Nonwoven fabric and method for manufacturing nonwoven fabric

Abstract

The present invention provides a nonwoven fabric and a method for manufacturing a nonwoven fabric that are characterized by high strength, particularly high tensile strength, and that can be manufactured easily, reliably, and economically. [Solution] A nonwoven fabric made of endless filaments is provided, wherein the filaments are multi-component filaments and comprise at least one first polypropylene component containing a base polypropylene and at least one second polypropylene component containing a base polypropylene. The difference in melting points between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component is less than 5°C. The base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component are polymerized using a catalyst from the same catalyst species.

Description

[Technical Field]

[0001] The present invention relates to a nonwoven fabric made of endless filaments, wherein the filaments are multi-component filaments, particularly two-component filaments, and comprise at least one first polypropylene component comprising a base polypropylene and at least one second polypropylene component comprising a base polypropylene. The present invention further relates to a method for producing such a nonwoven fabric. In the present invention, the filaments are endless filaments. Endless filaments differ from short fibers, which have obviously shorter lengths, for example, from 1 mm to 60 mm, in that they are substantially endless in length. It is within the framework of the present invention that the nonwoven fabric consists of or is essentially made of endless filaments. Here and below, the term filament is also used, in particular, instead of the term endless filament. [Background technology]

[0002] The aforementioned types of nonwoven fabrics and methods for manufacturing such nonwoven fabrics are known in principle in different embodiments in Praktis. In some applications, high strength of the nonwoven fabric, particularly high tensile strength, is required or desired. This relates in particular to tensile strength in the machine direction (MD) and / or transverse direction (CD) relative to the machine direction. In the context of this invention, the machine direction (MD) specifically refers to the conveying direction F of the nonwoven fabric on the stacking equipment. In contrast, CD or the CD direction refers to the transverse direction relative to the machine direction. It has been found that the strength characteristics achieved by nonwoven fabrics known from Praktis often do not meet all requirements. This applies not only to nonwoven fabrics made of one-component filaments but also to nonwoven fabrics made of multi-component filaments.

[0003] The strength or tensile strength of a nonwoven fabric is influenced, for example, by the strength of the individual filaments themselves (single filament strength), and also by the bonds present between each filament in the finished immobilized or final immobilized nonwoven fabric. These factors can also be influenced, in particular, by the selection of raw materials for the filaments. One-component filaments and nonwoven fabrics made from one-component filaments can be manufactured with relatively little effort, and nevertheless, the strength of the resulting filaments and nonwoven fabrics can be influenced by the selection of raw materials used. Furthermore, it is known from practice that the properties of nonwoven fabrics can be more precisely tuned by using multi-component filaments, especially two-component filaments, than the properties of nonwoven fabrics based on one-component filaments. For this purpose, the individual components of a multi-component filament can be optimized independently of each other with respect to specific desired properties of the resulting nonwoven fabric. In this way, the bonds between filaments in the finished nonwoven fabric and the strength of the individual filaments can be influenced with considerable precision.

[0004] However, it has been found that even using methods known from Praktis, the high strength, particularly tensile strength, required for some applications of nonwoven fabrics cannot be achieved to a satisfactory degree. Many nonwoven fabrics known from Praktis have strength or tensile strength that falls short of the desired level. This is the starting point of the present invention. [Overview of the project] [Problems that the invention aims to solve]

[0005] In contrast, the present invention is based on the objective of providing the aforementioned type of nonwoven fabric, characterized by high strength, particularly high tensile strength, and nevertheless being easily, reliably, and economically manufactured. Furthermore, the present invention is based on the technical objective of providing a method for manufacturing such a nonwoven fabric. [Means for solving the problem]

[0006] To solve the aforementioned technical problems, the present invention provides a nonwoven fabric made of endless filaments, wherein the filaments are multi-component filaments, particularly two-component filaments, and the nonwoven fabric comprises at least one first polypropylene component including a base polypropylene and at least one second polypropylene component including a base polypropylene. The difference in melting points between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component is less than 5°C, particularly less than 4°C, preferably less than 3°C, especially preferably less than 2°C, and most preferably less than 1°C. The base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component are polymerized using a catalyst from the same catalyst species, preferably using a metallocene catalyst or a Ziegler-Natta catalyst, respectively. This document provides instructions for the aforementioned nonwoven fabric.

[0007] The nonwoven fabric is final fixed, preferably thermally fixed or thermally bonded, and preferably includes an embossed pattern consisting of bonded areas, particularly bond points. Most preferably, the nonwoven fabric is final fixed or thermally fixed using a calender, the calender preferably comprising a first calender roller (gravure roller) having embossed elements on its outer surface and / or a second calender roller (S-roller) having a smooth outer surface.

[0008] In this invention, the difference in melting points between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component is less than 5°C. In this context, melting point also specifically refers to the melting temperature. The melting point or melting temperature of the base polypropylene is measured within the framework of this invention, particularly in accordance with ISO 11357-3:2011, using dynamic differential calorimetry (DSC).

[0009] In this invention, the base polypropylene of the first polypropylene component and the base polymer of the second polypropylene component are polymerized using a catalyst from the same catalyst species, preferably using a metallocene catalyst or a Ziegel-Natta catalyst, respectively. The phrase "same catalyst species" means, within the framework of this invention, that the same type of polymerization catalyst, for example, a homogeneous catalyst, a heterogeneous catalyst, or a mixed catalyst, was used for the polymerization of these base polypropylenes. In preferred embodiments, each base polypropylene of the first and second polypropylene components is polymerized using a Ziegel-Natta catalyst or a metallocene catalyst, respectively. Here, the catalyst species means, in particular, a metallocene catalyst or a Ziegel-Natta catalyst. Polypropylene polymerized using a metallocene catalyst is characterized by a narrow molecular weight distribution and / or high stereoregularity (particularly compared to polypropylene polymerized using a Ziegel-Natta catalyst). Within the framework of this invention, the molecular weight distribution of the polymer or polypropylene can be measured, in particular, according to ASTM D1238-13. In the measurement of the molecular weight distribution of polypropylene or base polypropylene in accordance with ASTM D1238-13, trichlorobenzene is used as the solvent for polypropylene plastics for practical purposes, and the measurement of the solution is carried out at a temperature of 160°C, with a concentration of 1.5 g / L, and an IR sensor is used. The column used in this measurement is calibrated using a polystyrene standard, and the measurement results are converted to "polypropylene" using the Mark-Howink formula. For practical purposes, the following parameter set is used: polystyrene: α=0.7; K=0.0138 mL / g, polypropylene: α=0.707; K=0.0242 mL / g.

[0010] It is within the scope of this invention that the second polypropylene component is arranged on the outer surface of the multi-component filament. The filament is a multi-component or bi-component filament having a core-sheath structure, particularly a concentric or symmetric core-sheath structure, in which case it is particularly preferable that the first polypropylene component forms the core of the filament and the second polypropylene component forms the sheath of the filament. The term "filament structure" within the scope of this invention specifically means the cross-sectional structure of the filament. In principle, other cross-sectional structures of nonwoven filaments, such as side-by-side structures, eccentric core-sheath structures, trefoil structures, or similar structures, are also within the scope of this invention.

[0011] The present invention relates to embodiments in which multi-component or bi-component filaments having a core-sheath structure, particularly a concentric or symmetric core-sheath structure, are used, and is based on the finding that the properties of the filament core and the filament sheath can be precisely influenced by the morphology of the first and second polypropylene components, and in this case, due to the very small difference in melting points set according to the present invention between each base polypropylene used and due to the polymerization of the base polypropylenes using catalysts from the same catalyst species, a filament can be realized that provides a nonwoven fabric characterized by remarkably high strength, particularly remarkably high tensile strength. The base polypropylenes are very similar in at least some of their properties (particularly with respect to their melting points or melting temperatures and their polymerization catalysts), resulting in a multi-component or bi-component filament that is as if (at least in respect to certain properties) a one-component filament, but in this case the strength value of the resulting nonwoven fabric is remarkably and clearly higher than that of a comparable one-component filament. This will be explained in more detail below. Similar findings are based on the form in which the multi-component or bi-component filament is formed in other cross-sectional structures, such as a side-by-side structure.

