Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/0026—Recovery of plastics or other constituents of waste material containing plastics by agglomeration or compacting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B13/00—Conditioning or physical treatment of the material to be shaped
  • B29B13/02—Conditioning or physical treatment of the material to be shaped by heating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B13/00—Conditioning or physical treatment of the material to be shaped
  • B29B13/06—Conditioning or physical treatment of the material to be shaped by drying
  • B29B13/065—Conditioning or physical treatment of the material to be shaped by drying of powder or pellets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/04—Disintegrating plastics, e.g. by milling
  • B29B17/0412—Disintegrating plastics, e.g. by milling to large particles, e.g. beads, granules, flakes, slices
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/12—Making granules characterised by structure or composition
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/16—Auxiliary treatment of granules
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
  • B29C67/02—Moulding by agglomerating
  • B29C67/04—Sintering
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/12—Making granules characterised by structure or composition
  • B29B2009/125—Micropellets, microgranules, microparticles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/16—Auxiliary treatment of granules
  • B29B2009/168—Removing undesirable residual components, e.g. solvents, unreacted monomers; Degassing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
  • B29B2017/0213—Specific separating techniques
  • B29B2017/0293—Dissolving the materials in gases or liquids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
  • B29B7/7476—Systems, i.e. flow charts or diagrams; Plants
  • B29B7/7495—Systems, i.e. flow charts or diagrams; Plants for mixing rubber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/80—Component parts, details or accessories; Auxiliary operations
  • B29B7/82—Heating or cooling
  • B29B7/823—Temperature control
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/80—Component parts, details or accessories; Auxiliary operations
  • B29B7/82—Heating or cooling
  • B29B7/826—Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/80—Component parts, details or accessories; Auxiliary operations
  • B29B7/84—Venting or degassing ; Removing liquids, e.g. by evaporating components
  • B29B7/845—Venting, degassing or removing evaporated components in devices with rotary stirrers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2021/00—Use of unspecified rubbers as moulding material

Definitions

• the present invention relates to the field of articles made from deodorized rubber granulates.
• the invention relates to a process for deodorizing vulcanized rubber granulates by steaming.
• the crushed materials are treated in a granulator where they are ground more finely to obtain aggregates.
• the aggregates come from very fine grinding of the gum included in the pieces of used tires, generally after extraction of the textile fibers and metal wires contained in the tires.
• the aggregates thus obtained have a size between 0.8 mm and 20 mm.
• the aggregates can then be ground more finely and dried to obtain rubber crumb.
• Document FR 2 475 458 describes a process for manufacturing recovered rubber articles by sintering which consists of depositing in a mold powder preferably mixed with a vulcanizing agent, alone or mixed with an accelerator.
• Document WO2020128212 describes a process for manufacturing recovered rubber articles by sintering, making it possible to avoid the use of any bonding agent.
• the powder particles used have a size not exceeding 800 pm.
• Document WO2020128213 describes a process for manufacturing recovered rubber articles by sintering comprising the following steps. Powder particles are mixed with solute particles. Then a molded object is produced by sintering this mixture. A step of bringing the molded object into contact with a solvent makes it possible to dissolve at least part of the solute particles, making it possible to obtain partial or total porosity of the molded object.
• Rubber granulates include volatile organic compounds trapped in the vulcanized rubber that will slowly evaporate and contribute to odors emitted by the object over several weeks, months or years depending on the size of the object.
• a process has thus been developed for deodorizing a vulcanized rubber granulate comprising steaming said granulate.
• the rubber granulate when subjected to the steaming treatment the rubber granulate comprises rubber in the vulcanized state.
• the rubber granulate still includes rubber in the vulcanized state.
• the process of the invention makes it possible to deodorize the rubber granulate while retaining its vulcanized state.
• the rubber granulate thus deodorized can be used as is for the manufacture of rubber objects, in particular by sintering.
