Method for recycling automobile elastic decoration waste

Abstract

A method and apparatus for recovering waste material from automotive trim parts comprising at least two layers consisting of a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% by weight and a thermoplastic elastomer polyolefin-based backing layer having a filler content of greater than 55% by weight.

Description

Technical Field

[0001] A method and apparatus for recycling waste materials from automobile decorative parts, wherein the automobile decorative parts include at least a double layer, which is composed of a thermoplastic elastomer resin-based surface layer with a filler content of less than 5% (by weight) and a thermoplastic elastomer polyolefin-based backing layer with a filler content of more than 55% (by weight). Background Art

[0002] Floor systems for use in the cabs of trucks and the loading floor areas of SUVs and minivans have traditionally been made of polyvinyl chloride. Later, polyvinyl chloride was replaced by soft or hard-wearing surfaces based on polyolefin-based materials. These aesthetically pleasing surface layers are primarily thermoplastic elastomer polyolefin-based layers, optionally embossed with a textured or patterned surface to increase durability and visual appearance, as well as to increase adhesion of the floor.

[0003] Thermoplastic elastomer resin based surface layer can be up to 500gr / m 2 It may mainly include a polyolefin resin, or may consist of a polyolefin resin, or may further include a very small amount of a filler.

[0004] Typically, in order to be able to cover the intended floor area well, a heavier backing layer can be laminated to the non-visible side of the surface layer. This backing layer is shaped together with the surface layer to cover the area dedicated to the section of floor covering. This may include curved areas and changes in direction in flat areas to also include any channels or wall structures that need to be covered seamlessly. Typically, the backing layer is also a thermoplastic elastomer polyolefin resin-based (TPO) layer, but has different properties than the surface layer. In particular, it contains a large amount of inert fillers, such as CaCO3. The filler content can be between 55% and 98%. In addition, the weight of the backing layer used to hold the aesthetic layer to the floor can be as high as 4 kg / m 3 . At least 1.5kg / m 3 .

[0005] Although both layers are based on thermoplastic elastomer materials, preferably thermoplastic elastomer polyolefin (TPO) materials, the above-mentioned differences between the surface layer and the backing layer make recycling difficult. In fact, the recycled mixture of surface layer material and backing layer material cannot be used again to produce a backing layer or to produce a surface layer: in the case of producing a backing layer, the resulting backing layer will have reduced mechanical stiffness, while in the case of producing a surface layer, the surface layer will have reduced aesthetic value (due to the presence of fillers) and have reduced durability. In both cases, this will result in a layer that is unsuitable for producing, for example, a decorative part for a truck cabin floor covering.

[0006] As is well known, hammer mills are devices used in the recycling process of various materials, which are used for the only size reduction process step. All materials fed into the grinding chamber are crushed and pass through a grid or perforated plate in the lower area of ​​the grinding chamber.

[0007] Therefore, the object of the present invention is to provide a method for recycling waste materials from automobile decorative parts, which automobile decorative parts include at least two layers, which are composed of a low-filler content thermoplastic elastomer resin-based surface layer and a high-filler content thermoplastic elastomer polyolefin (TPO)-based backing layer laminated together, and the method is able to separate the materials of each layer again so that they can be recycled separately. Summary of the invention

[0008] The object of the present invention is achieved by a method for recycling waste materials from automobile decorative parts according to the independent claim and its dependent claims, and a device according to claim 15 and its dependent claims, wherein the automobile decorative parts have at least two layers, which are composed of a thermoplastic elastomer resin-based surface layer with a filler content of less than 5% and a thermoplastic elastomer polyolefin (TPO)-based backing layer with a filler content greater than 55%.

[0009] In particular, by a method comprising the steps of:

[0010] - Step 1: providing a raw material F consisting of automobile decorative parts waste, the decorative parts waste comprising at least a double layer consisting of a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% (by weight) and a thermoplastic elastomer polyolefin-based backing layer having a filler content of more than 55% (by weight),

[0011] - step 2: forming a feedstock F' by reducing the feedstock F provided in step 1 into flakes, said flakes all having approximately the same size, measured at the largest cross section parallel to a plane of the layer, which size is between 5 mm and 60 mm, preferably between 10 mm and 30 mm, more preferably between 10 mm and 15 mm,

[0012] - Step 3 Feeding the raw material F' into a rotary hammer mill, wherein the hammers rotate along at least one porous screen arranged at a distance from the ends of the hammers throughout the rotation of the hammers, and wherein the hammers act to cause the backing layer to break and separate from the surface layer and be crushed into particles, which are filtered through the porous screen or grid to form material portion A, while the surface layer is not substantially reduced in size and remains as flakes in the milling chamber and forms material portion B, and

[0013] - Step 4: Removal of material portion B from the grinding chamber.

