Layered Nonwoven Fabric and Method of Producing a Layered Nonwoven Fabric

Abstract

LAYERED NONWOVEN FABRIC AND METHOD OF PRODUCING A LAYERED NONWOVEN FABRIC. Layered nonwoven fabric containing: - a first layer (T) of filaments, which contains continuous filaments containing a first carrier polymer (A1) and a first linker polymer (B1), which forms at least part of the surface of said continuous filaments and which has a melting temperature at least 5°C lower than that of the first carrier polymer (A1), wherein the first layer (T) of filaments contains link points in a spaced arrangement, wherein the link points interconnect the filaments and are formed by the first linker polymer (B1);- a second layer (M) of filaments, containing filaments containing a carrier material, whose stiffness is lower than the stiffness of the first carrier polymer (A1), and a second linking polymer (B2), which has a melting temperature at least 5°C, preferably at least 10°C, lower than that of the carrier material and the first carrier polymer (A1), wherein the second layer (M) of filaments contains linking points in a spaced arrangement, wherein the linking points interconnect the filaments of the second layer (M) and are formed by the second linking polymer (B1).

Description

1 / 115 Layered Nonwoven Fabric and Method of Producing a Layered Nonwoven Fabric FIELD OF THE INVENTION

[001] The invention relates to a layered nonwoven fabric containing at least two layers of filaments, wherein the first layer of filaments contains continuous filaments containing the first carrier polymer and the first linker polymer, which forms at least part of the surface of these continuous filaments and has a melting temperature at least 5°C lower than that of the first carrier polymer, while the second layer of filaments contains spaced-arrangement linking points, wherein the linking points interconnect the filaments and are constituted by the first linker polymer. The result is a soft and bulky spunmelt-type nonwoven fabric with good recovery and abrasion resistance, suitable for various hygiene products, but also for filtration and other applications. The invention also encompasses the production process of this nonwoven fabric. BACKGROUND OF THE INVENTION

[002] It is possible to obtain volume in a nonwoven fabric using several known methods - namely by selecting suitable polymers, modifying the shape of the filament (various and using various methods of crimped or coiled filaments) and by the bonding method - either thermally (e.g., calendering with a suitable relief pattern, airflow spinning, ultrasonic bonding, etc.), mechanically (e.g., by wet spinning, Petition 870220076974, dated 08 / 26 / 2022, page 12 / 144 2 / 115 needle puncture etc.) or by combining various ligation methods.

[003] It generally applies that the more voluminous the material, the more open its structure, and the more advantageous bonding methods are those that do not compress the material. For example, bonding with calender rolls generally creates embossed embossing points that are substantially thinner than the surrounding areas (see, for example, patent application WO2017190717 or WO2017190717). From this perspective, it is, for example, more advantageous to bond using hot air, during which no compression occurs.

[004] The openness of a structure is mainly understood to mean the presence of free space between the filaments, denoted by the terms porosity or void volume. The greater the percentage of free space between the filaments, the greater the importance of the stiffness of the individual filaments. If the filaments are too flexible, the filament structure will not hold up, the filaments will bend, and the entire structure will collapse—the fabric thickness will be less than it could be. This is particularly noticeable in polyolefin-based filaments. The problem is solved, in particular, by using stiffer polymers (e.g., polyester), sufficiently stiff to maintain a very open textile structure and, additionally, to provide (particularly in air-laid materials obtained by airflow) the advantage of being able to recover their original volume after compression (i.e., recovery)—see, for example, the patent application. Petition 870220076974, dated 08 / 26 / 2022, page 13 / 144 3 / 115 WO2018059610 describing the use of crimped filaments with a cross-section called a crimp support (e.g., eccentric core / sheath) and, for example, our patent application PV 2018-647 (not yet published) which describes the use of filaments with a cross-section without crimp support (e.g., concentric core / sheath).

[005] Although stiffer and less flexible filaments allow for the creation of a more voluminous structure that is able to recover its initial volume after being compressed, their stiffness and lower flexibility negatively impact the overall softness, flexibility, and drapeability of the nonwoven fabric, which are key characteristics particularly for applications where the fabric is close to or in direct contact with the user's body (e.g., absorbent hygiene products).

[006] Efforts to solve this problem by means of filament layers with various properties are well known. Unlike carded nonwoven fabrics, standard production lines for spunmelt nonwoven fabrics do not allow the direct mixing of filaments from a single spinning beam. Individual filament layers placed on top of each other need to be subsequently joined, resulting in the combination of filaments with the same polymer base – see, for example, Reifenhauser and Fibertex Personal Care patent application EP2015153790 describing the combination of polyolefin-based layers with varying degrees of crimp. Petition 870220076974, dated 08 / 26 / 2022, page 14 / 144 4 / 115

[007] Another effort to achieve volume that is well known in the art is, for example, to utilize the different behaviors of stretched filaments when activated with hot air by means of a layer produced with a known shrinkage (e.g., PET / PE type two-component filaments), which is bonded through bonding points using a calender roll with a layer of less or no shrinkage (e.g., PP / PE). The structure is subsequently activated by means of thermal flow (e.g., hot air), the shrinkable layer contracts and forces the non-shrinkable layer to arch into pads between the bonding impressions – see, for example, patent application EP3192910 filed by Reifenhauser GmbH & Co. KG Maschinenfabrik. SUMMARY OF THE INVENTION

[008] The disadvantages and shortcomings of the existing state of the art are eliminated to a significant degree by a layered nonwoven fabric containing: - a first layer of filaments, which contains continuous filaments containing the first carrier polymer and the first linker polymer, which forms at least part of the surface of these continuous filaments and which has a melting temperature at least 5°C lower than that of the first carrier polymer, while the first layer of filaments contains link points in a spaced arrangement, where the link points interconnect the filaments and are constituted by the first linker polymer; Petition 870220076974, dated 08 / 26 / 2022, page 15 / 144 5 / 115 - a second layer of filaments, comprising filaments containing the carrier material, whose stiffness (generally tensile and / or flexural strength) is less than that of the first carrier polymer, and a second binder polymer that has a melting temperature of at least 5°C, or better yet, at least 10°C lower than that of the carrier material and the first carrier polymer, while the second layer of filaments contains spaced-arrangement bonding points, where the bonding points interconnect the filaments and comprise the second bonding polymer.

[009] The nonwoven fabric according to the invention does not have embossed markings. Preferably, the median spacing distance between adjacent bonding points in the first layer of filaments is less than or equal to 8 mm and / or the median spacing distance between adjacent bonding points in the second layer is less than or equal to 8 mm.

[010] Similarly, advantageously, the carrier material of the filaments in the second layer of filaments is a second carrier polymer whose tensile or flexural strength is at least 100 MPa lower than that of the first carrier polymer, while the second linking polymer forms at least part of the surface of these filaments and these second layer filaments are continuous filaments.

[011] Advantageously, the melting temperatures of the first linking polymer and the second linking polymer Petition 870220076974, dated 08 / 26 / 2022, page 16 / 144 6 / 115 differ by 0 to 5°C, or the first linking polymer is the same as the second linking polymer.

[012] Preferably, the first carrier polymer and / or the second carrier polymer are selected from a group comprising polyolefins, polyesters, polyamides and their copolymers and / or the first linker polymer and / or the second linker polymer are selected from a group comprising polyolefins, polyesters, polyamides and their copolymers.

[013] Advantageously, the first carrier polymer forms at least 55% by weight of the filaments in the first layer and / or the second carrier polymer forms less than 55% by weight of the filaments in the second layer (M).

[014] In a particularly advantageous configuration, the ratio of the weighted average density of the polymers in the continuous filaments of the first layer to the weighted average density of the polymers in the continuous filaments of the second layer is 1.0 to 1.5, preferably 1.1 to 1.3 and / or the ratio of the basic weight of the first layer to the basic weight of the second layer is 1.0 to 1.5, preferably 1.1 to 1.3.

[015] The shortcomings of the current state of technology are eliminated to a significant degree, in the same way, by the method of producing a layered nonwoven fabric, which includes the following steps: a) The first carrier polymer and the first linker polymer are melted, wherein the first linker polymer has a melting temperature at least 5°C lower than that of the first carrier polymer, and then fed Petition 870220076974, dated 08 / 26 / 2022, page 17 / 144 7 / 115 in the spinnerets of the first spinning beam, where continuous filaments are formed that have at least a portion of their surface comprising the first bonding polymer, after which such formed filaments are cooled and removed and subsequently deposited onto a roller belt, which creates the first layer of filaments; (b) the second layer of filaments containing the carrier material, which has lower stiffness than the first layer of filaments, is deposited on top of the first layer of filaments; and the second linking polymer has a melting temperature at least 5°C or, even better, at least 10°C lower than that of the carrier material and the first carrier polymer; c) After the effect of air heated to 100°C to 250°C, preferably to 120°C to 220°C, even better to 90°C to 140°C, more preferably to 110°C to 130°C, the first layer of filaments is formed by the creation of bonding points of the first bonding polymer between the filaments, and the second layer of filaments is formed by the creation of bonding points from the second bonding polymer.

[016] Advantageously in step b) the carrier material is melted, the second carrier polymer having a flexural and tensile strength of at least 100 MPa, better yet at least 200 MPa, better yet at least 300 MPa, better yet at least 400 MPa, advantageously at least 500 MPa, lower than the strength of the first carrier polymer and the second binder polymer, and are fed into the spinnerets of the second beam of Petition 870220076974, dated 08 / 26 / 2022, page 18 / 144 8 / 115 spinning, whereby continuous filaments are formed which have at least a portion of their surface comprising the second linking polymer, after which such formed filaments are cooled and removed and subsequently deposited onto a conveyor belt together with the first layer of filaments.

[017] Similarly, it is advantageous when in step c) the heated air acts on layers (T, M) for a period of 200 to 20,000 ms, preferably 200 to 15,000 ms, more preferably 200 to 10,000 ms and / or in step c) the heated air is fed through layers (T, M) and / or in step c) the heated air is fed through layers (T, M) at a speed of 0.2 to 4.0 m / s, preferably in the range 0.4 to 1.8 m / s.

[018] Advantageously, the method also includes the pre-consolidation step of the layers carried out after step b), before step c), where the pre-consolidation of the layers is carried out by heating the layers to a temperature in the range of 80 to 180°C, preferably 90°C to 150°C, more preferably 110°C to 140°C to partially soften the bonding polymers. DEFINITIONS

[019] The term “filament layer” refers to materials in filament form that are in the condition prior to the joining of the filaments for consolidation purposes, which is a procedure that can be carried out by various methods, for example creating bonds by air passage effect, calendering, etc. A “filament layer” consists of individual filaments between which a fixed mutual bond is not generally formed, despite these filaments Petition 870220076974, dated 08 / 26 / 2022, page 19 / 144 9 / 115 can, in a way, be pre-interconnected / pre-consolidated, with this pre-consolidation occurring during or shortly after filament deposition, which is performed, or was performed, as part of filament layer spreading. This pre-consolidation, however, still allows a substantial number of filaments to be freely mobile and thus repositionable. The aforementioned “filament layer” may consist of one or multiple layers gradually deposited from multiple spinning bundles.

[020] The term “filament” is defined here essentially as a continuous filament, while the term “staple fiber” refers to a fiber that is cut to a defined length. The terms “fiber” and “filament” are used here interchangeably. In the case of a cut fiber, the term “discontinuous fiber” is used exclusively.

[021] The terms “strand links” or “strand links” refer to the links that typically connect two strands at a location where those strands cross or at a location where they come into contact or, alternatively, where they join. Through strand links / strand links it is possible to connect more than two strands or to connect two parts of the same strand.

[022] Thus, the term “bond point” here represents the connection of two fibers / filaments at the point of contact by the interconnection of their components that have lower melting points. At the bond point, the component formed from the filament with the higher melting point is not shaped or damaged. Conversely, the term Petition 870220076974, dated 08 / 26 / 2022, page 20 / 144 10 / 115 “bonding impression” represents a surface on which the relief of a calender roll has acted. A bonding impression has a defined area given by the size of the relief on the bonding roll and, compared to the adjacent area, is usually thinner. During the bonding process, the bonding impression area is typically subjected to significant mechanical pressure, which, along with temperature, can affect the shape of all filament components within the bonding impression area.

[023] The term “single-component filament” or “single-component fiber” refers to a filament formed from a single polymer or a single mixture of polymers, which is differentiated from a two-component filament or a multi-component filament.

[024] The term “multicomponent fiber” or “multicomponent filament” designates a fiber or filament whose cross-section incorporates more than one individual partial component, while each of these independent components in the cross-section consists of a different polymeric compound or a different mixture of polymeric compounds. The term “multicomponent fiber” / “multicomponent filament” is therefore a superior term, which includes but is not limited to “bicomponent fiber” / “bicomponent filament”. The different components of multicomponent filaments are essentially arranged in clearly defined areas laid out along the cross-section of the filament and extend continuously along the length of the filament. A multicomponent filament may have a cross-section divided into several partial cross-sections consisting of various components of Petition 870220076974, dated 08 / 26 / 2022, page 21 / 144 11 / 115 random shapes or arrangements, including, for example, in a coaxial arrangement of partial cross-sectional components in a mutual random arrangement of partial cross-sectional components in the form of core and sheath, radial or so-called islands-in-the-sea, etc.

[025] The terms two-component and two-component used to describe filaments are used interchangeably here.

[026] The filament diameter measurement is expressed in μη units. The terms number of grams of filament per 9000 m (also denier or den) or number of grams of filament per 10000 m (dTex) are used to express the degree of fineness or coarseness of a filament with respect to the filament diameter (a circular cross-section of the filament is assumed) multiplied by the density of the material or materials used.

[027] Machine direction (MD) - in relation to the production of nonwoven fibrous material and the nonwoven fibrous material itself, the term machine direction (MD) represents the direction that essentially corresponds to the forward movement direction of the nonwoven fibrous material on the production line where this material is produced.

[028] Transverse direction (CD) - in relation to the production of nonwoven fibrous material and the actual nonwoven fibrous material itself, the term transverse direction (CD) represents the direction that is essentially transverse to the forward direction of movement of the nonwoven fibrous material on the production line where this material is produced, while located in the plane of the nonwoven fibrous material. Petition 870220076974, dated 08 / 26 / 2022, page 22 / 144 12 / 115

[029] “Nonwoven material” or “nonwoven fabric” is a fibrous sling or formation produced from directionally or randomly oriented filaments that are first formed during the creation of a filament layer and then consolidated together by friction or elicitation of cohesive or adhesive forces and finally formed by the creation of mutual bonds, while this consolidation is carried out thermally (e.g., by the effect of airflow, calendering, ultrasound effect, etc.), chemically (e.g., using an adhesive), mechanically (e.g., hydroentanglement, etc.), or alternatively by a combination of these methods. The term does not refer to fabrics formed by weaving or knitting or fabrics using yarns or fibers to form bonding points. The fibers may be of natural or synthetic origin and may be staple yarns, continuous fibers, or fibers produced directly at the processing site.Commercially available fibers have a diameter ranging from less than approximately 0.001 mm to more than approximately 0.2 mm and are supplied in various forms: short fibers (known as staple or chop fibers), continuous individual fibers (filament or monofilament fibers), untwisted bundles of filaments (combed fibers), and bundles of twisted filaments (yarns). A nonwoven fabric can be produced using many methods, including technologies such as meltblown, spunbond, spunmelt, solvent spinning, electrostatic spinning, carding, film fibrillation, fibrillation, airflow spinning, dry spinning, wet spinning with staple fibers, and various combinations thereof. Petition 870220076974, dated 08 / 26 / 2022, page 23 / 144 13 / 115 processes as known in the state of the art. The base weight of nonwoven fabrics is generally expressed in grams per square meter (g / m2).

[030] In the sense used in this document, the term layer refers to the partial component or element of a fabric. A layer may be in the form of multiple filaments produced in a single spinning beam or in two or more consecutively arranged spinning beams that create essentially the same filaments. For example, two consecutively arranged spinning beams intended to perform the spunbond (continuous spinning) method, having essentially the same configurations and processing polymers of essentially the same composition, may combine to produce a single layer. On the other hand, two spunbond-type spinning beams (obtained by continuous spinning), one of which produces, for example, single-component filaments and the other produces, for example, two-component filaments, will form two different layers.The composition of a layer can be determined based on knowledge of the configurations and individual components that determine the composition of the resin (polymer) used to create the layer, or through analysis of the nonwoven fabric itself, for example, using electron microscopy, or alternatively by analyzing the composition used in the production of the filaments contained in the layer using DSC or NMR methods. Adjacent layers of filaments do not necessarily have to be strictly separated; layers in the boundary region can mix as a result of the filaments of a deposited layer. Petition 870220076974, dated 08 / 26 / 2022, page 24 / 144 14 / 115 subsequently falling into the gaps between the filaments of a previously deposited layer.

[031] The spunbond (continuous spinning) process is a nonwoven fabric production process that involves the direct conversion of polymers into filaments, which is followed directly by the deposition of these created filaments, thus creating a layer of nonwoven filaments containing randomly arranged filaments. This nonwoven layer of filaments is subsequently consolidated to enclose the nonwoven fabric by creating bonds between the filaments. The consolidation process can be carried out using various methods, for example, by the air passage effect, calendering, etc.

[032] Activation is understood as the process by which fibers, filaments or fibrous structures that are in semi-stable states (for example, in the lowest possible energy state without crystallization occurring) are heated and then slowly cooled so that the described semi-stable state changes to a different, more stable state (for example, a state corresponding to a different crystallization phase). If the new state assumes a different volume from the original state, i.e., if it assumes a smaller volume, we define this as contraction or shrinkage.

[033] The term cross-section enabling crimping refers to multicomponent filaments made up of components with different characteristics arranged along the cross-section in such a way that during their production or when subsequently heated to or above the temperature of Petition 870220076974, dated 08 / 26 / 2022, page 25 / 144 15 / 115 activation and subsequently cooled slowly to achieve filament curling, during which these filaments follow the force vectors that cause shrinkage. The release of the filament creates the so-called helical curl, although the filaments contained within the fibrous layer are prevented from creating ideal helices due to mutual adhesion between these filaments. In multicomponent filaments it is possible to determine the center of gravity for each individual component in the cross-section of the filament (based on weighing the surfaces / positions of these components in a given cross-section - see Figure 5). Regardless of the theoretical fundamentals, we assume that if the center of gravity of all surfaces of each of the components is located essentially at the same point, then it is not possible to obtain filament curling by heating it to the activation temperature.For example, in two-component filaments with a circular cross-section, where one of the polymeric components forms the core and the other the sheath, and both are relatively concentric with each other, the center of gravity of both components is at the center of the cross-section.