[0012] In the present invention, the first polypropylene component comprises base polypropylene (first base polypropylene), and the second polypropylene component comprises base polypropylene (second base polypropylene). Within the framework of the present invention, the term "base polypropylene" particularly means that the first polypropylene component and the second polypropylene component each contain base polypropylene in an amount of at least 55% by weight, particularly at least 60% by weight, and preferably at least 65% by weight. It is particularly preferable that the first polypropylene component and / or the second polypropylene component each contain base polypropylene in an amount of at least 70% by weight, particularly at least 80% by weight, preferably at least 85% by weight, especially preferably at least 90% by weight, and most preferably at least 92% by weight. It is even more preferable that the first polypropylene component and / or the second polypropylene component each contain base polypropylene in an amount of at least 94% by weight.

[0013] One embodiment of the nonwoven fabric according to the present invention, which is of particular importance within the framework of the present invention, is characterized in that the first polypropylene component and / or the second polypropylene component consist of or are essentially made from each base polypropylene. Within the framework of the present invention, when it is said that a component consists of or is essentially made from plastic (for example, the first polypropylene component consists essentially from (first) base polypropylene, and / or the second polypropylene component consists essentially from (second) base polypropylene), "essentially made from" means in particular that at least 95% by weight, preferably at least 98% by weight, and especially preferably at least 99% by weight of the component consists of the plastic. This takes into account in particular the situation that, in addition to the plastic, small amounts of additives, such as plasticizers, fillers, colorants, lubricants, additives (Zusatzstoffe) and the like may be present.

[0014] It is within the framework of the present invention that the first polypropylene component and / or the second polypropylene component are mixtures or blends of each base polypropylene and at least one additive. In one preferred embodiment, the additive may be a substance that increases the melt flow rate (MFR) of the first polypropylene component and / or the second polypropylene component. One particularly preferred embodiment of the present invention is characterized in that the second polypropylene component forms a sheath for a multi-component filament or a bi-component filament having a core-sheath structure, and the second polypropylene component is a mixture or blend of the base polypropylene of the second polypropylene component and at least one additive. In principle, the additive may also be a substance that can adjust other properties of each polypropylene component. For example, an additive having a peroxide component can be used that can achieve a reduction in the molecular weight of the base polypropylene.

[0015] Within the framework of the present invention, it is particularly preferable to use different polypropylenes as the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component. In this case, the phrase "different polypropylenes" means that the two base polypropylenes differ in at least one property, for example, with respect to their melting point and / or their molecular weight distribution and / or their stereoregularity and / or their melt flow rate (MFR). This embodiment in which different polypropylenes are used as the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component is particularly important within the framework of the present invention. Hereafter, the term "first base polypropylene" will be used in particular for the base polypropylene of the first polypropylene component, and the term "second base polypropylene" will be used in particular for the base polypropylene of the second polypropylene component.

[0016] In one alternative embodiment of the present invention, the same polypropylene is used as the base polypropylene of the first polypropylene component and as the base polypropylene of the second polypropylene component, wherein at least one polypropylene component, in particular at least the second polypropylene component, is a mixture or blend of the base polypropylene and at least one additive. More preferably, according to one embodiment, the second polypropylene component, which is a mixture or blend of the base polypropylene and at least one additive, forms the sheath component of a multicomponent filament or a bicomponent filament having a core-sheath structure as provided in the preferred embodiment.

[0017] Within the scope of the present invention, the proportion of the at least one additive in the first polypropylene component and / or the second polypropylene component is 0.1 to 30.0% by weight, particularly 0.2 to 20.0% by weight, preferably 0.5 to 15.0% by weight, especially preferably 1.0 to 10.0% by weight, most preferably 1.5 to 9.0% by weight, even more preferably 2.0 to 8.0% by weight, for example, 3.0 to 6.0% by weight. More preferably, the at least one additive is an additive polypropylene. In a very preferred embodiment, the additive polypropylene is a polypropylene having a higher melt flow rate (MFR) than the base polypropylene to which the additive or the additive polypropylene is mixed. This makes it possible to purposefully increase the melt flow rate (MFR) of the resulting polypropylene component. According to one embodiment, at least the second polypropylene component contains an additive in the form of added polypropylene, particularly in the proportions described above, and more preferably, this second polypropylene component forms the sheath component of a multi-component filament or a bi-component filament having a core-sheath structure provided according to the preferred embodiment.

[0018] In the present invention, the difference in melting points between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component is less than 5°C, particularly less than 4°C, preferably less than 3°C, especially preferably less than 2°C, and most preferably less than 1°C. It is within the scope of the present invention that the difference in melting points between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component is between 0.5°C and 5°C, particularly between 1°C and 4°C. One particularly important embodiment within the scope of the present invention is characterized in that the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component have the same or essentially the same melting points, and these are, particularly preferably, different polypropylenes or base polypropylenes. Having the same or essentially the same melting points as the base polypropylene of the first polypropylene component means, within the scope of the present invention, that the difference in melting points between the two base polypropylenes is 0°C or about 0°C.

[0019] One preferred embodiment of the present invention is characterized in that the melt flow rate (MFR) of the second polypropylene component is higher than that of the first polypropylene component, wherein the ratio of the melt flow rate (MFR) of the second polypropylene component to that of the first polypropylene component is particularly between 1.02 and 10, especially between 1.05 and 8, preferably between 1.1 and 6, particularly preferably between 1.2 and 3, and most preferably between 1.3 and 2.2, for example between 1.35 and 2.0. This embodiment is based on the finding that the resulting nonwoven fabric is characterized by favorable bonding between each filament (particularly after the final immobilization treatment), thereby further improving the strength or tensile strength of the nonwoven fabric. This is particularly true when the second polypropylene component is arranged on the outer surface of the filament according to the preferred embodiment and preferably forms a sheath component of a multi-component filament or a bi-component filament having a core-sheath structure. Within the framework of this invention, the melt flow rate is measured in grams of polymer per 10 minutes (g / 10 min) under conditions of 230°C and 2.16 kg (condition B), in particular, according to ASTM D1238-13. The melt flow rate (MFR) of a mixture or blend is determined by measuring the melt flow rate (MFR) of polypropylene or base polypropylene and by using logarithmic calculations for calculating the melt flow rate of the blend or mixture.

[0020] Preferably, the first polypropylene component has a melt flow rate (MFR) of at least 10 g / 10 min, particularly at least 12 g / 10 min, and / or preferably, the second polypropylene component has a melt flow rate (MFR) of at least 15 g / 10 min, particularly at least 20 g / 10 min. In principle, it is also within the scope of the present invention that the melt flow rate (MFR) of the first polypropylene component is higher than that of the second polypropylene component.

[0021] It is within the scope of the present invention that the ratio of the mass of the first polypropylene component to the mass of the second polypropylene component is between 95:5 and 50:50, particularly between 90:10 and 55:45, preferably between 85:15 and 60:40, especially preferably between 85:15 and 65:35, and most preferably between 85:15 and 70:30, for example between 80:20 and 75:25. This embodiment is based on the finding that by selecting the mass ratio of the polypropylene components, an optimal compromise can be achieved between the influence of the bonding sites that occur between the filaments of the nonwoven fabric (especially after final immobilization) on the strength or tensile strength of the nonwoven fabric and the influence of the individual filament strength on the strength or tensile strength of the nonwoven fabric. This is especially true when the second polypropylene component is arranged on the outer surface of the filament according to a preferred embodiment and, in particular, forms the sheath component of a multi-component filament or a bi-component filament having a core-sheath structure.

[0022] One particularly preferred embodiment of the nonwoven fabric according to the present invention is characterized in that the base polypropylene of the first polypropylene component and / or the base polypropylene of the second polypropylene component and / or at least one additive polypropylene is homo-polypropylene or polypropylene copolymer.

