Acoustic fiber decoupler
阅读说明：本技术 声学纤维解耦器 (Acoustic fiber decoupler ) 是由 戴尔芬·吉涅 劳拉·戈塔尔多 格雷戈里·威尼格 托马索·德尔佩罗 于 2018-06-14 设计创作，主要内容包括：用于交通工具的模制三维噪声衰减装饰部件,至少包括三层系统,所述三层系统由第一多孔纤维层和第二多孔纤维层以及位于所述第一多孔纤维层和第二多孔纤维层之间的透气中间膜层组成,并且其中所述三层系统内的相邻表面是相互连接的,其中,所述第二多孔纤维层具有在表面上变化的面积重量AW2,并且其中至少对于总厚度t在5到35mm之间的三层系统的区域来说,所述面积重量AW2与所述三层系统的总厚度t相关如下：25*t+175<AW2<45*t+475,其中t的单位为mm并且AW2的单位为g.m-2,并且其中所述第二多孔纤维层的面积重量AW2随着所述三层系统的总厚度t的增加而增加。(Molded three-dimensional noise-attenuating trim part for vehicles, comprising at least a three-layer system consisting of a first and a second porous fibrous layer and an air-permeable intermediate membrane layer located between the first and second porous fibrous layers, and wherein adjacent surfaces within the three-layer system are interconnected, wherein the second porous fibrous layer has an area weight AW2 that varies over the surface, and wherein the area weight AW2 is related to the total thickness t of the three-layer system at least for regions of the three-layer system having a total thickness t between 5 and 35mm as follows: 25 × t +175< AW2<45 × t +475, wherein t is in mm and AW2 is in g.m-2, and wherein the areal weight AW2 of the second porous fibrous layer increases with increasing total thickness t of the three-layer system.)
1. Molded three-dimensional noise-attenuating trim part for vehicles, comprising at least a three-layer system consisting of a first and a second porous fibrous layer and an air-permeable intermediate membrane layer located between the first and second porous fibrous layers, and wherein adjacent surfaces within the three-layer system are interconnected, characterized in that the second porous fibrous layer has an area weight AW2 that varies over the surface, and wherein the area weight AW2 is related to the total thickness t of the three-layer system at least for regions of the three-layer system having a total thickness t between 5 and 35mm as follows: 25 × t +175<AW2<45 x t +475, wherein t is in mm andAW2 has the unit g.m-2And wherein the areal weight AW2 of the second porous fibrous layer increases with increasing total thickness t of the three-layer system.
2. The molded three-dimensional noise attenuating trim component of any one of the preceding claims, wherein each of the first and second porous fibrous layers has a particle size between 300 and 4000g.m-2An areal weight of between 300 and 3000g.m is preferred-2Preferably between 300 and 2050g.m-2In the meantime.
3. The molded three-dimensional noise attenuating trim part of any one of the preceding claims, wherein at least the second layer has a compressive stiffness of at least 3.5kPa, preferably between 5 and 25 kPa.
4. The molded three-dimensional noise-attenuating trim part of any one of the preceding claims, wherein the three-layer system has a total airflow resistance between 500 and 10000ns.m-3Preferably between 1000 and 7000ns.m-3Preferably between 2000 and 6000ns.m-3In the meantime.
5. Molded three-dimensional noise attenuating trim part according to any one of the preceding claims, wherein the overall air flow resistance and the overall density of the three-layer system are at least for an area of the three-layer system having a total thickness t between 5 and 35mm
6. The molded three-dimensional noise attenuating trim part of any one of claims 1 to 4, wherein at least for an overall density higher than 160kg/m3The overall air flow resistance and the overall density of the three-layer system
7. The molded three-dimensional noise attenuating trim part of any one of the preceding claims, wherein the air flow resistance of the first porous fibrous layer and the intermediate membrane layer together comprises at least 55%, preferably between 65% and 80% of the total air flow resistance of the three-layer system, and/or wherein the air flow resistance of the intermediate membrane layer is higher than the total air flow resistance of the first and second porous fibrous layers.
