Automotive trim parts with vibration damping properties

Abstract

The present invention relates to a noise-damping trim part for an automobile having at least one porous layer, the porous layer having at least one enclosure partially filled with loose particles, the enclosure having a contact surface formed by a membrane for contacting a vibration surface of a vehicle, the surface of the membrane opposite the contact surface being in contact with at least a portion of the loose particles, thereby enabling the membrane to transfer vibration energy from the vibration surface to the loose particles in the enclosure.

Description

[Technical Field]

[0001] The present invention relates to an automotive trim part for noise attenuation in a passenger vehicle, in particular a trim part or cladding that contacts a vibrating surface such as a flooring system, an inner dash, an outer dash, a battery lid insulator, etc., and a vehicle equipped with such a trim part, as well as a method for manufacturing such a trim part. [Background technology]

[0002] Noise sources within a vehicle are manifold and include the powertrain, driveline, tires (excited by the road surface), brakes, and wind, among others. In particular, noise generated by the powertrain and tires can span a relatively large frequency range, ranging from 100 Hz to 10 kHz for conventional diesel and gasoline vehicles, as well as vehicles with electric drive units.

[0003] Low-frequency noise can be considered to cover roughly the frequency range of 100 Hz to 600 Hz. Most low-frequency noise is so-called "structure-borne" noise. In this case, vibrations are transmitted by noise sources (e.g., powertrains or tires) through various structural paths to panels surrounding the passenger compartment, and these panels then radiate the noise into the passenger compartment itself. On the other hand, mid- and high-frequency noise can be considered to cover roughly the frequency range of 600 Hz to 10 kHz. Most mid- and high-frequency noise is "airborne" noise. In this case, vibrations are transmitted by noise sources (e.g., powertrains or tires) through acoustic waves to panels surrounding the passenger compartment, and these panels then radiate the noise into the passenger compartment itself. To ensure passenger comfort, it is necessary to maintain sufficiently low interior noise levels in both the low-frequency and mid- and high-frequency ranges.

[0004] It is known to use noise-damping trim components, such as inner dash systems or floor carpet systems, to attenuate airborne high frequency noise in vehicles.

[0005] Noise-damping trim components generally can effectively reduce mid- to high-frequency airborne noise due to their sound-insulating and / or sound-absorbing properties. Sound-insulating refers to the component's ability to reflect sound energy radiated by a noise source and impinging on the component, while sound-absorbing refers to the component's ability to dissipate sound energy radiated by a noise source and impinging on the component.

[0006] The sound-insulating and sound-absorbing properties of a noise-damping trim part generally result from the materials that make up the part and the material arrangement within the part itself. To achieve particularly good mid- and high-frequency sound-insulating and / or sound-absorbing properties, the part may advantageously include a material layer made of a low-density porous material and arranged on the body-facing side of the part. This layer is arranged in contact with the body when the part is installed in a vehicle. This layer may be made of a low-density fiber material or foam. Additional layers may be required to achieve the desired noise attenuation in the mid- and high-frequency ranges. However, state-of-the-art noise-damping trim parts generally cannot effectively attenuate low-frequency structure-borne noise.

[0007] For this reason, damping pads comprising polymeric viscoelastic materials (e.g., bitumen-based materials) have traditionally been used to attenuate low-frequency structure-borne noise. These damping pads are laminated onto the vehicle body. Due to their damping properties, damping pads are generally very effective in reducing low-frequency structure-borne noise.

[0008] Vibration damping refers to the ability of a part to reduce vibrations in the structure in which it is installed (for example, the body-in-white that forms the body of a vehicle).

[0009] However, viscoelastic damping pads have very low noise damping capacity in the mid-to-high frequency range.

[0010] Therefore, in the state of the art, to achieve good noise attenuation over the entire frequency range, it is generally necessary to combine two different types of components: noise-attenuating trim components for medium and high frequencies and vibration-damping pads for low frequencies.

[0011] As a result, the vehicle assembly process becomes more complex and costly. In particular, the damping pads must be laminated onto the vehicle body, i.e., must be very firmly adhered to the vehicle body, in order to dampen the vibrations of the vehicle body. For this reason, the damping pads are typically first manually positioned on the vehicle body along the vehicle assembly line, and then cured under heat and laminated to the vehicle body. Alternatively, the damping material may be sprayed directly onto the vehicle body in predefined areas. Both of these processes are complex, time-consuming, and require significant capital investment, thereby increasing the complexity of the vehicle assembly process and the vehicle's manufacturing costs, and further delaying the vehicle assembly process. On the other hand, noise-damping trim components can be easily installed on a vehicle by simply attaching them to the vehicle body along the assembly line.

[0012] Furthermore, materials commonly used to manufacture vibration-damping pads can present performance challenges when used in the automotive industry. Damping pads (or spray-on damping materials) used in the automotive field to reduce vehicle body vibrations generally rely on the viscoelastic properties of the materials they contain (e.g., bitumen-based materials), which are highly temperature-sensitive. As a result, damping pads can only function well within a narrow temperature range. However, the temperature of a vehicle body can vary over a very wide range, from -30°C to +80°C. Furthermore, traditional damping materials, such as bitumen-based materials, tend to age, become brittle, and lose their damping performance over the life of the vehicle. Summary of the Invention [Problem to be solved by the invention]

[0013] It is an object of the present invention to eliminate the need for damping pads or spray-on damping materials by providing an alternative noise-damping trim component that can attenuate sound across all required temperature and frequency ranges, meets all acoustic needs for reducing noise inside an automobile passenger compartment, is easily installed in a vehicle, and maintains its performance for the life of the vehicle. [Means for solving the problem]

[0014] The object of the present invention is achieved by a noise-damping trim part for a motor vehicle according to claim 1, by the use of such a trim part according to claim 16, and by a method for manufacturing such a trim part according to claim 15.

[0015] The object of the present invention is achieved in particular by a noise-damping trim part for an automobile comprising at least one porous layer, the porous layer comprising at least one enclosure partially filled with loose particles, the enclosure having a contact surface formed by a membrane for contacting a vibration surface of the vehicle, the surface of the membrane opposite the contact surface being in contact with at least a portion of the loose particles, whereby the membrane is able to transmit vibration energy from the vibration surface to the loose particles in the enclosure.

[0016] Surprisingly, the container with the contact surface formed by the membrane is able to damp vibrations of the vehicle body over an area larger than the actual area of contact, thereby reducing low frequency noise very effectively, while the porous layer and the final additional layer still reduce mid and high frequency noise. For the first time ever, a single trim part is able to attenuate noise over the entire frequency range relevant to acoustic comfort in the passenger compartment of a vehicle.

[0017] The contact surface formed by the membrane is defined as the outer surface of the membrane in contact with the vehicle's vibration panel, and at least a portion of the opposite surface of the membrane is in at least partial contact with the loose particles in the container, so that vibrational energy of the vehicle panel can be transferred to the loose particles in the container, and the movement of the particles dissipates the vibrational energy within the container.

[0018] Preferably, the container is formed by a container portion for maintaining a defined void volume and a closure portion for sealing the container portion after the container portion is filled with particles. The closure portion should be connected to the container portion in such a way that together with the container portion they form a sealed container that prevents leakage of particles during use. Preferably, the closure portion has a contact surface formed by a membrane, and more preferably the closure portion may consist of a membrane.

[0019] Preferably, the enclosed container having a contact surface formed by the membrane is integrated into the porous layer such that the contact surface of the membrane is in contact with the surface of the vehicle that is vibrating, and the surface opposite the contact surface is in contact with at least a portion of the loose particles in the container.

