Composite absorbent tape

Abstract

The invention provides a composite tape (1) comprising: at least a first layer (3) comprising a plurality of consecutive first polymer filaments (32) and defining a deployment axis (32a) and a plurality of mutually identical contours (33) arranged at least partially consecutively along the deployment axis (32a); a second layer (4) of continuous second polymer filaments (40) forming a surface layer of the tape (1) and placed in contact with the first layer (3); wherein the contour (33) is determined on a cross-sectional plane (32b) perpendicular to the deployment axis (32a), the contour (33) defining a first extension area on the cross-sectional plane (32b) and being inscribed in a circle, the circle being determined on the cross-sectional plane (32b) and defining a second extension area on the cross-sectional plane (32b); and wherein the first extended area is less than 90% of the second extended area.

Description

Technical Field

[0001] The purpose of this invention is to provide a composite absorbent tape.

[0002] In particular, the present invention relates to a tape and a method for forming such a tape, wherein particles mixed with continuous microfilaments are positioned within pores of a high-thickness tape, which can be used for filtration, or, particularly if the particles are liquid-absorbent, for sanitary absorbent articles. Background Technology

[0003] As is known, tapes containing particulate materials are widely used, for example but not limited to, air purification, where particles remove pollutants through adsorption mechanisms. Another broad application involves absorbent structures for absorbent articles, such as those for personal hygiene, like disposable diapers for children, training pants for children, or underwear for adult incontinence, designed to absorb and contain bodily exudates, especially urine.

[0004] These absorbent articles comprise several layers that perform different functions, typically including a top sheet, a bottom sheet, and an absorbent core within other layers. The absorbent core must be able to absorb and retain liquid exudate for extended periods, such as overnight for diapers, and should minimize rewetting to keep the wearer dry and prevent staining clothes or sheets. Modern absorbent cores typically consist of an absorbent structure composed of superabsorbent polymer (SAP) particles (also known as absorbent gelling agents (AGM)) and fibrous materials, which can be natural, such as cellulose fibers, modified natural (e.g., regenerated cellulose-based materials), or synthetic fibers.

[0005] It is well known that absorbent structures can be formed "online" or "in situ" along a transition line to form a complete absorbent article; see, for example, WO2022 / 120693A1, which discloses an absorbent core for use in an absorbent article, comprising a liquid-permeable top cover layer, a bottom cover layer, and a high-fill-factor core layer between the top and bottom cover layers, and first and second superabsorbent polymers, in addition to adhesive-fixed cover layers, at least partially permeated into the high-fill-factor core layer. Furthermore, WO2014 / 001487 discloses particles embedded in porous fabrics and ultrasonically fixed between cover layers.

[0006] However, these methods require each production line (also known as a converter) used to produce the articles to be equipped with a suitable handling system for adding the particles, as well as an unwinding and splicing system for the preformed strip. Furthermore, the formation of the absorbent core can limit overall output.

[0007] As an alternative to online core formation, composite absorbent tapes containing particles (e.g., superabsorbents) can be formed offline in high throughput. These tapes can be fed as so-called rolls to conversion lines for forming articles to be packaged and / or combined with other elements to form absorbent articles, thereby advantageously simplifying conversion equipment and processes and providing production cost advantages due to high throughput.

[0008] WO2021 / 188330A1 discloses an absorbent core for use in absorbent articles, comprising a liquid-permeable top layer, a bottom layer, a thick intermediate layer, and superabsorbent polymer particles at least partially distributed in the intermediate layer.

[0009] WO2020 / 025401 discloses an absorbent core comprising at least a top layer and a bottom layer, each of which consists of 0 to 10 wt% fibrous material (natural or synthetic) and 90 to 100 wt% absorbent polymer particles. The absorbent core is made by dripping a first absorbent polymer or mixture onto one side of a nonwoven material. The composite is then rotated, and a second absorbent polymer is dripped onto the other side of the nonwoven fabric, which is also covered by the underlayer fabric. The absorbent composite is then cut to the desired width and wrapped.

[0010] However, better approaches to the structure are still needed, such as avoiding the use of adhesives to facilitate recycling processes in factories and after-consumer waste, and to reduce the ecological footprint of such products. Furthermore, the application of adhesives involves considerable energy consumption, and the handling of the liquid can be adversely affected by the use of adhesives in absorbent structures.

[0011] Methods to avoid the use of adhesives are also known, such as those described in WO2013 / 152809, in which particles are incorporated into the pores of the preformed strip. For satisfactory particle control, such a loaded strip is wrapped in a coating material, such as a woven or nonwoven strip, in a separate step.

[0012] WO2020 / 103964A1 discloses an open-porous spunbond tape of continuously crimped fibers, wherein at least a portion of the pores can be filled with particles, such as superabsorbents. Even when using crimped fibers, which result in reduced production speed, their thickness leads to poor wrapping, requiring additional tape winding, and relatively low flexibility.

[0013] In contrast, WO2021 / 198894 describes a tape comprising meltblown elastomer fibers, optionally also meltblown non-elastomer filaments, wherein particulate material is trapped within the pores of the tape and at least partially adhered to the fibers due to the latter's adhesiveness during meltblowing. Optionally, this composite may be combined with an auxiliary tape (e.g., a nonwoven fabric) to retain particulate or high-density material for better liquid distribution during use.

[0014] This method involves using discontinuous meltblown fibers formed with an "air knife" technique, where polymer filaments are contacted at the exit of a forming nozzle with attenuating air from an angled direction, thereby cutting the filaments into short pieces with reduced particle control. Furthermore, the need to use elastomeric polymers increases costs and reduces production flexibility and speed, which may be unacceptable.

[0015] Generally speaking, although offline forming of absorbent structures offers advantages over online forming, such as very high throughput using a single production unit, there is still a need to improve the economics and / or properties of the resulting absorbent structures. Furthermore, the use of adhesives in absorbent structures complicates recycling (particularly the recycling of plant waste) and may negatively impact consumer perceptions of unnecessary chemicals. Summary of the Invention

[0016] In this context, the basic technical task of the present invention is to design a composite strip that can substantially eliminate at least some of the aforementioned disadvantages.

[0017] Within the scope of the technical tasks described, a key objective of this invention is to obtain an economically viable composite strip and a related manufacturing method.

[0018] Furthermore, another important objective of this invention is the manufacture of composite strips and related manufacturing methods, which enable high production volumes to be achieved using production units and cheaper raw materials, particularly without the use of adhesives.

