Process for reclaiming material from automotive trim part waste

Abstract

Process for reclaiming material from automotive trim parts waste with at least a bilayer comprising a layer of thermoplastic elastomeric compound material and a fibrous layer whereby the fibers of the fibrous layer are intertwined with the adjacent thermoplastic elastomeric layer.

Description

DescriptionProcess for reclaiming material from automotive trim part waste.Technical Field

[0001] The invention is directed to a process for reclaiming material from automotive trim parts waste comprising at least a bilayer consisting of a thermoplastic elastomeric compound material layer and a fibrous layer.Background Art

[0002] The automotive industry needs to become more sustainable both by increasing utilisation of recycled raw materials as well as by reducing waste destined for landfill.

[0003] Noise attenuating trim parts with multiple layers comprising different kind of materials are well known in the automotive industry. In this kind of parts, fibrous layers may typically be combined with thermoplastic elastomeric layers to optimise acoustic or mechanical performance. Layers are often laminated together so that the respective materials intertwine, making it difficult to separate the layers for recycling purposes. One of such a group of products consists of, or comprises, a combination of a thermoplastic elastomeric layer, e.g. consisting of a thermoplastic elastomeric polyolefin (TPO) based compound material, and a fibrous layer, whereby the fibers of the fibrous layer are intertwined with the thermoplastic elastomeric layer at least partially. The elastomeric material penetrates the fibrous layer and engulfs at least partly the fibrous material. These type of bi-layers are used for instance as hard wearing floor surfaces in trucks and vans, or as an intermediate bilayer in acoustic parts for sound insulation.

[0004] The thermoplastic elastomeric layer may be of mixed content. It may contain inert filling material and the thermoplastic component might be a combination of one or more types of thermoplastic materials, including polyesters and / or polyolefin based materials.

[0005] For example EP3812151 discloses a noise attenuating trim part for a vehicle comprising a pile layer, a bonding mass layer and a backing layer whereby the bonding mass layer is bonded to the adjacent layers. The bonding mass layer is comprising a thermoplastic elastomeric polyolefin based compound material (TPO) with a filler content of at least 55%. Such bonding mass layer may typically have a density of between 1.4 and1 ,75kg / dm3and an area weight of up to 3 kg / m2. The bonding mass layer function is to interlock with the pile layer and thereby bind the fibers and / or filaments and / or the tufts within the pile. A good interlocking is needed for a good fiber binding of the pile layer; however, the high interlocking prevents an easy separation of the layers for recycling.

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

[0007]

[0008] Production waste (generated, e.g., by faulty parts, cut-offs and end-of-roll materials) from parts containing this type of bilayer materials, which cannot be separated into the single original layers, forms a problem for production waste management. This kind of waste cannot be looped back into the production process, and it is also not interesting for other known recycling or reclaiming processes. Furthermore, the high inert filler content of the backing layer, above 55% by weight, but normally reaching up to 85% by weight, may give the material a low incineration value. Hence they typically end up in landfill.

[0009] The most common technologies known and used today for recycling production waste from parts comprising the above-described type of bilayer are focussed on size reduction and include knife milling / grinding, chipping and shredding, with the aim to reduce the size of production waste into small shreds that can be integrated into other types of layers as filler content. However without an added value to the product so obtained. In one known process, material is shredded to obtain a tiny granulate, that is then spread between two outer non-woven layers. The so obtained sandwich is then needled and may be used in the production ofautomotive trim parts, like flooring parts or wheelhouse outer liner constructions. This type of process has however the disadvantage that only a reduced amount of recycled material may be integrated back into automotive trim parts and, in addition, the shredded tiny granulate may pose technical problems, like breaking needles during needling. However the biggest drawback of such a recycling process is that high quality material like for instance polyester fibers comprised in the fibrous layers may be mixed with low value materials and will then degrade in value.

[0010] There are also processes that are aiming at separating carpet products, but these processes concentrate on products with a thin adhesive layer rather than a thick thermoplastic layer.

[0011] Efforts to chemically separate the materials by established recycling companies to create a value added waste stream is hampered by the low amount of high quality materials, like polyesters, contained in the waste.

[0012]

[0013] To our current knowledge, there is no process on the market that is successful in separating the fibrous material from the thermoplastic elastomeric polyolefin based compound materials (TPO) forming the bilayer and enable a reuse of either the fibrous material and / or the thermoplastic material of the elastomeric layer.

[0014] Hence, it is the object of the current invention to provide a process for recycling waste material comprising multi material combinations comprising a bilayer consisting of a thermoplastic elastomeric material layer and a fibrous layer that were intertwined in a production process, as previously described.Summary of invention

[0015] The objective is achieved by a process for reclaiming material waste from automotive trim parts comprising at least a bilayer consisting of a layer of thermoplastic elastomeric compound material and a fibrous layer, according to the main claim and the claims depending on it.

