Nonwoven laminate

Abstract

To provide nonwoven laminates that are suitable for molding applications.SOLUTION: There is provided a nonwoven laminate, consisting of, in order (A) to (C): a spunbond nonwoven layer (A) including fibers, which include polyethylene terephthalate (PET) and copolyester; an optional spunbond nonwoven layer (B) including fibers, which include polyethylene terephthalate (PET) and copolyester, wherein the nonwoven layer (B) has a higher copolyester content than nonwoven layer (A); and a needled staple fiber nonwoven layer (C), which includes monocomponent polyethylene terephthalate (PET) staple fibers (c1), and multicomponent staple fibers (c2), which include at least a polyethylene terephthalate (PET) component and a copolyester component, wherein all layers are melt-bonded to each other.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a nonwoven laminate and a molded article containing the nonwoven laminate. [Background technology]

[0002] By molding nonwoven laminates, molded articles for various applications can be obtained. Such articles are suitable for automotive applications where lightweight components with high stability and durability are required, such as underbody shields.

[0003] European Patent Application Publication No. 3769954 discloses a nonwoven laminate and a molded article manufactured therefrom that can be used as an underbody shield for automobiles. The nonwoven laminate comprises 3 to 5 layers of nonwoven fabrics that are fused together. Its structure is characterized by a needle-processed staple fiber nonwoven layer surrounded between two outer spunbond nonwoven layers. These layers are basically formed from polyethylene terephthalate (PET) fibers and copolyester fibers for fusion bonding. A molded article manufactured by molding such a nonwoven laminate has high mechanical stability and provides acoustic shielding.

[0004] U.S. Patent Application Publication No. 2016 / 0288451 discloses a nonwoven composite material that is moldable and can be used in the manufacture of a vehicle underbody. The nonwoven composite material comprises needle-processed polyester staple fiber layers and spunbond polyester fiber layers that are mechanically bonded to each other by needle processing.

[0005] U.S. Patent Application Publication No. 2018 / 0251924 relates to a nonwoven composite material that can be used in a variety of applications. This composite material is characterized by certain hydrophobic PET fibers and polyalkylsiloxane-based or perfluorinated additives.

[0006] However, there is still room for improvement in such nonwoven composite materials and the molded articles obtained therefrom. For use in the automotive industry, they must meet stringent internal standards regarding mechanical stability and durability. This ensures that the products are suitable for long-term use without degradation or loss of advantageous properties. Automotive structural components such as underbody shields, wheel arch liners, and engine shields are exposed to mechanical stress and strain over long periods. They must maintain their integrity and properties even after prolonged use under harsh conditions. Furthermore, vehicle structural components must also be resistant to stone chipping, which occurs continuously during standard use and causes high mechanical strain.

[0007] Problems that form the basis of inventions The object of the present invention is to provide a novel material that overcomes, at least partially, the drawbacks encountered in the art. It is desirable to provide an improved product suitable for structural components, particularly vehicle structural components. It is desirable that the product has high mechanical stability and is suitable for long-term use. Preferably, the material has good acoustic properties, recyclability, light weight, and low thermal shrinkage, and also exhibits a reduced elephant skin effect.

[0008] One specific challenge is to provide materials with high stone chipping resistance, such as nonwoven composites and molded articles. Therefore, it is desirable that these nonwoven composites and molded articles be very suitable for structural components in exterior applications such as underbody shields, wheel arch liners, and engine shields, where stone chipping is a problem.

[0009] A further challenge is that the material can be manufactured and molded in an easy and convenient manner. Ideally, the material should be available at low cost and through standard processing methods.

[0010] Disclosure of the invention Surprisingly, the problems underlying the present invention have been found to be solved by the nonwoven laminates and molded articles described in the claims. Further embodiments are outlined throughout this specification.

[0011] The subject of the present invention is a nonwoven laminate, the nonwoven laminate being (A) to (C): - Spunbond nonwoven layer (A) containing polyethylene terephthalate (PET) and copolyester fibers; - A nonwoven nonwoven layer (B) of any kind containing polyethylene terephthalate (PET) and copolyester fibers, wherein the nonwoven layer (B) has a higher copolyester content than the nonwoven layer (A); - Needle-processed staple fiber nonwoven layer (C), the following: • Single-component polyethylene terephthalate (PET) staple fiber (c1), and • Multicomponent staple fiber (c2), comprising at least a polyethylene terephthalate (PET) component and a copolyester component. Nonwoven layer (C) It is structured in the following order: Here, all layers are fused together to form a nonwoven laminate.

[0012] In this specification, the term "nonwoven" refers to a nonwoven fabric, which is a layer of fibers bound together by physical and / or chemical means other than weaving, knitting, or papermaking. In general, nonwoven fabrics are defined in DIN EN ISO 9092:2018.

[0013] Spunbond generally refers to a fabric containing theoretically infinite fibers drawn from molten fiber raw materials. The spunbond nonwoven layers (A) and (B) are preferably made of continuous filaments calendered together in sheet form. In all embodiments described herein, layer (B) is optional unless otherwise specified.

[0014] Staple fibers generally refer to fibers of varying lengths. A group of staple fibers has an average length of the fibers within the group, which is called the staple length.

[0015] A needle-punched nonwoven layer generally refers to a layer composed of a plurality of fibers entangled and bonded with needles.

[0016] Polyethylene terephthalate is a copolymer of terephthalic acid and ethane-1,2-diol (also called ethylene glycol).

[0017] A copolyester is a copolymer of a first diacid monomer, a first diol monomer, and one or both of at least one second different diacid monomer and at least one second different diol monomer. Here, the diacid monomer preferably refers to a dicarboxylic acid monomer.

