Sustainable sound-absorbing nonwoven fabric

Abstract

To provide sustainable sound-absorbing nonwoven fabrics with a low area density, and a method for producing the same.SOLUTION: There is provided a thermally solidified sound-absorbing nonwoven fabric having a fluid resistance of 150 Ns / m3 to 5000 Ns / m3, measured in accordance with DIN EN 29053, May 1993, and an area density of 150 g / m2 to 600 g / m2. The nonwoven fabric includes c) structural staple fibers having a mean titer of 0.9 dtex to 8.8 dtex, in a proportion of 50 wt.-% to 90 wt.-% in relation to an overall weight of the nonwoven fabric, and d) core-sheath binding fibers in a proportion of 10 wt.-% to 50 wt.-% in relation to the overall weight of the nonwoven fabric. The structural staple fibers include a percentage of reprocessed structural staple fibers and the core-sheath binding fibers include a percentage of reprocessed core-sheath binding fibers.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a sustainable sound absorbing nonwoven fabric with a low basis weight. The present invention further relates to a method for producing the same and to its use.

[0002] Sound-absorbing nonwoven fabrics are used in a variety of applications. One important field of use is as sound absorbers in the automotive industry. EP 3246442 A1 states: a) at least one open-pore support layer comprising thick staple fibers having an average fineness of 3 dtex to 17 dtex and, as framework fibers, thin staple fibers having an average fineness of 0.3 dtex to 2.9 dtex, in particular 0.5 dtex to 2.9 dtex; b) a microporous fluidized bed disposed on the support layer and containing microfibers having a fiber diameter of less than 10 μm; The sound-absorbing textile composite has a flow resistance of 250 Ns / m 3 ~5000Ns / m 3 , especially 250Ns / m 3 ~2000Ns / m 3 The support layer may contain sheath-core fibers as the bonding fibers.

[0003] Advantageously, the sound absorbing material combines good acoustic properties with a low basis weight, and is advantageously produced at least in part from sustainable resources.

[0004] One approach to producing sustainable sound-absorbing materials is to use recycled fiber materials as raw materials. However, commercially available sound-absorbing materials of this type have a very uneven appearance. Furthermore, they generally have low sound absorption capacity, so they are usually sold in sizes of 600 g / m². 2 This runs counter to the increasing efforts to achieve desirable lightweight construction for automobiles.

[0005] Another approach is the use of r-PET fibers obtained from recycled PET bottles. This approach certainly allows the desired sound absorption to be achieved with a lighter material. However, as PET bottles will become an increasingly scarce resource in the future, other sustainable fiber alternatives are needed to produce efficient sound-absorbing materials. Therefore, an object of the present invention is to provide a sustainable sound-absorbing material that does not require the use of r-PET fibers obtained from recycled PET bottles as a raw material source and that has good acoustic and mechanical properties. A further object is to provide a method for producing such a sound-absorbing material and its use.

[0006] The challenge is to achieve a load of 150 Ns / m, measured in accordance with DIN EN 29053, May 1993 edition. 3 ~5000Ns / m 3 , advantageously 150 Ns / m 3 ~3000Ns / m 3 , and even more preferably 150 Ns / m 3 ~2000Ns / m 3 , especially 150Ns / m 3 ~1000Ns / m 3 and a flow resistance of 150g / m 2 ~600g / m 2 and a basis weight of the thermal bonded sound absorbing nonwoven fabric, a) comprising 50% to 90% by weight, preferably 60% to 80% by weight, and even more preferably 70% to 80% by weight, of framework staple fibers with an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, relative to the total weight of the nonwoven fabric; and b) the nonwoven fabric contains core-sheath type binder fibers in an amount of 10% by weight to 50% by weight, preferably 20% by weight to 40% by weight, and even more preferably 20% by weight to 30% by weight, based on the total weight of the nonwoven fabric; The problem is solved by a thermally bonded sound absorbing nonwoven fabric in which the framework staple fibers include a proportion of chopped framework staple fibers and the sheath-core binder fibers include a proportion of chopped sheath-core binder fibers.

[0007] It has been found that nonwoven fabrics according to the present invention have very good acoustic and mechanical properties, despite the proportion of chopped fibers. Chopped fibers are fibers obtained through a mechanical process (shredding) to break down the structure of textile waste. The observed good acoustic and mechanical properties were surprising, since fibers are typically subjected to very high mechanical stresses during the shredding process, resulting in partial destruction. Additionally, the chopped fibers contained in prior art nonwoven fabrics have a wide range of fiber lengths, with a proportion of short fibers and a proportion of unbroken thread-like or sheet-like material fragments. This results in a significantly different property profile compared to primary fibers. This, in particular, would have been expected to result in a deterioration in acoustic properties. It was particularly surprising that the sheath of the chopped sheath-core binder fibers could be sufficiently remelted a second time during nonwoven fabric production, thereby enabling bonding.

[0008] As explained above, shredded fibres are fibres obtained from textile waste through a shredding process, which is a mechanical process to break down the structure of the textile waste. The aim of this process is to recover the fibres contained in the textile waste and reuse them as raw material for a new manufacturing cycle.

[0009] The crushing process is described, for example, in Hilmar Fuchs, Wilhelm Albrecht, Vliesstoffe: Rohstoffe, Herstellung, Anwendung, Eigenschaften, Prüfung (18. Juli 2012), zweite Ausgabe, Wiley VCH.

[0010] On the other hand, primary fibers are fibers according to the present invention that have not been recycled through a crushing process. Crushed fibers can be distinguished from primary fibers by having a damaged fiber structure, which is visually recognizable. This is manifested, for example, in the crushed framework fibers, by an irregular or completely destroyed crimp structure and / or uneven fiber lengths. Crushed binder fibers also have binder components that are at least partially destroyed at least before being remelted, which is manifested by an irregular fiber shape. When crushed sheath-core binder fibers are thermally bonded, as in the nonwoven fabrics according to the present invention, these fibers can be distinguished, for example, from thermally bonded primary sheath-core binder fibers by having a more irregular structure, in which, for example, two cores are surrounded by a common sheath, or the sheath is deformed, for example, agglomerated.