[0020] Preferably, the membrane forming the contact surface is at least flush with the surface of the porous layer. Thus, the porous layer can have at least a portion of its surface in contact with the vibration surface of the vehicle. Preferably, during use, the membrane, at least in the region of the contact surface, can deform slightly, so that when the part is placed on top of a vehicle panel in a vehicle, good contact is achieved even if the vehicle panel surface is uneven or not flat. This can be achieved by selecting the membrane material used.

[0021] Surprisingly, the size of the contact surface of the container(s) is extremely small compared to all surfaces of the trim component that are in contact with vibration surfaces of the vehicle, preferably less than 5% of all surfaces that may be in contact with vibration surfaces of the vehicle, so that the noise absorption and / or sound insulation function of the trim component is still provided and is not substantially affected. Furthermore, a measurable damping effect can be achieved with small containers filled with particles of less than 100 grams each, so that the overall weight of the component is not substantially increased.

[0022] Furthermore, the container's integration into the porous layer allows for accurate and stable placement of the container within the vehicle without requiring additional process steps on the automobile assembly line or additional adhesive or bonding layers. The localized gravity loading of the components on the container also ensures good surface contact between the container's contact surface and the vehicle's vibration surfaces. Meanwhile, the total weight of the components does not affect the container's vibration damping effect.

[0023] Disposed within the porous layer is at least one enclosed container partially filled with the loose particles, preferably comprising a container portion and a closure portion connected together to form an enclosed container having a defined void volume and partially filled with the loose particles.

[0024] The sealed container further comprises a contact surface formed by the membrane for contacting the vibration surface of the vehicle, thereby enabling the sealed container to transfer vibration energy from the vibration surface of the vehicle to the loose particles within the container.

[0025] The enclosed container containing the particles must be positioned within the component so that the particles, under their gravitational load, are at least partially in contact with the surface of the membrane opposite the contact surface. While the component is in use, at least the membrane is in contact with the vibrating surface of the vehicle on one side via the contact surface, and is in contact with at least some of the loose particles in the container on the other side. Thus, when the component is in use, the contact surface can absorb vibrations of the vibrating surface of the vehicle, such as a body-in-white panel or the top of a battery box, and the membrane transmits the vibrations to the opposing part, where they are transmitted to the particles, which are free to move, thereby dissipating this energy through friction and / or inelastic collisions.

[0026] The membrane can be located either in the container part or in the closure part, but is preferably located in the closure part. In another preferred embodiment, the closure part consists of a membrane.

[0027] The particles within the closed container are "loose" in the sense that they are not constrained in any way to remain in a fixed position within the closed container. A closed container that is only partially filled with loose particles according to the present invention allows the particles to move freely within the volume of the container.

[0028] The remaining volume of the container not occupied by the particles can be filled with a fluid that allows the particles to move freely and allows the particles to dissipate energy. Preferably, the remaining volume is filled with air or a suitable gas.

[0029] In particular, when gas or air is used to fill the container, the sealed container must be able to withstand mechanical loads during use, such as pressure from passengers walking on floor parts or pressure from temperature effects that affect the volume of the fill fluid. Therefore, the container part is preferably able to withstand some deformation during use. However, the container must be able to substantially maintain its initial volume and / or shape.

[0030] The membrane must be able to maintain contact with the vibrating surface at all times, at least at the contact surface. Surprisingly, this can be achieved using the membrane without the need for an adhesive layer or any type of mechanical bond. The membrane must also be able to effectively transfer vibrational energy to particles in contact with the membrane within the container.

[0031] Vibrational energy is transferred from the vehicle body to the loose particles in the container via the contact surface formed by the membrane. The efficiency of the vibrational energy transfer can be determined by the material, thickness and mechanical properties of the membrane.

[0032] Additionally, the membrane must be able to withstand the stresses encountered during manufacturing and use and must not fail.

[0033] The thickness of the membrane is preferably 10 μm to 1 mm, preferably 40 μm to 700 μm, and most preferably 60 μm to 300 μm.

[0034] The thickness can vary depending on the material selected for the membrane.

[0035] The properties of the membrane can be altered during the manufacture of the container, for example by stretching it during the lamination process.

[0036] Preferably, the membrane has a tensile modulus of less than 1 GPa, preferably less than 500 MPa, preferably less than 250 MPa. If the membrane is anisotropic, these values refer to both the machine and cross directions.

[0037] The smaller the membrane thickness and / or tensile modulus, the more the membrane will deform and adapt to the shape of the vehicle body, while the thicker the membrane and / or the higher the tensile modulus, the stronger the membrane will be from a mechanical point of view and the easier the manufacturing process will be.

[0038] The membrane preferably has a tensile strength at break greater than 20 MPa and a strain at break greater than 100%. If the membrane is anisotropic, these values refer to both the machine and cross directions.

[0039] Stress and strain at break are measured according to the current versions of ISO 527-1 and 527-3.

[0040] The tensile modulus of a membrane is measured as follows: Several test specimens are prepared according to the instructions given in the current versions of the ISO 527-1 and ISO 527-3 standards. For each specimen, a stress-strain curve is measured according to the current version of ISO 527-1. The tensile modulus of each specimen is evaluated from the corresponding stress-strain curve as the secant modulus between 0% and 2% strain. That is, the following formula holds: E t =(σ2-σ1) / (ε2-ε1) In the formula, E t is the tensile modulus of the specimen, expressed in megapascals (MPa), σ1 is the stress, expressed in MPa, measured at a strain value of ε1 = 0 (0%), and σ2 is the stress, expressed in MPa, measured at a strain value of ε2 = 0.02 (2%). The tensile modulus of the membrane is obtained from the tensile modulus of a single specimen, according to the procedure detailed in the current version of ISO 527-1.

[0041] Preferably, the membrane comprises 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 polyethylene (PE), polypropylene (PP), low density polyethylene (LDPE), linear low density polyethylene (LLDPE) or high density polyethylene (HDPE), or thermoplastic elastomers (TPEs) such as ethylene-acrylic acid copolymer (EAA), thermoplastic polyolefins (TPO), thermoplastic polyurethanes (TPU), polyetherimides, polysulfones, polyethersulfones, polyetheretherketone (PEEK), ethylene vinyl acetate (EVA), or biopolymers such as polylactic acid or ionomeric polymers.

[0042] Preferably, a thermoplastic material is used, preferably a polyester or polyolefin. Preferably, the material of the membrane, the container part and / or the entire container is from the same group of materials as the porous layer, making it easy to recycle.

[0043] Additionally, bilayer or multilayer membranes can be used to further improve stability, resilience, and / or robustness.

[0044] The membrane can be laminated directly to the rim of the container part to seal the container after the loose particles have been filled in. In particular, when the membrane is laminated directly to the container part, a bi-layer or multi-layer membrane is preferred, where one layer is selected for good sealing of the container part, while the other layer or layers are responsible for good lamination and can fuse with the rim of the container part or fuse against the rim of the container to form a hermetic seal.

[0045] Alternatively, a glue or adhesive layer can be used to connect the container part and the closure part to provide a sealed container.

[0046] Preferably, the portion of the membrane that contacts the vehicle body when the part is in use is not attached (eg, glued) to the vehicle body itself.

[0047] Surprisingly, when the membrane according to the present invention is used to transmit vibrations of the vehicle body to loose particles in a container, it is not necessary to glue the membrane to the vehicle body in order to efficiently transfer the vibration energy to the particles. Due to the high flexibility of the membrane, the damping effect is the same or at least not significantly different compared to the damping effect obtained when the membrane is attached, e.g., glued, to the vehicle body during use. Gluing the membrane to the vehicle body when placing the trim part on a vehicle would make the installation process of the trim part longer and less robust; therefore, having a solution that does not require glueing is extremely convenient, facilitating the installation process and reducing the time and cost of assembling the vehicle.