[0018] Melt adhesion (thermal bonding) generally refers to a technique for joining high molecular weight, usually thermoplastic materials by applying heat such that at least one of the materials partially melts or softens, bringing these materials into close contact, and then cooling.

[0019] In the nonwoven laminate of the present invention, layers (A) and (C), and when present, intermediate layer (B) are also melt-bonded to each other. This can be achieved by forming a stack of the layers and melt-bonding this stack. By melt-bonding all the layers to each other, high uniformity of the heat shrinkage characteristics of the nonwoven laminate can be obtained. The high uniformity of the heat shrinkage characteristics can reduce the formation of elephant skin during molding. The reduction of the formation of elephant skin enables the nonwoven laminate to have an attractive aesthetic appearance and also to have higher bending strength after molding. Also, the melt-bonding between the layers can impart high dimensional stability to the nonwoven laminate during heating and molding.

[0020] Each layer contains polyethylene terephthalate. Polyethylene terephthalate is also referred to herein as "PET". The polyethylene terephthalate may be virgin polyethylene terephthalate (not recycled), recycled polyethylene terephthalate (also referred to as "r-PET"), or a mixture of virgin polyethylene terephthalate and recycled polyethylene terephthalate. Virgin polyethylene terephthalate can more precisely define the mechanical properties of the nonwoven laminate. Recycled polyethylene terephthalate can reduce the cost of the nonwoven laminate.

[0021] Polyethylene terephthalate can impart high uniformity to the mechanical properties of nonwoven laminates. This enhances the uniformity of elongation and tensile strength of the nonwoven laminates. As a result, the nonwoven laminates can be easily heated and molded to provide the desired configuration. Consequently, the nonwoven laminates can be dimensionally stable during heating and molding. Polyethylene terephthalate can provide relatively low basis weight for both the layers and the entire laminate.

[0022] Polyethylene terephthalate has a relatively high melting point of approximately 260°C. As a result, nonwoven laminates can have high heat resistance and non-flammability. In this specification, the melting point is preferably the melting point determined in accordance with DIN ISO 11357-3:2013.

[0023] The polyethylene terephthalate included in all layers is relatively inexpensive, which can help reduce the cost of articles containing nonwoven laminates.

[0024] Each layer contains a copolyester. The copolyester may be amorphous, crystalline, or a mixture of amorphous and crystalline copolyesters. If present, any layer (B) has a higher copolyester content than layer (A). The relatively high copolyester content of each layer can strengthen the bond between layer (A) and layer (C). Therefore, the relatively high copolyester content of each layer can increase the peel strength of layer (A).

[0025] The nonwoven laminate may consist of layers (A), (B), and (C), or more preferably, only layers (A) and (C).

[0026] Nonwoven laminates composed of layers (A) and (C) are preferred. Two-layer laminates are advantageous in terms of simplification of manufacturing and cost efficiency. No additional supply equipment for layer (B) is required for the manufacture of such laminates. Surprisingly, it has been found that nonwoven laminates composed of only layers (A) and (C) and / or molded articles obtained therefrom can meet the requirements of structural components for automotive applications.

[0027] Optionally, a layer (B) that functions as an adhesive layer can be included. Layer (B) can increase the bonding strength between outer layer (A) and outer layer (C). In such a laminate, delamination between layer (A) and layer (C) can be advantageously reduced. From the viewpoint of increasing delamination strength, a nonwoven laminate including layers (A), (B), and (C) may be preferred.

[0028] Preferably, none of layers (A), (B), and (C) are mechanically bonded to any other layer in the nonwoven laminate. It is particularly preferable that none of layers (A), (B), and (C) are needle-bonded to any other layer. In other words, there is no entanglement between any two of layers (A), (B), and (C). In particular, none of the fibers contained in the needle-bonded staple fiber nonwoven layer (C) extend into either layer (A) or (B). More preferably, none of the fibers of the needle-bonded staple fiber nonwoven layer (C) penetrate either layer (A) or (B). The absence of mechanical bonding minimizes the formation of undesirable elephant skin during heating, thereby achieving an attractive aesthetic. Furthermore, molded articles produced from nonwoven laminates without mechanical bonding are advantageously flat and, in particular, free from wrinkles, wavy structures, etc. Moreover, their bending strength can be increased.

[0029] The needle-processed staple fiber nonwoven layer (C) is preferably heat-shrunk before being combined with layer (A). Preferably, the needle-processed fibers shrink both longitudinally and transversely when exposed to heat. The heat-shrinkable layer (C) helps to avoid undesirable further shrinkage. This helps to avoid the formation of undesirable elephant skin in subsequent molding processes.

[0030] It is preferable that less than 20%, more preferably less than 10%, of all fibers contained in the nonwoven laminate are neither PET nor copolyester. Most preferably, all fibers contained in the nonwoven laminate are composed of PET, copolyester, or a mixture thereof. When all fibers contained in the nonwoven laminate are mainly, preferably exclusively, composed of PET, copolyester, or a mixture thereof, the nonwoven laminate can be relatively low-cost, relatively lightweight, and have relatively high peel strength.

[0031] The nonwoven laminate is preferably free of polyolefins, particularly polypropylene. This allows for easier recycling of the nonwoven laminate. This improves the heat resistance and non-flammability of the nonwoven laminate. It also improves the uniformity of the mechanical properties of the nonwoven laminate, particularly its elongation and tensile strength. This makes it easier to adjust the properties of products containing the nonwoven laminate.