8. The molded three-dimensional noise attenuating trim component of any one of the preceding claims, wherein the first and second porous fibrous layers comprise fibers made of at least one material selected from the group consisting of: polyamides (nylons), such as polyamide 6 or polyamide 66; polyesters, such as copolymers of polyesters or polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) or polytrimethylene terephthalate (PTT); polyolefins, such as polypropylene or polyethylene, such as copolymers of polyethylene; and mineral fibers, preferably one of glass fibers or recycled glass fibers or basalt fibers or carbon fibers.
9. The molded three-dimensional noise attenuating trim part of any one of the preceding claims, wherein at least one of the first and second porous fibrous layers, preferably at least the second porous fibrous layer, comprises self-wound crimped fibers, preferably hollow self-wound crimped fibers.
10. The molded three-dimensional noise attenuating trim component of any one of the preceding claims, wherein at least one of the first and second porous fibrous layers comprises remanufactured fibers made from at least one material selected from the group consisting of: cotton recyclates, synthetic recyclates, polyester recyclates, natural fiber recyclates, and mixed synthetic and natural fiber recyclates.
11. The molded three-dimensional noise attenuating trim component of any one of the preceding claims, wherein the first and second porous fibrous layers comprise a thermoplastic binder material made of at least one material selected from the group consisting of: polyesters such as polyethylene terephthalate, copolymers of polyesters, polyolefins such as polypropylene or polyethylene, polylactic acid and polyamides such as polyamide 6 or polyamide 66.
12. The molded three-dimensional noise attenuating trim component of any one of the preceding claims, wherein the breathable intermediate film layer comprises at least one layer comprising at least one of a polymer or copolymer selected from the group consisting of: polyesters, such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) or copolyesters (CoPES); polyamides, such as polyamide 6 or polyamide 66; polyolefins, such as Polyethylene (PE) or Low Density Polyethylene (LDPE) or Linear Low Density Polyethylene (LLDPE) or High Density Polyethylene (HDPE); ethylene acrylic acid copolymer (EAA); polypropylene (PP); thermoplastic elastomers (TPEs), such as Thermoplastic Polyolefins (TPOs); thermoplastic Polyurethane (TPU); a polyetherimide; polysulfones; polyether sulfone; polyether ether ketone; and copolymers such as Ethylene Vinyl Acetate (EVA), or biopolymers such as polylactic acid.
13. Molded three-dimensional noise attenuating trim part according to any one of the preceding claims, further comprising at least a covering scrim layer, an acoustic scrim layer, a decorative top layer, such as a tufted carpet or a non-woven carpet.
14. Use of the molded three-dimensional noise attenuating trim part of any of the preceding claims as an interior trim part such as an interior instrument panel barrier and/or floor carpet.
15. Method for manufacturing a molded three-dimensional noise attenuating trim part according to any one of the preceding claims, comprising the steps of:
a. preparing at least one second unconsolidated or preconsolidated porous fibrous layer having a surface area weight that varies, wherein the layer is made by laying down fibers and binder material into a product-forming cavity;
b. preparing an unconsolidated or pre-consolidated first porous fibrous layer;
c. stacking a membrane layer and the first and second unconsolidated or pre-consolidated fibrous layers in a mold with any optional additional layers, with the membrane layer being between the first and second porous fibrous layers;
d. the material is consolidated in the mold and the layers are laminated together by a consolidation process, preferably hot air, steam or infrared heating, in which the thermoplastic binder softens and/or melts, binds the fibers together and/or optionally to adjacent layers.
Technical Field
The present invention relates to noise-attenuated automotive interior trim parts, such as interior instrument panel partitions and floor mats, for use in vehicles, particularly passenger cars.
Background
There are many sources of noise in vehicles, such as noise from the powertrain, tire noise, brake noise, and wind noise. The noise generated by these different sources enters the vehicle passenger compartment and may cover a fairly wide frequency range.