[0023] It is within the scope of the present invention that the nonwoven fabric has only one nonwoven layer made of endless filaments. However, it is also within the scope of the present invention that the nonwoven fabric includes multiple nonwoven layers arranged in a stack, which are combined, in particular, as a single nonwoven laminate. Therefore, according to one preferred embodiment, the nonwoven fabric has only one nonwoven layer made of endless filaments, where the basis weight of the nonwoven fabric is, in particular, 20 g / m². 2 From 110g / m 2 Up to, preferably 25 g / m² 2 From 85g / m 2 Up to, very preferably 30 g / m 2 From 75g / m 2up to. According to one alternative preferred embodiment, the non-woven fabric has at least two, preferably at least three, particularly three, non-woven fabric layers made of endless filaments. Here, the basis weight of the non-woven fabric is especially 1 g / m 2 and 20 g / m 2 in between, preferably 2 g / m 2 to 19 g / m 2 up to, very preferably 5 g / m 2 to 18 g / m 2 up to. Advantageously, these at least two non-woven fabric layers are combined into one non-woven fabric laminate. In the embodiment having at least two, especially at least three, particularly three non-woven fabric layers, it is within the scope of the present invention that the characteristics of these non-woven fabric layers or the characteristics of the filaments of these non-woven fabric layers are the same or essentially the same. However, in principle, it is also possible that the non-woven fabric layers or the filaments of the non-woven fabric layers are different from each other with respect to their characteristics. However, an embodiment in which at least two, particularly at least three, especially three identical or essentially identical non-woven fabric layers are stacked on top of each other and more preferably these layers are combined as one non-woven fabric laminate is preferred.

[0024] The non-woven fabric having a basis weight of 20 g / m 2 to 110 g / m 2 up to, especially 25 g / m 2 to 85 g / m 2 up to, preferably 30 g / m 2 to 75 g / m 2 up to is within the scope of the present invention. According to yet another preferred embodiment, the non-woven fabric has a basis weight of 1 g / m 2 and 20 g / m 2 in between, especially 2 g / m 2 to 19 g / m 2 up to, preferably 5 g / m 2 to 18 g / m 2 up to.

[0025] It is particularly preferable that the nonwoven fabric is final-fixed, especially thermally fixed, and has an embossed pattern consisting of bonding sites, particularly bonding points. This is very preferably a nonwoven fabric that is thermally fixed or thermally bonded using a calender. The preferred properties of the nonwoven fabric described below relate, in particular, to such final-fixed or thermally fixed nonwoven fabrics.

[0026] One preferred embodiment of the present invention is that the nonwoven fabric is 20 g / m² 2 From 110g / m 2 Up to, especially 25g / m 2 From 85g / m 2 Up to, preferably 30 g / m 2 From 75g / m 2 The basis weight is up to a certain amount, and preferably the specific tensile strength of the nonwoven fabric in the MD direction is 1 g / m². 2 From 2.5 to 7.2 N / 5cm, especially 1 g / m 2 3.0 to 7.0 N / 5cm, preferably 1 g / m 2 The pressure range is 3.2 to 6.8 N / 5cm, with a particularly preferred 1 g / m². 2 The N / 5cm range is 3.4 to 6.7 N, with a particularly preferred N / 5cm. 2 The specific tensile strength of the nonwoven fabric is 3.5 to 6.5 N / 5cm and / or preferably 1 g / m² in the CD direction. 2 From 2.0 to 4.0 N / 5cm, especially 1 g / m 2 The pressure range is 2.1 to 3.8 N / 5cm, preferably 1 g / m². 2 2.2 to 3.7 N / 5cm, particularly preferably 1 g / m 2 It is characterized by a pressure range of 2.3 to 3.6 N / 5 cm.

[0027] The nonwoven fabric has a weight of 20 g / m². 2 From 110g / m 2 Up to, especially 25g / m 2 From 85g / m 2 Up to, preferably 30 g / m 2 From 75g / m 2The present invention includes having a basis weight up to a certain amount, in which, for purposeful purposes, the tensile strength of the nonwoven fabric in the MD direction is from 100 N / 5 cm to 500 N / 5 cm, particularly from 120 N / 5 cm to 480 N / 5 cm, and / or the tensile strength of the nonwoven fabric in the CD direction is from 70 N / 5 cm to 350 N / 5 cm, particularly from 90 N / 5 cm to 320 N / 5 cm. A nonwoven fabric having the basis weight and tensile strength or specific tensile strength values ​​described above is, in particular, a single-layer nonwoven fabric having only one nonwoven layer. The above-mentioned properties of the nonwoven fabric relating to tensile strength apply in particular to nonwoven fabrics that are final-fixed, particularly thermally final-fixed, and preferably have an embossed pattern consisting of bonding sites, particularly bonding points.

[0028] One yet another or alternative preferred embodiment of the present invention is that the nonwoven fabric is 1 g / m² 2 and 20g / m 2 Between these two, in particular, 2g / m 2 From 19g / m 2 Up to, preferably 5 g / m 2 From 18g / m 2 The basis weight is up to a certain amount, and preferably the specific tensile strength of the nonwoven fabric in the MD direction is 1 g / m². 2 From 1.5 to 4.5 N / 5cm, especially 1 g / m 2 The N / 5cm range is 1.7 to 4.0 N, preferably 1 g / m². 2 The load capacity is 1.8 to 3.8 N / 5cm, particularly preferably 1 g / m². 2 From 2.0 to 3.5 N / 5cm, with a particularly preferred 1 g / m² 2 The specific tensile strength of the nonwoven fabric is 2.0 to 3.0 N / 5cm and / or preferably 1 g / m² in the CD direction. 2 From 1.0 to 2.5 N / 5cm, especially 1 g / m 2 1.1 to 2.0 N / 5cm, preferably 1 g / m 2 The N / 5cm range is 1.2 to 1.9 N / m², with a particularly preferred N / 5cm. 2 It is characterized by having a density of 1.2 to 1.8 N / 5cm. The nonwoven fabric is 1 g / m 2 and 20g / m2 Between these two, in particular, 2g / m 2 From 19g / m 2 Up to, preferably 5 g / m 2 From 18g / m 2 The nonwoven fabric has a basis weight up to a certain value, and in this case, for purposeful purposes, it is more preferable that the tensile strength of the nonwoven fabric in the MD direction is from 20 N / 5 cm to 40 N / 5 cm, preferably from 22 N / 5 cm to 38 N / 5 cm, and / or the tensile strength of the nonwoven fabric in the CD direction is from 8 N / 5 cm to 22 N / 5 cm, preferably from 10 N / 5 cm to 21 N / 5 cm. The nonwoven fabric having the basis weight and tensile strength value or specific tensile strength value described above is in particular a nonwoven fabric having at least two, especially at least three, especially three nonwoven layers, these nonwoven layers are preferably combined as a single laminate. The above properties of the nonwoven fabric relating to tensile strength are in particular a nonwoven fabric that is final fixed, especially thermally fixed, and preferably has an embossed pattern consisting of bonding sites, especially bonding points.

[0029] The tensile strength of the nonwoven fabric according to the present invention is determined, within the framework of the present invention, in particular, according to the following method: "Determination of tensile strength (based on EDANA 20.2-89)" Unit: N / 5cm; Sample width: 50 mm; Fixed length: 100 mm; Test speed: 200 mm / min.

[0030] As already described above, the nonwoven fabric is preferably final-fixed, particularly thermally final-fixed, and has an embossed pattern consisting of bonding sites, particularly bonding points. Within the framework of the final-fixing treatment, for the purposes of purpose, the nonwoven fabric is final-fixed, particularly by a calender, and for this purpose preferably, removed from the loading equipment that guides the nonwoven fabric. In contrast, a preliminary-fixing treatment is useful, in particular, for preliminary-fixing or compacting the nonwoven fabric for further transport without damage on the loading equipment. The embossed pattern is introduced to the nonwoven fabric, in particular, within the framework of the final-fixing treatment. For the purposes of purpose, the embossed pattern is introduced to the nonwoven fabric by at least one calender roller having a complementary embossed pattern consisting of embossed elements.