[0016] In particular, by a process for reclaiming material waste from automotive trim parts comprising at least a bilayer consisting of a layer of thermoplastic elastomeric compound material and a fibrous layer wherebythe fibrous layer and the adjacent thermoplastic elastomeric layer are intertwined, said process comprising: step 1 providing a feedstock consisting of waste from automotive trim parts comprising a bilayer consisting of a layer of thermoplastic elastomeric compound TEC material and a fibrous layer, whereby the layers are intertwined;Step 2 forming feedstock F’ by reducing the feedstock provided at step I into pieces all having approximately the same size of between 5 to 60 mm, measured at the largest cross section parallel to the plane of the layers, preferably between 10 and 30mm, more preferably between 10 and 15 mm;Step 3 feeding feedstock F’ into a rotating hammer mill, whereby hammer heads are rotating along at least one perforated screen set at a distance from the tip of the hammer heads over the full rotation of the hammer, and whereby the action of the hammers is such that the thermoplastic elastomeric compound material (TEC) is broken off, separated from the fibrous material and further reduced in size to particles that are filtered through a perforated screen, thus forming a first material fraction essentially consisting of TEC (hereafter referred to as “TEC material fraction”), while the remaining fibrous material stays in the milling chamber and forms a second material fraction X, whereby the fibers in fraction X are not substantially reduced in size;Step 4 removing fibrous fraction X from the milling chamber.

[0017]

[0018] Surprisingly, by using a hammer mill, it is possible to separate thermoplastic elastomeric compound (TEC) material from the fibrous layer, whereby the TEC material obtained is clean enough to be fed back into a TEC producing step. While also the fibrous fraction may be reused again. Due to the use of the hammer mill as a size reduction and separation unit, it is possible to substantially maintain the initial length of the fibers, defined by the initial shredded piece size. The thus obtained fibrous fraction may be used as a fibrous material in a shoddy type nonwoven material mixed with other fibrous materials preferably coming from recycling sources.However as the concentration of high value material is increased the material is also interesting for standard recycling processes of external recycling companies or incineration. For instance it is possible to use the short fiber fraction as a filler in compound materials for non-automotive applications, like building materials.

[0019]

[0020] Surprisingly, the impact of the trim waste pieces forming feedstock F’ against the walls of the hammer mill and the hammers, results in a frictional stress within the bilayer. As the TEC material is not strongly bonded to the fibrous material, the TEC material will crumble and "spring” off the fibers. While the fibers will become less constrained by the loss of the TEC binding, they are more flexible and resist any further breakage in first instance. They might be chopped or chipped slightly but will essentially remain intact for the most part of the process.

[0021] The process may be further optimised by adaptation of the dwelling time during the hammer mill step, by choosing it such that a good separation can be obtained without any substantial reduction of the length of the fibers. The fibers will entangle in loose groups of fibers and can be taken out of the hammer mill chamber separately or via a continuous or discontinuous process step. Preferably an opening may be integrated into the hammer mill such that on a regular basis the fibrous material may be purged from the chamber, preferably using the centrifugal force already existing as well as the flow of air produced by the turning of the hammers. The opening may be opened on intervals just before reloading the milling chamber.

[0022] The fibrous material obtained in fraction X may be used in standard recycling processes dedicated to the material of the fibers and / or as a filler in automotive of non-automotive applications.

[0023]

[0024] The thermoplastic elastomeric compound layer may be of mixed content. It may contain inert filling material and the thermoplastic component might be a combination of one or more types of thermoplastic materials, including polyesters and / or polyolefin based materials. Preferably thethermoplastic elastomeric layer is a thermoplastic elastomeric polyolefin based layer (TPO layer) and comprises thermoplastic elastomeric polyolefin (TPO) as the basic compound forming the bulk of the material, or the main matrix component in case of a filled or highly filled layer.

[0025] For instance a flooring surface layer may be based on a polypropylene thermoplastic elastomeric layer (PP-TPO) extruded on top of or compressed together with a fibrous backing layer.

[0026] The thermoplastic elastomeric compound layer (TEC) may be a highly filed TEC layer comprising up to 90% by weight of filler and moulded together with at least one fibrous layer to form a mass layer for an acoustic trim part.

[0027] In case the trim parts comprises additional layers like a foam layer, these may be pre-separated from the bilayer construction or the trim part waste including the foam layer is reduced in size in step 1. An optional step may be introduced whereby the shredded material is separated in a cyclone separator to eliminate the foam fraction before step 2.

[0028] Both fractions - TEC and X, retrieved from the hammer mill may be subjected to a further separation process, preferably a sieving process, to eliminate small fibrous material. Dust that is produced during the hammer milling may be collected together with the TEC fraction.

[0029] All TEC fractions retrieved from the hammer mill and / or from optional following sieving steps may be subjected to a melt filtration step to eliminate any residual debris and pelletize the final TEC fraction.

[0030] The reclaimed TEC fractions may be fed into a TEC extrusion process optionally combined with virgin and / or other sourced TEC material and a TEC layer is produced. This may be combined again with a fibrous layer to form a bilayer construction. Preferably the reclaimed TEC fraction may be up to 30% by weight of the overall TEC extrudate.

