Method for manufacturing raw materials for the production of shoes, wherein the raw materials are derived from batches of recycled shoes, apparatus for carrying out the method, and raw material for the production of shoes obtained according to the method

Abstract

The present invention relates to a method according to the preamble of claim 1. In the footwear industry, there is an increasing need for sustainable production processes and the reuse of materials. However, recycling shoes presents a challenge due to the complex composition of different materials used in shoes. Existing recycling processes are often unable to effectively separate the different materials with high purity. The invention solves this problem by providing an innovative method for recycling shoes, whereby different fractions with high purity are obtained. These fractions can subsequently be processed into high-quality raw materials for the production of new shoes.

Description

[0001] METHOD FOR MANUFACTURING RAW MATERIALS FOR THE PRODUCTION OF SHOES, WHEREIN THE RAW MATERIALS ARE DERIVED FROM BATCHES OF RECYCLED SHOES, APPARATUS FOR CARRYING OUT THE METHOD, AND RAW MATERIAL FOR THE PRODUCTION OF SHOES OBTAINED ACCORDING TO THE METHOD

[0002] The present invention relates to a method according to the preamble of claim 1.

[0003] In the footwear industry, there is an increasing need for sustainable production processes and the reuse of materials. However, recycling shoes presents a challenge due to the complex composition of different materials used in shoes. Existing recycling processes are often unable to effectively separate the different materials with high purity.

[0004] The invention solves this problem by providing an innovative method for recycling shoes, whereby different fractions with high purity are obtained. These fractions can subsequently be processed into high-quality raw materials for the production of new shoes.

[0005] To this end, the method according to the invention is characterized in that the method comprises an intermediate step 1 a) between step 1 ) and step 2): step 1a) sorting the shoes to be recycled by shoe type and / or brand into different batches. Sorting the shoes to be recycled into batches based on shoe type and / or brand prior to processing enables more efficient and more targeted recycling, resulting in fractions of higher quality.

[0006] The table below shows which materials are used for each component of the shoe:

[0007] The first column lists the shoe parts, such as Outsole, Midsole, Insole, Upper.

[0008] Outsole

[0009] This is the bottom layer of the shoe that comes into direct contact with the ground.

[0010] Midsole

[0011] This layer is located between the outsole and the insole and often provides cushioning and comfort.

[0012] Insole This is the inside of the shoe on which the foot rests. It is also called the footbed.

[0013] Upper

[0014] This refers to the entire upper part of the shoe that covers and encloses the foot.

[0015] The abbreviations for the materials are explained below.

[0016] EVA (Ethylene Vinyl Acetate):

[0017] EVA is a synthetic material that is widely used for soles. It is lightweight, resilient and provides good cushioning. EVA soles are durable, wear-resistant and flexible, allowing them to follow the natural movement of the foot.

[0018] SBR (Styrene-Butadiene Rubber): This is a type of synthetic rubber that is often used in shoe soles because of its durability and wear resistance.

[0019] ETPU (Expanded Thermoplastic Polyurethane):

[0020] A lightweight, elastic material that is often used in sports shoes for cushioning and energy return.

[0021] PA (Polyamide):

[0022] Also known as nylon, this material is often used in the upper part of shoes because of its strength and durability.

[0023] NBR (Nitrile Butadiene Rubber):

[0024] A synthetic rubber that is oil and fuel resistant, often used in work shoes.

[0025] PVC (Polyvinyl Chloride):

[0026] A versatile plastic that is used in various parts of shoes, especially in waterproof or weatherresistant models.

[0027] TPU (Thermoplastic Polyurethane):

[0028] A flexible, wear-resistant material that is often used in soles and other shoe components that require durability.

[0029] PU (Polyurethane):

[0030] A versatile material that is used in both soles and in the upper part of shoes.

[0031] TPE (Thermoplastic Elastomer):

[0032] TPE is a versatile material that combines properties of both rubber and plastic: TPE is often used in applications such as shoe soles, handles, and medical equipment.

[0033] PP (Polypropylene):

[0034] PP is a thermoplastic polymer: It is stiffer and harder than TPE, but still relatively lightweight.

[0035] By pre-sorting by type of shoe or brand of shoe, it is possible to obtain a foam and / or rubber fraction with high purity using the appropriate shoe recycling process, such as: a foam fraction consisting solely of:

[0036] EVAor ETPU or PU a rubber fraction consisting solely of: SBR or NBR orTPR.