[0031] Within the framework of the present invention, the nonwoven fabric has an embossed pattern consisting of bonding sites, particularly bonding points, and the pore volume ratio in the area of ​​bonding sites is between 1.0% and 12.0%, particularly between 1.5% and 10.0%, preferably between 2.0% and 7.0%, and most preferably between 2.5% and 6.5%. Within the framework of the present invention, the pore volume ratio specifically means the ratio of the volume of pores to the total volume of bonding sites. Within the framework of the present invention, the pore volume ratio in the area of ​​bonding sites is determined, particularly by micro-computed tomography (μCT). Additionally or alternatively, the pore volume ratio in the area of ​​bonding sites can be determined by porometry using a porosimeter or autoporosimeter. Embodiments of the nonwoven fabric according to the present invention having an embossed pattern consisting of bonding sites and having a pore volume ratio in the area of ​​bonding sites within the range described above are based on the finding that using such low porosity in the area of ​​bonding sites can further increase the strength or tensile strength of the nonwoven fabric. In particular, nonwoven fabrics having a pore volume within the range of bonding locations described above are 20 g / m² 2 From 110g / m 2 Up to, preferably 25 g / m² 2 From 85g / m 2 Up to, more preferably 30 g / m 2 From 75g / m 2 It has a basis weight up to [a certain amount].

[0032] One particularly preferred embodiment of the nonwoven fabric according to the present invention is characterized in that the tensile strength and / or specific tensile strength of the nonwoven fabric in the MD direction and / or CD direction is more than 4%, particularly more than 6%, especially more than 10%, preferably more than 15%, and especially preferably more than 20%, higher than the corresponding tensile strength and / or specific tensile strength of a comparative nonwoven fabric manufactured from a one-component filament made of a first polypropylene component or a second polypropylene component under the same conditions. It is even more preferable that the tensile strength and / or specific tensile strength of the nonwoven fabric in the MD direction and / or CD direction is more than 25%, particularly more than 30%, especially more than 40%, preferably more than 50%, even more preferably more than 60%, especially more preferably more than 70%, and especially especially more preferably more than 80%, for example more than 90%, higher than the corresponding tensile strength and / or specific tensile strength of a comparative nonwoven fabric manufactured from a one-component filament made of a first polypropylene component or a second polypropylene component under the same conditions. The above characteristics are particularly applicable to nonwoven fabrics that are final fixed, especially thermally fixed, and preferably have an embossed pattern consisting of bonding sites, particularly bonding points.

[0033] The fact that the comparative nonwoven fabric is manufactured under the same conditions means, within the framework of the present invention, that the comparative nonwoven fabric is manufactured under the same conditions as the nonwoven fabric of the present invention, using the same equipment as the nonwoven fabric of the present invention. In this case, the comparative nonwoven fabric has the same number of nonwoven layers as the nonwoven fabric of the present invention, and all nonwoven layers of the comparative nonwoven fabric are manufactured under the same conditions as the nonwoven layers of the nonwoven fabric of the present invention. In particular, the preliminary and final immobilization treatments, and the introduction of the embossed pattern consisting of bonded areas in the case of the comparative nonwoven fabric are carried out in the same manner as in the nonwoven fabric of the present invention. In this case, the measurement of the tensile strength or specific tensile strength of the comparative nonwoven fabric and the nonwoven fabric of the present invention is carried out as previously described. The present invention has recognized that nonwoven fabrics according to the present invention made of multi-component filaments, particularly two-component filaments, have considerable advantages with respect to tensile strength or specific tensile strength in the MD direction and / or CD direction compared to nonwoven fabrics made of one-component filaments made of a first polypropylene component or a second polypropylene component, but otherwise manufactured under the same conditions. Due to the similarity of the polypropylene components or base polypropylene according to the present invention in relation to at least some properties, a two-component filament is produced, so to speak, that is similar to a one-component filament in relation to at least certain properties, but the strength value or specific strength value of the resulting nonwoven fabric is surprisingly much higher than that of a comparative nonwoven fabric made of a one-component filament.

[0034] The total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric is at least 200 J / m². 2 , in particular, at least 300 J / m 2 Preferably at least 400 J / m 2 Particularly preferably at least 500 J / m 2 This falls within the scope of the present invention. The TEA values ​​and total TEA values ​​described herein and below particularly apply to nonwoven fabrics that have been final-fixed, especially thermally fixed, and preferably have an embossed pattern consisting of bonding sites, and especially bonding points.

[0035] Nonwoven fabric, 20g / m 2 From 110g / m 2up to, especially 25 g / m 2 to 85 g / m 2 up to, preferably 30 g / m 2 to 75 g / m 2 having a basis weight of up to, and in this case, the total TEA value (MD - TEA + CD - TEA) of the non - woven fabric is at least 1500 J / m 2 , especially at least 2500 J / m 2 , particularly at least 4000 J / m 2 , preferably at least 5000 J / m 2 , particularly preferably at least 6000 J / m 2 , especially particularly preferably at least 8000 J / m 2 , for example at least 10000 J / m 2 is very preferably.

[0036] One further or alternative preferred embodiment of the non - woven fabric according to the present invention is that the non - woven fabric has a basis weight of from 1 g / m 2 to 20 g / m 2 up to, especially from 2 g / m 2 to 19 g / m 2 , preferably from 5 g / m 2 to 18 g / m 2 having a basis weight of up to, and in this case, the total TEA value (MD - TEA + CD - TEA) of the non - woven fabric is at least 200 J / m 2 , especially at least 300 J / m 2 , particularly at least 400 J / m 2 , preferably at least 500 J / m 2 characterized in that.

[0037] Within the framework of this invention, the TEA value specifically refers to the tensile energy absorption (TEA) of the nonwoven fabric under tensile load. Within the framework of this invention, the TEA value in the MD direction or CD direction is specifically determined from the area under the force-extension curve at the maximum force (y value) and maximum force elongation (x value), respectively, where the creation of the force-extension curve in the MD direction or CD direction is performed on an untreated, dry nonwoven fabric sample (measurement sample), in particular, similar to the test standard DIN EN ISO9073-3:2023-09. Within the framework of this invention, in particular, in each case, at least five sufficiently long nonwoven fabric samples, each 50 mm wide, are taken at equal intervals across the roller width or material cross-sectional width in the MD and CD directions. These samples are fixed between two fixtures spaced 100 mm apart, so that the inspection / measurement length of the sample is 100 mm. Next, these nonwoven fabric samples are stretched taut using a tensile machine at a feed rate of 100 mm / min to a preload force of 0.5 N. Then, in this state, the measurement is reset to zero, and the actual measurement is started. At this time, the tensile machine is operated at a feed rate or tensile speed of 200 mm / min. The TEA values ​​in the MD and CD directions are determined, in particular, as the arithmetic mean of the measured samples. The total TEA value is expressed in units of J / m 2 MD-TEA value and unit J / m 2 It is obtained from the sum of the CD-TEA values.

[0038] The nonwoven fabric has a weight of 20 g / m². 2 From 110g / m 2 Up to, especially 25g / m 2 From 85g / m 2 Up to, preferably 30 g / m 2 From 75g / m 2 The basis weight is up to a certain amount, and in this case, the total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric is between 1500 and 15000 J / m². 2 Up to, in particular, 2500 to 13000 J / m³ 2 The MD-TEA value of the nonwoven fabric is up to 950 to 8500 J / m². 2Up to, in particular, 1500 to 8000 J / m³ 2 Up to and / or the CD-TEA value of the nonwoven fabric is 500 to 6000 J / m 2 Up to, in particular, 1500 to 5500 J / m³ 2 The fact that it is up to this point is within the scope of the present invention.

[0039] According to yet another preferred or alternative embodiment, the nonwoven fabric is 1 g / m² 2 and 20g / m 2 Between these two, in particular, 2g / m 2 From 19g / m 2 Up to, preferably 5 g / m 2 From 18g / m 2 The basis weight is up to a certain amount, and in this case, the total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric is 200 to 600 J / m². 2 Up to, in particular, 250 to 550 J / m 2 The MD-TEA value of the nonwoven fabric is 125 to 400 J / m². 2 Up to, in particular, 140 to 350 J / m³ 2 The CD-TEA value of the nonwoven fabric is 80 to 250 J / m². 2 Up to, in particular, 90 to 240 J / m³ 2 That is the end.