[0019] In summary, another object of the present invention is to obtain a composite tape that, in view of the foregoing advantages, is highly effective and does not impair particle control before, during, or after production.

[0020] The technical tasks and specific objectives are achieved through the composite strip of the present invention. Attached Figure Description

[0021] The features and advantages of the present invention will be illustrated below by referring to a detailed description of preferred embodiments of the invention with reference to the accompanying drawings, in which:

[0022] Figure 1A schematic diagram of the layers of a first embodiment of a composite absorbent tape according to the present invention is shown, the composite absorbent tape comprising a matrix and wherein each first polymer filament defines the same profile;

[0023] Figure 2 It shows Figure 1 Exploded view of the composite absorbent tape;

[0024] Figure 3 A schematic diagram of the layers of a second embodiment of a composite absorbent tape according to the present invention is shown. The composite absorbent tape includes a matrix and wherein a first polymer filament defines a distinct and well-defined profile, and wherein a third layer and a fourth layer are also present.

[0025] Figure 4 It shows Figure 3 Exploded view of the composite absorbent tape;

[0026] Figure 5 A tube is shown for a first spinneret of an apparatus for manufacturing a strip according to the invention, wherein the shape of the outer surface is similar to that of the inner surface;

[0027] Figure 6a A cross-sectional view on a cross-sectional plane is shown of the profile of a tube having a first concave shape of a first spinneret for manufacturing a strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0028] Figure 6b A cross-sectional view on a cross-sectional plane is shown of the profile of a tube having a second concave shape of a first spinneret for manufacturing a strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0029] Figure 6c A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having a third concave shape of the tube of the apparatus for manufacturing the strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0030] Figure 6d A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having a fourth convex shape of the tube of the apparatus for manufacturing the strip according to the invention;

[0031] Figure 6e A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having a fifth convex shape of the tube of the apparatus for manufacturing the strip according to the invention;

[0032] Figure 6f A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having a sixth concave shape of the tube of the apparatus for manufacturing the strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0033] Figure 6g A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having a seventh concave shape of the tube of the apparatus for manufacturing the strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0034] Figure 6h A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having an eighth concave shape of the first spinneret of the apparatus for manufacturing the strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0035] Figure 6i A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having a ninth concave shape of the tube of the apparatus for manufacturing the strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0036] Figure 6j A cross-sectional view on a cross-sectional plane is shown of the profile of the tube having a tenth concave shape of the tube of the apparatus for manufacturing the strip according to the invention, wherein the convex portion is highlighted by a shading line;

[0037] Figure 7a A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6a The shape;

[0038] Figure 7b A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6b The shape;

[0039] Figure 7c A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6c The shape;

[0040] Figure 7d A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6d The shape;

[0041] Figure 7e A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6e The shape;

[0042] Figure 7fA perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6f The shape;

[0043] Figure 7g A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6g The shape;

[0044] Figure 7h A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6h The shape;

[0045] Figure 7i A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6i The shape;

[0046] Figure 7j A perspective view of a tube for a first spinneret of an apparatus for manufacturing a strip according to the invention is shown, wherein the outer surface has a cylindrical shape and the profile has Figure 6j The shape;

[0047] Figure 8a A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the profile of the outer surface is similar to the profile of the inner surface, and wherein the tubes have the same profile in the same column and have alternating profiles in the same row.

[0048] Figure 8b A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the profile of the outer surface is similar to the profile of the inner surface, and wherein the tubes have the same profile.

[0049] Figure 8c A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes stacked and alternating in a row, each tube defining a circular profile, and wherein the profile of the outer surface is similar to the profile of the inner surface.

[0050] Figure 8d A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the profile of the outer surface is similar to the profile of the inner surface, and wherein the tubes have the same profile in the same column and alternating concave and convex profiles in the same row.

[0051] Figure 9a A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical and wherein the tubes have the same concave profile.

[0052] Figure 9b A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical and wherein the tubes have the same convex triangular profile.

[0053] Figure 9c A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical and wherein the tubes have the same convex, approximately rectangular profile.

[0054] Figure 9d A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical and wherein the tubes have the same concave, approximately star-shaped profile.

[0055] Figure 10a A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical, and wherein the tubes have the same concave profile, and wherein the tubes alternate with tubes having a circular profile in a checkerboard pattern.

[0056] Figure 10b A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical, and wherein the tubes have two different concave profiles, and wherein the tubes with different profiles alternate in a checkerboard pattern.

[0057] Figure 10c A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical, the tubes have two different profiles, namely concave and convex, and wherein the tubes with different profiles alternate in a checkerboard pattern.

[0058] Figure 10d A cross-sectional view of a first spinneret for manufacturing a strip according to the invention is shown. The first spinneret includes a plurality of tubes, wherein the outer surface is cylindrical, the tubes have two different profiles, namely concave and convex, and wherein the tubes with different profiles alternate in a checkerboard pattern.

[0059] Figure 11A schematic side view of an apparatus for manufacturing a strip according to the invention is shown, the apparatus including an unwinding device for depositing a matrix;

[0060] Figure 12 A schematic diagram of an apparatus for manufacturing a strip according to the invention is shown, wherein the sequence of steps of a first embodiment of a method for manufacturing a strip according to the invention is shown;

[0061] Figure 13 A schematic diagram of an apparatus for manufacturing a strip according to the invention is shown, wherein the sequence of steps of a second embodiment of a method for manufacturing a strip according to the invention is shown;

[0062] Figure 14 A schematic diagram of an apparatus for manufacturing a strip according to the invention is shown, wherein the sequence of steps of a third embodiment of a method for manufacturing a strip according to the invention is shown;

[0063] Figure 15 A schematic side view of a first embodiment of an apparatus for manufacturing a strip according to the invention is shown, wherein there is no unwinding device for depositing the matrix; the apparatus is intended for manufacturing a wiping type strip;

[0064] Figure 16 In another embodiment, it is shown Figure 15 A schematic diagram of the equipment, in which filaments are distributed on an inclined conveyor;

[0065] Figure 17 A schematic side view of a third embodiment of an apparatus for manufacturing strips according to the invention is shown, wherein there is no unwinding device for depositing the matrix; the apparatus is intended for manufacturing wiping type strips;

[0066] Figure 18 A schematic side view of a fourth embodiment of an apparatus for manufacturing a strip according to the invention is shown, wherein there is no unwinding device for depositing the matrix; the apparatus is intended for manufacturing a wiping type strip;

[0067] Figure 19 A schematic side view of a fifth embodiment of an apparatus for manufacturing a strip according to the invention is shown, wherein there is no unwinding device for depositing the matrix; the apparatus is intended for manufacturing a wiping type strip. Detailed Implementation

[0068] In this document, when measured values, values, shapes, and geometric reference values ​​(e.g., perpendicularity and parallelism) are associated with words such as “approximately” or other similar terms such as “almost” or “substantially”, they should be understood to exclude measurement errors or inaccuracies due to production and / or manufacturing variations, and, most importantly, should be understood as deviations from the associated values, measured values, shapes, or geometric reference values ​​that are less than slight deviations. For example, if these terms are associated with values, they preferably indicate deviations of no more than 10% of the value itself.

