Spunbond nonwoven fabric

Abstract

Spunbond nonwoven fabrics contain hollow polymer multi-component fibers. Spunbond nonwoven fabrics have a thickness of at least 1 mm. The thickness of spunbond nonwoven fabrics conforms to DIN EN ISO 9073-2:1997-02. Spunbond nonwoven fabrics may have a thickness in the range of 1 to 25 mm, conforming to DIN 9073-2 / 1997.

Description

[Technical Field]

[0001] The present invention relates to spunbond nonwoven fabrics, methods for preparing the same, nonwoven laminates containing spunbond nonwoven fabrics, and molded articles containing such nonwoven laminates.

[0002] Background technology Molded articles for various applications can be obtained by molding nonwoven laminates. Such articles are suitable for automotive, marine, aerospace, geotextile, and railway vehicle applications, where lightweight components with high stability and durability are required, such as underbody shields for vehicles.

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

[0004] U.S. Patent Application Publication No. 2016 / 0288451 discloses a nonwoven composite material that is moldable and can be used to manufacture a vehicle underbody. The nonwoven composite material comprises a layer of needle-stapled polyester fibers and a layer of spunbond polyester fibers, which are mechanically bonded to each other by needle-stapling.

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

[0006] However, known nonwoven composite materials and molded articles obtained therefrom can still be improved. 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 and loss of advantageous properties. Structural automotive components such as underbody shields, wheel arch liners, or engine shields are subjected to mechanical stress and strain over long periods. These components should maintain their integrity and properties even after prolonged use under harsh conditions. Vehicle structural components must also be resistant to flying debris, which occurs consistently during standard use and causes significant mechanical strain.

[0007] Summary of the Invention In one embodiment, the disclosure provides a spunbond nonwoven fabric comprising hollow polymer multi-component fibers and having a thickness of at least 1 mm according to DIN EN ISO 9073-2:1997-02.

[0008] The subject matter of this disclosure will be described in more detail below with reference to the illustrative drawings. All features described and / or described herein can be used individually or in various combinations. The features and advantages of various embodiments will become apparent by reading the following detailed description with reference to the accompanying drawings illustrating them below. [Brief explanation of the drawing]

[0009] [Figure 1] This graph shows a comparison of sound absorption (DIN ISO 10534-1) between needle-stapled fabric and hollow two-component spunbond fabric.

[0010] Modes for carrying out the invention In one embodiment, the present invention provides a novel material that at least partially overcomes the drawbacks encountered in the art. Improved products should be provided for structural components, particularly suitable for use in vehicles. The products should have high mechanical stability, yet be lightweight and suitable for long-term use. Preferably, the material should also have good acoustic properties and be recyclable.

[0011] It is particularly desirable for molded products to be lightweight. In fact, needle-punched staple fibers are more bulky and therefore can make molded products lighter. However, they have the disadvantage of not having the good mechanical properties that spunbond fibers possess. Furthermore, the manufacturing process for needle-punched staple fibers is very long and therefore costly. On the other hand, spunbond fibers have good mechanical properties but are not bulky and the fibers are smooth.

[0012] Therefore, it is desirable to provide a nonwoven fabric that is bulging, thereby giving the molded product lightness without sacrificing good mechanical properties.

[0013] It is advantageous if the material can be manufactured and molded in a simple and easy manner. The material should be low-cost and available through standard processing methods.

[0014] Surprisingly, it was found that the aforementioned advantages are achieved by spunbond nonwoven fabrics and molded articles according to embodiments of the present invention.

[0015] One embodiment of the present invention provides a spunbond nonwoven fabric comprising hollow polymer multi-component fibers and having a thickness of at least 1 mm according to DIN EN 9073-2 / 1997-02. In a preferred embodiment, the spunbond nonwoven fabric has a thickness in the range of 1 to 25 mm, preferably 2 to 16 mm, and particularly 4 to 10 mm, according to DIN EN 9073-2 / 1997-02.

[0016] One embodiment of the present invention provides a method for preparing a spunbond nonwoven fabric as defined herein, using hollow multi-component fibers comprising at least one type of hollow polymer fiber as defined above and below, wherein the spunbond nonwoven fabric is prepared by melt spinning or solution spinning of hollow multi-component fibers through a spinneret having an orifice pattern, wherein a single fiber is formed by passing a polymer molten material through a spinneret having a hollow portion, and in particular, the fiber exiting the spinneret is subjected to a single-step drawing process.

[0017] One embodiment of the present invention involves layer (A), layer (B), and layer (A) in that order. A spunbond nonwoven fabric layer (A) containing hollow polymer multi-component fibers and having a thickness of at least 1 mm according to DIN EN ISO 9073-2:1997-02, Adhesive layer (B), - A further spunbond nonwoven fabric layer (A) comprising hollow polymer multi-component fibers, preferably two-component fibers, and having a thickness of at least 1 mm according to DIN EN ISO 9073-2:1997-02. The present invention further provides a nonwoven fabric laminate that includes the above.