[0037] Materials that can occur both as foam and in non-foamed form (rubber-like)

[0038] 1 . TPU (Thermoplastic Polyurethane)

[0039] TPU can be used in both solid and foamed form.

[0040] 2. ETPU (Expanded Thermoplastic Polyurethane)

[0041] ETPU is a foamed version of TPU and is therefore considered foam.

[0042] The other materials are not officially foam or rubber but can be sorted as such through the appropriate recycling process.

[0043] Preferably, in step 1) a process is selected that yields fractions of foam, rubber, textile, leather, each with a high purity or homogeneity of at least 80%, preferably above 90%, and in particular above 95%.

[0044] By producing fractions with high purity (80-95%), the recycling process becomes significantly more efficient: Pure fractions can thereby be converted into recycled materials of high quality, which are better suited for reuse in new products. Pure recycled materials also have a broader range of applications and can be used more often as a replacement for virgin materials. Pure material fractions generally have a higher market value than mixed or contaminated streams. It reduces the need for further purification steps, which can lower the overall recycling costs.

[0045] By focusing on high purity already in the first step, the entire recycling process is optimized. This differs from conventional methods that often only pursue purification in later stages. This early focus on purity can lead to a reduced need for energy-intensive purification steps later in the process and the ability to apply more advanced recycling techniques to purer fractions.

[0046] In a first embodiment of the method according to the invention, the method comprises the further steps: step 3) extruding the foam fraction from step 2) in an extruder into a foam ribbon; step 4) allowing the foam ribbon to cool; step 5) pelletizing the foam ribbon into foam pellets.

[0047] An extruder makes it possible to process the foam fraction continuously, resulting in an efficient and uninterrupted production process.

[0048] After leaving the extruder, the foam ribbon is cooled in a controlled manner. This is a critical step because it stabilizes the structure of the foam, prevents deformation of the material and improves processability for the next step.

[0049] In this final step, the cooled foam ribbon is processed into pellets. The ribbon is hereby cut into small, uniform pieces. The size of the pellets is optimized for further processing. This format makes it easy to dose and mix the material for future use.

[0050] Preferably, the foam fraction is processed in an extruder under the following specific conditions, wherein the temperature is between 130 and 260°C and a pressure prevails in the extruder of 20-75 bar.

[0051] These parameters are crucial for successfully processing the foam. The high temperature ensures that the foam melts and becomes liquid, while the pressure helps with mixing and homogenizingthe material.

[0052] Prior to the extrusion process, the foam fraction can be pulverized. This is particularly important if the foam fraction comprises elastic foam particles. Elastic foam particles cause problems in the extruder. By first pulverizing these particles, there are no longer any elastic particles in the foam fraction. This increases the homogeneity of the foam material and leads to better processing in the extruder.

[0053] Preferably, in the first embodiment of the method according to the invention in step 3) during extrusion, unused or new foam is added to the extruder in a predetermined ratio. This can help to: improve the quality of the end product achieve specific properties (for example density or elasticity) compensate for any degradation of the recycled foam material.

[0054] Preferably, the unused or new foam is of the same type of foam as the foam fraction that the process has yielded.

[0055] In a second embodiment of the method according to the invention, the method comprises the further steps: step 6) extruding the rubber fraction from step 2) in an extruder into a rubber ribbon, wherein the temperature of the rubber fraction is between 130 and 260°C and the rubber fraction is under a pressure of 150-300 bar, such that the rubber fraction devulcanizes during extrusion; step 7) allowing the rubber ribbon to cool; step 8) pelletizing the rubber ribbon into rubber pellets;

[0056] The rubber fraction is processed in an extruder under the following specific conditions, wherein the temperature is between 130 and 260°C and a pressure prevails in the extruder of 150-300 bar. These parameters are crucial for successfully processing the rubber: The high temperature and pressure ensure devulcanization of the rubber. Devulcanization is the process whereby the sulphur bridges between the polymer chains are broken, making the rubber processable again.

[0057] Preferably, in the second embodiment of the method according to the invention in step 6) during extrusion, unused or new rubber is added to the extruder in a predetermined ratio. This can help to: improve the quality of the end product achieve specific properties (for example density or elasticity) compensate for any degradation of the recycled rubber material.

[0058] Preferably, the unused or new rubber is of the same type of rubber as the rubber fraction that the process has yielded.