[0032] The nonwoven laminate is preferably silicon and / or fluorine-free. Therefore, the nonwoven laminate is free of silicon compounds and / or fluorine compounds. It has been found that favorable properties can be achieved without additives such as polyalkylsiloxanes and perfluorinated compounds found in the composite material described in U.S. Patent Application Publication No. 2018 / 0251924. This is advantageous for convenient processing, low cost, and recycling.

[0033] The nonwoven laminate preferably does not contain inorganic reinforcing materials, particularly glass fibers. By omitting inorganic reinforcing materials, particularly glass fibers, processability can be improved. Furthermore, by omitting inorganic reinforcing materials, particularly glass fibers, the cost of articles containing the nonwoven laminate can be reduced.

[0034] It is preferable that the nonwoven laminate does not contain a lofting agent. By omitting the lofting agent, the dimensional stability of the nonwoven laminate during heating and molding can be improved. Furthermore, by omitting the lofting agent, the cost of articles containing the nonwoven laminate can be reduced.

[0035] Surprisingly, a nonwoven laminate composed of only two layers (A) and (C), and the molded articles obtained therefrom, proved suitable for structural components in automotive applications. Both mechanical stability and sound absorption can meet the standard tests for automotive parts specified for original equipment manufacturers (OEMs). Such standards are used in the technical field for parts and equipment provided for use by other manufacturers.

[0036] Preferably, all layers of the copolyester are polyethylene terephthalate copolymers. The polyethylene terephthalate copolymer comprises monomers terephthalic acid, ethane-1,2-diol, and at least one further different dicarboxylic acid monomer and / or at least one further different diol monomer. A preferred further dicarboxylic acid monomer is adipic acid. Another preferred further dicarboxylic acid monomer is isophthalic acid. A preferred further diol monomer is cyclohexanedimethanol. Polyethylene terephthalate copolymers can facilitate the recyclability of nonwoven laminates. Polyethylene terephthalate copolymers can increase the peel strength within nonwoven laminates. Polyethylene terephthalate copolymers can reduce the raw material costs of nonwoven laminates.

[0037] It is preferable that all layers of the copolyester have a melting point of ≤240°C. It is even more preferable that the copolyester has a melting point of ≤220°C, more preferably ≤210°C, even more preferably ≤200°C, even more preferably ≤190°C, and particularly preferably =180°C. The copolyester having a melting point of ≤240°C can reduce the energy required for melt bonding between layers. The copolyester having a melting point of ≤240°C can reduce the energy required for manufacturing the spunbond layers (A) and (B). This energy reduction can increase continuously as the melting points decrease to ≤220°C, ≤210°C, ≤200°C, ≤190°C, and =180°C, respectively.

[0038] The copolyester of layer (A) preferably has a melting point higher than that of the copolyester of layer (C), more preferably ≥20°C higher, even more preferably ≥30°C higher, and even more preferably ≥35°C higher. This makes it possible to achieve stronger bonding between the layers of the nonwoven laminate after melt bonding.

[0039] It is particularly preferable that layer (B) is absent, in which case the copolyester of layer (A) preferably has a melting point of 205 to 240°C, more preferably 210 to 230°C, and even more preferably 210 to 225°C. In this case, the copolyester of layer (C) preferably has a melting point of 160 to 200°C, more preferably 170 to 190°C, and even more preferably 175 to 185°C. This makes it possible to avoid delamination between layer (A) and layer (C).

[0040] It is preferable that all layers of the copolyester have a melting point of ≥100°C. It is even more preferable that the copolyester has a melting point of ≥110°C, more preferably ≥140°C, and still more preferably ≥160°C. Using a copolyester with a melting point of ≥100°C can increase the bond strength between layers after melt bonding.

[0041] It is preferable that all layers of copolyester have a melting point in the range of 100 to 240°C, more preferably 110 to 240°C, even more preferably 140 to 230°C, and still more preferably 160 to 225°C. Copolyesters having melting points within these ranges can reduce the energy required for melt bonding between layers, reduce the energy required for manufacturing the spunbond layers (A) and (B), and increase the bond strength between layers after melt bonding.

[0042] The copolyester of layers (A) and (B), and especially layer (A), is basically neutral, i.e., preferably has a pH value of 6.5 to 7.5, more preferably 6.8 to 7.2, and even more preferably 7.0. This makes it possible to avoid undesirable chemical interactions between the surface of the nonwoven laminate and the environment.

[0043] The copolyester in layers (A) and (B), and especially in layer (A), is 1.1-1.6 g / cm³. 3 , more preferably 1.2 to 1.5 g / cm³ 3 More preferably 1.3 to 1.4 g / cm³ 3It is preferable that the density is such that the laminate has appropriate strength while avoiding excessive costs.

[0044] It is more preferable that all layers of the copolyester are polyethylene terephthalate copolymers, and that these copolymers simultaneously have a melting point of ≤240°C. This can simultaneously lead to improved peel strength, reduced costs, and reduced energy required for melt bonding of each layer and for manufacturing the spunbond layer.

[0045] If layer (B) is present, it is preferable that layer (A) contains 2% to 30% copolyester, more preferably 5% to 25% copolyester. If layer (B) is absent, it is preferable that layer (A) contains at least 30% copolyester, more preferably 30 to 70% copolyester, particularly preferably at least 40% copolyester, at least 50% copolyester, at least 60% copolyester, or at least 70% copolyester. Such copolyester content can avoid a corrugated structure in the laminate. Such copolyester content can further improve the bending strength of the laminate. Here, % means weight % unless otherwise specified.

