Cover layer for visible work surface of automotive trim parts

Abstract

A cover layer for an automotive trim part comprising a porous fiber carrier layer and a thermoplastic polymer matrix, wherein the thermoplastic polymer matrix and the porous fiber carrier layer form a composite layer that forms the visible side of the cover layer. In the composite layer, the thermoplastic polymer matrix encloses the fibers of the carrier layer, fills the pores between the fibers, and makes the porous fiber carrier layer visible from the visible side of the cover layer through the thermoplastic polymer matrix itself.

Description

[Technical Field]

[0001] The present invention relates to the field of automotive trim parts that are installed in the interior and / or exterior of road vehicles. [Background technology]

[0002] Many automotive trim components are visible to the vehicle's occupants and users, yet they also have surfaces that can experience significant wear and tear throughout the vehicle's lifespan. Typical examples of such trim components include trunk floor covers or passenger compartment floor covers (including floor mats), particularly in vans, SUVs, pickups, and light commercial vehicles.

[0003] Typically, the visible working surfaces of these parts are formed by cover layers that may need to perform different functions. On the one hand, the cover layers may help to achieve a desired appearance, such as a particular shade, texture, or surface pattern. On the other hand, the same cover layers may serve to protect the parts from external mechanical stresses, such as impacts and scratches caused by friction applied by, for example, the feet of occupants and / or objects during loading and unloading of cargo. In addition, the cover layers may also serve to protect the parts from the penetration of moisture or liquids, particularly in areas that require regular cleaning and / or washing, such as the cargo area, especially in vans and / or pickup trucks and / or light commercial vehicles.

[0004] To perform all the functions described above, the cover layers that automakers use on the visible surfaces of automotive trim parts have evolved over time to have fairly complex structures and contain different types of materials. These are typically arranged in a multilayer structure, with each layer of the multilayer having a specific function. Typical materials used in each of these layers are polymer materials such as TPO and / or EPDM and / or RIM-PU, sometimes combined with thin nonwoven fabrics.

[0005] For example, Chinese Patent No. 208914720 discloses a vehicle carpet comprising a cover layer consisting of an EPDM layer and a TPO layer provided on the upper surface of the EPDM layer. The TPO layer includes a TPO base layer, a coating layer printed on the TPO base layer and having color and / or texture, and a transparent layer laminated on the upper surface of the coating layer. Furthermore, a thin fibrous nonwoven fabric layer may be optionally added to the underside of the EPDM layer. According to the disclosure of Chinese Patent No. 208914720, the transparent layer mainly serves to protect the printed coating layer from abrasion, and the printed coating layer, in turn, is mainly responsible for the visible appearance of the part. Consistently according to the disclosure of Chinese Patent No. 208914720, the EPDM layer serves to enhance the sound insulation of the cover layer, while the thin fibrous nonwoven fabric layer (if present) serves to absorb shock.

[0006] European Patent No. 3366463 discloses an automotive trim part having a cover layer comprising a carrier layer, a decorative printed thermoplastic film applied to the top of the carrier layer, and a varnish layer applied to the top of the printed thermoplastic film. According to the disclosure of European Patent No. 3366463, the carrier layer preferably consists of a polymer weight layer, with a thin fibrous nonwoven fabric layer applied to its back side. The polymer layer preferably consists of PP or TPO. The decorative printed thermoplastic film can depict images such as nonwoven fabric, felt, wood grain, woven fabric, knitted fabric, or carpet. The top varnish layer, preferably consisting of PU varnish, protects the decorative film from external influences such as impact and abrasion, while the carrier layer provides mechanical resistance and dimensional stability to the trim part.

[0007] While conventional cover layers, such as the one described above, offer an acceptable balance of good appearance, abrasion resistance, cleanability, and mechanical resistance, they may exhibit some drawbacks.

[0008] The visual appearance of this type of cover layer typically relies on a printed layer that exhibits some kind of regular pattern and / or a printed layer that depicts some kind of image (e.g., representing wood grain, woven fabric, etc.). However, the resulting effect is typically perceived by vehicle users as artificial due to the unnatural regularity and / or inherent two-dimensional nature of the printed layer. Furthermore, if the decorative printed layer is worn or damaged during the service life of the vehicle, there is no means to repair the printed decorative layer, so the damage remains clearly visible on the printed decorative surface throughout the entire service life of the vehicle. In addition, the printed patterns and / or images may be distorted during any forming operation required for the manufacture of the cover layer.

[0009] In addition, polymer layers (e.g., TPO layers) typically used in surface cover layers belonging to the prior art may suffer from premature aging and / or seam failure due to severe thermal cycles that the part may undergo during the service life of the vehicle. Furthermore, these same layers also have rather poor elongation behavior and low tensile strength, so during the manufacturing process including forming operations, they may crack or become significantly thinner, which may impair the mechanical properties of the final trim part.

[0010] An object of the present invention is to provide a cover layer for a use surface of an automotive trim part that overcomes the above-mentioned problems of the cover layers belonging to the prior art, as well as a trim part provided with such a cover layer, and a method for producing the same. SUMMARY OF THE INVENTION

[0011] The object of the present invention is achieved by the cover layer according to claim 1, the trim part provided with such a cover layer according to claim 14, and the manufacturing method according to claim 15.

[0012] In a main embodiment of the present invention, the present invention relates to a cover layer for an automotive trim part having a visible side and comprising a porous fiber carrier layer and a thermoplastic polymer matrix, wherein the thermoplastic polymer matrix and the porous fiber carrier layer form a composite layer that forms the visible side of the cover layer, and in the composite layer, the thermoplastic polymer matrix encloses the fibers of the carrier layer and fills the pores between the fibers, and the porous fiber carrier layer is visible from the visible side of the cover layer through the thermoplastic polymer matrix.

[0013] In another embodiment, the present invention relates to an automotive trim part comprising such a cover layer.

[0014] Surprisingly, it has been found that the cover layer according to the present invention may have abrasion resistance, aging degradation characteristics, elongation characteristics, durability characteristics, and washability that are equivalent to or even better than those of cover layers belonging to the prior art. At the same time, the cover layer according to the present invention provides an appearance that is perceived as a natural, genuine woven fabric, essentially given by the random arrangement of fibers in the porous fiber carrier layer, which is visible through the thermoplastic polymer matrix. Furthermore, damage that may occur on the visible side of the cover layer according to the present invention (e.g., scratches) is made less noticeable or not noticeable at all because it is made less noticeable by the random distribution of fibers in the porous fiber carrier layer.

