Spunbond Nonwoven Laminate and Method for Producing a Spunbond Nonwoven Laminate

Abstract

The present invention relates to a laminate of spunbond nonwoven material comprising at least two layers of spunbond nonwoven material, wherein at least one layer comprises continuous crimped filaments. The continuous crimped filaments are multicomponent filaments, in particular two-component filaments having a first component based on polypropylene and a second component based on polypropylene. The specific density γ [g / cm³] of the laminate of spunbond nonwoven material depends on the mass per unit area of ​​the laminate of spunbond nonwoven material below a limiting density γG, which is defined by the following equation: (see Formula).

Description

Spunbond Nonwoven Laminate and Method for Manufactured Spunbond Nonwoven Laminate FIELD OF INVENTION The invention relates to a laminate of spunbond nonwoven material comprising at least two layers of spunbond nonwoven material, wherein at least one layer of spunbond nonwoven material comprises continuous crimped (or wavy) filaments or comprises or essentially consists of continuous crimped filaments, wherein the continuous crimped filaments are multicomponent filaments, in particular two-component filaments. The invention further relates to a method for producing a laminate of spunbond nonwoven material. It is within the scope of the invention that the continuous filaments comprise continuous filaments made of thermoplastic material. Due to their almost infinite length, continuous filaments differ from staple fibers, which have much shorter lengths, for example, from 10 mm to 60 mm. BACKGROUND OF THE INVENTION Spunbond nonwoven laminates of the type described above, and the corresponding methods for producing such laminates, are known from the prior art and practice in various forms. Many applications require nonwoven materials or nonwoven laminates that are thick and have the lowest possible mass per unit area. Thickness is usually achieved using crimped or wavy filaments. In this case, spirally crimped filaments are preferred. Multicomponent or two-component filaments are used to produce crimped filaments. To achieve crimping, it is sufficient if both components of the two-component filaments differ in the amplitude of their molar mass distribution.Other differences (viscosity, melting point, and generally different solidification processes) or combinations thereof also result in waviness. The maximum waviness achievable for a specific formulation is often only usable in slow, single-beam processes for producing individual spunbond nonwovens in all shapes. In multi-beam processes for the continuous production of various layers of spunbond nonwovens, this waviness is often too strong, resulting in an undesirable non-homogeneous deposit or a deposit with undesirable reduced dimensional stability. Until now, when a compromise was sought between high thickness and satisfactory filament deposition in multi-beam systems, it was generally at the expense of thickness.In the case of three-beam systems, and therefore triple the production speed, it is not uncommon to see a reduction in thickness from half to two-thirds of a single layer to produce nonwoven laminates with masses per unit area between 20 and 25 g / m². For multi-beam systems, the quality of the deposit could be improved by using thinner filaments. However, with thinner filaments (higher chamber pressure in the cooling chamber, more draft air during drawing, and lower yield), known prior art blends typically show a reduction in the thickness of the nonwoven material. The advantages of improved storage and productivity cannot be combined with increased thickness in this case. MA / t / ZUZZ / UZOO / o Fine fiber nonwoven materials are known from European patent EP 3 521 495 B1. These fine fiber nonwoven materials have good coverage and high-quality coating, and are characterized by a smooth and homogeneous surface. However, in multi-beam applications, their thickness leaves much to be desired. Multicomponent filaments or two-component filaments with a side-by-side or eccentric core-cover configuration are particularly useful for producing sufficient crimping and high thickness. Providing high thickness is typically associated with a relatively high mass per unit area of ​​the nonwoven material. This applies, on the one hand, to single-layer nonwoven materials, but especially to multi-beam nonwoven materials produced on multi-beam systems.Multi-layer production means that, on the one hand, the layers must be more tightly compacted or pre-consolidated in each case to avoid damaging the deposit of these layers when transferred to subsequent bundles. On the other hand, the initial layers must be further compacted when subsequent layers are deposited, and therefore the thickness of the spunbond nonwoven laminate is also significantly reduced compared to the good thicknesses achievable with single layers. Particularly in the case of multi-beam systems with, for example, three or more bundles, there is a conflict of objectives regarding achieving high thickness while simultaneously maintaining a low mass per unit area, and resolving this conflict has thus far presented insurmountable challenges for experts in the field.Until now, achieving a target thickness of nonwoven material has generally led to a disproportionate increase in the mass per unit area of ​​the nonwoven layer or laminate, or to a thick laminate with uneven placement. This also results in undesirably high material usage and, therefore, high costs. Therefore, a high thickness with the lowest possible mass per unit area is desirable. In this case, it must also be considered that such a laminate of spunbond nonwoven material must meet the requirements in terms of softness, strength, and, in particular, dimensional stability. Adequate strength and, especially, adequate dimensional stability are required for subsequent processing. In the case of known prior art laminates, the desired properties are achieved by means of reinforcing layers, for example, layers of nonwoven material without crimp or layers of nonwoven material with reduced crimp, or by combining a layer of stable fine-fiber nonwoven material (for example, with filaments having a linear density of less than 1.5 denier) with a denser web and medium crimp with a thicker layer of nonwoven material, using fibers that have a normal linear density (for example, 1.7 to 2 denier) and with greater crimp.However, in this case the mass per unit area of ​​the laminate is relatively high. BRIEF DESCRIPTION OF THE INVENTION The invention is based on the technical problem of providing a laminate of spunbond nonwoven material of the type mentioned at the beginning, which has a greater thickness with substantially constant material usage compared to nonwoven materials known in practice or the prior art, particularly when also produced in multi-beam systems, and at the same time also