Suitablely, the conveying section includes at least one nozzle.

[0086] Suitablely, the water jet / flow has a substantially flared shape (conical or truncated cone). Suitablely, the water jet / flow has a substantially triangular and / or fan-shaped shape. Suitablely, the water jet / flow is substantially aligned with the normal N of the outermost surface of the rubber part to be processed.

[0087] Preferably, the flared water jet has an opening angle of approximately 20-30°.

[0088] Advantageously, in this way, the water jet produces a filing effect similar to that of a rotating digging tip.

[0089] Suitablely, in this way, the water jet excavates a cavity in the rubber part and at / below the impact area in a basically flared pit shape (i.e., basically conical / pyramidal or truncated cone / truncated pyramidal).

[0090] Essentially, when a water jet, applied according to the method of the invention, is sprayed from the conveying section and impacts the area of ​​the rubber portion of the product or article, it removes (preferably disintegrates) a sheet of rubber that is substantially conical / pyramidal (or truncated cone / truncated pyramidal) in shape from that area, thereby forming a depression that is substantially flared in shape on the rubber portion of the same product or article.

[0091] Preferably, the aforementioned vulcanized rubber layer to be removed / crushed / disintegrated may contain a mixture of about 3-50% natural rubber.

[0092] According to one possible implementation, the aforementioned vulcanized rubber layer to be removed / crushed / disintegrated from the tire may contain a mixture of about 10-40% natural rubber.

[0093] According to one possible implementation, the high-pressure water jet may contain ammonia, for example, about 20-30% by weight of ammonia per 100 liters of water. Advantageously, this accelerates desulfurization.

[0094] According to one possible implementation, the high-pressure water jet can be pulsed. More preferably, the water jet can be activated / deactivated (i.e., turned on / off) and / or modulated at a frequency of approximately 1000-2000 cycles / minute. Advantageously, this increases the yield because powder can be obtained more quickly and with a more filamentous structure.

[0095] Preferably, there is no preliminary cleaning stage for the rubber layer of the product or article to be crushed and disintegrated before the removal / crushing / disintegration stage using high-pressure water jets, and in particular, no scraping stage.

[0096] Preferably, the method according to the invention may include a drying stage, a dehydration stage, and a sieving stage for the obtained powder.

[0097] Preferably, in the method according to the invention, water is removed from the obtained powder. Suitablely, water is removed from the obtained powder by filtration and / or by mechanical compression and / or by drying.

[0098] Preferably, in the method according to the invention, the water thus removed from the powder is reused, more preferably used to supply the water jet.

[0099] Preferably, the method according to the present invention may include: - The stage of filtering the obtained powder using at least one filter element (e.g., a filter bag). - The stage of mechanically compressing the filtered powder. - The stage of drying the compressed powder.

[0100] Preferably, in the method according to the invention, the stage of pulverizing and disintegrating at least one rubber layer of the product or article by spraying at least one jet of high-pressure water can be carried out inside a container, preferably inside a transportable or self-propelled container. Ideally, the stage of removing water (preferably by filtration) from the obtained powder is carried out inside the container.

[0101] In one possible implementation, wet, downward-falling powder 1 is obtained by spraying at least one high-pressure water jet onto the rubber layer, causing the layer to pulverize / disintegrate. Preferably, the wet powder 1 thus obtained falls into a storage tank below, where it is collected and pumped to a first filter (more preferably a filter bag) to remove approximately 80-90% by weight of water.

[0102] Suitablely, the water thus removed (with a purity of about 90-95%) can be reused to supply high-pressure water jets. Preferably, the water removed from the powder is further filtered (e.g., through one or more filters of up to about 1 micrometer) before reuse—particularly before being reintroduced into the high-pressure water jet supply tank.

[0103] Ideally, the filtered powder has a moisture content of about 10-20% and can be collected in a filter bag. Preferably, the filtered powder is then mechanically compressed (e.g., passed between two rollers) to remove a greater amount of water (e.g., up to about 5-10% by weight). Preferably, after mechanical compression, the powder is dried to remove an even greater amount of water (e.g., down to less than 2% by weight).

[0104] Preferably, the powder is treated to achieve a humidity of about 1-20% (more preferably less than 2%).

[0105] Suitably, in one possible embodiment, the equipment for jetting high-pressure water onto the rubber layer to be crushed and disintegrated in the rubber product or article, and the filtration system for the resulting wet powder, are both housed in the same container, which may be transportable or self-propelled. Preferably, in one possible embodiment, a mechanical compaction module and / or a drying module may also be housed in the same container.