[0011] Figure 1 shows a photograph of the primary framework fibers. The fibers exhibit strong, uniform crimp. Figure 2 shows a photograph of the crushed framework fibers. The fibers exhibit significantly less crimp and are more irregular. Figure 3 shows an SEM image of the fused primary binder fibers. The fibers exhibit a relatively regular fiber profile. The irregularity is due solely to the melting of the binder components and the shedding of some of the framework fibers. This shedding is due to the sample preparation, in which a section of the nonwoven fabric was cut away, resulting in the fibers being pulled out. Figure 4 shows an SEM image of the crushed binder fibers (not refused). The partially broken binder components are clearly visible. Figure 5 shows an SEM image of the refused crushed binder fibers. The two cores are clearly surrounded by a common sheath.

[0012] Furthermore, micrographs of examples of nonwoven fabrics according to the present invention revealed that the nonwoven fabrics according to the present invention had less uniform fiber distribution than nonwoven fabrics of the same structure containing only primary fibers. For example, the crushed core-sheath binder fibers were found to form "nested fibers" in which the proportion of binder fibers was higher than in other parts of the nonwoven fabric. Figure 6 shows a nonwoven fabric according to the present invention with white-colored nested fibers. For comparison, Figure 7 shows a nonwoven fabric containing only primary fibers and no nested fibers.

[0013] A nonwoven fabric is a structure made of fibers of limited length, continuous fibers (filaments), or chopped yarns of any type and origin, bound in any way to form a web (fiber layer, fiber batt), which is then bound together in any way, excluding the crossing and entanglement of yarns that occurs in the production of woven fabrics, warp knitting, weft knitting, lacemaking, braiding, and tufted goods. Nonwoven fabrics do not include films or papers. Nonwoven fabrics are described in DIN EN ISO 9092, August 2019 edition.

[0014] According to the invention, the nonwoven fabric comprises framework staple fibers having an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, in a proportion of 50% to 90% by weight, preferably 60% to 80% by weight, even more preferably 70% to 80% by weight, based on the total weight of the nonwoven fabric, and the framework staple fibers comprise a proportion of chopped framework staple fibers.

[0015] Framework staple fibers should be understood to mean staple fibers that are different from the binder components of binder fibers and do not exist in a fused state with their fiber components. This is the usual meaning of framework fibers. Preferably, core-sheath binder fibers are also staple fibers. Staple fibers should be understood to mean fibers having a predetermined length, as opposed to theoretically infinite filaments, as is customary in the art.

[0016] According to the present invention, the framework staple fibers comprise a proportion of chopped framework staple fibers, wherein the chopped framework staple fibers have an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex. In a preferred embodiment of the present invention, the chopped framework staple fibers have an average staple length of 5 mm to 60 mm, even more preferably 10 mm to 55 mm, in particular 10 mm to 50 mm.

[0017] In a further preferred embodiment of the present invention, the chopped framework staple fibers comprise at least one melt-spinnable polymer. Preferably, the polymer is selected from polyacrylonitrile, polyvinyl alcohol, viscose, polyamide, especially polyamide 6 and polyamide 6.6, polyolefin and / or polyester. Preferred are polyolefin and / or polyester. Very particular preference is given to polyester.

[0018] Particularly preferably, the chopped framework staple fibers comprise at least one polyester selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate, poly(decamethylene) terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyglycolic acid, polylactide, polycaprolactone, polyethylene adipate, polyhydroxyalkanoates, polyhydroxybutyrate, poly-3-hydroxybutyrate-co-3-hydroxyvalerate, polytrimethylene terephthalate, Vectran, polyethylene naphthalate, copolymers thereof, and / or mixtures thereof. Particularly preferred polyesters are polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, and mixtures and / or copolymers thereof. Particularly preferably, the chopped framework staple fibers comprise polyethylene terephthalate. In that case, the chopped framework staple fibers preferably comprise from 50% to 100% by weight, even more preferably from 70% to 100% by weight, even more preferably from 80% to 100% by weight of the aforementioned polymers, in particular polyethylene terephthalate, based on the total weight of the chopped framework staple fibers, and in particular consist of the polymers mentioned herein.

[0019] In a preferred embodiment, the nonwoven fabric comprises primary framework staple fibers in addition to chopped framework staple fibers, the primary framework staple fibers advantageously having an average fineness of 0.9 dtex to 8.8 dtex, even more preferably 0.9 dtex to 6.7 dtex, especially 0.9 dtex to 3.3 dtex. If present, the primary framework staple fibers preferably have an average staple length of 20 mm to 80 mm, even more preferably 25 mm to 80 mm, especially 30 mm to 80 mm.

[0020] In a further preferred embodiment of the present invention, the primary framework staple fibers comprise at least one melt-spinnable polymer. Preferably, the polymer is selected from polyacrylonitrile, polyvinyl alcohol, viscose, polyamide, especially polyamide 6 and polyamide 6.6, polyolefin and / or polyester. Preferred are polyolefin and / or polyester. Very particular preference is given to polyester.

[0021] Particularly preferably, the primary framework staple fibers comprise at least one polyester selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate, poly(decamethylene) terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyglycolic acid, polylactide, polycaprolactone, polyethylene adipate, polyhydroxyalkanoates, polyhydroxybutyrate, poly-3-hydroxybutyrate-co-3-hydroxyvalerate, polytrimethylene terephthalate, Vectran, polyethylene naphthalate, copolymers thereof, and / or mixtures thereof. Particularly preferred polyesters are polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, mixtures and / or copolymers thereof. Particularly preferably, the primary framework staple fibers comprise polyethylene terephthalate. In that case, the primary framework staple fibers preferably comprise from 50% to 100% by weight, even more preferably from 70% to 100% by weight, even more preferably from 80% to 100% by weight of the aforementioned polymers, in particular polyethylene terephthalate, based on the total weight of the primary framework staple fibers, and in particular consist of the polymers named herein.

[0022] According to the present invention, the nonwoven fabric contains 10% by weight to 50% by weight, preferably 20% by weight to 40% by weight, and even more preferably 20% by weight to 30% by weight of the core-sheath binder fibers relative to the total weight of the nonwoven fabric, and the core-sheath binder fibers contain a certain proportion of crushed core-sheath binder fibers.

[0023] Binder fibers are understood to mean fibers having at least one binder component present in the form of a more or less distorted fiber structure or a completely fused continuous phase. The binder component can provide adhesive bonding for sheet-like structures. In core-sheath binder fibers, the sheath acts as the binder component.

[0024] Also preferably, the chopped sheath-core binder fibers have an average fineness in the range of 1.7 dtex to 6.7 dtex, advantageously 1.7 dtex to 5 dtex.