[0018] The layers A used in the nonwoven laminate may be identical or different. However, in either case, the general definition of a nonwoven fabric is met.

[0019] One embodiment of the present invention further provides a molded article comprising a spunbond nonwoven fabric as defined above and below, or a laminate as defined above and below.

[0020] One embodiment of the present invention further provides a structural component for a vehicle, comprising a molded article as defined above and below, preferably an underbody shield, a wheel arch liner, or an engine shield.

[0021] One embodiment of the present invention further provides a vehicle comprising molded articles and / or structural components as defined above and below.

[0022] One embodiment of the present invention is the use of the molded article defined above and below for applications in the automotive, marine, aerospace, and railway vehicle sectors, particularly as a structural part for vehicles, wherein the structural part is preferably an underbody shield, a wheel arch liner, or an engine shield, and further provides the use.

[0023] Spunbond nonwoven fabric: One embodiment of the present invention provides a spunbond nonwoven fabric comprising hollow polymer multi-component fibers and having a thickness of preferably 1 mm to 25 mm, more preferably 2 mm to 16 mm, particularly 4 mm to 8 mm, according to DIN EN ISO 9073-2:1997-02.

[0024] As used herein, the term non-woven relates to non-woven fabrics. This is a layer of fibers integrated by physical and / or chemical means excluding weaving, knitting, or papermaking. Generally, non-woven fabrics are defined by DIN EN ISO 9092:2018.

[0025] Spunbond generally refers to a fabric containing theoretically endless fibers drawn from a molten fiber raw material. The spunbond nonwoven layer (A) is preferably made of continuous filaments that are calendared together to form a sheet.

[0026] Multi-component fibers contain at least two (e.g., 2, 3, 4, or 5 or more) different polymer components. Multi-component fibers composed of two polymer components (bicomponent fibers) are preferred. Suitable types of bicomponent fibers are sheath / core fibers (also called core / shell fibers), side-by-side fibers, sea-island fibers, and piecing fibers.

[0027] In one embodiment, the multi-component fiber consists of at least two different polymers, and the melting point of one polymer is preferably at least 10 °C, more preferably at least 20 °C higher than the melting point of a second polymer that is also present in the fiber.

[0028] In further embodiments, the multi-component fiber includes or consists of core / sheath fibers, where the core material has a higher melting point and the sheath material has a lower melting point.

[0029] A preferred two-component fiber contains two polymer components selected from two different polyesters. Particularly preferred two different polyesters are polyethylene terephthalate (PET), copolyethylene terephthalate (Co-PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), cobutylene terephthalate (Co-PBT), polylactic acid (PLA), poly(ethylene succinate) (PES), poly(butylene succinate) (PBS), poly(ethylene adipate) (PEA), poly(butylene succinate-cobutylene adipate) (PBSA), and poly(ethylene succinate-cobutylene adipate). The following are selected from droxyacetic acid (PGA), poly(butylene succinate-cobutylene sebacate) (PBsu-co-BSe), poly(butylene succinate-cobutylene 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.

[0030] In particular, the two-component fiber contains two polymer components selected from polyethylene terephthalate, copolyethylene terephthalate (Co-PET), polyethylene naphthalate, and polybutylene terephthalate.

[0031] In one embodiment, the two-component fiber comprises polyethylene terephthalate (PET) and copolyethylene terephthalate (Co-PET), or consists of PET / Co-PET.

[0032] In the sense of this application, the term "Co-PET" refers to a copolymer of terephthalic acid, ethane-1,2-diol (ethylene glycol), and at least one further monomer. The further monomer is preferably selected from dicarboxylic acid monomers different from terephthalic acid, diol monomers different from ethane-1,2-diol, monomers containing at least one carboxylic acid group and at least one hydroxyl group (the hydroxyl group is polymerizable with the carboxylic acid group), and further monomers, as well as mixtures thereof. Suitable further acid monomers are aromatic, aliphatic, and alicyclic dicarboxylic acids. Suitable further aromatic dicarboxylic acid monomers are 2,6-naphthalenedicarboxylic acid and isophthalic acid. Suitable further aliphatic or alicyclic dicarboxylic acids are adipic acid, azelaic acid, sebacic acid, dodecanediic acid, cyclohexanedicarboxylic acid, and mixtures thereof.

[0033] Further suitable diol monomers distinct from ethane-1,2-diol include 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexane-dimethylanol, neopentyl glycol, and mixtures thereof.

[0034] Therefore, the term "Co-PBT" refers to a copolymer of terephthalic acid, butane-1,4-diol, and at least one further monomer. Suitable further diol monomers, distinct from ethane-1,2-diol, include 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexane-dimethylanol, neopentyl glycol, and mixtures thereof.