[0046] If layer (B) is present and layer (A) contains 2% to 30% copolyester, it may be easier to melt-bond layer (A) to layer (B) or layer (C). If layer (A) contains 2% to 30% copolyester, the peel strength of layer (A) can be increased. If layer (A) contains 5% to 25% copolyester, the ease of melt-bonding and the peel strength of layer (A) can be further increased.

[0047] If layer (A) contains at least 30%, more preferably at least 40%, at least 50%, at least 60%, or at least 70% copolyester, the peel strength can be increased by the absence of layer (B). This simplifies the manufacturing of the laminate. When layer (B) is preferably absent, it is particularly preferable that the copolyester of layer (A) has a melting point of 205-240°C, more preferably 210-230°C, and even more preferably 210-225°C. In this case, the copolyester of layer (C) preferably has a melting point of 160-200°C, more preferably 170-190°C, and even more preferably 175-185°C. This particularly helps to avoid delamination between layer (A) and layer (C).

[0048] The needle-processed staple fiber nonwoven layer (C) is preferably composed of 10-90% single-component staple fibers (c1) and 10-90% multi-component staple fibers (c2). More preferably, the layer (C) is composed of 20-80% single-component staple fibers (c1) and 20-80% multi-component staple fibers (c2), more preferably 30-70% single-component staple fibers (c1) and 30-70% multi-component staple fibers (c2), even more preferably 40-60% single-component staple fibers (c1) and 40-60% multi-component staple fibers (c2), and most preferably 50% single-component staple fibers (c1) and 50% multi-component staple fibers (c2). When layer (C) consists of 10-90% single-component staple fibers (c1) and 10-90% multi-component staple fibers (c2), it can be more easily manufactured as a needle-processed layer. When layer (C) consists of 10-90% single-component staple fibers (c1) and 10-90% multi-component staple fibers (c2), it is mainly composed of polyethylene terephthalate. This allows for a reduction in the weight of the nonwoven laminate, an improvement in the heat resistance and non-flammability of the nonwoven laminate, and a reduction in the cost of the nonwoven laminate. These effects increase as the ratio of (c1) / (c2) approaches 1, meaning that these effects increase in the following order: 20-80%(c1) / 20-80%(c2), 30-70%(c1) / 30-70%(c2), 40-60%(c1) / 40-60%(c2), and 50%(c1) / 50%(c2).

[0049] Staple fiber (c1) is a single-component fiber, i.e., composed of polyethylene terephthalate. Staple fiber (c2) is a multi-component fiber, i.e., composed of two or more components. The first component of staple fiber (c2) is polyethylene terephthalate. The second component of staple fiber (c2) is copolyester. One or more additional components may be present in staple fiber (c2). Preferably, staple fiber (c2) is a two-component fiber, i.e., composed of polyethylene terephthalate and copolyester. The two-component fiber preferably has a sea-island filament structure, a pi-segment filament structure, a core-sheath filament structure, or a side-by-side filament structure, more preferably a core-sheath filament structure. The copolyester component generally exists on the surface of such a two-component fiber.

[0050] The staple fiber (c2) preferably has at least one, more preferably two or more, and most preferably all of the following properties: - Fineness of 1 to 10 dtex, more preferably 3 to 6 dtex, and even more preferably 4 to 6 dtex, measured in accordance with DIN EN ISO 1973:2020-05; - Fiber length of 30-100 mm, more preferably 40-60 mm, and even more preferably 45-55 mm; - Strength of 1-6 g / de, more preferably 2-5 g / de, and even more preferably 3-4 g / de, as measured in accordance with DIN EN 13844:2003-04; - Elongation of 20-60%, more preferably 30-50%, and even more preferably 35-55%, as measured in accordance with DIN EN ISO 5079:2020-01; - A crimp count of 4 to 10 EA / inch, more preferably 5 to 9 EA / inch, and even more preferably 6 to 8 EA / inch, measured in accordance with JIS L-1074; - A heat shrinkage rate at 75 °C for 15 minutes of 3 to 7%, more preferably 4 to 6%, still more preferably 3.5 to 4.5%, measured in accordance with DIN EN 13844:2003-04; and - A melting point of 160 to 200 °C, more preferably 170 to 190 °C, still more preferably 175 to 185 °C.

[0051] When the staple fiber (c2) has at least one of the above characteristics, more preferably two or more, and most preferably all, the needle-processed staple fiber nonwoven layer (C) can impart strength, flexibility and formability to the nonwoven laminate simultaneously.

[0052] Layer (C) has a basis weight of ≤ 2900 g / m 2 , more preferably 400 to 2500 g / m 2 according to DIN EN 29073-1:1992-08. In the application of a standard passenger car, layer (C) has a basis weight of 600 to 1500 g / m 2 , more preferably 700 to 1200 g / m 2 , most preferably 800 to 1000 g / m 2 is preferred.

[0053] Layer (C) is composed of 10 to 90% single-component staple fiber (c1) and 10 to 90% multi-component staple fiber (c2), and at the same time, has a basis weight of ≤ 2900 g / m 2 , more preferably 600 to 1500 g / m 2 according to DIN EN 29073-1:1992-08. In this way, the nonwoven layer (C) can be manufactured more easily as a needle-processed layer, and the nonwoven laminate can be widely used especially as vehicle structural parts.

[0054] The spunbond nonwoven layer (A) has a basis weight of 20 to 200 g / m 2 , more preferably 30 to 80 g / m 2It is preferable that the material has a basis weight. The inclusion of such a relatively lightweight spunbond layer can be particularly advantageous in terms of overall properties.