[034] The term compressibility here refers to the distance in millimeters by which a nonwoven fabric is compressed by the effect of a defined load during the elasticity measurement.

[035] The term recovery here refers to the ability of the tissue to regain its original shape after being compressed. This relates primarily to the ability to regenerate (recover) volume based on the ratio between Petition 870220076974, dated 08 / 26 / 2022, page 26 / 144 16 / 115 the thickness of the fabric after the release of the acting load and the initial thickness of that fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[036] Preferred embodiments of the invention will be described in more detail below with reference to the accompanying schematic drawings, which show:

[037] Figure 1 shows examples of external shapes of cross-sections of filaments.

[038] Figure 2 shows examples of cross-sections that do not support filament curling.

[039] Figure 3 shows a graph showing the orientation of the directional arrangement of filaments in the layer plane according to the invention.

[040] Figure 4 shows a photograph of filament sections before and after activation.

[041] Figure 5 shows examples of cross-sections that support filament crimping.

[042] Figure 6 shows a comparison of filament micrographs with various levels of crimping.

[043] Figures 7A and 7B show a comparison of cross-sections of consolidated tissues using a relief and a consolidated tissue using tie points.

[044] Figure 8 shows an example of a cross-section of the second layer M.

[045] Figure 9 shows an example of a cross-section of another second layer M.

[046] Figure 10 shows an example of a cross-section of another second layer M. Petition 870220076974, dated 08 / 26 / 2022, page 27 / 144 17 / 115

[047] Figure 11 shows a top-down view of the second layer M.

[048] Figure 12 shows a schematic description of the production line.

[049] Figure 13 shows a perspective view of a device for the Martindale Medium Abrasion Resistance Grade Test.

[050] Figure 14 shows a classification scale for evaluating the Martindale Medium Abrasion Resistance Grade Test. EXAMPLES OF IMPLEMENTATION OF THE INVENTION

[051] The object of the invention is a thermally consolidated nonwoven fabric made of continuous spunmelt filaments containing at least one first layer of filaments (T) and a second layer of filaments (M).

[052] The first layer of filaments (T) mainly contains continuous two-component or multi-component filaments containing a higher-rigidity polymer, while at least one of the filament components is predominantly composed of the first carrier polymer A1 with a higher rigidity and at least one of the other components that is present at least in a part of the filament surface, predominantly comprising the first linker polymer B1 with a lower melting temperature than the first carrier polymer A1. Without wanting to be limited by theory, it is believed that the filaments containing a higher-rigidity polymer impart volume and recovery to the nonwoven fabric according to the invention. For the solution according to the invention, it may Petition 870220076974, dated 08 / 26 / 2022, page 28 / 144 18 / 115 can be advantageous when the first layer of T-filaments contains continuous spunbond filaments (heat-bonded continuous filaments).

[053] The second filament layer (M) mainly contains continuous bi- or multicomponent filaments containing a polymer with lower stiffness, while at least one of its components is mainly composed of the second carrier polymer A2 with lower stiffness than the first carrier polymer A1 and at least one of the other components that is present on a part of the filament surface consists mainly of the second linking polymer B2 which has a lower melting temperature than the second carrier polymer A2 and which is compatible with the first linking polymer B1 of the first filament layer T. Without wanting to be limited by theory, it is believed that the filaments containing a lower stiffness polymer provide the nonwoven fabric, according to the invention, with greater softness, extensibility and improved touch and feel properties of the fabric.For the solution according to the invention, it may be advantageous when the second layer of M filaments contains continuous spunbond filaments (heat-bonded continuous filaments).

[054] Alternatively, the second layer of filaments (M) may consist, for example, of lower stiffness natural fibers combined with the bonding element consisting of polymer B2 (bonding filaments, powder, etc.). In this case, the force required to bend a single natural fiber is compared with the force required to bend a single fiber of the same fineness (denier) and circular cross-section created from polymer A1. For the Petition 870220076974, dated 08 / 26 / 2022, page 29 / 144 19 / 115 solution according to the invention, it is advantageous that this ratio be greater than 1:1.1, better still greater than 1:1.2, advantageously greater than 1:1.5.

[055] The compatibility of polymers B1 and B2 is defined as having the same similar melting point and the ability to combine very well and create strong and stable mixtures (blendings). One skilled in the art will understand that polymers have specific behaviors. When heated, the softening temperature is initially exceeded, where the polymer begins to soften and, under hot air consolidation conditions, is able to join filaments, and subsequently the melting temperature is reached, where the polymer transitions entirely to the liquid phase, which in terms of thermal consolidation is undesirable, since an entirely liquid polymer can move freely through the structure, drip, create undesirable agglomerates, etc. In terms of the invention, it is desirable that polymers B1 and B2 exhibit a common range in their intervals (softening temperature, melting temperature).Generally, it can be assumed that well-mixable polymers with a melting temperature difference not exceeding 10°C, advantageously not exceeding 5°C, should be suitable for use according to the invention. It is advantageous to use as polymer B1 the same polymer as polymer B2.

[056] B1 and B2 linking polymers can be part of a blend with another polymer and / or various additives (e.g., color pigments, additives that support the mutual compatibility of polymers, functional additives, additives that alter the surface properties of polymers, etc.) can be blended with them. The blend of Petition 870220076974, dated 08 / 26 / 2022, p. 30 / 144 20 / 115 B1 and B2 polymers may consist of new clean polymers; may consist of a mixture of clean polymers and recycled polymeric material; or may consist of purely recycled material.

[057] The first carrier polymer A1 with a higher stiffness (than A2) is a thermoplastic polymer suitable for processing in a spunmelt production line belonging, advantageously, to the groups of polyolefins, polyesters, polyamides or copolymers of these groups. An advantageous solution represents, for example, polypropylene (PP), polyethylene terephthalate (PET), polylactic acid (PLA) and others.

[058] The second carrier polymer A2 with a lower stiffness (than A1) is a thermoplastic polymer suitable for processing in a spunmelt production line belonging, advantageously, to the groups of polyolefins, polyesters, polyamides or copolymers of these groups. An advantageous solution represents, for example, polypropylene (PP), polyethylene terephthalate (PET), polylactic acid (PLA) and others.

[059] Carrier polymers A1 and A2 may consist of new clean polymers; may consist of a mixture of clean polymers and recycled polymeric material; or may consist of purely recycled material.

[060] The stiffness of polymers can be expressed, for example, using the flexural modulus of elasticity (flexural modulus) or the tensile modulus of elasticity (Young's modulus), which are mutually correlated in a significant way. Both moduli can be specified for a specific polymer or for a mixture of Petition 870220076974, dated 08 / 26 / 2022, page 31 / 144 21 / 115 polymers and thus it is possible to express the stiffness of the polymers and the stiffness of an element of the filament or the stiffness of the polymer combination representing the entire filament.

[061] For example, the average flexural moduli for the selected polymers are presented in the following table: Polymer Flexural Modulus (Modulus of Flexure) Tensile Modulus (Young's Modulus) Polyethylene (LDPE) 100 - 780 MPa 135 - 860 MPa Polypropylene (PP) 900 - 1700 MPa 1200 - 2000 MPa Polylactic Acid (PLA) 215 - 1830 MPa 350 - 2800 MPa Polyethylene terephthalate (PET) 1900 - 3310 MPa 2000 - 3800 MPa

[062] For the solution according to the invention, it is advantageous when the difference between the stiffness of the first carrier polymer A1 and the stiffness of the second carrier polymer A2, expressed by the tensile modulus of elasticity (Young's modulus), is at least 100 MPa, better still at least 200 MPa, better still at least 300 MPa, better still at least 400 MPa, advantageously at least 500 MPa.

[063] For the solution according to the invention, it is advantageous when the difference between the stiffness of the first carrier polymer A1 and the stiffness of the second carrier polymer A2, expressed by the flexural modulus of elasticity (flexural modulus), is at least 100 MPa, better Petition 870220076974, dated 08 / 26 / 2022, page 32 / 144 22 / 115 still at least 200 MPa, better still at least 300 MPa, even better still at least 400 MPa, advantageously at least 500 MPa.

[064] The tensile modulus of elasticity and the flexural modulus of elasticity must be specified for each specific polymer individually. The flexural modulus of elasticity is in accordance with ISO 178:2010 and the tensile modulus of elasticity is in accordance with CSN EN ISO 527-1 (640604).

[065] B1 and B2 linkage polymers with a lower melting temperature (than A1 and A2) are suitable thermoplastic polymers for processing in a spunmelt production line, advantageously belonging to the polyolefin, polyester, polyamide or copolymer groups of these groups. A suitable solution is provided, for example, by polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polylactic acid (PLA), nylon and especially the so-called low melting point copolymers of the groups specified above (e.g. PP / PE copolymer, PET copolymer, PLA copolymer, etc.).

[066] For example, a two-component filament contains 2 elements arranged within the cross-section of the filament. For example, a core / sheath (C / S) type of two-component filament contains two elements, where one represents the core of the filament and the other surrounds it and forms the surface of the filament. The carrier polymer A with defined stiffness is advantageously used here for the core, where it can form the core directly, or represent one of the input raw materials of a mixture that forms the core. Petition 870220076974, dated 08 / 26 / 2022, p. 33 / 144 23 / 115 of the filament. The union of polymer B with the lower melting point forms the sheath, that is, one of the raw materials used in a mixture that forms the filament sheath. Similarly, it is possible to describe two-component filaments of the side / side (S / S), eccentric core / sheath (eC / S) type, etc.

[067] For the solution according to the invention, it is advantageous when the first component of a two-component filament (e.g., core, side) has a higher stiffness in the first layer T than in the second layer M. For the solution according to the invention, it is advantageous when the difference between the stiffness of the first component of the two-component filament in the first layer T and the stiffness of the first component of the two-component filament in the second layer M, as expressed by the tensile modulus of elasticity (Young's modulus), is at least 100 MPa, better still at least 200 MPa, better still at least 300 MPa, better still at least 400 MPa, advantageously at least 500 MPa.

[068] For the solution according to the invention it is advantageous when the difference between the stiffness of the first two-component filament in the first layer T and the stiffness of the first two-component filament in the second layer M, as expressed by the modulus of elasticity in bending (flexural modulus) is at least 100 MPa, better still at least 200 MPa, better still at least 300 MPa, better still at least 400 MPa, advantageously at least 500 MPa.

[069] Without intending to be limited to an exhaustive list, several examples of material compositions according to the invention are presented. Petition 870220076974, dated 08 / 26 / 2022, p. 34 / 144 24 / 115

[070] The solution according to the invention may, for example, contain a first layer T consisting of continuous core / sheath (C / S) filaments where the core is made of PET (=A1) and the sheath of PE (=B1) and a second layer M consisting of continuous core / sheath (C / S) filaments, the core being made of PP (=A2) and the sheath of PE (=B2). The stiffness of polymers A1 and A2, expressed by the modulus of elasticity in bending, differs by more than 500 MPa, polymers B1 and B2 are the same (PE) and their melting point is lower than the melting point of polymers A1 and A2.

[071] The solution according to the invention may, for example, contain a first layer T consisting of continuous core / sheath (C / S) type filaments where the core is made of PLA (=A1) and the sheath of PE (=B1) and a second layer M consisting of continuous eccentric core / sheath type filaments (eC / S), the core being made of PP (=A2) and the sheath of PE (=B2). The stiffness of polymers A1 and A2, expressed by the modulus of elasticity in bending, differs by more than 200 MPa, polymers B1 and B2 are the same (PE) and their melting point is lower than the melting point of polymers A1 and A2. The filaments in layer M will likely exhibit a tendency to curl or spontaneous curl (latent curl or self-curl).

[072] The solution according to the invention may, for example, contain a first layer T consisting of continuous core / sheath (C / S) type filaments where the core is made of PET (=A1) and the sheath of CoPLA (=B1) and a second layer M composed of continuous filaments of the type Petition 870220076974, dated 08 / 26 / 2022, p. 35 / 144 25 / 115 side / side (S / S), one side being composed of PLA (=A2) and the other of CoPLA (=B2). The stiffness of polymers A1 and A2, expressed by the flexural modulus of elasticity, differs by more than 100 MPa. Polymers B1 and B2 are the same (coPLA), and their melting point is lower than the melting point of polymers A1 and A2. The filaments in the M layer will likely show a tendency towards curling or spontaneous curling (latent curl or self-curling).

[073] The solution according to the invention may, for example, contain a first layer T consisting of continuous core / eccentric sheath (eC / S) type filaments where the core is made of PET (=A1) and the sheath of PP1 (=B1) and a second layer M consisting of continuous core / sheath (C / S) type filaments where the core is made of PP2 (=A2) and the sheath by PP3 (=B2). The stiffness of polymers A1 and A2, expressed by the flexural modulus of elasticity, differs by more than 200 MPa. Polymers B1 and B2 are compatible (PP1 and PP3), and their melting point is lower than the melting point of polymers A1 and A2. The filaments in the T-layer will likely exhibit a tendency towards curling or spontaneous curling (latent curling or self-curling).

[074] The solution according to the invention may, for example, contain a first layer T consisting of continuous core / eccentric sheath (eC / S) type filaments, where the core is made of PET (=A1) and the sheath of coPET (=B1), and a second layer M consisting of continuous core / eccentric sheath (C / S) type filaments, where the core is made of PLA (=A2) and the sheath of coPET (=B2). The stiffness of polymers A1 and A2 is expressed by the modulus Petition 870220076974, dated 08 / 26 / 2022, p. 36 / 144 26 / 115 flexural elasticity differs by more than 100 MPa, polymers B1 and B2 are the same (coPET) and their melting point is lower than the melting point of polymers A1 and A2. The filaments in both T and M layers will likely exhibit a tendency to curl or spontaneous curl (latent curl or self-curl).

[075] The solution according to the invention may, for example, contain a first layer T composed of continuous side / side (S / S) filaments where one side is made of PET (=A1) and the other side of coPET (=B1) and a second layer M consisting of continuous side / side (S / S) filaments, one side consisting of PLA (=A2) and the other of coPET (=B2). The stiffness of polymers A1 and A2, expressed by the flexural modulus of elasticity, differs by more than 100 MPa, polymers B1 and B2 are the same (coPET), and their melting point is lower than the melting point of polymers A1 and A2. The filaments in both layers T and M will likely exhibit a tendency to curl or spontaneous curl (latent curl or self-curl).

[076] The solution according to the invention may, for example, contain a first layer T composed of continuous core / eccentric sheath (eC / S) type filaments, where the core is made of PET (=A1) and the sheath of PE (=B1) and a second layer M consisting of short cellulose fibers crimped for air application in a mixture with PE powder. The force ratio required to bend a single filament is greater than 1.5.

[077] The solution according to the invention may contain, for example, a first layer (T), composed of continuous core / sheath type filaments (eC / S), in which the Petition 870220076974, dated 08 / 26 / 2022, p. 37 / 144 27 / 115 The core is made of PP1 (=A1) and the sheath of PE (=B1), and a second layer (M), consisting of continuous core / sheath type filaments (eC / S), where the core is made of PP2 (=A2) and the sheath of PE (B2). The stiffness of polymers A1 and A2, expressed by the modulus of elasticity in bending, differs by more than 100 MPa, with polymers B1 and B2 being identical (PE) and their melting point lower than the melting point of polymers A1 and A2. The filaments in both layers (T, M) will most likely exhibit a tendency to curl or spontaneous curl (latent curl or self-curl).

[078] The solution according to the invention may contain, for example, a first layer (T), composed of continuous core / sheath type filaments (eC / S), wherein the core is made of PP (=A1) and the sheath of PE (=B1), and a second layer (M), composed of continuous core / sheath filaments (eC / S), wherein the core is made of a mixture (=A2) of multiple polypropylene-based polymers with different properties (not to be limited by an exhaustive list, the polymer mixture may be made of, for example, a homopolymer and a copolymer of polypropylene, polypropylene with a higher and lower melt flow rate, etc.), and the sheath is made of PE (B2). The stiffness of polymers A1 and A2, expressed by the flexural modulus of elasticity, differs by more than 100 MPa, with polymers B1 and B2 being identical (PE) and having a lower melting point than polymers (A1 and A2).The filaments in both layers (T and M) will most likely exhibit a tendency towards curling or spontaneous curling (latent curling or self-curling). Petition 870220076974, dated 08 / 26 / 2022, page 38 / 144 28 / 115

[079] The stiffness of the filaments can be affected not only by the polymer used, but also, for example, by the thickness of the filaments. The terms “filament thickness” and “filament diameter” are used interchangeably in this application.

[080] According to the invention, it may be advantageous for the thickness of the d1 filaments of the first layer (T) to be greater than the thickness of the d2 filaments of the second layer (M). For example, in an application where the most important factor is the volume of the nonwoven fabric combined with the associated requirement of a smooth surface on the nonwoven fabric.

[081] In terms of the invention, it may be advantageous when the thickness of the filaments d1 in the first layer (T) and d2 in the second layer (M) is the same or very similar, i.e., where d1 / d2 is 0.8 to 1.3. For example, in applications where the homogeneity of the material on the surface and in the cross-section is important.

[082] According to the invention, it may be advantageous for the thickness of the d1 filaments of the first layer to be less than the thickness of the d2 filaments of the second layer. For example, in applications where the overall softness and flexibility of the material are important. One skilled in the art will readily understand which combination of filament thicknesses according to the invention is advantageous for their application.

[083] The stiffness of the filaments can also be affected by the percentage share of polymeric components in the filament. For example, in the case of two filaments of the same diameter d in the core / sheath arrangement, where the core is Petition 870220076974, dated 08 / 26 / 2022, p. 39 / 144 29 / 115 consisting of polymer A and a sheath of polymer B, the filament with the lowest percentage share of the core component, i.e., polymer A (e.g., 50%), will have a lower overall stiffness than the filament with a higher share of the core component, i.e., polymer A (e.g., 30%). Each of the filaments of the first layer (T) and the second layer (M) may be contained in the nonwoven fabric one or more times.

[084] For example, the first layer T can form the base layer and the second layer M can form the surface of the product (e.g., TM, TTM, MTM, MTTM, TMM, TTMM etc.).

[085] For example, the first layer T, with its open structure, can form an entrance area, which is narrowed in the second layer M (e.g., TM, TTM, TMT, TMM, TTTM, etc.).

[086] For example, the T and M layers can alternate, where, for example, the soft thickness of the intermediate M layers is made thinner by the material and masked by the stiffness of the T layers (e.g., MTM, MTMT, MTMTM, TMTMT etc.).

[087] A nonwoven fabric according to the invention may, in addition to the first layer T and the second layer M, also contain another layer X, provided that this layer is thermally bondable with the first and second layers. For example, possible compositions include types TXM, MXT, XMT, XTM, MTXTM, XMTMX, MTXM and many others.

