WO2025022253A1

WO2025022253A1 - Method for obtaining a rubber-based powder

Info

Publication number: WO2025022253A1
Application number: PCT/IB2024/056971
Authority: WO
Inventors: Gennaro SCARFIGLIERI; Enrico FIORE
Original assignee: Scarfiglieri Gennaro; Fiore Enrico
Priority date: 2023-07-26
Filing date: 2024-07-18
Publication date: 2025-01-30

Abstract

Method for obtaining a rubber-based powder (1) starting from products or articles containing rubber, wherein to obtain said powder, at least one layer of rubber, of a product or article containing rubber, is crushed and disintegrated by sending at least one high pressure water jet against said rubber layer, said method is characterized by the fact that: - said water jet is delivered at a pressure of approximately 1500 - 3500 bar, - said jet of water comes out from a delivery section of a rotating head which rotates on itself at a rotation speed of approximately 500 - 3000 revolutions per minute, - the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed and disintegrated, or vice versa, is approximately 1 - 9, preferably 5 - 7 cm/second, - the distance between the delivery point of the water jet and the surface of the rubber layer to be crushed and disintegrated is approximately 10 - 35 mm.

Description

METHOD FOR OBTAINING A RUBBER-BASED POWDER

TECHNICAL FIELD

The present invention relates to a method for obtaining rubber-based powder from products or articles containing rubber.

The present invention also relates to a method for obtaining rubber-based powder from tyres, preferably from end-of-life tyres.

The present invention also relates to a method for obtaining rubber-based powder from rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders or, in general, from products or articles containing - exclusively or mainly or even to a lesser extent - rubber.

The present invention relates to a rubber-based powder which is obtained by said method.

The present invention relates to a rubber-based powder which is obtained from the mechanical crushing of products or articles containing rubber, preferably tyres, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders or in general any other product or product containing - exclusively or mainly or even to a lesser extent - rubber.

The present invention concerns a rubber-based powder which is obtained from tyres, preferably from end-of-life tyres. In particular, the present invention relates to a rubber-based powder which is obtained from the crushing treatment of tyres, preferably end-of-life tyres.

The present invention also concerns a rubber-based compound for tyres. STATE OF THE TECHNIQUE

The problem of disposing of end-of-life tires (ELTs) is an issue of global importance in the context of environmental sustainability and waste recycling. The technologies most in use today for the recovery of end-of-life tires are in fact extremely energy-intensive and therefore harmful to the environment. Furthermore, the material or rather the material obtained from the demolition of end-of-life tires does not ennoble the precious rubber.

According to art.228 of DL152/2006, in Italy as in other EU countries, producers and importers are responsible for managing end-of-life tires in quantities equal to those placed on the market by them.

From Ecopneus data relating to the Italian territory, the number of end-of-life tires collected in the year 2020 is equal to 350,538 tonnes, corresponding to 91 % of the legal target. Currently, the methods for recovering end-of-life tires are divided into two categories:

- energy recovery is based on the calorific value of rubber, which makes it an excellent fuel like coal. The main use made of it is combustion in the cement factory, followed by waste-to-energy and pyrolysis.

- material recovery is instead focused on the crushing of tires in order to obtain a granulate of various sizes that can be reused in various industrial sectors, first and foremost the sports one; among the techniques used, the most widespread in Italy is granulation at room temperature, followed by devulcanization (chemical, physical or biological), water-jet cutting, electrothermal process and cryogenic granulation.

T aking into consideration the material recovery and the materials obtained from the various aforementioned processes, it is highlighted how the metal and/or fibers which represent only 5% by weight of the waste, easily find a place in the material-on- material recycling processes (iron goes to the foundry and the fibers are reused in the production of any synthetic material), while the reuse of the rubber material remains complex.

In material recovery, although some of the techniques indicated above are able to separate the materials that make up tires (rubber, metal and/or fibres), there are still no large-scale processes and products that use secondary raw materials, giving rise to a economically and environmentally sustainable market. All currently known products and processes sustain themselves with difficulty and only thanks to the tax on end-of- life tyres.