[0015] In this specification, “layer” means an object consisting of one or more materials contained between two adjacent but separated surfaces, where the distance between the surfaces is substantially less than the dimensions of the surfaces. The two surfaces are referred to as the “sides” of the layer, and they are opposite each other. The distance between the two surfaces is referred to as the thickness of the layer, which may be variable.

[0016] A "porous fiber layer" is a layer made up of fibers, in which gaps exist between the fibers, and the dimensions of these gaps are significantly smaller than the length of the fibers. These gaps are referred to as "pores" in this specification.

[0017] The porous fiber "carrier" layer is a porous fiber layer that is self-supporting and provides dimensional stability and mechanical integrity to the cover layer according to the present invention.

[0018] A "composite layer" is a layer made of composite materials. A composite material is a material resulting from a heterogeneous mixture of two or more components (the "components" of the composite material) having different physical and / or chemical properties. A common example of a composite material is concrete, in which loose stones are bound together by a cement matrix. Other common examples of composite materials are carbon-fiber reinforced plastic (CFRP) and glass-fiber reinforced plastic (GFRP).

[0019]

[0020] In the cover layer according to the present invention, the thermoplastic polymer matrix and the porous fiber carrier layer form a composite layer on the visible side of the cover layer, and in the composite layer, the thermoplastic polymer matrix completely encloses the fibers and fills the pores between the fibers.

[0021] In such a cover layer, the thermoplastic polymer matrix provides abrasion resistance and washability while keeping the porous fiber carrier layer visible. At the same time, the porous fiber carrier layer, visible through the thermoplastic polymer matrix, gives the cover layer a natural, authentic woven fabric appearance, while ensuring good dimensional stability and mechanical properties, particularly elongation and tensile strength, due to its fibrous nature.

[0022] To ensure good cleaning properties, in the composite layer according to the present invention, it is essential that the thermoplastic polymer matrix completely encases the fibers of the porous fiber layer, fills the pores between the fibers, and makes the layer completely impermeable to gases and liquids under typical temperature / pressure conditions of passenger cars.

[0023] Therefore, the composite layer according to the present invention achieves a synergistic effect between the thermoplastic polymer matrix and the porous fiber carrier layer, both of which contribute to both the aesthetic appearance of the cover layer and its use-related properties such as abrasion resistance, elongation properties, tear strength, durability, and washability.

[0024] Surprisingly, the cover layer according to the present invention can be realized with a very limited thickness. The thickness of the cover layer according to the present invention is preferably 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 accommodation space occupied by the cover layer according to the present invention is equal to or even smaller than that of cover layers of the prior art.

[0025] The composite layer according to the present invention, formed by a thermoplastic polymer matrix and a porous fiber layer, and forming the visible side of the cover layer according to the present invention, may include the entire porous fiber carrier layer and therefore essentially corresponds to the cover layer according to the present invention. However, the composite layer according to the present invention preferably includes only a portion of the porous fiber carrier layer and therefore accounts for only a portion of the total thickness of the cover layer according to the present invention. In fact, increasing the thickness of the composite layer may improve some performance related to the use of the cover layer according to the present invention, such as abrasion resistance or durability. However, increasing the thickness of the composite layer beyond a certain level comes at the cost of increased difficulty in processing and increased consumption of material used in the thermoplastic polymer matrix, with only slight improvements in performance. In addition, having a certain portion of the porous fiber carrier layer that is not included in the composite layer according to the present invention may improve the sound insulation performance guaranteed by this same cover layer. 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 present invention.

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

[0027] In the composite layer according to the present invention, the side corresponding to the visible side of the cover layer is preferably not smooth in order to prevent the cover layer from having a glossy / shiny appearance, which is generally undesirable in the automotive field. This effect can be achieved, for example, by applying a textured or embossed pattern to the side corresponding to the visible side of the cover layer of the composite layer according to the present invention.

[0028]

[0029] The porous fiber carrier layer may contain any type of natural and / or synthetic fiber common in the industry. Examples of natural fibers include cotton, wool, flax, hemp, bamboo, sisal, jute, coconut, and abaca fibers. Examples of synthetic fibers include polypropylene fibers, polyethylene fibers, polyester fibers, such as terephthalate-based polyester fibers (e.g., polyethylene terephthalate (PET) fibers), polylactic acid (PLA) fibers, and polyamide (PA) fibers, particularly polyamide 6 or polyamide 6.6 fibers. Synthetic fibers may be one-component or two-component fibers. One-component fibers are made from a single material, while two-component fibers are synthetic fibers made from two polymers with different chemical and / or physical structures that are tightly connected to each other along the fiber length. Two-component fibers may be produced using processes known in the art, for example, by melt spinning. The porous fiber layer may consist of only one type of fiber, or it may be a mixture of different types of fibers.

[0030] Advantageously, to reduce the environmental impact of the manufacturing process of the cover layer according to the present invention, particularly its CO2 footprint, the fibers of the porous fiber carrier layer may be at least partially recycled and / or regenerated fibers. In particular, the porous fiber carrier layer may include re-fiber natural fibers, e.g., fibers in the form of re-fiber cotton, and / or re-fiber synthetic fibers, e.g., fibers in the form of re-fiber polyester. Re-fiber type fibers are defined herein as containing at least 51% by weight of recycled fibers of the relevant material. For example, re-fiber cotton contains at least 51% by weight of recycled cotton fibers, and the remaining 49% by weight consists of fibers of different materials and / or virgin fibers.

[0031] Furthermore, the porous fiber carrier layer according to the present invention preferably contains 10% to 50% by weight, and more preferably 20% to 40% by weight, of a binder. The binder may be thermosetting or thermoplastic. In either case, some kind of heat treatment is required to activate the binder. This binder allows the cover layer and / or trim part according to the present invention to be formed into the desired shape during the manufacturing process of the cover layer and / or trim part according to the present invention, while simultaneously firmly bonding the fibers of the porous fiber layer along its entire length. When improved mechanical properties and structural consistency are required, a thermosetting binder may be preferred. On the other hand, when it is necessary to realize a very complex three-dimensional shape, a binder in the form of thermoplastic binder fibers may be preferred, and this may also be advantageous from a sustainability standpoint if the thermoplastic binder fibers and the other fibers of the porous fiber carrier layer belong to the same chemical group, for example, polyester.

