Process for recycling materials from automobile decoration part waste

Abstract

A process for recovering material from automotive trim component waste having at least a double layer comprising a thermoplastic elastomer composite layer and a fibrous layer wherein the fibers of the fibrous layer are interwoven with adjacent thermoplastic elastomer layers.

Description

Technical Field

[0001] The invention relates to a process for recovering materials from automobile trim waste comprising at least one double layer consisting of a thermoplastic elastomer composite material layer and a fiber layer. Background Art

[0002] The automotive industry needs to become more sustainable by increasing the use of recycled raw materials and by reducing waste going to landfill.

[0003] Noise attenuating trim parts with multiple layers comprising different kinds of materials are well known in the automotive industry. In such parts, fiber layers can often be combined with thermoplastic elastomer layers to optimize acoustic or mechanical properties. The layers are usually laminated together so that the respective materials are interwoven, making it difficult to separate the layers for recycling purposes. One of such product groups comprises or consists of a combination of a thermoplastic elastomer layer (e.g., consisting of a thermoplastic elastomer polyolefin (TPO) based composite material) and a fiber layer, wherein the fibers of the fiber layer are at least partially interwoven with the thermoplastic elastomer layer. The elastomeric material penetrates the fiber layer and at least partially surrounds the fiber material. These types of double layers are used, for example, as wear-resistant floor surfaces in trucks and vans, or as intermediate double layers in acoustic components for sound insulation.

[0004] The thermoplastic elastomer layer may be a mixed composition. It may contain an inert filler material, and the thermoplastic component may be a combination of one or more thermoplastic materials including polyester and / or polyolefin-based materials.

[0005] For example, EP3812151 discloses a noise attenuation trim component for a vehicle, comprising a suede layer, a bonding mass layer and a backing layer, wherein the bonding mass layer is bonded to adjacent layers. The bonding mass layer comprises a thermoplastic elastomer polyolefin-based composite material (TPO) having a filler content of at least 55%. Such a bonding mass layer may typically have a density of 1.4 to 1.75 kg / dm 3 Density between and up to 3kg / m 2 The function of the bonding quality layer is to interlock with the pile layer, thereby bonding the fibers and / or filaments and / or tufts within the pile. Good fiber bonding of the pile layer requires good interlocking; however, a high degree of interlocking prevents easy separation of the layers for recycling.

[0006] Floor coverings used in the automotive industry and known as TPO coverings may include one or more layers comprising a thermoplastic elastomer polyolefin (TPO) composite material, which are combined to form a scratch-resistant and durable surface layer, which may also be colored and / or patterned to improve the visual appearance. Such surface layers may be combined with a heavier backing layer, which is comparable to the above-mentioned bonding quality layer, i.e., includes a high content of fillers. The surface layer (possibly combined with a heavier backing layer) may be produced directly on a textile or nonwoven carrier layer.

[0007] Production waste from components containing such dual-layer materials (e.g., resulting from defective components, cutting waste, and coil end material) cannot be separated into the individual original layers, which creates a problem for production waste management. Such waste cannot be recycled back into the production process and is not beneficial to other known recycling or recovery processes. In addition, the high inert filler content of the backing layer (greater than 55% by weight, but typically up to 85% by weight) can give the material a low incineration value. Therefore, they usually end up in landfills.

[0008] The most common technologies currently known and used for recycling production waste from parts including the above-mentioned type of double layer focus on size reduction and include knife grinding / grinding, cutting and shredding, with the aim of reducing the size of production waste into small fragments that can be integrated into other types of layers as filler contents. However, the product obtained in this way has no added value. In a known process, the material is shredded to obtain tiny particles, which are then spread between two outer nonwoven layers. The interlayer thus obtained is then needle-punched and can be used to produce automotive decorative parts, such as floor parts or wheel cover outer lining structures. However, the disadvantage of this process is that only a small amount of recycled materials can be integrated back into the automotive decorative parts, and in addition, the shredded tiny particles may cause technical problems, such as broken needles during needle punching. However, the biggest disadvantage of this recycling process is that the high-quality materials (e.g., polyester fibers) included in the fiber layer may be mixed with low-value materials, thereby reducing the value.

[0009] There are also methods that are intended to separate carpet products, but these methods are targeted at products that have a thin adhesive layer rather than a thick thermoplastic layer.

[0010] The waste contains low levels of high-quality materials such as polyester, which has hampered efforts by established recycling companies to chemically separate the materials to create value-added waste streams.

[0011] As far as we know, there is no process on the market that can successfully separate the fiber material forming the double layer from the thermoplastic elastomer polyolefin-based composite (TPO) and reuse the fiber material and / or the thermoplastic material of the elastomer layer.