For this reason, in the management of end-of-life tires in Italy it can be noted that, even today, the majority of these are destined for energy recovery, to be precise, 59% of the total; we must then consider the quantity that is recovered in Italy and that exported to foreign cement factories which stands at 43%. A simple calculation shows that end-of-life tires destined for energy reuse are 111 ,845 tons and, of these, 48,093 are destined for foreign markets.

Furthermore, considering the well-known damage that tire burning causes on human health and the environment, one can easily understand how far we still are from an adequate valorisation of the rubber derived from end-of-life tyres.

In this context, the use of a high-pressure water jet to crumble the vulcanized rubber layer of a tire and thus obtain, following an expensive micronization operation, granules with a substantially spherical or in any case a substantially spherical shape is already known, regular. The use of the granules thus obtained in the production of the rubber compound used for tires is also already known. In particular, currently, these granules are used as an alternative to carbon black, and the quantity of these granules used is usually equal to approximately 3% - 5% of the quantity of carbon black that is normally used in the same compound.

Furthermore, the known type of rubber granules used in the production of the rubber compound for tires are not satisfactory as they do not adhere properly and stably to the inside of the rubber compound.

For example, obtaining rubber granules from mechanical tire crushing is described in “Multiresponse optimization of process parameters in water jet pulverization via response surface methodology” by Wang Zefeng et al, and also in “Sustainable rubber recycling from waste tires by waterjet: a novel mechanistic and practical analysis ” by Bowles AJ et al.

OBJECTS OF THE INVENTION

The aim of the invention is to propose a method for obtaining a rubber-based powder, starting from products or articles containing rubber, which allows to overcome, at least in part, the aforementioned drawbacks present in traditional solutions.

Another aim of the invention is to propose a method for obtaining a rubberbased powder which can be implemented in a simple, rapid and low-cost manner.

Another aim of the invention is to propose a method for obtaining a rubberbased powder which is an alternative and improvement compared to traditional solutions.

Another aim of the invention is to propose a method for obtaining a rubberbased powder which is highly environmentally friendly.

Another aim of the invention is to propose a method for obtaining a rubberbased powder from tyres, preferably from end-of-life tyres, which allows the aforementioned drawbacks present in traditional solutions to be overcome, at least in part.

Another aim of the invention is to propose a method for obtaining a rubberbased powder from tires which can be implemented in a simple, rapid and low-cost manner.

Another aim of the invention is to propose a method for obtaining a rubberbased powder from tires which is an alternative and improvement compared to traditional solutions.

Another aim of the invention is to propose a method for obtaining a rubberbased powder from tires which is highly environmentally friendly. Another aim of the invention is to propose a rubber-based powder, which is obtained from products or articles containing rubber, which allows the aforementioned drawbacks present in traditional solutions to be overcome at least in part.

Another aim of the invention is to propose a rubber-based powder which is obtained from tyres, preferably from end-of-life tyres, which allows the aforementioned drawbacks present in traditional solutions to be overcome, at least in part.

Another aim of the invention is to propose a powder that attaches stably to the inside of the rubber compound.

Another aim of the invention is to propose a powder which is alternative and improved compared to known solutions.

Another aim of the invention is to propose a powder that can be obtained from tyres, preferably from end-of-life tyres, in a simple, rapid and low-cost way.

Another aim of the invention is to propose a tire compound that is highly environmentally friendly.

Another aim of the invention is to propose a tire compound which, although including recovery components obtained from the treatment of end-of-life tyres, has structural and functional characteristics substantially comparable to known tire compounds which are devoid of such recovery components.

SUMMARY OF THE INVENTION

All the aims as above-mentioned here, considered both individually and in any combination thereof, and others that will emerge from the following description are achieved, according to the invention, with a method for obtaining powder according to claim 1 , with a powder at rubber base according to claim 24, with a rubber-based compound according to claim 30.

