Method for recycling automotive elastomer trim waste

Abstract

Provided are a method and apparatus for recycling waste from automotive trim parts, the automotive trim parts including at least two layers: 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.

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for recycling waste from automotive trim parts, the automotive trim parts comprising at least two layers: a surface layer based on a thermoplastic elastomer resin having a filler content of less than 5% by weight, and a backing layer based on a thermoplastic elastomer polyolefin having a filler content of more than 55% by weight. [Background technology]

[0002] Flooring systems used in the driver compartments of trucks and the load floor areas of SUVs and small vans were traditionally made from polyvinyl chloride. This has since been replaced with soft or hard wear surfaces based on polyolefin-based materials. These aesthetic surface layers are primarily thermoplastic elastomer polyolefin-based layers, optionally embossed with a grained or patterned surface to increase durability and visual appearance, and to increase grip on the floor.

[0003] The surface layer is based on thermoplastic elastomer resin and has a density of 500gr / m 2 It may comprise primarily or consist of polyolefin resin, or may further comprise very low levels of fillers.

[0004] Typically, a heavier backing layer can be laminated to the non-visible side of the surface layer to allow for better coverage of the intended floor area. This backing layer is molded together with the surface layer to cover the area dedicated to the floor covering component. This can include transitions in the direction of curved and flat areas, and can encompass any channel or wall structure that needs to be seamlessly covered as well. Generally, the backing layer is also a thermoplastic elastomer polyolefin resin (TPO)-based layer, but has different properties from those of the surface layer. In particular, it contains a high loading of inert fillers such as CaCO3. The filler content can be 55-98%. Furthermore, the weight of the backing layer used to hold the aesthetic layer of the floor is 4 kg / m². 3 It can be up to at least 1.5 kg / m 3 weight is required.

[0005] Although both layers are based on thermoplastic elastomer materials, preferably thermoplastic elastomer polyolefin (TPO)-based materials, the aforementioned differences between the surface layer and the backing layer make recycling difficult. In fact, the recycled mixture of the surface layer material and the backing layer material cannot be reused either in the production of the backing layer or the surface layer. In the case of the backing layer, this means that the resulting backing layer has reduced mechanical rigidity, while in the case of the surface layer, the surface layer has reduced aesthetic value (due to the presence of fillers) and reduced durability. In both cases, this results in a layer that is unsuitable for the production of trim parts, for example, for the production of floor coverings in truck cabins.

[0006] Hammer mills are known as devices used for the size reduction process step in the recycling process of various types of materials. All materials fed into the milling chamber are crushed and pass through a grate or perforated plate in the lower region of this milling chamber. Summary of the Invention [Problem to be solved by the invention]

[0007] It is therefore an object of the present invention to provide a method for recycling waste from automotive trim parts comprising at least two layers: a surface layer based on a thermoplastic elastomer resin with a low content of fillers and a backing layer based on a thermoplastic elastomer polyolefin (TPO) with a high content of fillers laminated together, which method allows the materials of these layers to be separated and again to be recycled separately. [Means for solving the problem]

[0008] (Summary of the Invention) This object is achieved according to the independent claims and the claims dependent thereto, as well as initial claim 15 and the claims dependent thereto, by a method for recycling waste from automotive trim parts having at least two layers consisting of a surface layer based on a thermoplastic elastomer resin having a filler content of less than 5% and a backing layer based on a thermoplastic elastomer polyolefin (TPO) having a filler content of more than 55%.

[0009] In particular, the object of the present invention is achieved by a method comprising the following steps: - Step 1: Providing a raw material F consisting of waste automotive trim parts, comprising at least two layers consisting of a surface layer based on a thermoplastic elastomer resin having a filler content of less than 5% by weight and a backing layer based on a thermoplastic elastomer polyolefin having a filler content of more than 55% by weight; step 2: forming raw material F' by cutting the raw material F provided in step 1 into chips all having approximately the same size, measured at the largest cross section parallel to the plane of the layer, of 5 to 60 mm, preferably 10 to 30 mm, more preferably 10 to 15 mm; step 3: feeding the raw material F' into a rotary hammer mill, wherein the hammers rotate over the entire revolution of the hammer along at least one perforated screen spaced from the tip of the hammer, and the action of the hammers breaks the backing layer and breaks it into particles that separate from the surface layer and filter through a perforated screen or grid, thereby forming a material fraction A, while the surface layer remains substantially unreduced in size as flakes in the milling chamber, forming a material fraction B; and Step 4: Removing material fraction B from the milling chamber.