• the subject of the invention is a process for deodorizing a rubber granulate comprising a step of steaming said rubber granulate, characterized in that the rubber granulate subjected to the steaming treatment comprises rubber in the vulcanized state, the rubber granulate being heated during the steaming step to a temperature between 55° C and 180° C, preferably between 60° C and 130° C, even more preferably between 65° C and 120° C, so particularly preferred between 75° C and 110° C, for a period between a minimum value and a maximum value as indicated in the table below:
• the pressure used during the steaming step is between 2*10 4 Pa and atmospheric pressure, preferably between 3*10 4 Pa and 5*10 4 Pa.
• the rubber granulate is in the form of particles whose average diameter D50 by volume is between 0.8 mm and 20 mm, preferably between 0.8 mm and 8 mm.
• the rubber granulate is a crumb of rubber in the form of particles whose average diameter D50 by volume is between 10 pm and 800 pm, preferably between 50 pm and 200 pm.
• the emission of total volatile organic compounds by the rubber granulate, after the steaming step is reduced compared to that of the rubber granulate before the steaming step.
• the reduction in the emission of total volatile organic compounds by the rubber granulate, after the steaming step is greater than 50% by weight, preferably greater than 70% by weight.
• the process for deodorizing the rubber granulate comprises a preliminary step of grinding a vulcanized rubber object, preferably used tires or pieces of used tires, to provide said rubber granulate.
• the invention also relates to a deodorized rubber granulate capable of being obtained according to the process as described above.
• the invention also relates to a process for manufacturing an object made of rubber granulate comprising the following successive steps: has. supply of a deodorized rubber granulate capable of being obtained according to the deodorization process as described above; b.optionally, preparation of a composition comprising said granulate and, for example, metallic, mineral or organic particles, said mineral or organic particles being able to be a salt, a saccharide, a protein soluble in water or a polymer soluble in the water ; vs. sintering the deodorized granulate or the composition comprising it in a mold; d. recovery of the object obtained at the end of step c.
• the deodorized rubber granulate from step a. is prepared by implementing the following successive steps: a1. supply of an aggregate comprising rubber in the vulcanized state; a2. deodorization of said granulate according to the deodorization process as described above.
• step c. directly follows the steaming step applied to the aggregate comprising vulcanized rubber during step a2. so that said aggregate is introduced into the mold for its shaping by sintering at a temperature above 30° C, preferably above 40° C.
• the process for manufacturing a rubber granulate object comprises a step prior to step a1. grinding a vulcanized rubber object, preferably used tires or pieces of used tires, to provide the aggregate comprising rubber in the vulcanized state.
• the invention also relates to an object made of deodorized rubber granulate capable of being obtained by the process as described above.
• the invention also relates to the use of the rubber granulate object as described above, for the manufacture of playing fields, athletics tracks, play areas, soles for shoes or solid casters, in particular casters for scooters, trolleys, self-balancing scooters or medical beds.
• vulcanized rubber we mean a rubber crosslinked with a sulfur-based crosslinking system.
• room temperature we mean a temperature ranging from 18° C to 22° C.
• aggregate and “aggregates” are interchangeable.
• “Granulate” or “aggregates” means tire shreds processed in a granulator where they are ground more finely.
• the aggregates thus obtained generally have an average diameter D50 in volume of less than 20 mm.
• the aggregates obtained have an average diameter D50 by volume of between 0.8 mm and 20 mm. These aggregates can then be ground more finely and dried to obtain rubber crumbs whose average diameter D50 by volume is less than 800 pm.
• “granulate” or “aggregates” therefore also means, where appropriate, the rubber crumb thus obtained.
• particles we mean particles which have a size, namely their average diameter D50 in volume, of a few tens of microns to a few millimeters.
• the average diameter D50 of the aggregate particles is an average diameter D50 in volume and can be measured by particle size analysis by laser diffraction or by sieve analysis for particles whose D50 is greater than 1 mm. Particles whose diameter is less than D50 represent 50% by volume of the volume of all particles.
• sintering of rubber granulates is meant a step of shaping a predetermined quantity of granulate by heating to a temperature lower than that of vulcanization of the grains composing it and at the same time putting this quantity of granulate under pressure. granulate in the cavity of a mold.
