Spunbond nonwoven fabric

Abstract

A spunbonded nonwoven fabric includes a hollow polymeric multi-component fiber. The spunbonded nonwoven fabric has a thickness of at least 1 mm. The thickness of the spunbonded non-woven fabric is measured according to DIN EN ISO 9073-2: 1997-02. The spunbonded non-woven fabric can be used as a non-woven fabric. The thickness of the spun-bonded nonwoven fabric according to DIN EN ISO 9073-2: 1997-02 may be in the range of from 1 mm to 25 mm.

Description

Technical Field

[0001] This invention relates to spunbond nonwoven fabrics, methods for preparing the same, nonwoven laminates comprising the spunbond nonwoven fabrics, and molded articles comprising such nonwoven laminates. Background Technology

[0002] Molded articles for a variety of applications can be obtained by molding nonwoven laminates. Such articles are suitable for automotive, marine, aerospace, geotextile, and rail vehicle applications where lightweight parts requiring high stability and durability are needed, such as base plates for vehicles.

[0003] EP 3 769 954 A1 discloses a nonwoven laminate and a molded article produced therefrom, the molded article being used as a base guard plate for a vehicle. The nonwoven laminate comprises three to five layers of nonwoven fabric fused together. The structure is characterized by a needle-punched short-fiber nonwoven layer enclosed between two outer spunbond nonwoven layers. This layer is essentially formed of polyethylene terephthalate (PET) fibers and copolyester fibers for fusion bonding. The molded article produced by molding such a nonwoven laminate exhibits high mechanical stability and acoustic shielding properties.

[0004] US 2016 / 0288451 A1 discloses a moldable nonwoven composite material that can be used to produce vehicle bases. The nonwoven composite material comprises a needle-punched short polyester fiber layer and a spunbond polyester fiber layer, which are mechanically bonded to each other by needle punching.

[0005] US 2018 / 0251924 A1 relates to a nonwoven composite material that can be used for a variety of applications. The composite material is characterized by comprising specific hydrophobic PET fibers and polyalkylsiloxane-based additives or perfluorinated additives.

[0006] However, known nonwoven composite materials and the molded products derived from them can still be improved. When used in the automotive industry, stringent internal standards must be met regarding mechanical stability and durability. This ensures that the product is suitable for long-term use without performance degradation or loss. Automotive structural components (such as underbody panels, wheel arch liners, or engine hoods) are exposed to mechanical stress and strain over extended periods. They should maintain their integrity and properties even under harsh conditions. Vehicle structural components must also be resistant to gravel, as gravel continuously occurs during normal use, leading to high mechanical strain. Summary of the Invention

[0007] In one embodiment, this disclosure provides a spunbond nonwoven fabric comprising hollow polymer multicomponent fibers, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is at least 1 mm. Attached Figure Description

[0008] The subject matter of this disclosure will now be described in more detail with reference to the exemplary accompanying drawings. All features described and / or shown herein can be used alone or in different combinations. The features and advantages of various embodiments will become apparent from the following detailed description with reference to the accompanying drawings, which illustrate the following: Figure 1 A comparison of sound absorption properties between needle-punched short fiber fabrics and hollow bicomponent spunbond fabrics is presented (DIN ISO10534-1). Detailed Implementation

[0009] In its implementation, the present invention provides a novel material that at least partially overcomes the drawbacks encountered in the art. The present invention aims to provide improved products suitable for structural components, particularly those for vehicles. These products should possess high mechanical stability, be lightweight, and be suitable for long-term use. Preferably, the material should also possess good acoustic properties and be recyclable.

[0010] Low weight is particularly desirable in molded products. Needle-punched staple fibers are indeed more bulky, thus allowing for lighter molded products. However, their disadvantage is that they do not possess the same good mechanical properties as spunbond fibers. Furthermore, the manufacturing process for needle-punched staple fibers is lengthy, resulting in high costs. On the other hand, spunbond fibers have good mechanical properties but are not bulky and have a smooth fiber surface.

[0011] Therefore, it is desirable to provide a nonwoven fabric that is bulky and thus imparts lightweight properties to the molded article without sacrificing good mechanical properties.

[0012] It would be advantageous if the material could be produced and shaped in a simple and convenient manner. The material should be inexpensive and obtainable through standard processing methods.

[0013] Surprisingly, the aforementioned advantages have been found to be achievable through spunbond nonwoven fabrics and molding articles according to embodiments of the present invention.

[0014] Embodiments of the present invention provide a spunbond nonwoven fabric comprising hollow polymer multicomponent fibers, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is at least 1 mm. In a preferred embodiment, the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is in the range of 1 mm to 25 mm, preferably 2 mm to 16 mm, and particularly 4 mm to 10 mm.

[0015] Embodiments of the present invention further provide a method for preparing spunbond nonwoven fabrics as defined herein, wherein hollow multicomponent fibers are employed, the hollow multicomponent fibers comprising at least one hollow polymer fiber as defined above and below, preferably wherein the spunbond nonwoven fabric is prepared by melt spinning or solution spinning of the hollow multicomponent fibers through a spinneret including an orifice pattern, wherein a polymer melt is passed through a spinneret having a hollow portion to form a single fiber, particularly wherein the fibers exiting the spinneret are subjected to a one-step drafting process.