[0059] The table below describes different compounds (composite materials) that are produced from recycled shoes, together with the percentages of recycled and new materials that are used.

[0060] Post consumer Percentage Added Materials Percentage

[0061] Materials

[0062] The table shows nine different compounds: EVA, TPU, PA, eTPU, TPE / PP, NBR, SBR and

[0063] PVC. For each compound, three columns are shown:

[0064] 1 ) Post consumer Materials Percentage: This is the percentage of recycled foam or rubber material from used shoes.

[0065] 2) Added Materials: This is the added new or unused material. 3) Added Materials Percentage: This is the percentage of new (virgin) material that is added.

[0066] The same range of percentages applies to all compounds:

[0067] The recycled material varies from 29.5% to 98%.

[0068] The added new material varies complementarily from 70.5% to 2%.

[0069] This means that the compounds can be flexibly composed, depending on the desired properties and quality of the end product.

[0070] For EVA, two options are given: one with regular virgin EVA and one with "Green EVA" as added material.

[0071] This table illustrates the flexibility of the recycling process, whereby a high percentage of recycled material can be used (up to 98%), but also the possibility exists to add more new material if necessary for specific applications or quality requirements. This aligns with the previously discussed importance of being able to add new materials in the recycling process.

[0072] In a third embodiment of the method according to the invention, the method comprises the further steps: step 9) opening up the textile fraction, wherein the textile fraction is pulled apart by means of needles; step 10) fiberizingthe opened textile fraction from step 9); step 11 ) removing contamination from the fibers from step 10); step 12) making a sliver from the cleaned fibers from step 11 ); step 13) spinningyarn from the sliver from step 12) with a predetermined thickness;

[0073] In step 9), the textile fraction is pulled apart with the aid of needles. This process has the purpose of disentangling and loosening fibers, separating any knots or clumped parts and preparing the fibers for further processing.

[0074] After opening up, in step 10) the fibers are further separated. This process separates the individual fibers, removes any remaining knots or clumps and creates a more homogeneous fiber mass.

[0075] In step 11 ), impurities are removed from the fibers. This can include: removing non-textile particles separating different fiber types if necessary removing dust and other small contaminants

[0076] The cleaned fibers are subsequently processed in step 12) into a sliver. A sliver is a loose, unspun strand of fibers. This process:

[0077] Aligns the fibers in one direction Creates a continuous strand of fibers

[0078] Prepares the material for the spinning process

[0079] Finally, in step 13) the sliver is spun into yarn with a predetermined thickness. This includes:

[0080] Further stretching and twisting of the fibers

[0081] Creating a continuous thread with the desired thickness

[0082] Winding the yarn onto spools

[0083] Preferably, in the third embodiment of the method according to the invention, step 11 ) has the following subsequent step: step 11a) adding recycled textile and / or polyester obtained from another process;

[0084] This has the purpose of:

[0085] Improvingthe quality of the end product

[0086] Achieving specific properties

[0087] Increasing the amount of usable material

[0088] The above-mentioned steps guarantee high-quality recycling. The method makes it possible to recycle textile into new yarns, which is a high-qualityform of reuse. Through the possibility of adding recycled material, the quality and composition of the end product can be adjusted.

[0089] Recycling textile fibers reduces the environmental damage that results from the extraction of raw materials and processing into new textile fibers. The method contributes to a more circular textile industry by redeploying used materials in the production chain.

[0090] This detailed processing of the textile fraction enables one to produce high-quality recycled yarns that can be used in new textile products, including possibly new shoes. This contributes to a more sustainable and circular approach in the textile and footwear industry.

[0091] In a fourth embodiment of the method according to the invention, the method comprises the further steps: step 14) pulverizing the leather fraction; step 15) sieving the pulverized leather fraction from step 14); step 16) mixing the sieved and pulverized leather fraction from step 15) with a binder into a leather mixture; step 17) rolling and milling the leather mixture from step 16); step 18) cutting the rolled rolls from step 2a-12) into sheets of leather. In step 14), the leather fraction is pulverized into a fine powder. This process has the purpose of reducing the leather particles to a processable size, so that a homogeneous material is created for further processing.

[0092] Subsequently, in step 15) the leather powder is sieved. This process ensures that the leather particles have a uniform particle size. Additionally, any larger pieces or impurities are removed from the leather powder. This creates a consistent quality of the leather powder for further processing.