For noise attenuation in vehicles, particularly cars and trucks, it is well known to use trim components such as isolators and absorbers to reflect and dissipate noise and thereby reduce the overall internal noise level.
Noise attenuating trim components (also referred to herein as trim components such as interior instrument panel partitions and floor carpet systems) are molded into three-dimensional shapes so as to follow the shape of the vehicle body when installed in the vehicle. The three-dimensional shape of the trim part can be very strong and the thickness of the trim part can vary from a few millimeters up to about 100 millimeters.
In addition to acoustic performance requirements, these trim parts should also provide a certain overall stiffness, so that the parts can be handled more easily, for example during assembly, and a local stiffness, such as tread (tread) strength, so that, for example, when standing on the trim part, for example when stepping into or out of a vehicle, it is not too soft or springs back too much when pressed on the trim part.
These trim parts may comprise a foam and/or fabric felt layer and are usually made of a decoupling layer facing the vehicle body and at least a top layer facing away from the vehicle body.
These trim parts are typically manufactured by placing a pre-manufactured felt layer having a uniform areal weight in a mold and establishing the shape of the trim part during compression.
A pre-felt layer (so-called billet) with more or less uniform areal weight and thickness on the surface. The density of the layer varies across the surface of the trim component, at least after compression to form the component. For acoustic and weight saving reasons, at least decoupling layers of very low areal weight can be chosen. On the other hand, in order to provide sufficient rigidity and pedal strength, at least a decoupling layer of higher areal weight may be required, especially in some thicker areas of the trim part. Selecting a layer with a higher and uniform areal weight can compromise acoustic performance in some thinner regions of the trim part where high areal weight is not desired, and is then too high for acceptable acoustic performance.
The use of a felt layer according to the state of the art has other drawbacks. In particular, the felt tends to decrease in its thickness during use of the trim part and/or particularly during manufacturing processes where fibers are additionally used. The noise attenuation of a trim part comprising such a fibre layer and also having a film is thus reduced.
It is therefore an object of the present invention to further optimize state of the art fibrous noise attenuating trim part products and in particular to further optimize the overall acoustic performance of the part.
Disclosure of Invention
The object of the present invention is achieved by a molded three-dimensional noise-attenuating trim part for a vehicle according to claim 1, comprising at least a three-layer system consisting of a first and a second porous fibrous layer and an air-permeable intermediate membrane layer located between the first and second porous fibrous layers, and wherein adjacent surfaces within the three-layer system are interconnected, wherein the second porous fibrous layer has an area weight AW2 that varies over the surface, and wherein the area weight AW2 is related to the total thickness t of the three-layer system at least for the area of the three-layer system with a total thickness t between 5 and 35mm as follows: 25 × t +175<AW2<45 × t +475, wherein t is in mm and AW2 is in g.m-2And wherein the areal weight AW2 of the second porous fibrous layer increases with increasing total thickness t of the three-layer system.
The adjacent surfaces of the three layers are interconnected, wherein the adjacent surfaces of the layers are joined over substantially the entire surface.
The second porous fibrous layer has an area weight AW2 which varies across the surface and should be understood to vary across the surface outside of the normal product variation (which is about +/-10%).
The second porous fibrous layer (also referred to herein as the second layer) may have a substantially constant density at varying thicknesses. Constant density or constant areal weight should be understood as constant within normal product variations.
Preferably, the second porous fibrous layer is a decoupling layer, also referred to as a decoupler, that faces the body of the vehicle when installed in the vehicle. The first porous fibre layer is preferably the top layer of the three-layer system facing away from the vehicle body. A breathable intermediate film layer is positioned between the first and second porous fibrous layers.
However, other additional layers may be located on top of the first porous fibrous layer (top layer), such as a cover scrim layer, an acoustic scrim layer, a decorative top layer, e.g. tufted carpet or nonwoven carpet.