[0069] Furthermore, when using terms such as “first,” “second,” “upper,” “lower,” “primary,” and “secondary,” they do not necessarily determine order, priority, or relative position, but can simply be used to clearly distinguish their different components.

[0070] Unless otherwise expressly stated, terms such as “processing,” “calculating,” “determining,” and “operating,” as reflected in the following discussion, are considered to refer to the actions and / or processes of a computer or similar electronic computing device that manipulate and / or convert data represented as physical quantities (e.g., electronically recorded quantities in computer equipment and / or memory) into other data similarly represented as physical quantities within computer equipment, recording, or other information storage, transmission, or display devices.

[0071] Unless otherwise stated, the measurements and data reported herein should be regarded as being provided in the International Standard Atmosphere ICAO (ISO 2533:1975).

[0072] Referring to the accompanying drawings, the composite strip according to the present invention is generally referred to as reference numeral 1.

[0073] Generally, the term "fiber" as used herein refers to an elongated fiber with a length-to-diameter ratio of at least about 3:1, typically greater than 10:1, or even greater than 100:1. Synthetic or man-made fibers based on natural materials are typically formed by curing a continuous filament of a molten polymer, which may be a homogeneous or single-component polymer or a mixture of polymers, or may form distinct transverse regions within the filament, with the potential to produce crimped or crimpable fibers. The term "filament" is also used interchangeably for substantially continuous cured fibers, while "fiber" is used to describe discontinuous structures. A typical method for forming tapes from substantially continuous filaments is called "spunbonding," see, for example, US5935512, which produces substantially continuous filaments with diameters between about 1 and 50 μm, typically between 15 and 35 μm.

[0074] "Microfibers" is used to describe fibers obtained by forming meltblown tape, as known, for example, from US8017534, in which a low-viscosity polymer is extruded through a nozzle and stretched by a high-speed airflow blown at an angle to the formed filaments. In this way, the melt disperses, solidifies, and breaks into fibrous tape.

[0075] Recently, CAM (coaxial meltblown) technology has gained particular interest, as it provides substantially continuous microfilaments. The formation of CAM filaments is described in more detail, for example, in US9303334 and represents an important element of this invention, which will be discussed further below.

[0076] Although a wide range of polymers can be selected for these filaments, polyolefins are preferred, and polypropylene is even more preferred. Elastomer polyolefins can be used, but this is not necessary from a performance standpoint, and is preferably not necessary from a commercial standpoint due to their higher cost. If a polymer is used, its content should be less than 5% based on the total weight of the polymer in the filament. The polymer preferably has a melt flow rate (MFR) of 25 g / 10 min or greater than about 25 g / 10 min, preferably greater than about 45 g / 10 min, and typically less than about 2000 g / 10 min, as determined by ASTM D1238 and ISO 1133, and for polypropylene, which is a polymer that can be properly processed with current equipment and methods, it is expressed in grams per 10 minutes at 210°C and a load of 2.16 kg.

[0077] In this context, "ribbon" refers to a matrix of fibers or filaments of a single type or mixture, which may be oriented or randomly oriented and bonded by friction and / or adhesion and / or cohesion, the latter of which can be transferred directly after filament formation, such as during the fiber or filament layup step. Typically, ribbon is self-supporting and allows for handling on production or processing equipment, even if individual sub-ribs of a composite ribbon may not possess sufficient integrity on their own. Ribbon may include particles, such as mixtures of filaments and particles. "Composite ribbon" refers to a combination of (sub)ribbons in a layered configuration, while "continuous ribbon" is substantially infinite in length or in the x-direction corresponding to the machine direction (MD) during production and can be wound into spools or reels, or "segmented" into casks that can be joined together to form a substantially infinite ribbon. Therefore, the continuous strip has a width perpendicular to its length direction, corresponding to the transverse direction during production, which may extend for several meters or less than one meter during the production of the strip, and corresponds to the width used in the processing or forming of the article, as well as a thickness perpendicular to the length and width and significantly less than one of the two.

[0078] Another important element of this invention is the high-volume fabric. The term "high-loft" refers to a fabric with a large volume and low density compared to a flat, papery fabric. High-loft fabrics are characterized by a relatively high porosity. This means that there are relatively large amounts of void space between the fibers, in which particles, such as particles of superabsorbent polymers, can be distributed. A high-loft fiber web (without superabsorbent particles) suitable for use in this invention can have a porosity of less than 0.15 g / cm³ at a pressure of 0.83 kPa (0.12 psi). 3 Especially at 0.01 g / cm 3 Up to 0.15 g / cm 3 Between, or at 0.05 g / cm 3 Up to 0.12 g / cm 3 Between, or at 0.08 g / cm 3 Up to 0.10 g / cm 3 The density is between [specific values]. Preferably, even at pressures greater than 4.14 kPa (0.6 psi), it has a density of less than about 0.20 g / cm³. 3 Especially at 0.01 g / cm 3 Up to 0.20 g / cm 3 Between, or at 0.05 g / cm 3 Up to 0.15 g / cm 3 At densities between these ranges, high-density fiber webs also maintain their openness, where density can be calculated by dividing the basis weight of the high-loft layer by its thickness measured at the corresponding pressure as shown. Suitable high-loft basis weight and thickness can be tailored to the characteristics of a specific application. Specifically, measured at a pressure of 4.14 kPa (0.6 psi), high-loft (sub)fiber webs can have a thickness of at least 0.30 mm, particularly between 0.30 mm and 2.00 mm, or between 0.50 mm and 1.5 mm. The basis weight of high-thickness (sub)fiber webs can be 15 g / m². 2 Up to 500g / m 2 Especially at 30g / m 2 Up to 200g / m 2 For example, at 50g / m 2 Up to 120g / m 2 The diameter of the fibers forming the thick fiber web can vary between these ranges. The fibers forming the thick web can be partially or entirely composed of relatively elastic synthetic fibers, particularly polypropylene (PP), polyamide (PA, such as nylon), or polyethylene terephthalate (PET). The fiber diameter can range, for example, from 0.01 mm to 0.50 mm.

