Covering layer for visible use surfaces of automotive trim parts

Abstract

A cover layer for an automotive trim component includes a porous fibrous carrier layer and a polymeric thermoplastic matrix wherein the polymeric thermoplastic matrix and the porous fibrous carrier layer form a composite layer that forms a visible face of the cover layer. In the composite layer, the polymeric thermoplastic matrix wraps the fibers of the carrier layer and fills pores between the fibers such that the porous fibrous carrier layer remains visible through the thermoplastic polymer matrix itself from the visible face of the cover layer.

Description

Technical Field

[0001] This invention relates to the field of automotive trim components installed inside and / or on the exterior of road vehicles. Background Technology

[0002] Many automotive trim components include surfaces that may undergo significant wear and tear over the life of the vehicle, while remaining visible to the vehicle's passengers and occupants. Typical examples of such trim components are trunk floor covers or passenger compartment floor covers (including floor mats), particularly for vans, SUVs, pickup trucks, and light commercial vehicles.

[0003] Typically, the visible surfaces of these components are covered by a coating, which may need to provide different functions. On one hand, they can be used to achieve a desired appearance, such as a particular color, texture, or surface design. On the other hand, the same coating can be used to protect the components from external mechanical stresses, such as impacts and scratches caused by friction exerted on them, for example, by passengers' feet and / or objects during loading / unloading operations. In addition, the coating can also be used to protect the components from the penetration of moisture or liquids, especially in areas that require regular cleaning and / or washing, such as storage areas, particularly in VANs and / or pickup trucks and / or light commercial vehicles.

[0004] Over time, to perform all the aforementioned functions, the overlays used by automakers on the visible surfaces of automotive trim components have evolved into complex structures comprising various types of materials, typically arranged in multiple layers, each of which may primarily serve a specific function. Typical materials used for these overlays are polymeric materials, such as TPO and / or EPDM and / or RIM-PU, which can be used in combination with thin nonwoven fabrics.

[0005] For example, CN208914720 discloses a vehicle carpet comprising a cover layer consisting of an EPDM layer and a TPO layer disposed on the upper surface of the EPDM layer. The TPO layer includes a TPO base layer, a coating printed on the TPO base layer and having color and / or texture, and a transparent layer laminated on the upper surface of the coating. Additionally, a thin fiber nonwoven layer may optionally be added to the lower surface of the EPDM layer. According to CN208914720, the transparent layer primarily functions to prevent wear of the printed coating, which in turn primarily ensures the visible appearance of the component. According to CN208914720, the EPDM layer enhances the sound insulation of the cover layer, while the thin fiber nonwoven layer (when present) provides shock absorption.

[0006] EP3366463 discloses a decorative component with a cover layer for motor vehicles, the cover layer comprising a carrier layer, a decorative printed thermoplastic film coated on the upper surface of the carrier layer, and a varnish layer coated on top of the printed thermoplastic film. According to EP3366463, the carrier layer preferably consists of a polymer layer with a thin fibrous nonwoven layer coated on its back side. The polymer layer is preferably composed of PP or TPO. The decorative printed thermoplastic film can depict images such as nonwoven fabrics, felt, wood grain, woven fabrics, knitted fabrics, carpets, etc. The top varnish layer, preferably composed of PU varnish, protects the decorative film from external influences such as impacts and scratches, while the carrier layer imparts mechanical resistance and dimensional stability to the decorative component.

[0007] While existing coatings (such as those described above) offer an acceptable balance of pleasing appearance, abrasion resistance, washability, and mechanical resistance, they may also have some drawbacks.

[0008] The visible appearance of this type of overlay typically relies on a printed layer that presents a regular pattern and / or depicts an image (such as representing wood grain, woven fabric, etc.). However, due to the unnatural regularity and / or the inherent two-dimensionality of the printed layer, the resulting effect is often perceived as artificial by vehicle users. Furthermore, if the decorative printed layer is worn or scratched during the vehicle's lifespan, this damage remains clearly visible on the printed decorative surface throughout the vehicle's entire lifespan, as there is no way to repair the printed decorative layer. In addition, the printed pattern and / or image may deform during any molding operations required to manufacture the overlay.

[0009] In addition, polymer layers (such as TPO layers) commonly used in existing surface coatings may suffer from premature aging and / or seam failure because the component may be subjected to intense thermal cycling during the vehicle's lifespan. Furthermore, these layers have rather poor elongation properties and low tensile strength, so they may crack or thin significantly during production processes involving molding operations, thereby impairing the mechanical properties of the final trim component.

[0010] The object of the present invention is to provide a covering layer for the surface of automotive trim parts (which overcomes the aforementioned limitations of prior art covering layers) and a trim part including such a covering layer and a method for manufacturing the same. Summary of the Invention

[0011] The object of the present invention is achieved by the covering layer according to claim 1, the decorative component including such a covering layer according to claim 14, and the manufacturing method according to claim 15.

[0012] In its main aspect, the present invention relates to a cover for automotive trim components having a visible surface and comprising a porous fiber carrier layer and a polymeric thermoplastic matrix, wherein the polymeric thermoplastic matrix and the porous fiber carrier layer form a composite layer that forms the visible surface of the cover, wherein in the composite layer, the polymeric thermoplastic matrix encapsulates the fibers of the carrier layer and fills the pores between the fibers, and the porous fiber carrier layer remains visible from the visible surface of the cover through the polymeric thermoplastic matrix.

[0013] According to another aspect, the present invention relates to automotive trim components that include such a covering layer.

[0014] Surprisingly, it has been found that the cover layer according to the invention can have abrasion resistance, aging resistance, elongation, durability, and washability comparable to or even better than cover layers belonging to the prior art. Simultaneously, it provides an appearance essentially imparted by the random arrangement of fibers in a porous fiber carrier layer that remains visible through a polymeric thermoplastic matrix, presenting a natural and authentic textile appearance. Furthermore, any potential damage to the visible surface of the cover layer according to the invention (e.g., scratches) is less noticeable or not visible at all, as it is masked by the random distribution of fibers in the porous fiber carrier layer.

[0015] In this document, a "layer" is a substance composed of one or more materials and contained between two closely spaced surfaces, wherein the distance between the surfaces is much smaller than their dimensions. These two surfaces are referred to as the "faces" of the layer, and they are opposite each other. The distance between the two surfaces is represented as the thickness of the layer, which can be variable.

[0016] A “porous fiber layer” is a layer composed of fibers with gaps between them, the size of which is much smaller than the length of the fibers. These gaps are referred to as “pores” in this paper.

[0017] The porous fiber "carrier" layer is a self-supporting porous fiber layer that provides dimensional and mechanical stability for the capping layer of this invention.

[0018] A "composite layer" is a layer composed of composite materials. Composite materials are materials obtained by heterogeneous mixtures of two or more components (the "components" of a composite material) with different physical and / or chemical properties. A common example of composite materials is concrete, in which loose stones are bound together by a cementitious matrix. Other common examples of composite materials are carbon fiber reinforced plastics (CFRP) and glass fiber reinforced plastics (GFRP).