[0016] An embodiment of the present invention further provides a nonwoven laminate comprising layers arranged in the order (A), (B), (A): A spunbond nonwoven fabric layer (A) comprising hollow polymer multicomponent fibers, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is at least 1 mm. Adhesive layer (B); - An additional spunbond nonwoven fabric layer (A), which comprises hollow polymer multicomponent fibers, preferably bicomponent fibers, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is at least 1 mm.

[0017] Layer A used in nonwoven laminates can be the same or different. However, in all cases, the general definition of a nonwoven fabric is met.

[0018] Embodiments of the present invention further provide a molding article comprising a spunbond nonwoven fabric as defined above and below or a laminate as defined above and below.

[0019] Embodiments of the present invention further provide a structural component for a vehicle, the structural component comprising a molded article as defined above and below, wherein the structural component is preferably a base guard plate, wheel arch lining, or engine hood.

[0020] Embodiments of the present invention further provide a vehicle comprising molded articles and / or structural components as defined above and below.

[0021] Embodiments of the present invention further provide applications of molded articles as defined above and below in the automotive, marine, aerospace and rail vehicle sectors, particularly as structural components of vehicles, wherein the structural components are preferably base guards, wheel arch liners or engine hoods.

[0022] Spunbond nonwoven fabrics: Embodiments of the present invention provide a spunbond nonwoven fabric comprising hollow polymer multicomponent fibers, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is preferably 1 mm to 25 mm, more preferably 2 mm to 16 mm, and particularly 4 mm to 8 mm.

[0023] As used herein, the term nonwoven refers to nonwoven fabrics. This is a layer of fibers that are bonded together by physical and / or chemical means, excluding weaving, knitting, or papermaking. Generally, nonwoven fabrics are defined by DIN EN ISO 9092:2018.

[0024] Spunbond generally refers to a fabric containing theoretically endless fibers drawn from molten fiber raw material. Preferably, the spunbond nonwoven layer (A) is made of continuous filaments calendered together in sheet form.

[0025] Multicomponent fibers contain at least two (e.g., 2, 3, 4, 5 or more) different polymer components. Preferred are multicomponent fibers composed of two polymer components (bicomponent fibers). Suitable types of bicomponent fibers are sheath / core fibers (also known as core / shell fibers), side-by-side fibers, island-in-the-sea fibers, and pie-piece fibers.

[0026] In an embodiment, the multicomponent fiber is composed of at least two different polymers, wherein the melting point of one polymer is preferably at least 10°C higher than the melting point of the second polymer also present in the fiber, more preferably at least 20°C higher.

[0027] In another embodiment, the multicomponent fiber includes or is composed of core / sheath type fibers, wherein the core material has a higher melting point and the sheath material has a lower melting point.

[0028] The preferred bicomponent fiber contains two polymer components selected from two different polyesters. Particularly preferred are the two different polyesters selected from polyethylene terephthalate (PET), copolyethylene terephthalate (Co-PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), copolybutylene terephthalate (Co-PBT), polylactic acid (PLA), poly(ethylene succinate) (PES), poly(butylene succinate) (PBS), poly(ethylene adipate) (PEA), and poly(butylene succinate-co-adipate). Butylene glycol ester (PBSA), polyhydroxyacetic acid (PGA), poly(butylene succinate-co-butylene sebacate) (PBsu-co-BSe), poly(butylene succinate-co-butylene adipate) (PBSu-co-bad), poly(tetramethylene succinate) (PTMS), polycaprolactone (PCL), polypropiolactone (PPL), poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and mixtures thereof.

[0029] Specifically, the bicomponent fiber contains two polymer components selected from polyethylene terephthalate, co-polyethylene terephthalate (Co-PET), polyethylene naphthalate, and polybutylene terephthalate.

[0030] In one embodiment, the bicomponent fiber comprises polyethylene terephthalate (PET) and copolyethylene terephthalate (Co-PET) or is composed of PET / Co-PET.

[0031] In this application, the term "Co-PET" refers to a copolymer of terephthalic acid, 1,2-ethylene glycol (ethylene glycol), and at least one additional monomer. The additional monomer is preferably selected from dicarboxylic acid monomers other than terephthalic acid; diol monomers other than 1,2-ethylene glycol; monomers comprising at least one carboxylic acid and at least one hydroxyl group, wherein the hydroxyl group is polymerizable with the carboxylic acid group; and other monomers and mixtures thereof. Suitable additional acid monomers are aromatic, aliphatic, and alicyclic dicarboxylic acids. Suitable additional aromatic dicarboxylic acid monomers are 2,6-naphthalenedicarboxylic acid and isophthalic acid. Suitable additional aliphatic or alicyclic dicarboxylic acids are adipic acid, azelaic acid, sebacic acid, dodecanoic acid, cyclohexanedicarboxylic acid, and mixtures thereof.

[0032] Suitable alternative diol monomers to 1,2-ethylenediol are 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanediol, neopentyl glycol, and mixtures thereof.

[0033] Therefore, the term "Co-PBT" refers to a copolymer of terephthalic acid, 1,4-butanediol, and at least one other monomer. Suitable other diol monomers other than 1,2-ethylenediol are 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanediol, neopentyl glycol, and mixtures thereof.

[0034] Copolymers of terephthalic acid, 1,2-ethylene glycol, and 1,4-butanediol can be designated as Co-PET or Co-PBT, depending on the higher content of the diol.