[0032] Thermosetting binders are preferably in the form of epoxy resins, phenolic resins, or mixtures thereof. Thermoplastic binders are preferably in the form of thermoplastic binder fibers. These are fibers that contain at least one portion that melts as a result of heat treatment and forms bonds with all other fibers at their intersections / contact points. The melting temperature of the binder fiber (or the melting portion of the binder fiber) (also called the “activation temperature” of the binder fiber) must be significantly lower than the melting temperatures of all other fibers (and any portions of the binder fiber that may not melt). Binder fibers can be one-component or two-component fibers. Particularly preferred as thermoplastic binder fibers are thermoplastic two-component core-sheath binder fibers. Thermoplastic two-component core-sheath binder fibers are two-component fibers in which one of the two components (sheath) surrounds the other (core). The sheath component is the portion of the fiber that melts during heat treatment as described above. In a two-component core sheath binder fiber, the first polymer is preferably polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), and the second polymer is preferably a copolymer of polyethylene terephthalate (coPET) or a copolymer of polybutylene terephthalate (coPBT).

[0033] The fibers contained in the porous fiber carrier layer may have a specific color in order to impart a desired hue or shade to the visible surface of the cover layer according to the present invention.

[0034] The fibers constituting the porous fiber carrier layer can be both short fibers and long fibers (often also called "filaments"). This is also true for thermoplastic binder fibers that may be included in the porous fiber layer according to the present invention. Short fibers, unlike long filaments, are fibers provided in discontinuous predetermined lengths. In particular, the short fibers included in the porous fiber layer preferably have a length of 32 mm to 76 mm.

[0035] 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.

[0036] The formation of the porous fiber carrier layer according to the present invention is preferably carried out by first preparing a fiber nonwoven fabric layer consisting of fibers of a desired fiber composition in the form of a soft mat (hereinafter referred to as a "semi-finished product" or simply a "semi-finished product"), and then molding it under heat.

[0037] The semi-finished product may be prepared according to any method known in the art. Such a method may include, in particular, a first step of forming a fiber web consisting of randomly oriented unbonded fibers of a desired composition, and a second step of partially integrating this same fiber web. In addition to these two steps, the production of the semi-finished product may also include other steps, such as carding and cross-wrapping, which may be considered to give a particular preferred orientation of the fibers forming the web.

[0038] A first process step for forming a fiber web consisting of randomly oriented unbonded fibers of a desired composition can be carried out by techniques known in the art, such as air laying, wet laying, spun laying, melt blowing, and electrospinning. The main objective of this step is to obtain a mixture of randomly oriented unbonded fibers having the desired composition as homogeneous as possible.

[0039] The second process step for partially integrating the aforementioned fiber web may be carried out by bonding techniques known in the art, such as thermal bonding, chemical bonding, mechanical bonding, or a combination thereof. Examples of thermal bonding include hot carrendering and / or infrared heating and / or ultrasonic bonding. Examples of chemical bonding include resin / spray powder bonding and / or foam bonding. Examples of mechanical bonding include needle punching and / or water flow entanglement. The main objective of this partial integration step is to loosely bond the fibers of the fiber web in the semi-finished product to each other so as to give the semi-finished product the integrity necessary for handling the semi-finished product during the manufacturing process of the cover layer or trim part according to the present invention, while maintaining the semi-finished product in the form of a soft mat. Thus, the partial and loose bonding of the fibers in the semi-finished product is significantly different from the complete and strong bonding of the fibers that occurs during the molding of the porous fiber carrier layer under heating.

[0040] The semi-finished product is preferably 100 g / m² 2 ~1600g / m 2 , more preferably 250g / m 2 ~1000g / m 2 More preferably 400g / m² 2 ~650g / m 2 It has a basis weight. 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.

[0041]

[0042] In the cover layer according to the present invention, the porous fiber carrier layer, together with the thermoplastic polymer matrix, forms a composite layer that forms the visible side of the cover layer itself. In the composite layer, the thermoplastic matrix completely encloses the fibers of the porous fiber carrier layer and fills the pores between the fibers.

[0043] In addition, to obtain the desired effect, one or more materials of the thermoplastic polymer matrix must be such that the porous fiber carrier layer is visible through the thermoplastic polymer matrix from the visible side of the cover layer according to the present invention. This can be achieved by using optically transparent or translucent materials. Transparent materials can transmit light without causing significant scattering. When viewed through a transparent material, objects appear sharp, and their shape and boundaries are substantially clearly distinguishable. Translucent materials can also transmit light, but when light passes through a translucent material, associated light scattering phenomena may occur. As a result, when viewed through a translucent material, objects may appear blurred, and their shape and boundaries may be indistinct, but they are still visible.

[0044] To reduce the environmental impact of the manufacturing process of the cover layer according to the present invention, particularly its CO2 footprint, the thermoplastic polymer matrix may, advantageously, include recycled polymer materials.

[0045] The thermoplastic polymer matrix may contain coloring pigments to impart a desired hue or shade to the visible surface of the cover layer according to the present invention. However, even when coloring pigments are added to the thermoplastic polymer matrix, it is essential that the porous fiber carrier layer remains visible through the thermoplastic polymer matrix itself.

[0046] The thermoplastic polymer matrix according to the present invention may include thermoplastic polymers such as polyamide (e.g., polyamide 6 or polyamide 6.6), polypropylene, or polyester (e.g., terephthalate-based polyesters such as polyethylene terephthalate (PET)), or polyester copolymers (e.g., terephthalate-based polyester copolymers such as polyethylene terephthalate copolymer (CoPET)), or polycarbonate (PC). Other examples of thermoplastic polymers that can be used in the polymer layer according to the present invention are polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), polylactic acid (PLA), and polyhydroxyalkanoate (PHA).

[0047] Preferably, the porous fiber carrier layer and the thermoplastic polymer matrix belong to the same chemical group, which can improve the recyclability of both production waste and the complete cover layer and / or trim parts according to the present invention at the end of the vehicle's lifespan. In a preferred embodiment, both the porous fiber carrier layer and the thermoplastic matrix are made of polyester.

[0048] In a particularly preferred embodiment, the porous fiber carrier layer consists of fibers made of PET and / or CoPET, and the thermoplastic polymer matrix consists of CoPET. This embodiment is particularly advantageous in terms of processability and recyclability.

[0049] In another particularly preferred embodiment, the porous fiber carrier consists of fibers composed of PET and / or CoPET, and the thermoplastic polymer matrix consists of polycarbonate. Compared to the case where the thermoplastic polymer matrix consists of CoPET, this embodiment can impart better durability, at the cost of lower recyclability. Furthermore, since polycarbonate and PET / CoPET belong to the polyester chemical family, even the level of recyclability of this embodiment can be considered acceptable in many applications.