[0019] In the cover layer according to the invention, a composite layer is formed on the visible surface of the cover layer by a polymer thermoplastic matrix and a porous fiber carrier layer, wherein the polymer thermoplastic matrix completely encapsulates the fibers and fills the pores between the fibers.

[0020] In this overlay, the polymeric thermoplastic matrix provides abrasion and wash resistance while maintaining the visibility of the porous fiber carrier layer. Simultaneously, the porous fiber carrier layer visible through the polymeric thermoplastic matrix gives the overlay a natural and authentic textile appearance, while ensuring good dimensional stability and mechanical properties, particularly elongation and tensile strength, due to the fiber properties.

[0021] To ensure good washability, it is important that, within the composite layer according to the invention, the polymer thermoplastic matrix completely encapsulates the fibers of the porous fiber layer and fills the pores between the fibers, making the layer completely impermeable to gases and liquids under typical temperature / pressure conditions in passenger vehicles.

[0022] Therefore, the composite layer according to the invention achieves a synergistic effect between the polymer thermoplastic matrix and the porous fiber carrier layer, both of which contribute to the aesthetic appearance of the cover and its performance related to its use, such as abrasion resistance, elongation, tear strength, durability and washability.

[0023] Surprisingly, the cover layer according to the invention can be achieved with a very limited thickness. Preferably, the thickness of the cover layer according to the invention is 1 mm to 8 mm, more preferably 2 mm to 6 mm, and even more preferably 2 mm to 4 mm. This thickness range ensures that the packaging space occupied by the cover layer according to the invention is comparable to or even less than that of the cover layer according to the prior art.

[0024] The visible composite layer according to the invention, formed from a polymer thermoplastic matrix and a porous fiber layer and constituting the cover layer according to the invention, may comprise the entire porous fiber carrier layer and thus substantially correspond to the cover layer according to the invention. However, the composite layer according to the invention preferably comprises only a portion of the porous fiber carrier layer and therefore covers only a portion of the total thickness of the cover layer according to the invention. In fact, increasing the thickness of the composite layer can lead to improvements in some properties (e.g., abrasion resistance or durability) associated with using the cover layer according to the invention. However, increasing the thickness of the composite layer beyond a certain level yields only negligible performance improvements at the cost of greater processing difficulty and greater material consumption for the polymer thermoplastic matrix. Furthermore, the exclusion of certain portions of the porous fiber carrier layer from the composite layer according to the invention can result in improved sound insulation guaranteed by the cover layer.

[0025] Preferably, at least 10%, more preferably at least 40%, and even more preferably at least 70% of the thickness of the porous fiber carrier layer is not included in the composite layer according to the invention.

[0026] The composite layer according to the invention may include a sublayer composed solely of a polymeric thermoplastic matrix on the visible surface of the cover layer according to the invention. This surface sublayer can help improve some properties of the cover layer according to the invention, such as wash resistance and durability. However, it may reduce the visibility of the porous fiber carrier layer from the visible surface of the cover layer. When this surface sublayer is present in the composite layer according to the invention, its thickness is preferably less than 30% of the thickness of the cover layer according to the invention, more preferably less than 20%, and even more preferably less than 10%.

[0027] The visible side of the composite layer according to the invention, corresponding to the cover layer, is preferably not smooth to prevent the cover layer from having a glossy / glossy appearance (which is generally undesirable in the automotive industry). This effect can be achieved, for example, by giving the visible side of the composite layer according to the invention, corresponding to the cover layer, a textured or embossed design.

[0028] The porous fiber carrier layer can comprise any kind of natural and / or synthetic fiber commonly found in industry. Examples of natural fibers are cotton, wool, flax, hemp, bamboo, sisal, jute, coconut fiber, and Manila fiber. Examples of synthetic fibers are polypropylene fiber, polyethylene fiber, polyester fiber (e.g., terephthalate-based polyester fibers, such as polyethylene terephthalate (PET) fiber), polylactic acid (PLA) fiber, and polyamide (PA) fiber (especially polyamide 6 or polyamide 6.6 fiber). Synthetic fibers can be monocomponent or bicomponent. Monocomponent fibers are made from a single material, while bicomponent fibers are synthetic fibers made from two polymers with different chemical and / or physical structures, which are tightly bonded together along the fiber length. Bicomponent fibers can be produced using methods known in the art, such as by melt spinning. The porous fiber layer can consist of only one type of fiber, but it can also be a mixture of different types of fibers.

[0029] Advantageously, the fibers of the porous fiber carrier layer may at least partially possess recycling and / or regeneration properties to reduce the environmental impact of the manufacturing process of the cover according to the invention, particularly its CO2 footprint. Specifically, the porous fiber carrier layer may comprise fibers in the form of inferior natural fibers (e.g., inferior cotton) and / or fibers in the form of inferior synthetic fibers (e.g., inferior polyester). Inferior fibers are defined herein as recycled fibers containing at least 51% by weight of the relevant material. For example, inferior cotton contains at least 51% by weight of recycled cotton fibers, with the remaining 49% by weight consisting of fibers of different materials and / or virgin fibers.

[0030] Furthermore, the porous fiber carrier layer according to the invention preferably contains an adhesive, the amount of which is preferably from 10% to 50% by weight, or even more preferably from 20% to 40% by weight. The adhesive can be thermosetting or thermoplastic. In both cases, some form of heat treatment is required to activate it. Due to the adhesive, during the production process of the cover and / or decorative component according to the invention, the fibers of the porous fiber layer can be firmly bonded together along their entire length, while molding the cover and / or decorative component according to the invention into the desired shape. Thermosetting adhesives may be preferred when enhanced mechanical properties and structural stability are required. On the other hand, thermoplastic adhesive fiber adhesives may be preferred when very complex three-dimensional shapes must be achieved, and it is also advantageous for sustainability when the thermoplastic adhesive fibers and other fibers of the porous fiber carrier layer belong to the same chemical class (e.g., polyester).

[0031] Thermosetting adhesives are preferably in the form of epoxy resins or phenolic resins or mixtures of both. Thermoplastic adhesives are preferably in the form of thermoplastic adhesive fibers. These are fibers comprising at least a portion that melts due to heat treatment, forming a bond with all other fibers at their intersections / contact points. The melting temperature of the adhesive fiber (or the molten portion of the adhesive fiber) (also known as the “activation temperature” of the adhesive fiber) must obviously be lower than the melting temperature of all other fibers (and potentially non-melting portions of the adhesive fiber). The adhesive fiber can be a single-component fiber or a bicomponent fiber. Particularly preferred thermoplastic adhesive fibers are thermoplastic bicomponent core-sheath adhesive fibers. Thermoplastic bicomponent core-sheath adhesive fibers are bicomponent fibers in which one of the two components (sheath) surrounds the other (core). The sheath component is the fiber portion that melts during heat treatment as described above. In the bicomponent core-sheath adhesive fiber, the first polymer is preferably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), and the second polymer is preferably polyethylene terephthalate copolymer (coPET) or polybutylene terephthalate copolymer (coPBT).