has optimal softness, high strength, and in particular high dimensional stability. The invention MA / t / ZUZZ / UZOO ! or additionally it is based on the technical problem of providing a corresponding method for producing a laminate of spunbond nonwoven material of this type. To solve this technical problem, the invention discloses a laminate of spunbond nonwoven material with at least two layers of spunbond nonwoven material, wherein at least one layer of spunbond nonwoven material comprises continuous wavy filaments or consists of, or essentially consists of, continuous wavy filaments, wherein the continuous wavy filaments are multicomponent filaments, in particular two-component filaments with a first component based on polypropylene and a second component based on polypropylene, and wherein the specific density ρ [g / cm3] of the laminate of spunbond nonwoven material depends on the mass per unit area of ​​the laminate of spunbond nonwoven material being below a limiting density qg which is defined by the following equation: 99 or - = 9--- » .''wc of ¡e. suverf'.ae ---r — 0.0393 r cn; ' c.'»;-c.»: Therefore, the specific limiting density qg depends linearly on the mass per unit area of ​​the spunbond nonwoven laminate. A laminate of spunbond nonwoven material according to the invention may consist of only two layers of spunbond nonwoven material, wherein at least one of these layers of spunbond nonwoven material comprises continuous crimped filaments. However, it is also within the scope of the invention that a laminate of spunbond nonwoven material according to the invention may have more layers or layers of nonwoven material and, for example, comprise two or more layers of spunbond nonwoven material with continuous crimped filaments and / or two or more layers of spunbond nonwoven material with filaments having little or no crimp. It is essential within the scope of the invention that there be at least two layers of spunbond nonwoven material in the laminate, of which at least one layer of spunbond nonwoven material has continuous crimped filaments. A highly recommended embodiment of the invention is characterized in that the first component of the multicomponent or two-component filaments consists of, or essentially consists of, a polypropylene blend, or consists of, or essentially consists of, a polypropylene copolymer (CoPP). The expression “essentially consists of” means in particular that the first component consists of at least 90% by weight, preferably at least 95% by weight, and preferably at least 98% by weight of the polypropylene blend or the polypropylene copolymer. This statement “essentially consists of” takes into account in particular the fact that, in addition to the aforementioned substance, additives and the like may also be contained in the first component. These additives are, in particular, active substances such as colorants, softeners / lubricants, surfactants, nucleating agents, or fillers such as chalk.The term “polypropylene blend” means in particular a blend of two or more homopolypropylenes or a blend of at least one homopolypropylene with at least one polypropylene copolymer or a blend of two or more polypropylene copolymers. “Polypropylene copolymer” also means, in particular, corresponding random copolymers. It is within the scope of the invention that the second component of the filaments ML / t / ZUZZ / UZOO / or multicomponent or bicomponent filaments comprise or consist substantially of polypropylene. The term “substantially” means in particular that the second component consists of at least 90% by weight, preferably at least 95% by weight, and preferably at least 98% by weight of polypropylene. In the context of the invention, the fact that the second component consists of, or consists essentially of, polypropylene means that the second component consists of, or consists essentially of, a homopolypropylene or consists of, or consists essentially of, a polypropylene copolymer. Fundamentally, the second component could also consist of, or consist essentially of, a polypropylene blend, in which case the definition given for the polypropylene blend applies in particular to the first component.Here, too, the additives may be contained as in the first component, although the type and proportion of the additives may differ between the components. A particularly preferred embodiment of the invention is characterized in that at least one layer of spunbond continuous filament nonwoven material comprises filaments having a linear density of up to 2 denier, preferably having a linear density of less than 2 denier, preferably having a linear density of less than 1.5 denier, particularly preferably from 1 to 1.7 denier, and most preferably from 1.2 to 1.7 denier. In this respect, the invention is based on the discovery that the solution to the technical problem is achieved by sufficiently crimping the filaments with finer filaments, where these finer filaments enable a stable web of the fabric and thus a dimensionally stable product. A highly preferred embodiment of the invention is characterized in that the continuous wavy filaments of at least one layer of spunbond nonwoven material have a core-cover configuration, and particularly preferably have an eccentric core-cover configuration. Conveniently, in this case, the first component of the multicomponent or two-component filaments forms the cover component, and the second component forms the core component. However, it is also within the scope of the invention that at least one layer of spunbond nonwoven fabric material having continuous wavy filaments has the filaments in a side-by-side configuration. In this case, one side of the filaments is formed by the first component, and the other side by the second component. A highly recommended embodiment of the invention is characterized in that at least 25% of all filaments or continuous filaments of the laminate according to the invention are continuous wavy filaments having a core-cover configuration, particularly an eccentric core-cover configuration. The aforementioned filament portion (fiber portion) is conveniently determined as follows: The laminate of spunbond nonwoven material is cut to a length of at least 10 mm, and an image produced by a scanning electron microscope (SEM) of the cut surface is taken and evaluated. The fiber portion of the filament type in question corresponds to the number of corresponding filaments in the field of view, based on all the filaments on the cut surface within the field of view. It is within the scope of the invention that, in the case of continuous corrugated filaments having an eccentric core sheath configuration, the filament sheath, viewed in the filament cross-section, has a constant or substantially constant thickness D over at least 20%, particularly at least 25%, preferably at least 30%, preferably at least 35%, and over at least 40% of the filament circumference. The thickness of the sheath in the