[0050] The formation of the composite layer according to the present invention can be obtained according to methods known in the art. In a preferred embodiment, the composite layer according to the present invention is formed by a method comprising at least the following three steps: depositing a thermoplastic polymer material on the surface of the porous fiber layer; heating the thermoplastic polymer material to soften and / or melt the thermoplastic polymer material, causing it to flow around the fibers of the porous fiber layer, penetrate between the fibers, and fill the pores between the fibers; and finally cooling the thermoplastic polymer material to cure the thermoplastic polymer material around the fibers and in the pores between the fibers, thereby forming the composite layer according to the present invention.

[0051] In this preferred embodiment for the formation of the thermoplastic polymer matrix according to the present invention, the amount of the polymer material deposited on the surface of the porous fiber layer is preferably 50g / m 2 ~1000g / m 2 , more preferably 100g / m 2 ~500g / m 2 , even more preferably 150g / m 2 ~300g / m 2 has a basis weight of.

[0052] In this same preferred embodiment, the deposition process may be carried out according to any technique known in the art. For example, it may be carried out by scattering a powdered thermoplastic polymer material onto the surface of the porous fiber layer, or by laminating and / or extruding a layered or film-like thermoplastic polymer material onto the surface of the porous fiber material.

[0053] In a particularly preferred embodiment of this type, the deposition step involves scattering CoPET powder having a particle size of preferably 100 to 800 microns, more preferably 200 to 700 microns, and even more preferably 400 to 600 microns, onto the surface of the porous fiber layer. In this embodiment, the melt flow index (MFI) of CoPET is preferably 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. The 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 their pores. In this embodiment, the melting temperature of CoPET is preferably 120°C to 180°C, more preferably 140°C to 170°C. These temperatures can be easily achieved using standard equipment used in the art.

[0054] In another particularly preferred embodiment of this type, the deposition step involves scattering polycarbonate (PC) powder onto the surface of the porous fiber layer, having a particle size within the same range as specified above for the CoPET powder, but with a melt flow index (MFI) 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. The combination of powder 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 their pores. 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 art.

[0055] The embodiments described herein merely illustrate two examples in which the deposition process involves scattering a powdered thermoplastic polymer material onto the surface of a porous fiber layer. Other materials besides CoPET and polycarbonate may be used. Furthermore, the thermoplastic material may 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 easily adjusted by those skilled in the art.

[0056]

[0057] The cover layer according to the present invention may include other layers in addition to the porous fiber carrier layer and the thermoplastic matrix.

[0058] In one embodiment, the cover layer according to the present invention includes an acoustic barrier layer located on the opposite side of the cover layer from the visible side. The "acoustic barrier layer" is an airtight or air-impermeable layer, that is, a layer that does not allow air to enter or exit, thereby hindering the propagation of sound waves. In the cover layer according to the present invention, the function of the acoustic barrier layer is to improve the sound insulation of the cover layer according to the present invention.

[0059] When particularly lightweight cover layers and / or trim parts are desired according to the present invention, the basis weight of the barrier layer is preferably 10 g / m². 2 ~200g / m 2 Comfortable 50g / m 2 ~150g / m 2 Therefore, the total basis weight of the cover layer according to the present invention is 250 g / m². 2 ~1600g / m 2 More preferably 400g / m² 2 ~1200g / m 2 Furthermore, 600g / m 2 The density is approximately 1000 g / m2. In this case, a preferred embodiment of the barrier layer is a polymeric film 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) and polyethylene (PE); thermoplastic elastomers such as thermoplastic polyolefin (TPO) and thermoplastic polyurethane (TPU) (TPE); elastomers such as EPDM-based elastomers, butadiene-based elastomers, or silicones; high-performance polymers such as polytetrafluoroethylene (PTFE), polyetherimide, polysulfone, polyethersulfone, and polyetheretherketone (PEEK); ethylene vinyl acetate (EVA); and biopolymers such as polylactic acid (PLA).

[0060] Preferably, one or more materials used in the film and one or more materials used in the porous fiber carrier layer and / or thermoplastic polymer matrix belong to the same chemical group to facilitate recycling. The film may be single-layer, double-layer, or multi-layer. Using a double-layer or multi-layer film can further improve stability, elasticity, and / or robustness.

[0061] On the other hand, if a cover layer with particularly improved sound insulation is desired, the basis weight of the barrier layer is preferably 500 g / m². 2 ~8000g / m 2, comfortable 1500g / m 2 ~5000g / m 2 Furthermore, 2000g / m² is more comfortable. 2 ~3500g / m 2 In this case, the total basis weight of the cover layer according to the present invention is 600 g / m². 2 ~10,000 g / m 2 , comfortably 2000g / m 2 ~6000g / m 2 Even more preferable is 2500g / m² 2 ~4000g / m 2 That is the case.

[0062] In this case, a preferred embodiment of the acoustic barrier layer is a layer comprising a matrix of thermoplastic elastomer material with a high concentration of inorganic fillers. Such a layer is commonly referred to in the art as a "heavyweight layer," is airtight, and is therefore suitable for functioning as a barrier layer in the cover layer according to the present invention. In this embodiment of the acoustic barrier 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); polyesters such as polyethylene terephthalate (PET) and / or polybutylene terephthalate (PBT); polypropylene (PP); polyethylenes 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); polyamides 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); and 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.

[0063] In this embodiment of the acoustic barrier layer, the thickness of the barrier layer is always preferably 0.2 mm to 5 mm, more preferably 0.8 mm to 2.5 mm.

[0064] The acoustic barrier layer, particularly its basis weight and material selection, may depend on the desired trade-off between the sound insulation performance and total weight of the cover layer according to the present invention.

[0065] Preferably, in the cover layer according to the present invention, the porous fiber carrier layer and the acoustic barrier layer are adjacent to each other and laminated together. Here, "laminated together" means that the porous fiber carrier layer and the acoustic barrier layer are permanently combined together so that they function together under the action of sound waves striking the sound-reducing trim component according to the present invention. The lamination process may be carried out by means such as heat and / or pressure and / or welding and / or adhesive.

[0066] This lamination process may be easier if the acoustic barrier layer and the porous fiber carrier layer contain materials belonging to the same chemical group.