[0031] The fibrous fractions may either be incinerated, or integrated in a fibrous layer, compound layer or intermediate layer for the production of an automotive trim part.

[0032] The TEC layer comprising reclaimed TEC as well as a fibrous layer, compound layer or intermediate layer comprising reclaimed fibers may be used in an automotive trim part again.

[0033]

[0034] As used herein, a thermoplastic elastomeric compound layer (TEC), preferably a polyolefin based compound (TPO) layer, is a layer that is predominantly based on a thermoplastic elastomeric material. This layer may be either used as a decorative surface cover or film and may be combined on the back with a fibrous nonwoven layer to enable adhesion to additional layers. It is the combination of the TEC surface layer with the fibrous backing layer that forms a bilayer structure for automotive floor or covering parts, like flooring, cladding or side trims.

[0035] Such TEC surface layer may comprise for instance an elastomer composition comprising a very low density ethylene polymer component and or a propylene polymer component. It may further comprise additives and colour dyes to obtain a more or less glossy appearance and to obtain a decorative pattern or colour. Furthermore the layer may be embossed to form a decorative surface. The TEC surface layer may comprise more than one layer, whereby at least the main layer is the Thermoplastic elastomeric compound material (TEC) layer, a sacrificial top surface layer or coating may be applied that may be based on polyolefin as well. The TEC surface layer is preferably a PP or PE elastomeric TPO layer.

[0036]

[0037] Alternatively thermoplastic elastomeric compound materials (TEC) may be found as backing heavy layer or mass bonding layer in insulating trim parts in a car. The TEC based materials may be a thermoplastic elastomeric polyolefin based compound material (TEC) with a filler content of at least 55 percent. Such layers may typically have a density of between 1.4 and 1 ,75kg / dm3and an area weight of up to 3 kg / m2. The polyolefin may be a polymer based on polypropylene or polyethylene.

[0038]

[0039] The fibrous layer may be a fibrous nonwoven used as decorative cover layer for the trim part, or may be used as carrier layer during theproduction of the mass / backing layer itself. The fibrous layer may be a nonwoven or scrim layer, based on staple fibers or endless filaments. Preferably staple fibers are used with an average length of between 10 and 60mm, preferably between 20 and 35mm. The fibrous layer may comprise any fibers or fibrous mixtures based on manmade fibers or natural fibers. Preferably the fibers are based on polymers or copolymers of polyester, polyamide or polyolefin or poly-lactic-acid, or based on animal fibers, like wool, or based on plant fibers, like cotton, hemp flax or similar.Preferably the fibrous layer is polyester based, preferably a polyester based on terephthalate.

[0040] The TEC layer may be a combination of multiple TEC layers. In such a construction at least one of the TEC layers is intertwined with the fibrous layer forming the bilayer structure. In a specific embodiment least one of the TEC layers may comprise a filler material. However in the reclaiming process the multilayer TEC construction can be processed completely without the need for separating the TEC layers.

[0041] As used herein, “thermoplastic elastomeric compound (TEC) layer intertwined with a fibrous layer” is meaning that the fibres of the fibrous layer are at least partially engulfed by the thermoplastic elastomeric compound (TEC) material such that separation of both materials without destroying the structure of the layers is no longer possible. In most cases it is not even possible to see the bilayer structure. Hence the bilayer may be perceived as one layer.

[0042]

[0043] A feedstock of pieces of bilayer waste material comprising at least a thermoplastic elastomeric compound material (TEC) layer intertwined with a fibrous layer, is supplied. This bilayer waste material is coming from the production of automotive trim parts like flooring parts, cladding or panels comprising at least a bilayer consisting of a TEC layer intertwined with a fibrous layer. The intertwining is related to the process of producing such layered material whereby the TEC is either directly extruded on top of a fibrous carrier layer or a thermal moulding process is compressing thelayers together forming a bilayer material that is no longer separable in single layers.

[0044] The bilayer material for the feedstock may be cut-offs, cut outs, faulty parts, or end-of-roll material as well as end of life automotive trim parts of the production of automotive trim parts comprising a bilayer consisting of a thermoplastic elastomeric compound material (TEC) layer and a fibrous layer. This bilayer may be used and produced as such or it might be combined with easily separable layers like for instance a foam layer laminated onto it. The process may comprise a pre-separating step to remove any other layers from the bilayer like, for instance, a shaving or splitting step with a knife blade.

[0045] For example, a bilayer forming a waste feedstock may consist of a TPO decorative surface layer for covering a surface in a car or truck and a fibrous backing layer, whereby the fibrous layer is intertwined with the TPO decorative surface layer at least on the backside of the TPO layer. The TPO layer may be a single layer or a combination of layers.

[0046] Another example of a bilayer forming the waste feedstock maybe a fibrous surface layer, for instance a nonwoven layer or a needle punched carpet layer, with a thermoplastic elastomeric polyolefin based compound material (TPO) backing layer, also known as mass layer or heavy layer. This layer may contain fillers up to 95% by weight.