region of its constant or essentially constant thickness D is conveniently from 0.1 to 4 pm, preferably from 0.1 to 3 pm, more preferably from 0.1 to 2 pm, and most preferably from 0.1 to 0.9 pm. It is recommended that the thickness D be at least 100 nm and that the thickness vary locally up to a maximum of 400 nm, particularly up to a maximum of 300 nm, preferably up to a maximum of 200 nm of the average thickness in the constant thickness range or in the essentially constant thickness range. A highly preferred embodiment of the invention is characterized in that the laminate according to the invention comprises at least three layers of spunbond nonwoven material, wherein at least one layer of spunbond nonwoven material comprises continuous wavy filaments, in particular comprising continuous wavy filaments with an eccentric core cover configuration, is disposed on an outer side of the laminate and wherein preferably the linear density of the continuous filaments of this layer of spunbond nonwoven fabric material is up to 2 deniers, preferably less than 2 deniers, particularly preferably less than 1.5 deniers, in particular from 1 to 1.7 deniers and most preferably from 1.2 to 1.7 deniers. A highly recommended embodiment of the invention is characterized in that the laminate of spunbond nonwoven material according to the invention has a mass per unit area in the range of 10 to 40 g / m2, particularly in the range of 12 to 35 g / m2, preferably in the range of 13 to 30 g / m2, preferably in the range of 14 to 25 g / m2 and most preferably in the range of 15 to 22 g / m2. It is within the scope of the invention that the first component of the multicomponent or bicomponent filaments be at least a polypropylene copolymer (CoPP) or have a polypropylene copolymer, wherein this first component preferably has a comonomer portion of 1 to 7% by weight, preferably 1.5 to 5% by weight. It has been shown that the softness of the laminate according to the invention can be improved by this embodiment. A layer of corresponding spunbond nonwoven material with these continuous wavy filaments is preferably disposed on the exterior or on a surface of the spunbond nonwoven laminate according to the invention.In this case, the continuous wavy filaments of this non-woven spunbond layer on the laminate surface are preferably continuous wavy filaments having an eccentric core cover configuration, and the aforementioned polypropylene copolymer is contained in the cover component of the continuous wavy filaments. A particularly recommended embodiment of the invention is characterized in that the first and second components of the multicomponent or bicomponent filaments have different melt flow rates (MFI), and in continuous filaments having a core-sheath configuration, preferably the second component forming the core component has a higher melt flow rate than the first component forming the sheath component. It is within the scope of the invention that the ratio between the melt flow rate of the second component, particularly the core component, and the melt flow rate of the first component, particularly the sheath component, is from 0.9 to 2.2 and preferably from 1 to 2. In the context of the invention, the melt flow rate is preferably measured in accordance with ISO 1133 in g / 10 min under conditions of 230°C and 2.16 kg. A particularly well-proven embodiment of the invention is characterized in that the ratio between the polydispersity index (Pl) of the first component, in particular the shell component, and the polydispersity index (Pl) of the second component, in particular the core component, is 0.9 to 1.4, and in particular 1 to 1.35. It is recommended that the first component, in particular the shell component, have a broader molar mass distribution than the second component, in particular the core component. In this case, the polydispersity index is the ratio of the weight average molar mass Mw to the number average molar mass Mn (PI=Mw / Mn). In this case, the average molar masses are measured by gel permeation chromatography (GPC), preferably in accordance with ISO 16014-1:2003, ISO 16014-2:2003, ISO 160144:2003 and ASTM D6474-12. The polydispersity index (PI=MW / Mn) is typically measured for pure polymers.For simplicity, it is assumed here that the polydispersity index of a polymer blend is composed of the polydispersity indices of the individual raw materials according to their proportions. The polydispersity index of a polymer blend made from polymers A and B is calculated according to the following formula: PI(Mixture A+B) = Portion AxPI(A) + Portion BxPI(B). A mixture of polymers with 60% A and 40% B then has a polydispersity index Pl (A+B) = 0.6χϡI (A) + 0.4χϡI (B). According to a recommended embodiment of the invention, the melting temperature of the first component, particularly the sheath component, is lower than the melting temperature of the second component, particularly the core component. In this case, the melting temperature difference is conveniently from 0 to 20°C, preferably from 1 to 18°C, and more preferably from 2 to 16°C. The invention is based on the discovery that, in this embodiment, less effort is involved in the thermal bonding of the nonwoven material layers and / or the nonwoven material laminate, since the sheath component melts more readily than the core component due to its lower melting temperature. It is recommended that the melting temperatures in the context of the invention be measured by DSC (differential scanning calorimetry) in accordance with ISO 11357-3. A preferred embodiment of the invention is characterized in that the second component, or the second component used as a core component, contains at least one lubricant, preferably at least 1000 ppm (referred to the entire filament). The invention is based on the discovery that the softness of the spunbond nonwoven laminate can be improved in this way, particularly if the nonwoven layer in question is disposed on a surface or exterior of the laminate. Adding it to the core component reduces contamination of the spunbond nonwoven layer as the lubricant evaporates. To solve the technical problem, the invention further teaches a method for producing a laminate of spunbond nonwoven material comprising at least two layers of spunbond nonwoven material, wherein at least one layer of spunbond nonwoven material is produced with continuous wavy filaments, in ML / t / ¿UZZ / U¿OO / or where the continuous wavy filaments are multicomponent filaments, in particular two-component filaments having a first component based on polypropylene and a second component based on polypropylene, wherein at least one layer of spunbond nonwoven material is compacted or pre-solidified by means of at least one hot roller and / or by means of at least one calender roller and / or by means of at least one hot air oven, wherein the laminate of spunbond nonwoven material is finally consolidated by means of at least one calender roller