[0093] Then, in step 16) the sieved leather powder is mixed with a binder into a leather mixture. This step is crucial because: the binder bonds the leather particles together it improves the formability of the material it influences the properties of the end product (for example flexibility or strength).

[0094] The leather mixture is subsequently rolled and milled in step 17). This process distributes the leather mixture evenly and creates a consistent thickness. This improves the structural integrity of the material.

[0095] Finally, in step 19) the rolled rolls are cut into sheets of leather. This results in: usable formats for further applications standardization of the end product easier processing in subsequent processes

[0096] This method for processing the leather fraction offers various advantages:

[0097] Reuse of material: Recycled leather from old shoes can be reused, which contributes to a circular economy.

[0098] Flexibility in properties: Through the choice of binder and processing, the properties of the end product can be adjusted.

[0099] Efficient processing: The process enables large-scale processing of recycled leather.

[0100] Versatility in applications: The resulting leather sheets can be used in various products, possibly including new shoes or other leather goods products.

[0101] Waste reduction: By recycling leather, the amount of waste is reduced and the life cycle of the material is extended.

[0102] This processing of the leather fraction contributes to a more sustainable and circular approach in the leather goods industry, whereby used leather can be converted into new, usable materials. In a fifth embodiment of the method accordingto the invention, the method comprises the further steps: step 19) heating the collected fiber fraction;

[0103] Step 20) pelletizing the heated fiber fraction from step 19).

[0104] In step 19), the collected fiber fraction is heated. This process has various purposes: Removing moisture: Heating helps to remove any remaining moisture from the fibers, which is important for further processing.

[0105] Softening the adhesive: The adhesive present in the fiber fraction becomes softer through heating, which facilitates further processing.

[0106] Preparing for pelletization: By heating, the fibers and the adhesive become more plastic, which is favorable for the pelletization process.

[0107] After heating, the fiber fraction is pelletized in step 20). This process includes: Compression: The heated fibers are pressed together in a pelletizing machine. Formation: Through the combination of pressure and the previously applied heat, the fibers and the adhesive are bonded together into small, solid pellets.

[0108] Cooling: After pressing, the pellets are cooled to retain their shape.

[0109] This method offers various advantages: it enables material recycling of the fiber fraction that might otherwise be considered waste, significantly reduces the volume for easier storage and transport, creates uniform pellets for easier processing and dosing, and retains certain properties of the original material by processing fibers and adhesive together. The pellets produced from the fiber fraction can potentially be used in various applications, such as filler material in new shoe soles or other shoe components, in the production of composite materials, as raw material for thermoplastic products, or even as fuel in industrial processes due to the presence of fibers and polymers (adhesive). This method for processing the fiber fraction with adhesive contributes to a more circular approach in the footwear industry, whereby even materials that are difficult to separate can be usefully reused.

[0110] The described methods for processing the different fractions (foam, rubber, textile and leather) offer an innovative and sustainable approach for the reuse of materials from old shoes. By means of advanced techniques such as extrusion, pelletization and devulcanization, high- quality raw materials are produced that not only contribute to a circular economy, but also reduce the ecological impact of the footwear industry. These processes make it possible to transform waste into valuable products, whereby the life cycle of materials is extended and new opportunities arise for sustainable production. The result is an efficient and effective way to redeploy recycled materials, which benefits not only the industry, but also the environment and society as a whole.

[0111] Selecting the appropriate recycling process in step 1 ) is crucial for obtaining fractions with high homogeneity. The chosen process must be arranged to process shoes and / or shoe parts into fractions of foam, rubber, textile and leather, each with a high purity or homogeneity of at least 95%.

[0112] This high degree of purity is important for various reasons:

[0113] Quality of recycled materials: Pure fractions lead to high-quality recycled materials that are suitable for use in new products, possibly even in new shoes.

[0114] Efficiency of subsequent processes: Homogeneous fractions simplifyfurther processing, such as extrusion or pelletization, which leads to a more efficient recycling process.

[0115] Value of recycled materials: Pure fractions generally have a higher market value, which improves the economic feasibility of the recycling process.

[0116] Applicability: The purer the fractions, the broader the range of possible applications for the recycled materials.

[0117] Environmental benefits: By enabling high-quality recycling, the need for new raw materials is reduced and the life cycle of materials is extended.

[0118] By focusing on a recycling process that yields fractions with high homogeneity, the foundation is laid for an effective circular economy in the footwear industry, whereby materials retain their value and can be redeployed in high-quality applications.