[0014] Surprisingly, the impact stress caused by the hammer's blows and any collisions with the grinding chamber wall on a double-layer sheet comprising a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% and a TPO backing layer having a filler content of at least 55% introduces friction stress between and within the layers and causes the polyolefin material of the backing layer to rupture, separate from and crush the surface layer, while the thermoplastic elastomer polyolefin resin material of the surface layer remains essentially intact, enabling the two layers to be efficiently separated.

[0015] The high value surface material can now be recycled back into the surface layer production, while the filtered out portion of the backing layer material can be used again as filler in the backing layer production. Since the surface layer remains substantially intact, cross contamination of the backing layer material portion with the surface layer material portion is reduced to such an extent that both portions are suitable for use in the recycling process of the respective layer, thereby solving the problems of the prior art.

[0016] The waste materials of the raw material F may include cut-offs, cut-offs, defective parts or materials at the end of the roll from the production of automotive decorative parts and decorative parts at the end of their service life, the automotive decorative parts comprising a double layer consisting of a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% by weight and a thermoplastic elastomer polyolefin-based backing layer having a filler content of more than 55% by weight. The double layer may be used and produced as such, or the double layer may be combined with an easily separable layer such as a foam layer laminated thereon.

[0017] In principle, clean waste produced before the use of trim parts in a car can be used without treatment, while material at the end of its service life can preferably be used after surface cleaning to reduce any traces of dirt or grease that could interfere with the final part reuse.

[0018] Preferably, the waste material from the production of automotive trim parts or from parts with expired service life can be cut into smaller pieces to fit the inlet of the machine used in the method of the invention. Optionally, additional layers such as foam layers, preferably polyurethane foam layers, can be separated, for example, before by a tearing or scraping process. A small amount of additional layers may still be present in the waste raw material F used for the recycling method according to the invention without reducing the efficiency of the method itself.

[0019] Step 2, crushing, can be carried out 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 carry out this crushing at the production site of the automotive trim parts, thereby minimizing the space required for storage and transportation.

[0020] Conventional grinders, pulverizers or cutters known in the art may be used to pulverize or cut the waste material into small flakes or chips. In this step, the waste material is only reduced in size, preferably without substantially generating dust.

[0021] The bilayer material comminuted into flakes or fragments of substantially equal size forms the feedstock F' for the third method step.

[0022] The raw material F in step 1 may comprise waste material from automotive trim parts, further comprising a foam layer attached to a backing layer. Such waste material including the foam layer may be subjected to a further separation step, wherein the pulverized material produced in step 2 passes through a cyclone separator to eliminate the foam portion prior to step 3.

[0023] In an alternative embodiment, different waste streams from different production of decorative parts having at least one layer, preferably an identical or compatible backing layer, may be combined to form the feedstock F.

[0024] In an optional step, the parts A and B obtained from steps 3 and 4 can be melt filtered to eliminate any remaining debris and the debris can be granulated. The pellets thus obtained can be used in a subsequent extrusion or injection molding process for the manufacture of other parts or layers for automotive or non-automotive applications.

[0025] The method may further comprise the step of pre-separating the bilayer from the additional layer, preferably before step 1. This is possible for example for a soft layer or a surface-bonding layer which is not firmly bonded or entangled with the bilayer. These layers can be peeled or separated using, for example, a razor knife.

[0026] The thermoplastic elastomer resin material of the surface layer and / or the backing layer may include a thermoplastic elastomer polyolefin-based material, preferably a thermoplastic elastomer polypropylene, or a thermoplastic elastomer polyester-based material.