The three-layer system is breathable and no other layer is positioned between the first porous fibrous layer and the breathable film layer or between the second porous fibrous layer and the breathable film layer.
The trim part or the three-layer system is thus three-dimensional in the sense of having a shape adapted to follow the shape of the vehicle body when mounted in the vehicle. The thickness of the trim part and the three-layer system can vary strongly over the surface.
The term "over the surface" is to be understood as extending over the main surface of the respective layer and/or of the three-layer system.
Surprisingly, by using the 3-layer system according to the invention, in particular by a combination of a first fibrous layer, a breathable membrane layer and a second porous fibrous layer (decoupler layer), wherein the areal weight of the second fibrous layer is optimized with respect to the total thickness of the complete 3-layer system according to the invention, the noise attenuation properties of trim parts, such as carpet systems for vehicles, can be improved. With a lower areal weight for the second fibrous layer in the regions of the trim part having a lower overall thickness and a higher areal weight for the second fibrous layer in the regions having a higher overall thickness. Further, by optimizing the areal weight of the second layer in certain regions having a higher thickness, the strength of the pedal can be improved. Surprisingly, this increases the acoustic performance independently of the areal weight of the first fibrous layer, however, in addition to the desired effect, this layer can also have an effect on the overall acoustic performance.
Too low an areal weight of the second porous layer may impair the rigidity of the trim part and may not contribute significantly further to a better noise attenuation below a certain areal weight. An excessively high areal weight of the second porous layer may reduce the noise attenuation performance and also unnecessarily increase the weight of the trim part.
For regions with a total thickness of the three-layer system between 5 and 35mm, the upper limit 45 t +475 and the lower limit 25 t +175 of the areal weight AW2 (where t is in mm and AW2 is in g.m.) for the second porous fibrous layer according to the invention were applied (where t is in mm and AW2 is in g.m.)-2) Too low and/or too high areal weights can be avoided and a noise-attenuating decorative part according to the invention with good noise-attenuating properties can be achieved compared to decorative parts in which the second porous fibrous layer (decoupling layer) has an areal weight outside these limits.
These area weight-thickness relationships guide the technician to find the correct area weight, allowing the design of trim components with a balanced compromise between noise attenuation performance and compression stiffness. In addition to ensuring a certain minimum compressive stiffness, the area weight lower limit also indicates the minimum amount of material suitable to better fill the very thick regions of the decoupler.
By using a second fiber layer having an areal weight within the upper and lower limits of AW2 according to the invention, in particular, an excessively high areal weight in thin regions can be avoided, and excessively high and low areal weights in thicker regions can be avoided.
If a certain minimum compressive stiffness of the second layer is required, the compressive stiffness should be checked, for example by measurement according to current ASTM D3574-05 test C with modifications as described below, and if too low, the areal weight in this region can be increased in order to increase the compressive stiffness. However, the increased area weight should not be outside the area weight-thickness relationship according to the present invention.
The steps may be to first ensure that AW2 of the second porous fibrous layer is within the upper and lower limits according to the invention, and then check the compressive stiffness. The area weight in the desired area is increased if necessary and the compression stiffness and area weight are rechecked to be within the upper and lower limits according to the invention. These steps may be repeated if desired.
By applying this area weight-thickness relationship when designing the trim part, the weight of the trim part can be reduced with the same acoustic performance or the acoustic performance can be increased for the same weight compared to trim parts according to the state of the art.
The areal weight of the second porous fibrous layer can be calculated for a localized region of the three-layer system, wherein the total thickness t of the three-layer system is measured. A local area of the three-layer system is cut perpendicular to the direction of the layers to obtain a part of the three-layer system. The first porous fibrous layer and the intermediate breathable film layer may be removed from the second layer, and the areal weight of the second layer may be estimated separately. The calculation of the areal weight of the local region may be repeated for different regions of the three-layer system.