[0010] Surprisingly, for chips comprising two layers, a thermoplastic elastomer resin-based surface layer having a filler content of less than 5% and a thermoplastic elastomer polyolefin (TPO)-based backing layer having a filler content of at least 55%, the impact stresses induced by the hammer strikes and any collisions with the milling chamber walls result in frictional stresses between and within these layers, causing the polyolefin material of the backing layer to fracture, separate from the surface layer, and shatter, while the thermoplastic elastomer polyolefin resin material of the surface layer remains substantially intact, allowing for separation of both layers with high yields.

[0011] High-value surface material can be recycled back into the production of the surface layer, while the filtered fraction of the backing layer material can be used again as filler in the production of the backing layer. Because the surface layer remains substantially intact, cross-contamination between the backing layer material fraction and the surface layer material fraction is reduced to the extent that both fractions are suitable for use in the recycling process of their respective layers, thus solving a problem in the prior art.

[0012] Waste materials for Feedstock F can include cut-offs, cutouts, defective parts, or roll end material from the manufacture of automotive trim parts, and end-of-life trim parts, that contain a bilayer 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. This bilayer can be used and manufactured as such, or can be combined with an easily separable layer, such as a foam layer, laminated thereon.

[0013] In principle, clean waste generated before the trim parts are used in the automobile can be used without treatment, while end-of-life material can preferably be used after surface cleaning to reduce any traces of dirt or grease that may hinder the reuse of the final fraction.

[0014] Preferably, waste from automotive trim part production or end-of-life parts can be cut into smaller pieces to fit into the inlet of the device used in the method according to the invention. Additional layers, such as foam layers, preferably foamed polyurethane layers, can be separated beforehand, for example by a splitting or shaving step. Small amounts of additional layers may still be present in the waste material F used for the recycling process according to the invention, without reducing the effectiveness of the process itself.

[0015] The shredding in step 2 can take place immediately before the next step of the method according to the invention or can be separated in time and / or space. In particular, it can be advantageous to perform this shredding already at the manufacturing site of the automotive trim parts, minimizing the space required for storage and transportation.

[0016] This shredding or cutting of the waste material into small chips or pieces can be done using conventional grinders, shredders or cutters known in the art, and in this step the waste material is only reduced in size, preferably without producing substantial dust.

[0017] The bilayer material chopped into chips or pieces of substantially equal size forms feedstock F' for the third process step.

[0018] Feedstock F in Step 1 can include waste from automotive trim parts that further include a foam layer attached to a backing layer. Such waste containing a foam layer can be subjected to a further separation step, in which the shredded material from Step 2 is passed through a cyclone separator to remove the foam fraction prior to Step 3.

[0019] In an alternative embodiment, different waste streams from the manufacture of different trim parts that have at least one layer, preferably a backing layer, in common or compatible can be combined to form Feedstock F.

[0020] Optionally, Fraction A and Fraction B obtained from Steps 3 and 4 can be melt filtered to remove any remaining debris and pelletized. The pellets thus obtained can be used in subsequent extrusion or injection molding processes to produce other parts or layers for automotive or non-automotive applications.

[0021] The method of the present invention can further comprise a step of pre-separating the bilayer from additional layers, preferably before step 1. This is possible, for example, for fluffy or surface-bound layers that are not strongly bound or entangled with the bilayer. These layers can be peeled or separated, for example, using a blade knife.

[0022] The thermoplastic elastomer resin material of the surface layer and / or backing layer may comprise a thermoplastic elastomer polyolefin-based material, preferably a thermoplastic elastomer polypropylene, or a thermoplastic elastomer polyester-based material.