[0012] Therefore, the object of the present invention is to provide a method for recycling waste material, which waste material comprises a plurality of material combinations, including a double layer consisting of a thermoplastic elastomer material layer and a fiber layer, which are interwoven with each other during the production process, as previously described. Summary of the invention

[0013] According to the independent claim and the claims dependent therefrom, this object is achieved by a method for recycling material waste from an automotive trim component comprising at least a double layer consisting of a layer of thermoplastic elastomer composite material and a fiber layer.

[0014] In particular, a process for recycling material waste from an automobile trim component, the automobile trim component comprising at least a double layer consisting of a thermoplastic elastomer composite material layer and a fiber layer, wherein the fiber layer and the adjacent thermoplastic elastomer layer are interwoven with each other, the method comprising:

[0015] Step 1 provides a raw material consisting of waste from an automobile decorative part, wherein the automobile decorative part comprises a double layer consisting of a thermoplastic elastomer compound TEC material layer and a fiber layer, wherein the layers are interwoven with each other;

[0016] Step 2: forming a feedstock F' by reducing the feedstock provided in step 1 into pieces all having approximately the same size, the size of which is between 5 and 60 mm, preferably between 10 and 30 mm, more preferably between 10 and 15 mm, measured at the largest cross section parallel to the plane of the layer;

[0017] Step 3: Feeding the raw material F' into a rotary hammer mill, wherein the hammer head rotates along at least one perforated screen throughout the rotation of the hammer, the perforated screen being arranged at a certain distance from the end of the hammer head, and wherein the action of the hammer causes the thermoplastic elastomer composite (TEC) to be broken up, separated from the fibrous material, and further reduced in size into particles filtered through the perforated screen, thereby forming a first material portion consisting essentially of TEC (hereinafter referred to as "TEC material portion"), while the remaining fibrous material remains in the grinding chamber and forms a second material portion X, wherein the fiber size in portion X is not significantly reduced;

[0018] Step 4 removes the fiber portion X from the grinding chamber.

[0019] Surprisingly, by using a hammer mill, a thermoplastic elastomer composite (TEC) material can be separated from a fiber layer, and the TEC material thus obtained is clean enough to be fed back into the TEC production step. At the same time, the fiber portion can also be used again. Due to the use of a hammer mill as a size reduction and separation unit, the initial length of the fiber can be substantially maintained, which is limited by the initial fragment size. The fiber portion thus obtained can be used as a fiber material in a low-quality nonwoven material, and the fiber material in the low-quality nonwoven material is mixed with other fiber materials preferably from a recycled source. However, as the concentration of high-value materials increases, this material has also attracted the interest of standard recycling methods or incineration of external recycling companies. For example, short fiber portions can be used as fillers in composite materials for non-automotive applications (such as building materials).

[0020] Surprisingly, the impact of the decorative waste fragments forming feedstock F' against the walls and hammers of the hammer mill causes frictional stresses within the double layer. Since the TEC material is not firmly bonded to the fiber material, the TEC material will break up and "bounce" off the fibers. Although the fibers will become less limited by the loss of TEC bonding, they are softer and resist any further breakage in the first place. They may be slightly chopped or chipped, but will remain substantially intact for most of the process.

[0021] By adjusting the residence time during the hammer milling step, the process can be further optimized by selecting the residence time so that a good separation can be obtained without significantly reducing the fiber length. The fibers will be entangled into loose fiber groups and can be removed from the hammer mill chamber individually or via continuous or discontinuous process steps. Preferably, an opening can be integrated into the hammer mill so that the fiber material can be regularly purged from the chamber, preferably using the centrifugal force already present and the air flow generated by the rotation of the hammers. The opening can be opened at intervals before reloading the grinding chamber.

[0022] The fibrous material obtained in fraction X can be used in standard recycling processes dedicated to fibrous materials and / or as filler in automotive or non-automotive applications.

[0023] The thermoplastic elastomer composite layer can be a mixed composition. It can contain an inert filler material, and the thermoplastic component can be a combination of one or more thermoplastic materials (including polyester and / or polyolefin-based materials). Preferably, the thermoplastic elastomer layer is a thermoplastic elastomer polyolefin-based layer (TPO layer) and includes a thermoplastic elastomer polyolefin (TPO) as a basic composite forming the bulk of the material, or as the main matrix component in the case of a filled layer or a highly filled layer.

[0024] For example, the floor surface layer may be based on a polypropylene thermoplastic elastomer layer (PP-TPO) extruded on top of a fibrous backing layer or compressed together with the fibrous backing layer.

[0025] The thermoplastic elastomer composite layer (TEC) may be a highly filled TEC layer comprising up to 90% by weight of filler and is molded together with at least one fiber layer to form a mass layer for an acoustic trim component.

[0026] In case the trim part comprises additional layers, such as foam layers, these layers can be separated from the two-layer structure in advance, or the trim part waste including the foam layer can be reduced in size in step 1. An optional step can be introduced, in which, before step 2, the shredded material is separated in a cyclone separator to eliminate the foam part.

[0027] The two fractions recovered from the hammer mill - TEC and X can undergo another separation process, preferably a screening process, to eliminate small fibrous materials. The dust generated during hammer milling can be collected together with the TEC fraction.