Each of the first and second fibrous layers preferably has a thickness in the range of 300 and 4000g.m-2An areal weight of between 300 and 3000g.m is preferred-2Preferably between 300 and 2050g.m-2In the meantime.
Typically, by increasing the weight of the first layer, noise attenuation can be improved, but at the expense of heavier trim components. However, by optimizing the second porous fibrous layer (decoupling layer) according to the invention, the noise attenuation can be further improved, or the weight of the top layer can be reduced with the same acoustic performance.
Preferably, the second layer is less compressed and/or thicker than the first layer, and wherein the second porous fibrous layer closely follows the shape of the vehicle body. The thinner, more compressed first layer increases the airflow resistance of the tri-layer system and trim component.
Preferably, the thickness of the second layer is 30-95%, preferably 50-90%, of the total thickness of the three-layer system, and wherein the thickness of the first layer is between 1 and 15mm, preferably between 2 and 10 mm.
The stiffness of the noise attenuating trim component depends not only on the stiffness of the individual layers, but also on the number of layers in the area where the stiffness is estimated. However, an important feature of the overall stiffness of the trim component is the compressive stiffness of the second porous fibrous layer.
Preferably, at least the second porous fibrous layer has a compressive stiffness of at least 3.5kPa, preferably between 5 and 25kPa, measured according to current ASTM D3574-05 test C with the following modification. ASTM D3574-05 test C relates to foam materials, but is also commonly used in the automotive industry for porous fibrous materials due to the lack of suitable test methods for porous fibrous materials.
The size and thickness of the samples are also different from the ASTM D3574-05 test C standards, and smaller and thinner sample sizes are used. The measurements were made on disc-shaped samples having a diameter of 60mm and a thickness down to 5 mm.
The Air Flow Resistance (AFR) of the individual layers and the overall air flow resistance of the three-layer system and of the trim part can be further optimized for the noise attenuation of the trim part.
In order to have a high performance noise attenuating trim part, the AFR of the trim part should preferably not be too high in order not to reflect most of the noise, but should also preferably not be too low, as the layers and parts may then not absorb enough noise.
Preferably, the total air flow resistance of the trilayer system is between 500 and 10000ns.m-3Preferably between 1000 and 7000ns.m-3Preferably between 2000 and 6000ns.m-3Measured according to the current ISO9053 using the direct air flow method (method a).
The current ISO9053 using the direct air flow method (method a) is used for all AFR values disclosed.
Preferably, the overall air flow resistance and the overall density of the three-layer system are such that, at least for the region of the three-layer system having a total thickness t of between 5 and 35mm
Preferably, at least for bulk densities, higher than 160kg/m3The overall air flow resistance and the overall density of the three-layer system
The noise attenuating trim part according to the invention also remains open for layers with a high density, ensuring optimum acoustic performance.
Bulk density of a portion of a part
The bulk density is calculated for the local region of the component where the bulk air flow resistance is measured. A local area of the component is cut perpendicular to the direction of the layers to obtain a portion of the component on which the overall areal weight and/or density is measured.
The relationship between density and air flow resistance as defined and claimed is area dependent and therefore mixing of different sites will result in an incorrect data set.
The overall Air Flow Resistance (AFR) is the AFR measured over a localized area of the trim component. It is clear to the skilled person that the average over a certain small area will also follow the teaching of the invention as disclosed, since the measurement of density and AFR is done over an area and not at the level of a single point. The AFR is measured according to ISO9053 using the direct air flow method (method a).
The overall density and overall AFR are variable across the part or surface due to the typical shape of the part and the materials used. To define the minimum area to measure these quantities, ISO9053 defines the smallest circular area with a diameter of 95mm that must be used. However, when the 3D shape of the component is particularly pronounced in some cases, the skilled person may deviate from the limits of the specification and measure samples having a small circular area of no less than 75mm diameter, if necessary, provided that the tool for measurement of AFR is adapted to provide a suitable air flow through this local area of the component. For such samples, it is recommended that the thickness variation on the surface of the sample be maintained within a range of about 20%. For example, it is acceptable to measure a sample having a thickness of 5mm with a local deviation between 4 and 6mm (and not outside this range), or a sample having a thickness of 10mm with a local deviation between 8 and 12 mm.