[0035] Copolymers of terephthalic acid, ethane 1,2-diol, and butane-1,4-diol can be represented as Co-PET or Co-PBT, depending on the amount of diol present.

[0036] 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 esterifying derivative (such as a halide or anhydride) with an aliphatic dihydroxy compound.

[0037] Preferably, the fibers forming the core of the two-component fiber and the fibers forming the shell are made of different materials. In particular, the fibers forming the core contain or consist of PET, and the fibers forming the shell contain or consist of Co-PET. Specifically, the PET:Co-PET ratio is in the range of 90:10 to 40:60.

[0038] Polyethylene terephthalate is a copolymer of terephthalic acid and ethane-1,2-diol (also known as ethylene glycol). In this specification, polyethylene terephthalate is also referred to as "PET". Polyethylene terephthalate may be unused polyethylene terephthalate (not recycled), recycled polyethylene terephthalate (also known as "r-PET"), or a mixture of unused and recycled polyethylene terephthalate. Unused polyethylene terephthalate allows for more precise setting of the mechanical properties of nonwoven laminates. Recycled polyethylene terephthalate can enable cost reduction of nonwoven laminates.

[0039] Polyethylene terephthalate can provide high uniformity in the mechanical properties of nonwoven fabrics. This can improve the uniformity of the elongation and tensile strength of the nonwoven fabric. This allows the nonwoven fabric to be easily heat-molded to provide the desired structure. As a result, the nonwoven fabric can be dimensionally stable when heat-molded. Polyethylene terephthalate can provide a relatively low basis weight in both the layers and the entire laminate.

[0040] Polyethylene terephthalate has a relatively high melting point of approximately 260°C. This allows it to possess high heat resistance and non-flammability. In this specification, the melting point is preferably determined according to DIN ISO 11357-3:2013.

[0041] The nonwoven fabric preferably comprises at least one copolyester in the form of a multi-component fiber used. The copolyester is a copolymer of a first dicarboxylic acid monomer, a first diol monomer, at least one second different dicarboxylic acid monomer, at least one second different diol monomer, and at least one further comonomer selected from comonomers different therefrom. Suitable copolyester-forming monomers are described for multi-component fibers, which are incorporated herein by reference.

[0042] The nonwoven fabric may also contain at least one polyester fiber distinct from polyethylene terephthalate. Suitable polyester-forming monomers and polyesters are those described for multi-component fibers. In particular, the polyester is selected from polyethylene naphthalate, polybutylene terephthalate, and mixtures thereof.

[0043] The nonwoven fabric may also contain additional fibers of at least one copolyester, distinct from the multi-component fibers described above. The additional fibers may comprise, or consist of, a copolyester of a first dicarboxylic acid monomer, a first diol monomer, at least one second distinct dicarboxylic acid monomer, at least one second distinct diol monomer, and at least one further comonomer selected from these different comonomers. Suitable copolyester-forming monomers are those described for the multi-component fibers, which are incorporated herein by reference.

[0044] Furthermore, suitable multi-component fibers are selected from at least two polymers, at least one of which is a polyolefin, particularly a polypropylene homopolymer or copolymer. A special embodiment is a two-component fiber comprising PP and Co-PP. The monomers are ethylene and 1,2-butylene.

[0045] The copolyester may be an amorphous copolyester, a crystalline copolyester, or a mixture of at least one amorphous copolyester and at least one crystalline copolyester.

[0046] The copolyester is preferably a copolymer of polyethylene terephthalate. The polyethylene terephthalate copolymer comprises terephthalic acid as a monomer, 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. The polyethylene terephthalate copolymer can facilitate the recycling of nonwoven fabrics. The polyethylene terephthalate copolymer can increase the peel strength within the nonwoven fabric. The polyethylene terephthalate copolymer can reduce the raw material cost of the nonwoven fabric.

[0047] The copolyester preferably has a melting point of 240°C or lower. More preferably, the copolyester has a melting point of 220°C or lower, even more preferably 210°C or lower, even more preferably 200°C or lower, even more preferably 190°C or lower, and particularly preferably 180°C. Copolyesters having a melting point of 240°C or lower can reduce the energy required to melt-bond the layers together. Copolyesters having a melting point of 240°C or lower can reduce the energy required to manufacture the spunbond layers (A) and (C) defined below. The energy reduction can continue to increase with lower melting points of 220°C or lower, 210°C or lower, 200°C or lower, 190°C or lower, and 180°C, respectively.

[0048] The copolyesters of layers (A), (B), and (C) are preferably basically neutral, i.e., have a pH value of 6.5 to 7.5, more preferably 6.8 to 7.2, and even more preferably 7.0. This helps to avoid undesirable chemical interactions between the surface of the nonwoven fabric and the environment.