In particular, the present invention relates to a method for obtaining a rubberbased powder starting from products or articles containing rubber, wherein to obtain said powder at least one rubber layer of a product or article containing rubber is crushed and disintegrated, by sending at least one high pressure water jet against said rubber layer, and wherein :

- said waterjet is delivered at a pressure of approximately 1500 - 3500 bar,

- said jet of water comes out from a delivery section of a rotating head which rotates on itself at a rotation speed of approximately 500 - 3000 revolutions per minute,

- the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed and disintegrated (or vice versa) is approximately 1 - 9, preferably 5 - 7 cm/second, - the distance between the point of delivery of the water jet and the surface of the rubber layer to be crushed and disintegrated is approximately 10 - 35 mm.

Preferably, the present invention relates to a method for obtaining powder from products or articles containing rubber, wherein to obtain said powder, at least one layer of rubber, of a product or article containing rubber, is crushed and disintegrated by sending at least one high pressure water jet against said rubber layer, and wherein:

- said waterjet is delivered at a pressure of approximately 1800 - 2800 bar,

- said jet of water comes out from a delivery section of a rotating head which rotates on itself at a rotation speed of approximately 500 - 1000 revolutions per minute,

- the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed (or vice versa) is approximately 1 - 9,

- the distance between the point of delivery of the water jet and the surface of the rubber layer to be crushed is approximately 10 - 20 mm.

Preferably, said product or article containing rubber is a tyre, preferably an end- of-life tire of any vehicle or size.

Preferably, said product or article containing rubber includes at least one of rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders, or in general any other product or article containing - exclusively or mainly or possibly also to a lesser extent - rubber.

Preferably, said water jet has a substantially flared shape. Preferably, the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed (or vice versa) is approximately 5 - 7 cm/second. Preferably, said water jet also contains ammonia. Preferably, said water jet is impulsive, preferably it is activated/deactivated and/or modulated at a frequency of approximately 1000 - 2000 cycles per minute.

In particular, the present invention relates to a method for obtaining powder from tyres, preferably from end-of-life tyres, wherein at least one rubber layer of a tyre, preferably of an end-of-life tyre, is crushed and disintegrated, thus obtaining said powder, by sending at least one jet of high pressure water against said layer of rubber to be crushed and disintegrated of said tyre, and wherein:

- said waterjet is delivered at a pressure of approximately 1800 - 2800 bar,

- the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed (or vice versa) is approximately 1 - 9, - the distance between the point of delivery of the water jet and the surface of the rubber layer to be crushed is approximately 10 - 20 mm.

Preferably, said water jet has a substantially flared shape. Preferably, the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed (or vice versa) is approximately 5 - 7 cm/second.

In particular, the present invention relates to a method for obtaining powder from tyres, preferably from end-of-life tyres, wherein at least one rubber layer of a tyre, preferably of an end-of-life tyre, is crushed and disintegrated, thus obtaining said powder, by sending at least one high pressure waterjet against said rubber layer to be crushed and disintegrated of said tire, and wherein said water jet also contains ammonia.

In particular, the present invention relates to a method for obtaining powder from tyres, preferably from end-of-life tyres, wherein at least one rubber layer of a tyre, preferably of an end-of-life tyre, is crushed and disintegrated, thus obtaining said powder, by sending at least one high pressure waterjet against said rubber layer to be crushed and disintegrated of said tire, and wherein said water jet is impulsive, preferably activated/deactivated and/or modulated at a frequency of approximately 1000 - 2000 cycles per minute.

DESCRIPTION OF THE FIGURES

The present invention is further clarified below in some of its preferred practical embodiments reported for purely illustrative and non-limiting purposes with reference to the attached drawings, wherein: figure 1 shows a microscope image of the powder according to the invention, figure 2A shows an enlarged detail relating to a first granule in fig. 1 , and figure 2B shows an enlarged detail of a second granule in fig. 1.

DETAILED DESCRIPTION OF THE INVENTION AND SOME OF ITS PREFERRED FORMS OF EMBODIMENT

In particular, here "rubber" means natural and/or synthetic rubber and/or the mixture based on natural and synthetic rubber present in traditional tyres, both of the "tube type " and "tubeless" typologies, both for cars and for trucks, and in general in the traditional tires of any vehicle of any size. Conveniently, the rubber may be from the tread and/or sidewalls and/or casing of the tires.