[0048] Alternatively, a bonding solution may be used that uses a non-permanent adhesive, or a pressure sensitive adhesive solution that provides a strong bond between the contact surface and the vehicle body during use, the latter of which may be advantageous for vehicle ramps.

[0049] The particles used are extremely small, with a minimum size of at least 20 μm, and these particles can get into the seams of the laminate or into tiny flaws in the membrane layer, leaking out of the container and impairing its function over time. To prevent particles from leaking out of the container, the material of the container, including the membrane, must be impermeable. Here, "impermeable" means that particles cannot pass through an intact membrane. Preferably, at least a bilayer or multilayer membrane is used as the membrane.

[0050] Disjointed particles In the noise-damping trim part according to the present invention, vibration damping effect in the low frequency range, i.e., 100 Hz to 600 Hz, is achieved due to the fact that the vibration energy of the vehicle body is transmitted to the loose particles in the container, which dissipate the vibration energy by friction and / or inelastic collisions.

[0051] The frequency range in which the loose particles in the container are most effective at dissipating vibrational energy through friction and inelastic collisions can be adjusted by appropriately selecting the statistical distribution of the loose particle sizes.

[0052] "Particle size" when referring to an individual particle is defined as the area equivalent to its circular diameter measured according to the current ISO 13322-2 standard.

[0053] Particles within a single container may have different particle sizes. From the particle sizes of the individual particles measured according to the current version of ISO 13322-2, the statistical distribution of particle sizes within the container can be estimated, for example, according to the instructions of the current version of ISO 9672-2.

[0054] In the following description, the term "particle size" when referring to a population of particles in a container refers to the median value D of the statistical distribution of particle sizes in the container. 50 shall be understood to refer to

[0055] Furthermore, the term "particle size distribution span" or "distribution span" when referring to a population of particles in a container is defined by the formula S=(D 90 -D 10 ) / D 50 where D 10 is the particle size at 10% of the cumulative value, and D 90 is the particle size at 90% of the cumulative value, and both are calculated from the statistical particle size distribution. The particle size distribution span is the distance from the median value D 50 It is a measure of how dispersed the particles are in the vicinity.

[0056] Preferably, the particles in the container have a median particle size of 20 μm to 1250 μm, preferably 250 μm to 1000 μm, preferably 350 μm to 700 μm.

[0057] Preferably, the particles in the container have a particle size distribution span of 2.5 or less, preferably 1.5 or less, preferably 1 or less.

[0058] Larger particles are more effective at dissipating energy through friction and inelastic collisions at lower frequencies, i.e., around 100 Hz, and less effective at higher frequencies, i.e., around 600 Hz, so that the total frequencies attenuated are in the range of 100 Hz to 600 Hz.

[0059] On the other hand, smaller particle sizes are more effective at dissipating energy through friction and inelastic collisions at higher frequencies, i.e., around 600 Hz, and less effective at lower frequencies, i.e., around 100 Hz, so that the total frequencies attenuated are in the range of 100 Hz to 600 Hz. Furthermore, energy dissipation is broader for particles with smaller particle sizes than for particles with larger particle sizes.

[0060] By selecting the median value and span of the particle size distribution within the container, it is possible to adjust the location and width of the frequency range in which the particles are most effective at dissipating energy through friction and inelastic collisions, which is the frequency range in which the container of the present invention is most effective at damping vehicle body vibrations.

[0061] If a high damping effect at a lower frequency is desired, a larger median particle size, for example, a median particle size greater than 350 μm, should be selected, whereas if a high damping effect at a higher frequency is desired, a smaller median particle size, for example, a median particle size less than 350 μm, should be selected.

[0062] The distribution span should be selected based on the width of the frequency range over which the damping effect is desired: increasing the span for a given amount of particles will result in a broader band, but less pronounced effect.

[0063] A trim part may comprise more than one container. By using different particle size distributions in different containers, it may be possible to optimize the overall damping performance of the part.

[0064] In a vehicle panel, such as a floor panel, the frequency content of vibrations in different regions may differ. Some regions may vibrate primarily at lower frequencies, e.g., below 250 Hz, and some other regions may vibrate primarily at higher frequencies, e.g., above 250 Hz. In some regions, the vibrations may be broader, while in some other regions, the vibrations may be more concentrated in a limited frequency range.

[0065] Surprisingly, by selecting the particle size distribution of the particles contained in the containers, the trim component of the present invention can be configured to effectively damp vibrations in various regions of the vehicle body panel, even if the frequency content differs. This is possible by selecting the median and span of the particle size distribution of the particles in each container to match the frequency content of the vehicle body vibrations in the region where the container is located.

[0066] To damp vibrations in areas that vibrate primarily at low frequencies, a particle size distribution with a larger median value, for example, greater than 350 μm, is selected. For areas that vibrate primarily at higher frequencies, a particle size distribution with a smaller median value, for example, less than 350 μm, should be selected. Similarly, for areas with broader vibrations, a larger span particle size distribution can be selected, and for areas with less broadband vibrations, a smaller span particle size distribution can be selected. This is an advantage over conventional damping pads, which cannot be adjusted for different areas of a body panel.

[0067] Preferably, the total weight of the particles in one container is 5 to 100 grams, preferably 8 to 60 grams, preferably 10 to 50 grams.

[0068] Surprisingly, this low weight can be used to effectively reduce low frequency structure borne vibrations of the vehicle body.

[0069] The "filling factor" of a container represents the ratio of the volume occupied by the particles contained in the container to the total internal volume of the container.

[0070] The frequency range in which the loose particles within the container are most effective at dissipating vibration energy through friction and inelastic collisions can be fine-tuned by selecting the fill factor: lower fill factors increase performance at lower frequencies, i.e., near 100 Hz, while higher fill factors increase performance at higher frequencies, i.e., near 600 Hz, so that all frequencies attenuated are in the 100 Hz to 600 Hz range.

[0071] The containers included in the noise-damping trim components of the present invention preferably have a fill factor of 30% to 90%, more preferably 40% to 70%. Fill factors greater than 90% are not preferred because they leave too little space for particles to move freely within the container.

[0072] The particles are loose granular materials, preferably made of at least one material selected from the group consisting of inert minerals such as calcium carbonate or silicon dioxide, metals such as steel, ceramic materials, elastomeric materials, and polymeric materials such as polystyrene. Particles made of different materials may be used in a single container.

[0073] Surprisingly, compounds made of particles made of elastomeric materials from synthetic sources or natural rubber, such as styrene-butadiene rubber, nitrile rubber, rubber from ethylene propylene diene monomer (EPDM) and butyl rubber, or combinations thereof, can also achieve good damping results. The compounds can be crosslinked by typical means, such as vulcanization or radical crosslinking, or can be non-crosslinked.

[0074] The materials used may be virgin or from recycled or reclaimed sources. For example, granulated particles from recycled tires are a good filler material for the loose particles of the present invention. When using elastomeric materials, a medium particle size, for example, between 200 μm and 800 μm, may be used.

[0075] The final choice of material for the discrete particles depends on the frequency range to be attenuated and the corresponding particle size distribution desired, as well as price and availability.