[0079] A specific exemplary embodiment of a high-volume fabric can be an air-bonded carded tape made of short fibers, which are fed into a combing or carding unit that typically separates and aligns the short fibers in the machine direction to form a fiber nonwoven tape generally oriented toward the machine direction. The tape is then drawn through heated rollers, creating bonding (the air-bonding process) across the entire fabric without applying specific pressure.

[0080] Optionally, the high-flow fiber web may include secondary layers with different properties and functions. Such properties may be density, fiber thickness, or fiber composition, and the difference in properties should be greater than about 3%, or about 5%, or even about 10%, based on the corresponding maximum values.

[0081] A third important element of this invention is the particles positioned within the pores of a high-thickness fiber web.

[0082] Such particles can provide a wide range of functions, such as coloring, washing, or adsorbing gaseous or gaseous contaminants for filtration purposes. One particular application involves the absorbency of liquids, whereby the particles are suitable for absorbing liquids, such as water or aqueous solutions, such as bodily exudates, in multiples of their own weight. “Superabsorbent polymer” (SAP) refers to an absorbent material that, as measured by centrifugal retention capacity (CRC) test (EDANA method NWSP 241.0.R2(19)), is capable of absorbing at least 10 times its own weight in a 0.9% saline solution. SAP preferably has a CRC value of at least 15 g / g. SAP is typically a cross-linked polymer that is insoluble in water but can absorb large amounts of fluid. SAP is in granular form so that it is flowable in a dry state. Typical granular SAP is a polyacrylic acid polymer, but other polymer materials can also be used. For example, starch-based granular absorbent polymer materials, polyacrylamide copolymers, ethylene maleic anhydride copolymers, cross-linked carboxymethyl cellulose, polyvinyl alcohol copolymers, cross-linked polyethylene oxide and starch-grafted polyacrylonitrile copolymers can be used.

[0083] SAP can be a polyacrylate and polyacrylic acid polymer crosslinked internally and / or at the surface. The superabsorbent polymer of the present invention can be selected from polyacrylate and polyacrylic acid polymers crosslinked internally and at the surface. The superabsorbent polymer can be internally crosslinked, i.e., polymerization is carried out in the presence of a compound having two or more polymerizable groups, which can be free-radical copolymerized in a polymer network. Preferably, the SAP particles comprise a crosslinked polymer of polyacrylic acid or its salts or polyacrylate or its derivatives.

[0084] The particles, in their dry state, can be relatively small (with a maximum dimension less than 1 mm) and can have an approximately spherical shape, but microparticles, fibers, flakes, spheres, powders, crystalline particles, and other shapes are known to those skilled in the art. Spherical particles can facilitate penetration into the pores of high-density tapes.

[0085] In the composite tape 1 according to the invention, particles are mixed with polymer microfilaments to form a filament-particle mixture. It is readily understood that this mixture can be produced by introducing a flow of particles into the stretching zone of the filament forming apparatus, as will be discussed in more detail below. Thus, the filaments entangle the particles as they move together toward the collecting belt. Once the thick, open-pore tape has been positioned on the collecting belt, the mixture deposits on the high-fiber tape, and at least a portion of the filament and particle mixture permeates into the pores of the high-fiber tape, possibly by means of steps that promote permeation, such as vibration or air suction.

[0086] After explaining the foregoing premises in detail, in one or more preferred but non-exclusive embodiments, the strip 1 may include at least one or more substrates 2.

[0087] If matrix 2 is present, the strip 1 forms an absorbent fabric, which is particularly suitable for manufacturing diapers.

[0088] The matrix 2 is preferably made of high-thickness polymer fibers. Furthermore, the matrix 2 includes pores, as explained more clearly below.

[0089] In each case, the strip 1 includes at least a first layer 3.

[0090] If matrix 2 is present, the first layer 3 is in contact with matrix 2. Furthermore, the first layer 3 comprises mixture 30.

[0091] The mixture 30 at least partially penetrates into the pores. Therefore, the mixture 30 comprises at least a plurality of particles 31 and a plurality of first polymer filaments 32 mixed together.

[0092] Particle 31 is preferably made of cellulose.

[0093] The first polymer filament 32 is preferably continuous. Furthermore, prior to mixing with the particles 31, the first polymer filament 32 defines a spreading axis 32a and a plurality of identical profiles 33 arranged at least partially along the spreading axis 32a. The term "at least partially" means that not all first polymer filaments 32 must define profiles 33 along their spreading axis 32a.

[0094] Therefore, the strip 1 includes at least one second layer 4.

[0095] The second layer 4 is preferably made of a second polymer filament 40.

[0096] The second polymer filament 40 is preferably continuous. Furthermore, the second polymer filament 40 forms the surface layer of the strip 1. Therefore, if the matrix 2 is present, the second layer contacts the matrix 2 and / or the first layer 3 without penetrating the pores.

[0097] Therefore, the strip 1 may include, for example, a sandwich structure, in which a second layer 4 is superimposed on the matrix 2, and thus a first layer 3 is superimposed on or included between the second layer 4 and the matrix 2.

[0098] Alternatively, strip 1 may further include a fourth layer 6.

[0099] If present, the fourth layer comprises a third continuous polymer filament 60.

[0100] Furthermore, similar to the second polymer filament 40, the third polymer filament 60 also forms a surface layer of the strip 1. Then, the fourth layer 6 can contact the matrix 2 and / or the first layer 3 without penetrating the holes. Preferably, if the fourth layer 6 is present, it is placed on the opposite side of the second layer 4.

[0101] Then, the strip 1 may include a sandwich formed in the order of second layer 4, first layer 3 or matrix 2, matrix 2 or first layer 3 and fourth layer 6.

[0102] As an additional or alternative layer, strip 1 may also include a third layer 5.

[0103] If present, the third layer 5 is in contact with the matrix 2 on the opposite side of the first layer 3.

[0104] Therefore, advantageously, the third layer 5 also includes a mixture 30 that at least partially penetrates the pore.