Furthermore, here "rubber" means natural and/or synthetic rubber and/or the mixture based on natural and synthetic rubber present in rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders or, in general, from products or products containing - exclusively or predominantly or possibly also to a lesser extent - rubber.

Conveniently, the product/article containing rubber treated with the method according to the invention can contain exclusively rubber, or it can contain mainly rubber, or it can contain rubber in a minimal part. For example, the product/manufactured product may contain rubber and also metal parts which are coated or incorporated into said rubber.

Suitably, the rubber layer is defined (at least) superficially or externally on said product/article.

DUST

The present invention relates to a rubber-based powder 1 which is obtained from products or articles containing rubber, such as by way of example and without limitation: tyres, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring rubber, rubber pipes, rubber fenders or in general any other product or product containing - exclusively or mainly or possibly also to a lesser extent - rubber. In particular, the powder 1 is obtained from the mechanical crushing treatment of said products or articles containing rubber.

The present invention relates to a rubber-based powder 1 which is obtained from tyres, preferably from end-of-life tyres. In particular, powder 1 is obtained from the mechanical crushing treatment of tyres, preferably end-of-life tyres. More in detail, the powder 1 is obtained from the mechanical crushing treatment of the layer of vulcanized rubber which constitutes the tread of a tire and/or the sidewall of a tyre, preferably out of use.

The powder 1 comprises a plurality of granules 2 of irregular shape. Advantageously, this allows to increase the contact and attachment surface with the other components within a rubber-based compound. Conveniently, the granules 2 of the powder 1 do not have a spherical shape.

Preferably, the powder 1 comprises granules 2 fragmented and of various irregular shapes.

Preferably, the powder 1 comprises granules 2 which are pedunculated and, in particular, have a plurality of peduncles (i.e. elongated protuberances or protrusions) on the surface. Conveniently, the granules 2 of the powder do not have a smooth surface.

Preferably, the rubber-based powder 1 comprises granules 2 obtained by disintegration with a high-pressure water jet. Preferably, said rubber powder is devulcanised. Preferably, the powder 1 is obtained from the disintegration, through the use of a high pressure waterjet, of the rubber mass of products or articles containing rubber, such as by way of example and without limitation: tyres, rubber conveyor belts, belts rubber, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders or in general any other product or product containing - exclusively or mainly or possibly also to a lesser extent - rubber.

Preferably, the rubber-based powder 1 comprises granules 2 which are not obtained and treated by means of a micronization process or other equivalent mechanical grinding or abrasion treatments.

Preferably, the powder 1 comprises granules with a devulcanised surface greater than 80%. More preferably, the powder 1 comprises granules with a devulcanized surface greater than 95%. Ideally, powder 1 comprises granules with an entirely devulcanised surface.

Preferably, the rubber-based powder 1 comprises granules 2 having dimensions smaller than approximately 1 mm. More preferably, the rubber-based powder 1 comprises granules 2 having dimensions predominantly of about 0.1 - 0.6 mm.

Preferably, the rubber-based powder 1 comprises granules 2 which are porous and/or spongy.

Preferably, the rubber-based powder 1 comprises granules 2 which are soft to the touch.

Preferably, the powder 1 comprises granules 2 of an amorphous structure. MIX

The present invention also concerns a rubber-based compound for tires containing said powder 1 - as described above in its essential characteristics and possibly in one or more optional and preferential characteristics - in a quantity of approximately 5 - 30% of the total weight of the compound.

Preferably, in a possible embodiment, the rubber-based compound for tires contains said powder 1 in a quantity of approximately 10 - 20% of the total weight of the compound.

Conveniently, the rubber-based tire compound also includes components/ingredients that are intended for the production of a traditional tire. In particular, the rubber-based compound for tires includes natural rubber, synthetic elastomers (such as SBR or BR), reinforcers (such as carbon black and/or silica), vulcanizing agents (for example sulphur) and other additives or secondary ingredients (for example stabilizers, antioxidants, plasticizing oils and other ingredients that can be added to improve specific tire properties).

Preferably, inside the rubber-based compound, the powder 1 is mixed together with the other components/ingredients.