Due to the impedance differences between the three layers of the three-layer system, the noise attenuation and in particular the noise absorption is improved.
Preferably, the air flow resistance of the first porous fibrous layer and the middle membrane layer together account for at least 55%, preferably between 65% and 80%, of the total AFR of the three-layer system.
Preferably, the AFR of the middle membrane layer is higher than the total AFR of the first and second porous fibrous layers.
The first and second porous fibrous layers comprise fibers and preferably a thermoplastic binder material.
Preferably, the first and second porous fibrous layers comprise fibers made of at least one material selected from the group consisting of: polyamides (nylons), such as
Preferably, at least one of the first and second porous fibrous layers, preferably at least the second porous fibrous layer, comprises self-wound crimped fibers, preferably hollow self-wound crimped fibers.
Surprisingly, the use of self-rolling crimped fibers in combination with a thermoplastic binder makes it possible to increase the thickness at lower densities while maintaining or even improving the acoustic performance. This allows for better filling of the available space without adding extra weight to the component.
Self-curling crimped fibers are side-by-side conjugate fibers, also known as bicomponent fibers. Self-curling crimped fibers, also known as crimped, bent or self-curling fibers, are made of composite fibers, for example, by two sides, and are configured such that one side shrinks differently than the other, resulting in a permanent bend-forming of the fiber away from a straight line, for example in the form of a coil, omega or spiral. However, in most cases, the shapes are not necessarily regular structures, but versions of irregular 3-dimensional shapes have the same advantages.
Preferably, the composite material is selected such that there is a difference in viscosity, resulting in inherent coiling or curling in the fibers. However, other types of composite fibers may be selected which exhibit similar effects as defined.
Surprisingly, the addition of self-rolling crimped fibers to the porous fiber layer enhances the uniformity of the material layer obtained by, for example, a carding process or more preferably a fiber injection process. The natural tendency of self-rolling crimped fibers to return to a random crimped form imparts additional elasticity to the fibers. For example, open fibers do not re-form clumps during the processing process and are therefore better dispersed throughout the layer.
Surprisingly, the material as claimed can be thermoformed more accurately in a 3D shape, and furthermore the elasticity of the material is not substantially reduced during curing or moulding, indicating that self-wound crimped fibres are not prone to degradation during the curing or moulding process of the actual component. Furthermore, the porous fiber layer comprising the self-wound crimped fibers retains its elasticity during use, and thus the initial thickness directly obtained after molding is maintained longer.
Self-wound crimped fibers are different from mechanically crimped fibers in that they acquire the ability to crimp during spinning of the fiber as an inherent feature of the fiber. This inherent self-coiling of crimped fibers is less likely to be lost during further manufacturing process steps or subsequent use of the material. The crimp in a self-wound crimped fiber is permanent.
The advantages of using self-rolling crimped fibers rather than mechanically crimped fibers are manifold. The most important advantage for the disclosed invention is that the fibers are in a crimped state from the start of the manufacture of the fiber layer. The crimped state in the form of random 3-dimensional shaped fibers is a preferred state of the fibers. Surprisingly, the fibers remain in this preferred shape throughout the manufacturing and during the service life of the trim part. Mechanical crimping is inherently less strong and loses its properties over time. The mechanically crimped fibers will flatten out over time, losing elasticity and loft, rendering the trim part ineffective in its use over time.
Self-wound crimped fibers may also be made from a combination of polymers such as different polyesters, for example a combination of polyethylene terephthalate (PET) and polytrimethylene terephthalate (PTT).
Preferably, the self-wound crimped fiber has an overall circular cross-section, more preferably a hollow core, also known as a hollow composite fiber. However, other cross-sections known in the art may be used to make the composite self-wound crimped fiber.