[088] According to the invention, the nonwoven fabric may also include several pairs of TM layers. For example, in a nonwoven fabric produced in 3 yarn beams S1 - S2 - S3, the following may be created: S1 layer T1, S2 Petition 870220076974, dated 08 / 26 / 2022, p. 40 / 144 30 / 115 layer M1 (versus layer T1), which is simultaneously layer T2 (versus layer M2) and layer S3 M2.

[089] According to the invention, the nonwoven fabric is thermally consolidated. Energetically advantageous is the thermal consolidation of essentially the entire volume of the fibrous layers that form the nonwoven fabric, where the bonding point can be created at any intersection of the filaments in the structure. During this type of thermal consolidation, according to the invention, due to the passage of heat through the filament layer, the polymer B in both layers softens and even melts, both on the surface and at the interface between the layers. At the contact points of the filaments, the molten polymer bonds and during subsequent cooling hardens and connects the filaments in contact. The structure of the filaments created in this way generally exhibits a soft-loft type of softness, flexibility and often also recovery.A suitable bonding method according to the invention is, for example, bonding using a stream of hot air, or particularly for lower base weights, bonding using infrared radiation.

[090] For example, a two-component filament contains 2 elements arranged within the cross-section of the filament. For example, a core / sheath (C / S) type of two-component filament contains two elements, where the first represents the core of the filament and the second surrounds it and forms the surface of the filament. The polymer with the lower melting temperature B is advantageously used here for the sheath, where it can form the sheath directly, or represents one of the input raw materials of a mixture. Petition 870220076974, dated 08 / 26 / 2022, page 41 / 144 31 / 115 that forms the filament sheath. Polymer A with defined stiffness forms the core or represents one of the input raw materials of a mixture that forms the core sheath. Similarly, it is possible to describe two-component filaments of the side / side (S / S) type, the eccentric core / sheath type (eC / S), etc. The arrangement of the filament components can be known based on the configurations used in its production or can be identified by the "estimation of the filament cross-section type" method.

[091] For the solution according to the invention, it is advantageous that the second component of the two-component filament (e.g., side sheath) has a lower melting temperature. For the solution according to the invention, it is advantageous that the difference between the melting temperature of the first and second components of the two-component filament is at least 5°C, better still at least 10°C, advantageously at least 15°C.

[092] The melting temperature of polymer B with the lower melting temperature is preferably evaluated in relation to the respective polymer A with a defined stiffness. For example, in the first layer, the melting temperature of polymer B1 is evaluated in relation to the melting temperature of polymer A1. Due to the fact that the first layer T and the second layer M are interconnected by means of polymers B1 and B2, it is necessary to also take into account polymer A2 and thus evaluate the melting temperature of both polymers B1 and B2 in relation to it. The difference in the melting temperature of polymers A2 and B1, respectively B2, is at least 5°C, better yet at least 10°C, advantageously at least 15°C. Petition 870220076974, dated 08 / 26 / 2022, page 42 / 144 32 / 115

[093] Thermal consolidation fundamentally affects the resulting properties of nonwoven fabric, which is given by the intensity of filament interlinking, which depends on several values, such as particularly the amount of bonding polymer in the structure, the amount of heat supplied during the course of bonding and the bonding temperature, density of filaments in the structure, etc.

[094] For example, a filament layer composed of two-component core / sheath filaments in an 80:20 ratio contains a relatively small amount of bonding polymer, and the individual bonding points between the filaments will be composed of a small amount of material, which can be separated with relatively low force. The resulting structure will likely be relatively softer (as expressed, for example, by the flexibility and compressibility of nonwoven fabric) due to the bending effect of the filaments and the looseness of the bonds, and will also be less resistant to friction. On the other hand, for example, a filament layer composed of two-component core / sheath filaments in a 50:50 ratio contains a relatively large amount of bonding polymer, and the individual bonding points between the filaments are composed of a large amount of material.A structure created in this way will be relatively more rigid, exhibit a higher degree of recovery, and be more resistant to friction. For example, a filament layer composed of two-component core / sheath filaments in a 20:80 ratio contains a relatively large amount of bonding polymer. Petition 870220076974, dated 08 / 26 / 2022, page 43 / 144 33 / 115 and the individual connection points between the filaments will consist of a very large amount of material interconnected only by exceptionally thin filaments made up of the original filament cores. A structure formed in this way should be relatively soft, but will probably be deficient in volume.

[095] For example, a layer of filaments bonded at a lower temperature corresponding to the softening of the bonding polymer or a very short exposure to a higher temperature should contain relatively very weak bonds between the filaments, which will be easy to break. A softer structure with very low abrasion resistance can be expected. On the other hand, for example, a layer of filaments bonded at a higher temperature that exceeds the temperature of the bonding polymer and / or by a long exposure time to a suitable temperature should contain relatively strong bonds between the filaments created by the melting and redefinition of the entire bonding polymer. A more rigid structure with good recovery and good abrasion resistance can be expected.

[096] For example, a layer of very thin filaments will contain a large number of bonding points per unit volume, while, on the other hand, a layer of thicker filaments will contain, with the same basic weight, a significantly smaller number of bonding points, however, these filaments generally exhibit greater stiffness.

[097] By using appropriate settings for the parameters mentioned above, it is possible to produce Petition 870220076974, dated 08 / 26 / 2022, pp. 44 / 144 34 / 115 intentionally a non-woven fabric exhibiting greater softness, flexibility, stiffness, abrasion resistance, etc.

[098] With materials according to the invention, where two layers of filaments with different parameters are combined, it is possible to establish conditions such that, for example, one layer is less interconnected and the other layer is more interconnected. For example, with a lower degree of interconnection in the first layer T, the layer stiffness should decrease relative to the reduction in abrasion resistance, while maintaining the layer's recovery. If the same bonding conditions provide a higher degree of bonding of the material containing the second layer M with a lower stiffness that achieves relatively good abrasion resistance, while maintaining a degree of softness given by the polymer composition and supported, for example, by the fineness of the filaments, the result can be a material according to the invention that combines high softness, abrasion resistance on the application side (second filament layer M), and recovery.

[099] Without wanting to be limited by theory, it is believed that the combination of thermal consolidation throughout the volume of the nonwoven fabric (e.g., hot air bonding) in combination with filaments containing A1 polymer with higher stiffness is the main reason for layer recovery. The filaments are interconnected at small bonding points found throughout the volume of the nonwoven fabric, and between the individual bonding points there are—depending on the layer volume—relatively small sections of filaments pointing in all directions in 3D space. The overall structure is created at a higher temperature (bonding temperature) than the solid state of the polymer. Petition 870220076974, dated 08 / 26 / 2022, pp. 45 / 144 35 / 115 A is maintained, but allows a change in its crystallization state, which is maintained at a relatively low cooling rate. Namely, in the case of compression in the z direction (thickness of the nonwoven fabric), this resulting structure has a strong tendency to return to its initial state (recovery). Generally, it can be assumed that the greater the stiffness of polymer A, the greater the tendency of the nonwoven fabric to return to its original state (recovery).Polymer B, with a lower melting temperature, will contribute significantly less to recovery because, unlike polymer A, during the thermal consolidation process it will be partially or totally melted (to allow for filament interconnection), and may change position and shape (for example, during thermal consolidation, it may concentrate relatively in filament contact points = bonding points and, conversely, its contribution may decrease in the filaments between the bonding points), etc.

[0100] The second layer (M) containing the lower stiffness A2 polymer is, given its presence in the composite, bonded under the same conditions as the first layer (T). Here too, the aforementioned structure of bonding points and relatively short filament sections between them is created. Given the lower stiffness of the A2 polymer, the tendency towards softness and malleability of the layer is supported. Specifically, human perception of layer stiffness may differ from standard methods of evaluating layer stiffness (softness (Handle-O-Meter), compressibility, flexibility), and the layer with filaments containing A2 polymer with lower stiffness is generally subjectively evaluated as better. Petition 870220076974, dated 08 / 26 / 2022, page 46 / 144 36 / 115 in terms of softness compared to a layer containing A1 polymer filaments with greater stiffness, even though in specific cases, for example, the softness measurement value (Handle-O-Meter) is the same or even higher.

[0101] Surprisingly, it was discovered that the nonwoven fabric produced according to the invention exhibits unique properties. The combination of filaments containing a stiffer polymer and filaments containing a less stiff polymer creates a composite that generally exhibits: - a degree of extensibility generally comparable to a material produced only from second-layer M filaments (superior to that of the material produced from first-layer T filaments); - a degree of recovery generally comparable to, or exhibiting only a relatively small reduction compared to, material produced from first-layer T filaments; - a degree of softness expressed by measuring the compressibility of the nonwoven fabric, generally comparable to, or exhibiting only a relatively small reduction in, the material produced from second-layer M filaments.

[0102] It may be advantageous for the nonwoven fabric according to the invention that the first layer (T) be made up of thicker filaments (with a thickness greater than 25 microns, better still greater than 30 microns, advantageously above 35 microns, but preferably not more than 100 microns, better still not more than 70 Petition 870220076974, dated 08 / 26 / 2022, p. 47 / 144 37 / 115 microns, advantageously no more than 50 microns) containing a higher percentage share of polymer A1 (e.g., at least 55% by weight of polymer A1, better still at least 60% by weight of polymer A1, better still at least 65% by weight of polymer A1, advantageously at least 70% by weight of polymer A1 of the total filament weight) and a lower percentage share of polymer B1 (e.g., no more than 45% by weight, better still no more than 40% by weight, better still no more than 35% by weight, advantageously no more than 30% by weight of polymer B1 of the total filament weight).At the same time, the second layer (M) consists of thinner filaments (with a thickness of less than 30 microns, better still below 25 microns, advantageously below 20 microns) containing a lower percentage share of polymer A2 (e.g., no more than 60% by weight, better still no more than 55% by weight, better still no more than 50% by weight, advantageously no more than 45% by weight of polymer A2 of the total filament weight) and a higher percentage share of polymer B2 (e.g., more than 40% by weight, better still more than 45% by weight, advantageously more than 50% by weight of polymer B1 of the total filament weight).Surprisingly, it was discovered that a nonwoven fabric produced in this way exhibits a high volume and recovery of the first layer (T), while the high percentage of free space in the structure (void volume) together with the lower filament bonding strength (resulting from the smaller number of bonding points at the filament contact sites and at the same time the smaller volume of the B1 bonding component) will support the “soft-loft” type of softness, but at the cost of a “rougher” perception of touch and subjective feel. Petition 870220076974, dated 08 / 26 / 2022, page 48 / 144 38 / 115 Concomitantly, the second layer (M) with fine filaments and a higher percentage of B2 binding component will exhibit less volume; however, when soft polymers are used, it will exhibit excellent touch and feel properties, which can be further supported by, for example, additives to improve touch and feel (e.g., erucamide for a silky touch and feel, specific additives for the so-called cotton touch, etc.). A combination carried out in this way provides a voluminous material with a high subjective perception of softness. When touched by the side of the second layer (M), on initial contact, the skin receives a pleasant sensation of touch to the fabric, which simultaneously flexes smoothly even under light pressure. At the same time, a certain roughness of the first layer (T) is masked by the softness and silkiness of the second layer (M).As pressure increases, the second, bulkier layer (T) also begins to gradually compress, exhibiting greater resistance to pressure (expressed, for example, by elasticity measurements). The increase in required pressure is gradual, and so too does the resistance to compression gradually increase; thus, the material is subjectively perceived as pleasantly soft and comfortable.

[0103] For nonwoven fabric according to the invention, it may be advantageous for the basis weight of the first layer (T) to be greater than the basis weight of the second layer (M). For example, the basic weight ratio of layer T to the basic weight of layer M is advantageously at least 55:45, even better at least 60:40, even better at least 65:35, advantageously at least 70:30, but less than 95:5, even better than 95:10, advantageously less than 85:15. Petition 870220076974, dated 08 / 26 / 2022, pp. 49 / 144 39 / 115

[0104] For the nonwoven fabric according to the invention, it may be advantageous that the ratio between the basis weight of the first layer T produced from a spinneret and the basis weight of the second layer M produced in a spinneret corresponds approximately to the average density of the polymeric composition of the filaments in these layers. This solution is advantageous mainly from the point of view of production costs, where it is possible to utilize the total operational performance of both spinnerets when producing in standard spunbond (continuous spinning) type spinnerets.If, based on the ratio of the weighted average densities of the polymer and the total required base weight of the layered nonwoven fabric, a calculation is performed to determine the recommended base weight of the individual layers T, M, it is advantageous when, for example, the basis weight of the first layer T and the second layer M does not differ by more than 5 g / m2 from the calculated value, better still does not differ by more than 4 g / m2 from the calculated value, better still does not differ by more than 3 g / m2 from the calculated value, advantageously does not differ by more than 2 g / m2 from the calculated value.

[0105] Several examples are provided in the table (density in kg / m3, base weight in g / m2). oao First layer T A1 density A1 Percentage share of A1 B1 Density B1 Percentage share of B1 Weighted average density of PET polymer 1380 80% PE 918 20% 1288 Petition 870220076974, dated 08 / 26 / 2022, page 50 / 144 40 / 115 PET 1380 50% PE 918 50% 1149 PLA 1250 60% PE 918 40% 1117 PET 1380 70% PP 943 30% 1249 ο ?π3 a O Second layer M CM density A2 Percentage share A2 B2 density B2 Percentage share B2 Weighted average polymer density PP 943 40% PE 918 60% 928 PP 943 60% PE 918 40% 933 PP 943 50% PE 918 50% 931 coPET 1360 40% PP* 935 60% 1105 NT option with TM layers, total gsm 100 T / M of weighted density averages advantageous gsm of T (calculated value) advantageous gsm of T (calculated value) advantageous gsm of TM (recommended range for 4-2 gsm) advantageous gsm of M (recommended range for 4-2 gsm) 1 1.239 58 42 56-60 40-44 2 1.23 55 45 53-57 43-47 3 1.20 55 45 53-57 43-47 Petition 870220076974, dated 08 / 26 / 2022, page 51 / 144 41 / 115 1,13 53 47 51-55 45-49

[0106] A similar calculation is also performed for the case where the nonwoven fabric contains more than two layers.

[0107] In one of the advantageous solutions according to the invention, the weighted average density of the polymer in the filaments of the first layer T and the second layer M differs. This density indicates the weight of the polymer per unit volume. If the difference in values ​​is too large, undesirable effects may occur, where the filaments of the composition with a significantly higher weighted average act on the filaments of the layer with a lower weighted average, compressing them unevenly and creating undesirable effects, especially when the higher weighted average polymer in the filaments is exhibited by filaments in layer M.For one of the solutions according to the invention, the ratio of the weighted average density of the polymers in the continuous filaments of the first layer (T) to the weighted average density of the polymers in the continuous filaments of the second layer (M) is 1.0 to 1.5, preferably 1.1 to 1.3 and / or the ratio of the basic weight of the first layer (T) to the basic weight of the second layer (M) is 1.0 to 1.5, preferably 1.1 to 1.3.

[0108] The polymer groups (polyolefins, polyesters) listed above differ not only in their stiffness, but also in other different properties, which can be used to support the desired final characteristics of the nonwoven fabric. Polyesters (for example, Petition 870220076974, dated 08 / 26 / 2022, page 52 / 144 42 / 115 PET, PLA, or their copolymers exhibit shrinkage. For proper crystallization, these polymers generally require more time than is available while the filaments cool during the spunmelt production process. Reheating filaments containing these polymers (e.g., a narrow stream of hot air, "hot air blade," hot air bonding, infrared radiation) usually results in recrystallization, where the new, more stable crystallization state generally occupies a smaller volume than the semi-stable crystallization state = shrinkage.

[0109] Shrinkage is generally considered an undesirable event, however, if properly controlled, it can bring advantages. For example, our former patent application PV 2018-647 (not yet published) describes the use of controlled shrinkage of polymers for the purpose of producing a bulky material with recovery and so-called structural softness.

[0110] For the material according to the invention, it may be advantageous that the first layer T, or alternatively both layers M and T, contain continuous filaments with a cross-section that does not support curling. These may be multicomponent, preferably two-component. Regardless of the theoretical basis, we are convinced that the center of gravity of the cross-sectional surfaces composed of one component arranged along the cross-section of the filaments is located essentially in the same position as the center of gravity of the cross-section of all other components, whose cross-section Petition 870220076974, dated 08 / 26 / 2022, page 53 / 144 43 / 115 transversal does not allow the creation of curling by heating up to the activation temperature.

[0111] The layer according to the invention may include, for example, predominantly continuous filaments with round cross-section, three-pointed cross-section and star cross-section etc. (Figure 1).

[0112] Continuous filaments can be, for example, multicomponent filaments, while the arrangement of the individual components in the cross-section of the filament can be represented by a core and sheath (concentric arrangement), sectors or other arrangements with the center of gravity of the component surfaces at a single location within the cross-section of the continuous filament (Figure 2).

[0113] Regardless of the theoretical foundations, we are convinced that the determining element for creating filaments with the required characteristics is a specific combination of two components. Firstly, it is preferable that the filament component from which the nonwoven structure is created and, for example, the core of this structure, includes polymer A1, which is capable of shrinking under specific conditions. During the filament formation process – particularly during the cooling and stretching stages – it is this polymer A1 that is able to change its state, which is desirable in relation to the future activation phase. Polymer A1 can, for example, initially be in a semi-stable state (e.g., in a state with the lowest possible energy currently without continuous crystallization), after which it heats up during the activation phase and then cools slowly to change state. Petition 870220076974, dated 08 / 26 / 2022, page 54 / 144 44 / 115 semi-stable mentioned for another different, more stable state (for example, for a state corresponding to a different lower volume crystallization phase). This change results in the generation of internal forces causing shrinkage, where we assume that its vector is directed in the direction of the filament's median curve.

[0114] The diameters of the filaments in nonwoven fabric produced using the spunmelt method are in the millimeter and / or submillimeter range, while these filaments generally have an omnidirectional orientation (see Figure 3) and touch each other in such a way that the free sections between them have a size that is also in the millimeter and / or submillimeter range. The mutual cohesion between the filaments acts against the internal force vectors and thus forms the respective first point of resistance. This point of resistance can also be referred to as the limit point of resistance against structural shrinkage. If, for example, a filament is in the correct state and undergoes activation, it can create, for example, an irregular arc or wavy sections that extend in all 3 dimensions. A filament that is constrained by the surrounding structure formed by adjacent filaments, in contrast, does not possess such a degree of freedom.