[0040] One particularly preferred embodiment of the present invention is characterized in that the total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric is more than 5%, particularly more than 10%, preferably more than 15%, especially more than 20%, and most preferably more than 25%, higher than the corresponding total TEA value (ME-TEA + CD-TEA) of a comparative nonwoven fabric manufactured from a one-component filament made of a first or second polypropylene component under otherwise the same conditions. Within the framework of this embodiment, the same requirements already described above apply to the comparative nonwoven fabric, particularly with respect to the apparatus for manufacturing the comparative nonwoven fabric and the conditions for manufacturing the comparative nonwoven fabric. It is even more preferable that the total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric is 30% higher, particularly 40% higher, preferably 50% higher, especially 60% higher, and most preferably 70% higher, for example 80% higher, than the corresponding total TEA value (MD-TEA + CD-TEA) of a comparative nonwoven fabric manufactured from a single-component filament made of a first polypropylene component or a second polypropylene component under otherwise the same conditions.

[0041] The nonwoven fabric has a weight of 20 g / m². 2 From 110g / m 2 Up to, especially 25g / m 2 From 85g / m 2 Up to, preferably 30 g / m 2 From 75g / m 2 The nonwoven fabric has a basis weight up to a certain amount, and in this case, it is preferable that the total TEA value of the nonwoven fabric (MD-TEA + CD-TEA) is 40% higher, preferably 80% higher, particularly preferably 100% higher, even more preferably 200% higher, and especially most preferably 300% higher than the corresponding total TEA value (ME-TEA + CD-TEA) of a comparative nonwoven fabric manufactured from a one-component filament made of a first polypropylene component or a second polypropylene component under otherwise the same conditions.

[0042] According to yet another or alternative preferred embodiment of the nonwoven fabric according to the present invention, the nonwoven fabric is 1 g / m² 2 and 20g / m 2 Between these two, in particular, 2g / m 2From 19g / m 2 Up to, preferably 5 g / m 2 From 18g / m 2 The nonwoven fabric has a basis weight up to a certain amount, and in this case, the total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric is 15% or more, particularly 25% or more, preferably 30% or more, and especially preferably 50% or more, higher than the corresponding total TEA value (ME-TEA + CD-TEA) of a comparative nonwoven fabric manufactured from a one-component filament made of a first polypropylene component or a second polypropylene component under otherwise the same conditions.

[0043] It is within the scope of the present invention that the filament has a fineness of less than 2.3 den, particularly less than 2.1 den, preferably less than 1.9 den, and especially preferably between 1.0 and 2.2 den, most preferably between 1.2 and 2.0 den, for example between 1.4 and 1.8 den.

[0044] To address the above technical challenges, the present invention further provides a method for producing the nonwoven fabric described above, comprising generating filaments using at least one spinning apparatus, particularly at least one spinneret, and depositing them on at least one deposition apparatus, particularly on at least one deposition screen belt, to form a nonwoven fabric.

[0045] It is within the scope of the present invention to manufacture a nonwoven fabric, or a nonwoven layer of a nonwoven fabric, according to the present invention, by a spunbond method. A preferred spunbond method for a nonwoven fabric or nonwoven layer according to the present invention is described below. In this method, the filaments or endless filaments of the nonwoven fabric or nonwoven layer are spun using a spinning apparatus configured as a spinneret, and then cooled in a cooling device equipped with a cooling chamber. It is within the scope of the present invention that a monomer suction device is placed between the spinneret and the cooling device to remove unwanted gases generated during the spinning process from the apparatus. After passing through the cooling device, the filaments are, for purpose, passed through a stretching device for stretching the endless filaments. It is recommended that the stretching device be equipped with an intermediate channel, which connects the cooling device and the stretching shaft of the stretching device. According to a particularly preferred embodiment of the present invention, a coupling machine comprising a cooling device and a stretching device, or a coupling machine comprising a cooling device, an intermediate channel and a stretching shaft, is configured as a closed coupling machine, and no further air is supplied to this coupling machine from the outside, other than the supply of cooling air into the cooling device.

[0046] Preferably, in the direction of filament flow, the stretcher is connected to at least one diffuser through which the continuous filament is guided. Purposefully, the continuous filament is deposited on a deposition facility after passing through at least one diffuser, which is configured in particular as a deposition screen belt. It is preferable that the deposition screen belt be an endlessly circulating deposition screen belt. Purposefully, the deposition screen belt is designed to be air permeable so as to allow the suction of process air from below through the deposition screen belt. Preferably, at least one suction device is provided for the suction of process air below the deposition screen belt. If the nonwoven fabric according to the present invention has at least two, and in particular at least three, nonwoven layers, then the apparatus for producing the corresponding nonwoven fabric has, in particular, correspondingly, at least two, and in particular at least three spinnerets or spinning beams (each equipped with the aforementioned components located in or below the spinneret area), and the apparatus for producing the nonwoven layers is, in particular, located on just one deposition apparatus, in particular on just one deposition screen belt, on which each nonwoven layer of the nonwoven fabric is deposited in stacks and then, in particular, combined to form a nonwoven laminate.

[0047] The nonwoven fabric is final-fixed using at least one immobilization device, particularly at least one calender roller, and preferably, the temperature of the at least one immobilization device, particularly the at least one calender roller, in particular, is between 120°C and 180°C, especially between 130°C and 175°C, preferably between 140°C and 170°C, and very preferably between 145°C and 165°C, which is within the scope of the present invention. According to a particularly preferred embodiment of the method according to the present invention, the nonwoven fabric is final-fixed using an immobilization device configured as a calender with at least two calender rollers, and for purposeful purposes, the surface temperature of at least one calender roller of the calender, particularly both calender rollers of the calender, is between 120°C and 180°C, particularly between 130°C and 175°C, preferably between 140°C and 170°C, and very preferably between 145°C and 165°C. In a very preferred embodiment, the immobilization equipment, in particular the calender, has at least one calender roller (gravure roller) for generating an embossed pattern consisting of joints, in particular joint points, wherein the calender roller has, in particular, a complementary embossed pattern consisting of embossed elements on its outer surface. More preferably, the immobilization equipment, in particular the calender, has at least one calender roller (S-roller) having a smooth outer surface.

[0048] The complementary embossing pattern of at least one calendar roller for introducing an embossed pattern consisting of bonding sites or bonding points into a nonwoven fabric has embossed surfaces of 5% to 35%, particularly 10% to 25%, and / or 10 Fig / cm². 2 From 100 Fig / cm 2 Up to, in particular, 25 Fig / cm 2 From 75 Fig / cm 2 Having a graphic density up to this point is within the scope of the present invention.

[0049] It is within the scope of the present invention that the temperature of at least one immobilization device, particularly the temperature of at least one calender roller, especially the surface temperature, is at least 1°C, particularly at least 2°C, preferably at least 3°C, especially preferably at least 4°C, and most preferably at least 5°C lower than the melting point of the base polypropylene of the second polypropylene component and / or the base polypropylene of the first polypropylene component. In particular, this description relates to both calender rollers of an immobilization device configured as a calender.