[0027] Preferably, the surface layer is a multilayer, wherein the dominant layer or layers are formed of a thermoplastic elastomer resin material and at least one layer of the outer layer is laminated to a backing layer. Additional layers may be color or pattern layers combined with a sacrificial top layer. These layers are usually adjusted from a basic thermoplastic elastomer resin material with additives such as colorants, hardeners or softeners to obtain a multilayer surface with different functional requirements.

[0028] The waste material may include a dual layer consisting of a thermoplastic elastomeric polyolefin (TPO) aesthetic surface layer and a thermoplastic elastomeric polyolefin backing layer.

[0029] More preferably, the double layer consists of a filler-free TPO surface layer and a TPO layer having a filler content of at least 55% (by weight) and not more than 95% (by weight).

[0030] The thermoplastic elastic surface layer or backing layer may contain an inert filler, preferably calcium carbonate.

[0031] The recycled fraction A or B from the process according to the invention can be fed in combination with a virgin thermoplastic elastomer material compatible with the fraction, in order to produce a thermoplastic elastomer layer, for example by means of an extrusion process. The layer thus produced can be used for automotive trim parts. Depending on the nature of the fraction and of the newly defined layer, up to 30% (by weight) of the recycled fraction can be used for the newly produced layer.

[0032] Description of Embodiments

[0033] In the implementation of the method according to the invention, the automotive decoration waste pieces are picked up at the entrance of the hammer mill and are hit by the impact plate or the rupture block in the first area of ​​the hammer mill due to the action of the hammer, wherein the crushed waste material is rebounded into the area of ​​the circulating hammer head. Preferably, the blunt hammer blade is used to increase the impact force. The waste pieces so impacted can be picked up and repeatedly hit the wall of the hammer mill or hit the grid or perforated plate, wherein the shear force between them and the hammer reduces the decoration waste pieces by breaking the high-filling material of the backing layer from the low-filling material of the surface layer and grinding the high-filling material until the particles pass through the grid or the perforated plate and leave the grinding chamber. The remaining part of the raw material piece is mainly the surface material that can be removed from the grinding chamber via a separate outlet area. Alternatively, the end of the grid or screen area has a larger opening size, and the remaining part of the chamber content can be removed through this last area.

[0034] Surprisingly, the separation of low-filled thermoplastic elastomer resin material from high-filled TPO material can be accomplished in a hammer mill device according to the present invention, which is adapted to release the remaining part from the grinding chamber in a timely manner before the remaining part is further degraded into powder or granules. Therefore, only the highly filled TPO material can be ground from the decorative waste pieces, while the low-filled thermoplastic elastomer resin material flakes remain substantially intact until released from the grinding chamber via a separate outlet. Such an outlet can be a perforated grid or grid area with a perforation size large enough to release these material pieces, or an outlet channel into which the remaining low-filled TPO material pieces are projected by the action of the hammer head and / or by the air flow generated in the grinding chamber or by a part of the grinding chamber wall that can be opened and closed.

[0035] The residence time can be optimized to ensure that the surface material does not break up and degrade into powder or granules. The surface material can be removed from the main grinding chamber intermittently, either manually or in an automatic mode. Alternatively, the size of the last grid is such that all the fragments fall through. This can be an area that is only temporarily opened to enable removal, but also ensures that the material is in the grinding chamber long enough. The filling and emptying of the grinding chamber can be a batch-like intermittent process.

[0036] In the case where the decorative part comprises additional layers, such as a foam layer on a backing layer, these layers can be separated beforehand, or the size of the decorative part waste comprising the foam layer can be reduced during the comminution process, i.e. step 2 of the method according to the invention. In this case, an optional step can be introduced whereby the comminuted material is separated in a cyclone to remove the foam portion before step 3 of the method according to the invention.

[0037] The tip speed of the hammer blades and the distance from the hammer tip to the impact plate and grid can be optimized to ensure sufficient disruptive impact on the particles to fracture the highly filled materials in a crushing manner.

[0038] The hammers in the hammer mill are preferably in the shape of blades with blunt edges. A plurality of blades may be arranged on a rotating shaft so that the ends of the hammer heads pass along the curved hammer mill wall at equal distances or at distances that decrease in the direction of rotation so that smaller particles cannot accumulate in layers between the porous screen and the head, which would reduce the efficiency of the hammer mill. The shape of the outer blades located at the beginning or end of the shaft having one side directly opposite the side walls of the grinding chamber may be adapted to prevent the formation of lumps of material on these wall sides.