[0105] Therefore, if there is a third layer 5 and a fourth layer 6, the fourth layer 6 can also contact the third layer 5 without penetrating the hole.

[0106] Therefore, the strip 1 may include a sandwich layer formed in the order of second layer 4, first layer 3, matrix 2, third layer 5 and fourth layer 6.

[0107] Alternatively, there can be two substrates 2, and one of each of layers 3 and 5. Then, the interlayer can be formed in the order of second layer 4, substrate 2, first layer 3, substrate 2, third layer 5, and fourth layer 6.

[0108] It is important to note that, according to the present invention, even at least a portion of the second polymer filament 40 and / or the third polymer filament 60 may define a corresponding unfolding axis 32a and a corresponding profile 33 similar to the first polymer filament 32.

[0109] In any case, it is advantageous to define the profile 33 on the cross-sectional plane 32b.

[0110] The cross-sectional plane 32b is preferably perpendicular to the unfolding axis 32a. Therefore, the cross-sectional plane 32b is essentially a virtual plane that defines the profile 33 on itself by cutting the polymer filaments 32, 40, 60 perpendicular to the unfolding axis 32a.

[0111] Contour 33 also defines a first extended area. This extended area is a portion of the two-dimensional space contained within contour 33.

[0112] Therefore, profile 33 is preferably inscribed in a circle. This circle is also defined on the cross-sectional plane 32b. Of course, this circle is usually a virtual geometric element in which profile 33 can be geometrically inscribed.

[0113] Furthermore, the circle itself defines a second extended area on the cross-sectional plane 32b. Therefore, the second extended area is determined by the two-dimensional space contained within the circle, which can be determined as known by the formula A = π*r. 2 get.

[0114] Advantageously, profile 33 does not have a shape corresponding to a circle.

[0115] In fact, advantageously, the first extended area is less than 90% of the second extended area. More specifically, preferably, the first extended area is less than 60% of the second extended area.

[0116] Therefore, contour 33 can be made according to different embodiments.

[0117] For example, contour 33 can be a convex figure. As is well known, a convex figure is a figure in which any line segment connecting any two points is completely contained within the figure itself.

[0118] Therefore, if the profile 33 is convex, it preferably defines a first dimension 33a and a second dimension 33b.

[0119] The first dimension 33a is essentially the largest dimension defined by the profile 33 in one direction. The second dimension 33b is also the largest dimension in the direction perpendicular to the first dimension 33a.

[0120] Preferably, the second dimension 33b is less than 90% of the first dimension 33a.

[0121] Even more specifically, the second dimension 33b can be 60% smaller than the first dimension 33a.

[0122] Additionally, the dimension can refer to a geometrically defined profile 33. For example, a convex profile 33 can have, for instance, a geometrically defined contour 33. Figure 6e The shape of the approximate equilateral triangle shown, or as... Figure 6d The shape shown is almost rectangular, and may even be slightly rounded on the sides.

[0123] Of course, in the case of a triangle, the first dimension 33a can be provided by the height, while the second dimension 33b can be provided by the base containing the height. In the case of a rectangle, dimensions 33a and 33b can correspond to the respective sides.

[0124] In other embodiments, contour 33 may alternatively be concave. Conversely, a shape exhibits concavity when at least one line segment connecting a pair of points of the shape does not entirely belong to the shape itself.

[0125] Therefore, if the profile 33 is concave, it preferably includes at least one convex portion 330. The convex portion 330 is part of the concave profile 33, which can be identified within the profile 33, so that the convex portion 330 is at least partially defined and has convex characteristics.

[0126] Therefore, similar to the convex profile 33, the convex portion 330 can also define the third dimension 330a and the fourth dimension 330b.

[0127] The third dimension 330a is essentially the largest dimension of the convex portion 330 defined in one direction. The fourth dimension 330 is also the largest dimension in the direction perpendicular to the third dimension 330a.

[0128] Preferably, the fourth dimension 330b is less than 90% of the third dimension 330a.

[0129] Even more specifically, the fourth dimension 330b can be 60% smaller than the third dimension 330a.

[0130] As previously stated, the dimension can refer to a geometrically defined convex portion 330. For example, the convex portion 330 of the profile 33 can have, for example, in... Figure 6h The shape shown is almost triangular, or as Figure 6g and Figure 6j The almost rectangular shape shown may have the following characteristics: Figure 6a The hypotenuse shown, or even as Figures 6b-6c The trapezoid shown.

[0131] Of course, in the case of a triangle, the first dimension 33a can be provided by the height, while the second dimension 33b can be provided by the base containing the height. In the case of a rectangle, dimensions 33a and 33b can correspond to the respective sides.

[0132] More generally, the concave profile 33 can be formed by two or more intersecting convex portions 330. Therefore, the concave profile 33 can define a cross shape with three to five points. For example, three, such as... Figure 6a and Figure 6c As shown, or four, such as Figure 6f and Figure 6i As shown, or even five, such as Figure 6b and Figure 6j As shown.

[0133] The present invention also enables the manufacture of a novel device 100 for manufacturing composite strips.

[0134] Appropriately, the new equipment 100 allows for the manufacture of strip 1 as described above.

[0135] Therefore, the equipment 100 includes at least a conveyor 101.

[0136] The conveyor 101 defines at least one support surface 101a. The support surface 101a is essentially a surface on which the strip 1 can be manufactured, for example, by deposition.

[0137] Conveyor 101 may include, for example, a conveyor belt component that slides along a closed path and is guided by a winder.

[0138] In any case, the device 100 preferably includes at least one first coaxial blowing device 102.

[0139] The first coaxial blowing device 102 is adapted to allow the deposition of the second layer 4 on the conveyor 101.

[0140] In addition, the device 100 also includes at least one unwinding device 103.

[0141] The unwinding device 103 is adapted to allow the deposition of matrix 2 on the second layer 4.

[0142] The device 100 also includes at least one first mixing device 104.

[0143] The first mixing device 104 is adapted to produce a first layer 3 to allow it to be deposited on the matrix 2.

[0144] Then, the first mixing device 104 preferably includes a first supply unit 1040 adapted to produce granules 31, a first polymerization unit 1041 adapted to produce first polymer filaments 32, and a first spinneret 1042 adapted to form the profile of the first polymer filaments 32 before conveying the first polymer filaments 32 toward the granules 31 to mix them to produce a mixture 30.