• FIG. 1 represents the concentration of total volatile organic compounds, expressed in ppm (parts per million), emitted by the different vulcanized rubber granulates recovered from the examples before and after implementation of the deodorization process according to the invention.
• FIG. 2 represents the results of the sensory evaluation of the subjective concentration of odors emitted by the different vulcanized rubber aggregates recovered from the examples before and after implementation of the deodorization process according to the invention. On the y-axis is reported the number of points obtained following the scoring of the trained panel. The numbers are therefore unitless.
• the inventors have developed a process for deodorizing a rubber granulate while retaining its vulcanized state.
• Rubber aggregates come from grinding or micronization of new cooked rubber compositions or already used for a first application, for example in tires. They are advantageously a material recycling product. They are thus advantageously obtained from the crushing of already vulcanized tires, whether used or new.
• a tire is chosen from tires intended to equip a two-wheeled vehicle, a passenger vehicle, or even a so-called “heavy goods vehicle” (that is to say metro, bus, off-road vehicles, road transport vehicles such as trucks, tractors, trailers), or even airplanes, civil engineering, agrarian or handling equipment.
• the aggregate used is that obtained by grinding a part previously detached from the tire, for example from a tread, sidewalls, etc. or it is obtained by crushing the entire tire. In the latter case, the aggregate also advantageously undergoes a step during which the textile or metallic residues present in the tire are removed.
• Rubber granulate is in the form of particles.
• the rubber granulate is in the form of particles whose average diameter D50 by volume is between 0.8 mm and 20 mm, preferably between 0.8 mm and 8 mm.
• the rubber granulate is a crumb of rubber in the form of particles whose average diameter D50 by volume is between 10 pm and 800 pm, preferably between 50 pm and 200 pm.
• the rubber granulate whether it is in powder form or not, is in the form of individual particles and not a paste comprising even partially vulcanized rubber.
• the aggregates are advantageously simple crushed rubber, without any other treatment, that is to say that the aggregates have not undergone any other treatment than grinding operations aimed at reducing their size and, where appropriate, at extract the residues of textile and mechanical reinforcements present.
• the aggregates have not been subjected to a chemical modification of functionalization or devulcanization.
• the aggregates have not been subjected to modifications by biological and/or chemical treatment.
• So-called primary crushing makes it possible to obtain, from tires, pieces of sheared tires having different sizes (D50) generally between 25 mm and 350 mm and an average composition identical to that of the original whole tire.
• a granulation step makes it possible to reduce the size of the crushed materials obtained at the end of the primary grinding.
• Granulation includes a first dissociation step consisting of reducing the size of the crushed materials to obtain a particle size sufficient to allow the separation of rubbers, textile and metal reinforcements. Once separated, the materials are sorted during a second step. When the aggregates have a size less than 2.5mm, the sorting stage is facilitated and it is generally possible to obtain aggregates free of metal and textile residues.
• the aggregates obtained generally have a size between 0.8 mm and 20 mm.
• the aggregates can also be ground more finely and dried to obtain rubber crumbs whose particles have a size less than 800 pm.
• this process makes it possible to obtain powders containing only the rubber composition.
• knife mills composed of a rotor, a stator and a grid makes it possible, through successive grinding, to reduce the particle size.
• This type of granulator includes fins allowing the material to be crushed to be broken up, rollers allowing the material to be crushed and forcing it to pass through a die.
• the aggregate has an acetone extract of between 3 and 15% by weight, more preferably included in a range ranging from 3 to 10% by weight. Also, it is preferred that the aggregate has a chloroform extract of between 3 and 20% by weight, more preferably included in a range ranging from 5 to 15% by weight.
• the chloroform extract of the rubber granulate has a mass-average molecular mass (Mw) of less than 10,000 g/mol, preferably less than 8,000 g/mol.
• the ratio of the chloroform extract to the acetone extract is less than 1.5.
• the aggregate is advantageously free of textile or metallic residues present in the tire.