[0039] During the rotation of the hammers, the waste material is picked up at the inlet and transported around. The surface portion will remain in the grinding chamber as flakes until manually removed or can be conveyed to an outlet positioned after the porous screen area, preferably just before the inlet area of ​​the raw material when the direction of rotation of the hammers is concerned. The removal can be with the aid of guide plates and can benefit from the centrifugal force on the surface material flakes obtained by the action of the hammers. The surface flakes can be removed continuously or intermittently via the fiber outlet. The surface material can be removed from the grinding chamber containing the hammers with the aid of an air flow.

[0040] After the hammer mill process step, at least two main material portions are obtained: portion B in the form of flakes consisting essentially of the thermoplastic elastomer resin-based material of the surface layer and portion A in the form of powder or granules consisting essentially of the thermoplastic elastomer polyolefin-based material of the backing layer and fillers. The elastomer material of the backing layer and its filler may be at least partially separated in the material portion A. Therefore, the filler may be contained in portion A in the form of separated particles.

[0041] Surprisingly, the difference in filler content between the two thermoplastic elastomer resin base layers allows these layers to be easily separated. In fact, a high filler content increases the brittleness or tendency to collapse of the backing layer, while the absence of fillers increases the elastic behavior of the surface layer.

[0042] The invention further encompasses an apparatus for step 3 and step 4 of the method according to the invention. Step 3 is placing the feedstock F' into a rotary hammer mill, wherein the hammer blades rotate along at least one porous screen arranged at a distance from the end of the hammer blades throughout the rotation of the hammers, and wherein the hammer blades act to cause the backing layer to break and separate from the surface layer and be crushed into particles, which are filtered through the porous screen or grid to form a first material portion A, while the surface layer is not significantly reduced in size and remains as flakes in the milling chamber and forms a second material portion B, and step 4 is removing portion B from the milling chamber.

[0043] The device for recycling waste materials from automotive trim parts comprising a double layer consisting of a surface layer based on a thermoplastic elastomer resin with a filler content of less than 5% and a backing layer based on a thermoplastic elastomer polyolefin with a filler content of more than 55% comprises the following combination:

[0044] - a grinding chamber delimited by a substantially cylindrical wall and two side walls, and

[0045] - Rotating hammers spatially arranged on a rotating shaft and with their ends facing the cylindrical wall of the grinding chamber, wherein the shaft is coaxial with the cylindrical wall and enables the hammers to rotate along the cylindrical wall in the grinding chamber, the ends of the hammers being at a distance from the same cylindrical wall during the entire rotation of the hammers, and wherein at least a portion of the cylindrical wall of the grinding chamber opposite the rotating ends of the hammer blades is a porous screen, characterised in that at least a portion of the porous screen can be opened and closed to release the contents of the grinding chamber.

[0046] Preferably, at least part of the porous screen can slide in a direction following the shape of the cylindrical wall, preferably in a direction parallel to the cylindrical wall, to open or close the grinding chamber, thereby releasing the contents of the grinding chamber. This sliding movement can be done manually, but is preferably done by an actuator for opening and closing the grinding chamber.

[0047] Preferably, opening and closing is performed in an automatic process, sequentially with filling the grinding chamber with new raw material.

[0048] Preferably, the hammer mill device according to the invention has an inlet which is customized to pre-set dimensions of automobile decoration waste fragments or flakes. The hammers in the form of blocks at the ends of arms, or in the form of discs with plate-like protrusions, or in the form of blades or similar devices, rotate along the axis and along the inner wall of the grinding chamber, but do not contact the inner surface of the wall. Preferably, a row of hammer blades is used, which are spatially arranged on the rotation axis so that the hammer blades rotate along the cylindrical wall in the grinding chamber, the ends of the hammer blades being set at a certain distance from the same cylindrical wall during the entire rotation of the hammer. The spacing between the wall surface or the crushing plate and the ends of the hammers can be adjusted to optimize the performance of the mill.

[0049] In the direction of rotation of the hammers, the wall of the grinding chamber is divided into zones.