[0067]

[0068] The trim component according to the present invention may also include other layers, such as a spring layer and / or a sound-absorbing layer and / or a decorative backing layer, in addition to the cover layer according to the present invention. These additional layers are located on the opposite side from the visible side of the cover layer, i.e., between the cover layer and the vehicle body when the component is in use.

[0069] The spring layer is a layer located between the cover layer and the vehicle body when the trim component according to the present invention is used, and has the function of isolating the cover layer from vibrations of the vehicle body, thereby improving the sound insulation characteristics of the trim component according to the present invention. In order to perform this function, the spring layer needs to be positioned so that vibrations from the vehicle body can be effectively transmitted to the spring layer. To achieve this, in some embodiments, the side of the spring layer opposite to the side facing the cover layer may be in contact with the vehicle body at least partially. However, this is not essential for the spring layer to properly perform its function.

[0070] Preferably, the spring layer has a dynamic compressive Young's modulus of 300 kPa or less, more preferably 150 kPa or less, and even more preferably 80 kPa or less. Furthermore, the spring layer may have a variable thickness, preferably 1 mm to 80 mm, more preferably 3 mm to 50 mm, and even more preferably 5 mm to 40 mm. Generally, better performance can be obtained with a lower dynamic compressive Young's modulus and a larger thickness. That is, the spring layer better isolates the cover layer from vehicle body vibrations. However, in practice, the thickness of the spring layer may be limited by design constraints such as housing space or cost.

[0071] The dynamic compressive Young's modulus of a spring layer can be measured using the commercially available Elwis-S instrument sold by Autoneum Management AG. A standard test using the Elwis-S system is performed on a flat, circular sample with a diameter of 100 mm. However, if it is not possible to extract a reasonably flat sample of such diameter from a trim part, the test can be performed on a sample with a smaller diameter. Preferably, the sample diameter should be at least 60 mm. In addition, the load mass used in the Elwis-S test should be such that it ensures the sample under test is properly loaded and uniformly excited across its entire surface. When performing the test using a standard circular sample with a diameter of 100 mm, a load mass of 150 to 400 grams is preferred. To perform the test using circular samples of different diameters, the upper load mass should be rescaled based on the sample surface. Preferably, the dynamic compressive Young's modulus in Elwis-S is obtained by averaging over the optimal frequency range for this measurement system, e.g., 300 Hz to 700 Hz.

[0072] The spring layer may contain any material as long as it performs the main functions described above. Preferably, it contains porous materials and / or cellular materials, which is advantageous in terms of weight reduction.

[0073] In the first embodiment, the spring layer according to the present invention consists of a porous fiber layer. In this embodiment, one or more fiber materials used in the spring layer may be essentially the same as those used in the porous fiber carrier layer according to the present invention. However, in this embodiment, the spring layer is preferably less dense than the porous fiber carrier layer according to the present invention. That is, the spring layer is preferably higher and less compressed, as this helps to enhance the vibration isolation function of the vehicle body. In this embodiment, the density of the spring layer is preferably 30 kg / m³ 3 ~250 kg / m 3 More preferably 40 kg / m 3 ~200kg / m 3, and even more comfortable 50 kg / m 3 ~150kg / m 3 This first embodiment of the spring layer may offer advantages in terms of recyclability after the end of life of the sound-reducing trim component according to the present invention, particularly when one or more materials of the spring layer belong to the same chemical group as one or more materials of the acoustic barrier layer and / or one or more materials of the porous fiber carrier layer and / or one or more materials of the thermoplastic polymer matrix.

[0074] In a second embodiment, the spring layer according to the present invention is made of an open-cell foam, preferably a polyurethane foam. In this embodiment, the density of the foam is preferably 30 kg / m³. 3 ~200kg / m 3 More preferably 40 kg / m 3 ~120 kg / m 3 , and even more comfortable 50 kg / m 3 ~90kg / m 3 This embodiment of the spring layer may be advantageous because the foam, particularly polyurethane foam, provides excellent moldability and greater design flexibility. Therefore, this embodiment may be advantageous when attaching the trim component according to the present invention to a body panel with a complex three-dimensional shape.

[0075]

[0076] The sound-absorbing layer is a layer located between the cover layer and the vehicle body when the component is in use, and has the function of absorbing sound waves radiated from the vehicle body, thereby improving the sound insulation characteristics of the trim component according to the present invention. In order to perform this function, the sound-absorbing layer needs to be positioned such that the side opposite to the side facing the cover layer is at least partially exposed to sound waves radiated from the vehicle body. In some embodiments, this is achieved by providing an air layer between the vehicle body and that side of the sound-absorbing layer.

[0077] The sound-absorbing layer may contain any material as long as it performs the main functions described above. Preferably, it contains porous materials and / or cellular materials, which is advantageous in terms of weight reduction.

[0078] Preferably, the sound-absorbing layer has a sound absorption capacity of 300 Ns / m 3 ~6000Ns / m 3 , more 600 Ns / m 3 ~4000Ns / m 3 Even more convenient: 1000 Ns / m 3 ~2500Ns / m 3 It has an air flow resistance (AFR). The AFR is measured according to ISO 9053-1:2018. Furthermore, the spring layer may have a variable thickness, preferably 1 mm to 80 mm, more preferably 3 mm to 50 mm, and even more preferably 5 mm to 40 mm.

[0079] In the first embodiment, the sound-absorbing layer according to the present invention consists of a porous fiber layer. One or more materials that may 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.

[0080] In a second embodiment, the sound-absorbing layer according to the present invention is made of an open-cell foam. One or more materials that may be used in the sound-absorbing layer according to this second embodiment are the same as those already mentioned for the second embodiment of the spring layer.

[0081] In some embodiments, the sound-absorbing layer may include a thin porous fiber layer (commonly known in the art as "scrim") or microperforated foil having a controlled airflow resistivity (AFR), laminated on the opposite side of the sound-absorbing layer from the side facing the cover layer according to the present invention, in order to improve its sound-absorbing properties. To achieve the desired improvement in the sound-absorbing properties of the sound-absorbing layer, the AFR of the fiber scrim or microperforated polymer foil is preferably at least 50%, and more preferably at least 75%, of the total AFR of the sound-absorbing layer in all areas to which the fiber scrim or microperforated film is applied. The fiber scrim or microperforated polymer foil is preferably 400 g / m² in order not to substantially increase the total weight of the trim part according to the present invention. 2 More preferably 200g / m2 It has the following specifications.

[0082]

[0083] A decorative backing layer is a layer that covers the side of a trim part opposite to the cover layer when the part is in use, i.e., the side that faces the vehicle body when the part is in use. This decorative layer has the function of improving the appearance of the trim part according to the present invention when viewed from this same side. This may be relevant, for example, to removable parts such as a trunk floor cover.