[0050] The speed of the deposition equipment, particularly the speed of the deposition screen belt, is within the scope of the method of the present invention, ranging from 30 m / min to 1100 m / min, and especially from 40 m / min to 1000 m / min. The nonwoven fabric is 20 g / m 2 From 110g / m 2 Up to, especially 25g / m 2 From 85g / m 2 Up to, preferably 30 g / m 2 From 75g / m 2 It is within the scope of the present invention that the basis weight is up to 1 g / m², and in this case, the speed of the loading equipment, in particular the speed of the loading screen belt, is from 30 m / min to 120 m / min, and especially from 40 m / min to 110 m / min. Furthermore or alternatively, the nonwoven fabric has a basis weight of 1 g / m². 2 and 20g / m 2 Between these two, in particular, 2g / m 2 From 19g / m 2 Up to, preferably 5 g / m 2 From 18g / m 2 The basis weight is up to a certain amount, and in this case, the speed of the loading equipment, especially the speed of the loading screen belt, is between 250 and 1200 m / min, and particularly between 500 and 1100 m / min, which is within the scope of the present invention. [Examples]

[0051] Example 1 according to the present invention: In a first embodiment of the present invention, a single-layer nonwoven fabric was produced from a two-component filament having a concentric or symmetrical core-sheath structure. The core component of the two-component filament was formed from a first polypropylene component consisting of or essentially derived from a first base polypropylene. For the sheath component, a second polypropylene component consisting of or essentially derived from a second base polypropylene was used. The two-component filament was produced as an endless filament according to the spunbond method in the apparatus described above, or according to the previously described method for the production of a nonwoven fabric or spunbond nonwoven fabric. The two-component filament was produced with a filament fineness of 1.6 den. The nonwoven fabric was prepared with a surface temperature of 155°C on the gravure roller of a calendar and 150°C on the S roller, as detailed in Fig. 49.9 / cm². 2 The oval-shaped immobilized ridges of a certain density were used for final immobilization with a calender at an embossed area of ​​18.1%. As the first polypropylene component or first base polypropylene, homo-polypropylene having a melt flow rate of 15 g / 10 min was used. The first polypropylene component or first base polypropylene formed the core of the two-component filament of the endless filament of the first embodiment according to the present invention. Here, for the first polypropylene component or first base polypropylene, homo-polypropylene "Total MR 2002" was used. This is a metallocene-polypropylene polymerized using a metallocene catalyst. As the second polypropylene component or second base polypropylene, homo-polypropylene having a melt flow rate (MFR) of 25 g / 10 min was used. The second polypropylene component or second base polypropylene formed the sheath of the two-component filament having a core-sheath structure. Here, for the second polypropylene component or second base polypropylene, homo-polypropylene "Total MR 2001" was used. This is a metallocene-polypropylene polymerized using a metallocene catalyst.

[0052] The ratio of the mass of the first polypropylene component to the mass of the second polypropylene component was 80:20. The loading speed or loading screen belt speed was 62 m / min. The basis weight of the resulting nonwoven fabric was 66 g / m². 2 The difference in melting points between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component was 0°C or approximately 0°C. Both polypropylenes have a melting point of 151°C. The specific tensile strength of the nonwoven fabric in the MD direction was 1 g / m². 2 The strength is 4.9 N / 5 cm, and the specific tensile strength of the nonwoven fabric in the CD direction is 1 g / m 2 The TEA value was 3.3 N / 5 cm. The total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric was 6247 J / m². 2 The MD-TEA value of the nonwoven fabric was 3824 J / m². 2 The CD-TEA value of the nonwoven fabric is 2423 J / m². 2 That was the case.

[0053] Nonwoven fabric 1 for comparison: Comparative nonwoven fabric 1 was manufactured from a one-component filament made of the first polypropylene component described earlier in the first embodiment of the present invention, under the same conditions as the first embodiment of the present invention. The resulting comparative nonwoven fabric 1 was identical to the nonwoven fabric described earlier in the first embodiment of the present invention in terms of its filament fineness and basis weight. Comparative nonwoven fabric 1 had a basis weight of 1 g / m². 2 Specific tensile strength in the MD direction of 2.6 N / 5 cm and 1 g / m² 2 It had a specific tensile strength in the CD direction of 1.8 N / 5 cm. The comparative nonwoven fabric had a specific tensile strength of 1639 J / m². 2 It has a total TEA value of 901 J / m³, in which case the MD-TEA value is 901 J / m³. 2 The CD-TEA value is 738 J / m³. 2As a result, the specific tensile strength in the MD and CD directions of the nonwoven fabric according to the first embodiment of the present invention is more than 80% higher than the corresponding tensile strength of a comparative nonwoven fabric manufactured under otherwise identical conditions from a single-component filament made of the first polypropylene component. Furthermore, the total TEA value of the nonwoven fabric according to the present invention is more than 280% higher than the corresponding total TEA value of a comparative nonwoven fabric manufactured under otherwise identical conditions from a single-component filament made of the first polypropylene component.

[0054] Example 2 of the present invention: In a second embodiment of the present invention, a nonwoven fabric made of two-component filaments having a concentric or symmetrical core-sheath structure was produced. This nonwoven fabric was produced as a three-layer nonwoven fabric having three identical nonwoven layers. The two-component filaments were produced as endless filaments in the apparatus described above according to the spunbond method, or according to the previously described method for the production of nonwoven fabrics or spunbond nonwoven fabrics, using three spinnerets or spinning beams connected in series. These spinnerets or spinning beams each have components placed beneath them on a single deposition screen belt. The core component of the two-component filament was formed from a first polypropylene component consisting of or essentially derived from a first base polypropylene. For the sheath component, a second polypropylene component consisting of or essentially derived from a second base polypropylene was used. The two-component filaments were produced with filament finenesses ranging from 1.4 to 1.5 den. This nonwoven fabric was produced using a calender, with the surface temperature of the gravure roller of the calender set to 160°C and the surface temperature of the S roller set to 150°C, resulting in a yield of 49.9 Fig / cm². 2The filaments were finalized using an 18.1% embossed surface with circular fixed ridges at a density of . As the first polypropylene component or first base polypropylene, homo-polypropylene having a melt flow rate of 25 g / 10 min was used. The first polypropylene component or first base polypropylene formed the core of the two-component filament of the second embodiment of the present invention. Here, for the first polypropylene component or first base polypropylene, homo-polypropylene "Borealis HG475FB" was used. This is Ziegler-Natta propylene polymerized using a Ziegler-Natta catalyst. As the second polypropylene component or second base polypropylene, homo-polypropylene having a melt flow rate (MFR) of 35 g / 10 min was used. The second polypropylene component or second base polypropylene formed the sheath of the two-component filament having a core-sheath structure. Here, for the second polypropylene component or second base polypropylene, homo-polypropylene "Exxon 3155" was used. This is Ziegler-Natta polypropylene polymerized using a Ziegler-Natta catalyst. The ratio of the mass of the first polypropylene component to the mass of the second polypropylene component was 70:30. The loading speed of the loading equipment or loading screen belt was 620 m / min. The basis weight of the resulting nonwoven fabric was 13 g / m². 2 The difference in melting points between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component was 0°C or approximately 0°C. Both polypropylenes have a melting point of 161°C. The specific tensile strength of the nonwoven fabric in the MD direction was 1 g / m². 2 The strength is 2.8 N / cm, and the specific tensile strength of the nonwoven fabric in the CD direction is 1 g / m 2 The TEA value was 1.5 N / 5 cm. The total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric was 513 J / m². 2 The MD-TEA value of the nonwoven fabric was 311 J / m². 2 The CD-TEA value of the nonwoven fabric is 202 J / m 2 That was the case.

[0055] Nonwoven fabric 2 for comparison: Regarding the second embodiment of the present invention, comparative nonwoven fabric 2 was manufactured from a one-component filament made of the first polypropylene component described above, under the same conditions as the second embodiment of the present invention. The resulting comparative nonwoven fabric 2 was the same as the nonwoven fabric described above in the second embodiment of the present invention in terms of its fineness and basis weight. Comparative nonwoven fabric 2 was 1 g / m² 2 Specific tensile strength in the MD direction of 2.6 N / 5 cm and 1 g / m² 2 It had a specific tensile strength in the CD direction of 1.3 N / 5 cm. The comparative nonwoven fabric had a specific tensile strength of 393 J / m². 2 It has a total TEA value of 246 J / m³, in which case the MD-TEA value is 246 J / m³. 2 The CD-TEA value is 147 J / m³. 2 Therefore, the specific tensile strength of the nonwoven fabric according to the second embodiment of the present invention is more than 7% higher in the MD direction and more than 15% higher in the CD direction than the corresponding tensile strength of a comparative nonwoven fabric manufactured from a single-component filament made of the first polypropylene component under otherwise the same conditions. Furthermore, the total TEA value of the nonwoven fabric according to the present invention (the second embodiment of the present invention) is more than 30% higher than the corresponding total TEA value of a comparative nonwoven fabric manufactured from a single-component filament made of the first polypropylene component under otherwise the same conditions.