[0047] In general the TEC layer may be a film or a foil.

[0048] The TEC layer may be foamed against in an injection foaming process, for instance with a polyurethane type foam.

[0049] The TEC layer may be sandwiched between 2 fibrous layers forming a trilayer, that may be processed the same as the bilayer material.

[0050] The fibrous nonwoven may comprise staple fibers or endless filament nonwoven materials, based on natural and / or synthetic fibers or fiber mixtures, preferably comprising polyester, preferably poly-ethylene- terephthalate (PET), polyolefin, like polypropylene or polyethylene, or polyamides, like polyamide-6 or polyamide 6-6.

[0051] The bilayer waste material is preferably free from Polyvinylchloride PVC and / or latex like styrene-butadiene resin (SBR).

[0052] In principle, any TEC layer combined with a fibrous layer forming waste of the automotive industry may be used as a feedstock for the current process. In principle clean waste, produced before the trim parts are used in the car may be used without treatment, while end of life material may be used after preferably a surface wash to reduce any dirt or grease that may interfere with the reuse of the final fractions.

[0053]

[0054] Preferably the waste material coming from the automotive trim part production or from end of life parts may be cut into smaller size pieces as defined by the inlet of the machines used in the process according to the invention. Optionally additional layers like foam layers, preferably polyurethane foam layers, may be separated before for instance by a splitting or shaving process. Small amounts of additional layers may be still be present on the waste feedstock used for the recycling process according to the invention, without reducing the effectiveness of the process itself.

[0055]

[0056] The waste feedstock is shredded or cut into pieces all having approximately the same size of between 5 to 60 mm, preferably between 10 and 30mm, more preferably between 10 and 15mm. This shredding or cutting operation is preferably accomplished with a minimal shearing of the waste feedstock to prevent any powder forming and / or breakage of the fibers to sizes smaller than the cutting size and / or plastic deformation of the TEC material.

[0057]

[0058] This shredding may be done directly before the next step of the process according to the invention or it may be separated in time and / or space. In particular, it may be advantageous to carry out this shredding already at the production site of the automotive trim part, so to minimize the space needed for storage and transport of the waste feedstock pieces.

[0059] The shredding or cutting of the waste feedstock into small shreds may be done with a conventional grinder, shredder or cutting machine known in the art. In this step the waste feedstock is only reduced in size, preferablywithout substantially producing dust. Alternatively to pre-separation, additional layers like foam layers may be reduced into smaller pieces together with the bilayer and, in the same step, they may be separated using a cyclone separator or any other technology able to separate light and heavy weight material pieces. The fraction containing the bilayer material shredded into substantially equal size pieces forms feedstock F’ for the second process step.

[0060]

[0061] The shredded feedstock F’ is fed into a rotating hammer mill, whereby hammers are rotating along at least one perforated screen set at a distance from the tip of the hammer over the full rotation of the hammer, and whereby the action of the hammers are such that the thermoplastic elastomeric compound material (TEC) is broken off and separated from the fibrous material and further reduced in size to particles that are filtered through a perforated screen or grid thus forming a first material fraction essentially consisting of TEC , while the remaining fibrous material stays in the milling chamber and forms a second material fraction X, whereby the fibers in fraction X are not substantially reduced in size through the process. Depending on the perforation in the screen, the TEC fraction may be further split into multiple material fractions consisting of substantially the TEC based material. In the first area of the hammer mill curved walls, just before the perforated screens, an intensive breaking zone may be created with rods or blades, which enable a higher impact of the flying pieces / particles with the walls. Preferably the system is laid out such that the shearing energy is not enough to melt the TEC based material.

[0062] In an additional step, or together with the previous step, the fibrous material is removed from the milling chamber.

[0063] The hammers in the hammer mill are preferably blade shaped with a blunt edge. Multiple blades may be arranged on one rotating shaft such that the tips of the hammer heads are passing along the curved hammer mill wall at an equal distance or at a distance that is reduced in the direction of rotation such that smaller particles cannot build up a layer between the perforated screen and the heads, reducing the efficacy of the hammer mill.Outer blades situated at the start or end of the shaft, having one side of the blade directly opposite to a side wall of the milling chamber may be adapted in shape to prevent forming of a material cake on these wall sides.

[0064]

[0065] During the rotation of the hammers the waste feedstock is picked up at the inlet and transported around. The fibrous fraction will remain within the milling chamber until manual removal, or may be transported to a fiber outlet orientated after the area with the perforated screens, preferably just before the inlet area of the feedstock, when related to the turning direction of the hammers. The removal may be aided with guiding plates and may be benefitting from the centrifugal force on the fibrous material obtained by the action of the hammers. The fibers may be removed continuously or intermittently via the fiber outlet. The removal of the fibrous material from the milling chamber containing the hammers may be aided by an airstream.