[0049] Copolyester has a density of 1.1 to 1.6 g / cm³. 3 Preferably, it is 1.2 to 1.5 g / cm³. 3 It is more preferable that the concentration be 1.3-1.4 g / cm³. 3 It is even more preferable that the density is determined according to DIN EN ISO 1183-1:2019-09. Such a density can result in a nonwoven fabric of appropriate strength while avoiding excessive costs.

[0050] The copolyester is preferably a copolymer of polyethylene terephthalate, and more preferably the copolymer has a melting point of 240°C or lower. This simultaneously leads to increased peel strength, reduced costs, and reduced energy required for melt bonding of the layers and production of the spunbond layer.

[0051] Preferably, the binder polymer in the multi-component fiber is selected based on its melting point. In a preferred sheath-core configuration, the core is preferably made of PET, and the sheath is preferably made of a copolyester having a melting point of less than 200°C. One particularly preferred binder fiber has a sheath-core filament configuration. The core is made of PET having a melting point greater than 250°C, i.e., about 260°C, and the sheath contains a copolyester having a lower melting point in the range of 100°C to 200°C.

[0052] 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 and can be present in a spunbond nonwoven fabric. Preferably, the multicomponent filament has eight segments alternating from PET segments and copolyester segments. Alternatively, it may have a filament configuration of 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.

[0053] The sheath-core filament structure can be useful for spunbond nonwovens and multi-component staple fibers. A two-component filament configuration can consist of a sheath made 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, giving the material rigidity.

[0054] Side-by-side filament structures can be useful in spunbond nonwovens and multi-component staple fibers. A side-by-side filament configuration consists of one side of a low-melting-point copolymer and the other side of PET with a higher melting point. During the molding process, the low-melting-point copolyester melts, providing rigidity to the material.

[0055] The fibers have a cross-sectional area hollowness ranging from 2% to 25%, based on the total cross-sectional area of ​​the fiber. The total cross-sectional area of ​​the fiber is the sum of the cross-sectional area of ​​the hollow portion and the cross-sectional area of ​​the remaining fiber.

[0056] Preferably, the fibers have a cross-sectional hollowness in the range of 4 to 25% based on the total cross-sectional area of ​​the fibers, and in particular, a cross-sectional hollowness of multi-component fibers in the range of 6 to 12% based on the total cross-sectional area of ​​the fibers.

[0057] In one embodiment, the shape of the hollow portion may be circular, elliptical, triangular, quadrilateral, square, T-shaped, M-shaped, S-shaped, Y-shaped, or H-shaped.

[0058] In further embodiments, the hollow portion has a circular shape.

[0059] In a preferred embodiment, the fiber has only a single pore.

[0060] A spunbond nonwoven fabric according to one embodiment of the present invention is preferably thermoformable. Thermoforming is a manufacturing process in which a nonwoven fabric is heated to a molding temperature at which it becomes flexible, molded into a specific shape using a mold, and trimmed to produce a usable product.

[0061] The spunbond nonwoven fabric according to one embodiment of the present invention preferably has a density of 200-600 g / m², determined according to DIN EN 29073-1:1992-08. 2 It has a basis weight (also known as mass per unit area).

[0062] A spunbond nonwoven laminate according to one embodiment of the present invention preferably has a total mass of 400 to 2000 g / m² based on the total mass of spunbond nonwoven fabric in all layers, as determined according to DIN EN 29073-1:1992-08. 2 It has a basis weight (also known as mass per unit area).

[0063] A spunbond nonwoven fabric according to one embodiment of the present invention preferably has a sound absorption coefficient of more than 40%, measured in accordance with DIN ISO 10534-1 (2001) at a wall spacing of 10 mm and a frequency of 1600 to 2500 Hz, particularly 2000 Hz.

[0064] In one embodiment of spunbond nonwoven fabric, the density is 100 g / m².2 The fabric shall have a thermal insulation of at least 0.39 W / mK, as determined by DIN 52612 1979-09.

[0065] process: A hollow multi-component fiber according to one embodiment of the present invention is prepared by melt spinning or solution spinning through a spinneret orifice. In melt spinning, a molten polymer can be supplied to a spinneret plate, for example, by an extruder. Preferably, a single fiber is formed by a spinneret having a hollow portion. In particular, 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 by the composite plasticized polymer molten material exiting through the spinneret. In other words, the shape of the fiber is formed by the slots.