[0056] The present invention is based on the finding that nonwoven fabrics made of multi-component filaments, particularly two-component filaments, according to the present invention feature remarkably high strength or tensile strength compared to nonwoven fabrics made from Praktis by known means. Due to the similarity between the base polypropylene of the first polypropylene component and the base polypropylene of the second polypropylene component with respect to at least some properties—particularly with respect to melting point and polymerization catalyst—and the properties resulting therefrom, a multi-component or two-component filament is provided, so to speak—at least with respect to certain properties—that is like a one-component filament, in which case the properties of these filaments can be controlled more precisely than with a one-component filament. This results in a nonwoven fabric having very high tensile strength values ​​in the MD direction and / or CD direction, which reliably meets all requirements for strength, particularly tensile strength. Furthermore, it should be emphasized that the measures according to the present invention are less complicated, and that the nonwoven fabric and the method according to the present invention are very economical.

[0057] The present invention will be described in more detail below, based on drawings showing only one embodiment. [Brief explanation of the drawing]

[0058] [Figure 1] A schematic vertical cross-sectional view is shown of an apparatus for manufacturing a nonwoven fabric or a nonwoven fabric layer of a nonwoven fabric according to the present invention. [Figure 2] A schematic cross-sectional view of a nonwoven fabric filament according to the present invention having a concentric or symmetrical core-sheath structure is shown.

[0059] Figure 1 shows an apparatus for manufacturing a nonwoven fabric 8 or a nonwoven fabric layer of the nonwoven fabric 8 according to the present invention. If the nonwoven fabric has at least two, particularly at least three, or especially three nonwoven fabric layers according to one of the preferred embodiments, then at least two, particularly at least three, or three spinnerets 6 or spinning beams are connected in a continuous manner in the transport direction F or the machine direction (MD) of a deposition screen belt 7, each equipped with components positioned beneath them, and these three nonwoven fabric layers are, in particular, deposited in stacks on one deposition screen belt 7, preferably combined to form a single laminate.

[0060] The apparatus preferably and in this embodiment comprises a spinning apparatus or spinning beam in the form of a spinneret 6 for spinning a filament or endless filament 1 for a nonwoven fabric 8 or a nonwoven layer of the nonwoven fabric 8. The continuous filament 1 spun from the spinneret 6 is introduced, in particular and in this embodiment, into a cooling apparatus 12 having a cooling chamber 13. In particular and in this embodiment, two opposing air supply cabins 14, 15 are arranged on top of each other on two opposing sides of the cooling chamber 13. From these top-and-bottom air supply cabins 14, 15, air at different temperatures is introduced into the cooling chamber 13 for purpose. Preferably and in this embodiment, a monomer suction apparatus 16 is located between the spinneret 6 and the cooling apparatus 12. This monomer suction apparatus 16 can be used to remove interfering gases generated during the spinning process from the apparatus.

[0061] In the recommended and embodiment, a stretcher 17 for stretching the endless filament 1 is positioned after the cooling device 12 in the filament flow direction. For the purpose and embodiment, the stretcher 17 includes an intermediate channel 18 which connects the cooling device 12 to the stretcher shaft 19 of the stretcher 17. In particular and embodiment, the coupling machine consisting of the cooling device 12 and the stretcher 17, or the coupling machine consisting of the cooling device 12, the intermediate channel 18 and the stretcher shaft 19, is configured as a closed coupling machine, and no further external air is supplied to this coupling machine other than the supply of cooling air into the cooling device 12.

[0062] In purpose and in this embodiment, in the direction of filament flow, a diffuser 20 is connected to the stretching device 17, through which the endless filament 1 is guided. After passing through the diffuser 20, the endless filament 1 is deposited, in particular and in this embodiment, on a deposition facility configured as a deposition screen belt 7 in a deposition region. The deposition screen belt 7 is configured, in purpose and in this embodiment, as an endlessly circulating deposition screen belt 7. It is within the framework of the present invention that the deposition screen belt 7 is air permeable, so as to allow the suction of process air from below through the deposition screen belt 7. In particular and in this embodiment, the apparatus includes a fixing facility configured as a calender 11 for the final fixing of the nonwoven fabric 8 after the deposition region of the endless filament 1 in the nonwoven fabric transport direction F or the machine direction MD. Preferably and in this embodiment, the calender 11 comprises two calender rollers 9, 10. One of the calendar rollers 9 and 10, also called a gravure roller, can have a complementary embossed pattern consisting of embossed elements on its outer surface, thereby introducing an embossed pattern consisting of bonding points, particularly bonding locations, into the nonwoven fabric 8. In particular, the other calendar roller, also called an S roller, can have a smooth outer surface in a preferred embodiment. This is not shown in detail in Figure 1.

[0063] Figure 2 shows a cross-section of an endless filament 1 having a concentric or symmetrical core-sheath structure. This is a two-component filament 1 having a first polypropylene component 2, which preferably and in this embodiment consists of or is essentially made from a first base polypropylene and forms the core 4 of the two-component filament 1. Furthermore, the two-component filament 1 includes a second polypropylene component 3, which, in particular and in this embodiment, consists of or is essentially made from a second base polypropylene and forms the sheath 5 of the two-component filament 1. The base polypropylene of the first polypropylene component 2 and the base polypropylene of the second polypropylene component 3 may, in particular and in this embodiment, be produced using a metallocene catalyst and have the same or essentially the same melting point, in which case, for the purpose and in this embodiment, the base polypropylene of the first polypropylene component 2 and the base polypropylene of the second polypropylene component 3 are different polypropylenes. The ratio of the mass of the first polypropylene component 2 forming the core 4 of the two-component filament 1 to the mass of the second polypropylene component 3 forming the sheath 5 of the two-component filament 1 may, for the purpose and in this embodiment, be approximately 75:25.

Claims

1. In a nonwoven fabric made of endless filaments (1), the filaments (1) are multi-component filaments, particularly two-component filaments, and the nonwoven fabric comprises at least one first polypropylene component (2) containing a base polypropylene and at least one second polypropylene component (3) containing a base polypropylene, The difference in melting points between the base polypropylene of the first polypropylene component (2) and the base polypropylene of the second polypropylene component (3) is less than 5°C, particularly less than 4°C, preferably less than 3°C, especially preferably less than 2°C, and most preferably less than 1°C. The base polypropylene of the first polypropylene component (2) and the base polypropylene of the second polypropylene component (3) are polymerized using a catalyst from the same catalyst species, preferably using a metallocene catalyst or a Ziegler-Natta catalyst, respectively. Nonwoven fabric.

2. The nonwoven fabric according to claim 1, wherein the filament (1) is a multi-component filament or a two-component filament having a core-sheath structure, particularly a concentric or symmetrical core-sheath structure, in which case, in particular, the first polypropylene component (2) forms the core (4) of the filament (1) and the second polypropylene component (3) forms the sheath (5) of the filament (1).

3. The nonwoven fabric according to claim 1 or 2, wherein the first polypropylene component (2) and / or the second polypropylene component (3) each contain base polypropylene in a proportion of at least 70% by weight, particularly at least 80% by weight, preferably at least 85% by weight, especially preferably at least 90% by weight, and most preferably at least 92% by weight.

4. The nonwoven fabric according to any one of claims 1 to 3, wherein the first polypropylene component (2) and / or the second polypropylene component (3) consist of or are essentially made of their respective base polypropylenes.

5. The nonwoven fabric according to any one of claims 1 to 4, wherein the first polypropylene component (2) and / or the second polypropylene component (3) is a mixture or blend of each base polypropylene with at least one additive.