[0119] Adding new materials during the recycling process, as described above, is an important aspect of the invention. This has various advantages:

[0120] Quality improvement: By adding new material, the quality of the recycled product can be improved or optimized. This is especially important in the processing of the foam and rubber fractions, where the addition of new material is explicitly mentioned.

[0121] Adjustment of properties: Blending in new material makes it possible to precisely tune the properties of the end product to the desired application. This increases the applicability of the recycled material.

[0122] Compensation for degradation: Recycled material can deteriorate in quality after multiple cycles of use and recycling. Adding new material can compensate for this degradation and extend the life of the material.

[0123] Improvement of processability: In some cases, the addition of new material can improve the processability of the recycled material, which makes the production process more efficient.

[0124] Market acceptance: Products made from a mixture of recycled and new material can sometimes be better accepted in the market, because they combine the advantages of both.

[0125] Preferably, after pelletization, the pellets are further reduced to granules of 1-45 mm by, for example, grinding. This smaller dimension increases the surface-to-volume ratio, which enables faster heat transfer. This is particularly important for further pyrolysis of the material. It results in more efficient pyrolysis with shorter processing time and more complete thermal decomposition. The uniform granule size ensures uniform heat distribution, prevents incomplete conversion, and improves handling in dosing systems.

[0126] Preferably, the granules are dried to 0.1-0.5 weight percent moisture at 80-150°C. This low moisture content is crucial for pyrolysis efficiency, because moisture otherwise requires energy for evaporation and causes undesired reactions. Dry material prevents foam formation during pyrolysis, has longer storage stability, and leads to purer products. It is energetically more efficient to remove moisture beforehand at low temperature than during pyrolysis at high temperature.

[0127] In a preferred embodiment of the method according to the invention, the pellets or granules are pyrolyzed in a reactor under inert atmosphere, for example nitrogen and / or argon, preferably at 360-395°C and substantially without oxygen. The thermal depolymerization breaks down polymer chains into smaller molecules, which yields three separate streams: solids (for example char), liquids (for example pyrolysis oil), and gases. This valorises waste streams into valuable chemical raw materials for a circular economy. The gases can also serve as process fuel, which makes the system energy-neutral or -positive.

[0128] Preferably, the hot pyrolysis gases pass through multiple condensers at different temperatures for fractional condensation. In a configuration with, for example, two condensers, which are set at 20°C-60°C and 60°-120°C respectively (for foam fractions), this results in production of a light (short hydrocarbon chains) and a heavy oil fraction (with long hydrocarbons).

[0129] Preferably, the lightest oil fraction is recycled as raw material for foam or rubber for shoe production, where it functions as raw material for the production of plasticizer, polymers or adhesives. This creates maximum circularity whereby carbon from old shoes returns to new shoes, instead of linear discharge to fuel. It reduces virgin material requirements, reduces costs, and significantly lowers the carbon footprint. The light fraction has higher value as raw material than as fuel and transforms a waste stream into a valuable raw material stream.

[0130] Preferably, the char is used as filler in polymers, pigment carrier, or after activation as adsorbent.

[0131] The method is optimized for ethylene-vinyl acetate (EVA) foam, the dominant shoe sole material in more than 60% of sports shoes. EVA's specific melting temperatures match perfectly with the process parameters for pyrolysis (preferred temperature of 250°C-550°C, most preferred 360°C-390°C). The enormous availability and uniform composition guarantee longterm feasibility.

[0132] The invention also relates to an integrated apparatus for carrying out the method according to the invention. The apparatus combines a recycling system, sorting means, extrusion means, cooling means and palletisation means for complete processing of shoes into pellets. The recycling system produces fractions with 80-95% purity, significantly higher than conventional recycling (60-70%). This solution with coordinated components eliminates external processing, guarantees consistent quality, and enables batch traceability. The high purity leads to higher market value and suitability for critical applications. The extrusion means are preferably optimized for foam, wherein the operational parameters lie in the melting range of EVA with optimal viscosityfor ribbon formation. The pulverization means between recycling system and extruder reduce foam to powder form. The larger surface area ensures faster, more homogeneous melting, which increases throughput. This enables a lower extrusion temperature, which saves energy and reduces degradation. Powder feeds more constantly into the extruder, lowers motor load, and eliminates incompletely melted particles for a more consistent end product.