and wherein the laminate is produced with the condition that the specific density ρ [g / cm3] of the laminate of spunbond nonwoven material depends on the mass per unit area of ​​the laminate of spunbond nonwoven material and is below a limiting density ρο which is defined by the following equation: 3 S o- — 9 — · month, ce la suverf;c:e --r + 0.0393 —r It is within the scope of the invention that at least one layer of spunbond nonwoven material with continuous crimped filaments is compacted or pre-consolidated in the manner described. Additionally, it is within the scope of the invention that at least two, preferably all, layers of spunbond nonwoven material of the laminate of spunbond nonwoven material according to the invention are each compacted or pre-consolidated in the manner mentioned. A particularly preferred embodiment of the method according to the invention is characterized in that the final consolidation is carried out using at least one calender roll having an open-point engraving. In this case, the open-point engraving is characterized by an embossed or pressed surface of 8 to 15%, particularly 10 to 14%, and preferably 11 to 13%. It is recommended that the figure density of the calender roll for final consolidation be less than 35 figures per cm², particularly less than 30 figures per cm², and preferably 18 to 28 figures per cm². The area of ​​a figure is conveniently 0.25 to 0.75 mm², particularly 0.3 to 0.7 mm², where compact figures are preferred (circles, rhombuses, or ellipses having a length-to-width ratio of less than 2). It is recommended that the distance between the center points of two figures on the calender roller be between 0.9 and 2.5 mm, particularly between 1 and 2 mm. The engraving depth of the calender cylinder is preferably 0.4 to 1.0 mm, particularly 0.5 to 0.9 mm. It is also within the scope of the invention that the coverage or opacity of the spunbond nonwoven laminate according to the invention be improved by the addition of dye. For this purpose, the dye is uniformly dosed into all layers of the laminate. It is also within the scope of the invention that the dye be dosed only into specific layers of the nonwoven material. In this case, the color dosing is conveniently carried out in layers of nonwoven material that have a more uniform deposition, so that the optical uniformity for a given dye component can be optimized. The dye can be introduced in particular into layers of nonwoven material with less filament crimp, or into layers of nonwoven material without filament crimp, or also into layers of nonwoven material that have a higher mass per unit area. Essentially, MA / t / ZUZZ / UZOO / or layers with finer filaments are also possible.The definition according to the invention of the specific density ρ of the spunbond nonwoven laminate below the limiting density ρo refers to the manufacturing state of the spunbond nonwoven laminate according to the invention. However, normally, in the processing chain between its production, further processing, and packaging of the finished product, the spunbond nonwoven laminate will undergo compression acting on the laminate in the thickness direction. It is within the scope of the invention that the thickness of the laminate only recovers to a certain percentage. This percentage fraction of the thickness of the spunbond nonwoven laminate that does not recover from the original thickness after being subjected to compression is called the compression residual deformation and represents a permanent deformation of the spunbond nonwoven laminate.It is within the scope of the invention that the laminate of spunbond nonwoven material according to the invention has a maximum remnant deformation of 30%, in particular 20% and preferably 10%, so that the specific density ρ of the spunbond nonwoven material, especially when the final product is in use, is at most 30%, in particular at most 20% and preferably at most 10% above the limit density qg. The permanent compression deformation of the laminate according to the invention is conveniently determined as follows: the spunbond nonwoven laminate has an original thickness D1, which is measured under a pressure of 0.5 kPa. The spunbond nonwoven laminate is then loaded or compressed to 6 kPa for three days and then stored for three days without a load. After this time, the thickness D2 is measured. The compression set (DVR) is then calculated as follows: DVR = (Di-Dzj / Di). The measurement is repeated for at least five samples, and the average is then determined as the DVR. The density ρ of a laminate of spunbond nonwoven material according to the invention is preferably determined as follows: the air portion between the filaments of the laminate is neglected. The density then results from the ratio of the mass per unit area of ​​the laminate to the thickness of the laminate. The density of a spunbond nonwoven material having a mass per unit area of ​​50 g / m² and a thickness of 0.2 mm is then 50 / 0.2 = 0.25 g / cm³. It is within the scope of the invention that the spunbond nonwoven materials used in the laminate of the spunbond nonwoven material according to the invention, and in particular also at least one layer of spunbond nonwoven material with continuous crimped filaments, be produced by a spinning method. A preferred method of bonding by spinning for the spunbond nonwoven materials of the laminate of the spunbond nonwoven material according to the invention is described below. The continuous filaments for a spunbond nonwoven material or for a layer of spunbond nonwoven material are spun by means of a spinneret or spinning machine and then cooled in a cooling device with a cooling chamber. It is within the scope of the invention that a monomer suction device is located between the spinneret and the cooling device, by means of which interference gases produced during the spinning process can be removed from the device.After passing through the cooling device, the filaments are conveniently guided through a drawing device to stretch the continuous filaments. It is recommended that the drawing device have an intermediate channel. ML / t / ZUZZ / UZOO / or connect the cooling device to a drawing shaft of the drawing device. According to a particularly preferred embodiment of the invention, the unit comprising the cooling device and the drawing device or the unit comprising the cooling device, the intermediate channel and the drawing shaft is configured as a closed unit and, apart from the supply of cooling air to the cooling device, there is no further supply of air from the outside to this unit. At least one diffuser, through which the continuous filaments are guided, preferably follows the drawing device in the direction of filament flow. After passing through at least one diffuser, the continuous filaments are conveniently deposited onto a depositing device, which is preferably configured as a deposit sieve belt. It is recommended that the storage sieve