The staple length of the crimped fibers used is preferably between 32 and 76mm, preferably 32 to 64 mm. The fibres are preferably between 2 and 28 dtex, preferably between 3 and 15 dtex, preferably between 3 and 10 dtex.
The binder material should have a lower melting point than the polymer from which the self-wound crimped fiber is made, so only the binder melts during manufacture, rather than the self-wound crimped fiber.
Surprisingly, the preferred combination of cotton fibers and self-wound crimped fibers bonded together using binder fibers shows an increase in compressive stiffness, thereby improving overall performance. Due to the higher compression stiffness, the noise attenuating trim part will not decrease in its thickness during use.
Preferably, at least one of the first and second porous fibrous layers comprises remanufactured fibers made from at least one material selected from the group consisting of: cotton recyclates, synthetic recyclates, polyester recyclates, natural fiber recyclates, and mixed synthetic and natural fiber recyclates.
The recycled fibers are preferably made of textile fabrics, preferably recycled cotton, recycled synthetic, recycled polyester or recycled natural fibers. The regeneration type is defined as having at least 51% by weight of the included material, 49% may be fibers from other sources. Thus, for example, the recycled polyester comprises at least 51% by weight of polyester-based material. Alternatively, the recycled material may be a mixture of different synthetic and natural fibers, whereby no one type is dominant.
Any of the fibers, self-rolling crimped fibers, binder fibers, remanufactured fibers, synthetic fibers, natural fibers or mineral fibers are staple fibers and may be made from virgin and/or recycled materials.
Preferably, the first and second porous fibrous layers comprise a thermoplastic adhesive material made of at least one material selected from the group consisting of: polyesters such as polyethylene terephthalate, copolymers of polyesters, polyolefins such as polypropylene or polyethylene, polylactic acid (PLA) and polyamides such as
Preferably, the binder material is in the form of fibers, flakes or powder. More preferably, the binder material is one of a monocomponent fiber or a bicomponent fiber.
In the case of binder fibres, the length is preferably between 32 and 76mm, preferably 32 to 64 mm. The binder fibers are preferably between 2 and 5 dtex.
In one embodiment according to the invention, at least one of the first and second porous fibrous layers comprises filler fibres and self-wound crimped fibres, and wherein at least one of the first and second porous fibrous layers consists essentially of 10 to 40% of thermoplastic binder material, 10 to 70% of filler fibres and 10 to 70% of self-wound crimped fibres, and wherein the total amount is increased to 100% by weight.
Filler fibers are understood to be any fibers that are not self-wound crimped fibers or binder materials.
In another embodiment according to the invention, at least one of the first and second porous fibrous layers comprises filler fibers and self-wound crimped fibers, and wherein at least one of the first and second porous fibrous layers consists essentially of 10 to 40% thermoplastic binder, 10 to 40% filler fibers and 10 to 60% self-wound crimped fibers and 10 to 50% shredded foam pieces, and wherein the total amount is increased to 100% by weight.
Preferably, the BICO fibers are used with hollow composite self-wound crimped fibers and cotton recyclates. Preferably, the BICO fibers are polyester/CoPET.
Preferably, the shredded foam is a polyurethane foam, preferably a flexible polyurethane foam. The density of the foam is preferably between 10 and 100kg.m-3Preferably between 20 and 90kg.m-3Preferably between 25 and 85kg.m-3In the meantime. The size of the chopped foam pieces is preferably between 2 and 20mm, preferably between 3 and 15mm, preferably between 4 and
Preferably, the breathable intermediate film layer (also referred to herein as a film layer) comprises at least one layer comprising at least one polymer or copolymer selected from the group consisting of: polyesters, such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) or copolyesters (CoPES); polyamides, such as
The breathable intermediate film layer may also be referred to as intermediate film layer, film layer or foil and should be understood as a thin layer, preferably having a thickness of at least 15 microns, preferably between 15 and 100 microns, preferably between 15 and 50, preferably between 15 and 30 microns.