[0133] A controlled feed system doses virgin foam to recyclate in predetermined ratios. This enables flexible product quality whereby different virgin percentages serve different market segments: from high-end applications with virgin to commodity with 100% recyclate.

[0134] For rubber, extreme conditions are used: 130-260°C at 150-300 bar to achieve devulcanization. The high temperature, pressure and shear forces break sulphur crosslinks, which partially converts vulcanized rubber (normally irreversible) to thermoplastic material. Devulcanized and re-vulcanized rubber achieves 70-90% of original properties versus 30-50% for ground rubber. This solves the biggest problem of rubber recycling and enables actual recycling instead of downcycling. Analogous to foam, virgin rubber can be dosed to devulcanized recyclate. Blends often give better properties than 100% recyclate. This maximizes recyclate use within quality restrictions. A granulation installation further reduces pellets to 1-45 mm for uniform size. This increases pyrolysis efficiency with shorter residence time (5-120 minutes) and higher throughput.

[0135] Drying means reduce the moisture content to 0.1-0.5 weight percent. This is crucial because moisture causes energy loss, steam formation, hydrolysis reactions and lower pyrolysis oil yield. Drying at 100-150°C is, for example, much more efficient than evaporating moisture at 300-600°C in the reactor.

[0136] The pyrolysis reactor has three separate outlets for char, liquids and gases. This in-situ separation prevents cross-contamination, enables separate processing per stream, and facilitates continuous operation without process interruption. Each product can go directly to downstream processing without intermediate storage, which gives efficient downstream processing. The independent control per stream optimizes yield (50 to 85 weight percent) and quality, for example higher temperature for char expulsion at lower temperature for oil condensation.

[0137] Multiple condensers at different temperatures realize fractional condensation whereby heavy, middle and / or light fractions are collected separately. Each condenser can be controlled independently for optimal efficiency. The cascade configuration maximizes recovery of condensable components.

[0138] Recycle means transport light oil fraction to shoe production. On-site recycling eliminates transport costs and logistical complexity, with short feedback loops for quality control. This makes substantial use of recycled material technically and economically feasible.

[0139] Processing means comprise grinding systems, activation facilities and / or compounding installations for char processing. Integrated processing eliminates transport, increases economic feasibility, and transforms a problematic waste stream into valuable products with flexible application.

[0140] All components are preferably optimized for EVA: the recycling system uses EVA's specific density for separation, extrusion means have EVA-adapted screw geometry and temperature profiles, the pyrolysis reactor is arranged for EVA's two-step decomposition (preferably 340°C to 420°C), and the condensation system has corrosion-resistant materials for acetic acid recovery. This EVA-specific optimization achieves higher efficiency and yields.

[0141] The invention also relates to a raw material for the production of shoes obtained according to the method according to the invention: such as pellets / granules, pyrolysis oil fractions and processed char products. The distinctive feature is their origin from recycled shoes via a controlled process with traceable properties. Practical application

[0142] A practical application of the method described above is thermal decomposition of EVA footwear waste derived from post-consumer, pre-consumer and factory waste. The method is carried out by pyrolysis under inert gas, under vacuum and in the absence of added oxygen, at temperatures in the range of 250-550°C. The core effect of this is selective fragmentation of EVA chains into lower-molecular-weight hydrocarbons (oil) and carbon-containing solid (char), achieved with significantly lower energy requirement than virgin polymerization.

[0143] The process begins with mechanically recycled EVA granulate that is reduced prior to pyrolysis to particle size of 1-45 mm. If desired, this granulate is subsequently dried to moisture content below 0.5 wt.%. These preparation steps optimize the reactor dynamics by ensuring uniform heating behaviour and preventing hydrolysis reactions, resulting in higher oil yields. The temperature window of 250-550°C is critical: below 250°C insufficient polymer degradation occurs, while above 550°C excessive evaporation and charring lead to loweryields.

[0144] The reactor choice — batch, continuous or semi-continuous operated as drum, screw, auger, tubular orfluidized-bed reactor — offers flexibility and scalability, adaptable to different input qualities and production objectives. Within this reactor, the EVA granulate must reside in the hot zone for 5-120 minutes, which ensures sufficient reaction time for complete conversion without secondary polymerization or excessive cracking. These parameters stabilize at typical yields of 50-85 wt.% oil and 4-12 wt.% char, which mass balance demonstrates technical- economic efficiency and reproducibility; the residual fraction (non-condensable gases) is captured separately and can be used as energy source or discharged.