[0076] The performance of the trim part of the present invention can be optimized and fine-tuned by appropriately selecting the particle size distribution of the loose particles in the container, the material of said particles, the total weight and relative loading, and taking advantage of the interrelationships that exist between all these parameters. A given material is such that the damping performance of the part is not substantially affected by temperature changes during use in a vehicle, contrary to state-of-the-art damping pads. This is a major advantage, as it eliminates the need to adapt material properties to local markets depending on the outdoor temperature in the market.

[0077] The container includes a container portion and a lid portion (closure portion). The container portion defines an interior volume that is maintained during manufacture and use of the trim part. The defined interior volume of the container must be large enough to contain the particles but also large enough to allow the particles to move freely within the container when subjected to vibration.

[0078] Preferably, the container included in the noise-damping trim part according to the present invention has an internal volume of 2 cm 3 ~100cm 3 , preferably 5 cm 3 ~50cm 3 , preferably 10 cm 3 ~30cm 3 and particle packing is less than 90% of the total internal volume.

[0079] The container is preferably much stiffer than the membrane to ensure dimensional stability and structural robustness to the container.

[0080] Preferably, the container is made of a thermoplastic material having a Young's modulus of 0.7 GPa to 4 GPa, preferably 1.0 GPa to 3 GPa.

[0081] Preferably, the wall of the container has a thickness of 1.5 mm to 5 mm, preferably 2.5 mm to 4 mm.

[0082] The actual thickness of the container wall may depend on the manufacturing process of the container, for example, injection molding, blow molding, thermoforming, or additive manufacturing techniques such as 3D printing, and this thickness may vary across the container wall, for example, by blow molding or thermoforming, and thin and thick regions may exist within the container wall.

[0083] Preferably, the container part comprises 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 polyethylene (PE), polypropylene (PP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or high-density polyethylene (HDPE), ionomers such as ethylene-acrylic acid copolymer (EAA), thermoplastic elastomers (TPE) such as thermoplastic polyolefin (TPO), thermoplastic polyurethane (TPU), polycarbonate (PC), polyimides such as polyetherimide (PEI) or polyetheretherketone (PEEK), polysulfone, polyethersulfone, ethylene vinyl acetate (EVA), or biopolymers such as polylactic acid (PLA). Combinations of these materials may also be used.

[0084] Preferably, the container portion is comprised of at least one layer comprising one of the listed materials, although multi-layer materials may also be used to make the container portion according to the present invention.

[0085] Preferably, the container portion further comprises reinforcing fibers, for example glass fibers or polycarbonate fibers, to further improve the rigidity and robustness of the container portion.

[0086] The shape of the container part can be adapted to allow easy insertion into the porous layer, while also being designed to include means for maintaining the container on the trim part during transportation or handling of the trim part, for example, during installation of the trim part in a vehicle. For example, these means can be achieved by adapting the basic shape of the container part. For example, a shape with a slightly smaller cross-section at the contact surface and expanding towards the bottom of the container can prevent the container from falling out during handling, with slightly tapered or curved sides being preferred. Additionally, other means, such as ribs, small embossments or screw-type grooves may secure the container part in place.

[0087] Alternatively, or in combination with an optimized shape, the container and / or lid may form a flange that prevents the container from sinking too far into the porous layer. In order for the container according to the invention to dissipate vibration energy, it must be ensured that the contact surface can contact and maintain contact with the vibrating surface of the vehicle. Therefore, the container must not sink into the porous layer, and the contact surface must be at least substantially flush with the surface of the porous layer, including the contact surface. Small local deviations in the surface can be overcome by local deformation of the contact surface formed by the membrane, which deformation can take place both inward and outward relative to the plane of the surface.

[0088] For this purpose, the container part may be fitted with a flange, which preferably contacts the surface of the porous layer adjacent to the container part and avoids the above-mentioned sinking. In addition, the flange area can further increase the contact surface between the lid part and the container part, creating a larger area for lamination and sealing, which is very convenient for easier manufacturing of the container.

[0089] For example, the container may be shaped like a parallelepiped or a cylinder. In another embodiment, the container may be shaped like a hemisphere, where the flat side of the hemisphere comprises a closure with a membrane. A hemisphere has the advantage that any pressure on the container from above the hemisphere is evenly distributed, preventing the container from cracking or bursting during use.

[0090] Parallelepiped, hemispherical and / or cylindrical shapes are very simple shapes that can be easily manufactured and allow for easy incorporation of the container into the trim part.

[0091] In another embodiment, the container is shaped like an inverted truncated cone (a cone with the top cut off and turned upside down), with a smaller base consisting of a membrane closure. In this embodiment, if the container is embedded in the trim part, the shape can help prevent the container from falling out of the trim part itself. This makes the part easier, faster, and therefore cheaper to manufacture.

[0092] This effect can also be achieved with other container shapes, such as an inverted truncated pyramid or barrel shape, or other shapes, as will be apparent to those skilled in the art.

[0093] Preferably, the container portion has an edge to which the membrane can be attached, for example by gluing or thermal bonding. Preferably, the edge of the container portion is fitted with a protruding flange having a width of at least 1 mm. The flange can increase the bonding surface for the membrane. The flange also helps prevent the container from sinking into the porous layer when the container is embedded in the porous layer.

[0094] Preferably, the height of the container is at least 5 mm less than the thickness of the porous layer to ensure that there is at least 5 mm of porous material above the container. Quite surprisingly, when this condition is met, the presence of the container does not substantially affect the high frequency airborne noise performance of the trim component.

[0095] Preferably, the Noise damping trim part according to the invention comprises several containers, the number of which is defined based on the desired damping performance and on weight, space and cost constraints, with an increased number of containers resulting in higher performance but also increasing weight, cost and complexity of the manufacturing process.

[0096] Preferably, the porous layer of the noise-damping trim part according to the invention may contain up to 30 reservoirs, preferably 4 to 30 reservoirs, more preferably 8 to 20 reservoirs.

[0097] Surprisingly, the containers each have a fill weight of 100 grams or less and therefore require much less weight overall to achieve satisfactory damping compared to state-of-the-art dampers used to damp the same surface, thereby reducing the weight of the vehicle and therefore the vehicle's energy consumption.

[0098] By integrating the container into the trim part, the location of the container can be predefined, and the correct positioning of the container is guaranteed during installation of the trim part. Preferably, the container is located in the location where vibrations on the vehicle body are most pronounced, the so-called "vibration hotspots". Such vibration hotspots can be identified using experimental and / or simulation techniques well known in the art. There may be several vibration hotspots on a vehicle body panel, and these vibration hotspots may relate to different frequency ranges. Therefore, it may be preferable to use containers partially filled with different types of loose particles within the same part.

[0099] The noise-damping trim component of the present invention is preferably installed on a primarily horizontal body panel (e.g., a vehicle floor), but can also function when installed on a body panel with a different orientation (e.g., a vehicle dash panel), provided that when the component is installed on the vehicle, under the gravitational load of the particles, loose particles within the container are in at least partial contact with the membrane in the area where the membrane contacts the vibration surface of the vehicle body.

[0100] The containers embedded in the noise-damping trim components of the present invention may all have the same characteristics with respect to size, shape, particle type, and packing density, or they may have different characteristics so as to conform to the shape of the body and / or trim component when installed in the vehicle, as well as the vibration of the body panel with which the component is in contact.

[0101] In the trim component according to the present invention, the container partially filled with loose particles is embedded in a porous layer, preferably made of an open-cell foam material and / or a fibrous material.