belt be a continuously circulating sieve belt. Conveniently, the deposit sieve belt is configured to be air-permeable so that process air can be drawn from below through the deposit sieve belt. Conveniently, at least one suction device is provided for drawing process air from below the deposit sieve belt. The invention is based on the discovery that a high thickness and high softness can be achieved in a laminate of spunbond nonwoven material according to the invention, while still maintaining sufficiently high strength and dimensional stability. Furthermore, the filament deposition is characterized by satisfactory quality and sufficient homogeneity. With the method according to the invention, greater thickness and softness can be achieved compared to known prior art methods using virtually the same amount of material, and the resulting laminates are sufficiently strong and dimensionally stable. It should be emphasized that the advantages of the invention can be achieved through relatively simple measures and, therefore, at relatively low costs. Exemplary modalities: The plastics or polymers used in the following example embodiments are specified in more detail in Table 1 below. Here, the individual polymers are characterized by the letters A to G, which are used in the example embodiments. In addition to the manufacturer's name and polymer type, the melt flow rate (MFR) of the polymer in g / 10 min is given in the fourth column, and the melting point (TM) in degrees Celsius is given in the fifth column. The sixth column gives the mean molar mass (Mn), and the seventh column gives the mean molar mass (Mw). The eighth column relates to the mean molar mass (Mz), and the ninth column gives the polydispersity index (PI) = Mw / Mn. The Mw / Mz ratio of the mean molar masses is found in the last column. Polymers A to G are used in the following examples. Table 1: Polymer Manufacturer Name Type MFR g / 10 min TM °C Mn Mw Mz Mw / Mn (Pl) Mw / Mz A Moplen HP562T homopolypropylene 55 160 28000 152200 320100 5.4 2.1 B Exxon PP3155E5 homopolypropylene 35 159 30150 148500 307500 4.93 2.07 C Borealis HG475FB homopolypropylene 27 158 35800 166000 344000 4.6 2.07 D Moplen RP248R polypropylene copolymer 30 144 33600 152500 308000 4.54 2.02 E Moplen RP3386 polypropylene copolymer 30 144 33600 152500 308000 4.54 2.02 F Moplen RP348R polypropylene copolymer 25 148 28900 194750 569000 6.7 2.9 G Sabic PP511A homopolypropylene 25 161 36500 163500 340500 4.9 2.08 Tables 2 to 4 below relate to two-component filaments suitable for the invention, where components 1 and 2 are polypropylene-based. The abbreviation PP here signifies a homopolypropylene, and the abbreviation CoPP signifies a polypropylene copolymer. The addition of different digits (1, 2, or 3) indicates that they are either different homopolypropylenes or different polypropylene copolymers. Thus, for example, PP1 and PP2 are two different homopolypropylenes. The homopolypropylenes and polypropylene copolymers were selected from Table 1 above. The following should be taken into account for the assignment of the two components 1 and 2 of the two-component filaments in Tables 2 to 4 below: In the case of homopolypropylene combinations for components 1 and 2, the component with the narrowest molecular weight distribution (or with the smallest polydispersity index Pl) is component 1. In the case of homopolypropylene combinations with polypropylene copolymers (CoPP), the homopolypropylene is component 1 and the propylene copolymer is component 2. In the case of polypropylene copolymer combinations (CoPP / CoPP), component 2 is the component with the broadest molecular weight distribution (which has the highest polydispersity index Pl). Bicomponent filaments with side-by-side (S / S) configuration: The two-component filaments in Table 2 with a S / S configuration have a standard linear density of 1.5 to 2.0 denier. For components 1 and 2, the ratio of the melt flow rate of component 1 to the melt flow rate of component 2 is given in the third column. The ratio of the polydispersity index (Pl) of component 2 to the polydispersity index (Pl) of component 1 is listed in the fourth column. The absolute difference between the melting temperature of component 1 and the melting temperature of component 2 is given in the fifth column. Table 2: Component MFR Pl 1 / 2 2 / 1 ATm 1 - 2 1 2 PP1 PP1 + PP2 1.2-1.4 1.1 -1.3 < 5 °C PP1 PP2 + PP3 1.2-1.4 1.1-1.3 < 5 °C PP1 CoPP1 / CoPP1 + CoPP2 0.9 - 1.2 1.1-1.3 10 -15 °C PP1 CoPP1 + PP1 / CoPP1 + PP2 1.0-1.2 1.1-1.3 5-15°C Bicomponent filaments having an eccentric core-shell (eC / S) configuration: Table 3 below lists mixtures and parameters for two-component filaments according to the invention with an eC / S configuration and a standard linear density greater than 1.5 denier. Table 3: Component MFR 1 / 2 Pl 2 / 1 ATm 1 -2 1 2 PP1 PP1+ PP2 0.9-1.5 1.1 -1.4 < 5°C PP1 PP2 + PP3 0.9-1.5 1.1-1.4 PP1 CoPP1 0.9-1.5 1.1-1.4 10- 15°C PP1 CoPP1 + PP1 0.9-1.5 1.2-1.4 5-10 °C PP1 CoPP1 + PP2 0.9-1.5 1.2-1.4 5-10 °C PP1 CoPP1 + CoPP2 0.9-1.5 1.2-1.4 10- 15 °C Table 4 below refers to two-component filaments according to the invention with an eccentric core cover configuration having a fine linear density of less than 1.5 denier. Table 4: Component MFR 1 / 2 Pl 2 / 1 ATm 1 -2 1 2 PP1 CoPP1 + PP2 1.5-2.2 1-1.2 5 - 10 °C PP1 CoPP1 1.5-2.2 1-1.2 5 - 15 °C PP1 CoPP1+ CoPP2 1.5-2.2 1-1.2 5 - 15 °C PP1 PP1 +PP2 1.5-2.2 1-1.2 0 - 5 °C The raw materials and parameters or configurations for the production of three-layer spunbond nonwoven laminates are given in Tables 5 and 6 below. In this case, each laminate is produced using a three-beam system with beams 1, 2, and 3. Each beam preferably corresponds to the apparatus shown in Figure 1 for the production of spunbond nonwovens. Almost all the nonwoven layers of the three-layer spunbond nonwoven laminates have two-component crimped filaments with components 1 and 2. Only the middle or second layer of the nonwoven material in samples 5 and 12 comprises single-component filaments. The combinations of raw materials and polymers for each case are given in the second row of the tables below. Raw materials A through G can be found in Table 1. The mass ratio of the two components to each other for the samples is given in the third row of the tables below.The fourth line specifies the pressure in the cooling chamber of the spinning device used for the spun nonwoven layer. The last line indicates the polymer yield for the samples in the system in kg / h / m. Spinnerets with 6,800 capillaries / m were used to produce the nonwoven layers or corresponding filaments. The three-layer laminates were finally consolidated using a calender roll with an open-point embossed pattern. Table 5 specifies eight samples of three-layer spunbond nonwoven laminates according to the prior art. Each layer of samples 1 to 4 of the three-layer laminate comprises bicomponent crimped filaments in a side-by-side