[0035] Polyesters, particularly polyalkylene terephthalates (such as polyethylene terephthalate and copolyethylene terephthalate), can be prepared by methods known to those skilled in the art, for example by reacting an aromatic dicarboxylic acid or its C1-C4 alkyl ester or other ester-forming derivative (such as a halide or anhydride) with an aliphatic dihydroxy compound.

[0036] Preferably, the core-forming fibers and the shell-forming fibers in the bicomponent fiber are different materials. Specifically, the core-forming fibers contain or are composed of PET, while the shell-forming fibers contain or are composed of Co-PET. Specifically, the PET:Co-PET ratio is in the range of 90:10 to 40:60.

[0037] Polyethylene terephthalate (PET) is a copolymer of phthalic acid and 1,2-ethylene glycol (also known as ethylene glycol). PET is also referred to herein as "PET". PET can be virgin PET (which is not recycled), recycled PET (also known as "r-PET"), or a mixture of virgin and recycled PET. Virgin PET allows for more precise setting of the mechanical properties of nonwoven laminates. Recycled PET allows for reduced costs of nonwoven laminates.

[0038] Polyethylene terephthalate (PET) can impart a high degree of uniformity to the mechanical properties of nonwoven fabrics. Therefore, the uniformity of elongation and tensile strength in nonwoven fabrics can be improved. Nonwoven fabrics are thus easily heated and shaped to provide the desired structure. Consequently, nonwoven fabrics can be dimensionally stable when heated and shaped. PET can provide relatively low basis weights for each layer and the entire laminate.

[0039] Polyethylene terephthalate (PET) has a relatively high melting point, approximately 260°C. Therefore, nonwoven fabrics made from it can possess high heat resistance and non-flammability. The melting point described herein is preferably the one determined according to DIN ISO 11357-3:2013.

[0040] The nonwoven fabric preferably comprises at least one copolyester in the form of a multicomponent fiber. The copolyester is a copolymer of a first dicarboxylic acid monomer and a first diol monomer, and at least one additional comonomer selected from at least one different second dicarboxylic acid monomer, at least one different second diol monomer, and a different comonomer thereof. Suitable copolyester forming monomers are those mentioned for multicomponent fibers, which are incorporated herein by reference.

[0041] Nonwoven fabrics may also contain at least one polyester fiber different from polyethylene terephthalate. Suitable polyester forming monomers and polyesters are those mentioned for multicomponent fibers. Specifically, the polyester is selected from polyethylene naphthalate, polybutylene terephthalate, and mixtures thereof.

[0042] The nonwoven fabric may also contain at least one additional copolyester fiber different from the multicomponent fibers described above. The additional fiber comprises or is composed of a copolyester of a first dicarboxylic acid monomer and a first diol monomer, and at least one additional comonomer selected from at least one different second dicarboxylic acid monomer, at least one different second diol monomer, and a different comonomer thereof. Suitable copolyester forming monomers are those mentioned for the multicomponent fibers and are incorporated herein by reference.

[0043] Other suitable multicomponent fibers are selected from at least two polymers, at least one of which is a polyolefin, particularly a polypropylene homopolymer or copolymer. A particular embodiment is a bicomponent fiber comprising PP and Co-PP. The monomers are ethylene and 1,2-butene.

[0044] The copolyester can be an amorphous copolyester, a crystalline copolyester, or a mixture of at least one amorphous copolyester and at least one crystalline copolyester.

[0045] Preferably, the copolyester is a copolymer of polyethylene terephthalate (PET). The PET copolymer comprises terephthalic acid monomer, 1,2-ethylene glycol, and at least one other different dicarboxylic acid monomer and / or at least one other different glycol monomer. A preferred additional dicarboxylic acid monomer is adipic acid. Another preferred additional dicarboxylic acid monomer is isophthalic acid. A preferred additional glycol monomer is cyclohexanediol. PET copolymers facilitate the recyclability of nonwoven fabrics. PET copolymers can increase the peel strength within nonwoven fabrics. PET copolymers can reduce the cost of raw materials for nonwoven fabrics.

[0046] Preferably, the copolyester has a melting point ≤240°C. More preferably, the copolyester has a melting point ≤220°C, further preferably ≤210°C, even more preferably ≤200°C, and still more preferably ≤190°C, particularly ≤180°C. A copolyester with a melting point ≤240°C reduces the energy required to melt and bond the layers together. A copolyester with a melting point ≤240°C reduces the energy required to produce the spunbond layers (A) and (C) as defined below. The energy reduction can continue to increase as lower melting points of ≤220°C, ≤210°C, ≤200°C, ≤190°C, and ≤180°C are reached, respectively.

[0047] Preferably, the copolyesters in layers (A), (B), and (C) are substantially neutral, i.e., with a pH of 6.5 to 7.5, more preferably 6.8 to 7.2, and still more preferably 7.0. This avoids undesirable chemical interactions between the surface of the nonwoven fabric and the environment.

[0048] Preferably, the copolyester has a density of 1.1 g / cm³. 3 Up to 1.6 g / cm 3 More preferably 1.2 g / cm 3 Up to 1.5 g / cm 3 And even more preferably 1.3 g / cm 3 Up to 1.4 g / cm 3 The density is determined according to DIN EN ISO 1183-1:2019-09. This density produces nonwoven fabrics with appropriate strength while avoiding excessive costs.