[0106] Advantageously, the method according to the invention allows the production of about 150 kg of powder with an energy consumption of about 30-30 KW.

[0107] Advantageously, the method according to the invention allows for the removal and pulverization of all rubber (including the tread and sidewall, up to the belt layer) of a truck tire (TIR) ​​within approximately 15-20 minutes, thereby obtaining powder 1 according to the invention.

[0108] The present invention relates to a method for reusing tires (preferably end-of-life tires), characterized by using rubber-based powder obtained from the crushing / disintegration treatment of tires (especially end-of-life tires) (preferably by high-pressure water (i.e., so-called "water jet")).

[0109] Advantageously, the rubber-based powder obtained by the method according to the invention is essentially ready for use, and in particular, no other mechanical processing steps, such as grinding or micronization, are required.

[0110] Therefore, the rubber-based powder obtained by the method according to the invention is "ready to use".

[0111] Suitablely, the rubber-based powder obtained by the method according to the invention has neutral, non-toxic and non-biological chemical and physical properties.

[0112] Suitably, the rubber-based powder obtained by the method according to the invention contains sulfur and carbon.

[0113] Suitablely, the rubber-based powder obtained by the method according to the invention retains its characteristics (low degradability) over time while remaining biodegradable (desulfurized).

[0114] Suitablely, the rubber-based powder obtained by the method according to the invention has high hygroscopicity, porosity, and softness.

[0115] Preferably, the rubber-based powder obtained by the method according to the present invention comprises a plurality of irregularly shaped particles 2 with a desulfurization surface area greater than 80%, more preferably greater than 95%.

[0116] Preferably, the rubber-based powder obtained by the method according to the invention comprises stalked particles 2.

[0117] Preferably, the rubber-based powder obtained by the method according to the invention comprises particles 2 with a size mainly of about 0.1-0.6 mm.

[0118] Preferably, the rubber-based powder obtained by the method according to the invention comprises porous / sponge-like and soft-touch particles 2.

[0119] Advantageously, the present invention relates to a rubber-based compound for tires, wherein the compound comprises the rubber-based powder obtained by the method according to the invention, the powder comprising about 5-30% of the total weight of the compound. Preferably, in the compound, the rubber-based powder obtained by the method according to the invention is mixed with other components of the compound, wherein the other components include natural rubber, synthetic elastomers, and reinforcing agents (e.g., carbon black).

[0120] The present invention also relates to the use of rubber-based powder, which is obtained by high-pressure water jet treatment of rubber-containing products or articles, for various applications.

[0121] The present invention also relates to the use of rubber-based powder, which is obtained by treating tires (especially end-of-life tires) with high-pressure water jet, for various applications.

[0122] The invention has been described and illustrated in some preferred embodiments, but it should be understood that variations may be made thereto without departing from the scope of protection of this patent for industrial purposes.

Claims

1. A method for obtaining a rubber-based powder (1) from a rubber-containing product or article, wherein at least one rubber layer of the rubber-containing product or article is fragmented and disintegrated by means of at least one jet of high-pressure water sprayed onto the rubber layer, to obtain the powder, characterized in that: - the water jet is delivered at a pressure of about 1500-3500 bar, - the water jet is sprayed from a delivery portion of a rotating head that is self-rotating at a rotation speed of about 500-3000 revolutions / minute, - the feed speed of the rotating head relative to the surface of the rubber layer to be fragmented and disintegrated, or vice versa, is about 1-9 cm / sec, preferably 5-7 cm / sec, - the distance between the delivery point of the water jet and the surface of the rubber layer to be fragmented and disintegrated is about 10-35 mm.

2. The method according to claim 1, wherein: - the water jet is delivered at a pressure of about 1800-2800 bar, - the water jet is sprayed from a delivery portion of a rotating head that is self-rotating at a rotation speed of about 500-1000 revolutions / minute, - the feed speed of the rotating head relative to the surface of the rubber layer to be fragmented and disintegrated, or vice versa, is about 1-9 cm / sec, preferably 5-7 cm / sec, - the distance between the delivery point of the water jet and the surface of the rubber layer to be fragmented and disintegrated is about 10-20 mm.

3. The method according to claim 1 or 2, wherein the rubber-containing product or article is a tyre, preferably a scrap tyre of any vehicle or size.