[0023] Preferably, the surface layer is multi-layered, with one or more primary layers being formed from a thermoplastic elastomer resin material, and at least one of the outer layers being laminated to a backing layer. Additional layers may be colored or patterned layers combined with a sacrificial top layer. These layers are typically formed from a base thermoplastic elastomer resin material modified with additives such as colorants or hardeners or softeners to obtain a multi-layer surface with various functional requirements.

[0024] The waste product may include two layers: a thermoplastic elastomeric polyolefin (TPO) aesthetic surface layer and a thermoplastic elastomeric polyolefin backing layer.

[0025] More preferably, the two layers consist of a filler-free thermoplastic elastomeric polyolefin (TPO) surface layer and a thermoplastic elastomeric polyolefin (TPO) layer having a filler content of at least 55% by weight and not more than 95% by weight.

[0026] The thermoplastic elastomer surface or backing layer may contain an inert filler, preferably calcium carbonate.

[0027] The recycled fraction A or B from the process according to the invention can be mixed with a virgin thermoplastic elastomer material that is compatible with this fraction and then fed to produce a thermoplastic elastomer layer, for example by an extrusion process. The layer thus produced can be used in automotive trim parts. Depending on the fraction and the properties of the newly defined layer, up to 30% by weight of the recycled fraction can be used in the newly produced layer. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 shows a cross section of a trim component that provides the waste material for the recycling process according to the present invention. [Figure 2] FIG. 2 is a process flow sheet for a process according to the present invention. [Figure 3] FIG. 3 shows an apparatus for the recycling process according to the present invention. [Figure 4] FIG. 4 shows an apparatus according to the invention. [Figure 5] FIG. 5 shows an apparatus according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] (Description of the embodiment) In the implementation of the method according to the present invention, small pieces of automotive trim waste are picked up at the inlet of the hammer mill and, thanks to the action of the hammers, collide with an impact plate or crushing block in the first zone of the hammer mill, where the shredded waste is bounced back into the area of ​​the rotating hammer head. Preferably, blunt hammer blades are used to increase the impact force. The thus-collided waste chips can be picked up and impacted multiple times against the walls of the hammer mill or against a grid or perforated plate, where the shear forces between the chips and the hammers remove the highly-packed material of the backing layer from the less-packed material of the surface layer and reduce the size of the trim waste particles by crushing them until the particles pass through the grid or perforated plate and exit the milling chamber. The remainder of the raw material particles is primarily surface material, which can be removed from the milling chamber through a separate exit zone. Alternatively, the end of the grid or sieve zone has larger openings, and the remainder of the chamber contents can be removed through this last zone.

[0030] Surprisingly, separation of the lightly filled thermoplastic elastomer resin material from the highly filled TPO material can be carried out in a hammer mill apparatus according to the present invention, which is adapted to discharge the remaining fraction from the milling chamber just before it is further reduced to powder or particles. Thus, only the highly filled TPO material can be ground from the trim waste pieces, while the lightly filled thermoplastic elastomer resin material flakes remain substantially intact until they are discharged from the milling chamber via a separate outlet. Such an outlet can be either a perforated grate or grid area with perforations large enough to discharge these material pieces, or an outlet channel into which the remaining lightly filled TPO material pieces are discharged by the action of the hammer heads and / or by an airflow generated inside the milling chamber by a portion of the milling chamber wall that can be opened or closed.

[0031] Residence time can be optimized to ensure the surface material does not crumble and break down into powder or particles. Surface material can be removed intermittently from the main milling chamber in a manual or automated fashion. Alternatively, the final grid size is such that all fragments fall out. This can be an area that is only temporarily opened to allow removal, but ensure that the material remains in the milling chamber long enough. Filling and emptying the milling chamber can be a batch-like interval process.

[0032] If the trim part comprises additional layers, such as a foam layer relative to the backing layer, these layers can be separated beforehand, or the trim part waste comprising the foam layer can be reduced in size during the shredding process (i.e., step 2 of the method according to the invention). In this case, an optional step can be introduced in which the shredded material is separated in a cyclone to remove the foam fraction before step 3 of the method according to the invention.