[0145] Advantageously, the spinneret 1042 includes a plurality of tubes 10.

[0146] Of course, tube 10 unfolds along the corresponding unfolding axis 32a.

[0147] Therefore, at least a portion of the tube 10 is defined by a profile 33 on the cross-sectional plane 32b, that is, the profile corresponds to the profile of the filament (in particular the first polymer filament 32) exiting the tube 10.

[0148] Therefore, similar to the polymer filaments 32, 40, and 60 mentioned above, the tube 10 itself is a substantially elongated element including a cavity through which liquid polymer can permeate to allow, for example, extrusion from the spinneret.

[0149] Therefore, tube 10 defines the unfolding axis 32a.

[0150] The unfolding axis 32a is essentially the axis around which the tube 10 unfolds. Furthermore, the unfolding axis 32a is the axis along which the polymer liquid can flow, and is therefore the axis along which the cavity defined by the tube 10 unfolds.

[0151] Therefore, tube 10 includes at least one inner surface 20.

[0152] The inner surface 20 is essentially closed. Furthermore, it unfolds around the unfolding axis 32a, as it actually faces the unfolding axis 32a.

[0153] Therefore, the inner surface 20 surrounds the cavity.

[0154] Furthermore, tube 10 defines a plurality of profiles 33. Profiles 33 are identical to each other. Moreover, they are arranged continuously along the unfolding axis 32a.

[0155] Therefore, the profile 33 is formed by the inner surface 20 substantially along the unfolding axis 32a and defines the overall shape of the cavity.

[0156] In particular, preferably, in this case, the profile 33 is also defined on the cross-sectional plane 32b.

[0157] Contour 33 also defines a first extended area. This extended area is a portion of the two-dimensional space contained within contour 33.

[0158] Therefore, the profile 33 is preferably inscribed in a circle defined on the cross-sectional plane 32b.

[0159] Furthermore, the circle itself defines a second extended area on the cross-sectional plane 32b. Therefore, the second extended area is determined by the two-dimensional space contained within the circle, which can be determined as known by the formula A = π*r. 2 get.

[0160] Advantageously, profile 33 does not have a shape corresponding to a circle.

[0161] In fact, advantageously, the first extended area is less than 90% of the second extended area. Even more specifically, preferably, the first extended area is less than 60% of the second extended area.

[0162] Therefore, even in the case of tube 10, profile 33 can be made according to different embodiments for at least a portion of polymer filaments 32, 40, 60 as described above.

[0163] In addition to what has already been described, tube 10 may also include an outer surface 40.

[0164] The outer surface 40 is also closed. Furthermore, the outer surface 40 unfolds around the inner surface 20. Then, the outer surface 40 surrounds the inner surface 20.

[0165] Furthermore, preferably, the outer surface 40, which faces the outside of the tube 10 and therefore does not contact the cavity, is connected to the inner surface 20 via the wall 50.

[0166] Therefore, wall 50 is surrounded by surfaces 20 and 40, and thus surfaces 20 and 40 define opposite faces of wall 50.

[0167] Therefore, the outer surface 40 can be cylindrical, such as... Figures 6a-6j , Figures 8a-8d and Figures 9a-9d As shown, the outer surface 40 can alternatively be profiled as the inner surface 20. In this way, surfaces 20 and 40 determine the constant thickness of the wall 50, for example, as... Figure 5 and Figures 7a-7d As shown in the image.

[0168] Of course, tube 10 can be used with other tubes 10 to form a tube assembly for use in the first spinneret 1042.

[0169] Therefore, the device 100 according to the invention also includes a first spinneret 1042, which includes a plurality of tubes 10 forming tube assemblies, which are extended along respective unfolding axes 32a, and at least a portion of these tubes define the profile 33 as described above.

[0170] Therefore, in various embodiments, the component may include a plurality of tubes 10 all defining the same profile 33, such as Figures 8a-8d As shown.

[0171] Alternatively, the component may include a plurality of tubes 10 defining corresponding, mutually distinct contours 33, such as Figures 7a-7d and Figures 9b-9d As shown.

[0172] Alternatively, the component may include a plurality of tubes 10 and a plurality of tubes each defining a circular profile, i.e., having a conventional profile according to known techniques, such as... Figure 7c and Figure 9a As shown.

[0173] Clearly, such tube assemblies enable the production of polymer filaments 32, 40, 60 with corresponding contours 33 or circular contours.

[0174] Of course, the present invention also includes device 100, which includes a first spinneret 1042, which together with a first supply unit 1040 realizes a multi-row coaxial meltblown device, the device including the components as described above according to different possible embodiments.

[0175] Therefore, the equipment 100 may also include a calender 107.

[0176] The calender 107 is adapted to crush the strip 1 in a manner that allows the mixture 30 to penetrate into the pores.

[0177] Of course, in order to manufacture the different layered strips 1 as described in the previous different embodiments, the apparatus 100 may further include a second mixing device 105.

[0178] Similar to the first mixing device 104, the second mixing device 105 is adapted to manufacture a third layer 5 to allow it to be deposited on the substrate 2.

[0179] Therefore, the second mixing device 105 preferably includes a second supply unit 1050 adapted to produce granules 31, a second polymerization unit 1051 adapted to produce first polymer filaments 32, and a second spinneret 1052 adapted to form the profile of the first polymer filaments 32 before conveying the first polymer filaments 32 toward the granules 31 to mix them to prepare a mixture 30, and in this respect at least partially includes other tubes 10.

[0180] Alternatively, or together with the second mixing device 105, the device 100 may include at least one second coaxial blowing device 106.

[0181] If present, the second coaxial air blowing device 106 is adapted to allow the deposition of a fourth layer 6 on the substrate 2 and / or on the first layer 3 and / or on the third layer 5.

[0182] To increase the penetration of mixture 30 into matrix 2, one or more of the coaxial blowing devices 102, 106 and mixing devices 104, 105 may be provided with a suction unit 1011. If present, the suction unit 1011 is positioned on opposite sides of the support surface 101a to crush layers 3, 4, 5, 6 and matrix 2 toward the support surface 101a.

[0183] The present invention also includes a new method for manufacturing composite strips (particularly strip 1).

[0184] The method includes at least: depositing a second layer 4 on a support surface 101a in a first deposition step I, depositing a first layer 3 or a matrix 2 on the second layer 4 in a second deposition step II, and then depositing the matrix 2 on the first layer 3 or depositing the first layer 3 on the matrix 2 in a third deposition step III.