[0084] For the decorative backing layer, any material used in the field for the decorative purposes described above may be used. Examples include fiber scrim, needle-punched carpet, or tufted carpet.

[0085] All of the above preferred embodiments relating to the cover layer, spring layer, sound-absorbing layer, and decorative backing layer can be advantageously combined by those skilled in the art, depending on the desired trade-off between the in-vehicle acoustic effect, weight, process complexity, and design constraints, where it is considered technically possible and appropriate.

[0086]

[0087] The cover layer according to the present invention can be manufactured using apparatus and techniques known in the art.

[0088] A first process for manufacturing a cover layer according to the present invention, suitable for cases where a weight layer is included in the cover layer to improve sound insulation, may include at least the following steps: (a1) A porous fiber layer in the form of a semi-finished product, containing a binder (e.g., a two-component thermoplastic core-sheath binder fiber), is prepared on a horizontal support surface (e.g., a workbench or conveyor belt). Powdered thermoplastic material is sprinkled on top of it. This side will be the visible side of the cover layer according to the present invention at the end of the process. The sprinkling operation can be carried out manually or using an automatic sprinkler as is known in the art. The particle size of the powdered thermoplastic material is preferably about the same as or larger than the typical pore size of the porous fiber layer, so that when the thermoplastic material is scattered on the porous fiber layer, it mainly remains on the surface of the porous fiber layer and does not substantially penetrate into its interior. The powder is preferably spread in an amount sufficient to cover the porous fiber layer as uniformly as possible. For semi-finished layers with a considerably irregular surface, such as those obtained by air lailing, more powder may be needed to ensure good and uniform coverage. For semi-finished layers that have been carded, needle-punched, or calendered, less powder may be sufficient because the surfaces of these porous fiber layers are more regular. (a2) The side of the porous fiber layer on which the thermoplastic powder is scattered is exposed to a heat source, for example, an infrared (Infra-Red, IR) heater. The exposure time and temperature of the heat source must be adjusted so as to soften, or even melt, the powdered thermoplastic material as much as possible, while at the same time avoiding the material substantially beginning to flow into the pores around and between the fibers of the porous fiber layer. This can be achieved by adjusting the exposure time and temperature of the heat source based on parameters such as the amount of thermoplastic material, its softening temperature and melting temperature, and its melt flow index. (a3) A porous fiber layer having a softened thermoplastic material on top is passed through a pair of nip rollers that are cooled or maintained at least at room temperature, with a gap between the rollers being significantly smaller than the thickness of the porous fiber layer (e.g., one-fifth to one-third of the thickness of the porous fiber layer). By passing through the nip rollers (at room temperature, or even lower if cooled), the thermoplastic material hardens and adheres to the porous fiber layer while simultaneously spreading uniformly across the entire surface of the porous fiber layer. As a result of this process, the porous fiber layer is uniformly covered with a thin layer of thermoplastic material having a smooth surface (i.e., much thinner than the porous fiber layer). The thickness of the porous fiber layer does not substantially change during this process. Furthermore, the thin layer of thermoplastic material obtained from this process adheres to and uniformly covers the porous fiber layer, while its penetration into the pores between the fibers is minimized, and it substantially remains on its surface. (a4) Prepare a weight layer and place it on the bottom side of the porous fiber layer, that is, the side opposite to the side covered by the thin layer of thermoplastic material. (a5) A multilayer structure consisting of a thin layer of thermoplastic material, a porous fiber layer, and a heavy layer is placed in a hot press. The gap in the hot press is set to be much smaller than the thickness of the multilayer structure, for example, one-quarter to one-half of the thickness of the multilayer structure. The temperature of the upper plate of the press (i.e., the plate in contact with the thin layer of thermoplastic material) is adjusted to soften the thermoplastic material. At the same time, the temperature of the upper plate of the hot press is set to be higher than the activation temperature of the binder contained in the porous fiber layer. On the other hand, the temperature of the lower plate of the hot press is set to be higher than the softening point of the heavy layer, but lower than its melting point. Next, the multilayer is held in the hot press for a sufficient amount of time to achieve at least the following effects: - Compression in a hot press causes the softened thermoplastic material to flow into the pores around and between the fibers of the porous fiber layer; - Compression in a hot press causes the weight layer to adhere to the porous fiber layer on the opposite side from where the powdered thermoplastic material was initially sprayed; - The binder contained in the porous fiber layer is activated (for example, the sheath of the thermoplastic two-component binder fiber is melted). The time in 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 basis weight / thickness of the porous fiber layer and the type / amount of binder contained therein. (a6) After sufficient time has elapsed to achieve all of the above effects, the multilayer body is removed from the hot press and placed into a cold forming mold comprising a lower mold and an upper mold, wherein when the mold is closed, a mold cavity having the desired three-dimensional shape is defined in the cover layer according to the present invention. Herein, “cold forming mold” means a mold in which the upper mold and lower mold are not actively heated during the molding operation. (a7) The mold is closed and kept closed for a sufficient time for the cover layer to take on and maintain the desired shape due to the curing of the thermoplastic material and the binder contained in the porous fiber layer. In this step, the thermoplastic polymer material cures in the pores around and between the fibers of the porous fiber layer, thereby forming the thermoplastic polymer matrix and composite layer according to the present invention. At the same time, this process imparts its "carrier" function to the porous fiber layer. That is, the presence and compression of the binder gives the porous fiber layer rigidity and self-supporting properties, thereby imparting dimensional stability and mechanical integrity to the cover layer according to the present invention. Furthermore, compression in the mold allows the thermoplastic material to flow further into the pores around and between the fibers of the porous fiber layer, thereby further increasing the thickness of the composite layer according to the present invention. If desired, in this step, the surface of the half-mold facing the visible side of the cover layer may be treated as known in the art to impart a textured or embossed pattern to the visible side of the cover layer according to the present invention. (a8) After the cover layer has taken the desired shape and a sufficient amount of time has elapsed to maintain it, the mold is opened and the cover layer according to the present invention is removed from the mold.

[0089] In a second manufacturing process, which may be particularly suitable when a lightweight cover layer is desired, step (a4) can be omitted, or the weight layer can be replaced with a polymer film in the same step. If this is done, steps (a5) to (a8) must be appropriately adjusted, as is known to those skilled in the art.