[0032] The fibers contained in the porous fiber carrier layer may have a specific color to impart the desired hue or chromaticity to the visible surface of the cover layer according to the invention.

[0033] The fibers constituting the porous fiber carrier layer can be short fibers and endless fibers (commonly referred to as "filaments"). This also applies to the case where the porous fiber layer according to the invention may contain thermoplastic binder fibers. Unlike endless filaments, short fibers are fibers with discrete predetermined lengths. In particular, the short fibers contained in the porous fiber layer preferably have a length of 32 mm to 76 mm.

[0034] The fineness of the fibers constituting the porous fiber layer is preferably 0.5 denier to 25 denier, more preferably 0.5 denier to 16 denier, and even more preferably 0.5 denier to 12 denier.

[0035] The porous fiber carrier layer according to the present invention is preferably formed by the following steps: first, a nonwoven fiber layer in the form of a cushion and composed of fibers having the desired fiber composition (hereinafter referred to as "semi-finished product" or simply "semi-finished product") is prepared, and then it is molded under heat.

[0036] The production of the semi-finished product can be carried out according to any method known in the art. Such a method may specifically include a first step of forming a fibrous web composed of randomly oriented and unbonded fibers having a desired composition, and a second step of partially consolidating the fibrous web. In addition to these two steps, the production of the semi-finished product may also include other steps, such as carding and cross-laying, which may be considered to provide a specific preferred orientation for the fibers used to form the fibrous web.

[0037] A first process step for forming a fibrous web composed of randomly oriented and unbonded fibers with a desired composition can be performed using techniques known in the art (e.g., air-blowing, wet-blowing, spun web, meltblowing, and electrospinning). The main objective of this step is to obtain a mixture of randomly oriented, unbonded fibers with a desired composition, which is as homogeneous as possible.

[0038] The second process step for partially consolidating the aforementioned fibrous web can be performed using bonding techniques known in the art, such as thermal bonding, chemical bonding, mechanical bonding, or combinations thereof. Examples of thermal bonding are hot-calendering bonding and / or infrared heating bonding and / or ultrasonic bonding. Examples of chemical bonding are resin / powder coating bonding and / or foam bonding. Examples of mechanical bonding are needle punching and / or hydroentanglement. The main purpose of this partial consolidation step is to loosely bond the fibers of the fibrous web in the semi-finished product to each other, so that during the production process of the cover or decorative component according to the invention, only the stability required for handling is provided to the semi-finished product itself, while the semi-finished product retains a cushioned form. Therefore, the partially loose bonding of the fibers in the semi-finished product is very different from the completely firm bonding of the fibers that occurs during molding under heat of the porous fiber carrier layer.

[0039] The preferred area weight of the semi-finished product is 100g / m². 2 Up to 1600g / m 2 More preferably at 250g / m 2 Up to 1000g / m 2 , or even better, 400g / m 2 Up to 650g / m2 The thickness of the semi-finished material is preferably 1 mm to 15 mm, more preferably 2 mm to 10 mm, and even more preferably 4 mm to 7 mm.

[0040] In the cover layer according to the invention, a porous fiber carrier layer together with a polymer thermoplastic matrix forms a composite layer, which forms the visible surface of the cover layer itself, and wherein the thermoplastic matrix completely encapsulates the fibers of the porous fiber carrier layer and fills the pores between the fibers.

[0041] In addition, to achieve the desired effect, one or more materials of the polymeric thermoplastic matrix must ensure that the porous fiber carrier layer remains visible through the visible surface of the cover according to the invention. This can be achieved using optically transparent or translucent materials. Transparent materials allow light to pass through without significant scattering. When viewed through a transparent material, objects appear clear and have substantially defined shapes and boundaries. Translucent materials also allow light to pass through, but associated light scattering may occur when light passes through them. Therefore, when viewed through a translucent material, objects may appear blurry, with indistinct shapes and boundaries, but they are still visible.

[0042] The polymeric thermoplastic matrix can advantageously contain recycled polymeric materials to reduce the environmental impact of the manufacturing process of the coating according to the invention, particularly its CO2 footprint.

[0043] The polymeric thermoplastic matrix may contain colored pigments to impart the desired hue or chroma to the visible surface of the coating according to the invention. However, even with the addition of colored pigments to the polymeric thermoplastic matrix, it is crucial that the porous fiber carrier layer remains visible through the polymeric thermoplastic matrix itself.

[0044] The polymeric thermoplastic matrix according to the invention may comprise a thermoplastic polymer, such as a polyamide (e.g., polyamide 6 or polyamide 6.6), polypropylene, or a polyester (e.g., a terephthalate-based polyester (e.g., polyethylene terephthalate (PET)) or a copolymer of polyesters (e.g., a terephthalate-based polyester copolymer, such as polyethylene terephthalate copolymer (CoPET)) or polycarbonate (PC)). Other examples of thermoplastic polymers that can be used in the polymeric layer according to the invention are polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), polylactic acid (PLA), and polyhydroxyalkanoates (PHA).

[0045] Preferably, the porous fiber carrier layer and the polymer thermoplastic matrix belong to the same chemical class, which can benefit both the recyclability of production waste and the recyclability of the complete overlay and / or trim components according to the invention at the end of the vehicle's life. In a preferred embodiment, both the porous fiber carrier layer and the thermoplastic matrix are composed of polyester.

[0046] In a particularly preferred embodiment, the porous fiber carrier layer is composed of fibers made of PET and / or CoPET, and the polymer thermoplastic matrix is ​​composed of CoPET. This embodiment is particularly advantageous in terms of processability and recyclability.

[0047] In another particularly preferred embodiment, the porous fiber carrier is composed of fibers made of PET and / or CoPET, and the polymeric thermoplastic matrix is ​​composed of polycarbonate. This embodiment offers better durability compared to embodiments where the polymeric thermoplastic matrix is ​​composed of CoPET, although at the cost of a lower level of recyclability. Nevertheless, since polycarbonate and PET / CoPET belong to the polyester chemical family, even the level of recyclability in this embodiment can be considered acceptable in many applications.

[0048] The composite layer according to the present invention can be formed according to methods known in the art.

[0049] In a preferred embodiment, the composite layer according to the invention is formed by a method comprising at least the following three steps: depositing a polymeric thermoplastic material on the surface of a porous fiber layer, heating the polymeric thermoplastic material to soften and / or melt it and allow it to flow around the fibers of the porous fiber layer and penetrate between the fibers to fill the pores between the fibers, and finally cooling the polymeric thermoplastic material to harden it around the fibers and in the pores between the fibers, thereby forming the composite layer according to the invention.