[0185] The method then includes at least calendered layers 3 and 4 and a matrix 2 to manufacture strip 1.

[0186] If strip 1 also includes a fourth layer 6, such as Figures 12-13 As shown, preferably, in the second deposition step II, the matrix 2 is deposited on the second layer 4, in the third deposition step III, the first layer 3 is deposited on the matrix 2, and in the fourth deposition step IV, the fourth layer 6 is deposited on the first layer 3.

[0187] Therefore, the method may include depositing the third layer 5 on the matrix 2 in the fifth deposition step V.

[0188] Then, in the fourth deposition step IV, the fourth layer 6 can be deposited on the third layer 5.

[0189] In this case, during the calendering step, all layers 3, 4, 5, 6 and matrix 2 are calendered to produce strip 1.

[0190] The method may advantageously include depositing one or more of layers 3, 4, 5, 6 and matrix 2 obliquely relative to support surface 101a, such that they are neither perpendicular to nor parallel to support surface 101a. In this sense, for example, it is intended to convey one or more of polymer filaments 32, 40, 60, mixed or unmixed with particles 31, as well as polymer fibers, obliquely relative to support surface 101a.

[0191] In a preferred embodiment, only one or more of layers 3, 5 and matrix 2 are deposited at an angle relative to the support surface 101a.

[0192] Therefore, the method can also be provided to deposit one or more of layers 3, 4, 5, 6 and matrix 2 perpendicular to the support surface 101a on the support surface 101a.

[0193] In a preferred embodiment, layers 4 and 6 are deposited only perpendicular to the support surface 101a.

[0194] Furthermore, the method can be executed in the order previously described and as follows Figures 12-13 As shown in the figure; or the method can be implemented by first providing a second deposition step II, then a third deposition step III, and then a first deposition step I.

[0195] To complete this, layers 4, 3 and matrix 2 can then be flipped in the flipping station.

[0196] Then, the method may include flipping layers 4, 3 and matrix 2 in flipping step VI before performing the fifth deposition step V and the fourth deposition step IV. This process is particularly important in... Figure 14 It is shown in the figure.

[0197] As explained above, strip 1 does not need to include matrix 2.

[0198] In this case, in particular, strip 1 can be used to manufacture wiping materials.

[0199] In this case, preferably, the strip 1 may substantially comprise the first layer 3.

[0200] Therefore, the first layer 3 may substantially comprise a plurality of polymer filaments 32 defining the contour 33 as described above.

[0201] Alternatively, the first layer 3 may include a plurality of cellulose particles 31 mixed with the first polymer filament 32 to form a mixture 30.

[0202] Then, the strip 1 may also include a second layer 4 in contact with the first layer 3.

[0203] In addition, the strip 1 may include a third layer 5 in contact with the first layer and / or a fourth layer 6 in contact with the third layer 5 on the opposite side of the second layer 4.

[0204] Similar to the first layer 3, in this case, the third layer 5 may substantially comprise a plurality of polymer filaments 32 defining the outline 33 as described above. Alternatively, the third layer 5 may comprise a plurality of cellulose particles 31 mixed with the first polymer filaments 32 to form a mixture 30.

[0205] In order to manufacture this type of strip 1, the equipment 100 may not include certain components, such as the unwinding device 103.

[0206] In fact, preferably, the equipment 100 for manufacturing strip 1 in this form includes a conveyor 101, a first coaxial blowing device 102, a first polymerization unit 1041, a first spinneret 1042, and a calender 107.

[0207] Of course, such as Figures 15-16 As shown, the device 100 may also include a second polymerization unit 1051, a second spinneret 1052 and / or a second coaxial blowing device 106.

[0208] The apparatus 100 may also include a first mixing device 104 and / or a second mixing device 105. The first mixing device 104 and / or the second mixing device 105 (if present) respectively include at least a first polymerization unit 1041 having a first spinneret 1042 and a second polymerization unit 1051 having a second spinneret 1052.

[0209] In addition, such as Figures 17-19 As shown, the first mixing unit 104 and / or the second mixing unit 105 may also include a first supply unit 1040 and / or a second supply unit 1040 adapted to produce granules 31, respectively.

[0210] Then, in this embodiment, one or more of the spinnerets 1042, 1052 may be adapted to form the profile of the first polymer filament 32 before conveying the first polymer filament 32 toward the particles 31 to mix them to produce the mixture 30.

[0211] In this respect, one or more of the first coaxial air blowing device 102 and the second coaxial air blowing device 106 may also include a third supply unit 1020 and / or a fourth supply unit 1060, respectively.

[0212] Then, one or more of the first coaxial blowing device 102 and the second coaxial blowing device 106 may include a third polymerization unit 1021 having a third spinneret and a fourth polymerization unit 1061 having a fourth spinneret.

[0213] The third polymerization unit 1021 and the fourth polymerization unit 1061 are preferably similar to the first polymerization unit 1041 and the second polymerization unit 1051, and the third spinneret and the fourth spinneret are preferably similar to the first spinneret 1042 and the second spinneret 1052.

[0214] In this embodiment, the method for manufacturing strip 1 may also differ from the previously described method.

[0215] In fact, in this case, the method preferably includes a first deposition step I similar to the previous one, followed by a second deposition step II, in which the first layer 3 is deposited on the second layer 4.

[0216] The method then includes a calendering step, wherein the first layer 3 and the second layer 4 are calendered to produce strip 1.

[0217] In addition, the method may also include a fifth deposition step V and a fourth deposition step IV, in which a third layer 5 is deposited on the first layer 3, and in the fourth deposition step IV, a fourth layer 6 is deposited on the third layer 5.

[0218] In this case, calendering is performed on all layers 3, 4, 5, and 6 to produce strip 1.

[0219] The method may also include, for example Figure 16 As shown, one or more of layers 3, 4, 5, and 6 are deposited obliquely relative to the support surface 101a, so as to be neither perpendicular to nor parallel to the support surface 101a. Similarly, in this case, for example, it is intended to convey one or more of polymer filaments 32, 40, and 60, mixed or unmixed with particles 31, as well as polymer fibers, obliquely relative to the support surface 101a.

[0220] In addition, one or more of layers 3, 4, 5, and 6 may be deposited on the support surface 101a perpendicular to it.

[0221] The composite strip 1, along with related equipment and manufacturing method according to the present invention, achieves significant advantages.