[0066] Preferably, in the process of one embodiment of the present invention, the fibers exiting the spinneret are subjected to a single drawing process (drawing process). In the drawing process, for example, the newly formed fibers exiting the orifice of the spinneret first pass through a heating zone, which is set to a temperature capable of causing plastic deformation of the fibers. Following the heating zone, there may be a cooling zone, in which the temperature of the fibers is reduced to below the glass transition temperature Tg. Cooling can be carried out in various ways known to those skilled in the art. When the fiber bundle exits the cooling zone, the temperature of the bundle should be sufficiently low so that the fibers or bundle can pass over or along a rotating or static induction element without permanent deformation. For drawing, the speed of the fibers exiting the spinneret orifice (spinning speed), as well as the heating and cooling zones, if present, are fixed. The speed can be set to a specific value, for example, by passing the fiber bundle through one or more godets several times. The godets can be heated if desired. Stretching and / or drawing yield the final mechanical properties and morphology of the fiber, particularly its fineness.

[0067] In a one-step drawing process according to one embodiment of the present invention, the fibers (i.e., the spun product) are drawn immediately after the spinning speed reaches a predetermined value.

[0068] In a preferred embodiment of the process of the present invention, the fibers emerging from the spinneret are aerodynamically stretched to obtain a desired strength. The filaments obtained in the spinning process can be deposited to form a nonwoven fabric. For example, the filaments obtained in the spinning process are deposited on a deposition belt, and the filaments overlap each other on the deposition belt.

[0069] In a more preferred embodiment of the process of the present invention, the spinning process can be carried out as a melt-blown process in which a high-pressure, high-temperature airflow is entrained with the molten material exiting the spinneret, resulting in the formation of thin fibers. These fibers can also be deposited to form a nonwoven fabric, which is mainly done on a deposit drum.

[0070] Nonwoven fabric laminate: In one embodiment, the present invention is characterized by layer (A), layer (B), and layer (A) in that order. - A spunbond nonwoven fabric layer (A) containing hollow polymer multi-component fibers and having a thickness of at least 1 mm, preferably 1 mm to 25 mm, more preferably 4 mm to 10 mm, according to DIN EN ISO 9073-2:1997-02, Adhesive layer (B), - A further spunbond nonwoven fabric layer (A) comprising hollow polymer multi-component fibers, preferably two-component fibers, and having a thickness of at least 1 mm, preferably 1 mm to 25 mm, more preferably 4 mm to 10 mm, according to DIN EN ISO 9073-2 / 1997-02. The present invention further provides a nonwoven fabric laminate that includes the above.

[0071] Melt bonding (thermal bonding) generally refers to a technique for joining polymer materials, usually thermoplastic materials, by applying heat to at least one material so that it partially melts or softens, bringing the materials into close contact, and then cooling them.

[0072] In a nonwoven laminate, layer (A) and the intermediate / adhesive layer (B) are preferably melt-bonded to each other, and more preferably, layer (A) and layer (B) are not mechanically bonded to each other. This can be achieved by forming a stack of layers and melt-bonding the stack. Melt-bonding all layers to each other can provide the nonwoven laminate with high uniformity in thermal shrinkage properties. This high uniformity in thermal shrinkage properties can reduce the formation of elephantiasis during molding. Due to the reduction in elephantiasis, the nonwoven laminate can have attractive aesthetics and higher flexural strength after molding. Melt-bonding the layers to each other can also provide the nonwoven laminate with high dimensional stability during heating and molding.

[0073] Layer (A) contains polyethylene terephthalate (PET) as defined above.

[0074] The adhesive layer (B) contains or preferably consists of CoPET, PP, CoPP, and CoPBT, and in particular, the polymer in the adhesive layer (B) has a melting point of 20°C or lower.

[0075] The nonwoven laminate may consist of layers (A) and (B). The nonwoven laminate may further include at least one further spunbond nonwoven layer (A), at least one further adhesive layer (B), preferably 1, 2, 3, 4, 5, 6, 7, 8 further nonwoven layers (A), preferably 1, 2, 3, 4, 5, 6, 7, 8, particularly 1, 2, 3, 4, 5 further nonwoven layers (A), particularly 1, 2, 3, 4, 5 further adhesive layers (B), in the order A, B, A, B, A, B, A, B, A, B, A.

[0076] The nonwoven laminate preferably does not contain inorganic reinforcing materials, particularly glass fibers. The absence of inorganic reinforcing materials, especially glass fibers, makes it easier to process.

[0077] The non-woven laminate preferably contains no blowing agent at all. Since there is no blowing agent at all, the non-woven laminate becomes environmentally sustainable. Since there is no blowing agent at all, the cost of an article containing the non-woven laminate can be reduced.

[0078] The spunbond non-woven layer (A) preferably has a basis weight of 300 g / m 2 ~2000 g / m 2 according to DIN EN 29073-1:1992-08. For applications in standard passenger cars, layer (A) preferably has a basis weight of 600~1500 g / m 2 and more preferably 700~1200 g / m 2 and most preferably 800~1000 g / m 2 according to DIN EN 29073-1:1992-08.