[0066] After the hammer mill process step at least two main material fractions are obtained: TEC fraction and X fraction. TEC fraction is comprising predominantly the TEC based material, in a particle or powder form. This fraction may be reused directly into the TEC based material process or may be further cleaned in a melt filtration step and then used in the TEC based production process.

[0067]

[0068] At least the TEC fraction may be reused in the process where the material originates from. This might be for instance the production of the TEC flooring, or the production of the mass or backing layer. In particular, in the production of the mass or backing layer it could be shown that the reclaimed TEC fraction could be used as the filler fraction without reducing the quality of the product or impairing the overall features of the trim part produced by it. To the contrary the reclaimed material is not noticeable in the product or in its properties.

[0069]

[0070] The fibrous fraction may be sieved, for instance in a cyclone separator, in a second process step to obtain a further separation of the fibrous material and any material that is not fully separated yet. This latter material may be fed back into the hammer mill for further separation.Example of the reclaiming process according to the invention.

[0071] During the production of flooring parts for vehicles including the bilayer, waste in the form of cut offs, cut outs, end of roll material and rejected parts were collected and cut into shreds of around 15 to 30mm forming the waste feedstock F. This material was fed into a hammer mill with multiple rotating hammer blades with blunt edge sides and tips.

[0072] A laboratory hammer mill was fed batch wise with feedstock and the dwell time was kept constant.

[0073] From an initial mixed TPO / fibrous waste material of 1 kg with 78% of TEC material, it was possible to retrieve 82% of the TEC material as a separate fraction. This is already a high yield considering that the process was not fully optimised yet. In particular, by further adapting the settings of the hammer mill, like speed, distance between tip of the wall and the hammer shape and size, a further increase in yield may be expected.Brief description of the drawings

[0074] Figure 1 A and B are showing cross sections of the automotive trim parts comprising at least the bilayer.

[0075] Figure 2 shows a flow diagram of the main process according to the invention

[0076] Figure 3 shows a flow diagram of the main process including optional further cleaning steps

[0077] Figure 4 shows a schematic cross section of a rotating hammer mill.

[0078]

[0079] Figure 1 is showing examples of 2 different layouts for automotive trim part constructions including the bilayer. Depending on the function of the TEC layer and of the fibrous layer, the bilayer may be visible from one side in the passenger compartment or may be hidden in the trim part.

[0080] More in general, the fibrous layer may have different functions in the automotive trim part, like carpet type surface layer (as shown in figure 1 B), airflow resistive layer, decoupling layer, or a technical function for instance to prevent sticking of the TEC layer or increasing the mechanical properties of the layer (as shown in figure 1A).

[0081]

[0082] Figure 1A is showing a cross section of a TPO flooring 10 for automotive vehicles with a large load floor area, in particular for a truck or SUV type vehicle. Such a TPO flooring is typically made or a polypropylene based TPO material with zero or low filler content. The TPO flooring 10 comprises a bilayer structure consisting of a thermoplastic elastomeric layer 20 and a fibrous backing layer 30. For such an application the thermoplastic elastomeric layer 20 is typically made of a polypropylene based TPO material with zero or low filler content. The surface of the TPO layer 20 is embossed to obtain a decorative and anti-slip flooring surface. The fibrous backing layer is intertwined with the TPO surface layer such that it is no longer possible to separate the layers without destroying them. The TPO material is penetrated between the fibers and engulfs at least partly, the fibers of the fibrous layer.

[0083] The TPO material for the surface is preferably based on a composite comprising a polyolefin elastomer resin, a filler -for instance CaCOs and optionally other polyethylene or poly propylene based resins, low density poly ethylene LDPE, linear low-density polyethylene LLDPE or high density poly Ethylene HDPE.

[0084] The fibrous nonwoven may comprise staple fibers or endless filament nonwoven materials, based on synthetic fibers or fiber mixtures, preferably comprising polyester, preferably poly-ethylene- terephthalate (PET), polyolefin, like polypropylene or polyethylene, or polyamides, like polyamide-6 or polyamide 6-6.

[0085] Alternative or in addition the fibrous layer may comprise natural fibers, like wool, hemp, cotton, flax or any other natural sourced fibrous material.

[0086] The staple fibers may comprise a mixture of different fiber materials and / or it may contain reclaimed or recycled fibers.

[0087] In addition the fibrous layer may comprise a binder, for instance in the form of binder fibers or in the form of powder based on the same material or similar as the ones mentioned for staple fibers. Preferably the binder is compatible with the staple fibers chosen such that a mixed recycling is not posing a problem. For instance a polyester based fibrous material with both staple fibers and binder based on polyester, preferably terephthalate based.

[0088] The fibrous layer may also be a spunbond nonwoven layer of endless filaments of preferably terephthalate based polyester.

[0089]

[0090] Figure 1B is showing a 3-layer construction, that is typically used for acoustic attenuation, whereby the TPO based layer 40 is forming a mass layer and a soft foam layer 60 is forming a spring layer. Both layers together function as an acoustic mass spring system that works as a sound insulation when placed inside a vehicle. The surface layer may be a simple nonwoven layer 50 or a needle punched nonwoven carpet layer. The TPO based layer may be extruded against the fibrous layer and thereby engulfing at least partly the fibrous layer forming a bilayer construction that is no longer separable into the single layers.