[0115] According to the invention, the layer is formed using two-component filaments, while the second component includes polymer B, which has a lower melting temperature and preferably also provides other necessary characteristics, such as softness, providing a more pleasant touch and feel, etc. Polymer material A1 and polymer material B1 must have Petition 870220076974, dated 08 / 26 / 2022, page 55 / 144 45 / 115 mutually different characteristics related to shrinkage, meaning that in the preferred configuration, polymeric material B (which is preferably the material forming the filament sheath) may have less contractility (shrinkage) than polymeric material A (which is preferably the material forming the filament core). The result is the generation of different shrinkage forces acting within the two polymeric materials in mutual contact. Regardless of the theoretical foundations, we are convinced that polymeric material A and polymeric material B will always have different characteristics, meaning that the vectors of the internal forces causing shrinkage are never equal at the same point in time. This lack of homogeneity of forces allows the creation of a second limit point of resistance against shrinkage.This point of resistance can also be referred to as the limit point of resistance against filament shrinkage.

[0116] Regardless of the theoretical foundations, we are convinced that this specified displacement regularity is the main reason for the regularity of the curling of the free sections of the individual filaments. On the other hand, according to this invention, also regardless of the theoretical foundations, in the case of filaments that have a cross-section that does not support curling, the internal force vectors that cause curling in the first and second components do not provide the possibility of regular mutual displacement, the result of which is that such a filament creates irregular arcs or wavy sections in arbitrary directions. With substantial Petition 870220076974, dated 08 / 26 / 2022, page 56 / 144 46 / 115 simplifications it is possible to state that a filament does not have a regular propensity to bend in the direction of a specific part of its cross-section or perimeter, which results in its final irregular shape. After activation, the cross-section of such a filament remains essentially in a state that does not support curling, see Figure 4.

[0117] Regardless of the theoretical foundations, we are convinced that if the internal force causing shrinkage is small and therefore unable to overcome the counter-oriented forces corresponding to the limit point of filament resistance, the fabric remains unchanged. If, however, the internal forces causing shrinkage are sufficiently large and therefore able to overcome all the directional forces corresponding to the resistance points in the MD / CD directions, the fabric shrinks according to the MD / CD ratio and creates a flat structure.If the internal force causing shrinkage is specifically of sufficient magnitude to overcome the yield strength of the filaments against shrinkage, but not of sufficient magnitude to overcome the yield strength of the structure in the MD / CD directions, such that the least structural strength is predominantly oriented in the Z direction, the fabric will create the desired bulky structure. To one skilled in the art, it will be evident that the internal force required for shrinkage will be greater than the internal yield strength of the filament, but not less than the yield strength of the structure in the MD / CD directions. Petition 870220076974, dated 08 / 26 / 2022, page 57 / 144 47 / 115

[0118] The first layer (T) of the invention comprises a large number of filaments between which many points of mutual contact are formed. When observing this layer on the millimeter and / or submillimeter scale, it is noticeable that the filaments, or more precisely millimeter and / or submillimeter parts of the filaments, possess, as a result of the action of the adjacent filaments, a unique state, where they are exposed to the effects of a unique combination of forces created during activation, which allows the production of an exceptionally wide diversity of filament shapes in the final structure. In the plane of the MD / CD directions, it may seem a contradiction that, on the contrary, the filaments remain in an almost perfectly flat level state. On the other hand, however, the filament can move "up" and "down" and create an extensive 3D structure encompassing all directions, which are the MD, CD, and Z directions. According to this invention, and regardless of the theoretical foundations, we are convinced that the great diversity of directions of the continuous filaments in the layer provides an advantage in terms of the final characteristics. According to the invention, the layer is homogeneous on a macroscopic scale. The great diversity of filament shapes contained in a layer, combined with the mutual interaction of these filaments, allows for an advantage of this invention, consisting mainly in that the layer is able to respond in the necessary way to the action of external effects (for example, pressure and its release or the effects of a liquid passing through it).

[0119] With substantial simplification, it is also possible to express the directional arrangement of the filaments by Petition 870220076974, dated 08 / 26 / 2022, page 58 / 144 48 / 115 is the middle of the ratio between the "length of the filaments and the length of the fabric".

[0120] An M or T layer produced in this way with a non-compatible crimping cross-section contains - at least 20% of filaments with a “filament length to fabric length” ratio greater than 1.2, preferably at least 30% of filaments with a “filament length to fabric length” ratio greater than 1.2, preferably at least 40% of filaments with a “filament length to fabric length” ratio greater than 1.2, preferably at least 50% of filaments with a “filament length to fabric length” ratio greater than 1.2; - at least 10% of filaments with a “filament length to fabric length” ratio greater than 1.5, preferably at least 15% of filaments with a “filament length to fabric length” ratio greater than 1.5, preferably at least 20% of filaments with a “filament length to fabric length” ratio greater than 1.5, preferably at least 25% of filaments with a “filament length to fabric length” ratio greater than 1.5, preferably at least 30% of filaments with a “filament length to fabric length” ratio greater than 1.5; Petition 870220076974, dated 08 / 26 / 2022, page 59 / 144 49 / 115 - at least 5% of filaments with a “filament length to fabric length” ratio greater than 2, preferably at least 10% of filaments with a “filament length to fabric length” ratio greater than 2, preferably at least 15% of filaments with a “filament length to fabric length” ratio greater than 2, preferably at least 20% of filaments with a “filament length to fabric length” ratio greater than 2.

[0121] A layer, M or T, produced in this way with a cross-section not compatible with crimping contains simultaneously: - at least 10% of filaments with a “filament length to fabric length” ratio of less than 2.5, preferably at least 20% of filaments with a “filament length to fabric length” ratio of less than 2.5, preferably at least 30% of filaments with a “filament length to fabric length” ratio of less than 2.5, preferably at least 40% of filaments with a “filament length to fabric length” ratio of less than 2.5, preferably at least 50% of filaments with a “filament length to fabric length” ratio of less than 2.5; - at least 5% of filaments with a ratio “between filament length and fabric length” Petition 870220076974, dated 08 / 26 / 2022, page 60 / 144 50 / 115 less than 2, preferably at least 10% of filaments with a “filament length to fabric length” ratio of less than 2, preferably at least 15% of filaments with a “filament length to fabric length” ratio of less than 2, preferably at least 20% of filaments with a “filament length to fabric length” ratio of less than 2.

[0122] For the material according to the invention, it may be advantageous that the first layer T, alternatively both layers M and T, contain continuous filaments with a crimp-supporting cross-section (Figure 5). These may be multicomponent, preferably bicomponent. Regardless of the theoretical background, we are convinced that the crimp is supported by such cross-sections, where the center of gravity of the surfaces created by one component arranged in the cross-section of the filaments is located at a distance from the center of gravity of the surfaces of the other component.

[0123] In the field of technical knowledge, it is well known that a certain combination of polymers with different levels of shrinkage, which are arranged in the so-called cross-section allowing formation by means of crimping, allows the so-called crimping to be achieved. At the same time, this can be immediate spontaneous crimping or latent crimping, the prerequisite of which is prior activation (e.g., thermal activation). Filaments with cross-sections that allow formation by crimping provide wavy sections. Petition 870220076974, dated 08 / 26 / 2022, page 61 / 144 51 / 115 regular creating what is called helical crimping. With substantial simplifications, it is possible to state that a filament with a cross-section that allows crimping tends to bend in the direction of the component with the greater degree of shrinkage, which creates irregular helical crimping. In other words, this means that the cross-section that allows crimping causes regular mutual displacement of internal force vectors acting on the first and second components towards each other.

[0124] The filament layer may include, for example, predominantly continuous filaments with round cross-section, three-pointed cross-section and star cross-section, etc. (Figure 1). Crimping can be achieved, for example, in component arrangements in cross-section types such as side-by-side, eccentric core / sheath and others.

[0125] Similarly to the previous case, here too, during the filament formation process, particularly during the cooling and stretching stages, polymer A is able to change its state, which is desirable in relation to the future activation phase. Polymer A may, for example, initially be in a semi-stable state (e.g., in a state with the lowest possible energy without continuous crystallization), after which it heats up during the activation phase and then cools slowly to change the aforementioned semi-stable state to another, more stable state (e.g., to a state corresponding to a different lower volume crystallization phase). This change results in the creation of forces Petition 870220076974, dated 08 / 26 / 2022, page 62 / 144 52 / 115 internal forces causing shrinkage, where we assume that its vector is directed in the direction of the median curve of the filament component. A change in the volume of polymer A in the case of filaments with a cross-section supporting curling causes the intensification of internal forces in the filament (an increase in vector forces displaced relative to each other) and thus, with high probability, the radius of the created arcs is reduced; in the case of a layer of filaments, this results in a certain contraction of the entire structure (= shrinkage).

[0126] Although filaments with crimp-supporting cross-sections have a propensity for creating regular shapes, specifically helical shapes, while this characteristic of said filaments relates namely to their propensity for regular bending towards the side of the filament that includes the material with the greatest shrinkage, these filaments in the layer are concomitantly constrained by their respective adjacent filaments which prevent them from maintaining a regular helix. Regardless of the theoretical foundations, we are convinced that the greater the force that causes shrinkage before the deposition of the filaments on the belt, the greater the degree of crimping per unit length of the filaments, which is the reason for the existence of the greater number of helical parts located within the fibrous structure.If, on the other hand, the level of curling is lower, for example, less than 25 twists per inch (each individual loop is located more than 1 mm along the length of the formed helix), then the free space between the filament contact points begins to decrease. Petition 870220076974, dated 08 / 26 / 2022, page 63 / 144 53 / 115 becomes insufficient to hold even a part of the helix, while the inversely oriented forces caused by the mutual contact of the filaments increase proportionally to the magnitude. When the number of twists per inch is less than 15 (i.e., in the case where each individual loop is located more than 2 mm from the length of the formed helix) it becomes difficult to differentiate the parts of the helices, and when the number of twists per inch is less than 10 (i.e., in the case where each individual loop is located more than 2.5 mm from the length of the formed helix) the constant forces acting on the filament are completely overcome by inversely oriented forces acting against the regular mutual displacement of the vectors of the internal shrinkage forces, which allow the formation of regular curling, as a result of which the structure acquires a completely irregular appearance.A person skilled in the art will, however, be aware of the fact that there are also several other factors that support the formation of a bulky structure caused by the regular mutual displacement of internal shrinkage force vectors (in the case of filaments with a cross-section that supports crimping) and the formation of a bulky structure caused by the irregular shrinkage of the filaments (in the case of filaments with a cross-section that does not support crimping). Examples of differences in structure, which are based on the crimping of synthetic silk filaments, are shown in Figure 6 (although they are described in the article "Fiber Crimp Distribution in Nonwoven Structure" by Kunal Singh, Mrinal Singh and published in 2013 (available at http: / / article.sapub.org / 10.5923.j.fs.20130301.03.html). Petition 870220076974, dated 08 / 26 / 2022, page 64 / 144 54 / 115

[0127] During the thermal activation of the structure, the volume of polymer A is reduced, thus resulting in the so-called shrinkage of the entire structure. For the material according to the invention, it may be advantageous that the first layer T, alternatively both layers M and T, which are subjected to activation, achieve a degree of shrinkage not exceeding 20% ​​in the CD or MD direction, preferably not more than 15%, preferably not more than 13%, more preferably not more than 11%, more preferably not more than 9%. The degree of shrinkage of both layers may be different.

[0128] For one of the solutions according to the invention, it is advantageous when the first layer T, which exhibits shrinkage, is combined with a second layer M, which does not exhibit shrinkage. For this material according to the invention, it may be advantageous that in the first layer T, which is subjected to activation in the CD or MD direction, the degree of shrinkage achieved is not greater than 20%, preferably not greater than 15%, preferably not more than 13%, preferably not more than 11%, most preferably not more than 9%.

[0129] In one of the advantageous solutions according to the invention, where the first layer (T) utilizes the shrinkage of a polymer (in the crimped and non-crimped version) is preferably created from two-component core / sheath type filaments having a circular or three-pointed cross-sectional shape.

[0130] The continuous filaments contained in this first T layer are formed by two or more components. The first component can be selected, for example, from the group that includes polyesters (e.g., polyesters Petition 870220076974, dated 08 / 26 / 2022, p. 65 / 144 55 / 115 aromatics, which include polyethylene terephthalate (PET) or aliphatic polyesters, which include polylactic acid (PLA), polyamides, polyurethanes or their copolymers, or alternatively suitable mixtures. The scope of the invention includes the suit wherein the first component comprises or essentially comprises a plastic selected from a group of polyesters, which also includes polyester copolymers (coPET) or polylactic acid copolymers (COPLA). The polyester that is preferably used is polyethylene terephthalate (PET) or polylactic acid (PLA).

[0131] The second component B1 can be selected, for example, from the group that includes polyolefins (i.e., polypropylene or polyethylene), low-melting-point polymers, or alternatively, suitable copolymers or polymer blends. The scope of the invention includes the fact that the second component comprises, or essentially comprises, a plastic selected from a group of polyesters, which also includes polyester copolymers (coPET) or polylactic acid copolymers (COPLA). The polyolefin preferably used is polyethylene (PE).

[0132] The preferred combinations of A / B components selected for bicomponent filaments in the nonwoven layer according to the invention are PET / PE, PET / PP, PET / CoPET, PLA / COPLA, PLA / PE and PLA / PP combinations.

[0133] In the case of two-component filaments with a crimp support cross-section, it is a necessary condition to use a combination of polymers that in the given crimp combination, or possibly to use, for example, nucleating agents or other crimp support additives. Petition 870220076974, dated 08 / 26 / 2022, page 66 / 144 56 / 115

[0134] The preferred configuration of two-component filaments is a weight ratio between the first component A1 and the second component B1 in the range of 50:50 to 90:10.

[0135] Alternatively, the component configuration may also contain additives intended to modify the characteristics of continuous filaments. For example, the core may contain a colored pigment or a curling agent. In the published literature in the field of technology, it is possible to identify several special combinations of curling agents, which to some extent are capable of altering the behavior of polymers during crystallization and shrinkage (as shown, for example, by the author Gajanan in US patent 5753736 which was filed in 1995). Conversely, for example, common titanium dioxide, which is often used as an additive to obtain a higher degree of whiteness, will cause only an insignificant change in the behavior of the polymer, which can be compensated for by slightly adapting the process conditions if necessary.

[0136] The sheath may, for example, contain a color pigment or surfactant (intended, for example, to obtain a silky touch and feel property). To one skilled in the art it will be evident that there are many other possibilities derived from the requirements of specific applications of use.

[0137] In another configuration, the components may also contain a number of different polymers. A configuration is thus possible, for example, where the first component (e.g., core) Petition 870220076974, dated 08 / 26 / 2022, page 67 / 144 57 / 115 contains a certain proportion of the polymer or polymers that form the second component (e.g., sheath) or where, conversely, the second component (e.g., sheath) contains a certain proportion of a polymer or polymers that form the first component (e.g., core). In the published literature, it is possible to determine a certain content level by which it is possible to obtain an exact combination of polymers. For example, the author Moore states (in patent application US2012088424 filed by 3M Innovative Properties) that a mixture of up to 10% polypropylene with polyester will provide filaments with stable properties.

[0138] In combination with this first layer (T) exhibiting a certain level of shrinkage, it is advantageous that the second layer (M) contains filaments with a lower or no shrinkage level. In this case, significantly lower or no forces induced by the activation of the filament layer are exerted on the second layer (M) itself. Concomitantly, by the effect of layer adhesion, or possibly by the effect of the formation of bonding points between the layers, this second layer (M) is forced to change its arrangement in space (forced shrinkage) by the effect of the shrinkage of the first layer (T). Thus, external forces are exerted that force the filaments in the structure to change their position. Without wanting to be limited by theory, it is believed that the filaments or their parts orient themselves more in the ze direction, thus increasing the thickness of the nonwoven fabric.In advantageous cases, the increase in tissue thickness is greater than the forced shrinkage in the MD and CD directions, and therefore this leads to a... Petition 870220076974, dated 08 / 26 / 2022, p. 68 / 144 58 / 115 increase in the total volume of the layer and therefore also an increase in the volume of the tissue.

[0139] The combination of a shrink- and non-shrink layer bonded by means of a calender roll at bonding points, or better described as by means of flat consolidation reliefs, which compact the filaments into a bonding relief and join them locally by thermal effects, is well known in the industry. The structure is subsequently activated by means of thermal flow (e.g., hot air), the shrink layer shrinks and forces the non-shrink layer to arch into cushions between the bonding points (see, for example, patent application EP3192910 filed by Reifenhauser GmbH & Co. KG Maschinenfabrik).

[0140] The nonwoven fabric according to the invention has a different structure. While in the case of the aforementioned patent application the fabric's strength is fundamentally given by the regular arrangement of the bonding reliefs and the activation is controlled in order to avoid greater filament bonding (since greater bonding would increase the stiffness and reduce the fabric's malleability), the nonwoven fabric according to our invention undergoes activation of component A1, which is capable of shrinking at a temperature corresponding to the bonding temperature of components B. The fabric according to the invention is not interconnected by regularly arranged local bonding reliefs along the fabric's surface plane (given by the arrangement of the reliefs on the calender roll), but rather interconnected within the entire volume of the nonwoven fabric, where essentially each filament intersection forms a Petition 870220076974, dated 08 / 26 / 2022, p. 69 / 144 59 / 115 point of connection that consolidates the fabric. The fabric according to the invention does not contain connection reliefs and arched pads of free filament sections between them. On the contrary, its thickness is essentially homogeneous and the free filament sections are much shorter (from one filament intersection to the next). At the same time, the absence of fixed connection reliefs allows, during the activation period, a certain degree of freedom of movement for the individual filaments in both layers. At the same time, it is generally applied that connection with a calender and therefore the creation of connection reliefs alters the shape of the relief filament plane and flattens them completely.In the case of two-component filaments, not only does it melt the component with the lower melting point, but it also mechanically and thermally stresses the component with the higher melting point (e.g., flattening it in the relief plane) and creates weak points (e.g., the transition between the relief and the free part of the filament). Without wanting to be limited by theory, we assume that it is precisely the combination of limited stress in the component with the higher melting point (A) together with a degree of freedom of movement during the forced activation process and instantaneous fixation of the structure through the hardening of the bonding component that allows the creation of a highly voluminous fabric structure, while supporting recovery and exhibiting the softness and compressibility typical of the second layer M.

[0141] Figures 7A, 7B show the differences in the structure of the nonwoven fabric bonded using V-bonding reliefs (Figure 7A) and the structure bonded using flow. Petition 870220076974, dated 08 / 26 / 2022, pp. 70 / 144 60 / 115 heat for the creation of B-connection points throughout the volume (Figure 7B).

[0142] In general, it applies that a nonwoven fabric bonded using a calender contains bonding reliefs spaced in millimeters (typically 3-20 mm) and this distance also defines the free filament sections (typically 3-30 mm). The fabric according to the invention is thermally bonded by heat flow throughout its volume and contains bonding points at spacings, depending on the volume of the structure, of approximately 0.3 to 8 mm of free filament sections. In both cases, it applies that the lower limit is more typical for finer filaments and the upper limit for thicker filaments. The typical limits described represent the average length of a free filament section in the structure.