[0049] More preferably, the copolyester is a copolymer of polyethylene terephthalate, and the copolymer has a melting point ≤240°C. This can simultaneously improve peel strength, reduce costs, and decrease the energy required to melt-bond the layers and produce the spunbond layer.

[0050] Preferably, the binder polymer in the multicomponent fiber is selected based on its melting point. In a preferred core-sheath configuration, the core is preferably composed of PET, and the sheath is preferably composed of a copolyester with a melting point < 200°C. A particularly preferred binder fiber has a core-sheath filament configuration. The core is composed of PET with a melting point > 250°C, i.e., about 260°C, and the sheath comprises a copolyester having a lower melting point in the range between 100°C and 200°C.

[0051] Preferably, the multicomponent fiber is a bicomponent fiber. Segmented filament structures are particularly useful for multicomponent filaments. Multicomponent filaments are multicomponent short fibers and can be present in spunbond nonwoven fabrics. Preferably, the multicomponent filament has eight segments consisting of alternating PET and copolyester segments. It can be constructed using filaments with alternating 16, 32, or 64 PET and copolyester segments. During the molding process, the low-melting-point copolyester melts and provides rigidity to the material.

[0052] Core-sheath filament structures can be used in spunbond nonwoven fabrics as well as multicomponent staple fibers. Bicomponent filament structures can consist of a sheath of a low-melting-point copolymer and a core of PET with a higher melting point. During the molding process, the low-melting-point copolyester melts and imparts rigidity to the material.

[0053] Side-by-side filament structures can be used in spunbond nonwoven fabrics as well as multicomponent staple fibers. The side-by-side filament structure consists of a low-melting-point copolymer on one side and PET with a higher melting point on the other. During the molding process, the low-melting-point copolyester melts and provides rigidity to the material.

[0054] Based on the total cross-sectional area of ​​the fiber, the hollow fraction of the fiber's cross-sectional area ranges from 2% to 25%. The total cross-sectional area of ​​the fiber is the sum of the hollow cross-sectional area and the remaining fiber cross-sectional area.

[0055] Preferably, the hollow rate of the cross-sectional area of ​​the fiber is in the range of 4% to 25% based on the total cross-sectional area of ​​the fiber; specifically, the hollow rate of the cross-sectional area of ​​the multi-component fiber is in the range of 6% to 12% based on the total cross-sectional area of ​​the fiber.

[0056] In the implementation, the hollow shape can be circular, elliptical, triangular, quadrilateral, square, T-shaped, M-shaped, S-shaped, Y-shaped, or H-shaped.

[0057] In another embodiment, the hollow part has a circular shape.

[0058] In a preferred embodiment, the fiber has only one pore.

[0059] The spunbond nonwoven fabric according to an embodiment of the present invention is preferably thermoforming. Thermoforming is a manufacturing process in which a nonwoven fabric is heated to a flexible forming temperature, formed into a specific shape in a mold, and trimmed to produce a usable product.

[0060] As measured according to DIN EN 29073-1:1992-08, the basis weight (also known as mass per unit area) of the spunbond nonwoven fabric according to an embodiment of the present invention is preferably 200 g / m². 2 Up to 600 g / m 2 .

[0061] As determined according to DIN EN 29073-1:1992-08, the basis weight (also known as mass per unit area) of the spunbond nonwoven laminate according to an embodiment of the present invention, based on the total weight of all layers of spunbond nonwoven fabric, is preferably 400 g / m². 2 Up to 2000 g / m 2 .

[0062] According to embodiments of the invention, the sound absorption coefficient of the spunbond nonwoven fabric, measured according to DIN ISO 10534-1 (2001) at a wall spacing of 10 mm and a frequency of 1600 to 2500 Hz, particularly at 2000 Hz, is preferably greater than 40%.

[0063] In the implementation of spunbond nonwoven fabrics, 100 g / m 2 The thermal insulation of the fabric, as measured according to DIN52612 1979-09, is at least 0.39 W / mK.

[0064] Process: Hollow multicomponent fibers according to embodiments of the present invention are prepared by melt spinning or solution spinning through spinneret orifices. For melt spinning, molten polymer can be fed to the spinneret, for example, via an extruder. Preferably, a single fiber is formed from a spinneret having a hollow portion. Specifically, the core is surrounded by PET, and the outer core is surrounded by low-melting-point PET (which is CoPET). Thus, a single fiber is formed from the combined plasticized polymer melt exiting through the spinneret. In other words, the shape of the fiber is formed by slots.

[0065] Preferably, in the process of an embodiment of the invention, the fibers leaving the spinneret undergo a one-step drawing process (stretching process). For the drawing process, for example, the newly formed fibers leaving the spinneret orifice are first passed through a heating zone, where a temperature is set to induce plastic deformation of the fibers. Following the heating zone may be a cooling zone. In the cooling zone, the temperature of the fibers is reduced below their glass transition temperature Tg. Cooling can be performed in various ways known to those skilled in the art. When the fiber bundle leaves the cooling zone, the temperature of the fiber bundle should be low enough that it can pass through or along a rotating or static guide element without permanently deforming the fibers or bundle. For drawing, the speed (spinning speed) at which the fibers leave the spinneret orifice and through the heating and cooling zones (if any) is constant. The speed can be set to a specific value, for example, by passing the fiber bundle through one or more guide rollers multiple times. If necessary, the guide rollers can be heated. Through stretching and / or drawing, the fibers acquire their final mechanical properties and morphology, particularly their fineness.