4. The method according to claim 1 or 2, wherein the rubber-containing product or article comprises at least one of the following: a rubber conveyor belt, a rubber belt, a rubber track, a rubber carpet, a rubber floor, a rubber tube, a rubber protective mat.

5. The method according to one or more of the preceding claims, wherein the water jet has a substantially flared shape.

6. The method according to one or more of the preceding claims, wherein the water jet has a substantially triangular and / or sectorial configuration.

7. The method according to one or more of the preceding claims, wherein the powder thus obtained comprises particles (2) having at least partially, preferably mostly, desulfurized surfaces.

8. The method according to one or more of the preceding claims, wherein the water jet also contains ammonia.

9. The method according to one or more of the preceding claims, wherein the water jet is pulsed, preferably activated / deactivated and / or modulated at a frequency of about 1000-2000 cycles / minute.

10. The method according to one or more of the preceding claims, wherein the rubber to be fragmented and disintegrated comprises a mixture having about 3-50% natural rubber.

11. The method according to one or more of the preceding claims, wherein the rubber-containing product or article is a tyre, and wherein the rubber layer of the tyre to be fragmented and disintegrated comprises a mixture having about 10-40% natural rubber.

12. The method according to one or more of the preceding claims, wherein there is no phase of cleaning and scraping of the rubber layer to be pulverized and disintegrated before the pulverization and disintegration of at least one rubber layer by means of the spraying of at least one jet of high-pressure water.

13. The method according to one or more of the preceding claims, wherein it comprises a drying step, a dehydration step and a sieving step of the powder obtained.

14. The method according to one or more of the preceding claims, wherein the water is removed from the powder obtained.

15. The method according to the preceding claim, wherein the water removed from the powder is reused, preferably to feed the water jets.

16. The method according to one or more of the preceding claims, wherein the water is removed from the powder by filtration.

17. The method according to one or more of the preceding claims, wherein the water is removed from the powder by mechanical compression.

18. The method according to one or more of the preceding claims, wherein the water is removed from the powder by drying.

19. The method according to one or more of the preceding claims, wherein it further comprises, in sequence: - a phase of filtration of the powder obtained by means of at least one filtering element, preferably a filter bag, - a phase of mechanical compression of the filtered powder, - a phase of drying of the compressed powder.

20. The method according to one or more of the preceding claims, characterized in that, The phase of pulverization and disintegration of at least one rubber layer by means of the spraying of at least one jet of high-pressure water is carried out inside a container, preferably a transportable or self-propelled container.

21. The method according to the preceding claim, wherein the step of removal of water from the powder obtained is carried out inside the container, preferably by filtration.

22. The method according to one or more of the preceding claims, characterized in that, The flow rate of the water jets sprayed from the delivery portion is comprised between 3 and 60 liters per minute, preferably between 5 and 32 liters per minute.

23. The method according to one or more of the preceding claims, characterized in that, The water is removed from the powder to reach a percentage of humidity of about 1-20%, preferably less than 2%.

24. A rubber-based powder (1) obtained by mechanical shredding of a rubber- containing product or article, preferably a tyre, a rubber conveyor belt, a rubber belt, a rubber track, a rubber carpet, a rubber floor, a rubber tube, a rubber mat or generally any other rubber-containing product or article, characterized in that, It comprises a plurality of irregularly shaped particles (2) having a desulfurized surface greater than 80%, more preferably greater than 95%.

25. The powder according to the preceding claim, characterized in that, The particles (2) are shank-shaped.

26. Powder according to one or more of the preceding claims, characterized in that The particles (2) are obtained by disintegrating a tire rubber, preferably a scrap tire rubber, with a high-pressure water jet.

27. Powder according to one or more of the preceding claims, characterized in that The particles (2) are obtained by disintegrating the rubber of a rubber conveyor belt, a rubber belt, a rubber track, a rubber carpet, a rubber floor, a rubber tube, a rubber protection mat or generally any other product or article containing rubber.

28. Powder according to one or more of the preceding claims, characterized in that The particles (2) have a size mainly comprised between about 0.1 and 0.6 mm.

29. Powder according to one or more of the preceding claims, characterized in that The particles (2) are porous / spongy and soft to the touch.

30. A rubber-based mix for tyres, characterised in that, It comprises the powder (1) according to one or more of the preceding claims in a quantity comprised between about 5 and 30% of the total weight of the mix.

31. The mixture according to the preceding claim, characterized in that The powder (1) is mixed with the other ingredients of the mix and wherein the other ingredients comprise natural rubber, synthetic elastomers, reinforcing agents such as carbon black.

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