[0222] In fact, composite strip 1 and related equipment and manufacturing methods are economically feasible.

[0223] Furthermore, the composite strip 1, along with the related equipment and manufacturing methods, enables high output to be achieved with cheaper production equipment and raw materials, especially without adhesives.

[0224] In fact, a particular advantage of the method according to the invention is that it utilizes the adhesiveness of the in-situ formed filaments to ensure structural integrity and particle control without the need for additional adhesive.

[0225] Furthermore, this method allows for very high yields of the resulting continuous composite absorbent tape, as it can be used at very high production rates, such as approximately 500 m / min, 700 m / min, or even 1000 m / min.

[0226] In addition, the width of the strip can be greater than approximately 1m, 3m, 5m, or 7m, in order to achieve a length greater than 500m. 2 / min, or 1000m 2 / min, or 2000m 2 / min, or 4000m 2 / min, or even 5000m 2 Total productivity per minute.

[0227] In summary, given the aforementioned advantages, composite strip 1 is highly effective because it does not compromise particle control before, during, or during production.

[0228] The invention can be modified to produce different versions that fall within the scope of the inventive concept defined by the claims.

[0229] In this context, all details can be replaced by equivalent elements, and any material, shape, and size can be used.

Claims

1. A composite strip (1), the composite strip (1) comprising: - At least a first layer (3), which includes a plurality of continuous first polymer filaments (32) and defines a spreading axis (32a) and a plurality of identical profiles (33) arranged at least partially along the spreading axis (32a); - A second layer (4) of a continuous second polymer filament (40), the second polymer filament (40) forming the surface layer of the strip (1) and being placed in contact with the first layer (3); Its features - The profile (33) is defined on a cross-sectional plane (32b) perpendicular to the unfolding axis (32a), the profile (33) defines a first extended area on the cross-sectional plane (32b) and can be inscribed in a circle, the circle is defined on the cross-sectional plane (32b) and defines a second extended area on the cross-sectional plane (32b); - The first extended area is less than 90% of the second extended area.

2. The strip (1) according to claim 1, wherein the first extension area is less than 60% of the second extension area.

3. The strip (1) according to claim 1, wherein the profile (33) is convex and defines at least a first dimension (33a) and a second dimension (33b), the second dimension (33b) being perpendicular to the first dimension (33a) and less than 90% of the first dimension (33a).

4. The strip (1) according to claim 1, wherein the profile (33) is concave and includes at least one convex portion (330) identifiable within the profile (33), such that the convex portion (330) is defined by at least a portion of the profile (33) and defines at least a third dimension (330a) and a fourth dimension (330b), the fourth dimension (330b) being perpendicular to the third dimension (330a) and less than 90% of the third dimension (330a).

5. The strip (1) according to claim 3 or 4, wherein the second dimension (33b) is less than 60% of the first dimension (33a) or the fourth dimension (330b) is less than 60% of the third dimension (330a).

6. The strip (1) according to claim 1 or 2, further comprising: - A third layer (5), which is in contact with the first layer (3) and also includes a plurality of the first polymer filaments (32), and / or - A fourth layer (6) of a continuous third polymer filament (60), the third polymer filament (60) forming the surface layer of the strip (1) and positioned on the opposite side of the second layer (4) to contact the third layer (5).

7. The strip (1) according to claim 6, wherein at least a portion of the second polymer filament (40) and / or the third polymer filament (60) further defines the corresponding unfolding axis (32a) and the corresponding profile (33).

8. The tape (1) according to claim 6, wherein the first layer (3) and / or the third layer (5) further comprises a plurality of cellulose particles (31), the cellulose particles (31) being mixed with the first polymer filament (32) to produce a mixture (30) contained in the first layer (3) and / or the third layer (5).

9. An apparatus (100) for manufacturing the strip (1) according to any one of claims 1-8, said apparatus (100) comprising at least: - A conveyor (101) defining a support surface (101a) on which the strip (1) is manufactured. - At least one first coaxial air blowing device (102) adapted to allow the deposition of the second layer (4) on the conveyor (101), - A first polymerization unit (1041) suitable for producing the first polymer filament (32) and a first spinneret (1042) suitable for forming the profile of the first polymer filament (32), the first polymer filament (32) forming the first layer (3); and - A calender (107) adapted to crush the strip (1); Its features - The first spinneret (1042) includes a plurality of tubes (10) that extend along the respective unfolding axis (32a) and at least a portion of these tubes are defined by the profile (33) defined on the cross-sectional plane (32b).

10. The device (100) according to claim 9, further comprising: - A second polymerization unit (1051) and a second spinneret (1052) adapted to produce the first polymer filament (32), the second spinneret (1052) being adapted to form the profile of the first polymer filament (32) forming the third layer (5), and including other tubes (10) besides the plurality of tubes (10); and / or - At least one second coaxial blowing device (106) adapted to allow the fourth layer (6) to be deposited on the first layer (3) and / or the third layer (5).

11. The apparatus (100) according to claim 9 or 10, further comprising a first mixing device (104) and / or a second mixing device (105), each comprising a first polymerization unit (1041) having a first spinneret (1042) and a second polymerization unit (1051) having a second spinneret (1052), wherein the first mixing device (104) and / or the second mixing device (105) each comprise a first supply unit (1040) and / or a second supply unit (1040) adapted to produce granules (31) and one or more of the spinnerets (1042, 1052) adapted to form the profile of the first polymer filaments (32) prior to conveying the first polymer filaments (32) toward the granules (31) to mix them to prepare a mixture (30).

12. A method for manufacturing strip (1) according to any one of claims 1-8, the method comprising: -(I) Deposit the second layer (4) onto the support surface (101a); -(III) Deposit the first layer (3) onto the second layer (4); - Calender at least the layers (3, 4) to manufacture the strip (1).

13. The method of claim 12, further comprising: -(V) Deposit the third layer (5) on the first layer (3); -(IV) Deposit the fourth layer (6) onto the third layer (5); - Calender the layers (3, 4, 5, 6) to manufacture the strip (1).

14. The method according to claim 12 or 13, wherein one or more of the layers (3, 4, 5, 6) are deposited obliquely relative to the support surface (101a) so as to be neither perpendicular to nor parallel to the support surface (101a).

15. The method according to claim 12 or 13, wherein one or more of the layers (3, 4, 5, 6) are deposited perpendicular to the support surface (101a) on the support surface (101a).

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