[0079] The spunbond non-woven layer (B) preferably has a basis weight of 20~200 g / m 2 and more preferably 30~80 g / m 2 according to DIN EN 29073-1:1992-08. The overall properties can be particularly advantageous when such a relatively lightweight spunbond layer is included.

[0080] For the entire non-woven laminate, it preferably has a basis weight of 300~2000 g / m 2 according to DIN EN 29073-1:1992-08. Preferably, the non-woven laminate has a thickness of 2~10 mm.

[0081] Such a non-woven laminate can be easily heat-formed to provide a desired configuration. It can be dimensionally stable during heat-forming. It is suitable for structural parts, especially vehicle structural parts. Due to the presence of layer (B), the peel strength and heat resistance can be increased.

[0082] One embodiment of the present invention provides a molded article comprising a nonwoven laminate according to an embodiment of the present invention. The molded article can be obtained by molding the nonwoven laminate in a mold ("mold"). Typically, molding is carried out under heat and / or pressure. After or during molding, the nonwoven laminate becomes integrated. Typically, the density increases and the porosity decreases, while the mechanical stability increases. The molded article can be molded into a specified form and shape. The molded article is typically rigid and can be cut. Overall, a mechanically stable and relatively lightweight article is obtained, which is suitable for automotive applications, such as underbody shields. Preferably, the molded part has the shape of a desired automotive part, such as an underbody shield.

[0083] In a preferred embodiment, the molded article is obtained by cold forming. In the cold forming process, the nonwoven laminate is preheated for 1 to 5 minutes, depending on the basis weight, preferably within a temperature range of 180°C to 220°C. This is to activate the low-melting-point copolyester, which acts as a binder. By activating the binder, it melts and forms a kind of adhesive between unused or recycled PET fibers. The binder 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. At this time, the compression mold can compress the entire or partial 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 cooled inside or outside the mold to cool the copolyester fibers in the staple fibers and spunbond components below their melting point. The nonwoven laminate is then transformed 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, thermal, or waterjet cutting.

[0084] In one embodiment, the present invention provides a molded article that takes advantage of the nonwoven laminates described herein. Particularly noteworthy is the effect of reducing the formation of an elephant hide-like state during molding, and the related advantages.

[0085] The molded article and / or nonwoven laminate has at least one of the following characteristics: According to ISO 178:2019-04, the bending strength is 250 MPa or more. According to ASTM 5034:2009, a tensile strength of 500N or more, and / or According to DIN EN 29073-3:1992-08, a tear strength of 100N or more is required. It is preferable that it has

[0086] The nonwoven laminate more preferably has a flexural strength of 250 MPa or more, more preferably 300 MPa or more, and even more preferably 400 MPa or more. The nonwoven laminate more preferably has a tensile strength of 500 N or more, more preferably 7500 N or more, and even more preferably 950 N or more. The nonwoven laminate more preferably has a tear strength of 100 N or more, more preferably 125 N or more, and even more preferably 140 N or more. 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 integration method. This can further enhance the mechanical properties of the nonwoven laminate, such as resistance to flying debris and material stability.

[0087] Nonwoven laminates and molded articles can be used in the automotive industry, and therefore for vehicles, but also for means of transport in general, i.e., for land, sea, or aerospace applications, such as aircraft, ships, or railway components. They are particularly suitable for structural components where high stability is required, especially for vehicles.

[0088] Nonwoven laminates or molded articles are particularly suitable for exterior applications, preferably for vehicle exterior applications. Preferred exterior applications include those subjected to high stress and strain, such as underbody shields, wheel arch liners, or engine shields. The advantages of the nonwoven laminates and / or molded articles described herein are beneficial for use in exterior applications. Particularly noteworthy are improved mechanical stability, resistance to flying debris and abrasion, high heat resistance, non-flammability, and sound absorption effects, as well as related advantages.

[0089] One embodiment of the present invention provides a structural component including a molded article of an embodiment of the present invention, preferably a structural component for exterior applications, preferably a vehicle structural component. The exterior component is preferably an underbody shield, wheel arch liner, or engine shield. One embodiment of the present invention provides an interior product including a molded article of an embodiment of the present invention, preferably a vehicle interior product. The interior product is preferably a panel, casing, cladding, reinforcement, or boarding. The interior product is preferably for a door, roof, trunk, or seat. One embodiment of the present invention provides a vehicle including a molded article and / or structural component of an embodiment of the present invention.

[0090] In further embodiments, nonwoven laminates and molded articles can be used for interior applications, particularly for vehicle interiors. Preferred interior applications include panels, casings, cladding, reinforcements, or boarding, such as doors, roofs, trunks, or seats. The advantages of the nonwoven laminates and / or molded articles described herein are beneficial for use in interior applications.