[0050] In this preferred embodiment for forming the thermoplastic polymer matrix according to the invention, the amount of polymer material deposited on the surface of the porous fiber layer preferably results in an areal weight of 50 g / m². 2 Up to 1000g / m 2 More preferably 100g / m 2 Up to 500g / m 2 , or even better, 150g / m 2 Up to 300g / m 2 .

[0051] In this preferred embodiment, the deposition step can be performed according to any technique known in the art. For example, by dispersing a polymeric thermoplastic material in powder form on the surface of a porous fiber layer, or by laminating and / or extruding a polymeric thermoplastic material in layer or film form on the surface of a porous fiber material.

[0052] In a particularly preferred embodiment of this type, the deposition step includes dispersing CoPET powder on the surface of the porous fiber layer. The CoPET powder has a particle size preferably from 100 micrometers to 800 micrometers, more preferably from 200 micrometers to 700 micrometers, and even more preferably from 400 micrometers to 600 micrometers. In this embodiment, the melt flow index (MFI) of CoPET is preferably from 10 g / 10 min to 40 g / 10 min, more preferably from 15 g / 10 min to 30 g / 10 min, at 190°C and 1.6 kg. This combination of powder particle size and MFI within these ranges ensures that when the CoPET powder is softened by heat treatment, it can effectively flow around the fibers of the porous fiber layer and fill the pores of the fibers. In this embodiment, the melting temperature of CoPET is preferably from 120°C to 180°C, more preferably from 140°C to 170°C. These temperatures can be easily achieved using standard equipment used in the field.

[0053] In another particularly preferred embodiment of this type, the deposition step includes dispersing polycarbonate (PC) powder on the surface of the porous fiber layer. The PC powder has a particle size within the same range as the CoPET powder described above, but its melt flow index (MFI) is 10 g / 10 min to 40 g / 10 min, preferably 15 g / 10 min to 25 g / 10 min, at 300°C and 1.2 kg. This combination of particle size and MFI within these ranges ensures that when the polycarbonate powder is softened by heat treatment, it can effectively flow around the fibers of the porous fiber layer and fill the pores of the fibers. In this embodiment, the melting temperature of the polycarbonate is preferably 220°C to 320°C, more preferably 240°C to 280°C. These temperatures can be easily achieved using standard equipment used in the field.

[0054] The above embodiments represent only two examples, wherein the deposition step includes dispersing a polymeric thermoplastic material in powder form on the surface of a porous fiber layer. Other materials besides CoPET and polycarbonate can be used. Furthermore, the thermoplastic material can also be in a form other than powder. Depending on the thermoplastic material used and its form, the powder particle size and MFI range can be readily adjusted by those skilled in the art.

[0055] In addition to the porous fiber carrier layer and the thermoplastic matrix, the cover layer according to the present invention may also include other layers.

[0056] In one embodiment, the cover layer according to the invention includes a sound-insulating layer located on the side of the cover layer opposite to the visible surface. A "sound-insulating layer" is an airtight or impermeable layer, meaning it does not allow air to enter or exit, thereby hindering the propagation of sound waves. In the cover layer according to the invention, the function of the sound-insulating layer includes enhancing the sound insulation of the cover layer according to the invention.

[0057] When a particularly lightweight covering layer and / or decorative component according to the invention is required, the areal weight of the barrier layer is preferably 10 g / m². 2 Up to 200g / m 2 More preferably 50g / m 2 Up to 150g / m 2 Furthermore, the total area weight of the covering layer according to the present invention is 250 g / m². 2 Up to 1600g / m 2 Between, preferably 400g / m 2 Up to 1200g / m 2 Even better at 600g / m 2 Up to 1000g / m 2 In this case, a preferred embodiment of the barrier layer is a polymeric membrane, preferably comprising at least one polymer or copolymer selected from the group consisting of: polyesters such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT); polyamides such as polyamide 6 or polyamide 66; polyolefins such as polypropylene (PP) or polyethylene (PE); thermoplastic elastomers (TPEs) such as thermoplastic polyolefins (TPO) or thermoplastic polyurethanes (TPU); elastomers such as EPDM-based elastomers or butadiene-based elastomers or silicones; high-performance polymers such as polytetrafluoroethylene (PTFE), polyetherimide, polysulfone, polyethersulfone, or polyetheretherketone (PEEK); ethylene vinyl acetate (EVA); and biopolymers such as polylactic acid (PLA).

[0058] Preferably, one or more materials used in the membrane and one or more materials used in the porous fiber carrier layer and / or the polymer thermoplastic matrix belong to the same chemical class, which facilitates recycling. The membrane can be single-layer, bilayer, or multilayer. Bilayer or multilayer membranes can be used to further increase stability, elasticity, and / or robustness.

[0059] On the other hand, when a covering layer with particularly enhanced sound insulation is required, the areal weight of the barrier layer is preferably 500 g / m². 2 Up to 8000g / m 2 More preferably 1500g / m 2 Up to 5000g / m 2 , or even better, 2000g / m 2 Up to 3500g / m 2In this case, the total area weight of the covering layer according to the invention is 600 g / m². 2 Up to 10000g / m 2 More preferably 2000g / m 2 Up to 6000g / m 2 Even better at 2500g / m 2 Up to 4000g / m 2 .

[0060] In this context, a preferred embodiment of the sound insulation layer comprises a layer of thermoplastic elastic material matrix loaded with a large amount of inorganic filler. Such a layer is commonly referred to in the art as a "heavy layer," and is airtight, thus making it suitable as a barrier layer in the covering layer according to the invention. In this embodiment of the sound insulation layer, one or more materials included in the thermoplastic elastomer matrix are preferably selected from the group consisting of: ethylene vinyl acetate copolymer (EVA); ethylene propylene diene monomer (EPDM); polyester, such as polyethylene terephthalate (PET) and / or polybutylene terephthalate (PBT); polypropylene (PP); polyethylene, such as high-density polyethylene (HDPE) and / or low-density polyethylene (LDPE) and / or ultra-high molecular weight polyethylene (UHMWPE); polyvinyl chloride (PVC); polycarbonate (PC); polyamide, such as PA-4 and / or PA-11 and / or PA-12 and / or PA-6 and / or PA-66; thermoplastic polyamide (TPI); thermoplastic polyolefin (TPO); thermoplastic polyurethane (TPU); polytetrafluoroethylene (PTFE); polyether ether ketone (PEEK); acrylonitrile butadiene styrene (ABS); polymethyl methacrylate (PMMA). The inorganic filler is preferably one of calcium carbonate (CaCO3) and / or barium sulfate (BaSO4). Furthermore, the amount of inorganic filler is preferably up to about 85% by weight.

[0061] In this embodiment of the sound insulation layer, the thickness of the sound insulation layer is preferably 0.2 mm to 5 mm, more preferably 0.8 mm to 2.5 mm.