[0050] In the first zone, the wall is closed and preferably coated with blades or bars or breaking plates to obtain a high impact zone against which the incoming material is pounded. Since the backing layer is more brittle than the surface layer, these first impacts already cause the first rupture / separation of the backing layer. At the same time, the closed wall rebounds the flakes into the rotating circle of the hammers, preventing the flakes from forming a stagnant layer outside the range of the rotating hammers.

[0051] In the second zone, one or more grids or perforated plates are aligned to form a separation area, wherein the broken smaller particles can leave the grinding chamber through the perforated plates, while the remaining larger pieces are further impacted and broken by the action of the rotating hammers and the centrifugal force, causing them to hit the grids or perforated plates.

[0052] In the last zone, at the end of the rotation, the wall can be tilted so that the remaining material can fly freely into the chute and thus leave the grinding chamber. Alternatively, the last zone has a perforated plate that can be moved away to form an outlet for the material remaining in the grinding chamber. The plate can be moved away from the cylindrical wall, or can slide parallel to the wall along the curve or shape of the cylindrical wall, thereby forming a temporary opening, and be rotated back to its initial position, thereby closing the grinding chamber again. The material passing through the plate below the perforated plate is directed to a collector. The collector can be any container suitable for storing the received material portion. In addition, the device can include a dust extraction system to prevent any dust from escaping into the air around the device. The accumulated dust can be used together with the portion that passed through the perforated plate and can be recovered together.

[0053] In case the outlet for the residue in the grinding chamber is a moving or open perforated plate, a guide system with moving baffles can be used to direct the material fraction into a separate collector in order to keep the screened fraction separated directly from the fraction coming from the grinding chamber.

[0054] The entrance to the chute may have a panel or door that can be opened and closed, depending on the residence time to break up the TPO backing layer and crush it while maintaining the surface layer flakes. Thus, the emptying of the main grinding chamber may be operated in an intermittent process, preferably alternating feeding and emptying to optimize efficiency.

[0055] In a preferred arrangement according to the invention, a side panel is integrated in the region of the last panel of the grid or screen, enabling the grid to be moved and open the grinding chamber. The screen or grid panel can be moved parallel to the grinding chamber or as a trap door away from the wall, preferably outwards.

[0056] Preferably, this zone also includes a perforated plate and normally separates part A from the grinding chamber, but a mechanism is placed in place to open the zone to manually release part B and either the perforated plate can slide aside or in the direction of the hammer rotation to create a temporary opening that leads to a separate waste reclaimer for material part B. The sliding or opening of the last zone can be by means of an actuator, which is optionally combined with an automatic control unit and / or a computer control system. Material part B can be recovered from the grinding chamber by means of an air system, and this material part can be cleared, vacuumed or blown out of the chamber. The movement of the hammer blades can generate sufficient centrifugal energy and air movement so that when the outlet door or baffle is opened, material part B is removed from the grinding chamber or at least supported for removal.

[0057] The device according to the invention may comprise a double passage system to collect the separated fractions A (the fraction that passes through the perforated plate) and B (the fraction that remains in the grinding chamber) in appropriate collectors. In the case of a sliding system for opening and closing, an additional mobile guide panel or baffle may be used in the passage system to direct each collected fraction to the correct collector. This panel or baffle may comprise its own actuator or may be combined with the actuator of the opening and closing wall.

[0058] Example

[0059] During the production of vehicle floor parts comprising two layers, waste in the form of offcuts, cutouts, coil end material and discarded parts is collected and cut into pieces of about 15 mm to 30 mm to form waste stock F. This material is fed into a device according to the invention having a plurality of rotary hammer blades with blunt edge sides and ends.

[0060] The device adds raw materials in batches and keeps the residence time constant.

[0061] 212 kg of waste material, 93% of which was backing layer material, were collected from the initial mixture of a two-layer material consisting of a TPO surface layer without fillers and a TPO backing layer with a high filler content. By means of the method according to the invention and the device according to the invention, 81% of the backing layer material could be recovered as a separate fraction A. This is already a high yield, considering that the method has not yet been fully optimized. In particular, by further adjusting the settings of the device, such as the speed, the distance between the wall ends and the shape and size of the hammers, a further increase in the yield can be expected. The backing material fraction A was successfully used as filler for the production of new backing layers. Fraction B can be further cleaned by an additional screening step. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A cross section of a decorative part providing waste material for the recycling method according to the invention is shown.