configuration with, specifically, a linear density of 1.2 denier. In these samples 1 to 4, the polymer of each component of the bicomponent filaments was provided with 5 wt% of a spinning aid. A Ziegler-Natta homopolypropylene with a melt flow rate of 1,200 g / 10 min and a melt temperature of 158°C was used as the spinning aid. Laminate samples 5 to 8 comprise filaments having a linear density of 1.7 denier. Almost all layers comprise two-component crimped filaments in a side-by-side configuration. Only the second or intermediate layer of sample 5 comprises single-component filaments without crimping, and the first layer of sample 8 comprises two-component filaments with a core-cover configuration without crimping. Table 5: Sample: 1 Batch 1 2 3 Raw materials G / DG / DG / D Mass ratio 70:30 50:50 60:40 Pressure chamber 5800 6200 5600 Yield kg / h / m 150 150 150 Sample: 2 Beam 1 2 3 Raw materials C / EC / EC / E Mass ratio 50:50 50:50 50:50 Pressure chamber 6500 6500 6500 Yield kg / h / m 155 155 155 Sample: 3 Beam 1 2 3 Raw materials C / EC / EC / E Mass ratio 50:50 50:50 50:50 Pressure chamber 6500 6500 6500 Yield kg / h / m 155 155 155 Sample: 4 Beam 1 2 3 Raw materials C / EC / EC / E Mass ratio 50:50 50:50 50:50 Pressure chamber 6500 6500 6500 Yield kg / h / m 155 155 155 Sample: 5 Beam 1 2 3 Raw materials C / DC / D Mass ratio 80:20 Mono Without ripple 70:30 Pressure chamber 3800 4200 3800 Throughput kg / h / m 200 200 200 Sample: 6 Beam 1 2 3 Raw materials G / DG / DG / D Mass ratio 90:10 60:40 50:50 Pressure chamber 4000 4000 3800 Yield kg / h / m 205 205 205 Sample: 7 Beam 1 2 3 Raw materials C / DC / DC / D Mass ratio 70:30 60:40 50:50 Pressure chamber 4500 4500 4000 Yield kg / h / m 250 250 250 Sample: 8 Beam 1 2 3 Raw materials G / DG / DG / D Mass ratio 70:30 No ripple 70:30 70:30 Pressure chamber 3800 4000 3800 Throughput kg / h / m 200 200 200 Table 6 below specifies four laminate samples (sample 9 to sample 12) of three-layer spunbond nonwoven laminates according to the invention. Each layer of the three-layer spunbond nonwoven laminates has crimped bicomponent filaments in an eccentric core-cover configuration. Only the middle or second layer of sample 12 has single-component filaments without crimping. The filaments in samples 9 and 10 have a linear density of 1.7 denier, the filaments in sample 11 have a linear density of 1.35 denier, and the filaments in sample 12 have a linear density of 1.3 denier. Regarding the raw materials specified in the second row, the first specified raw material is the core component, and the raw material mixture specified below is the cover component of the bicomponent filaments.The mass ratio given in the third line refers to the mass ratio of the core to the shell. The mass ratio given in the fourth line refers to the mass ratio of the polymer blend components to the shell component. Table 6: MA / t / ZUZZ / UZOO ! o Sample: 9 Beam 1 2 3 Raw materials B / D + CB / D + CB / D + C Mass ratio 85:15 80:20 70:30 Mass ratio D:C 70:30 80:20 80:20 Pressure chamber 4000 4000 3800 Yield kg / h / m 215 215 215 Sample: 10 Beam 1 2 3 Raw materials B / D + CB / D + CB / D + C Mass ratio 90:10 85:15 80:20 Mass ratio D:C 60:40 70:30 80:20 Pressure chamber 4000 4000 3800 Yield kg / h / m 215 215 215 Sample: 11 Beam 1 2 3 Raw materials A / D + CA / D + CA / D + C Mass ratio 90:10 70:30 70:30 Mass ratio D:C 60:40 75:25 75:25 Pressure chamber 4000 5800 5500 Yield kg / h / m 200 200 200 Sample: 12 Beam 1 2 3 Raw materials A / D + C only AA / D + C Mass ratio 70:30 70:30 Mass ratio D:C 50:50 75:25 Pressure chamber 5500 5800 5500 Yield kg / h / m 200 200 200 ML / t / ZUZZ / UZOO / o Table 7 below combines the essential parameters for the nonwoven laminates of all samples 1 to 12, where, as previously stated, samples 1 to 8 are samples produced according to the prior art and samples 9 to 12 are samples produced according to the teachings of the invention. The weight per unit area of ​​the nonwoven laminate is given in the second column and the linear speed or production speed in the third column. The fourth column gives the density of the nonwoven laminates in g / cm³. The last column gives the linear density in denier of the laminate filaments. Table 7: Sample Basis Weight (g / m2) Line Speed ​​(m / min) Density (g / cm3) Title (denier) 1 25 345 0.071 1.2 2 16.3 508 0.065 1.2 3 18.4 450 0.068 1.2 4 25.5 325 0.077 1.2 5 24.6 402 0.065 1.7 6 14.1 735 0.052 1.7 7 20.3 590 0.06 1.7 8 12.9 830 0.056 1.7 9 23.5 450 0.053 1.7 10 20 550 0.057 1.7 11 20.3 500 0.053 1.35 12 17 590 0.047 1.3 Figure 3 shows a diagram for samples 1 to 12 in which the density (g / cm³) of the entire spunbond nonwoven laminate is plotted as a function of the mass per unit area (g / m²) of the entire laminate. Examples 1 to 8 relating to the prior art show measurement points above the straight line according to the invention, which symbolizes the limiting density qg. The parameter values ​​for samples 9 to 12 according to the invention are below the straight line or below the limiting density. These spunbond nonwoven laminates are characterized by the advantages according to the invention, which will be explained below. Table 8 below shows the melt flow rate ratio of component 1 to component 2, as well as the polydispersity index ratio of component 2 to component 1 for the first layer of nonwoven material of the nonwoven laminates according to samples 1 to 12. MA / t / ¿UZZ / U¿OO / o Table 8: Sample IP Ratio 2 / 1 MF Range 1 / 2 1 1.0 0.83 2 1.07 0.9 3 1.07 0.9 4 1.07 0.9 5 1.07 0.9 6 1.0 0.83 7 1.07 0.9 8 No ripple No ripple 9 1.24 1.37 10 1.2 1.36 11 1.09 2.13 12 1.05 2.12 Table 9 below shows the melt flow rate ratio of component 1 to component 2, as well as the polydispersity index ratio of component 2 to component 1 for the three layers of nonwoven material from the nonwoven laminates according to samples 1 to 12. Table 9: Sample Basis Weight (g / m2) Line Speed ​​(m / min) Density (g / cm3) IP2 / 1 Ratio MF Range 1 / 2 1 25 345 0.071 1 / 1 / 1 0.83 / 0.83 / 0.83 2 16.3 508 0.065 1.07 / 1.07 / 1.07 0.9 / 0.9 / 0.9 3 18.4 450 0.068 1.07 / 1.07 / 1.07 0.9 / 0.9 / 0.9 4 25.5 325 0.077 1.07 / 1.07 / 1.07 0.9 / 0.9 / 0.9 5 24.6 402 0.065 1.07 / No Ripple / 1.07 0.9 / No ripple / 0.9 6 14.1 735 0.052 1 / 1 / 1 0.83 / 0.83 / 0.83 7 20.3 590 0.06 1.07 / 1.07 / 1.07 0.9 / 0.9 / 0.9 8 12.9 830 0.056 No ripple / 1 / 1 No ripple / 0.83 / 0.83 9 23.5 450 0.053 1.24 / 1.28 / 1.28 1.37 / 1.38 / 1.38 10 20 550 0.057 1.2 / 1.24 / 1.28 1.36 / 1.37 / 1.38 11 20.3 500 0.053 1.09 / 1.14 / 1.14 2.13 / 2.16 / 2.16 12 17 590 0.047 1.05 / No ripple / 1.14 2.12 / No ripple / 2.16 In Figure 4, which refers to Tables 8 and 9, the ratio of the melt flow rate of component 1 to the melt flow rate of component 2 is plotted against the ratio of the polydispersity indices of component 2 to the polydispersity index of component 1 for the raw materials of spunbond nonwoven laminates or spunbond nonwoven layers. In