[0091] Nonwoven laminates are To prepare a spunbond nonwoven fabric / layer (A), Prepare spunbond nonwoven fabric / layers (A), (B), and (A) in order, The process involves melting and joining layers together. It can be manufactured in a process that includes [this].

[0092] The advantages of nonwoven laminates are beneficial in the process of manufacturing them. Particularly noteworthy is the effect of easy bonding of layers by melt bonding, which can lead to increased peel strength and related benefits.

[0093] The entire laminate is formed by establishing fused bonds between all the layers, but without mechanical bonds. The laminate is then ready to be molded into the desired shape for a specific application. The laminated structure is formed using either a cold forming or hot forming process.

[0094] One embodiment of the present invention further provides a molded article comprising a spunbond nonwoven fabric or a laminate according to an embodiment of the present invention.

[0095] Preferably, the molded article is obtained by cold forming or hot forming a spunbond nonwoven fabric or a nonwoven fabric laminate according to an embodiment of the present invention. The processes of cold forming and hot forming are known to those skilled in the art, and IR forming is a type of hot forming process.

[0096] One embodiment of the present invention further provides a structural component for a vehicle, including the molded article defined above, which is, for example, an underbody shield, a wheel arch liner, an engine shield, a switchgear unit, a transformer, particularly a distribution transformer or power transformer, an electric rotating machine, a generator, a motor, a drive, a semiconductor component, a power electronics device, or a converter station.

[0097] One embodiment of the present invention further provides a vehicle including the molded articles and / or structural components defined above.

[0098] One embodiment of the present invention further provides the use of a molded article according to an embodiment of the present invention as a structural component for a vehicle, preferably the structural component being an underbody shield, a wheel arch liner, or an engine shield.

[0099] Molded articles and nonwoven laminates solve the underlying problems of conventional solutions. These products possess high mechanical stability, good acoustic properties, recyclability, low weight, and low thermal shrinkage, and exhibit an effect of reducing elephantine-skin-like conditions. Furthermore, the material has high resistance to flying debris. Therefore, nonwoven composites and molded articles are highly suitable for applications in the automotive, marine, aerospace, and railway vehicle sectors. Nonwoven composites and molded articles are particularly suitable for structural components and / or exterior applications, especially for vehicles, such as underbody shields, wheel arch liners, or engine shields. The material is available at low cost and can be manufactured and molded in a simple and straightforward manner.

[0100] Example 1 A spunbond fabric containing two-component fibers, manufactured using a special spinning die, wherein the two-component fibers have a hollow portion within a core (inner core) surrounded by PET (outer core), and the outer core is surrounded by a low-melting-point PET polymer called 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 ratio of PET to Co-PET in the cross-section is 60:40, and the amount of the hollow portion of the core is 8%.

[0101] Table 1 shows a comparison of the mechanical properties of a spunbond fabric according to one embodiment of the present invention, which contains hollow polymer multi-component fibers, with the mechanical properties of a 100% needle-punched stapled fiber fabric containing 50% by weight of PET (6.7 dTex, 67 mm) and 50% by weight of PET:Co-PET (4.4 dTex, 51 mm). [Table 1]

[0102] The results of Example 1 demonstrate that the expanded spunbond fabric containing hollow polymer multi-component fibers according to an embodiment of the present invention has significantly better mechanical properties than 100% needle-punched staple fiber fabric. Although the staple fiber fabric contains a larger amount of Co-PET, its mechanical properties are inferior to those of the endless spunbond fabric according to an embodiment of the present invention. The 8% hollow portion contributes to better thermal insulation than its comparison.

[0103] Example 2: A spunbond fabric containing two-component fibers, manufactured using a special spinning die, wherein the two-component fibers have a hollow portion within a core (inner core) surrounded by PET (outer core), and the outer core is surrounded by a low-melting-point PET polymer called Co-PET. The PET forming the outer core has a melting point of 223°C, and the Co-PET has a melting point of 255°C. The ratio of PET to Co-PET in the cross-section is 80:20, and the amount of the hollow portion in the core is 6%.

[0104] Table 2 shows a comparison of the mechanical properties of a spunbond fabric according to one embodiment of the present invention, which contains hollow polymer multi-component fibers, with the mechanical properties of a 100% needle-punched stapled fiber fabric containing 50% PET (6.7 dTex, 67 mm) and 50% by weight PET:Co-PET (4.4 dTex, 51 mm), where the spunbond fabric contains hollow polymer multi-component fibers.

[0105] [Table 2]

[0106] The results of Example 2 demonstrate that the expanded spunbond hollow bicomponent fiber fabric according to the embodiment of the present invention has significantly better mechanical properties than 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 to better thermal insulation than its comparison.

[0107] Example 3: A spunbond fabric containing two-component fibers, manufactured using a special spinning die, wherein the two-component fibers have a hollow portion within a core (inner core) surrounded by PET (outer core), and the outer core is surrounded by a low-melting-point PET polymer called 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 ratio of PET to Co-PET in the cross-section is 60:40, and the amount of the hollow portion of the core is 8%.