[0033] The tip speed of the hammer blade and the distance from the tip of the hammer to the impact plate and grate can be optimized to ensure a breaking impact on the particles sufficient to break highly loaded materials with a comminuting means.

[0034] The hammers in the hammer mill are preferably blades with blunt edges. Multiple blades can be arranged on a single rotating shaft, so that the tips of the hammer heads pass along the curved hammer mill wall at equal or decreasing distances in the direction of rotation, preventing smaller particles from forming a layer between the perforated screen and the head that would reduce the effectiveness of the hammer mill. The outer blades, located at the beginning or end of the shaft and with one side directly facing the side walls of the milling chamber, can be shaped to prevent material cakes from forming on these walls.

[0035] During the rotation of the hammers, the waste material is picked up at the inlet and transported to the periphery. The surface fraction may remain in the milling chamber as flakes until manually removed, or may be transported to an outlet directed after the area with the perforated screen, preferably just before the inlet area of ​​the material, relative to the direction of rotation of the hammers. Removal may be assisted by a guide plate and may benefit from the centrifugal force on the surface material flakes obtained by the action of the hammers. The surface flakes may be removed continuously or intermittently via the fiber outlet. Removal of the surface material from the milling chamber, including the hammers, may be assisted by an airflow.

[0036] After the hammer milling process, at least two main material fractions are obtained: Fraction B, which is in the form of thin flakes consisting essentially of the thermoplastic elastomeric resin-based material of the surface layer, and Fraction A, which is in the form of powder or granules consisting essentially of the thermoplastic elastomeric polyolefin-based material of the backing layer and the filler. The elastomeric material of the backing layer and its filler can be at least partially separated in material Fraction A. Thus, the filler can be contained in Fraction A in the form of separate particles.

[0037] Surprisingly, the difference in filler content between the two thermoplastic elastomer resin-based layers allows for easy separation of these layers. In fact, a high filler content increases the brittleness or tendency to crumble of the backing layer, while the absence of filler increases the elastomeric behavior of the surface layer.

[0038] The present invention further comprises an apparatus for steps 3 and 4 of the method according to the invention, wherein in step 3, raw material F' is fed to a rotary hammer mill, wherein the hammer blades rotate along at least one perforated screen spaced from the tips of the hammer blades over the full revolution of the hammer, and the action of the hammer blades breaks the backing layer and breaks it into particles that separate from the surface layer and are filtered through the perforated screen or grid, thereby forming a first material fraction A, while the surface layer is not substantially reduced in size and remains as flakes in the milling chamber to form a second material fraction B, and in step 4, fraction B is removed from the milling chamber.

[0039] Such an apparatus for recycling waste from automotive trim parts comprising a bilayer 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% comprises, in combination: - a milling chamber bounded by an essentially cylindrical wall and two side walls, and - rotary hammers spatially constructed on a rotation axis and with their tips pointing towards the cylindrical wall of the milling chamber; wherein the shaft is coaxial with the cylindrical wall and the hammers rotate in the milling chamber along the cylindrical wall with their tips spaced apart from the same cylindrical wall throughout the entire revolution of the hammer; and At least a portion of the cylindrical wall of the milling chamber opposite the rotating tip of the hammer blade is a perforated screen, and at least a portion of the perforated screen can be opened and closed to release the contents of the milling chamber.

[0040] Preferably, at least a portion of the perforated screen is slidable in a direction that conforms to the shape of the cylindrical wall, preferably parallel to the cylindrical wall, to open and close the milling chamber and release the contents of the milling chamber. This sliding movement can be performed manually, but is preferably performed by an actuator that opens and closes the milling chamber.

[0041] Preferably, the opening and closing is done in an automated process in sequence with filling the milling chamber with new feedstock.

[0042] Preferably, the hammer mill apparatus according to the present invention has an inlet adapted to accommodate pre-sized pieces or chips of automotive trim waste. The hammer, either in the form of a block at the end of an arm, or in the form of a disk with, for example, protrusions or blade-like plates, or similar devices, rotates along its axis and along the inner wall of the milling chamber without touching the inner surface of the wall. Preferably, an array of hammer blades is used, the hammer blades being spatially organized on the rotation axis so that the hammer blades rotate within the milling chamber along the cylindrical wall with their tips spaced apart from said same cylindrical wall throughout the entire hammer rotation. The space between the wall or crushing plate and the tips of the hammer may be adjustable to optimize the performance of the mill.