[0028] All TEC fractions recovered from the hammer mill and / or from the optional subsequent screening step may be subjected to a melt filtration step to eliminate any remaining debris and to pelletize the final TEC fraction.

[0029] The recycled TEC fraction can be fed into a TEC extrusion process, optionally combined with virgin and / or other sourced TEC material, and produce a TEC layer. This can again be combined with a fiber layer to form a dual layer structure. Preferably, the recycled TEC fraction can account for up to 30% by weight of the total TEC extrudate.

[0030] The fiber fraction can be incinerated or integrated into fiber layers, composite layers or interlayers for the production of automotive trim parts.

[0031] The TEC layer comprising recycled TEC and the fiber layer, composite layer or intermediate layer comprising recycled fibers can be reused in automotive trim parts.

[0032] As used herein, a thermoplastic elastomer composite layer (TEC), preferably a polyolefin-based composite (TPO) layer, is a layer based primarily on a thermoplastic elastomer material. This layer can be used as a decorative surface covering or film and can be combined with a fibrous nonwoven layer on the back to enable bonding to an additional layer. The combination of a TEC surface layer with a fibrous backing layer forms a two-layer structure for automotive floors or covering parts, such as floor panels, cladding or side trims.

[0033] Such a TEC surface layer may comprise, for example, an elastomeric composition comprising a very low density ethylene polymer component and / or a propylene polymer component. It may further comprise additives and color dyes to obtain a more or less glossy appearance and to obtain a decorative pattern or color. In addition, the layer may be embossed to form a decorative surface. The TEC surface layer may comprise more than one layer, wherein at least the main layer is a thermoplastic elastomer composite (TEC) layer, to which a sacrificial top surface layer or sacrificial top surface coating also based on polyolefin may be applied. The TEC surface layer is preferably a PP or PE elastomer TPO layer.

[0034] Alternatively, the thermoplastic elastomer composite (TEC) can be used as a backing weight layer or bonding mass layer in an insulating trim part in an automobile. The TEC-based material can be a thermoplastic elastomer polyolefin-based composite (TEC) with a filler content of at least 55%. Such layers can typically have a weight of 1.4 to 1.75 kg / dm 3 Density between and up to 3kg / m 2 The polyolefin may be a polymer based on polypropylene or polyethylene.

[0035] The fiber layer can be a fiber nonwoven used as a decorative covering layer for a decorative part, or can be used as a carrier layer during the production of the mass layer / backing layer itself. The fiber layer can be a nonwoven or coarse cloth layer based on short fibers or endless filaments. Preferably, short fibers with an average length between 10 and 60 mm, preferably between 20 and 35 mm, are used. The fiber layer can include any fiber or fiber mixture based on artificial fibers or natural fibers. Preferably, the fiber is based on a polymer or copolymer of polyester, polyamide or polyolefin or polylactic acid, or based on animal fibers (such as wool), or based on plant fibers (such as cotton, hemp, flax) or the like. Preferably, the fiber layer is based on polyester, preferably based on polyester terephthalate.

[0036] The TEC layer may be a combination of multiple TEC layers. In this structure, at least one of the TEC layers is interwoven with the fiber layer forming a double-layer structure. In a specific embodiment, at least one of the TEC layers may include a filler material. However, in the recycling process, the multi-layer TEC structure can be completely processed without separating the TEC layers.

[0037] As used herein, a "thermoplastic elastomer composite (TEC) layer interwoven with a fiber layer" means that the fibers of the fiber layer are at least partially surrounded by the thermoplastic elastomer composite (TEC) material, so that it is no longer possible to separate the two materials without destroying the structure of the layer. In most cases, it is not even possible to see the double layer structure. Therefore, the double layer may be considered as one layer.

[0038] A raw material of scraps of a double-layer waste material is provided, the double-layer waste material comprising at least one thermoplastic elastomer composite (TEC) layer interlaced with a fiber layer. The double-layer waste material comes from the production of automotive trim parts (such as floor parts, coverings or panels) and comprises at least a double layer consisting of a TEC layer interlaced with a fiber layer. The interlacing is related to the process of producing such a layered material, where the TEC is directly extruded on top of a fiber carrier layer or a thermoforming process compresses these layers together, forming a double-layer material that is no longer separable into single layers.

[0039] The double layer material for the raw material can be cutting waste, cutouts, defective parts or coil end materials, and scrapped automotive decorative parts in the production of automotive decorative parts, which include a double layer consisting of a thermoplastic elastomer composite (TEC) layer and a fiber layer. The double layer can be used and produced as such, or it can be combined with an easily separable layer, such as a foam layer laminated thereon. The process can include a pre-separation step to remove any other layers from the double layer, such as a scraping or splitting step with a blade.