[0091] The materials used for the bilayer construction are in principle comparable to the ones listed above for the flooring structure. The actual polyolefin resin used might vary as well as the filler content. The mass layer function is related to a high density material hence a higher filler content might be achieved for these TPO type layers. It is known to use these TPO based heavy layer or mass layers between other layers to form an airtight barrier with a high area weight. To achieve this in a minimal thickness, highly filled materials are used. Hence, a typical TPO based heavy layer material is comprising between 70 and 95% by weight of inert filler material, like for instance CaCOs and a thermoplastic elastomer matrix.

[0092] The fibrous layer in an alternative acoustic layout according to figure 1 B may be a pile layer comprising fibers and / or filaments and / or yarns. This layer may be made of at least one polymer or co-polymer from the group of polyester, preferably terephthalate based, for instance polyethyleneterephthalate (PET), or polyamides, preferably polyamide-6 (PA6) or polyamide-66 (PA66), or polyolefins preferably polypropylene (PP), or polyethylene (PE), or mixtures from 2 or more of these polymers and / or co-polymers. The fibers, filaments and / or yarns may be based on bioresourced, reclaimed or recycled materials, or may include such type of sourced materials.

[0093]

[0094] In general the fibrous layer might be any fibrous layer for instance a nonwoven fiber layer, or a scrim layer, and may have an area weight of between 100 and 1500 g / m2. The fibrous layer may include solid fibers, hollow fibers, binder fibers or bicomponent fibers, as well as a low percentage non fibrous material like foam chips, or waste scraps.

[0095]

[0096] Optionally a foam layer, preferably polyurethane foam layer, may be used as a backing layer. The foam layer may be laminated to the bilayer structure or applied in a reaction injection foaming process whereby the foam layer is directly foamed against the surface of the bonding mass layer. A scrim might be placed in between to enable moulding of the bonding mass layer as well as increase the adhesion between the layers. Alternatively a soft fibrous layer may be laminated against the bilayer, these softer layers are not intended to be engulfed by the TPO based layer and may be only laminated to the contact surface after production of the bilayer structure. Hence these type of layers may be sheared or pulled off the bilayer structure, leaving just low amounts of fibers behind.

[0097]

[0098] The flooring as depicted in figure 1 A and the 3-layer structure as depicted in figure 1 B might be used for the production of automotive trim parts. To produce such parts the bilayer structure or the 3-layer structure may be combined with additional layers and moulded to create the shape necessary for the part to fit in the dedicated space in the vehicle. They may be used as such or even combined as floor and / or inner dash and / or surface covering in the main passenger compartment and / or as floor and / or side covering in the trunk area, and / or as cladding, panelling.

[0099]

[0100] Both product groups in figure 1A and 1 B belong to automotive trim parts that form part of the production and waste cycle as depicted in the following process flow sheets.

[0101] Automotive trim parts cut offs, cut outs, rejected parts and / or end-of-life parts are considered as waste W that may be used to feed the recycling or reclaiming process according to the invention. For the sake of the process according to the invention the bilayer structure is the core of the reclaiming process, while any additional layers are optional.

[0102] Any additional layers may be eliminated substantially by a pre-separation process to discard such layers separately. This is more advantageous as these layers maintain their basic material, and are not further mixed with other materials.

[0103]

[0104] Figure 2 is showing in a first embodiment the main process according to the invention. The feedstock F is supplied by the waste stream W coming from the automotive trim part ATP production. Whereby the main components of the waste stream are built by cut offs, cut outs, faulty parts as well as end of roll materials comprising at least a bilayer consisting of a thermoplastic elastomeric based compound material and a fibrous layer as described in detail for instance in figure 1. The fibrous layer and the TEC layer are intertwined such that the layers cannot be taken apart without impairing both layers.

[0105] The automotive trim part waste as defined is reduced in size to encompass the restriction of the following machine as well as handling, and forms the feedstock F for the reclaiming process. The feedstock F is fed into a size reduction machine Sh, like a shredder, cutter or similar machine, which is able to cut the feedstock in small pieces preferably without substantially reducing the thickness of the bilayer and or substantially modifying its properties. In particular, the size reduction process should be such that the feedstock is not subjected to considerable heat or being grind to powder. Preferably a size distribution substantiallywithin the given range is obtained with low levels of too large and too small particles.

[0106] The feedstock F’ resulting from this shredding process should have preferably an average size of between 3 to 60mm, preferably between 10 and 30 mm, more preferably between 10 and 15mm. The size of the cut or shredded pieces defines the largest fiber size that may be achieved in the later steps. In principle maintaining a larger fiber size is wanted, while a high level or pulverization may reduce the efficacy of the reclaiming process.