[0055] The entire nonwoven laminate has a density of 650-1600 g / m² according to DIN EN 29073-1:1992-08. 2 Preferably, the base weight is such that the nonwoven laminate has a thickness of 2 to 8 mm.

[0056] If an additional spunbond layer (B) is included, it is preferable that the fibers of the nonwoven layer (B) be composed of copolyester, because in that case it becomes easier to fuse all the layers together. The spunbond nonwoven layer (B) can increase the peel strength of layer (A). The spunbond nonwoven layer (B) is 1 to 100 g / m² according to DIN EN 29073-1:1992-08. 2 Preferably 5-50 g / m 2 , comfortably 10-20g / m 2 It is preferable that the laminate has a certain basis weight. This makes it possible to achieve a good balance between the lightweight nature of the laminate and the high wear resistance of the laminate.

[0057] In a preferred embodiment, the laminate is - Does not contain spunbond nonwoven layer (B), - The copolyesters of layers (A) and (C) are copolymers of polyethylene terephthalate, and the copolymer has a melting point of 100 to 240°C; and - The needle-processed staple fiber nonwoven layer (C) consists of 40-60% single-component staple fibers (c1) and 40-60% multi-component staple fibers (c2).

[0058] Such a suitable nonwoven laminate can be easily heated and molded to provide the desired configuration. Such a nonwoven laminate can be dimensionally stable during heating and molding. Such a nonwoven laminate is particularly suitable for structural components, especially structural components for exterior applications, preferably structural components for vehicles. The absence of layer (B) can reduce costs and simplify manufacturing.

[0059] Further embodiments - The copolyesters of layers (A), (B), and (C) are copolymers of polyethylene terephthalate, and the copolymer has a melting point of 100 to 240°C; - The spunbond nonwoven layer (B) is composed of copolyester and has a density of 10-20 g / m² according to DIN EN 29073-1:1992-08. 2 Having a basis for; and - The needle-processed staple fiber nonwoven layer (C) consists of 40-60% single-component staple fibers (c1) and 40-60% multi-component staple fibers (c2).

[0060] Such nonwoven laminates can be easily heated and molded to provide the desired configuration. Such nonwoven laminates can be dimensionally stable during heating and molding. Such nonwoven laminates are suitable for structural components, particularly vehicle structural components. The presence of layer (B) can increase peel strength and heat resistance.

[0061] The subject matter of the present invention is also a molded article comprising the nonwoven laminate of the present invention. The molded article can be obtained by molding the nonwoven laminate in a mold. Typically, molding is carried out under heat and / or pressure. During or after molding, the nonwoven laminate is bonded. Typically, density increases, porosity decreases, while mechanical stability improves. The molded article can be molded into a predetermined form and shape. Generally, the molded article is rigid and can be cut. Overall, a mechanically stable and relatively lightweight article can be obtained, which is suitable for automotive applications such as underbody shields. Preferably, the molded article has the shape of a desired automotive part, such as an underbody shield.

[0062] In a preferred embodiment, the molded article is obtained by cold forming. In the cold forming process, the nonwoven laminate is preferably preheated for 1 to 5 minutes at a temperature range of 180°C to 220°C, depending on the basis weight. This is intended to activate the low-melting-point copolyester, which acts as a binder. The activation of the binder causes it to melt, forming a kind of adhesive between it and the virgin PET fibers or recycled PET fibers. This also acts as an adhesive between the staple 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 to a tonnage of 50 to 200 tons. The nonwoven laminate is left in the mold for a maximum of 60 seconds. The compressed nonwoven laminate is allowed to cool inside or outside the mold, allowing the staple fiber and spunbond copolyester fibers to cool below their melting points. The nonwoven laminate is then converted into its final shape. For example, the final thickness of the material can be 2mm to 6mm depending on the requirements of the intended application. The nonwoven laminate is then trimmed as needed, which can be achieved by mechanical cutting, thermal cutting, or waterjet cutting.

[0063] The molded articles of the present invention benefit from the advantages of the nonwoven laminates described herein. Particularly noteworthy are the reduced formation of elephant skin during molding and the related advantages.

[0064] The molded article and / or nonwoven laminate preferably have at least one of the following characteristics: - Bending strength of ≥330 MPa according to ISO 178:2019-04; - Tensile strength of ≥780N according to ASTM 5034:2009; and / or - Tear strength of ≥110N according to DIN EN 29073-3:1992-08.

[0065] A bending strength of ≥330 MPa, a tensile strength of ≥780 N, and / or a tear strength of ≥110 N can result in high abrasion resistance of the nonwoven laminate. A bending strength of ≥330 MPa, a tensile strength of ≥780 N, and / or a tear strength of ≥110 N can also enhance the sound absorption properties of the nonwoven laminate.

[0066] It is more preferable that the nonwoven laminate has a flexural strength of ≥370 MPa, more preferably ≥400 MPa, and even more preferably ≥430 MPa. It is more preferable that the nonwoven laminate has a tensile strength of ≥850 N, more preferably ≥900 N, and even more preferably ≥950 N. It is more preferable that the nonwoven laminate has a tear strength of ≥125 N, more preferably ≥145 N, and even more preferably ≥165 N. The flexural strength, tear strength, and tensile strength can be adapted by adjusting parameters such as the thickness of the layer, the type of fiber, the amount of binder copolymer, and the bonding method. This can further improve the mechanical properties of the nonwoven laminate, such as stone chipping resistance and sound absorption.

[0067] Nonwoven laminates and molded articles can be used in the automotive industry and, by extension, in vehicles, but also in all means of transport, namely land, sea, or aerospace applications, such as aircraft, ships, or railway components. Nonwoven laminates and molded articles are particularly suitable for structural components that require high stability, especially structural components for vehicles.