this case, in the diagram, the parameter points in the boxed area correspond to two-component filaments according to the invention (samples 9 to 12). On the other hand, to the left, below the horizontal line, the parameter points correspond to two-component filaments according to the prior art (samples 1 to 8). In the prior art, it is assumed that the stability of the yarn becomes progressively poorer for MFR ratios above the horizontal line.Additionally, for the first layer, it is assumed that for polydispersity index ratios to the right of the solid vertical line (b), thick layers of nonwoven material can be achieved by relatively strong crimp, where the degree of crimp may compromise dimensional stability and, therefore, the machine's performance. For the subsequent bundles 2 and 3, which begin to the right of the dashed vertical line (c) in Figure 4, there is a region where very strong crimp may compromise the deposit quality. On the other hand, in the area defined by the invention, fine filaments with good crimp and good yarn stability can be spun, allowing a laminate of spun nonwoven material with improved thickness and density to be deposited, according to the invention. The invention is based on the discovery that zone 1.1 in particular is preferable to zone 1.2, since finer filaments with good laminate density can be more easily obtained there (see also the diagram in Figure 3). In direction 2, as shown in the diagram in Figure 4, a gradual deterioration of spinneret stability is observed due to excessively low viscosities (excessively low molecular weights of the polypropylenes), resulting in a decrease in the strength of the nonwoven laminates. In direction 3, as shown in the diagram in Figure 4, spinneret stability is lost due to the combination of excessively broad molar mass distributions and excessively large viscosity differences, making fine filaments or filaments with low linear densities impossible. Finally, in direction 4, as shown in the diagram in Figure 4, fine filaments cannot be spun, although higher densities can be achieved due to the higher polydispersity index ratio. The relatively strong crimp results in uneven and sensitive filament deposits.Filaments with excessively high curl are always at risk of being displaced within the deposition area by horizontal air currents. Due to the relatively high linear density values, this effect is particularly pronounced here and cannot be controlled. This contrasts with area 1.1, which, according to the invention, has lower linear density values ​​and a more stable network of filament deposits. BRIEF DESCRIPTION OF THE FIGURES The invention is explained in more detail below with reference to figures that show only one example of an embodiment. They are shown in a schematic representation: Figure 1 shows a vertical section through a device for producing a layer of spunbond nonwoven material from a laminate of spunbond nonwoven material according to the invention, Figure 2 shows a cross-section through a preferred continuous filament with an eccentric core cover configuration and Figure 3 shows the density versus mass per unit area diagram, Figure 4 is a graph of the relationship between melt flow rate and polydispersity index ratio. DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a device for producing a layer of spunbond nonwoven material for spunbond nonwoven laminate according to the invention using the spinning method. At least one layer of spunbond nonwoven material with continuous wavy filaments for spunbond nonwoven laminate is also preferably produced using this device or with this method. The device comprises a spinneret 1 for spinning continuous filaments 2 for a layer of spunbond nonwoven material of the spunbond nonwoven laminate according to the invention. The continuous filaments 2 spun by the spinneret 1 are fed into a cooling device 3 with a cooling chamber 4. Preferably, and in the exemplary embodiment, the air supply chambers 5 and 6, arranged one above the other, are located on two opposite sides of the cooling chamber 4.Conveniently, air at different temperatures is introduced into the cooling chamber 4 from chambers 5 and 6, arranged one above the other. Preferably, and in the example configuration, an extraction device 7 is located between row 1 and the cooling device 3. With this extraction device... MA / t / ZUZZ / UZOO / or monomer 7, the interference gases produced during the spinning process can be removed from the device. It is recommended that, in the exemplary embodiment, a drawing device 8 for drawing the continuous filaments 2 be positioned further forward of the cooling device 3 in the direction of filament flow. Conveniently, in the exemplary embodiment, the drawing device 8 has an intermediate channel 9 connecting the cooling device 3 to a drawing shaft 10 of the drawing device 8. Preferably, in the exemplary embodiment, the unit comprising the cooling device 3 and the drawing device 8, or the unit comprising the cooling device 3, the intermediate channel 9, and the drawing shaft 10, is configured as a closed unit, and apart from the cooling air supply to the cooling device 3, no further air is supplied from outside to this unit. Conveniently, and in the exemplary embodiment, a diffuser 11 is attached to the drawing device 8 in the filament flow direction, through which the continuous filaments 2 are guided. After passing through the diffuser 11, the continuous filaments 2 are preferably deposited onto a depositing device configured as a deposit sieve belt 12. The deposit sieve belt 12 is conveniently configured, and in the exemplary embodiment, as a continuously circulating deposit sieve belt 12. It is within the scope of the invention that the deposit sieve belt 12 be air-permeable, so that process air can be drawn from below through the deposit sieve belt 12. For this purpose, conveniently, and in the exemplary embodiment, a suction device 13 is positioned below the sieve belt 12. Figure 2 shows a cross-section of a continuous filament 2 with an eccentric core cover configuration. Such continuous filaments 2 are preferably used for a layer of spunbond continuous filament nonwoven material in the laminate of spunbond nonwoven material according to the invention. This comprises a two-component filament having a first polypropylene-based component in the cover 14 and a second polypropylene-based component in the core 15. It can be observed in Figure 2 that, in the case of the preferred continuous filaments 2, the cover 14 of the filaments 2, in the cross-section of the filament, preferably and in the example embodiment, has a constant thickness D over more than 50% of the circumference of the filament. Preferably and in the example embodiment, the core 15 of the filaments 2, when viewed in the cross-section of the filament, is configured in the form of a segment of a circle.In the region of its constant thickness D, cover 14 preferably has a thickness D of 0.1 to 0.9 pm.