[0145] The formed pyrolysis gases are condensed in at least two successive condenser stages. This cascade evaporation system ensures separate capture of a light oil fraction and a heavy / waxy oil fraction, while a solid carbon-containing residue fraction (char) is collected separately. After pyrolysis, complete valorisation is achieved: the light oil fraction can serve directly as raw material for polymers, adhesives and chemical products, while the heavy / waxy fraction is further optimized via dewaxing, mild hydro-upgrading and / or distillation. During pyrolysis, additives, fillers and textile components are integrally co-decomposed, and metals and mineral contaminants are mechanically separated beforehand. This multi-component dismantling advantage results in cost savings because previous separation steps can be avoided. Concrete batch validation — for example 5.98 kg EVA granulate processed at 378°C resulting in 4.4 kg oil (of which 1 .4 kg light and 3.0 kg heavy / waxy) and 0.4 kg char — demonstrates reproducible results and mass balance stability within the process window.

[0146] To carry out this method, an integrated installation is required. This comprises first a mechanical pretreatment line, configured for reducing, de-ironing and conditioning EVA footwear waste into granulate. Additionally, the system contains a pyrolysis reactorwith precise temperature control for practical operating conditions of 340-420°C (optimal within the theoretical window of 250-550°C) and an inert gas circuit that ensures the absence of oxygen. Subsequently, a condensation train is necessary with at least two condensers connected in series, which separately capture the light and the heavy / waxy oil fraction. Finally, means are required for the collection of char and for discharging or utilizing non-condensable gases. This architecture realizes multiple processing steps in one integrated system without intermediate cooling or reheating.

[0147] The pyrolysis oil obtained via this method consists of a light fraction and a heavy / waxy fraction, separately captured in successive condenser stages. These products are characterized by traceable composition and reproducible origin, recorded in the process parameters, which enables complete chain traceability. Likewise, char is obtained via the same method — a solid, carbon-containing residue fraction with its own valorisation potential.

[0148] The oil fractions obtained accordingto this method — both light and heavy / waxy — are deployed as circular hydrocarbon raw material to replace virgin raw materials. Specific application areas include production of polymers, plasticizers and adhesives. This achieves demonstrable environmental benefit and circular value proposition through direct substitution of fossil inputs.

[0149] The invention is naturally not limited to the described preferred embodiments, but extends to every embodiment that falls within the scope of protection, as defined in the claims and viewed in the light of the preceding description.

Claims

CLAIMS1 . Method for manufacturing raw materials for the production of shoes, wherein the raw materials are derived from batches of recycled shoes, comprising the following steps: step 1) selecting a process for recycling shoes and / or shoe parts, wherein the process is arranged to process shoes and / or shoe parts into at least fractions of foam, rubber, textile, leather and a remaining fraction of fibers with adhesive (fluff); step 2) separately processing each batch of shoes by means of the selected process from step 1) into fractions of foam, rubber, textile, leather; wherein the method comprises an intermediate step 1 a) between step 1 ) and step 2): step 1a) sorting the shoes to be recycled by shoe type and / or brand into different batches. wherein in step 1) the process yields fractions of foam, rubber, textile, leather, each with a high purity or homogeneity of at least 80%, in particular 95%, characterized in that the method comprises the further steps: step 3) extruding the foam or rubber fraction from step 2) in an extruder into a ribbon; step 4) allowing the ribbon to cool; step 5) pelletizing the ribbon into pellets;2. Method according to claim 1 , wherein in step 3) the temperature of the foam fraction is between 130 and 260°C and the foam fraction is under a pressure of 20-75 bar.

3. Method accordingto claim 1 or 2, wherein the method comprises an intermediate step 2a) between step 2) and step 3): step 2a) pulverizing the foam fraction.

4. Method accordingto claim 1 , 2 or 3, wherein in step 3) during extrusion unused or new foam is added to the extruder in a predetermined ratio.

5. Method accordingto claim 1 , wherein the method comprises the further steps: step 6) extruding the rubber fraction from step 2) in an extruder into a rubber ribbon, wherein the temperature of the rubber fraction is between 130 and 260°C and the rubber fraction is under a pressure of 150-300 bar, such that the rubber fraction devulcanizes during extrusion; step 7) allowing the rubber ribbon to cool; step 8) pelletizing the rubber ribbon into rubber pellets;6. Method accordingto claim 5, wherein in step 6) during extrusion unused or new rubber is added to the extruder in a predetermined ratio.