[0102] The porous layer may be formed from any type of open-cell foam, preferably the porous layer is made of polyurethane foam. Preferably the foam has a density of 25 kg / m 3 ~120kg / m 3 , preferably 35 kg / m 3 ~80kg / m 3 , preferably 45 kg / m 3 ~70kg / m 3 It has a density of

[0103] The porous layer may be a fibrous layer comprising fibers, such as staple fibers, and / or filaments, and a thermoplastic binder material.

[0104] Any combination of recycled, reclaimed, or virgin, man-made, inorganic, and / or natural fibers can be used.

[0105] For example, the porous layer may include recycled fibers made of at least one material selected from the group consisting of recycled cotton fibers, recycled synthetic fibers, recycled polyester fibers, recycled natural fibers, and recycled synthetic and natural fiber blends.

[0106] A type of recycled fiber is defined by containing at least 51% by weight of the referenced material, with 49% possibly being fibers from other sources. Thus, for example, recycled polyester fiber contains at least 51% by weight of polyester-based fibers. Alternatively, recycled fiber materials may be a mixture of different synthetic and natural fibers, so that no one type predominates.

[0107] Preferably, the fibers or filaments are made of at least one material selected from the group consisting of polyamides (nylons), such as polyamide 6 or polyamide 66; polyesters, such as polyester terephthalate (PET) or copolymers of polybutylene terephthalate (PBT) or polytrimethylene terephthalate (PTT); polyolefins, such as polypropylene; or polyethylenes, such as copolymers of polyethylene; and mineral fibers, preferably one of glass fibers or recycled glass fibers or basalt fibers or carbon fibers.

[0108] Preferably, the porous layer comprises self-crimping fibers, preferably hollow self-crimping fibers.

[0109] The porous layer may comprise a thermosetting binder, for example a binder based on a phenolic resin or an epoxy resin, or a thermoplastic binder made of at least one material selected from the group consisting of polyesters such as polyethylene terephthalate (PET), polyester copolymers, polyolefins such as polypropylene or polyethylene, polylactic acid (PLA), and polyamides such as polyamide 6 or polyamide 66.

[0110] Preferably, the binder material is in the form of fibers, flakes or powder. More preferably, the binder material is either a monocomponent fiber or a bicomponent fiber.

[0111] The thickness of the porous layer with the container partially filled with loose particles is generally not constant and is determined mainly by the space constraints within the vehicle. The available thickness can vary between 2 mm and 100 mm, but in most cases the thickness is between 5 mm and 40 mm. The typical average thickness of a porous layer as part of a carpet or inner dash is usually between 10 and 30 mm, for example, on average about 20 mm.

[0112] Preferably, the area weight of the porous layer in which the container is embedded is 400 g / m 2 ~2000g / m 2 , preferably 800 g / m 2 ~1600g / m 2 is.

[0113] The automotive noise-damping trim component of the present invention may include one or more additional layers on the surface opposite the surface intended to contact the vehicle's diaphragm panel. The additional layer may be at least one other porous layer, preferably a selected foam or felt containing the materials defined above. Additionally or alternatively, the additional layer may be a membrane, a layer of a high-density material known in the industry as a heavy layer material, a thermoplastic elastomer material with a high filler content, a decorative layer such as a nonwoven layer or carpet layer, or any combination of such layers.

[0114] Alternatively, a scrim layer may be placed on the side of the porous layer that contacts the vibrating vehicle panel. The thickness of such a nonwoven or scrim layer should not introduce a height such that the contact surface of the container no longer contacts the vibrating surface of the vehicle.

[0115] In one preferred embodiment, the trim component of the present invention is a spring-mass system formed from a low density soft decoupling layer and a high density encapsulating weight layer, where the partially filled container with loose particles is contained in the porous layer that is the decoupler, and the decoupler is positioned to contact the vibrating body panel when the component is installed in a vehicle. Preferably, the mass or weight layer has a density of 500 g / m 2~6500g / m 2 The trim component has an areal weight of 1000 lbs. Finally, the trim component may include additional layers on top of the surface of the heavy layer, such as a reinforcing layer and / or a carpet layer, e.g., a nonwoven or tufted carpet. Such components may be molded to form, for example, inner dash trim components, outer dash trim components, and / or flooring sections for the passenger compartment of an automobile, or may be used in the front or rear trunk areas.

[0116] Preferably, the heavy layer comprises a thermosetting plastic material selected from the group consisting of ethylene vinyl acetate (EVA) copolymer, polyester, polyethylene terephthalate, high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, thermoplastic elastomer, thermoplastic rubber, polyvinyl chloride (PVC), or any combination thereof. Additionally, the heavy layer may comprise up to 85% by weight of an inorganic filler to increase the density of the material.

[0117] In this embodiment, the trim component of the present invention may comprise additional layers on top of the mass layer, such as a covering scrim layer, an acoustic scrim layer, a decorative top layer, for example, a tufted or nonwoven carpet layer.

[0118] In this case, by providing an additional porous layer on top of the heavy layer, the trim part can attenuate noise based on at least sound insulation and damping, while also providing noise attenuation based on noise absorption.

[0119] Another preferred embodiment is a trim part comprising a fibrous porous layer provided with a container according to the invention, which has a higher airflow resistance than the layer provided with the container, preferably 500 Ns·m -3 ~4000Ns·m -3 The trim part further comprises at least one additional fibrous porous layer having an airflow resistance of 100 MPa or more on top of the porous layer having the container, thereby achieving enhanced noise absorption in addition to the damping properties.

[0120] Another preferred embodiment is a trim component comprising an open-cell foam layer with a container according to the present invention, the trim component having a resistance of 500 Ns·m -3 ~4000Ns·m -3 and an intermediate membrane or scrim layer between the two porous layers. In this embodiment, the open-cell foam layer containing the container of the present invention contacts the vehicle body when the part is installed in the vehicle, while the porous fibrous layer faces the passenger compartment. The presence of the intermediate membrane or scrim helps to improve the sound insulation properties of the trim part at mid- to high-frequency levels, while the top porous layer ensures good absorption properties at mid- to high-frequency levels.

[0121] Any of these embodiments can be used to achieve good noise attenuation and sound insulation and / or absorption attenuation covering the frequency range from 100 Hz to 10 kHz.

[0122] Trim components according to the present invention can be manufactured according to methods well known in the art.

[0123] By way of example, the manufacture of a trim component according to the present invention can be carried out according to the steps set out below.

[0124] In a first step, the container part is manufactured from a thermoplastic polymer material, such as, for example, polypropylene, or any other material as defined above, using techniques well known in the art, such as injection molding, blow molding, vacuum forming, or by additive manufacturing (additive manufacturing) or 3D printing.

[0125] Preferably the container is shaped as, for example, a recessed container bounded by a rim, and has a small flange around the rim, preferably having a width of at least 1 mm.

[0126] The container walls must at least be hermetically sealed so that the particles used cannot escape through small gaps in the walls. If the process for forming the container portion produces multiple porous walls, such as additive manufacturing, one or more container surfaces can be treated, for example with a coating, to achieve the required hermetic structure.

[0127] In a second step, a desired amount of the loose particles is placed into the container prepared in the first step.

[0128] In a third step, a membrane is laminated onto the container containing the loose particles and joined to its edges so that, together with the remainder of the container wall, it defines an enclosed volume containing the particles.

[0129] The joining process can be carried out using techniques known in the art, such as, for example, adhesive or thermal bonding. The presence of a small flange around the edge of the remaining portion of the container wall produced in the first step can facilitate the joining process. However, joining is possible without this flange. Optionally, before or after joining, the rim and membrane can be folded together to strengthen the joining zone and prevent particle leakage during use.