[0143] A second forcibly shrunk M layer can create a homogeneous layer with a regular arrangement of filaments, as can be seen, for example, in Figure 8. It can also create a structure with varying degrees of local filament bending in the M layer, as can be seen in Figure 9, or even locally irregularly create a bulge in a bundle of filaments, as can be seen in Figure 10.

[0144] By properly configuring the process conditions, particularly process temperatures and stretching forces during the exposure of the fabric to heat flow and subsequent heating, it is thus possible to support and / or limit the creation of non-homogeneous shapes and bulges. For example, it is possible to create an irregular bulge structure as can be seen in Figure 11. Petition 870220076974, dated 08 / 26 / 2022, p. 71 / 144 61 / 115 Examples

[0145] The recommended embodiment of the invention is thus characterized by at least two nonwoven layers. One advantageous embodiment is a nonwoven fabric according to the invention created by interlocking at least two M and T layers of filaments produced by the spunbond method (continuous spinning). The nonwoven fabric may also be composed of multiple layers, where at least one layer represents the first T layer and another layer represents the second M layer, and the fabric also contains another X layer. The X layer may consist, for example, of a layer of meltblown filaments (obtained via blowing), or a layer of staple fibers, etc.

[0146] In the recommended embodiment of the invention, there are multicomponent or bicomponent filaments, from which the T or M layer of the nonwoven fabric is constituted, made by spinning in a spinneret or using a spinneret, and subsequently preferably passing through a cooler. Inside this cooler, the filaments are generally cooled by means of a fluid medium, mainly by means of cooling air. The scope of the invention encompasses the fact that the spun filaments subsequently also pass through a stretching mechanism in which they are processed by stretching. The stretched (extended) filaments are then deposited on a moving belt, where they form a layer of filaments. In one of the advantageous configurations, by adjusting specific parameters that determine the stretching rate, it is then possible to create filaments in the layer that have a controlled degree of potential shrinkage. Petition 870220076974, dated 08 / 26 / 2022, page 72 / 144 62 / 115

[0147] According to the preferred embodiment of this invention, a diffuser inserted as a deposition mechanism will be used, which controls the deposition of filaments and is installed between the stretching mechanism and the filament deposition location. The scope of the invention encompasses the use of at least one diffuser, whose opposite side walls diverge from each other in relation to the direction of filament passage. A highly recommended embodiment of the invention is characterized by the fact that the drive unit of the cooling mechanism and the extraction mechanism is designed as a closed system. Within this closed system, no additional air source is used, which would supplement the supply of external cooling media or cooling air for the cooling mechanism. Such a closed system has proven to be particularly suitable in the production of nonwoven fabrics.

[0148] In the case of the production of nonwoven fabrics according to the invention using shrinkage, it has been found that the technical solution according to this invention, which eliminates the problem associated with filament shrinkage, is particularly reliable in functional terms and effectively feasible when said closed unit is used, particularly when, in addition to the especially preferred configuration form, a diffuser is also used, which is disposed between the stretching mechanism and the filament deposition location. It has already been stated that the shrinkage of a nonwoven belt that is produced by means of the spunbond (continuous spinning) method can be adapted or regulated very specifically by means of the parameters of Petition 870220076974, dated 08 / 26 / 2022, page 73 / 144 63 / 115 stretch ratio, cooling air / polymer ratio, and filament speed.

[0149] From the definition already presented, it is evident that production using the spunbond (continuous spinning) method consists of the direct conversion of polymers into filaments, which are subsequently randomly spread at the deposition site with the aim of creating a nonwoven layer composed of these filaments. The spunbond (continuous spinning) method determines both the characteristics of the individual filaments and the characteristics of the final nonwoven fabric. The final nonwoven fabric produced cannot always be used to determine the various characteristics and conditions of the individual filaments, such as rheological characteristics, structural characteristics of the polymers, and shrinkage, which occur during the individual production steps of this nonwoven fabric.The potential shrinkage of a nonwoven fabric generally determines its ability to create a bulky nonwoven fabric, which is achieved by using the shrinkage of individual filaments to obtain an increased relative thickness of the filament layer. This occurs, however, without the decomposition of the fabric structure and / or without significant changes in the length and width of the filament layer. The scope of the invention includes the fact that the shrinkage of the filaments is defined by using various raw materials contained in the composition of the filaments and / or by defining different material processing conditions during the production of the filaments for the woven nonwoven fabric and / or by using different cross-sectional shapes of the filaments and / or. Petition 870220076974, dated 08 / 26 / 2022, pp. 74 / 144 64 / 115 through adjusting the mass ratio between the various input materials and / or through defining different filament orientations.

[0150] The recommended embodiment of the invention does not differentiate between filaments with cross-sections that support crimping and filaments with cross-sections that do not support crimping. Both types can be used advantageously for certain applications. Similarly, a suitable combination can be created using layers of crimped and non-crimped filaments. To a person with professional qualifications in the field of technology, it will be evident that there are technological advantages provided by filaments with cross-sections that do not support crimping as opposed to crimped filaments in obtaining bulky and soft materials. Unlike filaments with cross-sections that do not support crimping, when processing filaments in which (spontaneous) crimping occurs during production, it is not easy to control the course of the production process.In most types of filaments whose cross-sections allow for crimping, crimping is created during the deposition and / or activation phase. Since the filaments move relative to each other during the crimping process, it is easy for them to come into contact or become entangled, which in other words means they can cause mutual interference. In nonwoven layers consisting of filaments with spontaneous crimping capacity, there are often limitations related to their shape and arrangement due to distribution. Petition 870220076974, dated 08 / 26 / 2022, pp. 75 / 144 65 / 115 uneven filament position caused by their mutual movement. The essential subsequent measures required due to these limitations generally include reducing the quantity processed, slowing down the production process, and including additional special steps in the production process designed to safely define the relative positions of the filaments.

[0151] In filaments that do not undergo spontaneous curling during the spinning, cooling and stretching process, it is possible to obtain a much more uniform deposition of filaments in the layer, which allows the use of the lowest possible basic weight, maintaining the necessary properties of the fabric and / or at the same time establishing higher production line speeds and therefore also a greater quantity of processed material. It is thus much easier to control the course of the production process and in the case of a cross-section that does not tolerate curling, it is also possible to use spinnerets and spinning bundles produced more cheaply.

[0152] The advantageous configuration of the invention also includes the fact that the resulting filament layer is thermally pre-consolidated, i.e., it is pre-consolidated and contains thermally formed bonds. One of the advantageous configurations of the invention is also the fact that the resulting nonwoven fabric is thermally activated in order to obtain controlled shrinkage of at least one of the layers. The consolidation and eventual thermal activation is preferably carried out by means of at least one of the effects, which are contact with a flow of hot medium (for example, by means of hot air or infrared radiation) Petition 870220076974, dated 08 / 26 / 2022, page 76 / 144 66 / 115 and / or contact with a hot surface. An example of such a hot surface could be primarily a part of a roll. It is desirable that thermal activation be performed under a condition where shrinkage occurs uniformly across the entire surface of the fibrous layer. Thermal activation can be performed in a chamber where hot air is supplied, or by means of the filament layer passing through an oven. It is also possible to perform thermal activation and consolidation by means of infrared or ultraviolet light, transmitted microwaves and / or laser radiation. It is necessary to emphasize that within the scope of this described procedure performed “on the production line”, thermal consolidation can also occur immediately after the completion of the previous stages of the production procedure, or both stages of the procedure, which are thermal activation and consolidation, can be performed “off the production line”, i.e., separately from the previous stages of the production process.Thermal activation can therefore be carried out essentially "off the production line," that is, at a different time and place.

[0153] For the solution according to the invention, it is advantageous that the flow of hot media passes through the fabric and thus results in heat transfer throughout the entire volume of the nonwoven fabric.

[0154] The required level of pre-consolidation of the fibrous tissue / filament layer largely depends on the conditions of the production process. The decisive prerequisite is to correctly define the level of mutual cohesion of the filaments within the filament layer and, therefore, also the possibility of controlling the level of mutual cohesion of the filaments based on the requirements of the subsequent stage of Petition 870220076974, dated 08 / 26 / 2022, page 77 / 144 67 / 115 production process. In the case where the production process is carried out on the production line with activation performed on the belt itself, the required level of cohesion is relatively low, as it is only necessary to prevent fraying or thinning caused by significant undesirable movements during the activation process. In special cases, for example, when the filaments themselves provide very good cohesion during contact with each other or with their base, which is made possible, for example, by the shape of their cross-section, interlacing speed or the composition of the material, the cohesion characteristics of the filament layers may be sufficiently good even without thermal pre-consolidation.In other cases, for example, when the production process is divided into two stages or when the filament layer is pre-consolidated before full activation and transferred, for example, in the form of rolls, the required level of cohesion will be much higher, which also results in the need for a much higher level of pre-consolidation.

[0155] The activation temperature must be in the range between the glass transition temperature and the softening temperature (Vicat softening temperature according to ISO DIN 306) of component(s) A.

[0156] In one advantageous configuration, the invention provides bulky nonwoven fabrics created using filaments with an adapted or controlled shrinkage of these filaments. The shrinkage occurs uniformly throughout the filament layer, thanks to which the procedure should provide uniform nonwoven fabric properties, which ensure uniformly controlled shrinkage. Petition 870220076974, dated 08 / 26 / 2022, page 78 / 144 68 / 115

[0157] Inside the convection cooler, the filaments are generally cooled by means of a circulating fluid, mainly by means of cooling air. As stated above, it is necessary that the potential shrinkage of the filaments be uniformly distributed throughout the length, width, and thickness range of the layer exhibiting shrinkage. The characteristics related to shrinkage can be modified by adapting the stretch ratio, cooling air / polymer ratio, and filament speed, whereas, according to the invention, these parameters are practically uniform for each individual filament.

[0158] The scope of the invention includes the fact that the created nonwoven fabric consists of several layers, of which at least one first layer T, alternatively at least one first layer T and a second layer M, alternatively each of the layers forming the nonwoven fabric is preferably created by means of the spunbond method (continuous spinning) in a spinning beam (1). At the same time, it is obvious that several layers are deposited on top of each other and subsequently these layers are transferred together to at least one molding belt (2) for the mechanism (3) for final consolidation.

[0159] The filaments (4) are created by spinning in a spinneret (5). The arrangement of the filaments can be optimized by their alternating placement, whereby a condition can be achieved where each of the individual filaments has a very similar weight and is supplied with cooling air of very similar temperature. The spinnerets can have various numbers of capillaries and also Petition 870220076974, dated 08 / 26 / 2022, page 79 / 144 69 / 115 variable diameters (d) and lengths (l) of these capillaries. The length (l) is, as a rule, calculated as a multiple of the capillary diameter and for this application area is selected in the range of 2 to 10 l / d. The number of capillaries needs to be selected based on the required final filament diameter and the total amount of polymer processed required or planned, along with the required filament spinning speed. The number of capillaries can vary in the range of 800 to 7,000 capillaries per meter, making it possible to obtain filaments with diameters in the range of 8 to 45 µm. The capillary diameter and filament speed are selected to allow achieving the correct level of potential shrinkage of the final filament.The filament speed should be set in the range of 1000 to 10000 m / min for filaments with a cross-section that does not tolerate curling and exhibits shrinkage in the range of 3000 to 5500 m / min, and the capillary diameter should be selected in the range of 200 to 1000 µm, which allows obtaining an adequate process extraction rate in the range of 200 to 1300 in the case of circular capillaries, while to achieve the necessary level of production line productivity, in the case of these capillary circuits, it is more advantageous to have a stretch ratio in the range of 300 to 800. Non-circular capillaries, as a rule, exhibit higher stretch ratio values, which are largely dependent on the shape of the capillary and the relative ratio of its surface area to volume. The volume and temperature of the cooling air are adjusted to allow for the correct extraction rate and cooling conditions.It has been found that with regard to this invention, it is useful when the reason for... Petition 870220076974, dated 08 / 26 / 2022, pp. 80 / 144 70 / 115 The cooling air volume for the spun polymer is in the range of 20:1 to 45:1. The volume and temperature of the cooling air are controlled in the cooler (6). This temperature can be adjusted in the range of 10°C to 90°C, preferably in the range of 15°C to 80°C, so that the cooling conditions can be used in specific cases to control the shrinkage course. The cooling conditions determine how quickly the filaments cool from the melting temperature to the glass transition temperature during the spinning process. For example, setting a higher cooling air temperature results in delayed cooling of the filaments. In practice, for the purposes of this invention, achieving the necessary and usable cooling air temperature range is easier when the cooler is divided into 2 zones in which the temperature range can be controlled separately.In the first zone (6a), which is located in the vicinity of the spinneret, the temperature can be adjusted in the range of 10°C to 90°C, preferably in the range of 15°C to 80°C and more preferably in the range of 15°C to 70°C. In the second zone (6b), located in the immediate vicinity of the first zone, the temperature can be adjusted in the range of 10°C to 80°C, preferably in the range of 15°C to 70°C and more preferably in the range of 15°C to 45°C.

[0160] Next, the filaments are guided through the stretching zone (7). Here the filaments are pulled by stretching forces created by the effect of the cooling air velocity. The volume of cooling air and the adjustable geometry of the stretching zone allow a certain air velocity to be achieved, which is Petition 870220076974, dated 08 / 26 / 2022, pp. 81 / 144 71 / 115 subsequently transferred to the filament speed. This filament speed, along with the amount of polymer processed, then defines the filament diameter. The shrinkage / contraction potential is regulated by the filament speed, the stretch ratio, and the cooling air / polymer ratio.

[0161] In the next step, the filaments are introduced into the diffuser (8), whose opposite walls diverge from each other in relation to the direction of filament movement. The positions of these walls can be adjusted in order to obtain nonwoven fabrics with a uniform composition, on which the individually deposited filaments form an arrangement that presents an omnidirectional orientation in the MD / CD plane.

[0162] Simultaneously, it is evident that the deposited filament layer is affected by the air, by the effect of which these filaments are fed into the diffuser. The airflow can be adapted to create various arrangements, from clearly zigzag filament depositions to truly circular loops and even further, similarly, elliptical structures oriented in the CD direction. The filaments are deposited on a forming belt and transported to at least one mechanism (9) for pre-consolidation. Cooling air flows through the deposited filament layer and through the forming belt and is subsequently channeled away from the processing area. The volume of aspirated air can be adjusted to facilitate filament deposition and, likewise, ensure effective contact of the filament layer with the forming belt. The pre-consolidation mechanism is Petition 870220076974, dated 08 / 26 / 2022, page 82 / 144 72 / 115 located near the diffuser. The formation of the filament layer is controlled by means of air drawn in along the entire path between the diffuser and the pre-consolidation mechanism. Pre-consolidation of the filament layer is carried out by means of hot air.

[0163] The amount of energy transferred to the filament layer is controlled by a method that allows the filaments to be softened or perfused only to a certain degree, which ensures good cohesion between the individual filaments. After the necessary cohesion between the filaments is achieved, the fibrous layer can be transported to the forming belt without additional assistance from any auxiliary mechanism and without affecting or risking destruction / damage from the effect of forces that arise during this transport. This pre-consolidation procedure is also sufficient to move the filament layer to a different deposition zone in a production line composed of several spinning beams. The energy transferred to the filaments is not sufficient to activate the shrinkage of these filaments.

[0164] The method according to the invention includes determining the equilibrium between the preconsolidation parameters: preconsolidation temperature, preconsolidation air velocity and preconsolidation time. Preconsolidation time is understood to be the time during which the filament layer is modified by the preconsolidation air.

[0165] It is recommended that the filament layer pre-consolidation time be in the range of 1 to 10000 ms, Petition 870220076974, dated 08 / 26 / 2022, page 83 / 144 73 / 115 preferably in the range of 2 to 1000 ms and more preferably in the range of 4 to 200 ms.

[0166] The pre-consolidation air velocity used in this pre-consolidation unit is set in the range of 0.1 to 10 m / s, preferably in the range of 0.8 to 4 m / s. It is recommended that the consolidation temperature during pre-consolidation be in the range of 80°C to 200°C, preferably in the range of 100°C to 180°C. In one embodiment, this pre-consolidation temperature is in the range of 90°C to 150°C, mainly 110°C to 140°C.

[0167] According to various advantageous configuration forms, nonwoven fabric includes a layer of two-component filaments: - a component (A) produced from polyethylene terephthalate (PET) and the second component (B) produced from a polyolefin, particularly polyethylene or polypropylene, while the pre-consolidation temperature is preferably in the range of 110°C to 160°C, especially 120°C to 150°C; - a component (A) produced from polyethylene terephthalate (PET) and the second component (B) produced from a copolymer of polyethylene terephthalate (CoPET), while the pre-consolidation temperature is preferably in the range of 110°C to 180°C; - a component (A) produced from polylactic acid (PLA) and the second component (B) produced from a polyolefin, particularly polyethylene or polypropylene, Petition 870220076974, dated 08 / 26 / 2022, p. 84 / 144 74 / 115 while the pre-compaction temperature is preferably in the range of 80°C to 130°C; - a component (A) produced from polypropylene (PP) and the second component (B) produced from a polyolefin, particularly polyethylene or a copolymer of polyethylene and polypropylene, the preconsolidation temperature is preferably in the range of 80°C to 130°C.

[0168] In one of the advantageous configurations in the production line area, which is arranged after the diffuser, a layer of filaments is conveyed to at least one activation unit (10). The filaments are activated by means of hot air. At the same time, it is understandable that the actual shrinkage of the filament shrinking component is a function of the temperature of the filament shrinking component and, likewise, a function of the duration of time during which it is subjected to the effects of temperature. Furthermore, it is evident that the speed of the shrinking process also depends on the temperature of the filament shrinking component. Based on this invention, the course of the process is controlled by a method consisting of a slow start of shrinkage, thanks to which the forces that are created inside the layer as a result of this shrinkage are smaller than the cohesive forces between the filaments.The result that can be achieved by this process control is to obtain a cohesive and uniform structure of a nonwoven fabric with a reduced density of the filament structure, which also leads to an increase in the thickness of this nonwoven fabric. Petition 870220076974, dated 08 / 26 / 2022, page 85 / 144 75 / 115

[0169] According to one embodiment of the invention, the execution of the steps of the preconsolidation and activation method, during which the preconsolidation and / or activation time, the air velocity required for preconsolidation and / or activation, and the preconsolidation and activation temperature are controlled by means of a combined method in a combined mechanism for preconsolidation and activation.