[0040] For example, the double layer forming the waste raw material may consist of a TPO decorative surface layer for covering the surface of a car or truck and a fiber backing layer, wherein the fiber layer is interwoven with the TPO decorative surface layer at least on the back side of the TPO layer. The TPO layer may be a single layer or a combination of multiple layers.

[0041] Another example of a double layer forming a waste feedstock may be a fibrous surface layer (e.g. a nonwoven layer or a needle punched carpet layer) with a thermoplastic elastomer polyolefin composite (TPO) backing layer, also called a mass layer or heavy layer. This layer may contain up to 95% filler by weight.

[0042] Typically, the TEC layer can be a film or a foil.

[0043] The TEC layer may be foamed in an injection foaming process (eg with polyurethane type foam).

[0044] The TEC layer can be sandwiched between two fiber layers forming a tri-layer that can be processed like a bi-layer material.

[0045] The fibrous nonwoven material may comprise a staple fiber or endless filament nonwoven material based on natural and / or synthetic fibers or fiber blends, which synthetic fibers or fiber blends preferably comprise polyesters, preferably polyethylene terephthalate (PET), polyolefins, such as polypropylene or polyethylene, or polyamides, such as polyamide-6 or polyamide 6-6.

[0046] The double layer waste material preferably does not contain polyvinyl chloride PVC and / or latex, such as styrene-butadiene resin (SBR).

[0047] In principle, any TEC layer combined with a fiber layer forming waste from the automotive industry can be used as feedstock for the current process. In principle, clean waste generated before the trim part is used in a car can be used without treatment, while scrap material can be used after preferably surface cleaning to reduce any dirt or grease that might interfere with the final part reuse.

[0048] Preferably, the waste material from the production of automotive trim parts or from scrapped parts can be cut into pieces of smaller size (as defined by the inlet of the machine used in the method according to the invention). Optionally, additional layers (such as foam layers, preferably polyurethane foam layers) can be separated before, for example by a splitting or scraping process. Small amounts of additional layers may still be present on the waste raw material used for the recycling process according to the invention without reducing the effectiveness of the method itself.

[0049] The waste feedstock is shredded or cut into pieces, all of which have approximately the same size, which is between 5 and 60 mm, preferably between 10 and 30 mm, and more preferably between 10 and 15 mm. This shredding or cutting operation is preferably done with minimal shearing of the waste feedstock to prevent any powder formation and / or fiber breakage to a size smaller than the cut size and / or plastic deformation of the TEC material.

[0050] This shredding can be done directly before the next step of the method according to the invention, or can be carried out separately in time and / or space. In particular, it may be advantageous to already perform this shredding at the production site of the automotive trim parts, thereby minimizing the space required for storage and transportation of the scrap raw material fragments.

[0051] The waste material can be shredded or cut into small pieces with conventional grinders, shredders or cutters known in the art. In this step, the waste material is only reduced in size, preferably without substantially generating dust. As an alternative to pre-separation, an additional layer (such as a foam layer) can be reduced together with the double layer into smaller pieces, and in the same step, a cyclone separator or any other technology capable of separating light and heavy weight material fragments can be used to separate them. The portion containing the double layer material comminuted into substantially equal size fragments forms the feedstock F' for the second process step.

[0052] The shredded feedstock F' is fed into a rotary hammer mill, wherein the hammers rotate along at least one perforated screen throughout the hammer rotation, the perforated screen being arranged at a distance from the ends of the hammers, and wherein the action of the hammers causes the thermoplastic elastomer composite (TEC) to be broken up and separated from the fibrous material and further reduced in size into particles that are filtered through the perforated screen or grid, thereby forming a first material portion consisting essentially of TEC, while the remaining fibrous material remains in the grinding chamber and forms a second material portion X, wherein the size of the fibers in portion X has not been significantly reduced in size throughout the process. Depending on the perforations in the screen, the TEC portion can be further divided into a plurality of material portions consisting essentially of TEC-based material. In a first region of the curved wall of the hammer mill, just before the perforated screen, an intense breaking zone can be created with bars or blades, which enables greater impact of the flying fragments / particles with the wall. Preferably, the system is arranged so that the shearing energy is not sufficient to melt the TEC-based material.

[0053] In an additional step, or in conjunction with the previous step, the fiber material is removed from the grinding chamber.

[0054] The hammers in the hammer mill are preferably blade-shaped with blunt edges. A plurality of blades may be arranged on a rotating shaft so that the ends of the hammers pass along the curved hammer mill wall at equal distances or at distances decreasing in the direction of rotation so that smaller particles cannot accumulate in layers between the perforated screen and the hammers and reduce the efficiency of the hammer mill. The outer blades at the beginning or end of the shaft (one side of the blades is directly opposite the side walls of the grinding chamber) may be shaped to prevent the formation of material lumps on these wall sides.