[0043] In the direction of rotation of the hammer, the wall of the milling chamber is divided into a number of zones.

[0044] In the first zone, the wall is closed and preferably covered with blades, bars or crushing plates to create a high-impact zone against which the incoming material is crushed. Since the backing layer is more brittle than the surface layer, these initial impacts already cause the initial fracture / separation of the backing layer. At the same time, the closed wall bounces the chips back into the hammer's rotation circle, preventing a stagnant layer of chips from forming outside the reach of the rotating hammer.

[0045] In the second zone, one or more grids or perforated plates are lined to form a separation region where the broken smaller particles can exit the milling chamber through the perforated plates, while the remaining larger pieces are further impacted and broken down by the action of the rotating hammers and the centrifugal force as they impact the grids or perforated plates.

[0046] In the final zone, the wall is inclined at the end of the turn, allowing the remaining material to freely spill into a chute and thereby exit the milling chamber. Alternatively, the final zone may have a movable perforated plate to create an outlet for the material remaining in the milling chamber. This plate can move away from the cylindrical wall or slide parallel to the wall, following the curve or shape of the cylindrical wall, to create a temporary opening and then return to its initial position to reclose the milling chamber. Material that passes through the plate below the perforated plate is directed to a collector. The collector can be any container suitable for holding the received material fraction. Furthermore, the device may be equipped with a dust suction system to prevent any dust from escaping into the air surrounding the device. The collected dust can be used and recycled together with the fraction that passed through the perforated plate.

[0047] If the outlet for the residue in the milling chamber is a moving or opening perforated plate, a guide system with moving flaps can be used to guide the material fraction to a separate collector, keeping the sieved fraction directly separate from the fraction coming from the milling chamber.

[0048] The entrance to the chute can have a panel or door that can be opened or closed depending on the residence time required to break down and grind the TPO backing layer while maintaining the flakes in the surface layer. Thus, emptying the main milling chamber can be operated as an intermittent process, preferably alternating between feeding and emptying to optimize effectiveness.

[0049] In a preferred device according to the invention, side panels are integrated in the area of ​​the last panel of the grid or sieve, allowing the grid to be moved and the milling chamber to be opened: the sieve or grid plate can be moved parallel to the milling chamber or as a trap door, preferably outwards, away from the wall.

[0050] Preferably, this zone also contains a perforated plate, which normally separates fraction A from the milling chamber; however, some mechanism may be incorporated to open this zone to manually release fraction B and / or to slide the perforated plate sideways or in the direction of the hammer rotation to create a temporary opening that directs material fraction B to a separate waste collector. The sliding or opening of the last zone may optionally be assisted by an actuator in combination with an automatic control unit and / or a computerized control system. The removal of material fraction B from the milling chamber may be assisted by an air system, and such material fraction may be removed, vacuumed, or blown out of the chamber. The movement of the hammer blades may generate sufficient centrifugal energy and air movement to remove material fraction B from the milling chamber, or at least assist in its removal when the exit door or flap is opened.

[0051] The device according to the invention can include a double pass-through system, collecting fraction A, i.e., the fraction passing through the perforated plate, and separately collecting fraction B, i.e., the fraction remaining in the milling chamber, in the appropriate collector. In the case of a sliding system for opening and closing, an additional moving guide panel or flap can be used in the pass-through system to guide each of the collected fractions to the correct collector. This panel or flap can have its own actuator or can be combined with an actuator that opens and closes the wall. [Example]

[0052] During the manufacture of two-ply vehicle flooring components, waste in the form of off-cuts, cut-outs, roll material ends, and rejected parts was collected and cut into pieces of approximately 15-30 mm to form waste feedstock F. This material was fed into an apparatus according to the present invention equipped with a number of rotating hammer blades having blunt cutting edges and points.