[0063] Figure 2 is a process flow chart of the method according to the present invention.

[0064] Figure 3 An apparatus for the recovery method according to the invention is shown.

[0065] Figure 4 An arrangement according to the invention is shown. DETAILED DESCRIPTION

[0066] Floor coverings for the automotive industry, known as TPO flooring, may comprise one or more layers comprising a thermoplastic elastomer polyolefin (TPO) composite material combined to form a scratch-resistant and durable surface layer, which may also be colored and / or patterned to improve the visual appearance. Such a surface layer may be combined with a heavier backing layer, i.e. containing a high content of fillers.

[0067] Figure 1 A cross section of a TPO floor for automotive vehicles with a large loading floor area, in particular for truck or SUV type vehicles, is shown. This decorative part comprises an aesthetic surface layer 1 comprising a thermoplastic elastomer resin-based material having a filler content of less than 5% by weight and an adjacent backing layer 2 comprising a thermoplastic elastomer polyolefin-based material having a filler content of at least 55% by weight, more preferably greater than 80% by weight, preferably not more than 95% by weight. The two layers together form a double layer.

[0068] For such decorative parts, the thermoplastic elastomer resin based surface layer 1 is usually made of polypropylene based TPO material with zero or low filler content. The visible side of the surface layer 1 is embossed to obtain a decorative and non-slip floor surface.

[0069] The TPO material used for the surface layer 1 or the backing layer 2 is preferably based on a compound comprising a polyolefin elastomer resin, a filler such as CaCO3 and optionally other polyethylene or polypropylene based resins such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE) or high density polyethylene (HDPE).

[0070] The backing layer may have a 1.45 kg / dm 3 Up to 1.75kg / dm 3 Density and up to 3kg / m 2 area weight.

[0071] The surface layer 1 is more preferably made of a polypropylene-based TPO material with a filler content of zero or less than 5% (by weight).

[0072] The backing layer 2 comprises 70 to 95% by weight of an inert filler material, such as CaCO3, and a thermoplastic elastomer matrix. The thermoplastic elastomer matrix may be based on a polypropylene (PP) based material or a combination of PP with LDPE, LLDPE or HDPE.

[0073] The materials contained in the surface layer or the backing layer may be based on different material mixtures, while they may further contain other additives to further enhance the mechanical or aesthetic characteristics required for the function of the layer.

[0074] The trim part can optionally include an additional layer on the side facing away from the cab or the cargo compartment. The additional layer can be a soft foam layer, such as a polyurethane foam layer or a felt layer, which can be removed before the separation step of the hammer mill.

[0075] Figure 2 and Figure 3 A preferred method according to the present invention is shown, comprising the following steps:

[0076] (Step 1) Collect automobile decorative parts waste W, which waste contains a thermoplastic elastomer resin-based material with a filler content of less than 5% (by weight) and a backing layer, which backing layer contains a thermoplastic elastomer polyolefin-based material with a filler content of at least 55% (by weight), more preferably about 80% (by weight), and preferably not more than 95% (by weight), and the waste is preferably pre-cut into relatively large pieces to form raw material F.

[0077] (Step 2) The raw material F is cut in a pulverizer or cutting device Sh so that the dimension of the cross-section parallel to the layered structure is greater than the thickness of the structure. Therefore, they are preferably more like flat sheets rather than cubic cut-outs. This ensures that the surface layer remains in the grinding chamber in the form of thin sheets after the backing layer is broken off, while the broken pieces of the backing layer are further crushed and can pass through the grid or perforated plate. If the initial pieces are already small, the separated backing layer parts may have a higher level of contamination.

[0078] (Step 3) The flakes F' of the comminuted material from step 2 are fed to a rotary hammer mill RHM, wherein the impact of the rotary hammers and the force of the flakes slamming against the walls of the milling chamber introduce internal friction stresses in the material of the flakes, to which the surface material is able to react elastically, the high filler content of the backing layer prevents this reaction, and the backing layer will break apart and separate from the surface layer. The backing layer will leave the rotary hammer mill via a screen or grid and be collected to form part A.