[0055] During the rotation of the hammers, the waste material is picked up at the inlet and conveyed around. The fiber portion will remain in the grinding chamber until manually removed, or can be conveyed to a fiber outlet located after the perforated screen area, preferably just before the inlet area of ​​the material (when related to the direction of rotation of the hammers). Removal can be assisted by guide plates and can benefit from the centrifugal force on the fiber material obtained by the action of the hammers. The fibers can be removed continuously or intermittently via the fiber outlet. Airflow can help remove the fiber material from the grinding chamber containing the hammers.

[0056] After the hammer mill process step, at least two main material fractions are obtained: a TEC fraction and an X fraction. The TEC fraction mainly comprises TEC-based materials in the form of granules or powder. This fraction can be directly reused in the TEC-based material process or can be further cleaned in a melt filtration step and then used in the TEC-based production process.

[0057] At least part of the TEC can be reused in the process from which the material was sourced. This could be, for example, the production of TEC flooring, or the production of a mass layer or backing layer. In particular, in the production of a mass layer or backing layer, it can be demonstrated that the recycled TEC part can be used as a filler part without reducing the quality of the product or compromising the overall characteristics of the decorative part produced therefrom. In contrast, the recycled material is not noticeable in the product or its properties.

[0058] In a second method step, the fiber fraction can be screened, for example in a cyclone separator, to obtain a further separation of the fiber material and any material that has not yet been completely separated. The latter material can be sent back to the hammer mill for further separation.

[0059] An example of a recycling method according to the invention.

[0060] During the production of floor parts for vehicles including double layers, waste in the form of cutting waste, offcuts, coil end materials and discarded parts is collected and cut into chips of about 15 to 30 mm to form waste raw material F. The material is fed into a hammer mill having a plurality of rotating hammer blades having blunt edges and ends.

[0061] The laboratory hammer mill was fed with raw materials in batches, with the residence time kept constant.

[0062] From 1 kg of the initial mixed TPO / fiber waste material containing 78% TEC material, 82% of the TEC material as a separate fraction can be recovered. This is already a high yield, considering that the process has not yet been fully optimized. In particular, further increases in the yield can be expected by further adjusting the hammer mill settings, such as speed, distance between the end of the wall and the shape and size of the hammers. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 A and Figure 1 B shows a cross section of an automotive trim component comprising at least two layers.

[0064] Figure 2 A flowchart showing the main method according to the present invention is shown

[0065] Figure 3 A flow chart showing the main method including optional further cleaning steps is shown.

[0066] Figure 4 A schematic cross section of a rotary hammer mill is shown. DETAILED DESCRIPTION

[0067] Figure 1Examples of 2 different layouts of an automotive trim component structure comprising a double layer are shown. Depending on the function of the TEC layer and the fiber layer, the double layer can be visible from one side of the passenger compartment or can be hidden in the trim component.

[0068] More generally, the fiber layer can have different functions in the automotive trim component, such as a carpet-type surface layer (such as Figure 1 B), airflow resistance layer, isolation layer, or technical functions such as preventing the TEC layer from sticking or increasing the mechanical properties of the layer (such as Figure 1 A).

[0069] Figure 1 A shows a cross section of a TPO floor 10 for motor vehicles with a large load floor area, particularly trucks or SUV type vehicles. Such TPO floors are typically made of polypropylene-based TPO materials with zero or low filler content. The TPO floor 10 includes a double-layer structure consisting of a thermoplastic elastomer layer 20 and a fiber backing layer 30. For such applications, the thermoplastic elastomer layer 20 is typically made of polypropylene-based TPO materials with zero or low filler content. The surface of the TPO layer 20 is embossed to obtain a decorative and non-slip floor surface. The fiber backing layer and the TPO surface layer are interwoven with each other, making it no longer possible to separate them without destroying these layers. The TPO material penetrates between the fibers and at least partially surrounds the fibers of the fiber layer.

[0070] The TPO material used for the surface is preferably based on a composite material comprising a polyolefin elastomeric resin, a filler such as CaCO3 and optionally other polyethylene or polypropylene based resins, low density polyethylene LDPE, linear low density polyethylene LLDPE or high density polyethylene HDPE.

[0071] The fibrous nonwoven material may comprise a staple or endless filament nonwoven material based on synthetic fibers or fiber blends, which preferably comprise polyesters, preferably polyethylene terephthalate (PET), polyolefins, such as polypropylene or polyethylene, or polyamides, such as polyamide-6 or polyamide 6-6.

[0072] Alternatively or additionally, the fibrous layer may comprise natural fibers, such as wool, hemp, cotton, linen or any other fibrous material of natural origin.

[0073] The staple fiber may include a mixture of different fiber materials and / or it may contain recovered or recycled fibers.

[0074] In addition, the fiber layer may include a binder, for example in the form of binder fibers or in the form of a powder based on the same or similar materials as those mentioned for the staple fibers. Preferably, the binder is compatible with the selected staple fibers so that mixed recycling does not cause problems. For example, a polyester-based fiber material has staple fibers and a binder based on polyester, preferably on terephthalate.