[0066] In the one-step drafting process according to an embodiment of the present invention, the fiber (i.e., the initial spun product) is drafted immediately after the spinning speed is fixed.

[0067] In a preferred embodiment of the process of the present invention, the fibers exiting the spinneret are aerodynamically stretched to obtain the desired strength. The filaments obtained during spinning can be deposited to form a nonwoven fabric. For example, the filaments obtained during spinning are deposited on a deposition belt, where the filaments are stacked on top of each other.

[0068] In another preferred embodiment of the process of the present invention, the spinning process can be carried out in the form of a melt-blowing process, wherein the melt leaving the spinneret is entrained by an airflow under high pressure and high temperature, thereby forming fine fibers. These fibers can also be deposited to form nonwoven fabrics. This is mainly done on a deposition drum.

[0069] Nonwoven laminates: In one embodiment, the present invention further provides a nonwoven laminate comprising layers arranged in the order (A), (B), (A): - A spunbond nonwoven fabric layer (A), the spunbond nonwoven fabric layer comprising hollow polymer multicomponent fibers, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is at least 1 mm, preferably 1 mm to 25 mm, more preferably 4 mm to 10 mm. Adhesive layer (B); - An additional spunbond nonwoven fabric layer (A), which comprises hollow polymer multicomponent fibers, preferably bicomponent fibers, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO 9073-2:1997-02 is at least 1 mm, preferably 1 mm to 25 mm, more preferably 4 mm to 10 mm.

[0070] Melt bonding (thermal bonding) generally refers to a technique for joining polymer (usually thermoplastic) materials by applying heat, causing at least one material to partially melt or soften, thereby bringing the materials into close contact, and then cooling.

[0071] In nonwoven laminates, layer (A) and intermediate / adhesive layer (B) are preferably fused together, and particularly preferably, layers (A) and (B) are not mechanically bonded together. This can be achieved by forming a layer stack and fused together the stack. The fused bonding of all layers together results in highly uniform thermal shrinkage properties in the nonwoven laminate. This high uniformity of thermal shrinkage properties reduces wrinkle formation during molding. Due to the reduction in wrinkle formation, the nonwoven laminate can have an attractive aesthetic and higher flexural strength after molding. The fused bonding of the layers together during heating and forming also imparts high dimensional stability to the nonwoven laminate.

[0072] Layer (A) contains polyethylene terephthalate (PET) as defined above.

[0073] The adhesive layer (B) preferably comprises or consists of CoPET, PP, CoPP, CoPBT or the like, and specifically, the polymer in the adhesive layer (B) has a melting point ≤20°C.

[0074] Nonwoven laminates can consist of layers (A) and (B). Nonwoven laminates can be further arranged in the following order: A, B, A, B, A, B, A, B, A, B, A, B 、 A comprises at least one additional spunbond nonwoven fabric layer (A), at least one additional adhesive layer (B), preferably 1, 2, 3, 4, 5, 6, 7, 8 additional nonwoven fabric layers (A), preferably 1, 2, 3, 4, 5, 6, 7, 8, particularly 1, 2, 3, 4, 5 additional nonwoven fabric layers (A), and particularly 1, 2, 3, 4, 5 additional adhesive layers (B).

[0075] Preferably, the nonwoven laminate does not contain inorganic reinforcing materials, especially glass fibers. The absence of inorganic reinforcing materials, particularly glass fibers, simplifies processability.

[0076] Preferably, the nonwoven laminate contains no bulking agents. The absence of bulking agents makes the nonwoven laminate sustainable. The absence of bulking agents can reduce the cost of articles including nonwoven laminates.

[0077] Preferably, the basis weight of the spunbond nonwoven layer (A) is 300 g / m², as determined according to DIN EN 29073-1:1992-08. 2 Up to 2000 g / m 2 For applications in standard passenger vehicles, it is preferred that the basis weight of layer (A) is 600 g / m³. 2 Up to 1500 g / m 2 More preferably 700 g / m 2 Up to 1200 g / m 2 And most preferably 800 g / m 2 Up to 1000 g / m 2 .

[0078] Preferably, the basis weight of the spunbond nonwoven layer (B) according to DIN EN 29073-1:1992-08 is 20 g / m². 2 Up to 200 g / m 2 More preferably 30 g / m 2 Up to 80 g / m 2 The overall properties may be particularly advantageous when such a relatively lightweight spunbond layer is included.

[0079] Preferably, the basis weight of the entire nonwoven laminate, according to DIN EN 29073-1:1992-08, is 300 g / m². 2 Up to 2000 g / m 2 Preferably, the thickness of the nonwoven laminate is 2 mm to 10 mm.

[0080] These nonwoven laminates can be easily heated and shaped to provide a desired configuration. When heated and shaped, they can be dimensionally stable. They are suitable for structural components, especially for vehicles. Due to the presence of the layer (B), peel strength and heat resistance can be high.