Claims

1. A laminate of spunbond nonwoven material comprising at least two layers of spunbond nonwoven material, characterized in that at least one layer of spunbond nonwoven material comprises continuous wavy filaments or consists of, or essentially consists of, continuous wavy filaments, wherein the continuous wavy filaments are multicomponent filaments, in particular the two-component filaments having a first component based on polypropylene and a second component based on polypropylene, and wherein the specific density ρ [g / cm3] of the laminate of spunbond nonwoven material depends on the mass per unit area of ​​the laminate of spunbond nonwoven material and remains below a limiting density ρo defined by the following equation: 1 3 3 o- = 9— «esc lío·· wxáac. de .r ec ---r — 0.0393 ---rf?': nm- c?>:3 2. The laminate of spunbond nonwoven material according to claim 1, further characterized in that the first component consists of, or essentially consists of, a mixture of polypropylene or consists of, or essentially consists of a copolymer of polypropylene.

3. The laminate of spunbond nonwoven material according to any of claim 1 or 2, further characterized in that the second component consists of, or essentially consists of, a polypropylene.

4. The laminate of spunbond nonwoven material according to any of claims 1 to 3, further characterized in that at least one layer of spunbond nonwoven material of the laminate comprises continuous wavy filaments having a linear density of up to 2 denier, preferably having a linear density of less than 2 denier, preferably having a linear density of 1 to 1.7 denier and particularly preferably 1.2 to 1.7 denier.

5. The laminate of spunbond nonwoven material according to any of claims 1 to 4, further characterized in that at least one layer of spunbond nonwoven material comprises continuous wavy filaments having a core-cover configuration, preferably having an eccentric core-cover configuration, and wherein preferably the first component is the cover component and the second component is the core component.

6. The laminate of spunbond nonwoven material according to any of claims 1 to 5, further characterized in that at least 25% of all filaments or continuous filaments of the laminate (fiber portion) are continuous wavy filaments having a core cover configuration, in particular having an eccentric core cover configuration.

7. The laminate of spunbond nonwoven material according to any of claim 5 or 6, further characterized in that in the continuous crimped filaments having an eccentric core cover configuration, the cover of the filaments, when viewed in the cross section of the filament, has a constant thickness D or a substantially constant thickness D over at least 20%, in particular over at least 25%, preferably over at least 30%, more preferably over at least 35% and particularly preferably over at least 40% of the circumference of the filament and wherein conveniently, the thickness of the cover in the region of its constant or substantially constant thickness D is from 0.1 to 4 pm, preferably from 0.1 to 3 pm, more preferably from 0.1 to 2 pm and most preferably from 0.1 to 0.9 pm.

8. The laminate of spunbond nonwoven material according to any of claims 1 to 7, further characterized in that the laminate comprises at least three layers of spunbond nonwoven material, wherein at least one layer of spunbond nonwoven material comprises continuous wavy filaments, in particular comprising continuous wavy filaments having an eccentric core cover configuration, is disposed on an outer side of the laminate and wherein preferably, the linear density of the continuous filaments of this layer of spunbond nonwoven material is up to 2 denier, preferably less than 2 denier, in particular from 1 to 1.7 denier and most preferably from 1.2 to 1.7 denier.

9. The laminate of spunbond nonwoven material according to any of claims 1 to 8, further characterized in that at least one layer of spunbond nonwoven material comprises continuous wavy filaments with a side-to-side configuration.

10. The laminate of spunbond nonwoven material according to any of claims 1 to 9, further characterized in that the laminate has a mass per unit area in the range of 10 to 40 g / m2, in particular in the range of 12 to 35 g / m2, preferably in the range of 13 to 30 g / m2, more preferably from 14 to 25 g / m2 and most preferably from 15 to 22 g / m2.

11. The laminate of spunbond nonwoven material according to any of claims 1 to 10, further characterized in that the first component comprises at least one polypropylene copolymer (CoPP), wherein the polypropylene copolymer preferably has a comonomer portion of 1 to 6% by weight, preferably 1.5 to 5% by weight.

12. The laminate of spunbond nonwoven material according to any one of claims 1 to 11, further characterized in that the first and second components have different melt flow rates and wherein continuous filaments have a core-cover configuration, preferably the second component constituting the core component having a higher melt flow rate than the first component constituting the cover component.

13. The laminate of spunbond nonwoven material according to any of claims 1 to 12, further characterized in that the ratio between the melt flow rate of the second component, in particular the core component, and the melt flow rate of the first component, in particular the cover component, is from 0.9 to 2.2, preferably from 1 to 2.

14. The laminate of spunbond nonwoven material according to any one of claims 1 to 13, further characterized in that the ratio of the polydispersity index (Pl) of the first component, in particular the cover component, to the polydispersity index (Pl) of the second component, in particular the core component, is from 0.9 to 1.4, in particular from 1 to 1.

35.

15. The laminate of spunbond nonwoven material according to any one of claims 1 to 14, further characterized in that the melting temperature of the first component, in particular the cover component, is lower than the melting temperature of the second component, in particular the core component, and wherein the melting temperature difference is suitably from 0 to 20°C, preferably from 1 to 18°C ​​and more preferably from 2 to 16°C. MA / t / ZUZZ / UZOO / o 16. The laminate of spunbond nonwoven material according to any one of claims 1 to 15, further characterized in that the second component, or the second component used as a core component, comprises at least one lubricant, and specifically comprises at least 1000 ppm (relative to the whole filament) of at least one lubricant.

17. A method for manufacturing a laminated material of spunbond nonwoven material, in particular as claimed in any of claims 1 to 16, characterized in that it comprises at least two layers of spunbond nonwoven material, wherein at least one layer of spunbond nonwoven material is produced from continuous crimped filaments, wherein the continuous crimped filaments are multicomponent filaments, in particular two-component filaments having a first component based on polypropylene and a second component based on polypropylene, wherein at least one layer of spunbond nonwoven material is compacted or pre-solidified by means of at least one heated roller and / or by means of at least one calender roller and / or by means of at least one hot air oven,wherein the laminate of spunbond nonwoven material is finally consolidated by means of at least one calender roll and wherein the laminate is produced with the condition that the specific density ρ [g / cm3] of the laminate of spunbond nonwoven material depends on the mass per unit area of ​​the laminate of spunbond nonwoven material remains below a limiting density qg which is defined by the following equation: 1 gg o- = 9 — > nrnic: ¿or umdac. de Área ---r — 0.0393 ---r c.”: cm- c?nJ, 18. The method according to claim 17, further characterized in that the final consolidation is carried out by means of at least one calender cylinder having an "open point" engraving.

19. A unit of nonwoven material characterized in that it comprises at least one laminate of spunbond nonwoven material as claimed in any of claims 1 to 16 and / or produced by a method as claimed in claims 17 or 18, wherein, due to compression, in particular during further processing or treatment, in the relaxed state, the laminate has a compression set (DVR) of at most 30%, in particular at most 20% and preferably at most 10%, and wherein the specific density ρ of the laminate is at most 30%, in particular at most 20% and preferably at most 10% above the limiting density qg.

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