[0025] Preferably, the fractured core-sheath binder fibers have a core polymer (core polymer) that is different from the sheath polymer. After solidification, the core polymer may be partially or completely surrounded by the binder component. The quantitative ratio of the core polymer to the sheath polymer can be freely selected. A ratio of 90:10 to 10:90 (weight ratio of core:sheath in weight percent), even more preferably 80:20 to 20:80, even more preferably 80:20 to 30:70, and in particular 80:20 to 40:60 has proven particularly advantageous.

[0026] According to a particularly preferred embodiment, the sheath polymer of the fractured sheath-core binder fiber has a lower melting point than the core polymer of the fractured sheath-core binder fiber, where the difference between the melting temperature of the sheath polymer and the melting temperature of the core polymer is advantageously at least 5° C., preferably at least 8° C., and particularly preferably at least 10° C. This difference in the melting temperatures of the two polymers provides good temperature stability.

[0027] The core polymer of the fractured core-sheath binder fibers can comprise a wide variety of materials. Preferably, the core polymer is a melt-spinnable polymer. Preferably, the polymer is selected from polyacrylonitrile, polyvinyl alcohol, viscose, polyamide, particularly polyamide 6 and polyamide 6.6, polyolefin, and / or polyester. Preferred are polyolefin and / or polyester. Very particularly preferred are polyesters.

[0028] Particularly preferably, the core polymer comprises at least one polyester selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate, poly(decamethylene) terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyglycolic acid, polylactide, polycaprolactone, polyethylene adipate, polyhydroxyalkanoate, polyhydroxybutyrate, poly-3-hydroxybutyrate-co-3-hydroxyvalerate, polytrimethylene terephthalate, Vectran, polyethylene naphthalate, copolymers thereof, and / or mixtures thereof. Preferred polyesters are polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, as well as mixtures and / or copolymers thereof. Particularly preferably, the core polymer comprises polyethylene terephthalate. In this case, the core polymer preferably comprises from 50% to 100% by weight, more preferably from 70% to 100% by weight, more preferably from 80% to 100% by weight of the aforementioned polymer, in particular polyethylene terephthalate, based on the total weight of the core polymer, and in particular consists of the polymers mentioned herein.

[0029] When the nonwoven fabric comprises primary sheath-core binder fibers, the core polymer of the chopped sheath-core binder fibers advantageously has the same polymer and / or polymers as the core polymer of the primary sheath-core binder fibers.

[0030] The sheath polymer of the fractured core-sheath binder fibers can similarly comprise a wide variety of materials. Preferably, the sheath polymer comprises a copolyester, in particular a copolyethylene terephthalate. Suitable copolymers include, for example, random copolymers, gradient copolymers, alternating copolymers, block copolymers, and graft polymers. The copolymers can consist of two, three, four, or more different monomers (terpolymers, tetrapolymers). Particularly preferred additional comonomers are those of the following polymers: aromatic and aliphatic polyesters, aromatic and aliphatic polyamides, aromatic and aliphatic epoxides, aromatic and aliphatic polyurethanes, polysiloxanes, polyacrylates, and polyacrylamides.

[0031] In this case, the sheath polymer of the chopped sheath-core binder fiber contains copolyethylene terephthalate in an amount of preferably 50% by weight to 100% by weight, even more preferably 70% by weight to 100% by weight, and even more preferably 80% by weight to 100% by weight, based on the total weight of the sheath polymer of the chopped sheath-core binder fiber.

[0032] When the nonwoven fabric comprises primary sheath-core binder fibers, the sheath polymer of the chopped sheath-core binder fibers advantageously has the same polymer(s) as the sheath polymer of the primary sheath-core binder fibers.

[0033] Preferably, the sheath polymer of the fractured core-sheath binder fibers has a melting point in the range of less than 250°C, even more preferably in the range of 70 to 235°C, even more preferably in the range of 125 to 225°C, and particularly preferably in the range of 150 to 225°C.

[0034] When the nonwoven fabric comprises primary framework fibers and / or primary sheath / core binder fibers, the chopped sheath / core binder fibers advantageously have the same average fineness and / or the same polymer as the primary sheath / core binder fibers and / or the chopped framework fibers have the same average fineness and / or the same polymer as the primary framework fibers.

[0035] In a preferred embodiment, the nonwoven fabric comprises primary sheath-core binder fibers.

[0036] The primary sheath-core binder fibers are preferably staple fibers, preferably having an average staple length of from 20 mm to 80 mm, even more preferably from 25 mm to 80 mm, especially from 30 mm to 80 mm.

[0037] Also preferably, the primary sheath-core binder fibers have an average fineness ranging from 1.7 dtex to 6.7 dtex, advantageously from 1.7 dtex to 5 dtex.

[0038] According to the present invention, the primary sheath-core binder fiber preferably has a core polymer (core polymer) that is different from the sheath polymer. The quantitative ratio of the core polymer to the sheath polymer can be freely selected. Ratios of 90:10 to 10:90 (core:sheath weight ratio in weight %), even more preferably 80:20 to 20:80, even more preferably 80:20 to 30:70, and especially 80:20 to 40:60 have proven particularly advantageous.

[0039] According to a particularly preferred embodiment, the sheath polymer of the primary sheath-core binder fiber has a lower melting point than the core polymer of the primary sheath-core binder fiber, where the difference between the melting temperature of the sheath polymer and the melting temperature of the core polymer is advantageously at least 5° C., preferably at least 8° C., and particularly preferably at least 10° C. This difference in the melting temperatures of the two polymers provides good temperature stability.

[0040] The core polymer of the primary sheath-core binder fiber can comprise a wide variety of materials. Preferably, the core polymer is a melt-spinnable polymer. Preferably, the polymer is selected from polyacrylonitrile, polyvinyl alcohol, viscose, polyamide, particularly polyamide 6 and polyamide 6.6, polyolefin, and / or polyester. Preferred are polyolefin and / or polyester. Very particularly preferred are polyesters.