[0130] Alternatively, a heat wrap foil may be used which can cover the container and wrap at least partially around the walls of the container, after heat treatment the foil bonds to the rim and walls of the container part forming a sealed container.

[0131] The container portion and the container can be manufactured in different steps and processes, which may be separated geographically and / or temporally.

[0132] In another process, a trim part is manufactured with a porous layer having a portion of its exterior surface that faces the body when the part is installed in a vehicle, and this portion of the exterior surface of the part has a recess that is shaped to match the shape of the loose particle-filled container manufactured in the process described above.

[0133] The trim piece may have the recesses already formed when the trim piece is molded, or the recesses may be cut in a separate step before or after molding.

[0134] In an alternative process, the container is placed in a mold and the trim piece is manufactured to directly encase the container using, for example, an in-mold foam process or an injected fiber process.

[0135] The trim parts produced in this fourth step may have complex three-dimensional shapes, thereby fitting into the space available within the passenger compartment.

[0136] This process can be carried out using standard manufacturing methods known in the art. For example, a heavy barrier layer can be first shaped by vacuum forming and subsequent defoaming, where a defoaming tool provides protrusions that conform to the shape of the container. Additional layers, such as porous felt or foam layers, or needle-punched or tufted carpet, can then be added on top of the heavy layer.

[0137] Finally, in an additional step, the container is embedded in the porous layer by inserting it into a recess in the porous layer.

[0138] Insertion of the container into the recess is preferably performed in an automated manner, but may also be performed manually.

[0139] The presence of a flange around the edge of the container facilitates the insertion process as it helps to prevent the container from sinking into the porous layer, however, proper and accurate integration of the container into the trim part is possible without the flange.

[0140] Preferably, the container is adhered on at least a portion of its outer surface to the porous layer in which it is embedded, which helps to prevent the container from becoming detached from the trim piece during the manufacturing process or during installation of the trim piece on the vehicle.

[0141] However, bonding of the container to the trim part is not necessary to prevent the container from falling off from the trim part: this effect can also be achieved in other ways, for example by shaping the container in a suitable way (e.g., barrel-shaped containers, inverted truncated pyramid-shaped containers) or by providing the container with some mechanical fixing elements (e.g., thin-walled external protrusions in the form of spines or hooks), or by a combination of at least partial bonding and a suitable shape.

[0142] Preferably, the trim part of the present invention is a noise-damping trim part for a battery cover or housing, inner dash, outer dash, or carpet system, such as tufted carpet, needle-punched carpet, carpet with a flocked surface, or Dilour carpet, in which, when the part is installed in a vehicle, a porous layer burying a container partially filled with loose particles faces a vibrating body panel.

[0143] Any ranges given throughout this specification must include the starting and ending points of the measurements and normal expected deviations. Ranges may also combine different starting and ending values.

[0144] Further embodiments of the invention can be derived from the description herein, and can also be derived by combining different embodiments and examples of the invention, and may also be derived from the description of the embodiments shown in the drawings, which are schematic and not necessarily to scale. [Brief explanation of the drawings]

[0145] [Figure 1] FIG. 1 is a schematic cross-sectional view of a trim component according to the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view of a trim piece according to the present invention before embedding a container in a porous layer. [Figure 3]FIG. 3 is a schematic cross-sectional view of a component according to the invention when installed on a predominantly horizontal panel of a vehicle. [Figure 4] FIG. 4 is a schematic cross-sectional view of a component according to the invention when installed on a primarily vertical panel of a vehicle. [Figure 5a] FIG. 5a is a schematic cross-sectional view of a container partially filled with loose particles according to the present invention. [Figure 5b] FIG. 5b is a schematic cross-sectional view of a container partially filled with loose particles according to the present invention. [Figure 5c] FIG. 5c is a schematic cross-sectional view of a container partially filled with loose particles according to the present invention. [Figure 6] FIG. 6 is a diagram showing an example of a 3D molded part according to the present invention. [Figure 7] FIG. 7 is a schematic top view of the vehicle floor. [Figure 8] FIG. 8 is a diagram showing vibration levels of the vehicle body. DETAILED DESCRIPTION OF THE INVENTION

[0146] FIG. 1 is a schematic cross-sectional view of an example of a trim part (11) according to the present invention. The part includes a porous layer (7), a mass layer (8), and a carpet layer (9). The porous layer has a portion of its outer surface (10) for contacting a vibrating vehicle surface when the part is installed in a vehicle. The part further includes a sealed container (1) partially filled with loose particles (3). The interior volume (2) of the container not occupied by the loose particles is filled with air. In this example, the wall of the container includes a contact surface (4) made of a membrane, and the remaining wall of the container (5) is shaped like the container, being much thicker and more rigid than the membrane. The contact surface (4) and the container (5) are connected along their edges, whereby the contact surface (4) serves as a closure for the container (5) and together they form the sealed container ( 1) The container is integrated into the porous layer (7) so that the membrane closure (4) is flush with the portion (10) of the porous layer intended to contact the vibrating vehicle surface when the part is installed in the vehicle. The loose particles (3) are in contact with the membrane closure (4), and under the load of the particles' weight, the thin, flexible membrane (4) deforms and "bulges" outward. As a result of this deformation, the contact surface (4) conforms to the shape of the vibrating vehicle surface itself when the part is installed in the vehicle.

[0147] The deformation of the membrane depends on the membrane's mechanical and physical properties and its dimensions. The smaller the membrane's Young's modulus and / or its thickness, the greater the deformation. For example, a membrane with a Young's modulus of 250 MPa, a thickness of 27 μm, and dimensions of 50 mm x 50 mm will have a maximum "outward bulge" of about 2 mm. This is sufficient to compensate for most of the irregularities found in a body panel.

[0148] FIG. 2 is a schematic cross-sectional view of the same noise-damping component according to the present invention, before the container (1) is embedded in the porous layer (7). The porous layer (7) preferably has a recess (16) whose shape matches the shape of the container (1). The container (1) can be embedded in the porous layer (7) by inserting it into the recess (16). This operation is preferably performed in an automated manner using a suitable mechanical tool known in the art, but may also be performed manually. Preferably, a quantity of adhesive (18) is distributed over at least a portion of the surface of the container (1) to facilitate adhesion to the surface of the porous layer and to prevent the container from falling off during handling operations required for installation of the component in the vehicle. However, adhering the container to the porous layer is not strictly necessary to achieve this effect; this effect can also be achieved in other ways, for example, by shaping the container in a suitable manner and / or by fastening the container to the porous layer with some mechanical fastening elements.

[0149] Figure 3 is a schematic cross-sectional view of a noise-damping trim part (11) according to the present invention when installed on a vehicle body (14). When the part is installed on the vehicle body (14), the membrane contact surface (4) conforms to the shape of the vehicle body (14) itself, ensuring a tight seal with the vehicle body. Because the membrane is extremely thin and flexible, this also results in uneven areas of the vehicle body (14), as shown for the container at the far right of Figure 3. The membrane contact surface (4) is in close contact with the vehicle body (14) on one side and with the loose particles (3) on the other side, and is therefore able to transmit the vibrations of the vehicle body to the loose particles very efficiently.

[0150] Figure 4 is a schematic cross-sectional view of a noise-damping trim component according to the present invention similar to that shown in Figure 3, but for application to a vertical body panel. As shown in Figure 4, in such an application, the loose particles (3) tend to fill the lower portion of the container volume, but the particles still remain at least partially in contact with the membrane contact surface (4), and due to the granular nature of the particles, the total weight of the particles has a component perpendicular to the membrane. In the areas where the loose particles are in contact with the membrane contact surface (4), the membrane conforms to and remains in intimate contact with the vehicle body (14), thus transmitting vehicle body vibrations to the loose particles (3).