[0081] Embodiments of the present invention provide a molded article comprising a nonwoven laminate according to embodiments of the invention. The molded article can be obtained by molding the nonwoven laminate into a certain form (“mold”). Typically, molding is performed under heat and / or pressure. After or during molding, the nonwoven laminate is consolidated. Typically, density increases and porosity decreases, while mechanical stability increases. The molded article can be molded into a defined form and shape. It is typically rigid, allowing it to be cut. Overall, a mechanically stable and relatively lightweight article is obtained, suitable for automotive applications such as underbody panels. Preferably, the molded article has the shape of a desired automotive part, such as an underbody panel.

[0082] In a preferred embodiment, the molded article is obtained by cold molding. In the cold molding process, the nonwoven laminate is preferably preheated for 1 to 5 minutes at a temperature ranging from 180°C to 220°C, depending on the basis weight. This is to activate the low-melting-point copolyester that acts as a binder. By activating the binder, it melts and forms an adhesive between the virgin or recycled PET fibers. It also acts as an adhesive between the short-fiber nonwoven layer and the spunbond nonwoven layer. After activation, the nonwoven laminate is placed in a compression mold. The compression mold can then compress all or part of the nonwoven laminate at a tonnage of 50 to 200 tons. The nonwoven laminate is allowed to remain in the mold for up to 60 seconds. The compressed nonwoven laminate is allowed to cool inside or outside the mold to cool the short-fiber and copolyester fibers in the spunbond structure below their melting points. Thereafter, the nonwoven laminate is transformed into its final shape. For example, the final thickness of the material can be between 2 mm and 6 mm, depending on the requirements of the intended application. The nonwoven laminate is then trimmed as needed, which can be done by mechanical cutting, thermal cutting, or waterjet cutting.

[0083] In its implementation, the present invention provides a molded article that benefits from the advantages of the nonwoven laminates described herein. Particularly noticeable are the effects of reducing wrinkle formation during molding and the associated advantages.

[0084] Preferably, the molded article and / or nonwoven laminate has at least one of the following characteristics: According to ISO 178:2019-04, the flexural strength is ≥250 MPa; According to ASTM 5034:2009, tensile strength ≥ 500 N; and / or Tear strength ≥100 N according to DIN EN 29073-3:1992-08.

[0085] More preferably, the flexural strength of the nonwoven laminate is ≥250 MPa, even more preferably ≥300 MPa, and still more preferably ≥400 MPa. More preferably, the tensile strength of the nonwoven laminate is ≥500 N, even more preferably ≥7500 N, and still more preferably ≥950 N. More preferably, the tear strength of the nonwoven laminate is ≥100 N, even more preferably ≥125 N, and still more preferably ≥140 N. The flexural strength, tear strength, and tensile strength can be adapted by adjusting parameters such as layer thickness, fiber type, amount of binder copolymer, and consolidation method. Therefore, the mechanical properties of the nonwoven laminate, such as stone impact resistance and material stability, can be further improved.

[0086] Nonwoven laminates and molded parts can be used in the automotive industry and therefore in vehicles, as well as in general transportation applications, such as aircraft, ships, or railway parts. They are particularly suitable for structural components, especially in vehicles requiring high stability.

[0087] Nonwoven laminates or molded parts are particularly suitable for external applications, preferably for vehicles. Preferred external applications are especially those subjected to high stress and strain, such as base plates, wheel arch liners, or engine hoods. Use in external applications benefits from the advantages of the nonwoven laminates and / or molded parts described herein. Particularly noteworthy are the enhanced mechanical stability, resistance to gravel and abrasion, high heat resistance, flame retardancy, and sound absorption, and the advantages that come with them.

[0088] Embodiments of the present invention provide a structural component, preferably for external applications, comprising a molded article of an embodiment of the present invention, preferably for a vehicle. The external component is preferably a base guard, wheel arch liner, or engine hood. Embodiments of the present invention also provide an interior product, comprising a molded article of an embodiment of the present invention, preferably for a vehicle. The interior product is preferably a panel, shell, cladding, reinforcing material, or sheet metal. The interior product is preferably used for doors, roofs, trunks, or seats. Embodiments of the present invention also provide a vehicle, comprising molded articles and / or structural components of an embodiment of the present invention.

[0089] In another embodiment, nonwoven laminates and molded articles can be used for interior applications, particularly for vehicles. Preferred interior applications are panels, shells, cladding, reinforcing materials, or sheet metal, such as for doors, roofs, trunks, or seats. Use for interior applications benefits from the advantages of the nonwoven laminates and / or molded articles described herein.

[0090] Nonwoven laminates can be produced by the following method, the method comprising: Preparation of spunbond nonwoven fabric / layer (A); Provide spunbond nonwoven fabrics / layers (A), (B), and (A) in sequence; and The layers are fused and bonded together.

[0091] The methods used to produce nonwoven laminates benefit from the advantages of nonwoven laminates. Particularly noticeable are the effects of easily bonding the layers via melt bonding (which improves peel strength) and the associated advantages.

[0092] The entire laminate is formed by establishing a fusion bond (rather than a mechanical bond) between all layers. The laminate is then placed under conditions for molding into the shape required for a specific application. The layered structure is molded using either a cold molding process or a hot molding process.

[0093] An embodiment of the present invention further provides a molding article comprising a spunbond nonwoven fabric nonwoven according to an embodiment of the present invention or a laminate according to an embodiment of the present invention.

[0094] Preferably, the molded article is obtained by cold molding or hot molding of the spunbond nonwoven fabric or the nonwoven laminate according to embodiments of the present invention. Cold molding or hot molding processes are known to those skilled in the art, and IR molding is a hot molding process.