The rubber-based compound according to the invention is particularly advantageous as it has mechanical characteristics - for example in terms of hardness, elasticity ("rebound"), resistance to the propagation of a tear, density, abrasion, tensile strength, elongation breakage, 100% modulus and 300% modulus - which are substantially corresponding to those of the rubber-based compound without said powder which is advantageously obtained from the recovery of end-of-life tyres, thus allowing their disposal and reuse at the same time.

The present invention also concerns a method of reusing tyres, preferably end- of-life tyres, characterized in that the rubber-based powder 1 , obtained from the crushing of said tyres, is used inside a rubber-based compound for producing further tyres, and is characterized in that said powder 1 is used in a quantity of approximately 5 - 30% of the total weight of said compound.

METHOD TO OBTAIN THE POWDER

The present invention also relates to a method for obtaining rubber-based powder 1 starting from products or articles containing rubber, such as by way of example and without limitation: tyres, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders or in general any other product or product containing at least externally - exclusively or predominantly or possibly even to a lesser extent - rubber.

The present invention also concerns a method for obtaining rubber-based powder 1 starting from tyres, preferably from end-of-life tyres.

In particular, powder 1 is obtained from the crushing of rubber from products or articles containing rubber by disintegration with a high pressure water jet. More in detail, the method involves sending at least one jet of high pressure water against the layer of rubber to be crushed/disintegrated of said product or article containing rubber.

In particular, the powder 1 is obtained by crushing the vulcanized rubber of the tread and/or sidewall of a tyre, preferably out of use, by disintegration with a high pressure water jet. More in detail, the method provides the sending of at least one jet of high-pressure water against the layer of rubber to be crushed/disintegrated of a tyre, preferably of an end-of-life tyre. Advantageously, this allows to obtain the powder 1 which can be reused and at the same time allows the disposal of end-of-life tires and/or other rubber products or articles.

Advantageously, the high pressure jet allows the rubber layer to be crushed/disintegrated/removed from the steel belts of the tires (also cleaning said plies) or other products/manufactured articles with a similar configuration and composition, thus obtaining the granules 2 of powder 1 , and also causes the devulcanization of said granules 2.

Advantageously, the granules 2 of the powder 1 obtained with the method according to the invention have a surface which is at least partly devulcanised, preferably mostly devulcanised, more preferably entirely devulcanised .

Advantageously, the high pressure water jet also cleans the belts of tires or other products/articles with a similar configuration and composition, in particular because it penetrates the spaces between said belts.

The water jet is delivered at a pressure of approximately 1500 - 3500 bar, preferably 1800 - 2800 bar.

The water jet comes out from a delivery section of a head which rotates on itself and, preferably, rotates around the exit axis of the high pressure water jet.

Preferably, the rotation speed of said self-rotating head is preferably between 500 revolutions per minute (hereinafter rpm) and 3000 rpm, for example approximately 800 rpm. More preferably, the rotation speed of said self-rotating head is preferably between 500 revolutions per minute (hereinafter rpm) and 1000 rpm, for example approximately 800 rpm.

Preferably, the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed (or vice versa) is about 1 - 9 cm/second, more preferably about 5 - 7 cm/second.

Preferably, the distance between the point of delivery of the water jet 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.

Ideally, the volume of the rubber layer that is crushed/disintegrated, thus obtaining the powder 1 with devulcanized granules 2, is defined on the basis of the following parameters:

- water jet delivery pressure,

- rotation speed of the rotating head equipped with the water jet delivery section,

- advancement speed of said rotating head, and - distance between the delivery point/section and the surface to be crushed/disintegrated.

Preferably, the flow rate of said water jet coming out of the delivery section is 3 - 60 liters per minute, preferably it is 5 - 32 liters per minute.

Conveniently, the delivery section includes at least one nozzle.

Conveniently, the jet/flow of water has a substantially flared shape (conical or truncated cone). Conveniently, the jet/flow of water has a substantially triangular and/or fan shape. Conveniently, the jet/flow of water is substantially aligned with the normal N to the outermost surface of the portion of rubber to be machined.