[0151] 1 to 4, the outer surface of the trim part, which is the vehicle body when the part is installed in the vehicle, consists only of the part belonging to the porous layer and the part belonging to the container. However, in the trim part according to the present invention, the outer surface part that comes into contact with the vehicle body when the part is installed in the vehicle may also include other parts that do not belong to either the porous layer or the container.

[0152] FIG. 5a shows an embodiment of a container (1) according to the present invention similar to that shown in FIGS. 1 to 4, in which the container has a parallelepiped shape and the container (5) has a small flange (6) along its edge.

[0153] The small flange (6) can help prevent the container (1) from sinking into the porous layer (7) during the integration process, however, proper and accurate integration of the container into the trim part is possible even without this flange.

[0154] Figures 5b and 5c show other embodiments of the container (1) according to the invention which differ from that shown in Figure 5a in terms of the shape of the container: Figure 5b is a schematic cross-sectional view of a hemispherical container, and Figure 5c is a schematic cross-sectional view of a container having the shape of an inverted truncated cone.

[0155] In particular, the embodiment shown in FIG. 5c is an example of a "self-clamping" shape, i.e., a shape in which the container, once inserted into the porous layer (7), cannot simply fall out due to gravity. Other shapes with the same properties (e.g., an inverted truncated pyramid, a barrel-shaped shape) are possible and will be apparent to those skilled in the art. All of these shapes advantageously simplify the embedding of the container (1) in the porous layer (7). However, other measures can also be used to prevent the container (1) from falling out of the porous layer (7), for example, by gluing the container (1) to at least part of the surface of the porous layer (7) or by providing the container with some kind of mechanical fixing element.

[0156] FIG. 6 is a schematic cross-sectional view of a 3D-formed noise-damping trim part (19) according to the present invention. In this figure, for simplicity, all the containers have the same parallelepiped shape and the same size. The containers may have any other type of shape and different sizes, depending on manufacturing convenience. The number and location of the containers preferably correspond to the areas of the vehicle body where vibrations are highest, i.e., the so-called "hot spots," which can be identified by testing or simulation methods known in the art. Preferably, the total surface area of the container walls in contact with the vehicle body (when the part is installed in a vehicle) is much smaller than the total surface area of the outer surface of the trim part in contact with the vehicle body (when the part is installed in a vehicle). This ensures that embedding the containers does not adversely affect the sound-insulating and absorbing performance of the trim part.

[0157] FIG. 7 is a schematic top view of a vehicle floor (20) cut from a body in white (BIW). The vehicle floor is made of 0.8 mm thick steel. Tests were performed in the front left area (21) of the floor, also referred to here as the test area (21). This area is indicated by a dashed rectangle in the figure, and different configurations of trim components were located there. The locations of the loose particle container (23) and the damping pad (24) are shown in the same figure, but tests were performed separately for the configuration with a conventional damping pad and the configuration with the component embedded with a container partially filled with loose particles according to the present invention. During the tests, the floor was excited using an electrodynamic shaker at an excitation point (22) located in the left front corner of the vehicle floor. The excitation signals were recorded under actual driving conditions and spanned a frequency bandwidth of 50 to 700 Hz.

[0158] Three configurations were tested: configurations 1 and 2 are state of the art, and configuration 3 is according to the invention. Configuration 1 is a trim part made of a porous fibrous layer facing and in contact with the vehicle floor and a mass layer facing away from the floor. The porous fibrous layer is 20 mm thick and has a mass of 1700 g / m 2 It has an area weight of 2.8 kg / m² and is made of 20% BicoPET / CoPET and 80% recycled cotton, with the recycled cotton containing 40% recycled fibres. The mass layer is 2 mm thick and has a weight of 2.8 kg / m². 2 It is an EPDM layer with an areal weight of

[0159] Configuration 2 is the same trim part as configuration 1, but with three additional damping pads (24) laminated to the vehicle floor, the damping pads (24) being positioned between the vehicle floor and the porous fibrous layer of the trim part. The damping pads (24) are 2 mm thick and have an areal weight of 4 kg / m. 2 Each damping pad weighs 50 grams. The area of one damping pad is 128cm. 2, and the three damping pads cover a portion of the test area (21) as shown in FIG.

[0160] Configuration 3 is a trim part similar to configuration 1, but with three containers partially filled with loose particles according to the invention embedded in a porous fibrous layer, as shown for example in Figure 3. Each container is a parallelepiped box, in which the container part, i.e., the side walls and the wall facing away from the vehicle floor, is made of polypropylene having a thickness of 2.0 mm, while the closure part, i.e., the wall facing and in contact with the vehicle floor, is made of thin foil. This foil has a thickness of 27 mm. μm PA / PE membrane with an area weight of 38g / m 2 The tensile modulus is 250 MPa. The internal volume of each chamber is 20 cubic centimeters (5 × 5 × 0.8 cm), and the median particle size is 400 μm , and partially filled with 42 grams of steel particles with a particle size distribution span of about 2. These values were selected to have good performance primarily over a frequency range above 250 Hz. The total weight of one container with steel particles is 50 grams. A trim part with an integrated container according to configuration 3 is placed on the test area (21) so that the part is placed directly on the vehicle floor (unglued, not locally glued where the container is located) and in contact with the vehicle floor (unglued). The porous fibrous layer is 20 mm thick and the total height of the container is about 11 mm, which means that in the area where the container with loose particles is located, there is about 9 mm of porous fibrous material between the container and the mass layer.

[0161] Figure 8 shows the measured average vibration velocity level per unit excitation force [(m / s) / N] for various configurations. Floor vibration velocity levels were measured for each configuration on the steel side by eight accelerometers attached to the underside of the test area (16) and distributed evenly over its surface.

[0162] A lower vibration level is desirable since a higher vibration level amplitude means higher noise within the vehicle.

[0163] Figure 8 shows the average vibration levels measured on a vehicle floor in the 1 / 3 octave between 100 Hz and 630 Hz. The vibration levels at each frequency are the average of eight measurement points where accelerometers were attached to the steel floor (car body). Due to the floor reinforcement provided by the damping pads, Configuration 1 without the damping pads shows the highest levels except for frequencies below 200 Hz where Configuration 2 shows the highest levels. Configuration 3 with a container partially filled with loose particles shows the lowest levels at the same weight as Configuration 2, especially in the range above 250 Hz.