[0062] The choice of sound insulation layer (in particular its area weight and material) can depend on the desired trade-off between the sound insulation capability and the total weight of the covering layer according to the invention.

[0063] Preferably, in the covering layer according to the invention, the porous fiber carrier layer and the sound-insulating layer are adjacent to each other and are laminated together. In this context, "laminated together" means that they are permanently assembled together in such a way that they function under the impact of sound waves striking the sound-attenuating decorative component according to the invention. The lamination process can be carried out, for example, by heating and / or pressurizing and / or welding and / or bonding.

[0064] When the sound insulation layer and the porous fiber carrier layer consist of materials belonging to the same chemical category, the lamination process can be easier.

[0065] In addition to the cover layer according to the invention, the decorative component according to the invention may also include other layers, such as a spring layer and / or a sound-absorbing layer and / or a decorative backing layer. These additional layers are located on the side of the cover layer opposite to the visible surface, i.e., when the component is in use, they are located between the cover layer and the vehicle body.

[0066] When using the decorative component according to the invention, the spring layer is a layer located between the cover layer according to the invention and the vehicle body, and it functions to isolate the cover layer according to the invention from vehicle body vibrations, thereby enhancing the sound insulation performance of the decorative component according to the invention. To achieve this function, the spring layer must be arranged such that vibrations from the vehicle body can be efficiently transmitted to it. To achieve this, in some embodiments, the side of the spring layer opposite to the side facing the cover layer can at least partially contact the vehicle body. However, this is not essential for the spring layer to properly perform its function.

[0067] Preferably, the spring layer has a dynamic compressive Young's modulus of not more than 300 kPa, more preferably not more than 150 kPa, and even more preferably not more than 80 kPa. Furthermore, the spring layer has a variable thickness, preferably from 1 mm to 80 mm, more preferably from 3 mm to 50 mm, and even more preferably from 5 mm to 40 mm. Generally, a lower dynamic compressive Young's modulus and a higher thickness can provide better performance, i.e., the spring layer better isolates the cover layer from vibrations of the vehicle body. However, in practice, the thickness of the spring layer can be limited by design constraints, such as packaging space or cost.

[0068] The dynamic compressive Young's modulus of the spring layer can be measured using the commercially available Elwis-S tool sold by Autoneum Management AG. The standard test for the Elwis-S system is performed on a flat, circular sample with a diameter of 100 mm. However, if a suitable flat sample with such a diameter cannot be extracted from the decorative component, the test can also be performed on a sample with a smaller diameter. Preferably, the sample diameter should be at least 60 mm. Furthermore, the load mass used for the Elwis-S test should be such that it ensures the sample under test is properly loaded and subjected to uniform force across its entire surface. For performing the test with a standard circular sample with a diameter of 100 mm, a load mass of 150 g to 400 g is preferred. For tests performed using circular samples with different diameters, the top load mass should be readjusted according to the sample surface. Preferably, the dynamic compressive Young's modulus in Elwis-S units is obtained by averaging within the frequency range optimal for this measurement system (e.g., 300 Hz to 700 Hz).

[0069] The spring layer can comprise any material, as long as it fulfills the aforementioned primary functions. Preferably, it comprises porous and / or cellular materials, which is advantageous in terms of weight reduction.

[0070] In a first embodiment, the spring layer according to the invention comprises a porous fiber layer. In this embodiment, one or more fiber materials used for the spring layer can be substantially the same as those used for the porous fiber carrier layer described above according to the invention. However, in this embodiment, the spring layer preferably has a lower density than the porous fiber carrier layer according to the invention; that is, it is preferably more loftier and less compressible, as this helps to enhance its isolation function against vehicle body vibrations. In this embodiment, the density of the spring layer is preferably 30 kg / m³. 3 Up to 250kg / m 3 More preferably 40kg / m 3 Up to 200kg / m 3 , or even better, 50kg / m 3 Up to 150kg / m 3 This first embodiment of the spring layer can offer advantages in terms of end-of-life recyclability of the sound-attenuating decorative component according to the invention, particularly when one or more materials of the spring layer belong to the same chemical class as one or more materials of the sound-insulating layer and / or the porous fiber carrier layer and / or the polymer thermoplastic matrix.

[0071] In a second embodiment, the spring layer according to the invention is composed of open-cell foam, preferably polyurethane foam. In this embodiment, the foam density is preferably 30 kg / m³. 3 Up to 200kg / m 3 More preferably 40kg / m 3 Up to 120kg / m 3 , or even better, 50kg / m 3 Up to 90kg / m 3 This implementation of the spring layer can be advantageous because foam (especially polyurethane foam) offers excellent molding possibilities and greater design flexibility. Therefore, this embodiment can be advantageous if the decorative component according to the invention is to be fitted onto a vehicle body panel with a particularly complex three-dimensional shape.

[0072] A sound-absorbing layer is a layer that, when used in a component, is positioned between the overlay according to the invention and the vehicle body, and has the function of absorbing sound waves radiated by the vehicle body, thereby enhancing the sound insulation performance of the decorative component according to the invention. To achieve its function, the sound-absorbing layer must be arranged such that its side opposite the side facing the overlay is at least partially exposed to sound waves radiated by the vehicle body. In some embodiments, this is achieved by leaving an air gap between the vehicle body and said side of the sound-absorbing layer.

[0073] The sound-absorbing layer can comprise any material, as long as it fulfills the aforementioned primary functions. Preferably, it comprises porous and / or honeycomb materials, which is advantageous in terms of weight reduction.

[0074] Preferably, the air flow resistance (AFR) of the sound-absorbing layer is 300 Ns / m. 3 Up to 6000 Ns / m 3 More preferably 600 Ns / m 3 Up to 4000 Ns / m 3 Even more preferred is 1000 Ns / m 3 Up to 2500 Ns / m 3 The AFR is measured according to ISO 9053-1:2018. Furthermore, the spring layer has a variable thickness, preferably from 1 mm to 80 mm, more preferably from 3 mm to 50 mm, and even more preferably from 5 mm to 40 mm.

[0075] In a first embodiment, the sound-absorbing layer according to the invention comprises a porous fiber layer. One or more materials that can be used in the sound-absorbing layer according to this first embodiment are the same as those already mentioned for the first embodiment of the spring layer.

[0076] In a second embodiment, the sound-absorbing layer according to the invention is composed of an open-cell foam structure. One or more materials that can be used in the sound-absorbing layer according to this second embodiment are the same as those materials already mentioned for the second embodiment of the spring layer.