[0075] The fibrous layer may also be a spunbond nonwoven layer of endless filaments, preferably of terephthalate-based polyester.

[0076] Figure 1 B shows a three-layer structure commonly used for sound attenuation, where the TPO base layer 40 forms the mass layer and the soft foam layer 60 forms the spring layer. Together, these two layers act as an acoustic mass spring system that acts as a sound barrier when placed in a vehicle interior. The surface layer can be a simple nonwoven layer 50 or a needle punched nonwoven carpet layer. The TPO base layer can be extruded onto the fiber layer, thereby at least partially surrounding the fiber layer, forming a double layer structure that can no longer be separated into a single layer.

[0077] The materials used for the two-layer construction are in principle comparable to those listed above for floor construction. The actual polyolefin resin used, as well as the filler content, may differ. The mass layer function is associated with high-density materials, so higher filler contents can be achieved for these TPO-type layers. It is known to use these TPO base weight layers or mass layers between other layers to form an airtight barrier with a high area weight. In order to achieve this with a minimum thickness, highly filled materials are used. Therefore, a typical TPO base weight layer material comprises 70-95% by weight of an inert filler material, such as CaCO3 and a thermoplastic elastomer matrix.

[0078] according to Figure 1 The fiber layer in the alternative acoustic layout of B may be a fleece layer comprising fibers and / or filaments and / or yarns. The layer may be made of at least one polymer or copolymer selected from the group consisting of polyesters, preferably terephthalate-based, such as polyethylene terephthalate (PET), or polyamides, preferably polyamide-6 (PA6) or polyamide-66 (PA66), or polyolefins, preferably polypropylene (PP) or polyethylene (PE), or a mixture of two or more of these polymers and / or copolymers. The fibers, filaments and / or yarns may be based on bio-resourced, recycled or recycle materials, or may include materials of this type of origin.

[0079] Generally, the fiber layer can be any fiber layer, such as a nonwoven fiber layer or a scrim layer, and can have a fiber density of 100 to 1500 g / m 2The fiber layer may include solid fibers, hollow fibers, bonded fibers, or bicomponent fibers, and a small percentage of non-fibrous material, such as foam chips or waste.

[0080] Alternatively, a foam layer, preferably a polyurethane foam layer can be used as a backing layer. The foam layer can be laminated to a double-layer structure, or applied in a reaction injection foaming process, wherein the foam layer foams directly on the surface of the bonding quality layer. A coarse cloth can be placed between them so that the bonding quality layer can be molded, and increase the bonding force between the layers. Alternatively, a soft fiber layer can be laminated on the double layer, and these softer layers are not intended to be surrounded by the TPO base layer, and can only be laminated to the contact surface after the double-layer structure is produced. Therefore, these types of layers can be sheared or pulled down from the double-layer structure, leaving only a small amount of fiber.

[0081] like Figure 1 The floor shown in A and Figure 1 The three-layer structure shown in B can be used to produce automotive trim parts. To produce such parts, the two-layer structure or the three-layer structure can be combined with additional layers and formed to produce the shape required for the part to fit in the dedicated space of the vehicle. They can be used as such or even combined as floor and / or inner dashboard and / or surface coverings in the main passenger compartment, and / or as floor and / or side coverings in the luggage area, and / or as cladding, paneling.

[0082] Figure 1 A and Figure 1 Both product groups in B belong to automotive trim parts which form part of a production and waste cycle as depicted in the following process flow diagram.

[0083] According to the present invention, the cutting waste, excisions, discarded parts and / or scrapped parts of automotive trim parts are considered as waste W, which can be used to feed a recycling or recovery process. For the process according to the present invention, the double layer structure is the core of the recovery process, while any additional layers are optional.

[0084] Any additional layers can be substantially eliminated through a pre-separation process to discard these layers individually. This is more advantageous because the layers retain their base material and are not further mixed with other materials.

[0085] Figure 2 The main method according to the invention is shown in a first embodiment. The raw material F is supplied by a waste stream W from the production of automotive trim parts ATP. The main components of the waste stream consist of cutting waste, cut-outs, defective parts and web end material, which comprises at least a double layer consisting of a thermoplastic elastomer-based composite material and a fiber layer, such as, for example Figure 1The fiber layer and the TEC layer are interwoven with each other so that the two layers cannot be separated without damaging the two layers.

[0086] The defined automotive trim parts waste is reduced in size to cover the limitations of subsequent machines and treatments and forms a raw material F for a recycling process. The raw material F is fed into a size reduction machine Sh, such as a shredder, a cutter or similar machine, which is capable of cutting the raw material into small pieces, preferably without significantly reducing the thickness of the double layer and / or significantly changing its properties. In particular, the size reduction process should be such that the raw material is not subjected to considerable heat or ground into a powder. Preferably, a size distribution substantially within a given range is obtained, with a low level of oversized and undersized particles.