[0170] One of the advantageous methods according to the invention includes determining the balance between the activation parameters: activation temperature, activation air velocity, and activation time. Activation time is understood to be the time during which the filament layer is modified by the activation air. It is evident that these parameters can be altered within the specified ranges in reaction to the potential shrinkage level of the filament and, similarly, with the aim of establishing the ideal combination between activation time, activation temperature, and activation air velocity.

[0171] It is recommended that the filament layer activation time be in the range of 20 to 5000 ms, preferably in the range of 30 to 3000 ms and more preferably in the range of 50 to 1000 ms.

[0172] The activation air velocity used in this activation unit is adjusted in the range of 0.1 to 2.5 m / s, preferably in the range of 0.3 to 1.5 m / s. It is recommended that the activation temperature during thermal activation be in the range of 80°C to 200°C, preferably in the range of 100°C to 160°C. In one of the embodiments, this Petition 870220076974, dated 08 / 26 / 2022, p. 86 / 144 The 76 / 115 activation temperature is in the range of 90°C to 140°C, mainly from 110°C to 130°C.

[0173] According to various advantageous configuration forms, nonwoven fabric includes a layer of two-component filaments: - a component (A) produced from polyethylene terephthalate (PET) and the second component (B) produced from a polyolefin, particularly polyethylene or polypropylene, wherein the activation temperature is preferably in the range of 90°C to 140°C, especially 100°C to 140°C; - one component (A) is produced from polyethylene terephthalate (PET) and the second component (B) is produced from a copolymer of polyethylene terephthalate (CoPET), while the activation temperature is preferably in the range of 120°C to 160°C; - a component (A) produced from polylactic acid (PLA) and the second component (B) produced from a polyolefin, particularly polyethylene or polypropylene, while the activation temperature is preferably in the range of 80°C to 140°C.

[0174] An advantageous configuration according to the invention includes the final consolidation procedure, which consists of modifying the filament layer using hot air in the consolidation mechanism (3). Within this consolidation mechanism, the filament layer is consolidated, while the layer may consist of a single layer or Petition 870220076974, dated 08 / 26 / 2022, p. 87 / 144 77 / 115 multiple layers with filaments bonded in this layer, respectively in these layers without concomitantly resulting in a significant reduction in the thickness of this filament layer and without a perceptible consolidation gradient existing throughout the thickness of the nonwoven fabric. It is evident that the residual thickness and elasticity of the nonwoven fabric are affected by the consolidation temperature, since this consolidation temperature must be sufficiently high to allow obtaining the necessary bonds between the filaments of the nonwoven fabric, but without softening or collapse of the processed filament layer. It is necessary that within the consolidation mechanism the consolidation temperature and the consolidation forces acting on the filament layer adapt to the required processing effect, which is a low level of softening and low internal forces.Simultaneously, however, it is necessary that the temperature and these forces be sufficiently high for the desired effect on the integrity of the filament layer for the production of nonwoven fabric. This can be achieved by means of several different devices, which include, for example, a consolidation mechanism with a bell-shaped drum, a consolidation mechanism with a flat belt, or a multi-drum consolidation mechanism.

[0175] The consolidated nonwoven fabric is in the final stage wound onto a reel (11). If it is necessary to modify the surface characteristics of the nonwoven fabric, for example, to obtain better fluid transmission or a greater capacity to drain them, the spraying mechanism or the immersion roller is located between the Petition 870220076974, dated 08 / 26 / 2022, page 88 / 144 78 / 115 moving belt and the end consolidation mechanism, or between the end consolidation mechanism and the reel.

[0176] One embodiment of the invention consists of combining the activation and consolidation steps together, where within the consolidation mechanism the activation time and / or consolidation time, the air velocity required for activation and / or consolidation, and the activation and / or consolidation temperature are controlled.

[0177] A fundamental element is determining the balance between the consolidation parameters: consolidation temperature, consolidation air velocity, and consolidation time. Consolidation time is understood to be the time during which the filament layer is modified by the consolidation air. It is evident that these parameters can be altered within the specified ranges in reaction to the potential consolidation level of the filament layer and, similarly, with the aim of achieving the ideal combination between consolidation time, consolidation temperature, and consolidation air velocity.

[0178] It is recommended that the filament layer consolidation time be in the range of 200 to 20000 ms, preferably in the range of 200 to 15000 ms and most preferably in the range of 200 to 10000 ms.

[0179] The density air velocity used in this density unit is set in the range of 0.2 to 4.0 m / s, preferably in the range of 0.4 to 1.8 m / s. It is recommended that the density temperature during thermal density be in the range of 100°C to 250°C, preferably in the range of 120°C to 220°C. In one of the Petition 870220076974, dated 08 / 26 / 2022, p. 89 / 144 79 / 115 modalities, this densification temperature is in the range of 90°C to 140°C, mainly from 110°C to 130°C.

[0180] According to several advantageous embodiments, nonwoven fabric includes a layer of two-component filaments: - a component (A) produced from polyethylene terephthalate (PET) and the second component (B) produced from a polyolefin, particularly polyethylene, while the consolidation temperature is preferably in the range of 90°C to 140°C, especially 100°C to 140°C; - a component (A) produced from polyethylene terephthalate (PET) and the second component (B) produced from a polyolefin, particularly polypropylene, while the consolidation temperature is preferably in the range of 90°C to 160°C, especially 110°C to 160°C; - a component (A) produced from polyethylene terephthalate (PET) and the second component (B) produced from a copolymer of polyethylene terephthalate (CoPET), while the consolidation temperature is preferably in the range of 140°C to 230°C; - a component (A) produced from polylactic acid (PLA) and the second component (B) produced from a polyolefin, particularly polyethylene or polypropylene, while the consolidation temperature is preferably in the range of 80°C to 140°C; Petition 870220076974, dated 08 / 26 / 2022, pp. 90-144 80 / 115 - a component (A) produced from polypropylene (PP) and the second component (B) produced from a polyolefin, particularly polyethylene or a copolymer of polypropylene and polyethylene, wherein the consolidation temperature is preferably in the range of 90°C to 140°C, especially 100°C to 140°C.

[0181] The nonwoven fabric according to the invention contains a combination of layers of various compositions, a suitable pre-densification temperature, activation and bonding derived from penetration of recommended temperature ranges for the individual layers.

[0182] The temperature ranges specified above can be used in several mutually separate stages, so that the consolidation air temperature and, likewise, the consolidation air velocity remain within the specified range, even if the consolidation mechanisms have different levels in the various zones.

[0183] This invention is based on the observation that a nonwoven fabric according to the intended design can be engineered to be relatively bulky and thereby relatively thick, while on the other hand maintaining satisfactory stability. The layer according to the invention exhibits excellent elasticity even after being subjected to the effects of a load, namely a pressure load. These advantageous characteristics can be obtained with relatively low basic weights of nonwoven fabric.

[0184] For the method according to the invention, there is, moreover, a specific advantage in the fact that Petition 870220076974, dated 08 / 26 / 2022, pp. 91 / 144 81 / 115 Continuous production of nonwoven fabric is carried out using a simple method, with relatively high production speeds and no interruptions in the production process. The production parameters of nonwoven fabric are highly variable, flexible, and adaptable during the production process, thanks to which it is possible to produce different end products without interrupting the production process. The stages of the procedure, consisting of pre-consolidation, activation, and consolidation, can also be easily modified in terms of their parameters.

[0185] The method according to the invention can be carried out by means of a simple “in-line” method, while retaining the option of carrying out several stages of the production process “off-line”, if necessary. The pre-consolidation, shrink activation and final consolidation stages can thus be easily separated from the actual production of the laminated material. It can be concluded that it is possible to produce an entirely new fabric with a very advantageous 3D structured surface, with large volume and large thickness, exhibiting satisfactory compression resistance by means of a simple, inexpensive and effective method. Several parameters of the resulting nonwoven fabric or nonwoven layer are variable and flexibly adaptable throughout the production process.

[0186] The nonwoven fabric according to the invention may be, for example, a two-layer fabric, produced on the laboratory production line of the Polymer Systems Center of UTB University in Zlín. This laboratory production line, model number LBS-300, is capable of producing Petition 870220076974, dated 08 / 26 / 2022, pp. 92 / 144 82 / 115 single-component or two-component filaments for spunbond (continuous heat-sealed filament) or meltblown (meltblown) nonwoven fabrics. Its extrusion system, consisting of two extruders, can heat polymers to a temperature of 450°C. Spunbond (continuous heat-sealed) nonwoven filaments can be produced using a 72-hole spunbond extruder (continuous spinning) with a diameter of 0.35 mm and a length of 1.4 mm in a 6x6 cm square area. Several extruder arrangements are possible for processing two-component filaments – core / sheath, side-by-side components, sectors, or islands. The system is open; extraction air pressure is available in the inlet system up to a level of 150 kPa. The filaments can be removed in their original condition or they can be deposited onto a conveyor belt that operates at a speed in the range of 0.7 to 12 m / min.The final product width does not exceed 10 cm. The total extruded quantity can be adjusted in the range of 0.02 to 2.70 kg / h. The final base weight can be adjusted in the range of 30 to 150 g / m2. Additionally, there is the option to consolidate the filament layer using a calender roll at a temperature of up to 250°C.

[0187] To create a consolidation model using an air current under laboratory conditions (examples 1-4), a standard stationary furnace was used. Due to the very different heat transfer conditions inside the furnace with a static atmosphere and in the forced air current mechanism passing through the fabric, and also due to the thermal losses resulting from opening and closing the furnace, it would be necessary Petition 870220076974, dated 08 / 26 / 2022, pp. 93 / 144 83 / 115 set an activation + connection time of 3 minutes at 130°C.

[0188] The aforementioned laboratory production line was used to create the layers described in the examples. In examples 1-6, a compact roller was used behind the wiring bundle at room temperature with minimal downward pressure. In the remaining examples, a hot air stream (130°C) created by means of a hot air gun with an attachment was used instead of the compact roller.

[0189] The nonwoven fabric consists of two layers of two-component core / sheath filaments with a circular cross-section. The mass ratios of the core and sheath and the production line configurations are given in the table. In the production of the individual layers, the following temperature profiles were defined for the defined polymer combinations:

[0190] PET / PE: Component A = PET (polyethylene terephthalate, polymer type 5520, manufacturer Invista) Component B = PE (polyethylene, ASPUN 6834, manufacturer Dow)

[0191] The extruder for component A was heated to a temperature of 340°C (3 zones were heated to 340°C, The extruder for component B was heated to a temperature of 235°C (3 zones were heated to 200°C, 215°C, and 235°C, respectively). The spinning beam temperature was set to 305°C. The amount of polymer processed was set to 0.25 g / min / capillary. The filaments were cooled with air at a temperature of 20°C. Petition 870220076974, dated 08 / 26 / 2022, pp. 94 / 144 84 / 115

[0192] PP / PE: Component A = PP (polypropylene, Tatren HT 2511, manufacturer Slovnaft) Component B = PE (polyethylene, ASPUN 6834, manufacturer Dow)

[0193] The extruder for component A was heated to (3 zones were heated to 195°C, 220°C and 240°C, respectively), the extruder for component B was heated to a temperature of 235°C (3 zones were heated to 200°C, 215°C and 235°C, respectively). The spinning beam temperature was set to 240°C. The amount of polymer processed was set to 0.25 g / min / capillary. The filaments were cooled with air at a temperature of 20°C.

[0194] PLA / PE: Component A = PLA (polylactic acid, Ingeo, manufacturer Nature Works) Component B = PE (polyethylene, ASPUN 6834, manufacturer Dow)

[0195] The extruder for component A was heated to a temperature of 240°C (3 zones were heated to 195°C, (220°C and 240°C, respectively), the extruder for component B was heated to a temperature of 235°C (3 zones were heated to 200°C, 215°C, and 235°C, respectively). The spinning beam temperature was set to 240°C. The amount of polymer processed was set to 0.25 g / min / capillary. The filaments were cooled with air at a temperature of 20°C.

[0196] PLA / coPLA: Component A = PLA (polylactic acid, Ingeo, manufacturer Nature Works) Petition 870220076974, dated 08 / 26 / 2022, pp. 95 / 144 85 / 115 Component B = coPLA (polylactic acid copolymer, Ingeo, manufacturer Nature Works)

[0197] The extruder for component A was heated to a temperature of 240°C (3 zones were heated to 195°C, (220°C and 240°C, respectively), the extruder for component B was heated to a temperature of 235°C (3 zones were heated to 200°C, 215°C, and 235°C, respectively). The spinning beam temperature was set to 240°C. The amount of polymer processed was set to 0.25 g / min / capillary. The filaments were cooled with air at a temperature of 20°C. Example 1 2 3 4 5 6 comparative invention invention invention comparative Preconsolidation Compact roll A1 PET PET PET PET PET PP B1 PE PE PE PE PE PE A1 / B1 70 / 30 70 / 30 70 / 30 70 / 30 70 / 30 60 / 40 filament type in layer TC / SC / SC / SC / SC / SC / S A2 PET PP PP PP PP PP B2 PE PE PE PE PE PE A2 / B2 70 / 30 60 / 40 40 / 60 60 / 40 40 / 60 60 / 40 Filament Type in Layer MC / SC / SC / SC / SC / SC / S Base weight gsm 40 + 40 40 + 30 40 + 30 80 + 60 80 + 60 60 + 60 Petition 870220076974, dated 08 / 26 / 2022, pp. 96 / 144 86 / 115 (Layer T + Layer M) Tensile strength in MD N / cm 2 1 2 2 1 3 Tensile strength at maximum elongation (peak elongation) - MD % 2 115 114 121 111 126 Filament diameter in layer T pm 23 22 23 23 22 x Filament diameter in layer M pm x 23 22 21 20 21 Recovery % 99 97 97 97 98 87 Elasticity % 15 24 24 18 17 19 Compressibility mm 0.114 0.214 0.202 0.257 0.248 0.169 Thickness mm 0.76 0.89 0.84 1.43 1.38 0.89 Volume m3 / kg 105 79 83 98 101 136 Average shrinkage % MD -6% -5% -5% -4% -5% 0% Average shrinkage % CD -4% -4% -4% -2% -3% 0% Average shrinkage % z 13% 25% 28% 28% 26% 2%

[0198] In examples 1-6, for the first filament preconsolidation, a compact roll at room temperature was used directly behind the spinning beam, which significantly affected the structural change caused by the activation of the T-layer - the increase in thickness (in Petition 870220076974, dated 08 / 26 / 2022, pp. 97 / 144 87 / 115 z direction) was significantly limited. Example 6 shows that layer M does not shrink on its own. Example 1 shows the degree of increase in the thickness of the fabric consisting of layer T by 13%. The calculation of the change in fabric volume shows that the increase in thickness corresponds approximately to the reduction in length and width and that the total volume of the fabric did not change. Examples 2-5 show approximately the same shrinkage in the MD and CD directions, a more significant increase in the thickness of the nonwoven fabric, which also corresponds to an increase in total volume (approx. +15% to +20%). Without wanting to be limited by theory, we assume that this increase is caused by the forced shrinkage of layer M. Example 7 8 9 10 11 Comparative Invention Invention Invention Invention Pre-consolidation Hot Air Stream (HAK) A1 PET PET PET PET PET PET B1 PE PE PE PE PE A1 / B1 70 / 30 70 / 30 70 / 30 70 / 30 70 / 30 Filament type in layer TC / SC / SC / SC / SC / S A2 PET PP PP PP PP B2 PE PE PE PE PE A2 / B2 70 / 30 60 / 40 60 / 40 60 / 40 40 / 60 Filament type in layer MC / SC / SC / SC / SC / S Base weight gsm 40 + 40 40 + 30 40 + 30 80 + 60 80 + 60 Petition 870220076974, dated 08 / 26 / 2022, pp. 98 / 144 88 / 115 Example 7 8 9 10 11 Comparative invention invention invention invention Filament diameter in layer T pm 22 23 35 23 22 Filament diameter in layer M pm 22 21 19 22 22 Recovery % 99 98 97 97 99 Elasticity % 35 40 44 38 40 Compressibility mm 0.496 0.608 0.779 0.840 0.864 Thickness mm 1.34 1.52 1.77 2.21 2.16 Volume m3 / kg 60 46 44 63 65 Average shrinkage % MD -5% -6% -5% -6% -4% Average shrinkage % CD -6% -4% -4% -6% -2% Average shrinkage % z 92% 130% 131% 123% 119%

[0199] In examples 7-11, a stream of hot air at a temperature of 130°C was used directly behind the spinning beam for the first pre-consolidation of the filaments. The filaments were not compressed and the structural change during activation occurred significantly in the z direction, and the total volume of the material also increased significantly.

[0200] In examples 2-8 and 8-11, according to the invention, in the first layer T the core is made of polymer A1 (polyethylene terephthalate, polymer type 5520, manufacturer Invista) and in the second layer M the core is Petition 870220076974, dated 08 / 26 / 2022, pp. 99 / 144 89 / 115 consisting of A2 polymer (polyethylene, ASPUN 6834, Manufacturer Dow). The difference in tensile and flexural modulus of elasticity is greater than 500 MPa.

[0201] Examples according to the invention, 4+5 and 10+11 show, in comparison with examples according to the invention, 2+3 and 8+9, a smaller volume, which is mainly caused by the significant difference in the base weight of the nonwoven fabric. The higher total base weight also represents a greater load on the lower layer, which, thanks to its elasticity, is slightly loose and therefore the total volume of the layer is reduced. Example 13 14 15 16 17 invention invention invention invention invention Pre-consolidation Hot Air Stream (HAK) A1 PLA PET PET PET PP1 B1 PE PE PE PE PE A1 / B1 60 / 40 70 / 30 70 / 30 70 / 30 70 / 30 Filament type in layer TC / SC / S and EC / SC / SC / S A2 PP PP PP Crimped staple cellulose fibers and PE powder PP2 B2 PE PE PE PE A2 / B2 50 / 50 50 / 50 50 / 50 70 / 30 Filament type in layer MC / SS / SC / SC / S Base weight gsm 40+30 40+30 40+30 40+120 12.5+12.5 Filament diameter in layer T um 25 23 30 30 27 Petition 870220076974, dated 08 / 26 / 2022, pp. 100 / 144 90 / 115 Example 13 14 15 16 17 invention invention invention invention invention Filament diameter in layer M one 23 23 23 25 17 Recovery % 98 98 95 99 85 Elasticity % 35 30 33 55 57 Compressibility mm 0.466 0.438 0.452 3.960 0.428 Thickness mm 1.33 1.46 1.37 7.20 0.45 Volume m3 / kg 53 48 51 22 56 Average shrinkage % MD -6% -4% -9% -5% 0% Average shrinkage % CD -4% -3% -11% -6% 0% Average shrinkage % z 43% 108% 67% 23% 3%

[0202] In examples 13-17, a stream of hot air at a temperature of 130°C was used directly behind the spinning bundle for the first pre-consolidation of the filaments. In examples 14 and 15, filaments with a cross-section that supports crimping (eC / S, S / S) were used in one of the layers.