[0041] Particularly preferably, the core polymer comprises at least one polyester selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate, poly(decamethylene) terephthalate, poly-1,4-cyclohexylene dimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyglycolic acid, polylactide, polycaprolactone, polyethylene adipate, polyhydroxyalkanoate, polyhydroxybutyrate, poly-3-hydroxybutyrate-co-3-hydroxyvalerate, polytrimethylene terephthalate, Vectran, polyethylene naphthalate, copolymers thereof, and / or mixtures thereof. Particularly preferred polyesters are polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, as well as mixtures and / or copolymers thereof. Particularly preferably, the core polymer comprises polyethylene terephthalate. In this case, the core polymer preferably comprises from 50% to 100% by weight, more preferably from 70% to 100% by weight, more preferably from 80% to 100% by weight of the aforementioned polymer, in particular polyethylene terephthalate, based on the total weight of the core polymer, and in particular consists of the polymers mentioned herein.

[0042] The sheath polymer of the primary sheath-core binder fibers can likewise comprise a wide variety of materials. Preferably, the sheath polymer comprises a copolyester, in particular a copolyethylene terephthalate. Suitable copolymers include, for example, random copolymers, gradient copolymers, alternating copolymers, block copolymers, and graft polymers. The copolymers can consist of two, three, four, or more different monomers (terpolymers, tetrapolymers). Particularly preferred additional comonomers are those of the following polymers: aromatic and aliphatic polyesters, aromatic and aliphatic polyamides, aromatic and aliphatic epoxides, aromatic and aliphatic polyurethanes, polysiloxanes, polyacrylates, and polyacrylamides.

[0043] In this case, the sheath polymer of the primary sheath / core binder fiber preferably contains copolyethylene terephthalate in an amount of 50% by weight to 100% by weight, more preferably 70% by weight to 100% by weight, and even more preferably 80% by weight to 100% by weight, based on the total weight of the sheath polymer of the primary sheath / core binder fiber.

[0044] Preferably, the sheath polymer of the primary sheath-core binder fiber has a melting point in the range of less than 250°C, even more preferably in the range of 70 to 235°C, even more preferably in the range of 125 to 225°C, and particularly preferably in the range of 150 to 225°C.

[0045] In a preferred embodiment of the present invention, the nonwoven fabric contains chopped fibers in an amount of 8% to 100% by weight, more preferably 10% to 80% by weight, even more preferably 15% to 70% by weight, and particularly preferably 20% to 60% by weight, based on the total weight of the sound-absorbing nonwoven fabric. A high proportion of chopped fibers is advantageous in terms of sustainability.

[0046] In a further embodiment of the invention, the nonwoven fabric comprises primary fibers in an amount of less than 15% by weight, preferably less than 10% by weight, in particular less than 5% by weight, each relative to the total weight of the sound-absorbing nonwoven fabric. In a further embodiment of the invention, the nonwoven fabric does not comprise primary fibers.

[0047] In a further embodiment of the invention, the nonwoven fabric comprises framework staple fibers having an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, in a proportion of 60% to 80% by weight, and even more preferably 70% to 80% by weight, relative to the total weight of the nonwoven fabric.

[0048] In a further embodiment of the present invention, the nonwoven fabric comprises sheath-core binder fibers in an amount of 20% to 40% by weight, and even more preferably 20% to 30% by weight, based on the total weight of the nonwoven fabric.

[0049] In a further preferred embodiment of the present invention, the nonwoven fabric comprises primary fibers in an amount of 5% to 92% by weight, still more preferably 20% to 90% by weight, still more preferably 30% to 85% by weight, and in particular 40% to 80% by weight, each relative to the total weight of the sound-absorbing nonwoven fabric.

[0050] More preferably, the proportion of crushed framework staple fibers relative to the total weight of framework staple fibers is 10 to 100% by weight, preferably 15% to 80% by weight, even more preferably 20% to 70% by weight, especially 20% to 60% by weight.

[0051] Also preferably, the proportion of the crushed sheath-core binder fibers relative to the total weight of the sheath-core binder fibers is 10% by weight to 100% by weight, preferably 20% by weight to 75% by weight, even more preferably 30% by weight to 80% by weight, and particularly preferably 40% by weight to 80% by weight.

[0052] In a further preferred embodiment, the nonwoven fabric comprises 5% to 90% by weight of crushed framework staple fibers, even more preferably 10% to 80% by weight, even more preferably 15% to 70% by weight, even more preferably 20% to 60% by weight, and in particular 20% to 50% by weight, based on the total weight of the sound-absorbing nonwoven fabric.

[0053] In a further preferred embodiment, the nonwoven fabric comprises 1% to 50% by weight of crushed sheath-core binder fibers, more preferably 5% to 40% by weight, even more preferably 7.5% to 30% by weight, and particularly preferably 10% to 20% by weight, based on the total weight of the sound-absorbing nonwoven fabric.

[0054] In a further preferred embodiment, the nonwoven fabric comprises, relative to the total weight of the nonwoven fabric, a) from 0% to 70% by weight, advantageously from 10% to 65% by weight, even more preferably from 20% to 55% by weight, especially from 30% to 45% by weight of primary framework staple fibers; b) 0% to 70% by weight, advantageously 5% to 60% by weight, even more preferably 10% to 50% by weight, especially 15% to 40% by weight of primary sheath-core binder fibers; c) 5% to 90% by weight, even more preferably 10% to 80% by weight, even more preferably 15% to 70% by weight, even more preferably 20% to 60% by weight, especially 20% to 50% by weight of crushed framework staple fibers; d) 1% to 50% by weight, even more preferably 5% to 40% by weight, even more preferably 7.5% to 30% by weight, especially 10% to 20% by weight of crushed sheath-core binder fibers; Includes:

[0055] The nonwoven fabric according to the invention has a compressive strength of 150 Ns / m, measured in accordance with DIN EN 29053, May 1993 edition. 3 ~5000Ns / m 3 , advantageously 150 Ns / m 3 ~3000Ns / m 3 , and even more preferably 150 Ns / m 3 ~2000Ns / m 3 , especially 150Ns / m 3 ~1000Ns / m 3 It has a flow resistance of

[0056] The nonwoven fabric according to the invention further preferably has a sound absorption coefficient of more than 0.35, preferably more than 0.4, measured at 1000 Hz in Alphacabin (DIN EN ISO 354:2003) at a thickness of 10 to 50 mm, even more preferably 10 to 35 mm, in particular 10 mm.

[0057] Furthermore, the nonwoven fabric according to the present invention has a density of 150 g / m 2 ~600g / m 2 , advantageously 200 g / m 2 ~550g / m 2 , and even more preferably 250 g / m 2 ~500g / m 2 It has a weight of

[0058] Advantageously, the nonwoven fabric according to the invention has a thickness, measured in accordance with DIN EN ISO 9073-2 (1997-02), method B and C, of ​​10 to 50 mm, even more preferably of 10 to 35 mm.