[0053] The raw materials were fed to the apparatus in batches to maintain a constant residence time.

[0054] From the initial mixture of two-layer material consisting of a filler-free TPO surface layer and a TPO backing layer with a high filler content, 212 kg of waste material was collected, containing 93% backing layer material. Using the method and the apparatus according to the present invention, it was possible to recover 81% of the backing layer material as a separate fraction A. This is already a high yield, considering that the process has not yet been fully optimized. Further increases in yield can be expected, especially by further adapting the equipment settings, such as speed, distance between the wall and tip, and hammer shape and size. Backing material fraction A was successfully used as filler in the production of new backing layers. Fraction B could be further purified by an additional sieving step.

[0055] Floor coverings used in the automotive industry, known as TPO flooring, can incorporate one or more layers containing thermoplastic elastomeric polyolefin (TPO) compound materials to form a scratch-resistant and durable surface layer, which may also be colored and / or patterned to improve visual appearance. Such a surface layer can be combined with a heavier backing layer, i.e., one containing a high filler content.

[0056] 1 shows a cross section of such a TPO flooring for an automotive vehicle with a large load floor area, particularly a truck or SUV type vehicle. Such a trim 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, and preferably not more than 95% by weight. Both layers together form a bilayer.

[0057] For such trim parts, the thermoplastic elastomer resin-based surface layer 1 is typically made from a polypropylene-based TPO material with zero or low filler content. The visible side of the surface layer 1 is embossed to provide a decorative, non-slip flooring surface.

[0058] The TPO material 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).

[0059] Backing layer: 1.4 to 1.75 kg / dm 3 density and 3kg / m 2 It can have an area weight of up to

[0060] The surface layer 1 is more preferably made of a polypropylene-based TPO material with zero or low filler content, ie less than 5% by weight.

[0061] The backing layer 2 comprises 70-95% by weight of an inert filler material, such as CaCO3, and a thermoplastic elastomer matrix, which may be based on a polypropylene (PP)-based material or a combination of PP with LDPE, LLDPE, or HDPE.

[0062] Both the materials contained in the surface layer or the backing layer can be based on different material mixtures, while they can also contain other additives to further enhance the mechanical or aesthetic characteristics required for the function of the layer.

[0063] The trim portion may optionally include an additional layer on the side facing away from the driver compartment or the load compartment, which may be a flexible foam layer such as a polyurethane foam layer or a felt layer that can be removed prior to the separation step in the hammer mill.

[0064] 2 and 3 show a preferred method according to the present invention, which comprises the following steps:

[0065] (Step l) A waste W of automotive trim parts ATP comprising a thermoplastic elastomer resin-based material having a filler content of less than 5 wt. % and a backing layer comprising a thermoplastic elastomer polyolefin-based material having a filler content of at least 55 wt. %, more preferably more than 80 wt. % and preferably not more than 95 wt. % is collected and preferably pre-cut into pieces of a certain size to form a raw material F.

[0066] (Step 2) The raw material F is cut with a shredder or cutting device Sh so that the cross section in the dimension parallel to the layered structure is larger than the thickness of this structure. They are therefore preferably more like flat chips rather than cubic cuts. This ensures that the surface layer after the backing layer is broken remains in the milling chamber in the form of flakes, while the broken pieces of the backing layer can be further broken down and passed through the grid or perforated plate. If the initial pieces are already small, the separated backing layer fraction may have a higher level of contamination.

[0067] (Step 3) The chopped feedstock F' chips from Step 2 are fed into a rotary hammer mill RHM, where the impact of the rotating hammers and the force of the chips colliding with the walls of the milling chamber create internal frictional stresses within the chip material; whereas the surface material is able to react elastically to this stress, the high filler content of the backing layer prevents such a reaction, causing the backing layer to disintegrate and separate from the surface layer. The backing layer exits the rotary hammer mill through a sieve or grid and is collected to form fraction A.

[0068] (Step 4) The surface layer is collected from the milling chamber to form fraction B.

[0069] FIG. 3 shows the same process with optional additional process steps.