[0090] The above-described process for manufacturing a cover layer according to the present invention represents only two examples. Modifications of these processes are possible, for example, that take into account different types of molds and / or further steps to improve the flow of thermoplastic material into the pores of the porous fibrous material, and these can be easily envisioned by those skilled in the art.

[0091]

[0092] Furthermore, a trim part according to the present invention, comprising the cover layer according to the present invention, can also be easily obtained by extending or modifying the above-described process.

[0093] For example, a trim part comprising a cover layer and a spring layer made of open-cell foam according to the present invention can be obtained by acquiring the cover layer according to the present invention obtained in step (a8), and then using a foaming mold to foam the back surface of the cover layer so as to obtain a foam spring layer on the side opposite to the visible side of the cover layer.

[0094] Similarly, trim parts according to the present invention, comprising a sound-absorbing layer and / or a porous fiber spring layer, can be obtained by including such layers in a laminate introduced into a hot press in step (a4), as is known to those skilled in the art, and by appropriately modifying steps (a5) to (a8).

[0095]

[0096] All embodiments described above for the cover layer and / or trim component according to the present invention merely represent possible material arrangements. By considering the characteristics of the materials described herein, in particular their properties, density, thickness and basis weight, those skilled in the art can derive from these embodiments further material arrangements that may be appropriate depending on the situation.

[0097] In addition, further embodiments of the cover layer and trim parts according to the present invention can also be obtained by combining different embodiments and examples of the present invention, and can also be obtained from the description of the embodiments shown in the drawings. The drawings are schematic and not necessarily to scale. All extent disclosed includes endpoints. [Brief explanation of the drawing]

[0098] [Figure 1] Two examples of the cover layer according to the present invention are shown. [Figure 2] Two examples of the cover layer according to the present invention are shown.

[0099] [Figure 3a] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3b] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3c] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3d] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3e] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3f] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3g] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3h] The process for manufacturing the cover layer according to the present invention is shown. [Figure 3i] The process for manufacturing the cover layer according to the present invention is shown.

[0100] Figure 1 shows an example of a cover layer 1 according to the present invention, which comprises a porous fiber carrier layer 2 and a thermoplastic polymer matrix 3, which together form a composite layer 5 including the visible side 4 of the cover layer 1. In this composite layer 5, the thermoplastic polymer matrix 3 encases the fibers and fills the pores between the fibers. Note that the porous fiber carrier 2 includes both fibers included in the composite layer 5 and fibers not included in such a layer, as indicated by the arrows in Figure 1. The porous fiber carrier layer is visible through the thermoplastic polymer matrix. In the example shown in Figure 1, the composite layer 5 does not occupy the total thickness of the cover layer 1. In this example, approximately 50% of the thickness of the porous carrier layer is not included in the composite layer 5.

[0101] Figure 2 shows another example of the cover layer 10 according to the present invention, which further includes a weight layer 6 on the opposite side of the visible side 4.

[0102] The cover layer according to the present invention was manufactured according to the process steps shown in Figures 3a to 3i. The porous fiber layer 20 was prepared on the support conveyor belt 21 (see Figure 3a). The porous fiber layer 20 had a basis weight of approximately 600 g / m². 2 It is a semi-finished product with a thickness of approximately 8 mm and contains the following fiber mixture: 38% by weight of recycled PET fiber, 30% by weight of recycled cotton fiber, and 32% by weight of PET / CoPET core sheath binder fiber with an activation temperature of approximately 120°C.

[0103] As shown in Figure 3a, polycarbonate powder 23 was scattered onto the top of the porous fiber layer using an industrial sprayer 22, so that the powder particles 24 covered the surface of the porous fiber layer 20 as homogeneously and uniformly as possible. The total amount was 200 g / m². 2 Polycarbonate powder 23 was sprinkled onto the top of the porous fiber layer 20. The particle size of the polycarbonate powder was 400 to 600 microns. The melting temperature of the polycarbonate used was approximately 255°C, and the MFI (Metal Fiber Infusion) was 22 g / 10 min at 300°C and 1.2 kg.

[0104] A porous fiber layer with polycarbonate powder sprinkled on top was exposed to an IR heater 25 (see Figure 3c). The temperature of the IR heater 25 was approximately 220°C, and the exposure time was approximately 30 seconds. As a result, the polycarbonate powder particles 24 softened, but the polycarbonate did not begin to flow into the pores around and between the fibers of the porous fiber layer 20.

[0105] Next, as shown in Figure 3c, the porous fiber layer 20, having softened polycarbonate powder 24 on top, was passed between two nip rollers 26 at room temperature. The gap between the nip rollers was approximately 1.8 mm. By passing the layer through the small gap between the nip rollers at room temperature, the polycarbonate layer was uniformly spread across the entire surface of the porous fiber layer and simultaneously cured. As a result of this process, the porous fiber layer was uniformly covered with a thin (i.e., much thinner than the porous fiber layer) polycarbonate layer 27 having a smooth surface.

[0106] Next (see Figure 3d), it is made of EPDM with a high density of inorganic filler, with a thickness of approximately 1.8 mm and a basis weight of approximately 3 kg / m². 2 A weight layer 28 was prepared and placed on the bottom side of the porous fiber layer 20, that is, on the side opposite to the side covered by the polycarbonate thin layer 27. Next, the multilayer body 29, consisting of the polycarbonate thin layer 27, the porous fiber layer 20, and the weight layer 28, was placed in a hot press 30 equipped with an upper plate 31 and a bottom plate 32. The hot press was then closed (see Figure 3e), and the gap was set to approximately 2.5 mm. The temperature of the upper plate 31 was set to 215°C, and the temperature of the bottom plate 32 was set to approximately 70°C. The multilayer body 29 was left in the hot press 30 for approximately 50 seconds. The selected temperature of the upper plate (i.e., the surface in contact with the polycarbonate thin layer) was such that the polycarbonate thin layer 27 would soften. At the same time, the temperature of the upper plate 31 was set to be higher than the activation temperature of the binder contained in the porous fiber layer 20. On the other hand, the temperature of the lower plate 32 of the hot press was set to be higher than the softening point of the weight layer 28, but lower than its melting point. The duration of this compression process within the hot press was empirically adjusted based on a limited number of experiments to achieve the following effects described above: - Softened polycarbonate flows into the pores around and between the fibers of the porous fiber layer; - The weight layer adheres to the porous fiber layer; - The binder contained in the porous fiber layer is activated.