Preferably, the areal weight of the film layer is less than 200g.m-2Preferably less than 100g.m-2。
Preferably, a bi-layer or multi-layer film may be used, wherein the film layer may also serve as an adhesive layer for laminating the first and second porous fiber layers together. Preferably, the film layer is a three layer film having a core with a higher melting temperature than the outer layer. The outer layers melt during manufacture and bond the core layer of the film to the first and second porous fibrous layers.
The gas-permeable membrane may be pre-perforated, for example by needles, and/or made gas-permeable during moulding of the three-layer system, for example by the action of hot steam and/or by needles integrated in the moulding process.
The breathable film layer may be a glue, powder, foil, film, coating, etc., which retains the film layer or becomes a film-type layer during the manufacture of the noise attenuating component. The membrane layer may also be softened and/or melted during manufacture and mixed with the binder of the first and/or second porous fibrous layers.
For either the fiber or the film layer, the polymer used may be virgin or based on recycled material, as long as the material requirements are met.
Preferably, the three-dimensional noise attenuating trim part according to the invention further comprises at least a covering scrim layer, an acoustic scrim layer, a decorative top layer, such as a tufted carpet or a non-woven carpet.
The molded three-dimensional noise attenuating trim component according to the present invention may be used as an interior trim component such as an interior instrument panel barrier and/or floor mat.
Preferably, the molded three-dimensional noise attenuating trim part according to the present invention is manufactured as follows.
The method for manufacturing a molded three-dimensional noise attenuating trim part according to the invention comprises the steps of:
a) preparing at least one second unconsolidated or preconsolidated porous fibrous layer having a surface area weight that varies, wherein the layer is prepared by laying down a mixture of fibers and binder material into a product-forming cavity.
b) A first porous fibrous layer is prepared that is unconsolidated or pre-consolidated.
c) Stacking a membrane layer and the first and second unconsolidated or pre-consolidated fibrous layers in a mold with the membrane layer between the first and second porous fibrous layers. Optionally, additional layers may be placed below and/or on top of the three layers.
d) The material is consolidated in the mold and the layers are laminated together by a consolidation process, preferably hot air, steam or infrared heating, in which the thermoplastic binder softens and/or melts, binds the fibers together and/or optionally to adjacent layers.
An unconsolidated or pre-consolidated second porous fibrous layer having a varying areal weight according to the invention can be manufactured, for example, by using the machine disclosed in EP 2640881, wherein a fibrous mixture comprising a binder is fed into the cavity in the form of the final product, thereby forming a porous fibrous layer shape that contains the thickness variations necessary to have a varying areal weight on the surface of the layer. The density of the porous fibrous layer may remain substantially constant throughout the filling process. The second porous fibrous layer may be pre-consolidated directly on the machine, as disclosed in the cited patents, or may be consolidated later.
The first fibrous layer may be manufactured into a mat or blank using methods known to those skilled in the art, such as carded cross-lapping or air-laying.
The term "consolidation" or "consolidated" should be understood as a process during the manufacture of the noise attenuating component and/or individual layers in which the fiber layers are heated and the thermoplastic binder softens and/or melts, thereby bonding the fibers together and/or optionally to adjacent layers.
Pre-consolidation is understood to be the case where the above-mentioned consolidation process has started but not yet been completed, and the case where the fibers are weakly attached to each other, thereby giving the porous fiber layer some stability for handling and reducing fiber loss during handling. Consolidation may be accomplished in a second step, wherein the fibers are suitably bonded during consolidation as described above.
Area weight, density and thickness can be measured using standard methods known in the art.
Any given range should include the beginning and end points as well as the normally expected deviation in measurement. The starting and ending values of the different ranges may be combined.
Further embodiments of the invention may also be derived from the description by combining different embodiments and examples of the invention, and also from the description of the embodiments shown in the drawings. The figures are schematic and not necessarily drawn to scale.
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