[0068] Nonwoven laminates or molded articles are particularly well-suited for exterior applications, preferably for vehicle applications. Preferred exterior applications are those subjected to high stress and strain, such as underbody shields, wheel arch liners, and engine shields. Use in exterior applications benefits from the advantages of the nonwoven laminates and / or molded articles described herein. Particularly noteworthy are the effects of improved mechanical stability, stone chipping resistance and abrasion resistance, high heat resistance, non-flammability and sound absorption, and related advantages. Preferably, in exterior applications, the molded article is positioned so that layer (C) faces outward. Since layer (C) is a surface layer, it is exposed to the outside. Therefore, the molded article is positioned so that layer (A) faces inward.

[0069] The subject matter of the present invention is also a structural component, preferably for a vehicle, preferably for exterior use, which includes molded articles of the present invention. Exterior components are preferably underbody shields, wheel arch liners, or engine shields. The subject matter of the present invention is also a interior component, preferably for a vehicle, which includes molded articles of the present invention. Interior components are preferably panels, casings, coverings, reinforcements, or sheet materials. Interior components are preferably for doors, roofs, trunks, or seats. The subject matter of the present invention is also a vehicle, which includes molded articles and / or structural components of the present invention.

[0070] In further embodiments, nonwoven laminates and molded articles can be used for interior applications, particularly for vehicle interiors. Preferred interior applications include, for example, panels, casings, coverings, reinforcements, or plates for doors, roofs, trunks, or seats. Use in interior applications benefits from the advantages of the nonwoven laminates and / or molded articles described herein.

[0071] The nonwoven laminate of the present invention is as follows: - A process for manufacturing a needle-processed staple fiber nonwoven layer (C) by needle processing, - A step of providing layers (A), optionally (B) and (C) in this order, - A process of melting and bonding these layers together. It can be manufactured by a method that includes [the specified method].

[0072] The method for manufacturing nonwoven laminates benefits from the advantages of nonwoven laminates. Particularly noteworthy is the effect of easy joining of each layer by melt bonding, which can lead to improved peel strength and related advantages.

[0073] In a preferred embodiment, layer (c) can be manufactured as outlined below. Prior to the needle processing step, the fibers (c1) and (c2) are opened from the bale, mixed, and carded. Subsequently, the fibers (c1) and (c2) are cross-wrapped and passed through a needleing machine. Another fiber preparation method is performed by the air-laid method, in which the opened fibers are collected on a suction band and needle-processed. The needle-processed nonwoven fabric can be pre-shrunk by applying heat to avoid shrinkage in the subsequent molding process. The staple fibers (c1) and / or (c2) preferably have a staple length in the range of 10 mm to 150 mm, more preferably 40 mm to 100 mm.

[0074] In one embodiment, layer (C) comprises a mixture of 10-70% virgin or recycled PET staple fibers (c1) and 30-90% binary fibers (c2). The binary fibers have a core-sheath structure in which the sheath has a lower melting point than the core. The binary fibers preferably take on various geometric configurations such as a side-by-side structure, a core-sheath structure, a segment pie structure, or a sea-island structure.

[0075] In one embodiment, the binder polymer of the two-component fiber (c2) 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 having a melting point of <200°C. One particularly preferred binder fiber has a core-sheath filament configuration. The core is composed of PET having a melting point of >250°C, i.e., about 260°C, and the sheath comprises a copolyester having a lower melting point in the range of 100°C to 200°C.

[0076] In one embodiment, layer (C) is pre-shrunk to avoid further shrinkage in subsequent molding processes. Pre-shrinkage is performed after the needleing process. Needled staple fibers are processed by passing them through an oven typically set to a temperature above the melting point of the low-melting-point copolymer. For example, in the case of a two-component fiber having a sheath polymer with a melting point of 180°C, the oven temperature can be set to a temperature above 180°C.

[0077] In one embodiment, layer (A) is 30-150 g / m² 2 A coarse denier spunbond nonwoven fabric can be used. Spunbond is a PET-based filament having a circular structure containing 1-50% copolyester. The copolyester melts during the molding process and aids in bonding with adjacent layers. Furthermore, the basis weight of layer (A) is significantly lower than that of layer (C). This may be desirable in situations where it is desirable to reduce the overall weight of the final part and lower costs.

[0078] Layer (B), when placed between layers (A) and (C), can be a copolyester-based spunbond nonwoven layer. This copolyester-based spunbond nonwoven layer is used to enhance the bonding between layers (A) and (C), i.e., it functions as an adhesive layer. The adhesive layer (B) contains a low-melting-point copolyester. Its weight is preferably 1 g / m². 2 ~50g / m 2 This is within the range. In this embodiment, layer (C) can be pre-shrunk to avoid shrinkage during the subsequent molding process.

[0079] The copolyester in all layers melts during molding, promoting bonding with adjacent layers. As a result, the fibers of the nonwoven laminate, particularly those containing copolyester, may partially or completely lose their fibrous structure in the laminate after melt bonding. The resulting structure is incorporated into the nonwoven laminate of the present invention. If the adhesive layer (B) is absent, the amount of copolyester in layer (A) is typically increased.

[0080] The entire laminate is formed by establishing fusion bonding, rather than mechanical bonding, between all layers. The laminate can then be molded into the desired shape for a specific application. The laminated structure is formed using either a cold forming or hot forming process.