[0107] It is beneficial to introduce the size reduction step next to the automotive trim part production line, so that any larger parts that are rejected can be reduced in size to optimise storage and transport. Hence this step may be separate from the other steps and the smaller parts may be stored and transported in big bags. However it might be more economical and ecological to keep all steps of the recycling close to the actual automotive trim part production.

[0108]

[0109] The feedstock F' is fed into a rotating hammer mill RHM. In the rotating hammer mill the reduced-size shreds are beaten by rotating hammers, whereby the thermoplastic elastomeric polyolefin based compounded material is broken up and sieved forming a material fraction essentially consisting of TPO material, while the fibrous material may entangle without substantially reducing in size, as it is the lighter and more flexible fraction, it remains within the milling chamber. This ability to entangle with other fibers or stay in an entangled stage after the removal of the TPO makes it easy to keep the fibers inside the milling chamber and less will escape via the sieve or grid provided.

[0110] The sieve plates in the chamber should be chosen such that the fibrous material will not pass but the broken up TPO pieces / particles can pass. Optionally a grading may be introduced to divide between powder and particle size fractions of TPO. The fibrous fraction X may be taken out of the milling chamber either in a continuous or discontinuous way or batch wise, depending on the fiber fraction in the original feedstock and thethroughput of the process. The TPO fraction and / or the fibrous fraction X may be subjected to a sieving step Si to further clean the fibrous fraction from the TPO fraction.

[0111] The TPO fraction may be fed back into the automotive trim part ATP production, for instance in a TPO layer as a filler. Alternatively the reclaimed TPO may be used to produce other parts or layers for automotive products or it may be used outside the field of automotive products.

[0112]

[0113] The process may be enhanced with some optional steps to further purify and / or clarify the fractions obtained.

[0114] For instance the TPO fraction obtained may be subjected to a sieving step Si to eliminate any fibrous content X left, this fibrous fraction may be combined with the fraction obtained from the milling chamber, however this is depending on the quality of the fraction. Also the fibrous fraction may be subjected to a sieving step to obtain any pulverized or particle TPO.

[0115] Fractions may be looped back into the hammer mill for a further cycle.

[0116]

[0117] Optionally to enable a good processing and transport preferably the TPO fractions (TPO, TPO") obtained are melt filtrated MF to further clean them and pelletized to form small particulates. Any filtered impurities D may be discarded.

[0118] The thus obtained particulates TPO’ may be fed back into the production of the original TPO layer, or into a compatible TPO product. Material cut offs from this or the following processes to create automotive trim parts may be fed again into the waste recycling process indicated with the arrow, making it a closed loop process.

[0119] Surprisingly it was found that the melt filtration process under controlled temperature conditions reduced or eliminated a possible benzene release during the TPO production or from the TPO layer produced. Something that was thought to be a roadblock for reusing reclaimed TPO material.

[0120]

[0121] The reclaiming process according to the invention is sustainable; no other material is introduced, and the waste stream dedicated for landfill may be substantially reduced, down to preferably close to zero% by weight. In particular the low cost inert filler can be fully reclaimed and reused as filler, while the fibrous fraction is a small weight and may be used in fibrous layers for trim parts or is even increased in value for incineration.

[0122]

[0123] Flow scheme figure 3 is showing a comparable process as shown in figure 2, for a trim part comprising at least a 3 layer material. The trim part comprises at least a bilayer comprising thermoplastic elastomeric material and a fibrous layer, like in the other processes, and in addition it comprises an additional layer in the form of a polyurethane PUR foam, for instance a rigid or semi-rigid foam layer, adjacent either the TPO layer or the fibrous layer. The waste of such trim part production may be subjected to the shredder without pre separation of the foam layer or a first rough pre separation may be done, for instance with a shaving or splitting process using for instance knife blades (not shown). Alternatively, in particular when the foam is a substantially thin layer, the waste may be reduced to smaller particles immediately without a pre-separation. The PUR foam will be cut, delaminated or crumbled from the bilayer upon the action of the size reduction for instance in a shredder or cutting device, as it is a less strongly bonded material. Including a cyclone separator after the size reduction enables a separation of the light foam shreds and the heavier bilayer shreds. The thus obtained foam fraction may be fed in a separate foam recycling system as known in the field, while also smaller amounts may be fed back into foam production as precursor or foam filler or used in other layers for automotive trim parts.

[0124]

[0125] Figure 4 is showing a cross section of an example of the hammer mill in more detail. Feedstock F or F’(according to the schemes in figure 2 and 3) is fed via an inlet 2 into the milling chamber 3 where hammer blades 4 are rotating. The tips of the hammer blades are moving along the wall forming the milling chamber without touching. The feedstock is captured by therotating blades and smashed against the wall of the milling chamber, that may also be formed by the grid or sieve 6 or by a special impact zone with bars 8 located at the wall to increase the initial impact. Due to the impact of the particles with the wall, the sieve or the blades, the TEC material crumbles and disconnect from the fibers, while the fibers are light and elastic enough to remain in an entangled bundle. The TEC fraction is sheared out of the fibrous fraction X and pulverized. This fraction will be separated through the grid 6 and leaves the mill as TPO fraction, while the fibrous fraction X is staying inside the milling chamber, and may be released by a separate outlet 7, whereby the dotted lines indicate a possible moving outlet door. The retrieval of the fibers from the milling chamber may be done on a different way, this is just one example of for instance manual retrieval of the fibrous fraction.