[0108] Figure 1 shows a comparison of sound absorption (DIN ISO 10534-1) between needle-processed stapled cloth and hollow bico spunbond cloth according to an embodiment of the present invention.

[0109] The acoustic curves show that hollow two-component spunbond fabric exhibits better absorption than staple fiber fabric in the low and mid-frequency ranges. This is extremely important when considering the use of the material in automotive applications.

[0110] The subject matter of this disclosure is described and illustrated in detail in the drawings and the preceding description, but such descriptions and illustrations should be considered to be for illustrative or illustrative purposes only and not to limit. Since the present invention is defined by the claims, any descriptions of the present invention made herein should be considered to be for illustrative or illustrative purposes only and not to limit. Those skilled in the art will understand that modifications and alterations can be made within the following claims, which may include any combination of the features of the various embodiments described above.

[0111] The terms used in the claims should be interpreted to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article "a" or "the" when introducing an element should not be interpreted as excluding multiple elements. Similarly, the enumeration of "or" should be interpreted as inclusive, and the enumeration of "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 intended. Furthermore, the enumeration of "at least one of A, B and C" should be interpreted as one or more of the group of elements consisting of A, B and C, regardless of whether A, B and C are related as categories, and should not be interpreted as requiring at least one of each of the enumerated elements A, B and C. Furthermore, the enumeration of "A, B and / or C" or "at least one of A, B or C" should be interpreted as including any singular entity from the enumerated elements, e.g., A, any subset from the enumerated elements, e.g., A and B, or the entire list of elements A, B and C.

Claims

1. Contains hollow polymer multi-component fibers, Having a thickness of at least 1 mm in accordance with DIN EN ISO 9073-2:1997-02, Spunbond nonwoven fabric.

2. The spunbond nonwoven fabric according to claim 1, having a thickness in the range of 1 to 25 mm in accordance with DIN 9073-2 / 1997.

3. The spunbond nonwoven fabric according to claim 1, wherein the hollow polymer multi-component fiber includes a hollow two-component fiber.

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

5. The spunbond nonwoven fabric according to claim 1, wherein the hollow polymer multi-component 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, cobutylene terephthalate, polylactic acid, poly(ethylene succinate), poly(butylene succinate), poly(ethylene adipate), poly(butylene succinate-cobutylene adipate), polyhydroxyacetic acid, poly(butylene succinate-cobutylene sebacate), poly(butylene succinate-cobutylene adipate), poly(tetramethylene succinate), polycaprolactone, polypropliolactone, 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 multi-component 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, which is thermoformable.

9. Determined according to DIN EN 29073-1:1992-08, 200-600 g / m² ２ A spunbond nonwoven fabric according to claim 1, having a basis weight.

10. The spunbond nonwoven fabric according to claim 1, having a sound absorption coefficient of more than 40% when measured in accordance with DIN ISO 10534-1 with a wall spacing of 10 mm and a frequency of 1600 to 2500 Hz.

11. 100g / m ２ The spunbond nonwoven fabric according to claim 1, wherein the fabric has a thermal insulation property of at least 0.39 W / mK, as determined in accordance with DIN 52612 1979-09.

12. Hollow multi-component fibers are used, The spunbond nonwoven fabric is prepared by melt spinning or solution spinning of the hollow multi-component fibers through a spinneret having an orifice pattern, By passing the molten polymer through a spinneret having a hollow portion, a single fiber is formed. The fibers that have emerged from the spinneret are subjected to a single drawing process. A method for preparing the spunbond nonwoven fabric according to claim 1, comprising:

13. The layers are included in the order (A), (B), (A), Layer (A) is a spunbond nonwoven fabric layer containing hollow polymer multi-component fibers, and the spunbond nonwoven fabric has a thickness of at least 1 mm according to DIN EN ISO 9073-2:1997-02. Layer (B) is the adhesive layer. Nonwoven fabric laminate.

14. The nonwoven fabric laminate according to claim 13, wherein layer (A) and layer (B) are fused together.

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

16. Determined according to DIN EN 29073-1:1992-08, 300 g / m² ２ ~2000g / m ２ A nonwoven fabric laminate according to claim 13, having a basis weight.

17. The nonwoven laminate according to claim 13, further comprising at least one further spunbond nonwoven fabric layer and at least one further adhesive layer.

18. A molded article comprising the spunbond nonwoven fabric described in claim 1.

19. A vehicle structural component comprising the molded article described in claim 18.

20. A vehicle comprising the molded article described in claim 18.

21. The molded article according to claim 18, configured to be placed on an automobile, marine vehicle, aerospace vehicle, or railway vehicle.

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