[0059] Further preferably, the nonwoven fabric according to the invention has a maximum tensile strength in the longitudinal direction (according to DIN EN ISO 9073-2, 2022-05) of 25N to 100N, even more preferably 30N to 100N, in particular 40N to 100N and / or a maximum tensile strength in the transverse direction (according to DIN EN ISO 9073-2, 2022-05) of 25N to 100N, even more preferably 30N to 100N, in particular 40N to 100N.

[0060] More preferably, the nonwoven fabric according to the invention has an internal strength of more than 0.5 N / 5 cm, for example from 0.5 N / 5 cm to 10 N / 5 cm, and / or from 0.5 N / 5 cm to 3 N / 5 cm, and / or from 0.5 N / 5 cm to 2.5 N / 5 cm, measured according to DIN 54310 1980.

[0061] In a further preferred embodiment, the sound-absorbing nonwoven fabric is produced from textile waste that has been treated in a crushing process such that the treated textile waste contains at least 70% by weight of textile single fibers, advantageously 70% to 100% by weight, even more preferably 80% to 100% by weight, and even more preferably 90% to 100% by weight, based on the total amount of treated textile waste. To determine the amount of textile single fibers, single fibers are manually separated from a sample (10 g) of the treated textile waste. At least 10 samples are taken and the results are averaged.

[0062] More preferably, the sound-absorbing nonwoven fabric is produced from textile waste that has been treated in a shredding process, and the treatment in the shredding process is carried out so that the amount of undisintegrated textile residues, such as neps and sheet-like material fragments, contained in the treated textile waste is less than 30% by weight, advantageously 0% to 30% by weight, advantageously 0% to 20% by weight, and even more preferably 0% to 10% by weight, based on the total amount of the treated textile waste. To determine the amount of undisintegrated textile residues, the undisintegrated textile residues are manually separated from a sample (10 g) of the treated textile waste. At least 10 samples are taken, and the results are averaged.

[0063] More preferably, the sound-absorbing nonwoven fabric is produced from textile waste that contains nonwoven fabric and has been treated in a shredding process, and particularly preferably from textile waste that contains more than 90% by weight of nonwoven fabric, for example, 90% to 100% by weight, and even more preferably, 95% to 100% by weight. Particularly preferably, the sound-absorbing nonwoven fabric is produced from textile waste that has been treated in a shredding process and is present in a state that has been sorted by type.

[0064] In a further preferred embodiment, the sound absorbing nonwoven fabric is made from treated textile waste, the treated textile waste comprising: a) comprising 50% to 90% by weight, preferably 60% to 80% by weight, and even more preferably 70% to 80% by weight, of framework staple fibers with an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, based on the total weight of the treated textile waste; and b) The core-sheath binder fibers are contained in an amount of 10% to 50% by weight, preferably 20% to 40% by weight, and more preferably 20% to 30% by weight, based on the total weight of the treated textile waste.

[0065] A further subject of the invention is a material having a resistance of 150 Ns / m, measured in accordance with DIN EN 29053 of the May 1993 edition. 3 ~5000Ns / m 3 , advantageously 150 Ns / m 3 ~3000Ns / m 3 , and even more preferably 150 Ns / m 3 ~2000Ns / m 3 , especially 150Ns / m 3 ~1000Ns / m 3 and a flow resistance of 150g / m 2 ~600g / m 2 A method for producing a sound-absorbing nonwoven fabric having a basis weight of I. Providing textile waste, said textile waste comprising: a) comprising 50% to 90% by weight, preferably 60% to 80% by weight, and even more preferably 70% to 80% by weight, of framework staple fibers with an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, relative to the total weight of the textile waste; and b) a step of including sheath-core binder fibers in an amount of 10% by weight to 50% by weight, preferably 20% by weight to 40% by weight, and more preferably 20% by weight to 30% by weight, based on the total weight of the textile waste; II. At least partially disintegrating the textile structure of the textile waste in a crushing process to obtain a treated textile waste comprising a proportion of crushed framework staple fibers and a proportion of crushed sheath-core binder fibers; III. Forming a nonwoven fabric from the treated textile waste; IV. A step of heat-treating the nonwoven fabric to obtain a sound-absorbing nonwoven fabric; The method includes:

[0066] Process steps I) to IV) are preferably carried out successively.

[0067] Advantageously, the method according to the invention produces a thermally bonded sound-absorbing nonwoven fabric, which nonwoven fabric comprises: a) comprising 50% to 90% by weight, preferably 60% to 80% by weight, and even more preferably 70% to 80% by weight, of framework staple fibers with an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, relative to the total weight of the nonwoven fabric; and b) the nonwoven fabric contains core-sheath type binder fibers in an amount of 10% by weight to 50% by weight, preferably 20% by weight to 40% by weight, and even more preferably 20% by weight to 30% by weight, based on the total weight of the nonwoven fabric; The framework staple fibers include a proportion of chopped framework staple fibers, and the sheath-core binder fibers include a proportion of chopped sheath-core binder fibers, and the sound-absorbing nonwoven fabric has a density of 150 g / m 2 ~600g / m 2 A thermal bonded sound absorbing nonwoven fabric having a basis weight of

[0068] More preferably, the method according to the present invention produces a thermally bonded acoustic nonwoven fabric according to one or more of the embodiments described herein.

[0069] of the method according to the present invention Process I. The method comprises providing textile waste, the textile waste comprising framework staple fibers having an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, in a proportion of 50% to 90% by weight, preferably 60% to 80% by weight, even more preferably 70% to 80% by weight, based on the total weight of the textile waste, and core-sheath binder fibers in a proportion of 10% to 50% by weight, preferably 20% to 40% by weight, even more preferably 20% to 30% by weight, based on the total weight of the textile waste. A wide variety of textile waste is suitable for the method according to the invention. Preferably, the textile waste comprises fibers according to one or more of the embodiments described for the sound-absorbing nonwoven fabric according to the invention.