[0077] In some embodiments, to enhance its sound absorption performance, the sound-absorbing layer may comprise a thin, porous fibrous layer (commonly referred to in the art as "sparse cloth") or a microporous foil with a tuned flow resistivity (AFR), laminated on the side of the sound-absorbing layer opposite to the side facing the cover layer according to the invention. To achieve the desired improvement in the sound absorption performance of the sound-absorbing layer, the AFR of the sparse fibrous cloth or microporous polymer foil is preferably at least 50% of the total AFR of the sound-absorbing layer, and more preferably at least 75% in all areas where the sparse fibrous cloth or microporous membrane is applied. The areal weight of the sparse fibrous cloth or microporous polymer foil is preferably no more than 400 g / m². 2 More preferably not exceeding 200 g / m2 So as not to significantly increase the total weight of the decorative component according to the invention.

[0078] A decorative backing layer is a layer that, when the component is in use, covers the side of the decorative component opposite to the cover layer, that is, the side facing the vehicle body when the component is in use. When viewed from the same side, this decorative layer serves to improve the appearance of the decorative component according to the invention. This can be relevant to the case of removable components (e.g., trunk floor covers).

[0079] For decorative backing, any material in the art used for the aforementioned decorative purposes may be used. Examples include loosely woven fabric, needle-punched carpet, or tufted carpet.

[0080] Those skilled in the art can advantageously combine all the preferred embodiments of the overlay, elastic layer, sound-absorbing layer and decorative backing layer listed above, where technically possible and deemed advantageous, based on the desired trade-offs between in-vehicle sound quality, weight, manufacturing complexity and design constraints.

[0081] The covering layer according to the invention can be manufactured using tools and techniques known in the art.

[0082] A first method of producing a cover layer according to the invention, suitable for situations where a layered structure is included in the cover layer to improve sound insulation, may include at least the following steps: (a1) A porous fibrous layer in semi-finished form, comprising an adhesive (e.g., thermoplastic two-component core-sheath adhesive fiber), is provided on a horizontal support surface (e.g., a workbench or conveyor belt). A thermoplastic material in powder form is dispersed on its top surface. This is the visible side of the coating according to the invention at the end of the process. As is known in the art, dispersion can be performed by hand or using an automatic disperser.

[0083] The particle size of the thermoplastic material in powder form is preferably similar to or larger than the typical pore size of the porous fiber layer, so that when the thermoplastic material is dispersed on the porous fiber layer, it remains mainly on the surface of the same porous fiber layer and does not penetrate into it in large quantities.

[0084] The powder is preferably spread in a sufficient amount to cover the porous fiber layer as uniformly as possible. For semi-finished layers with considerably irregular surfaces (e.g., semi-finished layers obtained by air-laid processes), more powder may be required to ensure good, uniform coverage. For carded, needle-punched, or calendered semi-finished layers, less powder may be sufficient due to the more regular surfaces of these porous fiber layers.

[0085] (a2) One side of the porous fiber layer on which thermoplastic powder is dispersed is exposed to a heat source, such as an infrared (IR) heater. The exposure time and temperature of the heat source should be adjusted to soften or even melt the thermoplastic material in powder form as much as possible, while preventing such material from beginning to flow extensively around the fibers of the porous fiber layer and into the pores between the fibers. This can be achieved by adjusting the exposure time and heat source temperature according to parameters such as the amount of thermoplastic material, its softening and melting temperatures, and its melt flow index.

[0086] (a3) A porous fiber layer with a softened thermoplastic material on its top surface is passed through a pair of nip-rollers that are cooled or at least kept at room temperature, wherein the gap between the rolls is much smaller than the thickness of the porous fiber layer (e.g., one-fifth to one-third of the thickness of the porous fiber layer). Passing through the rolls (at room temperature or even lower, while they are cooled) will harden the thermoplastic material and adhere it to the porous fiber layer, while spreading it uniformly over the surface of the porous fiber layer itself. The result of this step is that the porous fiber layer is uniformly covered by a thin layer of thermoplastic material with a smooth surface (i.e., much thinner than the porous fiber layer). In this step, the thickness of the porous fiber layer remains substantially unchanged. Furthermore, the thin layer of thermoplastic material produced by this process step, while adhering to and uniformly covering the porous fiber layer, remains essentially on its surface with minimal penetration into the pores between its fibers.

[0087] (a4). A heavy layer is provided and arranged on the bottom surface of the porous fiber layer, that is, on the side opposite to the side covered by the thin layer of thermoplastic material.

[0088] (a5) Place the multilayer consisting of a thin thermoplastic layer, a porous fiber layer, and a heavy layer into a hot press. Set the gap of the hot press to be much smaller than the thickness of the multilayer, for example, one-quarter to one-half of it. Adjust the temperature of the press top plate (i.e., the plate in contact with the thin thermoplastic layer) to soften the thermoplastic. At the same time, set the temperature of the press top plate to be higher than the activation temperature of the adhesive contained in the porous fiber layer. On the other hand, set the temperature of the press bottom plate to be higher than the softening point of the heavy layer, but lower than its melting point.

[0089] The multiple layers are then held inside the hot press for at least a sufficient period of time to achieve the following effect: - Due to compression in the hot press, the softened thermoplastic material flows around the fibers of the porous fiber layer and enters the pores between them; - Due to compression in the hot press, the re-layer adheres to the side of the porous fiber layer opposite to the side where the original powdered thermoplastic material was dispersed; - Activate the adhesive contained in the porous fiber layer (e.g., melt the skin of the thermoplastic two-component adhesive fiber).

[0090] The time within the hot press can be adjusted by those skilled in the art based on the amount of thermoplastic material and its melt flow index, as well as the area weight / thickness of the porous fiber layer and the type / amount of adhesive contained therein.

[0091] (a6) After sufficient time to achieve all the above effects, the multilayer is removed from the hot press and placed in a cold molding tool comprising a lower mold and an upper mold, which, when the molding tool is closed, define a cavity having the required three-dimensional shape of the cover layer according to the invention. In this document, "cold molding tool" refers to a tool in which the upper and lower molds are not actively heated during the molding operation.

[0092] (a7) Due to the hardening of the thermoplastic material and adhesive contained in the porous fiber layer, the molding tool is closed and held closed for a sufficient period of time to allow the cover layer to take on and maintain the desired shape. In this step, the polymeric thermoplastic material hardens around and in the pores between the fibers of the porous fiber layer, thereby forming the polymeric thermoplastic matrix and composite layer according to the invention. Simultaneously, this process step imparts its "carrier" function to the porous fiber layer: due to the presence and compression of the adhesive, the porous fiber layer becomes rigid and self-supporting, thereby providing dimensional and mechanical stability to the cover layer of the invention. Furthermore, the compression in the molding tool can also force the thermoplastic material to flow around and in the pores between the fibers of the porous fiber layer, thereby further increasing the thickness of the composite layer according to the invention. If desired, in this step, the semi-molded surface facing the visible surface of the cover layer can be treated as known in the art to impart a visible texture or embossed design to the cover layer according to the invention.

[0093] (a8). After sufficient time for the cover layer to take shape and maintain the desired form, open the molding tool and remove the cover layer according to the invention from it.