Preferably, the opening angle of the substantially flared water jet is approximately 20 - 30°.

Advantageously, in this way, the water jet causes a rasping effect similar to that of a rotating digging tip.

Conveniently, in this way, the water jet excavates, in the rubber portion and in correspondence with/below the impact zone, a hollow substantially shaped like a flared crater (i.e. substantially conical/pyramidal or truncated cone/truncated pyramid).

In essence, when the water jet, which is applied with the method according to the invention and which comes out from the delivery section, impacts on the area of the rubber portion of the product or article, it removes from the latter (preferably disintegrates) a slice of rubber with a substantially conical/pyramidal shape (or truncated cone/truncated pyramid), thus forming a substantially flared crater-shaped recess on the rubber portion of the same product or article.

Preferably, the aforementioned layer of vulcanized rubber to be removed/crushed/disintegrated can comprise a mixture with approximately 3 - 50% natural rubber.

In accordance with a possible embodiment, the aforementioned layer of vulcanized rubber to be removed/crushed/disintegrated from the tire can comprise a mixture with approximately 10 - 40% natural rubber.

According to one possible embodiment, the high pressure waterjet may contain ammonia, for example it may contain approximately 20 - 30% by weight of ammonia per 100 liters of water. Advantageously, this allows speeding up the devulcanization .

According to one possible embodiment, the high pressure water jet may be impulsive. More preferably, the water jet can be activated/deactivated (i.e. open/closed) and/or modulated with a frequency of approximately 1000 - 2000 cycles per minute. Advantageously, this increases the yield as it allows the powder to be obtained more quickly, as well as it allows the powder to be obtained more filamented. Preferably, before said removal/crushing/disintegration phase using a high pressure waterjet, no preliminary cleaning phase of the rubber layer to be crushed and disintegrated of said product or article is provided, and above all no scratching phase is provided.

Preferably, the method according to the invention can comprise a drying phase, an exsiccation phase and a screening phase of the powder obtained.

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

Preferably, in the method according to the invention, the water thus removed from said powder is reused, more preferably it is reused to feed said waterjet.

Preferably, the method according to the invention can comprise:

- a filtration phase of the powder obtained through the use of at least one filtering element (for example a filter bag),

- a mechanical compression phase of the filtered powder,

- a drying phase of the compressed powder.

Preferably, in the method according to the invention, said phase wherein at least one rubber layer of a product or article is crushed and disintegrated by sending at least one jet of high pressure water can be implemented inside a container, preferably of a container that can be transportable or self-propelled. Ideally, said phase wherein the water is removed from the obtained powder, preferably by filtration, is carried out inside said container.

In a possible embodiment, by sending at least one jet of high-pressure water against said rubber layer, the crushing/disintegration of said layer is caused, thus obtaining a powder 1 which is wet and which falls downwards. Preferably, the wet powder 1 so obtained falls into an underlying tank where it is collected and, via a pump, is pushed towards a first filter (more preferably a filter bag) to thus remove approximately 80 - 90% by weight of water.

Conveniently, the water so removed (which can have a purity of approximately 90-95%) can be reused to feed the high pressure water jet. Preferably, before being reused and - in particular - before being reintroduced into the high pressure water jet supply tank, the water that has been removed from the powder is further filtered (for example by passing through one or more filters up to approximately 1 micrometer).

Ideally, the filtered powder has a humidity of around 10 - 20% and can be collected in the filter bag. Preferably, the filtered powder is then subjected to mechanical compression (for example by passing it between two rollers), to thus remove a further quantity of water (for example reaching approximately 5 - 10% by weight). Preferably, following mechanical compression, the powder is subjected to drying, to thus remove a further quantity of water (for example reaching a value lower than 2% by weight).

Preferably, the powder is treated so as to achieve a humidity of approximately 1 - 20%, more preferably less than 2%.

Conveniently, in a possible embodiment, the apparatus for sending a jet of high pressure water against said rubber layer to be crushed and disintegrated of said rubber product or article ,and also the filtration system of the wet powder so obtained are housed inside the same container, which can be transportable or self-propelled. Preferably, in a possible embodiment, the mechanical compaction module and/or the drying module can also be housed inside the same container.