[0095] Embodiments of the present invention further provide a structural component for a vehicle, the structural component comprising a molded article as defined above, wherein the structural component is, for example, a base guard plate, wheel arch lining, engine hood, switchgear unit, transformer (especially a distribution transformer or power transformer), rotating electric machine, generator, electric motor, driver, semiconductor assembly, power electronic device, converter station.

[0096] Embodiments of the present invention further provide a vehicle comprising molded articles and / or structural components as defined above.

[0097] Embodiments of the present invention further provide the use of the molded article according to an embodiment of the present invention as a structural component for a vehicle, wherein the structural component is preferably a base guard plate, wheel arch lining or engine hood.

[0098] Molded parts and nonwoven laminates address the problems underlying conventional solutions. These products offer high mechanical stability and good acoustic properties, are recyclable, lightweight, and exhibit low thermal shrinkage with reduced wrinkling effects. Furthermore, the materials possess high stone impact resistance. Therefore, nonwoven composites and molded parts are ideally suited for applications in the automotive, marine, aerospace, and rail vehicle sectors. Nonwoven composites and molded parts are particularly suitable for structural components and / or exterior applications, especially for vehicles such as base plates, wheel arch liners, or engine hoods. The materials are readily available at low cost and can be produced and molded using convenient and simple methods.

[0099] Example 1 The spunbond fabric comprises bicomponent fibers produced using a special spinneret, wherein the bicomponent fibers have a hollow portion in a core (=inner core), the core being encased in PET (=outer core), and the outer core being encased in a low-melting-point PET polymer, the low-melting-point PET polymer being Co-PET. The PET forming the outer core has a melting point of 255°C, and the Co-PET forming the shell has a melting point of 223°C. The PET:Co-PET ratio in the cross-section is 60:40, and the amount of the hollow portion in the core is 8%.

[0100] Table 1 shows a comparison of the mechanical properties of the spunbond fabric according to an embodiment of the present invention with those of a 100% needle-punched staple fiber fabric, wherein the spunbond fabric comprises hollow polymer multicomponent fibers and the needle-punched staple fiber fabric comprises 50 wt% PET (6.7 dTex, 67 mm) and 50 wt% PET:Co-PET (4.4 dTex, 51 mm).

[0101] Table 1 The results of Example 1 demonstrate that the bulky spunbond fabric comprising hollow polymer multicomponent fibers according to embodiments of the present invention exhibits significantly better mechanical properties than 100% needle-punched staple fiber fabrics. Although the staple fiber fabric has a higher content of Co-PET, its mechanical properties are inferior to those of the endless spunbond fabric according to embodiments of the present invention. The 8% hollow portion contributes more to achieving better thermal insulation than its comparative fabric.

[0102] Example 2: The spunbond fabric comprises bicomponent fibers produced using a special spinneret, wherein the bicomponent fibers have a hollow portion in a core (=inner core), the core being encapsulated by PET (=outer core), and the outer core being encapsulated by a low-melting-point PET polymer, namely Co-PET. The PET forming the outer core has a melting point of 223°C, and the CoPET has a melting point of 255°C. The PET:CoPET ratio in the cross-section is 80:20, and the amount of the hollow portion in the core is 6%.

[0103] Table 2 shows a comparison of the mechanical properties of the spunbond fabric according to an embodiment of the present invention with those of a 100% needle-punched staple fiber fabric, the spunbond fabric comprising hollow polymer multicomponent fibers, the needle-punched staple fiber fabric comprising 50% PET (6.7 dTex, 67 mm) and 50 wt.% PET:Co-PET (4.4 dTex, 51 mm), and the spunbond fabric comprising hollow polymer multicomponent fibers.

[0104] Table 2 The results of Example 2 demonstrate that the bulky spunbond hollow bicomponent fiber fabric according to an embodiment of the present invention exhibits significantly better mechanical properties than the 100% needle-punched staple fiber fabric. Although the staple fiber fabric contains a large amount of Co-PET, its mechanical properties are inferior to those of the endless spunbond hollow bicomponent fiber fabric. The 6% hollow portion contributes more to achieving better thermal insulation than its comparative counterpart.

[0105] Example 3: The spunbond fabric comprises bicomponent fibers produced using a special spinneret, wherein the bicomponent fibers have a hollow portion in a core (=inner core), the core being encased in PET (=outer core), and the outer core being encased in a low-melting-point PET polymer, the low-melting-point PET polymer being Co-PET. The PET forming the outer core has a melting point of 255°C, and the Co-PET forming the shell has a melting point of 223°C. The PET:Co-PET ratio in the cross-section is 60:40, and the amount of the hollow portion in the core is 8%.

[0106] Figure 1 A comparison of sound absorption properties between needle-punched short fiber fabrics and hollow bicomponent spunbond fabrics according to embodiments of the present invention is shown (DIN ISO 10534-1).

[0107] Acoustic profiles show that hollow bicomponent spunbond fabrics exhibit better absorption performance in the low and mid-frequency ranges than short-fiber fabrics. This is crucial for material selection in automotive applications.