[0070] The textile waste here can come from a wide variety of fields, such as clothing and technical textiles. Preferably, the textile waste comprises nonwoven fabrics. Particularly preferably, the textile waste comprises nonwoven fabrics in a proportion of more than 90% by weight, for example 90% to 100% by weight, and even more preferably 95% to 100% by weight, based on the total weight of the textile waste. The textile waste can also comprise woven fabrics and / or warp knitted fabrics. The textile waste is furthermore advantageously present in a state sorted by type. Furthermore, the textile waste can also be present as post-consumer textiles, as filament or yarn residues, or as strip-like material from the production of sheet-like materials. Mixtures of different forms are also possible.

[0071] After step I, Optional Step I.1 in which the textile waste is pre-shredded, advantageously by shredding.

[0072] Furthermore, after step I or step I.1, Optional Step I.2 This can be followed by optionally wetting and / or oiling the pre-shredded textile waste, which is beneficial for subsequent structural breakdown. Furthermore, it can reduce fiber friction, thereby reducing energy costs and fiber damage.

[0073] This method Process II. comprises at least partially disrupting the textile structure of the textile waste in a shredding process to obtain treated textile waste.

[0074] In a preferred embodiment, the shredding process is carried out in a shredder, the operating principle of which is that the textile waste is fed through a feed system having a conveying and clamping action to a shredding unit, preferably a rotating drum on which shredding elements are arranged. The rotating drum is preferably a shredding drum. The shredding elements are preferably pin-shaped, hook-shaped or tooth-shaped. Preferably, the shredding elements are formed as a set of saw teeth. The shredding elements grip the textile waste clamped by the feed system and at least partially shred its structure under the influence of tensile stress.

[0075] The textile waste can be subjected to the shredding process one or more times. However, only a portion of the textile waste can be subjected to the shredding process multiple times. Advantageously, the shredding process includes at least two shredding processes. For this purpose, the textile waste can be fed back to the same shredding unit after one shredding process in the shredding unit. However, multiple shredding units can also be arranged in series. The material can be transported between the shredding units by, for example, a sieve drum. In a preferred embodiment of the present invention, the number and fineness of the shredding elements arranged in the various shredding units are adapted to the progression of the structural breakdown of the textile waste.

[0076] The drawing system can comprise a pair of rolls or a combination of a rotating roll and a rigid trough. Preferably, the drawing system is configured as a trough drawing machine, in which the clamping points of the material are located at the corners of the trough. This is advantageous because it allows the clamping points of the material to be closer to the effective range of the crushing elements.

[0077] By adjusting various parameters of the shredding process, in particular the number of shredding units through which the textile waste passes, the desired structural breakdown of the textile waste can be adjusted.

[0078] Preferably, the textile structure of the textile waste is disintegrated to an extent that the treated textile waste contains at most 30% by weight of undisintegrated textile residues such as neps and sheet-like material fragments, advantageously 0% to 30% by weight, even more preferably 0% to 20% by weight, even more preferably 0% to 10% by weight. Advantageously, the textile structure of the textile waste is disintegrated to an extent that the treated textile waste contains at least 70% by weight of textile single fibers, advantageously 70% to 100% by weight, even more preferably 80% to 100% by weight, even more preferably 90% to 100% by weight, based on the total weight of the treated textile waste. As a result, the treated textile waste obtained in step II advantageously contains at least 70% by weight of textile single fibers, even more preferably 70% to 100% by weight, even more preferably 80% to 100% by weight, and even more preferably 90% to 100% by weight. More preferably, the treated textile waste obtained in step II contains undisintegrated textile residues, such as neps and sheet-like material fragments, in a proportion of less than 30% by weight, advantageously 0% to 30% by weight, even more preferably 0% to 20% by weight, and even more preferably 0% to 10% by weight, based on the total amount of treated textile waste. To determine the proportion of undisintegrated textile residues, the undisintegrated textile residues are manually separated from a sample (10 g). At least 10 samples are taken, and the results are averaged.

[0079] The treated textile waste obtained in step II can be further processed to improve its quality. For example, extensive cleaning can be carried out to reduce the proportion of short fibers and / or to separate out coarse and foreign materials. Furthermore, desired textile treatments can be applied, such as flame-retardant, anti-fungal and / or anti-static treatments.

[0080] In a preferred embodiment of the present invention, the treated textile waste obtained in step II. a) comprising 50% to 90% by weight, preferably 60% to 80% by weight, and even more preferably 70% to 80% by weight, of framework staple fibers with an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex, based on the total weight of the treated textile waste; and b) The core-sheath binder fibers are contained in an amount of 10% to 50% by weight, preferably 20% to 40% by weight, and more preferably 20% to 30% by weight, based on the total weight of the treated textile waste.

[0081] In a further preferred embodiment of the present invention, the treated textile waste obtained in step II. is a) 5% to 90% by weight, even more preferably 10% to 80% by weight, even more preferably 15% to 70% by weight, even more preferably 20% to 60% by weight, in particular 20% to 50% by weight of chopped framework staple fibers having an average fineness of 0.9 dtex to 8.8 dtex, advantageously 0.9 dtex to 6.7 dtex, in particular 0.9 dtex to 3.3 dtex; b) 1% to 50% by weight, even more preferably 5% to 40% by weight, even more preferably 7.5% to 30% by weight, especially 10% to 20% by weight of crushed sheath-core binder fibers; Includes:

[0082] After step II. Optional Step II.1 This step may be followed by mixing the treated textile waste obtained in step II. with primary framework staple fibers and / or primary sheath-core binder fibers to obtain treated textile waste containing primary fibers. Preferably, step II.1 provides the following components relative to the total weight of the treated textile waste: a) from 0% to 70% by weight, advantageously from 10% to 65% by weight, even more preferably from 20% to 55% by weight, especially from 30% to 45% by weight of primary framework staple fibers; b) 0% to 70% by weight, advantageously 5% to 60% by weight, even more preferably 10% to 50% by weight, especially 15% to 40% by weight of primary sheath-core binder fibers; c) 5% to 90% by weight, even more preferably 10% to 80% by weight, even more preferably 15% to 70% by weight, even more preferably 20% to 60% by weight, especially 20% to 50% by weight of crushed framework staple fibers; d) 1% to 50% by weight, even more preferably 5% to 40% by weight, even more preferably 7.5% to 30% by weight, especially 10% to 20% by weight of crushed sheath-core binder fibers; The treated textile waste is obtained, which comprises:

[0083] of the method according to the present invention Process III. In step II. or II.1, the treated textile waste is formed into a nonwoven fabric, which can be formed by various methods known to those skilled in the art, such as carding.