[0081] Preferably, the multicomponent fiber is a two-component fiber. A pi-segment filament structure is particularly useful for multicomponent filaments. The multicomponent filament is a multicomponent staple fiber (c2) and may be present in a spunbond nonwoven layer (A) and / or (B). Preferably, the multicomponent filament has eight segments alternating from PET segments and copolyester segments. Alternatively, the multicomponent filament may have a filament structure containing 16, 32, or 64 segments alternating from PET segments and copolyester segments. During the molding process, the low-melting-point copolyester melts, providing rigidity to the material.

[0082] Sheath-core filament structures can be useful for spunbond nonwoven layers (A) and / or (B) as well as multi-component staple fibers (c2). A two-component filament structure can consist of a sheath of a low-melting-point copolymer and a core of PET having a higher melting point. During the molding process, the low-melting-point copolyester melts, imparting rigidity to the material.

[0083] Side-by-side filament structures can be useful for spunbond nonwoven layers (A) and / or (B) as well as multi-component staple fibers (c2). 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, providing rigidity to the material.

[0084] Preferably, the single-component fibers of the nonwoven laminate, particularly the single-component staple fibers of layer (C), are conventional fibers, preferably having a round or substantially round cross-section. Such fiber morphology can be obtained by spinning fibers from simple circular or elliptical orifices. Preferably, the nonwoven laminate does not contain single-component fibers having unusual shapes, such as hollow fibers. Favorable properties have been found to be obtained with standard fibers, which is advantageous in terms of cost and manufacture.

[0085] The molded articles and nonwoven laminates solve the problems underlying the present invention. These products possess high mechanical stability, good acoustic properties, recyclability, lightweight properties, and low thermal shrinkage, and exhibit reduced elephant skin effect. Furthermore, the material has high stone chipping resistance. Therefore, nonwoven composites and molded articles are highly suitable for structural components and / or exterior applications, particularly for vehicle applications such as underbody shields, wheel arch liners, and engine shields. The materials are available at low cost and can be manufactured and molded in convenient and easy ways.

[0086] Examples Example 1 - Manufacturing of a two-layer nonwoven laminate The following materials were used in the manufacture of the nonwoven laminate: Staple fiber (For layer (C)): 50% single-component staple fiber (c1): Material: r-PET Staple length: 64mm Fineness: 6.7dtex Weight: 800-1000g / m 2 50% two-component staple fiber (c2): Composition: core-sheath type Materials: Sheath: PET, Core: Copolyester with a melting point of 180°C Staple length: 51mm Fineness: 5dtex.

[0087] Spunbond (For layer (A)): Material: 90% PET; 10% PET copolyester (CoPET) Weight: 50g / m 2 Thickness: 0.33~0.59mm Filament diameter: 25-60 μm.

[0088] Staple fibers were mixed in a 50:50 weight ratio. Next, the staple fibers were carded, cross-wrapped, and needled. The needles used were Groz-Beckert 36gg fine needles, and the total needled strength was 350 needles / cm². 2 The needlework depth was set to 10 mm on both sides. The needleworked material was then passed through a ventilated oven heated to 200°C at a rate of 10°C / min. This heating of the needleworked material activated the two-component fibers, causing the material to harden when it came out of the oven. Layer (C) was thus produced. Layer (C) was then passed through a pair of calender rolls, into which layer (A) was introduced. The calender pressure was set to 25 bar on both sides at a temperature of 200°C, thereby producing a nonwoven laminate in which layers (A) and (C) were fused together. These layers are not mechanically bonded to each other. The produced two-layer laminate was then cut into sheets.

[0089] Example 2 - Manufacturing of molded articles The sheet-cut material from Example 1 was placed in an oven heated to 210°C for 3 minutes (for a ventilated oven) or 1 minute (for an infrared oven). The material softened due to the heat. The material was then immediately transferred to a cold press where it was molded under high pressure (50 tons or more). The nonwoven laminate was left in the mold for a maximum of 60 seconds. The compressed nonwoven laminate was cooled in or out of the mold so that the staple fibers and spunbond copolyester fibers were cooled below their melting points. The nonwoven laminate was then transformed into its final shape.

[0090] Example 3 - Acoustic Characteristics The acoustic properties of a sample of the molded article from Example 2 were tested. The test sample was placed against the wall or bottom of the alpha cabin with a 2 mm air gap. Next, the absorption coefficient of the sample was measured by a series of sensors inside the cabin. The results of the alpha cabin test for a sample with a molding thickness of 5 mm are shown in Table 1 below.

[0091] [Table 1]

[0092] Sound absorption coefficient α s The higher the value, the better the acoustic performance of the test sample. This result indicates that molded articles obtained from a two-layer nonwoven laminate have high sound absorption properties. The tested wavelength range is particularly relevant to automotive underbody shields, where it is necessary to shield the interior of a vehicle from noise from the underside of the vehicle.

[0093] Furthermore, comparative examples showed that the sound absorption efficiency of the molded article obtained from the corresponding three-layer nonwoven laminate having an additional spunbond layer on the surface opposite to layer (C) was almost the same as that of the molded article according to European Patent Application Publication No. 3769954.

[0094] Example 4 - Mechanical properties The bending strength of molded articles obtained from a two-layer nonwoven laminate was measured. For comparison, the bending strength of molded articles obtained from a corresponding three-layer nonwoven laminate according to European Patent Application Publication No. 3769954 (see Example 3) was also measured.

[0095] Under the following test conditions, the pressure required to bend the material by 2 mm was measured: Starting pressure: 0.5N Speed: 10mm / min Distance between sample holders: 64 mm Press element radius: 5mm.