[0164] The principles of each configuration can of course be applied to the entire floor, not just the test area (21). The invention disclosed herein includes the following aspects: [1] An automotive noise-damping trim component having at least one porous layer, the porous layer comprises at least one sealed container partially filled with loose particles, the sealed container having a contact surface formed by a membrane for contacting a vibration surface of a vehicle, and a surface of the membrane opposite the contact surface contacting at least a portion of the loose particles, thereby enabling the membrane to transfer vibration energy from the vibration surface to the loose particles in the container. Automotive noise damping trim parts. [2] The noise-damping trim part for an automobile according to [1] above, wherein the container comprises a container portion and a closure portion connected together to form a sealed container for maintaining a defined void volume. [3] The noise-damping trim part for an automobile according to [2] above, wherein the closing portion comprises a membrane for contacting the vibration surface and for contacting at least a portion of the loose particles, and preferably the closing portion consists of the membrane. [4] The noise-damping trim part for an automobile according to any one of [1] to [3] above, wherein the total volume of the loose particles in the container is less than 90% of the total internal volume of the sealed container, preferably 30% to 85%, and more preferably 40% to 70%. [5] The noise-damping trim part for an automobile according to any one of the above [1] to [4], wherein the discrete particles have a median particle size of 20 μm to 1250 μm, preferably 250 μm to 1000 μm, preferably 350 μm to 700 μm. [6] The noise-damping trim part for an automobile according to any one of [1] to [5] above, wherein the loose particles are made of at least one material selected from the group consisting of inert minerals such as calcium carbonate or silicon dioxide, metals such as steel, ceramic materials, elastomeric materials such as styrene-butadiene rubber, nitrile rubber, ethylene propylene diene monomer-derived rubber (EPDM) and butyl rubber or natural rubber, and polymeric materials such as polystyrene, and combinations of these materials. [7] The noise-damping trim part for an automobile according to any one of [1] to [6] above, wherein the total weight of the particles in one container is less than 100 grams, preferably 5 to 100 grams, and preferably 10 to 50 grams. [8] The noise-damping trim part for an automobile according to any one of the above [1] to [7], wherein the film has a thickness of 10 μm to 1 mm, preferably 40 μm to 700 μm, and preferably 60 μm to 300 μm. [9] A noise-damping trim part for an automobile according to any one of the above [2] to [8], wherein the container portion (5) has an edge portion with a protruding flange (6) having a width of at least 1 mm.

[10] The automotive noise-damping trim part according to any one of [1] to [9] above, wherein the porous layer comprises a maximum of 30 containers, preferably 4 to 30 containers, more preferably 8 to 20 containers.

[11] The noise-damping trim part for an automobile according to any one of the above [1] to

[10] , wherein the porous layer is one of an open-cell foam layer or a fiber felt layer.

[12] The noise-damping trim part for an automobile according to

[11] above, wherein the fibrous felt layer comprises fibers and / or filaments and further comprises a thermosetting or thermoplastic binder.

[13] A noise-damping trim part for an automobile according to any one of [1] to

[12] above, further comprising one or more additional layers on the surface of the porous layer opposite to the surface that contacts the vibration surface of the vehicle.

[14] The automotive noise-damping trim part according to

[13] above, wherein the at least one or more additional layers are at least one of a foam layer, or a decorative layer such as a felt layer, a film layer, a foil layer, a thermoplastic elastomer layer with a high filler content, a nonwoven layer or a carpet layer, or any combination of such layers.

[15] A method for producing an automotive noise-damping trim part according to any one of [1] to

[14] above, comprising at least the following steps: (a) forming a container portion having a defined interior volume, preferably using at least thermoforming, blow molding, vacuum forming, injection molding, or compression molding, or by additive manufacturing or 3D printing; (b) filling the defined internal volume with discrete particles; (c) laminating a closure part at least partially provided with said membrane for said contact surface on the rim of said container part to obtain a closed container filled with loose particles; (d) producing a porous layer having a recess that fits the shape of the container; (e) inserting the container into the recess of the porous layer;

[16] Use of the noise-damping trim part for an automobile according to any one of [1] to

[15] above as an inner dash, an outer dash, a battery lid silencer, a battery housing insulator, and / or a carpet system such as a tufted carpet, a needle-punched carpet, a carpet with a flocked surface, or a Dilour carpet, a trunk trim part, or a trim part for an engine bay area, wherein the porous layer is a layer that contacts a vibrating body panel when the part is installed in a vehicle.

Claims

1. 1. A noise-damping trim component for an automobile comprising at least one porous layer, the porous layer comprises at least one sealed container partially filled with loose particles, the sealed container having a contact surface formed by a membrane for contacting a vibration surface of a vehicle, and a surface of the membrane opposite to the contact surface contacting at least a portion of the loose particles, thereby enabling the membrane to transfer vibration energy from the vibration surface to the loose particles in the container. Automotive noise damping trim parts.

2. 10. The automotive noise-damping trim component of claim 1, wherein the container comprises a container portion and a closure portion connected together to form a sealed container for maintaining a defined void volume.

3. 3. The automotive noise-damping trim component of claim 2, wherein the closure comprises a membrane for contacting the vibration surface and contacting at least a portion of the loose particles, and preferably the closure consists of the membrane.

4. 4. A noise-damping trim part for an automobile according to any one of claims 1 to 3, wherein the total volume of the loose particles in the container is less than 90%, preferably 30% to 85%, preferably 40% to 70% of the total internal volume of the sealed container.

5. A noise-damping trim part for an automobile according to any one of claims 1 to 4, wherein the discrete particles have a median particle size of 20µm to 1250µm, preferably 250µm to 1000µm, preferably 350µm to 700µm.

6. 6. The noise-damping trim part for an automobile according to any one of claims 1 to 5, wherein the loose particles are made of at least one material selected from the group consisting of inert minerals such as calcium carbonate or silicon dioxide, metals such as steel, ceramic materials, elastomeric materials such as styrene-butadiene rubber, nitrile rubber, ethylene propylene diene monomer derived rubber (EPDM) and butyl rubber or natural rubber, and polymeric materials such as polystyrene, and combinations of these materials.

7. A noise-damping trim part for an automobile according to any one of claims 1 to 6, wherein the total weight of the particles in one container is less than 100 grams, preferably between 5 and 100 grams, preferably between 10 and 50 grams.

8. A noise-damping trim part for an automobile according to any one of the preceding claims, wherein the film has a thickness of from 10 μm to 1 mm, preferably from 40 μm to 700 μm, preferably from 60 μm to 300 μm.

9. A noise-damping trim part for an automobile according to any one of claims 2 to 8, wherein the container part (5) has a rim with a protruding flange (6) having a width of at least 1 mm.

10. A noise-damping trim part for an automobile according to any one of the preceding claims, wherein the porous layer comprises up to 30 reservoirs, preferably 4 to 30 reservoirs, more preferably 8 to 20 reservoirs.

11. 11. The noise-damping trim part for an automobile according to any one of claims 1 to 10, wherein the porous layer is one of an open-cell foam layer or a fiber felt layer.

12. 12. The automotive noise-damping trim component of claim 11, wherein the fibrous felt layer comprises fibers and / or filaments and further comprises a thermosetting or thermoplastic binder.

13. 13. The automotive noise-damping trim part of claim 1, further comprising one or more additional layers on a surface of the porous layer opposite the surface that contacts the vibration surface of the vehicle.

14. 14. The automotive noise-damping trim component of claim 13, wherein the at least one or more additional layers are at least one of a foam layer, or a decorative layer such as a felt layer, a film layer, a foil layer, a high filler content thermoplastic elastomer layer, a nonwoven layer, or a carpet layer, or any combination of such layers.

15. A method for manufacturing an automotive noise-damping trim part according to any one of claims 1 to 14, comprising at least the following steps: (a) forming a container portion having a defined interior volume, preferably using at least thermoforming, blow molding, vacuum forming, injection molding, or compression molding, or by additive manufacturing or 3D printing; (b) filling the defined internal volume with discrete particles; (c) laminating a closure part at least partially provided with said membrane for said contact surface onto the rim of said container part to obtain a closed container filled with loose particles; (d) producing a porous layer having a recess that fits the shape of the container; (e) inserting the container into the recess of the porous layer;

16. Use of the noise-damping trim part for an automobile according to any one of claims 1 to 14 as an inner dash, an outer dash, a battery lid silencer, a battery housing insulator, and / or a carpet system such as a tufted carpet, a needle-punched carpet, a carpet with a flocked surface, or a Dilour carpet, a trunk trim part, or a trim part for an engine bay area, wherein the porous layer is the layer that contacts a vibrating body panel when the part is installed in a vehicle.

Images