Advantageously, the method according to the invention allows the production of approximately 150 kg of powder with an energy expenditure of approximately 30 - 30 KW.

Advantageously, the method according to the invention allows to remove and crush all the rubber (both of the tread and of the sidewalls, reaching up to the belts) of a truck tire (TIR), thus obtaining the powder 1 according to the invention, in a time of approximately 15 - 20 minutes.

The present invention relates to a method of reusing tyres, preferably end-of- life tyres, characterized by the fact that it is used the rubber-based powder obtained from the crushing/disintegration treatment of tyres, in particular end-of-life tyres, preferably by means of a jet of high pressure water (ie the so-called “waterjet”).

Advantageously, said rubber-based powder obtained with the method according to the invention is substantially ready for use and, in particular, does not require other mechanical processing procedures, such as abrasion or micronization.

Therefore, said rubber-based powder obtained with the method according to the invention is "ready-to-use".

Conveniently, said rubber-based powder obtained with the method according to the invention has a chemical-physical nature which is neutral, non-toxic and free of biological components.

Conveniently, said rubber-based powder obtained with the method according to the invention contains sulfur and carbon.

Conveniently, said rubber-based powder obtained with the method according to the invention maintains its characteristics unchanged over time (low degradation), while remaining biodegradable (being devulcanised). Conveniently, said rubber-based powder obtained with the method according to the invention has a high hygroscopicity, porosity and softness.

Preferably, said rubber-based powder obtained with the method according to the invention comprises a plurality of granules 2 of irregular shape and having a devulcanised surface greater than 80%, more preferably greater than 95%.

Preferably, said rubber-based powder obtained with the method according to the invention comprises granules 2 which are with peduncles.

Preferably, said rubber-based powder obtained with the method according to the invention comprises granules 2 which mainly have dimensions of about 0.1 - 0.6 mm.

Preferably, said rubber-based powder obtained with the method according to the invention comprises granules 2 which are porous/spongy and soft to the touch.

Advantageously, the present invention relates to a rubber-based compound for tyres, wherein said compound comprises said rubber-based powder, which is obtained with the method according to the invention, in a quantity of about 5 - 30% of the total weight of the compound. Preferably, in said compound, the rubber-based powder, which is obtained with the method according to the invention, is mixed with the other ingredients of said compound, and wherein said other ingredients include natural rubber, synthetic elastomers, reinforcers such as example carbon black.

The present invention also relates to the use of rubber-based powder obtained from the treatment of products or articles containing rubber by means of a high- pressure water jet for various uses.

The present invention also concerns the use of rubber-based powder obtained from the treatment of tyres, in particular end-of-life tyres, using a high-pressure water jet for various uses.

The present invention has been illustrated and described in some preferred embodiments, but it is understood that executive variations may be made to them, without however departing from the scope of protection of the present patent for industrial invention.

Claims

C L A I M S

1 . Method for obtaining a rubber-based powder (1 ) starting from products or articles containing rubber, wherein to obtain said powder, at least one rubber layer of a product or article containing rubber, is crushed and disintegrated by sending at least one high pressure water jet against said rubber layer, said method is characterized by the fact that:

- said waterjet is delivered at a pressure of approximately 1500 - 3500 bar,

- the advancement speed of the rotating head with respect to the surface of the rubber layer to be crushed and disintegrated, or vice versa, is approximately 1 - 9, preferably 5 - 7 cm/second,

- the distance between the delivery point of the waterjet and the surface of the rubber layer to be crushed and disintegrated is approximately 10 - 35 mm.

2. Method according to claim 1 , wherein:

- said waterjet is delivered at a pressure of approximately 1800 - 2800 bar,

- said water jet comes out from a delivery section of a rotating head which rotates on itself at a rotation speed of approximately 500 - 1000 revolutions per minute,

- the distance between the delivery point of the waterjet and the surface of the rubber layer to be crushed and disintegrated is approximately 10 - 20 mm.

3. Method according to claims 1 or 2, wherein said rubber-containing product or article is a tyre, preferably an end-of-life tire of any vehicle or size.