[0084] of the method according to the present invention Process IV. The nonwoven fabric obtained in step III is heat-treated to a strength of 150 Ns / m, measured in accordance with DIN EN 29053 of the May 1993 edition. 3 ~5000Ns / m 3 , advantageously 150 Ns / m 3 ~3000Ns / m 3 , and even more preferably 150 Ns / m 3 ~2000Ns / m 3 , especially 150Ns / m 3 ~1000Ns / m 3 and a flow resistance of 150g / m 2 ~600g / m 2 A sound-absorbing nonwoven fabric having a basis weight of 110°C to 220°C is obtained. As known to those skilled in the art, the basis weight can be adjusted by appropriately setting the basis weight when laminating the nonwoven fabric. The heat treatment is preferably carried out at a temperature of 110°C to 220°C, more preferably 120°C to 200°C. The heat treatment is more preferably carried out in a forced-air oven.

[0085] A further subject of the invention is a sound-absorbing nonwoven fabric produced by the method according to the invention.

[0086] A further subject of the present invention is the use of the sound-absorbing nonwoven fabric according to the invention for sound absorption in the automotive sector, in particular in automobile interiors. [Brief explanation of the drawings]

[0087] [Figure 1] FIG. 1 shows a photographic image of the primary framework fibers. [Figure 2] FIG. 1 shows a photographic image of fractured framework fibers. [Figure 3] FIG. 1 shows an SEM image of fused primary binder fibers. [Figure 4] FIG. 1 shows an SEM image of crushed binder fibers (not re-fused). [Figure 5] FIG. 1 shows an SEM image of re-fused crushed binder fibers. [Figure 6] FIG. 1 shows a nonwoven fabric according to the present invention having nested fibers. [Figure 7] FIG. 1 shows a nonwoven fabric containing only primary fibers and no nested fibers. [Figure 8] FIG. 1 shows the sound absorption coefficient of a nonwoven fabric according to the present invention in Alpha Cabin.

[0088] To determine the parameters used according to the invention, the following measurement methods are used: Test method for measuring sound absorption coefficient in a reverberation chamber (Alpha Cabin) Measurements are carried out in the Alpha Cabin in accordance with DIN EN ISO 354:2003. The test sample is placed directly on the floor and measured using a frame.

[0089] Determination of the percentage of crushed framework staple fibers and crushed sheath-core binder fibers in treated textile waste At least 10 samples (5 g) are taken from the treated textile waste. The fibers are separated by hand using tweezers. Sheath-core binder fibers with at least partially disrupted binder components are considered to be disrupted sheath-core binder fibers. Framework staple fibers with irregular or completely disrupted crimp structures are considered to be disrupted framework staple fibers.

[0090] Determining the percentage of crushed framework staple fibers and crushed sheath-core binder fibers in nonwoven fabrics Cut at least five samples from the nonwoven fabric. 2 ) are observed under a microscope (resolution shown in Figure 3). Sheath-core binder fibers with irregular structures, such as two cores surrounded by a common sheath, or where the sheath is distorted, e.g., agglomerated, are considered to be fractured sheath-core binder fibers. Framework staple fibers with irregular or completely disrupted crimp structures are considered to be fractured framework staple fibers.

[0091] Test method for nonwoven fabrics to measure basis weight The measurement is based on ISO 9073-1 (1989-07) and the area of ​​the measurement sample is 100 mm x 100 mm.

[0092] Test Method for Nonwoven Fabrics to Determine Thickness Complies with methods B and C of DIN EN ISO 9073-2 (1997-02).

[0093] Fiber fineness measurement Fiber diameters are measured using a microscope and corresponding software in accordance with DIN 53810 (1981-02) (Spun Yarn Fineness - Terminology and Measurement Principle). Four micropreparations are prepared from a total of more than 20 single fibers. For each micropreparation, the fibers are shortened to a length of approximately 2-3 mm with scissors and placed on a microscope slide using a specimen pin. The fiber diameters are then measured in μm using appropriate software and averaged. The averaged fiber diameters are then calculated using the following formula: Tt[dtex]=(π×d 2 ×ρ) / 400 This can be converted to fiber fineness Tt by d is the fiber diameter (μm), ρ is the fiber density (g / cm 3 )

[0094] Staple length measurement Select 10 fiber bundles from the existing fiber sample, and measure the fiber length of the 10 single fibers by using tweezers to remove one single fiber from each of the 10 fiber bundles and clamping one free fiber end in one of the two clamps and the other fiber end in the other clamp. Turn the hand wheel to stretch the fiber until it is straight. Read the fiber length from the scale on the measuring device and record it in mm. The average of all the recorded results will indicate the staple length: SP [mm] = (ΣL) / n ΣL Sum of individual fiber lengths n The number of random samples.

[0095] Melting point measurement According to DIN EN ISO 11357-3(2018-07) "Differential scanning calorimetry (DSC) - Part 3: Determination of melting and crystallization temperatures and enthalpies of melting and crystallization" with a heating rate of 10 K / min.

[0096] Maximum transverse / longitudinal tensile force (according to DIN EN ISO 9073-3, 2022-05) The maximum tensile force is measured as follows: A tensile testing machine conforming to DIN 51220 (2003) and DIN EN ISO 7500 (2018) and a 260 x 50 mm punch are used.

[0097] Sample preparation: Measurement samples are punched out from the existing test sample, evenly across the width of the fabric, 10 cm from each edge in both the machine and machine directions.

[0098] implementation: After clamping the measurement sample evenly and vertically in the center, the test is carried out according to the machine-specific operating instructions, and the sample is pulled at the specified pulling speed of 200 mm / min with a preload of 0.5 N.

[0099] Internal strength of nonwoven fabric according to DIN 54310 (1980) Unlike the standard, the nonwoven fabric is separated parallel to the surface so that the resulting legs can be clamped in the clamps of the tensile tester.

[0100] Test method for measuring flow resistance According to DIN EN 29053 (1993-05), method A (cocurrent air flow method), the effective sample diameter corresponds to 100 mm and the air pressure to 1000 mbar.

[0101] The present invention will now be described in more detail with reference to the following non-limiting examples.