• the aggregates are preferably made up of a composition based on an elastomer and a filler. They can also include all the ingredients usually used in rubber compositions such as plasticizers, antioxidants, vulcanization additives, etc.
• the aggregate comprises an elastomer, preferably a diene elastomer.
• This elastomer preferably represents at least 30% by mass, more preferably at least 35% by mass, even more preferably at least 45% by mass of the weight of the aggregate, percentage determined according to standard ASTM E1 131. It is preferentially chosen from the group consisting of polybutadienes, polyisoprenes including natural rubber, butadiene copolymers and isoprene copolymers. More preferably the molar rate of units of diene origin (conjugated dienes) present in the diene elastomer is greater than 50%, preferably between 50% and 70%.
• the aggregate contains between 5% and 80% by weight of filler, more preferably between 10% and 75%, and very preferably between 15% and 70%.
• filler we mean here any type of filler, whether it is reinforcing (typically with nanometric particles, and preferably of weight average size less than 500 nm, in particular between 20 nm and 200 nm) or whether it is non-reinforcing or inert (typically with micrometric particles, and preferably of weight average size greater than 1 pm, for example between 2 pm and 200 pm).
• the weight average size of nanometric particles is measured in a well-known manner of those skilled in the art (for example, according to application W02009/083160 paragraph 1.1).
• the weight average size of micrometric particles can be determined by mechanical sieving.
• fillers known as reinforcing by those skilled in the art mention will be made in particular of carbon black or a reinforcing inorganic filler such as silica or alumina in the presence of a coupling agent, or mixtures thereof.
• the aggregates include vulcanized rubber, that is, rubber cross-linked with a sulfur-based cross-linking system.
• reaction products or residues of at least one vulcanization accelerator and, optionally, of various known vulcanization activators such as zinc oxide, stearic acid or equivalent compound such as the salts stearic acid and transition metal salts, guanidic derivatives (in particular diphenylguanidine), or even known vulcanization retarders.
• various known vulcanization activators such as zinc oxide, stearic acid or equivalent compound such as the salts stearic acid and transition metal salts, guanidic derivatives (in particular diphenylguanidine), or even known vulcanization retarders.
• accelerators of the thiazole type as well as their derivatives, accelerators of the sulfenamide, thiuram, dithiocarbamate, dithiophosphate, thiourea and xanthate types.
• MBTS 2-mercaptobenzothiazyl disulfide
• CBS N-cyclohexyl-2-benzothiazyl sulfenamide
• DCBS N,N-dicyclohexyl- 2-benzothiazyl sulfenamide
• TBBS N-ter-butyl-2-benzothiazyl sulfenamide
• TZTD tetrabenzylthiuram disulfide
• ZBEC zinc dibenzyldithiocarbamate
• the aggregate may contain all the other usual additives, or their reaction products or residues, which are used in a rubber composition, particularly for tires.
• these usual additives we can cite liquid or solid plasticizers, non-reinforcing fillers such as chalk, kaolin, protective agents.
• These additives can also be found in the aggregate in the form of residue or derivative, since they may have reacted during the stages of manufacturing the composition or crosslinking the composition from which the aggregate is derived.
• the objective of the process is to reduce the emission of total volatile organic compounds from the rubber granulate.
• the steaming step according to the deodorization process of the invention is applied to a rubber granulate comprising vulcanized rubber as has just been described.
• the rubber granulate subjected to the steaming treatment has not undergone any devulcanization step, even partial.
• a first object of the invention thus relates to a process for deodorizing a rubber granulate comprising a step of steaming said granulate, characterized in that the rubber granulate subjected to the steaming treatment comprises rubber in the vulcanized state , the rubber granulate being heated during the steaming step to a temperature between 55° C and 180° C, preferably between 60° C and 130° C, even more preferably between 65° C and 120° C, particularly preferred manner between 75° C and 110° C for a period between a minimum value and a maximum value as indicated in the table below:
• the steaming step is carried out in any closed heat treatment device, in particular an oven, making it possible to heat the aggregate homogeneously and regularly, if necessary under a partial vacuum.