7. Method according to any one of the preceding claims, wherein step 5) comprises the additional step: step 5a) granulating the pellets obtained from step 5) to a granule size of 1-45 mm.

8. Method accordingto claim 7, wherein step 5) comprises the additional step: step 5b) drying the granules obtained from step 5a) to a moisture content of 0.1 to 0.5 weight percent.

7. Method accordingto anyone of the preceding claims, wherein the method comprises the further step: step 9) continuously or batchwise pyrolyzing the pellets or granules in an inert atmosphere in a pyrolysis reactor, wherein the pellets or granules are thermally decomposed into separate streams of solids (char), liquids and gases.

8. Method accordingto claim 7, wherein the method comprises the further steps: step 10) condensing the (pyrolysis) gases obtained in step 9) by means of one or more condensers into different oil fractions.

9. Method according to claim 8, wherein light oil fraction is recycled as raw material for the production of shoes, such as foam or rubber.

10. Method accordingto claim 7, wherein the solid is used as filler in polymers, pigment carrier or as adsorbent after activation in a raw material for the production of shoes.11 . Method according to any one of the preceding claims, wherein the foam comprises ethylene-vinyl acetate (EVA).

12. Apparatus for manufacturing raw materials for the production of shoes, wherein the raw materials are derived from batches of recycled shoes, comprising:a recycling system arranged for processing shoes and / or shoe parts into at least fractions of foam, rubber, textile, leather and a remaining fraction of fibers with adhesive (fluff); sorting means arranged for sorting shoes to be recycled by shoe type and / or brand into different batches; extrusion means arranged for extruding the foam or rubber fraction into a ribbon; cooling means arranged for cooling the ribbon; palletisation means arranged for pelletizing the ribbon into pellets; wherein the recycling system is arranged to produce fractions with a purity or homogeneity of at least 80%, in particular 95%.

13. Apparatus according to claim 12, wherein the extrusion means are arranged for extruding the foam fraction at a temperature between 130 and 260°C and under a pressure of 20-75 bar.

14. Apparatus accordingto claim 12 or 13, further comprising: pulverization means positioned between the recycling system and the extrusion means arranged for pulverizing the foam fraction.

15. Apparatus accordingto claim 12, 13 or 14, wherein the extrusion means are provided with feed means that are arranged for adding unused or new foam to the extrusion means in a predetermined ratio.

16. Apparatus accordingto claim 12, wherein: the extrusion means are arranged for extruding the rubber fraction into a rubber ribbon at a temperature between 130 and 260°C and under a pressure of 150-300 bar, such that the rubber fraction devulcanizes during extrusion; the cooling means are arranged for coolingthe rubber ribbon; and the pelletization means arranged for pelletizing the rubber ribbon into rubber pellets.

17. Apparatus according to claim 16, wherein the feed means are arranged for adding unused or new rubber to the extrusion means in a predetermined ratio.

18. Apparatus accordingto any one of claims 12 to 17, further comprising: granulation means that are arranged for granulating the pellets to a granule size of 1-45 mm.

19. Apparatus according to claim 18, further comprising: drying means that are arranged for drying the granules to a moisture content of 0.1 to 0.5 weight percent.

20. Apparatus according to any one of claims 12 to 19, further comprising: a pyrolysis reactor arranged for continuously or batchwise pyrolyzing the pellets or granules in an inert atmosphere, wherein the pyrolysis reactor is provided with: an outlet for solids (char); an outlet for liquids; and an outlet for gases.21 . Apparatus accordingto claim 20, further comprising: one or more condensers in connection with the outlet for gases, arranged for condensing pyrolysis gases into different oil fractions.

22. Apparatus accordingto claim 21 , further comprising: recycle means arranged for recycling light oil fraction as raw material for the production of shoes.

23. Apparatus accordingto claim 20, further comprising: processing means arranged for processing the solid as filler in polymers, pigment carrier or as adsorbent after activation in a raw material for the production of shoes.

24. Apparatus according to any one of claims 12 to 23, wherein the recycling system is arranged for processing shoes comprising ethylene-vinyl acetate (EVA) foam.

25. Raw material for the production of shoes obtained according to the method according to any one of claims 1-11.

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