[0070] If the trim part waste additionally contains a foam layer, this material can still be reduced in size according to step 2, but an additional washing step using a cyclone separator Cy can be used to remove most of the foam contamination. The waste W' thus obtained can be further recycled or reused.

[0071] Optionally, the resulting material fractions A and B can be subjected to a melt filtration MF step to further remove debris D. Both fractions A and B can be reused in separate new TPO material layers for the automotive trim parts ATP. These ATPs can again generate waste that can be recycled. Therefore, this production can be considered a closed-loop production with near-zero waste.

[0072] Figure 4 shows a cross section of an example of an apparatus according to the invention in more detail. Raw material F' (according to the schemes of Figures 2 and 3) is fed via inlet 2 into milling chamber 3, where hammer blades 4 rotate. The tips of the hammer blades move along the cylindrical wall forming the milling chamber without touching it. The raw material is captured by the rotating blades and impacts the wall of the milling chamber. This impact can be achieved by a grid or sieve 6 or by a special impact zone with bars 8 located in the wall to increase the initial impact. Due to the impact of the particles with the wall, perforated plate, or blade, the backing layer material disintegrates and separates from the surface layer material, which remains elastic enough to retain its original shape. The crushed backing layer fraction A is separated through the holes 5 of the perforated plate or sieve 6 and leaves the mill as material fraction A, while the surface layer flakes form fraction B, which cannot pass through the sieve, and remain in the milling chamber. This fraction B can be discharged by a separate outlet 7, where the dotted line indicates the possible movement of the outlet door. The withdrawal of fraction B from the milling chamber can be done in various ways, this being just one example, for example, manual withdrawal of material fraction B.

[0073] FIG. 5 shows a device according to the invention, comprising: a milling chamber 3 bounded by a substantially cylindrical wall 12 and two side walls (not shown), and a rotary hammer blade 4 spatially constructed on a rotating shaft 13, with a tip 14 pointing towards the cylindrical wall 12 of the milling chamber; Here, the axis is coaxial with the cylindrical wall, and the hammer blades rotate within the milling chamber along this cylindrical wall, their tips spaced apart from the same cylindrical wall throughout the entire rotation of the hammer. At least a portion of the cylindrical wall of the milling chamber opposite the rotating tips of the hammer blades is a perforated screen 11, and at least a portion of the perforated screen 9 can be opened or closed to release the contents of the milling chamber. This opening and closing can be, for example, a sliding movement parallel to the cylindrical wall, as indicated by the dashed arrow. A flap or guide plate can be moved to guide the released material in a collection system below. During the feed into the milling chamber and the actual milling process, the crushed and pulverized material falls through the perforated plate and is collected as fraction A. When the milling chamber is opened by releasing at least a portion of the perforated plate, the flap or guide plate can be moved to collect the remaining portion of the material leaving the milling chamber as fraction B. This is typically the material that does not pass through the perforated plate. After emptying the milling chamber, the gap in the perforated plate is closed again and, optionally, the guide plate or flap is returned to its original position.

[0074] The movement of both the perforated plate to form the gap and the flap or guide plate 10 can be automated, for example by means of an actuator, preferably by means of a computer program, and this control can be in sequence with the filling of the milling chamber.

[0075] Preferably, all steps are arranged in a continuous line, or at least on a single facility, although this is not necessary. These steps may be separated in time and / or space. Pre-separation and / or size reduction may be performed near the automotive trim part production, while process step 3 using the device according to the invention and further cleaning steps may be performed in a separate, preferably more centralized, facility. Waste can be collected from various locations, and the reclaimed fractions can be reused in various locations. The less valuable, but still highly filler-containing, surface fraction B may be more valuable for heat generation and can be used as is. This still results in a significant reduction in landfill space, since fraction A forms a larger fraction in the majority of available trim part waste due to its high filler content.