[0126]

[0127] Preferably all steps are placed in a continuous line or at least on a single facility, however this is not necessary. The steps may be separated in time and / or in space. The pre-separation and / or reduction in size may be done close to the automotive trim part production, while the hammer milling and further clean up may be done in another - preferably more central- facility. The waste may be gathered from different locations, and the reclaimed fraction may be used again on different locations. Although less beneficial the fibrous fraction now no longer containing the thermoplastic elastomeric fraction may be more valuable for heat production and may be used as such.

Claims

ClaimsClaim 1. Process for reclaiming material waste from automotive trim parts comprising at least a bilayer consisting of a layer of thermoplastic elastomeric compound material and a fibrous layer whereby the fibrous layer and the thermoplastic elastomeric layer are intertwined, said process comprising the steps of:- step 1 providing a feedstock F consisting of waste from automotive trim parts comprising a bilayer consisting of a layer of thermoplastic elastomeric compound TEC material and a fibrous layer, whereby the layers are intertwined;- step 2 forming feedstock F’ by reducing the feedstock provided at step I into pieces all having approximately the same size of between 5 to 60 mm, measured at the largest cross section parallel to the plane of the layers, preferably between 10 and 30mm, more preferably between 10 and 15 mm;- step 3 feeding feedstock F’ into a rotating hammer mill, whereby hammer heads are rotating along at least one perforated screen set at a distance from the tip of the hammer heads over the full rotation of the hammer, and whereby the action of the hammers is such that the thermoplastic elastomeric compound material (TEC) is broken off, separated from the fibrous material and further reduced in size to particles that are filtered through a perforated screen, thus forming a first material fraction essentially consisting of TEC material, while the remaining fibrous material stays in the milling chamber and forms a second material fraction X, whereby the fibers in fraction X are not substantially reduced in size;- step 4 removing fibrous fraction X from the milling chamber.Claim 2. Process according to claim 1 , whereby the feedstock in step 1 further comprises a foam layer attached to either the fibrous layer or the TEC layer.Claim 3. Process according to claim 2, whereby waste material including the foam layer is subjected to a further separation step, whereby the shredded material resulting from step 1 is passed through a cyclone separator to eliminate the foam fraction before step 2.Claim 4. Process according to claim 1 , whereby the waste feedstock F used in step 1 is pre-cut in pieces.Claim 5. Process according to one of the preceding claims, whereby the TEC fraction from step 3 is subjected to a separation process, preferably a sieving process, to eliminate residual fibrous material.Claim 6. Process according to one of the preceding claims, whereby the TEC fraction from step 3 is subjected to a melt filtration step, to eliminate any residual debris, and pelletized.Claim 7. Process according to one of the preceding claims whereby the TEC material is a thermoplastic elastomeric polyolefin, preferably a thermoplastic elastomeric polypropylene or a thermoplastic elastomeric polyester based material.Claim 8. Process according to one of the preceding claims, whereby the TEC layer is a thermoplastic elastomeric multilayer, and at least one of the outer TEC layers is intertwined with a fibrous layer.Claim 9. Process according to one of the preceding claims whereby the waste material comprises a bilayer consisting of the thermoplastic elastomeric polyolefin (TPO) aesthetic surface layer and a fibrous backing layer.Claim 10. Process according to claim 7, whereby the TEC layer is a thermoplastic elastomeric multilayer with a first layer being a thermoplastic elastomeric polyolefin (TPO) surface layer with a filler content of between 0 and 7% and a second layer being a high filled thermoplastic elastomeric polyolefin (TPO) layer with a filler content of at least 55% and not more than 85% and whereby at least the second layer is intertwined with the fibrous layer.Claim 11. Process according to one of the preceding claims, whereby the TEC layer comprises inert fillers, preferably calcium carbonate.Claim 12. Process according to one of the preceding claims, whereby the reclaimed TEC fraction is fed into a TEC extrudate, and combined with regular TEC, and a TEC layer is produced.Claim 13. Process according to claim 12, whereby the reclaimed TEC fraction is up to 30% by weight of the overall TEC extrudate.Claim 14. Process according to one of the preceding claims further comprising pre-separating the bilayer from additional layers, preferably before step 1.Claim 15. Process according to one of the preceding claims, whereby the fibrous fractions are either incinerated, or integrated in a fibrous layer,compound layer or intermediate layer for an automotive trim part or for a part for a non-automotive application.Claim 16. Use of the TEC layer including the reclaimed TEC fraction of claim 12 , and / or the fibrous layer, compound layer or intermediate layer of claim 15 including the reclaimed fibrous fraction, in an automotive trim part.

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