[0203] In example 13, according to the invention, in the first layer T the core consists of the first load-bearing polymer A1 (polylactic acid, Ingeo, manufacturer Nature Works) and in the second layer M the second load-bearing core consists of polymer A2 (polyethylene, ASPUN Petition 870220076974, dated 08 / 26 / 2022, pp. 101 / 144 91 / 115 6834, Manufacturer Dow). The difference in tensile and flexural modulus of elasticity is greater than 200 MPa.

[0204] In examples 14-15, according to the invention, in the first layer T the core is made of polymer A1 (polyethylene terephthalate, polymer type 5520, manufacturer Invista) and in the second layer M the core is made of polymer A2 (polyethylene, ASPUN 6834, manufacturer Dow). The difference in tensile and flexural modulus of elasticity is greater than 500 MPa.

[0205] Example 16 describes the combination of the T layer of bonded and spun filaments and the M layer of crimped discontinuous cellulose fibers (by airflow). The ratio of forces required to bend the filament 90° is greater than 2 (A1 polymer filament): 1 (cellulose fiber)

[0206] In example 17, according to the invention, in the first layer T the core consists of the first load-bearing polymer A1 (polypropylene 1 = Mosten NB425 da In the first layer (Unipetrol), the second load-bearing core (M) consists of polymer A2 (polypropylene 2 = MR 2002 from Total Petrochemicals). The difference in flexural modulus of elasticity is 100 MPa.

[0207] Examples 1-5 and 7-16 use shrinkage. Examples 6 and 7 do not contain any shrinking layers.

[0208] The following examples 18-20 represent a nonwoven fabric, produced on a spunmelt production line using REICOFIL 5 technology with two bicomponent spunbond spinnerets. Example 18 Petition 870220076974, dated 08 / 26 / 2022, pp. 102 / 144 92 / 115

[0209] The first layer (T) was produced using two-component sheath / core (C / S) nozzles with a round cross-section. The weight ratio of components A:B in the filament was 70:30. The filament core was made of PET (Invista type 5520 polymer) and the sheath was made of PE (Dow ASPUN 6834). Production conditions were such that the filaments formed irregular arcs or wavy sections in arbitrary orientations. The layer was pre-consolidated using HAK (hot air blade) and HAF (hot air flow). The second layer (M) was produced with two-component sheath / core (C / S) nozzles with a round cross-section and deposited over the first pre-consolidated layer. The weight ratio of the components in the filament was 70:30. The filament core was made of PP (Borealis HG475FB type polymer) and the sheath was made of PE (Dow ASPUN 6834). The filaments themselves in the layer do not exhibit curling.Both layers underwent additional pre-consolidation using HAK (hot air blade) and HAF (hot air flow) and were subsequently fully connected by hot air in the bonding unit. Example 19

[0210] The first layer (T) was produced using two-component eccentric core / sheath (eC / S) type nozzles with a round cross-section (the nozzles used were those disclosed in European patent application EP3771761 by REIFENHAUSER GMBH & CO. KG MASCHI-NENFABRIK). The weight ratio of the components in the filament was 50:50. The filament core was made of PP (Exxon type 3155 polymer) and the sheath was made of PE (ASPUN 6850). Petition 870220076974, dated 08 / 26 / 2022, pp. 103 / 144 (Dow 93 / 115). Production conditions were established in such a way that the filaments would form curls. The first layer was pre-consolidated using HAK (hot air blade) and HAF (hot air flow). The second layer M was produced using two-component eccentric core / sheath (eC / S) nozzles, identical to the first layer, and deposited over the first pre-consolidated layer. The weight ratio of components A:B in the filament was 45:55. The filament core was made of a PP blend (Exxon type 3155 polymer mixed with 4.5% Borealis type HL712FB polymer and 0.6% TiO2 white pigment) and the sheath was made of PE (ASPUN 6834 from Dow). (Dow). The production conditions were set up in such a way that the filaments themselves formed curls. Both layers were subjected to additional pre-consolidation using HAK (hot air blade) and HAF (hot air flow) and were subsequently hot air bonded in the bonding unit. Example 20

[0211] The first layer T was produced using two-component sheath / core (C / S) nozzles with a round cross-section. The weight ratio of components A:B in the filament was 70:30. The filament core was made of PET (Invista type 5520 polymer) and the sheath was made of PE (Dow ASPUN 6834). Production conditions were set so that the filaments formed irregular arcs or wavy sections in arbitrary directions. The layer was pre-consolidated using HAK (hot air blade) and HAF (hot air flow). The second layer M was produced using two-component eccentric core / sheath nozzles. Petition 870220076974, dated 08 / 26 / 2022, pp. 104 / 144 94 / 115 (eC / S) round cross-section (the nozzles used were the nozzle disclosed in European patent application EP3771761 by REIFENHAUSER GMBH & CO. KG MASCHINENFABRIK) and deposited in the first pre-consolidated layer. The weight ratio of components A:B in the filament was 45:55. The filament core was formed from a mixture of PP (Exxon type 3155 polymer mixed with 4.5% of Borealis type HL712FB polymer and 0.6% of a TiO2 white pigment) and the sheath was formed from PE (Dow ASPUN 6834). The production conditions were established in such a way that the filaments themselves in this layer would form curls. Both layers underwent further pre-consolidation using HAK (hot air blade) and HAF (hot air flow) and were subsequently fully bonded by hot air at the bonding unit.

[0212] The process parameters for examples 1820 were defined according to the description above; the exact values ​​are shown in the table below: Example 18 19 20 A1 PET PP PET B1 PE PE1 PE A1 / B1 70 / 30 50 / 50 70 / 30 First Layer Filament Type C / S eC / SC / S A2 PP PP Blend PP B2 PE PE2 PE A2 / B2 70 / 30 45 / 55 45 / 55 Second Layer Filament Type C / S eC / S eC / S Basis weight (g / m2) 30+30 30+30 35 + 25 Melting point A1 Above 200°C Above 150°C Above 200°C Petition 870220076974, dated 08 / 26 / 2022, pp. 105 / 144 95 / 115 Melting point B1 130°C 131°C 130°C Melting point A2 161°C Above 140°C 161°C Melting point B2 130°C 130°C 130°C Difference in flexural modulus A1-A2 Above 500 MPa Above 200 MPa Above 500 MPa Difference in Young's modulus A1-A2 Above 500 MPa Above 200 MPa Above 500 MPa Thickness (mm) 0.9 1.0 1.2 Volume (m3 / kg) 66.7 54.6 50.0 MD Strength (N / 5cm) 78.1 55.5 77.3 Elongation at Peak MD (%) 59 67 60 Elasticity (%) 19 22 33 Compressibility (mm) 0.17 0.22 0.37 Recovery (%) 98 86 99 Average shrinkage Less than 10% of width Less than 10% of width Less than 10% of width First layer filaments (T) (micron) 24 21 25 Second layer filaments (M) (micron) 23 18 22 Abrasion resistance on the first layer side (T) 1 4 1 Abrasion resistance on the second layer side (M) 4 4 4

[0213] Examples 18-20 show, for example, possibilities for various combinations of layer weights. In Petition 870220076974, dated 08 / 26 / 2022, pp. 106 / 144 96 / 115 Example 18: The output of the individual spinnerets was set so that symmetrical products (30+30 gsm) were achieved. In contrast, in Example 20, both spinnerets were adjusted for optimal output, and the spinneret producing filaments with a higher average density also produced a higher filament weight per unit area (35+25 gsm). In Example 19, the filament densities were identical, and the filament weights per unit area were also symmetrical.

[0214] Examples 18-90 also show other possible benefits of the invention. If, as in these examples, layers M and T are used as outer layers of the composite, the final product can offer us the advantages of their different properties, for example, in terms of its own “double face”. For example, an outer layer of Examples 18 and 20 is formed by a layer T with high abrasion resistance (grade 1) and the second layer exhibits almost no resistance (grade 4). In Example 19, the difference in properties is not manifested in abrasion resistance, but for example, in subjectively perceived softness, where the product is classified as softer on the side of layer M. Testing Methods

[0215] The “basic weight” of a nonwoven fabric is measured using the test methodology according to standard EN ISO 9073-1:1989 (corresponding to methodology WSP 130.1). For the measurement, 10 layers of nonwoven fabric are used, while the sample size is 10x10 cm2.

[0216] The “thickness” or “measured height” of a nonwoven material is determined by means of a test measurement methodology in accordance with the European standard EN ISO Petition 870220076974, dated 08 / 26 / 2022, pp. 107 / 144 97 / 115 9073-2:1995 (corresponds to the WSP 120.6 methodology), which is modified as follows: 1. The material must be measured using a sample taken from production that has not been subjected to higher deformation forces or pressure for more than one day (e.g., pressure exerted by the roller in production equipment); otherwise, the material must be left lying freely on a surface for at least 24 hours. 2. The total weight of the upper arm of the measuring machine, including additional ballast, is 130 g.

[0217] The term regeneration or volume recovery here refers to the relationship between the tissue thickness after the release of the acting load and the initial thickness of this tissue. The thickness of a tissue is measured according to EN ISO 9073-2:1995 using a preliminary load force equivalent to a pressure of 0.5 kPa. The procedure for measuring regeneration consists of the following steps: 1. Preparation of tissue samples measuring 10 x 10 cm; 2. Measuring the thickness of 1 piece of fabric; 3. Measuring the thickness of 5 pieces of fabric placed one on top of the other using a preliminary load force equivalent to a pressure of 0.5 kPa (Ts); 4. Applying a load to 5 pieces of fabric placed one on top of the other (at a pressure of 2.5 kPa) in a thickness measuring device for 5 minutes; 5. Release the device and wait for 5 minutes; Petition 870220076974, dated 08 / 26 / 2022, pages 108 / 144 98 / 115 6. Measuring the thickness of 5 pieces of fabric placed one on top of the other using a preliminary load force equivalent to a pressure of 0.5 kPa (Tr); 7. Calculation of regeneration according to the following equation: Regeneration = Tr / Ts (unitless) Ts = thickness of the fresh sample Tr = thickness of the regenerated sample

[0218] The term compressibility here refers to the distance in millimeters by which a nonwoven fabric is compressed by the effect of a defined load during the elasticity measurement. It can also be calculated as the product of elasticity (unitless) * thickness (mm). The elasticity of a nonwoven fabric is measured using the test methodology according to EN ISO 964-1, which is modified as follows: 1. The thickness of a fabric layer is measured; 2. Several samples of the fabric are prepared so that their total thickness after being stacked on top of each other is at least 4 mm, more preferably 5 mm. The group of fabric pieces stacked on top of each other contains at least 1 fabric piece; 3. The thickness of these stacked tissue samples is measured; 4. A force of magnitude 5 N acts on this group of stacked tissue samples at a loading rate of 5 mm / min; Petition 870220076974, dated 08 / 26 / 2022, pp. 109 / 144 99 / 115 5. The distance corresponding to the movement of the fastening elements is measured; 6. Elasticity is calculated according to this equation: R (unitless) = T1(mm) / T0(mm) or R (%) = T1(mm) / T0(mm) * 100% T1 = distance corresponding to the movement of the fastening elements under a load of 5 N [mm] = degree of compression of the stacked textile parts T0 = ​​thickness (according to EN ISO 9073-2:1995 applying a preliminary load force of 1.06 N) [mm]

[0219] The “Ratio of continuous filament length to fabric length” can be measured using three different methods: a) The length of the filaments is measured by stretching the filaments so that they are spread out in a linear section, without curling; b) In a consolidated tissue, to reach a specific level, it is not possible to use method a) for measuring filament length and, therefore, it is necessary to use the following estimate: a. Take an image of the layer being evaluated at a magnification that allows sufficient visibility of the filaments; Petition 870220076974, dated 08 / 26 / 2022, pp. 110 / 144 100 / 115 b. A single filament is selected and its path is traced across the entire image or at least a portion of it; c. Based on the measured length of the filament shown in the image, the actual length of this filament is analyzed; d. The length of the fabric in which the described filament is designated is measured; e. The ratio (percentage) between the estimated filament length and the measured fabric length is calculated; c) In the fabric, using the “method for determining statistical geometric values ​​of filaments in a nonwoven material”, where: a. A geometric representation of the tissue, which was selected for analysis, measures 8 mm in the MD direction and 8 mm in the CD direction, maintaining the total thickness of the sample in the Z direction; b. From a measurement standpoint, the only relevant filaments in the tissue are those that enter the cut sample from one side and exit from the opposite side; c. It is necessary to measure at least 20 filaments. d. The ratio (percentage) between the filament length and the measured length of the fabric is calculated.

[0220] The “free filament section length”, that is, the length of the free filament section between the connection points or connection reliefs, can only be Petition 870220076974, dated 08 / 26 / 2022, pp. 111 / 144 101 / 115 determined essentially through two different methods: 1) Estimation using a two-dimensional image of the tissue: a. Take an image of the layer being evaluated at a magnification that allows sufficient visibility of the filaments; b. Mark the sections of free filaments; c. Measure the lengths of the marked filament sections; d. The measurement is performed on at least 100 randomly selected filament sections, following basic random selection rules, and a statistical calculation is made to determine the average length of a free filament section. 2) In the fabric, using the "method for determining statistical geometric values ​​of filaments in a nonwoven material", where: a. A geometric representation of the tissue, which was selected for analysis, measures at least 8 mm in the MD direction and 8 mm in the CD direction, maintaining the total thickness of the sample in the Z direction; b. In terms of measurement, the only filaments that are relevant are those in such a cross-sectional sample that lead from one connection point to another, or from one connection relief to another. Petition 870220076974, dated 08 / 26 / 2022, pp. 112 / 144 102 / 115 or alternatively from one connecting relief to another connecting point; c. The measurement is performed on at least 100 randomly selected filament sections, following basic random selection rules, and a statistical calculation is made to determine the average length of a free filament section. Martindale Medium Grade Abrasion Resistance Test or Martindale

[0221] Figure 38 is a perspective view of the equipment for the Martindale Medium Grade Abrasion Resistance Test. Figure 39 is a rating scale for evaluating lint formation in the Martindale Medium Grade Abrasion Resistance Test described herein in the published patent application US20200170853A1 of Procter and Gamble.

[0222] The average Martindale abrasion resistance rating of a nonwoven fabric is measured using a Martindale abrasion tester. The test is performed dry. • The nonwoven samples are conditioned for 24 hours at 23±2°C and 50±2% relative humidity; • From each nonwoven sample, cut 10 circular samples with a diameter of 162 mm (6.375 inches). Cut a piece of standard felt into a circle with a diameter of 140 mm; • Secure each sample in each position on the Martindale abrasion test table by first placing the felt. Petition 870220076974, dated 08 / 26 / 2022, pages 113 / 144 103 / 115 cut and then the non-woven sample cut. Next, attach the retaining ring so that there are no visible wrinkles in the non-woven sample. Mount the abrasive holder. The abrasive is a 38 mm diameter, 1 / 32 inch thick FDA-compliant silicone rubber (obtained from McMaster Carr, Item 86045K21-50A). Place the necessary weight on the abrasive holder to apply a pressure of 9 kPa to the sample. Position the assembled abrasive holder on Model #864 so that the abrasive contacts the sample NW as indicated in the Operator's Guide. Operate the Martindale abrasion machine under the following conditions: Mode: Abrasion Test - Speed: 47.5 cycles per minute; and Cycles: 16 cycles After the test stops, place the worn nonwoven fabric on a smooth, matte, black surface and rate its lint formation level using the scale provided in Figure 14. Each sample is evaluated by observing both from the top, to determine the size and number of defects, and from the side, to determine the loft height of the defects. A number from 1 to 5 is assigned based on the best match with the rating scale. The Martindale Average Abrasion Resistance Grade is then calculated as the average rating of all samples and reported to the nearest tenth. Petition 870220076974, dated 08 / 26 / 2022, pages 114 / 144 104 / 115

[0223] For the procedure conditions, the “filament cross-section type” is known, which is defined by the shape of the extrusion tool used to form these filaments. If the procedure conditions are not known, the following estimate can be used: a tissue sample is collected and cross-sectional images of the filament are taken of at least 20 filaments. These cross-sectional images are taken on a free part of the filament, not at the location of a bond or where it is in contact with another filament, as deformation can be expected at these locations. The surface of the components is marked for each cross-section in the image, i.e., independently for each component.The position of the center of gravity of each component is determined based on the determination of the geometric center of a planar object, recorded by the Cartesian coordinate system, in which this geometric center of the filament's cross-section is assigned the coordinates [0; 0]. According to the following equation, the deflection (D) at the location of the center of gravity of each component and in each cross-section of the filament is: D = absolute value of the product (x * y), where x and y are the coordinates of the center of gravity. If one of the x, y values ​​is equal to 0 and simultaneously not equal to the other of these values, the sample will be eliminated from the evaluation.

[0224] The average value and standard deviation are calculated for each component. Petition 870220076974, dated 08 / 26 / 2022, pages 115 / 144 105 / 115

[0225] The filament is considered non-moldable by crimping when the ratio between the sum ((average deflection) plus (standard deviation)) and the total cross-sectional area is less than 5%.

[0226] The filament is assumed to be non-moldable by crimping when the ratio between the differences ((mean deflection) minus (standard deviation)) and the total cross-sectional area is less than 5%.

[0227] The value of the “average filament diameter” in the layer is expressed in SI units, which are micrometers (μη) or nanometers (nm). To determine this average value, it is necessary to take a sample of a nonwoven fabric from at least three locations that are at least 5 cm apart from each other. In each of these samples, it is necessary to measure the diameter of at least 50 individual filaments in each of the investigated layers. For this, it is possible to use, for example, an optical or electron microscope (depending on the diameter of the filaments measured). If the diameter of the filaments in one sample differs significantly from the diameters of the filaments in the other two samples, it is necessary to discard this sample and prepare a new one.

[0228] In the case of circular filaments, their diameter is measured as the diameter of their cross-section. In the case of any other cross-sectional shape of the filaments (for example, in the case of filaments with a hollow or three-ended cross-section), it is necessary to determine the size of the cross-sectional area of ​​each filament measured and recalculate it into a circular area of ​​the same size. Petition 870220076974, dated 08 / 26 / 2022, pp. 116 / 144 106 / 115 The diameter of this theoretical circular area is therefore the diameter of the filament.