6. The nonwoven fabric according to any one of claims 1 to 5, wherein different polypropylenes are used as the base polypropylene of the first polypropylene component (2) and the base polypropylene of the second polypropylene component (3).

7. The nonwoven fabric according to any one of claims 1 to 5, wherein the same polypropylene is used as the base polypropylene of the first polypropylene component (2) and as the base polypropylene of the second polypropylene component (3), and therein, at least one polypropylene component (2, 3), in particular at least the second polypropylene component (3), is a mixture or blend of the base polypropylene and at least one additive.

8. The proportion of the at least one additive in the first polypropylene component (2) and / or the second polypropylene component (3) is 0.1 to 30.0% by weight, particularly 0.2 to 20.0% by weight, preferably 0.5 to 15.0% by weight, especially preferably 1.0 to 10.0% by weight, most preferably 1.5 to 9.0% by weight, even more preferably 2.0 to 8.0% by weight, for example 3.0 to 6.0% by weight, wherein the at least one additive is, for the purposes, additive polypropylene, as described in any one of claims 5 to 7.

9. The nonwoven fabric according to any one of claims 1 to 8, wherein the base polypropylene of the first polypropylene component (2) and the base polypropylene of the second polypropylene component (3) have the same or essentially the same melting point.

10. The nonwoven fabric according to any one of claims 1 to 9, wherein the melt flow rate (MFR) of the second polypropylene component (3) is higher than the melt flow rate (MFR) of the first polypropylene component (2), and in this case, the ratio of the melt flow rate (MFR) of the second polypropylene component (3) to the melt flow rate (MFR) of the first polypropylene component (2) is particularly between 1.02 and 10, especially between 1.05 and 8, preferably between 1.1 and 6, particularly preferably between 1.2 and 3, and most preferably between 1.3 and 2.2, for example between 1.35 and 2.

0.

11. The nonwoven fabric according to any one of claims 1 to 10, wherein the ratio of the mass of the first polypropylene component (2) to the mass of the second polypropylene component (3) is from 95:5 to 50:50, particularly from 90:10 to 55:45, preferably from 85:15 to 60:40, especially preferably from 85:15 to 65:35, and most preferably from 85:15 to 70:30, for example from 80:20 to 75:

25.

12. The nonwoven fabric according to any one of claims 1 to 11, wherein the base polypropylene of the first polypropylene component (2) and / or the base polypropylene of the second polypropylene component (3) and / or at least one additive polypropylene is homo-polypropylene or polypropylene copolymer.

13. The nonwoven fabric (8) is final fixed, in particular thermally fixed, and in particular has an embossed pattern consisting of bonding sites, in particular bonding points, according to any one of claims 1 to 12.

14. The non-woven fabric (8) has a basis weight of from 20 g / m ２ to 110 g / m ２ and especially from 25 g / m ２ to 85 g / m ２ and preferably from 30 g / m ２ to 75 g / m ２ and, preferably, the specific tensile strength of the non-woven fabric (8) in the MD direction is from 2.5 to 7.2 N / 5 cm per 1 g / m ２ and especially from 3.0 to 7.0 N / 5 cm per 1 g / m ２ and preferably from 3.2 to 6.8 N / 5 cm per 1 g / m ２ and particularly preferably from 3.4 to 6.7 N / 5 cm per 1 g / m ２ and especially preferably from 3.5 to 6.5 N / 5 cm per 1 g / m ２ and / or preferably, the specific tensile strength of the non-woven fabric (8) in the CD direction is from 2.0 to 4.0 N / 5 cm per 1 g / m ２ and especially from 2.1 to 3.8 N / 5 cm per 1 g / m ２ and preferably from 2.2 to 3.7 N / 5 cm per 1 g / m ２ and particularly preferably from 2.3 to 3.6 N / 5 cm per 1 g / m ２ ２ The non-woven fabric according to any one of claims 1 to 13.

15. Nonwoven fabric (8) is 1 g / m ２ and 20 g / m ２ Between these two, in particular, 2 g / m ２ From 19 g / m ２ Up to, preferably 5 g / m ２ From 18 g / m ２ The basis weight is up to a certain amount, and in this case, preferably the specific tensile strength of the nonwoven fabric (8) in the MD direction is 1 g / m ２ From 1.5 to 4.5 N / 5 cm, especially 1 g / m ２ The N / 5cm range is 1.7 to 4.0 N / m², preferably 1 g / m². ２ The load capacity is 1.8 to 3.8 N / 5 cm, particularly preferably 1 g / m². ２ The N / 5cm range is 2.0 to 3.5 N per 5cm, with a particularly preferred N / 5cm. ２ The specific tensile strength of the nonwoven fabric (8) in the CD direction is 2.0 to 3.0 N / 5 cm, and / or preferably 1 g / m ２ From 1.0 to 2.5 N / 5 cm, especially 1 g / m ２ The N / 5cm range is 1.1 to 2.0 N / m², preferably 1 g / m². ２ The N / 5cm range is 1.2 to 1.9 N / m², with a particularly preferred N / m². ２ A nonwoven fabric according to any one of claims 1 to 14, wherein the N / 5cm is 1.2 to 1.8 N per square meter.

16. The nonwoven fabric (8) has an embossed pattern consisting of bonding sites, particularly bonding points, wherein the proportion of pore volume in the region of the bonding sites is from 1.0% to 12.0%, particularly from 1.5% to 10.0%, preferably from 2.0% to 7.0%, and most preferably from 2.5% to 6.5%, according to any one of claims 1 to 15.

17. The nonwoven fabric according to any one of claims 1 to 16, wherein the tensile strength and / or specific tensile strength of the nonwoven fabric (8) in the MD direction and / or CD direction is more than 4%, particularly more than 6%, especially more than 10%, preferably more than 15%, and most preferably more than 20% higher than the corresponding tensile strength and / or specific tensile strength of a comparative nonwoven fabric manufactured from a one-component filament made of a first polypropylene component (2) or a second polypropylene component (3) under otherwise the same conditions.

18. The total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric (8) is at least 200 J / m ２ In particular, at least 300 J / m ２ Preferably at least 400 J / m ２ Particularly preferably at least 500 J / m ２ The nonwoven fabric according to any one of claims 1 to 17.

19. The nonwoven fabric according to any one of claims 1 to 18, wherein the total TEA value (MD-TEA + CD-TEA) of the nonwoven fabric (8) is more than 5%, particularly more than 10%, preferably more than 15%, especially preferably more than 20%, and most preferably more than 25%, higher than the corresponding total TEA value (MD-TEA + CD-TEA) of a comparative nonwoven fabric manufactured from a one-component filament made of a first polypropylene component (2) or a second polypropylene component (3) under otherwise the same conditions.

20. The nonwoven fabric according to any one of claims 1 to 19, wherein the filaments have a fineness of less than 2.3 den, particularly less than 2.1 den, preferably less than 1.9 den, and especially preferably from 1.0 to 2.2 den, most preferably from 1.2 to 2.0 den, for example from 1.4 to 1.8 den.

21. A method for producing a nonwoven fabric according to any one of claims 1 to 20, wherein a filament (1) is produced using at least one spinning apparatus, in particular at least one spinneret (6), and then deposited on at least one deposition apparatus, in particular at least one deposition screen belt (7) to form a nonwoven fabric (8).

22. The method according to claim 21, wherein the nonwoven fabric (8) is final-fixed using at least one fixation device, in particular at least one calender roller (9), wherein the temperature of the at least one fixation device, in particular at least one calender roller (9), in particular the surface temperature, is preferably between 120°C and 180°C, more particularly between 130°C and 175°C, preferably between 140°C and 170°C, and very preferably between 145°C and 165°C.

23. The method according to claim 22, wherein the temperature of at least one immobilization device, in particular at least one calendar roller (9), in particular the surface temperature, is at least 1°C, particularly at least 2°C, preferably at least 3°C, especially preferably at least 4°C, and most preferably at least 5°C lower than the melting point of the base polypropylene of the second polypropylene component (3) and / or the base polypropylene of the first polypropylene component (2).

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