[0087] The raw material F' resulting from the shredding process should have an average size preferably between 3 and 60 mm, preferably between 10 and 30 mm, more preferably between 10 and 15 mm. The size of the cut or shredded pieces defines the maximum fiber size that can be achieved in the following steps. In principle, it is desirable to keep the fiber size larger, since high levels or shredding may reduce the efficiency of the recycling process.

[0088] It is beneficial to introduce a size reduction step next to the automotive trim production line so that any discarded larger parts can be reduced in size to optimize storage and transportation. This step can thus be separated from the other steps and the smaller parts can be stored and transported in large bags. However, it may be more economical and environmentally friendly to keep all steps of the recycling close to the actual automotive trim production.

[0089] The raw material F' is fed into the rotary hammer mill RHM. In the rotary hammer mill, the size-reduced fragments are hit by the rotating hammers, whereby the thermoplastic elastomer polyolefin-based composite material is broken and sieved to form a material portion consisting mainly of TPO material, while the fiber material may be entangled without significant size reduction because it is a lighter and softer portion, which remains in the grinding chamber. This ability to entangle with other fibers or to stay in the entangled stage after removing the TPO makes it easy for the fibers to remain in the grinding chamber, and fewer fibers will escape through the provided screen or grid.

[0090] The screen plate in the chamber should be selected so that the fiber material cannot pass through, but the broken TPO fragments / particles can pass through. Optionally, classification can be introduced to distinguish the powder and particle size fractions of TPO. The fiber fraction X can be taken out of the grinding chamber in a continuous or discontinuous manner or in batches, depending on the fiber fraction in the original raw material and the output of the process. The TPO fraction and / or the fiber fraction X can be subjected to a screening step Si to further clean the fiber fraction from the TPO fraction.

[0091] The TPO fraction can be fed back into the automotive trim component ATP production, for example as a filler in a TPO layer. Alternatively, the recycled TPO can be used to produce other components or layers for automotive products, or the recycled TPO can be used outside the automotive product field.

[0092] The method may be enhanced by a number of optional steps to further purify and / or clarify the fractions obtained.

[0093] For example, the TPO fraction obtained can undergo a screening step Si to eliminate any remaining fiber component X, which fiber fraction can be combined with the fraction obtained from the grinding chamber, however depending on the quality of this fraction. The fiber fraction can also undergo a screening step to obtain any pulverized or granular TPO.

[0094] Part of it can be recycled back to the hammer mill for the next cycle.

[0095] Optionally, in order to achieve good processing and transportation, preferably, the obtained TPO fractions (TPO, TPO") are subjected to melt filtration MF to further clean them and granulated to form small particles. Any filtered impurities D can be discarded.

[0096] The granular TPO' thus obtained can be fed into the production of virgin TPO layers or into compatible TPO products. Material cut from this or subsequent processes for making automotive trim parts can be fed again into the waste recycling process indicated by the arrows, making it a closed loop process.

[0097] Surprisingly, it has been found that the melt filtration process under controlled temperature conditions reduces or eliminates possible benzene release during the TPO production process or from the produced TPO layers. Such benzene release is considered a barrier to recycling TPO materials for reuse.

[0098] The recycling process according to the invention is sustainable; no additional materials are introduced and the waste stream destined for landfill can be significantly reduced, preferably to a near zero weight share. In particular, the low-cost inert filler can be fully recovered and reused as filler, while the fiber part is lightweight and can be used in fiber layers for decorative parts or even increase value for incineration.

[0099] flow chart Figure 3 Shown with Figure 2A comparable process is shown in for a decorative part comprising at least three layers of material. As in the other processes, the decorative part comprises at least one double layer comprising a thermoplastic elastomer material and a fiber layer, and additionally, the decorative part comprises an additional layer in the form of a polyurethane PUR foam adjacent to the TPO layer or the fiber layer, for example a rigid or semi-rigid foam layer. The waste from the production of such decorative parts can be subjected to a shredder without prior separation of the foam layers, or a first rough pre-separation can be performed, such as a scraping or splitting method using, for example, a blade (not shown). Alternatively, in particular when the foam is a relatively thin layer, the waste can be immediately reduced to smaller particles without pre-separation. Since the PUR foam is a material with a relatively low cohesive strength, the PUR foam will be cut, delaminated or broken from the double layer under the effect of size reduction, for example in a shredder or cutting device. The inclusion of a cyclone separator after size reduction enables separation of light foam fragments and heavier double layer fragments. The foam portion thus obtained can be fed into a separate foam recycling system known in the art, while smaller amounts of foam can also be fed back into foam production as precursor or foam filler or used in other layers of automotive trim parts.