• Ovens with natural or forced convection, advantageously with forced convection, are preferred.
• Heating by infrared radiation does not allow the aggregate to be heated sufficiently homogeneously.
• the aggregate can be set in motion in the heat treatment device.
• the heat treatment device may include a rotating tube with blades allowing the granulate particles to rise and then fall and so on inside the tube.
• the steaming step is carried out without applying mechanical stress of the kneading or shearing type to the rubber aggregates inducing a change in their size.
• the temperature within the heat treatment device is maintained at a temperature above ambient temperature and below 180°C, in order to avoid degradation of the rubber.
• the temperature in the heat treatment device is between 55° C and 180° C, preferably between 60° C and 130° C, even more preferably between 65° C and 120° C, particularly preferred between 75°C and 110°C.
• the temperature corresponds to the temperature measured inside the heat treatment device, using any suitable means, for example a temperature probe.
• the steaming can be carried out under vacuum, in particular under 10% to 80% partial vacuum, advantageously under 50% to 70% partial vacuum.
• the pressure of the air inside the heat treatment device advantageously varies from 20,000 Pa to 90,000 Pa, more advantageously from 30,000 Pa to 50,000 Pa.
• the pressure used during the steaming step is thus between 2*10 4 Pa and atmospheric pressure, preferably between 3*10 4 Pa and 5*10 4 Pa.
• the duration of the heat treatment step depends on multiple factors such as the type of device used, the quantity of aggregate to be deodorized, the size of the aggregate to be deodorized and the temperature of the aggregate during treatment.
• the duration of the heat treatment step can range from a few minutes, for example 5 minutes, to several weeks, for example 3 weeks.
• the duration of the deodorization step depends particularly on the temperature at which the deodorization step is carried out.
• the duration of the deodorization step is thus chosen so as to avoid reversion of the vulcanized rubber from the granulate, that is to say so as to avoid degradation of the rubber.
• the maximum duration of the deodorization step that is to say, not causing reversion of the rubber, can easily be determined by means of charts available to those skilled in the art.
• the duration of the deodorization step must also be sufficient to allow the deodorization of the rubber granulate.
• the steaming step does not include devulcanization means.
• the process according to the invention makes it possible to deodorize the rubber granulate while retaining its vulcanized state.
• the implementation of thermal processes with sufficiently high temperatures can also result in reversion of the rubber granulate.
• the steaming step is carried out in the absence of devulcanization agent.
• a devulcanization agent or fragmentation agent let us cite for example the agents disclosed in application EP3541867 ⁇ 1 such as hexadecyl amine (HD ⁇ ) or even diphenyldisulfide (DPDS).
• the steaming step is carried out on the rubber aggregates alone, in the absence of any other component.
• the steaming step is carried out without applying mechanical stress such as mixing or shearing, inducing devulcanization of the rubber in the aggregates.
• the deodorization process may be a process consisting of continuously supplying the heat treatment device with the granulate to be deodorized. The granulate thus deodorized is then continuously recovered at the outlet of the heat treatment device.
• the deodorized granulate as described above can then be used for the manufacture of rubber objects.
• the fact that it is still vulcanized allows its direct use, without the need to add vulcanizing agents in particular.
• Each type of aggregate is placed in a static oven for 11 days, at a temperature of 65° C and under a pressure of 900 mbar.
• the values appearing on the ordinate are relative values and it is the drop in this value after steaming (expressed as a percentage) which must be taken into account to evaluate the effectiveness of the deodorization process.
• the aggregates after steaming have a lower subjective odor level than the untreated aggregates.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

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• 2022
  • 2022-09-09 FR FR2209079A patent/FR3139494B1/fr active Active
• 2023
  • 2023-09-08 US US19/109,858 patent/US20260084344A1/en active Pending
  • 2023-09-08 WO PCT/FR2023/051357 patent/WO2024052629A1/fr not_active Ceased
  • 2023-09-08 EP EP23776431.1A patent/EP4584067A1/de active Pending
  • 2023-09-08 CN CN202380064736.2A patent/CN120265443A/zh active Pending

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