[0108] While the subject matter of this disclosure has been shown and described in the accompanying drawings and the foregoing description, such illustrations and descriptions are to be considered illustrative or exemplary, and not restrictive. Any statements made herein characterizing the invention should also be considered illustrative or exemplary, and not restrictive, as the invention is defined by the claims. It should be understood that changes and modifications can be made by those skilled in the art within the scope of the following claims, which may include any combination of features from the different embodiments described above.

[0109] The terms used in the claims should be interpreted as having the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the articles “a” or “the” when introducing elements should not be interpreted as excluding multiple elements. Similarly, the expression “or” should be interpreted as inclusive, such that the expression “A or B” does not exclude “A and B” unless it is clear from the context or the foregoing description that only one of A and B is referred to. Furthermore, the statement “at least one of A, B, and C” should be interpreted as one or more elements of a set of elements consisting of A, B, and C, and should not be interpreted as requiring at least one element of each of the listed elements A, B, and C, regardless of whether A, B, and C are related as a category or otherwise. In addition, the expressions “A, B, and / or C” or “at least one of A, B, or C” should be interpreted as including any single entity of the listed elements (e.g., A), any subset of the listed elements (e.g., A and B), or the entire list of elements A, B, or C.

Claims

1. A spunbond nonwoven fabric comprising: Hollow polymer multicomponent fibers, The thickness of the spunbond nonwoven fabric, according to DIN EN ISO 9073-2:1997-02, is at least 1 mm.

2. The spunbond nonwoven fabric according to claim 1, wherein the thickness of the spunbond nonwoven fabric according to DIN EN ISO9073-2:1997-02 is in the range of 1 mm to 25 mm.

3. The spunbond nonwoven fabric according to claim 1, wherein the hollow polymer multicomponent fiber comprises hollow bicomponent fiber.

4. The spunbond nonwoven fabric according to claim 1, wherein the hollowness of the cross-sectional area of ​​the fibers, based on the total cross-sectional area of ​​the multi-component fibers, is in the range of 4% to 25%.

5. The spunbond nonwoven fabric according to claim 1, wherein the hollow polymer multicomponent fiber contains at least two polymer components selected from two different polyesters.

6. The spunbond nonwoven fabric according to claim 5, wherein the polyester is selected from polyethylene terephthalate (PET), copolyethylene terephthalate (Co-PET), polyethylene naphthalate, polybutylene terephthalate, copolybutylene terephthalate, polylactic acid, poly(ethylene succinate), poly(butylene succinate), poly(ethylene adipate), poly(butylene succinate-co-butylene adipate), polyglycolic acid, poly(butylene succinate-co-butylene sebacate), poly(butylene succinate-co-butylene adipate), poly(tetramethylene succinate), polycaprolactone, polypropionol, poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and mixtures thereof.

7. The spunbond nonwoven fabric according to claim 6, wherein the hollow polymer multicomponent fiber contains PET / Co-PET, and the PET:Co-PET ratio is in the range of 90:10 to 40:

60.

8. The spunbond nonwoven fabric according to claim 1, wherein the nonwoven fabric is thermoformable.

9. The spunbond nonwoven fabric according to claim 1, wherein the basis weight of the nonwoven fabric is 200 g / m², as determined according to DIN EN 29073-1:1992-08. 2 Up to 600 g / m 2 .

10. The spunbond nonwoven fabric according to claim 1, wherein the sound absorption coefficient of the spunbond nonwoven fabric, as measured according to DIN ISO 10534-1 at a wall spacing of 10 mm and a frequency of 1600 to 2500 Hz, is greater than 40%.

11. The spunbond nonwoven fabric according to claim 1, wherein 100 g / m 2 The thermal insulation of the fabric, as measured according to DIN 52612-1979-09, is at least 0.39 W / mK.

12. A method for preparing a spunbond nonwoven fabric according to claim 1, wherein hollow multicomponent fibers are used, the method comprising: The spunbond nonwoven fabric is prepared by passing the hollow multicomponent fibers through a spinneret with an orifice pattern via melt spinning or solution spinning. The polymer melt is passed through a spinneret with a hollow section to form single fibers, and The fibers leaving the spinneret are subjected to a one-step drawing process.

13. A nonwoven laminate comprising: Layers arranged in the order of (A), (B), (A), Layer (A) is a spunbond nonwoven fabric layer comprising hollow polymer multicomponent fibers, the thickness of which, according to DIN EN ISO 9073-2:1997-02, is at least 1 mm, and Layer (B) is the adhesive layer.

14. The nonwoven laminate of claim 13, wherein layers (A) and (B) are fused together.

15. The nonwoven laminate of claim 13, wherein the adhesive layer comprises Co-PET, PP, Co-PP, Co-PBT, and the polymer in the adhesive layer has a melting point below 240°C.

16. The nonwoven laminate according to claim 13, wherein the basis weight of the nonwoven laminate is 300 g / m², as measured according to DIN EN 29073-1:1992-08. 2 Up to 2000 g / m 2 .

17. The nonwoven laminate of claim 13, wherein the laminate further comprises at least one additional spunbond nonwoven fabric layer and at least one additional adhesive layer.

18. A molding article comprising the spunbond nonwoven fabric according to claim 1.

19. A structural component for a vehicle, the structural component comprising the molded article according to claim 18.

20. A vehicle comprising the molded article according to claim 18.

21. The molding article of claim 18, wherein the molding article is configured for arrangement in an automobile, marine vehicle, aerospace vehicle or rail vehicle.

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