[0107] Next, as shown in Figures 3f and 3g, the hot press 30 was opened and the multilayer body 29 was placed into a cold forming die 33 having an upper mold 34 and a lower mold 35. The cold forming die 33 was closed (see Figure 3h) and kept closed for approximately 45 seconds. After this, the cold forming die 33 was opened (see Figure 3i) and the cover layer 40 according to the present invention was removed from the cold forming die 33.

[0108] Abrasion tests and elongation tests were performed on the cover layer obtained according to the present invention as described in the preceding paragraph. Elongation tests were performed on five specimens taken from the cover layer according to the present invention in accordance with ISO 527-2:2012. The size of the specimens was 170 mm × 25 mm, the clamping distance was 100 mm, and the preload was 5 N. Two quantities were evaluated: Young's modulus and tensile strength in the mechanical direction, which is the most relevant direction in this type of test. As a result, the Young's modulus was shown to be 388 MPa ± 53 MPa, and the tensile strength was shown to be 10.22 MPa ± 0.62 MPa. The values ​​shown here are the average values ​​of the five specimens, and the uncertainty shown is the standard deviation. Abrasion tests were performed on two circular samples with a diameter of 108 mm taken from the cover layer according to the present 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. In these abrasion tests, an H22 wheel was used at a speed of 60 revolutions per minute and under a load of 10 N, with the vacuum cleaner output set to 80%. The wheel was cleaned with a brush after 200, 500, and 800 revolutions. As a result, it was shown that after 1000 revolutions, the weight loss of the first sample was only 0.033 g, and the weight loss of the second sample was only 0.020 g.

[0109] For comparison, we have a TPO layer backed with an EPDM layer, with a basis weight of approximately 3.6 kg / m². 2 Therefore, the same tests were performed on samples taken from the cover layer of a conventional trim part (floor carpet insulator for a B-segment European commercial vehicle) with a basis weight comparable to that of the cover layer according to the present invention. Elongation tests on five specimens showed that in all cases, the Young's modulus was 195 MPa ± 18 MPa and the tensile strength was 3.17 MPa ± 0.12 MPa in the mechanical direction. Both values ​​were significantly lower than those obtained for the cover layer according to the present invention. Abrasion tests on two specimens with initial weights of 32.359 g and 32.269 g, respectively, showed that the weight loss after 1000 rotations was 0.074 grams in both cases, which was significantly higher than the value obtained for the cover layer according to the present invention.

[0110] These results demonstrate that the cover layer according to the present invention provides better elongation and wear characteristics compared to cover layers belonging to the prior art.

Claims

1. A cover layer (1, 10, 40) for an automotive trim part having a visible side (4) and comprising a porous fiber carrier layer (2) and a thermoplastic polymer matrix (3), wherein the thermoplastic polymer matrix (3) and the porous fiber carrier layer (2) form a composite layer (5) that forms the visible side (4) of the cover layer, and in the composite layer (5), the thermoplastic polymer matrix (3) encloses the fibers of the porous fiber carrier layer (2) and fills the pores between the fibers, and the porous fiber carrier layer (2) is visible from the visible side (4) of the cover layer through the thermoplastic polymer matrix (3).

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

3. The cover layer for an automobile trim part according to claim 1 or 2, characterized in that the porous fiber carrier layer comprises at least one of natural fibers, such as cotton fibers, and synthetic fibers, such as polyester fibers, polypropylene fibers, and polyamide fibers.

4. The cover layer according to any one of claims 1 to 3, characterized in that the porous fiber carrier layer includes recycled and / or regenerated fibers.

5. The cover layer according to any one of claims 1 to 4, characterized in that the thermoplastic polymer matrix comprises at least one of polyester, preferably terephthalate-based polyester, more preferably polyethylene terephthalate (PET), a copolymer of terephthalate-based polyester, preferably polyethylene terephthalate copolymer (CoPET), polycarbonate (PC), polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), polylactic acid (PLA), and polyhydroxyalkanoate (PHA).

6. The cover layer according to any one of claims 1 to 5, further comprising an acoustic barrier layer on the opposite side of the visible layer.

7. The formation of the composite layer (5) involves at least the following three steps: - A step of scattering powdered thermoplastic polymer material onto the surface of a porous fiber layer. - A step of softening or melting the thermoplastic polymer material by heat treatment so that the thermoplastic polymer material flows around the fibers of the porous fiber layer, penetrates between the fibers, and fills the pores between the fibers. - The cover layer according to any one of claims 1 to 6, characterized in that it is obtained by a method comprising the step of cooling and curing the thermoplastic polymer material.

8. The cover layer according to claim 7, characterized in that the powdered thermoplastic material comprises a polyester copolymer, preferably a terephthalate-based polyester copolymer, and more preferably a PET copolymer (CoPET).

9. The cover layer according to claim 8, characterized in that the powdered thermoplastic material has a particle size of 100 microns to 800 microns, more preferably 200 microns to 700 microns, and even more preferably 400 microns to 600 microns.

10. The cover layer according to claim 8 or 9, characterized in that the polyester copolymer 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 cover layer according to claim 7, characterized in that the powdered thermoplastic material includes polycarbonate.

12. The cover layer according to claim 11, characterized in that the powdered thermoplastic material has a particle size of 100 microns to 800 microns, more preferably 200 microns to 700 microns, and even more preferably 400 microns to 600 microns.

13. The cover 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 part comprising the cover layer described in claim 1.

15. A method for producing the cover layer described in claim 1, comprising at least the following steps: (a1) Preferably, a porous fiber layer in the form of a semi-finished product is prepared, and a powdered thermoplastic polymer material is scattered on one side of the porous fiber layer. (a2) A step of exposing the side on which the powdered thermoplastic polymer material is scattered to a heat source to soften the thermoplastic polymer material. (a3) A step of passing the porous fiber layer having the softened thermoplastic material on top through a pair of nip rollers, wherein the gap between the nip rollers is smaller 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 side of the porous fiber layer to which the powder was first applied. (a4) A step of placing the multilayer body consisting of the porous fiber layer and the thin thermoplastic polymer layer in a hot press, and closing the press for a sufficient amount of time for the thermoplastic polymer material to soften and flow into the pores around the fibers and between the fibers of the porous fiber layer, (a5) The step of opening the hot press and transferring the multilayer body to a cold forming die having an upper half mold and a lower half mold, (a6). A step of closing the cold forming die and keeping the multilayer body closed for a sufficient time to allow the cover layer to take on the desired shape and to maintain that shape. (a7) A method comprising the step of opening the cold forming die and removing the cover layer from the cold forming die.

Images