[0079] (Step 4) The surface layer will be collected from the grinding chamber and form Part B.

[0080] Figure 3 The same method is shown with optional further method steps.

[0081] In case the waste of trim parts additionally comprises a foam layer, the material can still be reduced in size according to step 2, but an additional cleaning step can be performed using a cyclone separator cy to eliminate most of the foam contamination. The waste W' thus obtained can be further recycled or reused.

[0082] Optionally, the obtained material parts A and B can be subjected to a melt filtration MF step to further eliminate debris D. Both parts A and B can be reused in separate new TPO material layers for automotive trim parts ATP. These ATP can again produce waste that can be recycled. Therefore, the production can be regarded as a closed-loop production with almost no waste generation.

[0083] Figure 4 A cross section of an example of a device according to the invention is shown in more detail. Figure 2 and Figure 3The raw material is captured by the rotating blades and slammed against the wall of the milling chamber, which can also be formed by a grid, a perforated plate or a 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, the perforated plate or the blades, the backing layer material breaks and separates from the surface layer material, while the elasticity of the surface layer material is sufficient to maintain its initial shape. The crushed backing layer part A is separated through the holes 5 in the perforated plate or the screen 6 and leaves the mill as material part A, while the flakes of the surface layer form part B, which cannot pass through the screen and remain inside the milling chamber. This part B can be released through a separate outlet 7, wherein the dotted line represents a possible movable outlet door. Recovering part B from the milling chamber can be carried out in different ways, which is just an example of manual removal of material part B.

[0084] Figure 4 A device according to the invention is shown, which has:

[0085] a grinding chamber 3 delimited by a substantially cylindrical wall 12 and two side walls (not shown), and

[0086] - Rotating hammer blades 4, which are spatially arranged on a rotation axis 13 and whose ends 14 face the cylindrical wall 12 of the grinding chamber, wherein the axis is coaxial with the cylindrical wall and makes the hammer blades rotate along the cylindrical wall in the grinding chamber, the ends of the hammer blades being at a distance from the same cylindrical wall during the entire rotation of the hammers, and wherein at least a portion of the cylindrical wall of the grinding chamber opposite the rotating ends of the hammer blades is a porous screen 11, characterized in that at least a portion of the porous screen 9 can be opened and closed to release the contents of the grinding chamber. The opening and closing can be, for example, a sliding movement parallel to the cylindrical wall indicated by the dashed arrows. In the following collection system, a baffle or guide plate can be moved to guide the released material. During the feeding of the grinding chamber and the actual grinding process, the broken and ground material will fall through the perforated plate and be collected as part A. When the grinding chamber is opened by removing at least a portion of the perforated plate, the baffle or guide plate can be moved so that the remaining part of the material escaping from the grinding chamber is collected as part B. These materials are materials which normally would not pass through the perforated plate.After the grinding chamber has been emptied, the gap in the perforated plate is closed again and, optionally, the guide plate or baffle is moved back to its initial position.

[0087] The movement of the perforated plate to form the gap and the movement of the baffle or guide plate 10 can be automated, for example by actuators, preferably by a computer program. The control can be carried out in sequence with the filling of the grinding chamber.

[0088] Preferably, all steps are placed in a continuous production line or at least in a single device, however, this is not necessary. These steps can be separated in time and / or space. Pre-separation and / or size reduction can be carried out close to the production of automotive decorative parts, and method step 3 using the device according to the present invention and further cleaning steps can be carried out in another device, preferably in a more central device. Waste materials can be gathered from different places, and the recovered parts can be used again in different places. Although the benefits are less, the surface part B that no longer contains the part with high filler content may be more valuable for heat generation and can be used in this way. This will still cause a large reduction in the amount of landfill, because due to the high filler content, part A forms a larger part in most of the available decorative parts waste.