[0102] Example 1: The textile waste used is a sound-absorbing material consisting of 80% by weight of 1.7 dtex PET fibers (framework staple fibers, 38 mm) and 20% by weight of 4.4 dtex PET / CoPET (core-sheath binder fibers). This textile waste is moistened and re-fibered in a shredder equipped with a sawtooth set as a shredding element to obtain treated textile waste. This treated textile waste contains less than 15% by weight of undisintegrated textile residue. This treated textile waste is formed into a nonwoven fabric using a carding machine, and then heat-treated to a density of 250 g / m. 2 , a new sound-absorbing material with a thickness of 10 mm is manufactured. The obtained sound-absorbing material has a sound resistance of 153 Ns / m 3and has a sound absorption coefficient as shown in Figure 8, measured in accordance with Alpha Cabin (DIN EN ISO 354:2003). Furthermore, the sound absorber has a uniform appearance and excellent mechanical properties. It has a maximum transverse tensile strength of 62 N (according to DIN EN ISO 9073-2, 2022-05) and an internal strength of 1.28 N / 5 cm of the nonwoven fabric, measured according to DIN 54310 1980.

[0103] Example 2: The treated textile waste obtained in Example 1 is mixed with primary framework staple fibers and primary sheath-core binder fibers to obtain treated textile waste containing primary fibers. This treated textile waste has the same composition as the original textile waste of Example 1 in terms of the proportion of framework fibers and binder fibers (80 wt. % 1.7 dtex PET fibers (38 mm) and 20 wt. % 4.4 dtex PET / CoPET fibers), where the treated textile waste contains a) 25 wt. % and b) 50 wt. % reopened fibers.

[0104] The treated textile waste is then carded into a nonwoven fabric, which is then heat treated to a thickness of 250 g / m 2 The resulting sound absorbers, containing 25% and 50% by weight of reopened fibers, had a sound absorption strength of 160 Ns / m 3 and has the sound absorption coefficient shown in Figure 8. The sound absorbing material has a uniform appearance throughout and excellent mechanical properties.

Claims

1. 150 Ns / m measured according to DIN EN 29053, May 1993 edition ３ ~5000 Ns / m ３ and a flow resistance of 150 g / m ２ ~600g / m ２ A thermal bonded sound absorbing nonwoven fabric having a basis weight of a) comprising framework staple fibers having an average fineness of 0.9 dtex to 8.8 dtex in an amount of 50% by weight to 90% by weight based on the total weight of the nonwoven fabric; and b) A thermal bonded sound absorbing nonwoven fabric containing a core-sheath type binder fiber in an amount of 10% by weight to 50% by weight based on the total weight of the nonwoven fabric, 1. A thermally bonded acoustic nonwoven fabric, wherein the framework staple fibers comprise a proportion of chopped framework staple fibers, and the sheath-core binder fibers comprise a proportion of chopped sheath-core binder fibers.

2. 2. The thermally bonded sound absorbing nonwoven fabric of claim 1, wherein the nonwoven fabric comprises primary framework staple fibers, the primary framework staple fibers having an average fineness of 0.9 dtex to 8.8 dtex and / or an average staple length of 20 mm to 80 mm.

3. 3. The thermal-bonded sound-absorbing nonwoven fabric according to claim 1, wherein the nonwoven fabric comprises primary sheath-core binder fibers, the primary sheath-core binder fibers being staple fibers.

4. 2. The thermally bonded acoustic nonwoven fabric of claim 1, wherein the nonwoven fabric comprises primary framework staple fibers and / or primary sheath-core binder fibers, and the chopped sheath-core binder fibers have the same average fineness and / or the same polymer as the primary sheath-core binder fibers, and / or the chopped framework fibers have the same average fineness and / or the same polymer as the primary framework fibers.

5. 2. The thermal-bonded sound-absorbing nonwoven fabric according to claim 1, wherein the proportion of the chopped framework staple fibers to the total weight of the framework staple fibers is 10 to 100% by weight, and / or the proportion of the chopped sheath-core binder fibers to the total weight of the sheath-core binder fibers is 10 to 100% by weight.

6. The nonwoven fabric is a) 0% to 70% by weight of primary framework staple fibers; b) 0% to 70% by weight of primary sheath-core binder fibers; c) 5% to 90% by weight of chopped framework staple fibers; d) 1% to 50% by weight of crushed sheath-core binder fibers; 2. The thermally bonded sound absorbing nonwoven fabric of claim 1, comprising:

7. 2. The thermally bonded sound-absorbing nonwoven fabric of claim 1, wherein the nonwoven fabric is produced from textile waste that has been treated in a crushing process, and the crushing process is carried out so that the amount of undecomposed textile residue contained in the treated textile waste is less than 30% by weight of the total amount of the treated textile waste.

8. 150 Ns / m ３ ~5000 Ns / m ３ and a flow resistance of 150 g / m ２ ~600g / m ２ A method for producing a sound-absorbing nonwoven fabric having a basis weight of I. Providing textile waste, said textile waste comprising: a) comprising framework staple fibers having an average fineness of 0.9 dtex to 8.8 dtex in a proportion of 50% to 90% by weight based on the total weight of the textile waste; and b) a step of including a core-sheath binder fiber in an amount of 10% by weight to 50% by weight based on the total weight of the textile waste; II. At least partially disintegrating the textile structure of the textile waste in a crushing process to obtain a treated textile waste comprising a proportion of crushed framework staple fibers and a proportion of crushed sheath-core binder fibers; III. Forming a nonwoven fabric from the treated textile waste; IV. A step of heat-treating the nonwoven fabric to obtain a sound-absorbing nonwoven fabric. A method comprising:

9. 9. The method of claim 8, further comprising step I.2 of moistening the textile waste.

10. 10. A method according to claim 8 or 9, characterized in that the shredding process is carried out in a shredder, the operating principle of which is that the textile waste is fed to a shredding unit through an intake system which has a conveying and simultaneously a clamping action.

11. 9. The method of claim 8, wherein the textile waste is subjected to the shredding process multiple times.

12. 9. The method according to claim 8, characterized in that the disintegration of the textile structure of the textile waste in step II. is carried out to an extent that the treated textile waste contains at most 30% by weight of undisintegrated textile residues and / or the treated textile waste contains at least 70% by weight of textile single fibers relative to the total weight of the treated textile waste.

13. 9. The method of claim 8, further comprising blending the treated textile waste from step II. with primary framework staple fibers and / or primary sheath-core binder fibers.

14. 9. A method according to claim 8, characterized in that it produces a nonwoven fabric according to claim 1 or 2.

15. 3. Use of the sound-absorbing nonwoven fabric according to claim 1 or 2 for sound absorption in the automotive field.

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