[0094] In a second production method applicable to situations requiring a particularly lightweight cover layer, step (a4) can be omitted, or in this step, a polymer film can be used instead of the heavy layer. As those skilled in the art will know, when doing so, steps (a5) to (a8) should be adjusted accordingly.

[0095] The methods described above for manufacturing the cover layer according to the invention represent only two examples. Variations of these methods are possible and can be readily appreciated by those skilled in the art, in which different types of tools and / or other steps are intended to improve, for example, the flow of thermoplastic materials in the pores of porous fibrous materials.

[0096] Furthermore, decorative components according to the present invention and including the covering layer according to the present invention can also be easily obtained through extensions or variations of the above methods.

[0097] For example, a decorative component consisting of a cover layer and a spring layer (wherein the spring layer is composed of open-cell foam) according to the invention can be obtained by taking the cover layer according to the invention produced by step (a8) and back-foaming it using a foaming tool, so as to obtain a foam spring layer on the side of the cover layer opposite to the visible surface.

[0098] Similarly, as is known to those skilled in the art, decorative components according to the present invention, including a sound-absorbing layer and / or a porous fiber spring layer, can be obtained by including such layers in a stack introduced into a hot press in step (a4) and modifying steps (a5) to (a8) accordingly.

[0099] All embodiments previously described for the cover and / or decorative components according to the invention represent only possible material arrangements. By taking into account the characteristics of the materials described herein, particularly their properties, density, thickness, and areal weight, those skilled in the art can deduce other material arrangements that may be suitable depending on the circumstances, based on these embodiments.

[0100] In addition, other embodiments of the covering and decorative components according to the invention can be derived from this specification by combining different embodiments and examples of the invention, and also from the description of the embodiments shown in the accompanying drawings. The drawings are schematic and not necessarily to scale. All disclosed scopes include endpoints. Attached Figure Description

[0101] Figure 1 and 2 Two examples of the overlay layer according to the present invention are shown.

[0102] Figures 3a to 3i A method for producing the cover layer according to the present invention is shown.

[0103] Figure 1 An example of a cover layer 1 according to the invention is shown, comprising a porous fiber carrier layer 2 and a polymer thermoplastic matrix 3, which form a composite layer 5 comprising a visible surface 4 of the cover layer 1. In this composite layer 5, the polymer thermoplastic matrix 3 encapsulates the fibers and fills the pores between the fibers. It should be noted that the porous fiber carrier 2 includes fibers included in the composite layer 5 and fibers not included in such a layer, such as... Figure 1 As indicated by the arrows, the porous fiber carrier layer remains visible through the polymer thermoplastic matrix. Figure 1In the example shown, composite layer 5 does not cover the entire thickness of cover layer 1. In this example, approximately 50% of the porous carrier layer thickness is not included in composite layer 5.

[0104] Figure 2 Another example of a cover layer 10 according to the invention is shown, which further includes a secondary layer 6 on the side opposite to the visible surface 4.

[0105] According to the covering layer of the present invention Figures 3a to 3i The production process is carried out according to the steps shown. The porous fiber layer 20 is placed on the support conveyor belt 21 (see...). Figure 3a The porous fiber layer 20 is in the form of a semi-finished product, with a density of approximately 600 g / m³. 2 It has an area weight and a thickness of about 8 mm, and it comprises the following fiber mixture: 38% by weight of inferior PET fiber, 30% by weight of inferior cotton fiber and 32% by weight of PET / CoPET core-sheath adhesive fiber with an activation temperature of about 120°C.

[0106] like Figure 3a As shown, polycarbonate powder 23 is dispersed on top of the porous fiber layer 20 by an industrial disperser 22 in such a way that the powder particles 24 cover the surface of the porous fiber layer 20 as uniformly and evenly as possible. A total of 200 g / m³ is dispersed. 2 Polycarbonate powder 23 is dispersed on top of porous fiber layer 20. The particle size of the polycarbonate powder is 400 to 600 micrometers. The polycarbonate used has a melting temperature of about 255°C and an MFI of 22 g / 10 min at 300°C and 1.2 kg.

[0107] The porous fiber layer with polycarbonate powder scattered on top is exposed to the IR heater 25 (see Figure 3c The temperature of the IR heater 25 is approximately 220°C, and the exposure time is approximately 30 seconds. This softens the polycarbonate powder particles 24, but does not cause the polycarbonate to begin flowing around the fibers of the porous fiber layer 20 and into the pores between them.

[0108] After that, as Figure 3c As shown, a porous fiber layer 20, topped with softened polycarbonate powder 24, is passed between two rollers 26 at room temperature. The gap between the rollers is approximately 1.8 mm. Passing through the small gap between the rollers at room temperature forces the polycarbonate layer to be spread uniformly on the surface of the porous fiber layer while simultaneously hardening it. The result of this step is that the porous fiber layer is uniformly covered by a thin layer 27 of polycarbonate with a smooth surface (i.e., much thinner than the porous fiber layer).

[0109] Then (see) Figure 3dIt provides EPDM composed of a large amount of inorganic filler, with a thickness of approximately 1.8 mm and an area weight of approximately 3 kg / m². 2 The heavy layer 28 is arranged on the bottom surface of the porous fiber layer 20, opposite to the side covered by the polycarbonate thin layer 27. The multilayer 29, consisting of the polycarbonate thin layer 27, the porous fiber layer 20, and the heavy layer 28, is then placed in a hot press 30 including a top plate 31 and a bottom plate 32. The hot press is then shut down (see...). Figure 3e The gap is set to approximately 2.5 mm. The temperature of the top plate 31 is set to 215°C, and the temperature of the bottom plate 32 is set to approximately 70°C. The multilayer 29 is placed in the hot press 30 for approximately 50 seconds. The selected temperature of the top plate (i.e., the surface in contact with the polycarbonate layer) softens the polycarbonate layer 27. At the same time, the temperature of the top plate 31 is set higher than the activation temperature of the adhesive contained in the porous fiber layer 20. On the other hand, the temperature of the bottom plate 32 of the hot press is set higher than the softening point of the heavy layer 28, but lower than its melting point.

[0110] The duration of this compression step within the hot press was empirically adjusted through a limited number of experiments to achieve the effects mentioned earlier: - Soften the polycarbonate as it flows around the porous fiber layer and into the pores between them; - The relayer adheres to the porous fiber layer; - The adhesive contained in the porous fiber layer is activated.

[0111] After that, as Figure 3f and 3g As shown, open the hot press 30 and place the multi-layer 29 into the cold molding tool 33, which has an upper mold 34 and a lower mold 35. Close the cold molding tool 33 (see...). Figure 3h Keep it closed for approximately 45 seconds. After that, open it (see...). Figure 3i ), and remove the cover layer 40 according to the invention from the cold molding tool 33.