Claims

1. A method for recycling waste materials from automobile decorative parts, wherein: The automotive decorative part comprises at least two layers consisting of a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% by weight and a thermoplastic elastomer polyolefin-based backing layer having a filler content of more than 55% by weight, and the method comprises the following steps: - Step 1: providing a raw material F consisting of automobile decorative parts waste, the decorative parts waste comprising at least two layers consisting of a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% by weight and a thermoplastic elastomer polyolefin-based backing layer having a filler content of more than 55% by weight; - step 2: forming a feedstock F' by reducing the feedstock F provided in step 1 into flakes, said flakes all having approximately the same size, measured at the largest cross section parallel to a plane of the layer, said size being between 5 mm and 60 mm, preferably between 10 mm and 30 mm, more preferably between 10 mm and 15 mm; - Step 3 Feeding the raw material F' into a rotary hammer mill, wherein the hammers rotate along at least one porous screen arranged at a distance from the ends of the hammers throughout their rotation, and wherein the hammers act to cause the backing layer to break and separate from the surface layer and be crushed into particles, which are filtered through the porous screen or grid to form material portion A, while the surface layer is not substantially reduced in size and remains as flakes in the milling chamber and forms material portion B, and - Step 4: Removal of material portion B from the grinding chamber.

2. The method according to claim 1, wherein: The raw material F in step 1 further comprises a foam layer attached to the backing layer.

3. The method according to claim 2, further comprising an additional step, wherein: The feedstock F' produced in step 2 is passed through a cyclone separator before step 3 to eliminate the light foam fraction.

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

5. A method according to any one of the preceding claims, wherein: The material fraction A and / or the material fraction B from step 3 are further processed in a melt filtration step to obtain clean material fraction A and / or B and to eliminate any remaining debris.

6. The method according to claim 5, further comprising a step of granulating the cleaned fractions A and / or B.

7. The method according to any of the preceding claims, further comprising pre-separating the bilayer from the additional layer, preferably before step 1.

8. A method according to any one of the preceding claims, wherein: The thermoplastic elastomer resin-based material from the surface layer comprises or consists of a thermoplastic elastomer polyolefin-based material, preferably a thermoplastic elastomer polypropylene or a thermoplastic elastomer polyester-based material.

9. A method according to any one of the preceding claims, wherein: The surface layer is a multi-layer, and at least one outer layer of the multi-layer is laminated to the backing layer.

10. A method according to any one of the preceding claims, wherein: The surface layer is based on a thermoplastic elastomeric polyolefin material and the TPO backing layer is based on a thermoplastic elastomeric polypropylene material.

11. A method according to any one of the preceding claims, wherein: The double layer consists of a surface layer and a backing layer, wherein the surface layer is composed of a thermoplastic elastomer polyolefin composite material with a filler content of 0-5%, and the backing layer is composed of a thermoplastic elastomer polyolefin material with a filler content of 55-95%, preferably not more than 90%.

12. A method according to any one of the preceding claims, wherein: The surface layer and / or the backing layer comprises an inert filler, preferably calcium carbonate (CaCO3).

13. A method according to any one of the preceding claims, wherein: The recycled fraction A or B is combined with a thermoplastic elastomeric material compatible with this fraction to produce a thermoplastic elastomeric layer, preferably by means of a process comprising an extrusion step and / or an injection molding step.

14. The method according to claim 13, wherein: The recycled material fraction may represent at most 30% by weight of the total extrudate.

15. A device for separating a double layer consisting of a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% and a thermoplastic elastomer polyolefin-based backing layer having a filler content of more than 55%, the device comprising the following combination: - a grinding chamber delimited by a substantially cylindrical wall and two side walls, and - a rotary hammer spatially arranged on the rotation axis and with its ends facing the cylindrical wall of the grinding chamber, wherein: The shaft is coaxial with the cylindrical wall and causes the hammers to rotate along the cylindrical wall in the grinding chamber, the ends of the hammers being at a distance from the same cylindrical wall throughout the rotation of the hammers, and wherein at least a portion of the cylindrical wall of the grinding chamber opposite the rotating ends of the hammer blades is a porous screen, characterized in that at least a portion of the porous screen can be opened and closed to release the contents of the grinding chamber.

16. The device according to claim 15, wherein: At least a portion of the porous screen is slidable to form an open gap in a direction parallel to the cylindrical wall, thereby opening or closing the grinding chamber and enabling removal of the contents of the grinding chamber.

17. Apparatus according to claim 15 or 16, further comprising an actuator for opening and closing the grinding chamber.

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