4. Method according to claims 1 or 2, wherein said rubber-containing product or article comprises at least one among rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders.

5. Method according to one or more of the previous claims, wherein said water jet has a substantially flared shape.

6. Method according to one or more of the previous claims, wherein said water jet has a substantially triangular and/or fan-shaped conformation.

7. Method according to one or more of the previous claims, wherein the powder so obtained comprises granules (2) having a surface which, at least in part and preferably for the most part, is devulcanised.

8. Method according to one or more of the preceding claims, wherein said waterjet also contains ammonia.

9. Method according to one or more of the previous claims, wherein said water jet is impulsive, preferably activated/deactivated and/or modulated at a frequency of approximately 1000 - 2000 cycles per minute.

10. Method according to one or more of the previous claims, wherein said rubber to be crushed and disintegrated comprises a mixture with approximately 3 - 50% natural rubber.

11. Method according to one or more of the previous claims, wherein said product or article containing rubber is a tire and wherein said rubber layer to be crushed and disintegrated of said tire comprises a mixture with about 10 - 40% natural rubber.

12. Method according to one or more of the previous claims, wherein before crushing and disintegrating at least one rubber layer by sending at least one high pressure water jet, there is no cleaning and scratching phase of said rubber layer to be crushed and disintegrate.

13. Method according to one or more of the previous claims, wherein said method comprises a drying step, an exsiccation step and a screening step of the obtained powder.

14. Method according to one or more of the previous claims, wherein the water is removed from the obtained powder.

15. Method according to the previous claim, wherein the water removed from the powder is reused, preferably it is reused to feed said water jet.

16. Method according to one or more of the previous claims, wherein the water is removed from the powder by filtration.

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

18. Method according to one or more of the previous claims, wherein the water is removed from the powder by drying.

19. Method according to one or more of the previous claims, wherein said method also comprises in sequence:

- a filtration phase of the powder obtained by means of at least one filtering element, preferably a filter bag,

- a mechanical compression phase of the filtered powder,

- a drying phase of the compressed powder.

20. Method according to one or more of the previous claims, characterized by the fact that said phase wherein at least one rubber layer is crushed and disintegrated by sending at least one jet of high pressure water is implemented inside a container, preferably a transportable or self-propelled container.

21 . Method according to the previous claim, wherein said step of water removal from the obtained powder, preferably by filtration, is carried out inside said container.

22. Method according to one or more of the previous claims, characterized in that the flow rate of said water jet exiting the delivery section is 3 - 60 liters per minute, preferably 5 - 32 liters per minute.

23. Method according to one or more of the previous claims, characterized in that the water is removed from the powder so as to reach a humidity percentage of approximately 1 - 20%, preferably less than 2%

24. Rubber-based powder (1) which is obtained from the mechanical crushing of products or articles containing rubber, preferably tyres, rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, fenders in rubber or in general any other product or article containing rubber, characterized in that it comprises a plurality of granules (2) of irregular shape and having a devulcanised surface greater than 80%, more preferably greater than 95%.

25. Powder according to the previous claim, characterized in that said granules (2) are pedunculated.

26. Powder according to one or more of the previous claims, characterized in that said granules (2) are obtained by disintegrating tire rubber, preferably end-of-life tyres, with a high-pressure water jet.

27. Powder according to one or more of the previous claims, characterized in that said granules (2) are obtained by disintegrating the rubber of rubber conveyor belts, rubber belts, rubber tracks, rubber carpets, rubber flooring, rubber pipes, rubber fenders or in general any other product or product containing rubber.

28. Powder according to one or more of the previous claims, characterized in that said granules (2) mainly have dimensions of approximately 0.1 - 0.6 mm.

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

30. Rubber-based compound for tyres, characterized in that it comprises said powder (1 ) according to one or more of the previous claims in a quantity of approximately 5 - 30% of the total weight of the compound.

31. Compound according to the previous claim, characterized in that said powder (1 ) is mixed with the other ingredients of said compound, and wherein said other ingredients comprise natural rubber, synthetic elastomers, reinforcers such as for example carbon black.