[0100] Figure 4 A cross section of an example of a hammer mill is shown in more detail. Figure 2 and Figure 3 The raw material is captured by the rotating blades and hits the wall of the grinding chamber, which can also be formed by a grid or screen 6, or by a special impact zone with a rod 8 located on the wall to increase the initial impact. Due to the impact of the particles with the wall, screen or blades, the TEC material is broken and separated from the fibers, which are light and elastic enough to remain in the state of entangled bundles. The TEC part is sheared out of the fiber part X and comminuted. This part will be separated by the grid 6 and leave the grinder as a TPO part, while the fiber part X remains in the grinding chamber and can be released through a separate outlet 7, where the dotted line represents a possible movable outlet door. The retrieval of the fibers from the grinding chamber can be carried out in different ways, this is just an example of, for example, manual retrieval of the fiber part.

[0101] Preferably, all steps are placed on a continuous production line or at least on a single device, but this is not necessary. These steps can be separated in time and / or space. Pre-separation and / or size reduction can be completed near the automotive trim production, while hammer milling and further cleaning can be completed in another (preferably more centralized) facility. Waste can be collected from different places, and the recycled parts can be used again in different places. Although the benefits are less, the fiber part that no longer contains the thermoplastic elastomer part may be more valuable for heat generation and can be used in this way.

Claims

1. A process for recovering material waste from an automobile decorative part, the automobile decorative part comprising at least a double layer consisting of a thermoplastic elastomer composite material layer and a fiber layer, wherein: The fiber layer and the thermoplastic elastomer layer are interwoven with each other, and the process comprises the following steps: - Step 1, providing a raw material F consisting of waste from an automobile trim part, the automobile trim part comprising a double layer consisting of a layer of thermoplastic elastomer composite TEC material and a fiber layer, wherein the layers are interwoven with each other; - step 2 of forming a feedstock F' by reducing the feedstock provided in step 1 into pieces all having substantially the same size, measured at the largest cross section parallel to the layer plane, of between 5 and 60 mm, preferably between 10 and 30 mm, more preferably between 10 and 15 mm; - Step 3, feeding the raw material F' into a rotary hammer mill, wherein the hammer heads rotate along at least one perforated screen throughout the rotation of the hammer heads, the perforated screen being arranged at a distance from the ends of the hammer heads, and wherein the action of the hammers causes the thermoplastic elastomer composite (TEC) to be broken up, separated from the fibrous material, and further reduced in size to particles filtered through the perforated screen, thereby forming a first material fraction consisting essentially of TEC material, while the remaining fibrous material remains in the grinding chamber and forms a second material fraction X, wherein the fiber size in fraction X is not significantly reduced; - Step 4, removing the fiber portion X from the grinding chamber.

2. The process according to claim 1, wherein The raw material in step 1 further includes a foam layer attached to the fiber layer or TEC layer.

3. The process according to claim 2, wherein: The waste material including the foam layer undergoes another separation step, wherein the shredded material resulting from step 1 is passed through a cyclone separator prior to step 2 to eliminate the foam fraction.

4. The process according to claim 1, wherein: The waste raw material F used in step 1 is pre-cut into chips.

5. The process according to claim 1, wherein: The TEC fraction from step 3 is subjected to a separation process, preferably a screening process, to eliminate residual fibrous material.

6. The process according to claim 1, wherein: The TEC fraction from step 3 undergoes a melt filtration step to eliminate any remaining debris and is pelletized.

7. The process according to claim 1, wherein: The TEC material is a thermoplastic elastomer polyolefin, preferably a thermoplastic elastomer polypropylene or a thermoplastic elastomer polyester based material.

8. The process according to claim 1, wherein: The TEC layers are thermoplastic elastomer multilayers, and at least one of the outer TEC layers and the fiber layers are interwoven with each other.

9. The process according to claim 1, wherein: The waste material comprises a dual layer consisting of a thermoplastic elastomeric polyolefin (TPO) aesthetic surface layer and a fibrous backing layer.

10. The process according to claim 7, wherein: The TEC layer is a thermoplastic elastomer multilayer, wherein the first layer is a thermoplastic elastomer polyolefin (TPO) surface layer having a filler content between 0 and 7%, and the second layer is a highly filled thermoplastic elastomer polyolefin (TPO) layer having a filler content of at least 55% and not more than 85%, and wherein at least the second layer is interwoven with the fiber layer.

11. The process according to one of the preceding claims, wherein The TEC layer comprises an inert filler, preferably calcium carbonate.

12. The process according to claim 1, wherein: The recycled TEC fraction is fed into a TEC extrudate and combined with conventional TEC and a TEC layer is produced.

13. The process according to claim 12, wherein: The recovered TEC fraction may constitute at most 30% by weight of the total TEC extrudate.

14. Process according to one of the preceding claims, further comprising, preferably before step 1, pre-separating the bilayer from the additional layer.

15. The process according to one of the preceding claims, wherein The fiber fractions are incinerated or integrated in fiber layers, composite layers or intermediate layers for automotive trim parts or for parts for non-automotive applications.

16. Use of a TEC layer comprising the recycled TEC fraction of claim 12 and / or a fiber layer, composite layer or interlayer of claim 15 comprising said recycled fiber fraction in an automotive trim part.

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