[0229] The measured values ​​for each layer composed of all three samples are then combined into a single set of values, from which the average value is subsequently determined. It applies that at least 50% of the filaments have a diameter less than or equal to the median value and at least 50% of the filaments have a diameter greater than or equal to the median value. To determine the median value for a given set of sample values, simply order these values ​​according to size and then select the value located in the middle of this list. If the sample set has an even number of items, the median value is usually determined as the arithmetic mean of the values ​​located at the N / 2 and N / 2+1 locations.

[0230] The term porosity here refers to the volume of pores in the material, which is related to the total volume absorbed by this material.

[0231] The total volume absorbed by the material is in this case equal to the total volume of the nonwoven fabric and for 1 m2 of nonwoven fabric it can be calculated from the value of the thickness (height) of this nonwoven fabric using the following equation: Total volume (m3 / m2) = ((fabric height (mm) / 1000) * 1 (m) * 1 (m)) / m2 of nonwoven fabric

[0232] The volume value to express the porosity of the material can then be calculated using the following equation: Petition 870220076974, dated 08 / 26 / 2022, pp. 117 / 144 107 / 115 Porosity = total tissue volume (m3 / m2) - volumetric weight (m3 / m2)

[0233] The volumetric weight value per 1 m2 of nonwoven fabric can then be calculated using the following equation: volumetric weight (m3 / m2) = (base weight (g / m2) / 1000) / polymer weight density (kg / m3)

[0234] The weight density value of the polymer can be calculated from the known composition or by measurement in accordance with ISO 1183-3:1999, for the filament it is equal to the weighted average density specified above.

[0235] The porosity value of the material can then be calculated using the following equation: Porosity (%) = 1 — tissue height (mm) x weight density:v:nmej * 100%

[0236] Alternatively, porosity can be expressed as the free area in m3 per weight of a nonwoven fabric in kg. This value can be calculated according to the following formula: Porosity (-—| = \k9j base weight (^2) x textile height (mm) weight density (&) Petition 870220076974, dated 08 / 26 / 2022, pp. 118 / 144 108 / 115

[0237] In the case of layered material where there is a large difference between the individual layers, the total porosity for the entire material can be expressed or the thickness and basic weight of the individual layers can be defined and the porosity can then be calculated for the given layers.

[0238] The volume of a nonwoven fabric represents a simplified expression of porosity that is suitable only for mutual comparison of nonwoven fabrics of similar composition or for an approximate comparison. One versed in the field will understand that the calculation formula does not include the polymer density and is able to assess the suitability and limitations of this calculation. Volume (kg / m3) = base weight (g / m2) / fabric height (mm)

[0239] The stiffness of a nonwoven fabric, expressed by the Handle-O-Meter (HOM) measurement, is determined in accordance with the international standard WSP 90.3. The sample size, unless otherwise indicated for the measured value, is 100 x 100 mm. HOM is measured in the MD direction and the CD direction separately. Unless the MD or CD direction is specified, the arithmetic mean of these two values ​​is taken. Method for determining statistical geometric values ​​of filaments in a nonwoven material.

[0240] The following part of the description refers to the software methods used for the analysis of nonwoven fabric material samples with the aim of characterizing Petition 870220076974, dated 08 / 26 / 2022, pp. 119 / 144 109 / 115 its geometric characteristics. This method uses machine learning to identify the individual filaments contained in the sample, followed by a geometric analysis of these filaments to obtain statistical data suitable for characterizing the material. The results include the separation of the orientation and density of the filaments. The working procedure used to perform this analysis was developed by Math2Market GmbH and is part of the GeoDict digital materials laboratory software. Step 1: Capturing a three-dimensional gCT image of the sample

[0241] First, a 3D image of the nonwoven tissue sample is created by scanning this sample using a pCT scanner. The 3D image consists of a uniform Cartesian grid in which, for each of its cells (volumetric element or voxel), an X-ray radiation attenuation value is determined at the corresponding location of the sample studied. The area formed by pores, as a rule, presents a lower degree of this attenuation (lower grayscale value), while the material phase presents higher values, the size of which depends on the specific material and the arrangement of the pCT equipment used. Step 2: Segmentation of gCT images for the purpose of separating material from the pore-containing space.

[0242] For further analysis purposes, the grayscale image that was created is then subjected to filtering, which is carried out with the aim of eliminating noise by means of a non-local instrument method [1]. Petition 870220076974, dated 08 / 26 / 2022, pages 120 / 144 110 / 115 Subsequently, the image is converted to binary form using the global threshold value derived using Otsu's algorithm [2]. Through this conversion to binary form, each voxel of the image is classified to contain either pore-created space or filament material. Voxels with grayscale values ​​below the threshold value are classified as pore-created space. All other voxels are classified as filament material. For both procedures, through which interferences are filtered and compared to a threshold value, the ImportGeo module of the GeoDict software is used. Step 3: Density separation analysis of the material

[0243] In addition, the material density separation is calculated for the Z direction. For each cross-section of the image (created at the given depth in the Z direction) the material density is calculated as the number of voxels of white material divided by the total number of voxels in the respective cross-section. This analysis is performed using the MatDict function in the GeoDict program. Step 4: Using neural networks to identify central curves of filaments.

[0244] The main demanding task associated with distinguishing individual filaments in gCT images lies in the fact that for binary conversion the filaments are not separated from each other in space at the points of contact. This can result in insufficient segmentation, where multiple objects (filaments) are erroneously classified as a single filament. Petition 870220076974, dated 08 / 26 / 2022, pages 121 / 144 111 / 115

[0245] For filament separation, Math2Market GmbH has created a procedure that allows the identification of the filament's central curves. These central curves are displayed in a binary voxel image with the same size as the original image. In this image, voxels located at a distance of approximately 1-2 voxels from the center of the filament are marked.

[0246] For this purpose, the semantic segmentation method using neural networks was used [3]. The image is analyzed using a sliding 3D input window, which moves above this image. For each input window, a smaller output window is defined, which is centered on the input window. The neutral network analyzes the binary voxel values ​​in the input window and creates a prediction for each voxel in the output window. The predicted value determines whether the voxel within the output window is part of the central curve. By combining the results obtained for all these output windows, a binary image is obtained, which classifies each voxel of the material in the original image. This image transformation is performed using the FiberFind-AI module in the GeoDict program using the Ten-sorflow software library [4]. Step 5: Creating data to train the neural network

[0247] For the purposes of so-called neural network training, which is used to perform the aforementioned transformation, the company Math2Market GmbH obtained several artificial 3D images of nonwoven materials using the FiberGeo stochastic module to generate structures, which form part of the GeoDict software program. This module generates analytical geometric visual images of filaments as rows. Petition 870220076974, dated 08 / 26 / 2022, pages 122 / 144 112 / 115 of segments. Simultaneously, it provides an output in the form of a binary image of the filament structure, which is comparable to the results of the binary conversion performed in step 2.

[0248] By modifying the dimensions of the filaments in the analytical image by approximately 2-3 voxels, it is possible to create an image of the central curves corresponding to the artificial fibrous structure.

[0249] This pair of images (i.e., filament images and central curve images) can be used later to train neural networks for the purpose of converting a filament image into a central curve image. Through this procedure, the tissues effectively “learn to shrink” the filaments in the direction of their central curves. Step 6: Tracing the central curves of filaments in order to generate a geometric representation of these filaments.

[0250] After reducing the filaments so that these filaments are represented only by their central curves, it is assumed that the central curves are not in mutual contact. In the subsequent separation of the individual central curves by the analysis of connected components in the central curve image, it is assumed that each component corresponds to the central curve of a filament. A connected component is concurrently defined as a partial set of voxels of the material, all of which have the same color and cannot be enlarged by adding any other voxels of the same color that are touching each other. Petition 870220076974, dated 08 / 26 / 2022, pp. 123 / 144 113 / 115

[0251] For each central curve, this set in the range of voxel sets is then traced to generate the geometric representation of the corresponding filament in the form of a sequence of mutually connected segments (broken line). This step is also part of the FiberFind-AI function in the GeoDict program. Step 7: Histogram calculation for filament orientation separation

[0252] To find the orientation arrangement in any plane (for example, in the XY plane), first each filament segment is projected onto this plane, and then the angle within this plane is calculated. Then the orientation angle histogram of all segments is calculated. Finally, this orientation angle histogram is visualized being plotted in polar coordinates, while the radius at the given angle is proportional in count to the occurrence of the corresponding orientation. This analysis is repeated for the two remaining planes (XZ and YZ). [1] Buades, Antoni, Bartomeu Coll a J-M. Morel, „A non-local algorithm for image denoising.” Computer Vision and Pattern Recogni-tion, 2005, CVPR 2005. IEEE Computer Society Conference on computer vision, sv. 2, IEEE, 2005. [2] Otsu, Nobuyuki, „A threshold selection method from graylevel histograms.” IEEE transactions on systems, man, and cybernetics 9.1 (1979): 62-66. [3] Noh, Hyeonwoo, Seunghoon Hong a Bohyung Han, „Learning deconvolution network for semantic segmentation.” Proceedings of the IEEE international conference on computer vision. 2015. Petição 870220076974, de 26 / 08 / 2022, pág. 124 / 144 114 / 115 [4] Martín Abadi, Ashish Agarwal, Paul Barham, Eugene Brevdo, Zhifeng Chen, Craig Citro, Greg S. Corrado, Andy Davis, Jeffrey Dean, Matthieu Devin, Sanjay Ghemawat, Ian Goodfellow, Andrew Harp, Geoffrey Irving, Michael Isard, Rafal Jozefowicz, Yangqing Jia, Lukasz Kaiser, Manjunath Kudlur, Josh Levenberg, Dan Mané, Mike Schuster, Rajat Monga, Sherry Moore, Derek Murray, Chris Olah, Jonathon Shlens, Benoit Steiner, Ilya Sutskever, Kunal Talwar, Paul Tucker, Vin-cent Vanhoucke, Vijay Vasudevan, Fernanda Viégas, Oriol Vinyals, Pete Warden, Martin Wattenberg, Martin Wicke, Yuan Yu and Xiaoqiang Zheng, “TensorFlow: Large-scale machine learning on heterogeneous systems”, 2015. Software is accessible at the website: tensorflow.org. UTILIDADE INDUSTRIAL

[0253] The invention can be used whenever a bulky soft non-woven fabric with greater compressibility and improved ability to recover to its initial state is required – for example, in the industrial production of hygiene products, where this material, according to the invention, can be used to manufacture various parts of hygiene products with absorbent characteristics (e.g., baby diapers, products for people suffering from incontinence, personal hygiene products, changing mats, etc.), or health products, for example, as part of protective clothing, surgical face masks, bed sheets and other products containing waterproof materials. Other application possibilities include various industrial areas, for example, use as part of protective clothing, use as part of filtration, insulation, packaging and noise reduction products, use in Petition 870220076974, dated 08 / 26 / 2022, pages 125 / 144 115 / 115 footwear, automotive or furniture industries etc. The invention is particularly advantageous in areas where increasing demands are placed on the volume, compressibility and recovery of the fabric in combination with the need for continuous filament inclusion.

[0254] For various applications of nonwoven fabrics, it is desirable to use various filament thicknesses. For example, when used as a top sheet or back sheet in an absorbent hygiene product, thinner filaments are more advantageous (e.g., in the diameter range of 10-40 microns). For example, when used as an inner layer of an absorbent hygiene product, slightly larger filament thicknesses are more advantageous (e.g., in the diameter range of 15 to 50 microns). For example, when used in filtration products as an auxiliary or capture layer. For auxiliary layers, a larger filament thickness is generally required (approx. 30-100 microns), whereas for capturing parts, thinner filaments (10-40 microns) are generally appropriate. A person skilled in the art will easily determine the appropriate filament thickness for their own application. Petition 870220076974, dated 08 / 26 / 2022, pages 126 / 144

Claims

1 / 7 CLAIMS 1. LAYERED NON-WOVEN FABRIC, characterized by containing: - a first layer (T) of filaments, containing continuous filaments containing a first carrier polymer (A1) and a first linker polymer (B1), which forms at least part of the surface of said continuous filaments and having a melting temperature at least 5°C lower than that of the first carrier polymer (A1), wherein the first layer (T) of filaments contains mutually spaced linking points, which interconnect the filaments and are formed by the first linker polymer (B1), - a second layer (M) of filaments, containing filaments containing a carrier material, whose stiffness is lower than the stiffness of the first carrier polymer (A1), and a second linker polymer (B2), which has a melting temperature at least 5°C lower than that of the carrier material and the first carrier polymer (A1),wherein the second layer (M) of filaments contains mutually spaced bonding points, which interconnect the filaments of the second layer (M) and are formed by the second bonding polymer (B2), wherein essentially each filament intersection forms a bonding point and the nonwoven fabric has no bonding impressions.

2. NON-WOVEN FABRIC, according to claim 1, characterized in that the median spacing distance between mutually adjacent bonding points in the first layer (T) of filaments is less than or equal to 8 mm and / or a median spacing distance between mutually adjacent bonding points in the second layer (M) is less than or equal to 8 mm.

3. NON-WOVEN FABRIC, according to claim 1 or 2, characterized in that the carrier material of the filaments in the second layer (M) of filaments is a second carrier polymer (A2), whose tensile strength and / or flexural strength is at least 100 MPa less than the tensile strength and / or flexural strength of the first carrier polymer (A1), wherein the second linking polymer (B2) forms at least part of the surface of said filaments and said filaments of the second layer (M) are continuous filaments.

4. NON-WOVEN FABRIC, according to any of the preceding claims, characterized in that the melting temperatures of the first linking polymer (B1) and the second linking polymer (B2) differ by 0 to 5°C, or the first linking polymer (B1) being the same as the second linking polymer (B2).

5. NON-WOVEN FABRIC, according to any one of claims 3 to 4, characterized in that the first carrier polymer (A1) and / or the second carrier polymer (A2) are selected from a group comprising polyolefins, polyesters, polyamides and their copolymers.

6. NON-WOVEN FABRIC, according to any of the preceding claims, characterized in that the first linking polymer (B1) and / or the second linking polymer (B2) are selected from a group comprising polyolefins, polyesters, polyamides and their copolymers.

7. NON-WOVEN FABRIC, according to any one of claims 3 to 6, characterized in that the first carrier polymer (A1) forms at least 55% by weight of the filaments in the first layer (T) and / or the second carrier polymer (A2) forms less than 55% by weight of the filaments in the second layer (M).

8. NON-WOVEN FABRIC, according to any one of claims 3 to 7, characterized in that the ratio between the weighted average density of the polymers in the continuous filaments of the first layer (T) and the weighted average density of the polymers in the continuous filaments of the second layer (M) is 1.0 to 1.5 and / or a basic weight ratio of the first layer (T) to the basic weight of the second layer (M) is 1.0 to 1.

5.

9. NON-WOVEN FABRIC according to any of the preceding claims, characterized in that the filaments of the first layer (T) of filaments and / or the filaments of the second layer (M) of filaments are of the sheath / core type.

10. NON-WOVEN FABRIC, according to any of the preceding claims, characterized in that the median thickness of the filaments of the first layer (T) of filaments is in the range of 0.8 to 1.5 times the median thickness of the filaments of the second layer (M) of filaments.

11. NON-WOVEN FABRIC, according to any of the preceding claims, characterized in that the thickness of the filaments of the second layer (M) of filaments is less than 30 microns. Petition 870250028283, dated 08 / 04 / 2025, page 22 / 26 4 / 7 12. NON-WOVEN FABRIC, according to any of the preceding claims, characterized in that the first linking polymer (B1) and / or the second linking polymer contain at least 80% by weight of polyethylene.

13. METHOD FOR PRODUCING A LAYERED NON-WOVEN FABRIC, characterized by including the following steps: a) melting a first carrier polymer (A1) and a first binder polymer (B1), which has a melting temperature at least 5°C lower than that of the first carrier polymer (A1), and then feeding them into spinnerets of a first spinning beam, thus forming continuous filaments that have at least a part of their surface formed by the first binder polymer (B1), then cooling and extracting such formed filaments and subsequently depositing them on a conveyor belt, thus forming a first layer (T) of filaments;b) deposit a second layer (M) of filaments over the first layer of filaments, the filaments of the second layer (M) containing a carrier material, wherein its stiffness is less than the stiffness of the first carrier polymer (A1) and a second linking polymer (B2) having a melting temperature at least 5°C lower than the melting temperature of the carrier material and the first carrier polymer (A1); Petition 870250028283, dated 08 / 04 / 2025, page 23 / 26 5 / 7 c) then consolidate - by the effect of heated air from 100°C to 250°C - the first layer (T) of filaments by creating bonding points formed between the filaments of the first linking polymer (B1), and consolidate the second layer (M) of filaments by creating bonding points formed from the second linking polymer (B2), wherein essentially each intersection of filaments forms a bonding point.

14. METHOD, according to claim 13, characterized in that in step b) the second linking polymer (B2) and the carrier material are melted, the carrier material being a second carrier polymer (A2), having a flexural and tensile stiffness that is at least 100 MPa lower than the stiffness of the first carrier polymer (A1), wherein the second carrier polymer (A2) and the second linking polymer (B2) are fed into spinnerets of a second spinning beam, whereby continuous filaments are formed which have at least a part of their surface formed by the second linking polymer (B2), after which such formed filaments are cooled and removed and subsequently deposited on the first layer (T) of filaments on the conveyor belt.

15. METHOD, according to claim 13 or 14, characterized in that in step c) the heated air acts on the (T, M) layers for a period of 200 to 20,000 ms.

16. METHOD according to any one of claims 13 to 15, characterized in that in Petition 870250028283, dated 08 / 04 / 2025, p. 24 / 26 6 / 7 step c) the heated air is conducted through the layers (T, M).

17. METHOD, according to claim 16, characterized in that in step c) the heated air is conducted through the layers (T, M) at a speed of 0.2 to 4.0 m / s.

18. METHOD, according to any one of claims 13 to 17, characterized by further including a layer pre-consolidation step (T, M) carried out after step b), before step c), wherein the layer pre-consolidation is carried out by heating the layers (T, M) to a temperature in the range of 80 to 180°C to partially soften the bonding polymers (B1, B2).

19. METHOD, according to claim 18, characterized in that in the pre-consolidation step performed after step b), heated air is applied to layers (T, M) for 1 to 10,000 ms, wherein the duration of the hot air application in the pre-consolidation step is less than 0.5 times the hot air application time in step c).

20. METHOD, according to claim 18 or 19, characterized in that in the pre-consolidation step, heated air is applied to the (T, M) layers, which flows through the (T, M) layers at a speed of 0.1 to 10 m / s.

21. METHOD, according to any one of claims 13 to 20, characterized by further comprising a pre-consolidation step of layer (T), carried out after step a), before step b), wherein the pre-consolidation is carried out by heating layer (T) to a temperature in the range of 80 to 180°C to partially soften the first linking polymer (B1).

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