[0112] Wear and elongation tests were performed on the coating obtained according to the invention as described in the preceding paragraphs. Elongation tests were performed on five samples extracted from the coating according to the invention according to ISO 527-2:2012. The test samples were 170 mm × 25 mm in size, with a clamping distance of 100 mm and a preload of 5 N. Two quantities were evaluated: Young's modulus in the longitudinal direction (the most relevant direction for this type of test) and tensile strength. The results showed a Young's modulus of 388 MPa ± 53 MPa and a tensile strength of 10.22 MPa ± 0.62 MPa, where the values ​​shown are the average of the five samples, and the uncertainties shown are the standard deviations.

[0113] Wear tests were performed on two circular samples with a diameter of 108 mm extracted from the coating according to the invention using a Taber 5155 rotary abrasion tester. The initial weight of the first sample was 33.801 g, and the initial weight of the second sample was 33.105 g. For these wear tests, an H22 wheel was used at a speed of 60 rpm, a load of 10 N, and a vacuum cleaner power of 80%. The wheel was cleaned with a brush after 200, 500, and 800 rpm. The results showed that after 1000 rpm, the weight reduction of the first sample was only 0.033 g, while the weight reduction of the second sample was only 0.020 g.

[0114] For comparative purposes, the same type of test was performed on samples taken from the overlay of a prior art trim component (a floor carpet barrier for Class B European commercial vehicles), which consists of a TPO layer backed with an EPDM layer and has a strength of approximately 3.6 kg / m³. 2 The area weight is therefore comparable to that of the cover layer according to the invention. Elongation tests on five samples showed a longitudinal Young's modulus of 195 MPa ± 18 MPa and a tensile strength of 3.17 MPa ± 0.12 MPa. Both values ​​are significantly lower than those obtained with the cover layer according to the invention. Abrasion tests on two samples with initial weights of 32.359 g and 32.269 g showed a weight loss of 0.074 g after 1000 revolutions, which is significantly higher than the weight loss obtained with the cover layer according to the invention.

[0115] These results demonstrate that, compared to existing cover layers, the cover layer according to the present invention provides better ductility and abrasion resistance.

Claims

1. A cover layer for automotive trim parts (1, 10, 40), having a visible surface (4) and comprising a porous fiber carrier layer (2) and a polymer thermoplastic matrix (3), characterized in that The polymer thermoplastic matrix (3) and the porous fiber carrier layer (2) form a composite layer (5), the composite layer (5) forming the visible surface (4) of the cover layer, wherein in the composite layer (5), the polymer thermoplastic matrix (3) wraps the fibers of the porous fiber carrier layer (2) and fills the pores between the fibers, and wherein the porous fiber carrier layer (2) is visible through the polymer thermoplastic matrix (3) from the visible surface (4) of the cover layer.

2. The covering layer for automotive trim components according to claim 1, characterized in that... At least 10%, preferably at least 40%, and even more preferably at least 70% of the thickness of the porous fiber carrier layer is not included in the composite layer.

3. The covering layer for automotive trim components according to claim 1 or 2, characterized in that... The porous fiber carrier layer comprises at least one natural fiber, such as cotton fiber, and synthetic fibers, such as polyester fiber, polypropylene fiber, and polyamide fiber.

4. The covering layer according to any one of the preceding claims, characterized in that, The porous fiber carrier layer contains fibers with recyclable and / or regenerable properties.

5. The covering layer according to any one of the preceding claims, characterized in that... The polymer thermoplastic matrix comprises at least one polyester, preferably a terephthalate-based polyester, more preferably polyethylene terephthalate (PET), a copolymer of terephthalate-based polyesters, preferably a copolymer of polyethylene terephthalate (CoPET), polycarbonate (PC), polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), polylactic acid (PLA), and polyhydroxyalkanoate (PHA).

6. The covering layer according to any one of the preceding claims, characterized in that... It also includes a sound-insulating layer on the side opposite the visible layer.

7. The covering layer according to any one of the preceding claims, characterized in that... The composite layer (5) is formed by a method comprising at least the following three steps: - Disperse a polymeric thermoplastic material in powder form on the surface of a porous fiber layer; - The polymer thermoplastic material is softened or melted by heat treatment, causing it to flow around the fibers of the porous fiber layer and penetrate between the fibers to fill the pores between the fibers; - Cool the polymer thermoplastic material to harden it.

8. The covering layer according to claim 7, characterized in that... The powdered thermoplastic material includes polyester copolymers, preferably copolymers of polyesters based on terephthalate, and even more preferably copolymers of PET (CoPET).

9. The covering layer according to claim 8, characterized in that... The particle size of the thermoplastic material in powder form is 100 micrometers to 800 micrometers, more preferably 200 micrometers to 700 micrometers, and even more preferably 400 micrometers to 600 micrometers.

10. The covering layer according to claim 8 or 9, characterized in that... The copolymer of the polyester has a melt flow index of 10 g / 10 min to 40 g / 10 min, more preferably 15 g / 10 min to 30 g / 10 min, at 190 °C and 1.6 kg.

11. The covering layer according to claim 7, characterized in that... The powdered thermoplastic material includes polycarbonate.

12. The covering layer according to claim 11, characterized in that... The particle size of the thermoplastic material in powder form is 100 micrometers to 800 micrometers, more preferably 200 micrometers to 700 micrometers, and even more preferably 400 micrometers to 600 micrometers.

13. The covering layer according to claim 11 or 12, characterized in that... The polycarbonate has a melt flow index of 10 g / 10 min to 40 g / 10 min, preferably 15 g / 10 min to 25 g / 10 min, at 300 °C and 1.2 kg.

14. An automotive trim component comprising the cover layer according to claim 1.

15. A method for producing the cover layer according to claim 1, comprising at least the following steps: (a1). A porous fiber layer, preferably in the form of a semi-finished product, is provided, and a polymer thermoplastic material in the form of powder is dispersed on one side thereof; (a2) Expose the surface on which the polymeric thermoplastic material in powder form is dispersed to a heat source to soften the polymeric thermoplastic material; (a3) Pass a porous fiber layer with a softening thermoplastic material onto a pair of rollers, wherein the gap between the rollers is less than the thickness of the porous fiber layer, preferably less than one-third of the thickness of the porous fiber layer, so that the thermoplastic material forms a thin layer on the surface of the porous fiber layer where the powder is initially dispersed. (a4). A multilayer consisting of the porous fiber layer and the thin polymer thermoplastic layer is placed in a hot press and the press is turned off for a period of time, which is sufficient to allow the polymer thermoplastic material to soften and flow around the fibers of the porous fiber layer and into the pores around the fibers; (a5). Open the hot press and transfer the multilayer to a cold molding tool having an upper mold and a lower mold; (a6). Turn off the cold molding tool and keep it off for a period of time sufficient for the multilayer to be presented and to maintain the desired shape of the cover layer; (a7). Open the cold molding tool and remove the cover layer therefrom.

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