[0096] [Table 2]

[0097] As can be seen from Table 2, molded articles obtained from two-layer nonwoven laminates have high flexural strength. The flexural strength of molded articles obtained from two-layer laminates meets the requirements for underbody shields in automotive applications. The flexural strength is only slightly lower than that of the comparative three-layer laminate.

[0098] Example 5 - Stone chipping resistance The stone chipping resistance of molded articles obtained from a two-layer laminate and molded articles obtained from the comparative three-layer laminate described in the above examples was investigated using tests based on DIN EN ISO 20567-1:2017. This standard is provided for testing paints and varnishes, but is also applicable to testing molded articles. Therefore, this test is used in the automotive sector as an OEM standard for simulating stone chipping on the surface of automotive parts such as underbody shields. In this test method, a predetermined amount of abrasive grains of a predetermined size is sprayed onto the probe surface under specific harsh conditions. Performance is evaluated using standardized comparative images. Before each chipping test, a new chipping material is used to determine the amount. The test is performed in 1 kg steps from 0 kg to 8 kg, with 0 kg being the initial position. According to the OEM standard, the material passes the test if the surface fringing is less than 4 mm after the entire series of abrasive grains from 0 kg to 8 kg has been applied to the surface. Fringing refers to the appearance of loose threads protruding from the surface of the test piece. Nine test specimens were tested in this analysis. A stone chip tester (VDA, Model 508, Erichsen) was used, and the tests were conducted under the following conditions: - Pressure: 2.0 bar (200 kPa) - Angle: 30° - Material: High-grade gravel, particle size 5-8mm - Material amount: 1~8kg - Test specimen size: 100mm x 100mm - Test field: 80mm x 80mm - Test time: 10 seconds per 500g.

[0099] A molded article of the present invention obtained from a two-layer laminate was arranged such that stone chipping occurred on the surface corresponding to layer (C). A comparative molded article obtained from a three-layer laminate includes two identical surfaces of the spunbond nonwoven layer.

[0100] The comparative molded article failed the test. While no holes were observed in the test specimen, fringing was present in the range of 4–8 mm, and therefore excessively hard. Visual inspection after stone chipping revealed a significant amount of fibers and fiber bundles protruding from the surface of the test specimen. Thus, the fibrous surface disintegrated during stone chipping.

[0101] In molded articles obtained from the two-layer material, no holes were observed in the material after stone chipping. Furthermore, the level of fringing was low, clearly below the standard value of 4 mm. Therefore, the material of the present invention passed the standardized stone chipping test. Visual inspection revealed that the surface was relatively flat, with no fibers or fiber bundles protruding from the surface.

[0102] These results demonstrate that the two-layer material exhibits significantly superior resistance to stone chipping tests compared to the comparative three-layer material. The material of the present invention is suitable for exterior applications such as automotive underbody shields, wheel arch liners, and engine shields.

Claims

1. The use of molded articles containing nonwoven laminates as structural components for vehicles, The aforementioned structural component is an underbody shield, a wheel arch liner, or an engine shield. The aforementioned nonwoven laminates are (A) to (C): - Spunbond nonwoven layer (A) containing polyethylene terephthalate (PET) and copolyester fibers; - A nonwoven layer (B) of any kind containing polyethylene terephthalate (PET) and copolyester fibers, wherein the nonwoven layer (B) has a higher copolyester content than the nonwoven layer (A); - Needle-processed staple fiber nonwoven layer (C), the following: - Single-component polyethylene terephthalate (PET) staple fiber (c1), and - Multicomponent staple fiber (c2), comprising at least a polyethylene terephthalate (PET) component and a copolyester component. Nonwoven layer (C) including It consists of (A) to (C), Here, all layers are melt-bonded to each other, and layers (A), (B), and (C) are not needle-processed to each other. The molded article is arranged such that layer (C) is exposed to the outside. The aforementioned use.

2. The use according to claim 1, wherein layers (A), (B), and (C) are not mechanically bonded to each other.

3. The use according to claim 1 or 2, wherein the needle-processed staple fiber nonwoven layer (C) is heat-shrunk.

4. The use according to claim 1 or 2, wherein the nonwoven laminate does not contain polyolefin.

5. The use according to claim 1 or 2, wherein all layers of the copolyester are a copolymer of polyethylene terephthalate, and the copolymer has a melting point of ≤240°C as measured in accordance with DIN ISO 11357-3:2013.

6. The use according to claim 1 or 2, wherein layer (A) contains 10% to 70% copolyester.

7. The use according to claim 1 or 2, wherein the needle-processed staple fiber nonwoven layer (C) is composed of 10-90% single-component staple fibers (c1) and 10-90% multi-component staple fibers (c2).

8. The needle-processed staple fiber nonwoven layer (C) is measured in accordance with DIN EN 29073-1:1992-08 and has a density of 600 to 1500 g / m². ２ Having a basis weight of 20 to 200 g / m² as measured in accordance with DIN EN 29073-1:1992-08, and / or the spunbond nonwoven layer (A) having a basis weight of 20 to 200 g / m² as measured in accordance with DIN EN 29073-1:1992-08. ２ The use according to claim 1 or 2, having the basis weight.

9. - The nonwoven laminate consists of layers (A) and (C), - The copolyester of layers (A) and (C) is a copolymer of polyethylene terephthalate, and the copolymer has a melting point of 100 to 240°C; and - The use according to claim 1 or 2, wherein the needle-processed staple fiber nonwoven layer (C) is composed of 40-60% single-component staple fibers (c1) and 40-60% multi-component staple fibers (c2).

10. The use according to claim 1 or 2, wherein the molded article is obtained by cold forming or hot forming the nonwoven laminate.

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