Claims

1. 1. A method for recycling waste from automotive trim parts, comprising: The automotive trim part comprises at least two layers: a surface layer based on a thermoplastic elastomer resin having a filler content of less than 5% by weight; and a backing layer based on a thermoplastic elastomer polyolefin having a filler content of more than 55% by weight; The method comprises the steps of: Step 1: Providing a raw material F consisting of waste automotive trim parts, comprising at least two layers: a surface layer based on a thermoplastic elastomer resin having a filler content of less than 5% by weight, and a backing layer based on a thermoplastic elastomer polyolefin having a filler content of more than 55% by weight; step 2: forming a raw material F' by cutting the raw material F provided in step 1 into chips all having approximately the same size, measured in the largest cross section parallel to the plane of the layer, between 5 and 60 mm, preferably between 10 and 30 mm, more preferably between 10 and 15 mm; step 3: feeding the raw material F' into a rotary hammer mill, wherein the hammers rotate over the entire revolution of the hammer along at least one perforated screen spaced from the tip of the hammer, and the action of the hammers breaks the backing layer and breaks it into particles that separate from the surface layer and filter through a perforated screen or grid, thereby forming a material fraction A, while the surface layer remains substantially unreduced in size and remains as flakes in the milling chamber, forming a material fraction B; and Step 4: Removing material fraction B from the milling chamber.

2. 10. The method of claim 1, wherein the feedstock F in step 1 further comprises a foam layer attached to the backing layer.

3. 3. The method of claim 2, further comprising the additional step of passing said feedstock F' from step 2 through a cyclone separator to remove a light foam fraction prior to step 3.

4. 2. The method of claim 1, wherein the raw material F used in step 1 is pre-cut into small pieces.

5. 5. The method according to any one of claims 1 to 4, wherein material fraction A and / or 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 remove any remaining debris.

6. 6. The method of claim 5, further comprising a pelletizing step of said clean material fractions A and / or B.

7. The method of any one of claims 1 to 6, further comprising, preferably before step 1, a pre-separation of said two layers from any additional layers.

8. 8. The method according to any one of claims 1 to 7, 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. The method according to any one of claims 1 to 8, wherein the surface layer is multi-layered, and at least one of the outer layers in the multi-layered structure is laminated to the backing layer.

10. 10. The method according to any one of claims 1 to 9, wherein the surface layer is based on a thermoplastic elastomeric polyolefin material and the thermoplastic elastomeric polyolefin (TPO)-based backing layer is based on a thermoplastic elastomeric polypropylene material.

11. 11. The method according to any one of claims 1 to 10, wherein the two layers consist of a surface layer made of a thermoplastic elastomeric polyolefin compound material having a filler content of 0 to 5% and a backing layer made of a thermoplastic elastomeric polyolefin material having a filler content of 55% to 95%, preferably up to 90%.

12. The surface layer and / or the backing layer may comprise an inert filler, preferably calcium carbonate (CaCO ３ 12. The method of claim 1, comprising:

13. 13. The method according to any one of claims 1 to 12, wherein the recycled fraction A or B is mixed with a thermoplastic elastomer material compatible with said fraction to produce a thermoplastic elastomer layer, preferably by a process comprising an extrusion and / or injection molding process.

14. 14. The method of claim 13, wherein the regenerated material fraction is at most 30% by weight of the total extrudate.

15. 1. An apparatus for separating two layers 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%, comprising: An apparatus comprising in combination: a milling chamber bounded by an essentially cylindrical wall and two side walls, and rotary hammers, which are spatially constructed on a rotation axis and whose tips point towards the cylindrical wall of the milling chamber; wherein the shaft is coaxial with the cylindrical wall and the hammers rotate in the milling chamber along the cylindrical wall with their tips spaced apart from the same cylindrical wall throughout the entire revolution of the hammer; and At least a portion of the cylindrical wall of the milling chamber opposite the rotating tip of the hammer blade is a perforated screen, and at least a portion of the perforated screen can be opened and closed to release the contents of the milling chamber.

16. 16. The apparatus of claim 15, wherein at least a portion of the perforated screen is slidable to form an open gap in a direction parallel to the cylindrical wall, thereby enabling the milling chamber to be opened and closed and the contents of the milling chamber to be removed.

17. 17. The apparatus of claim 15 or 16, further comprising an actuator for opening and closing the milling chamber.

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