Structures containing particles and their manufacturing methods

Abstract

The present invention provides a structure comprising particles such as superabsorbent polymer particles (SAP particles) (e.g., fibrous structures, such as absorbent materials, such as absorbent core materials), and a method thereof for manufacturing the same.

Description

Technical Field

[0001] This invention relates to structures comprising particles, such as fibrous structures, such as absorbent materials, such as absorbent core materials, and more specifically to fibrous structures comprising particles such as superabsorbent polymer particles (SAP particles), and methods for manufacturing the same. Background Technology

[0002] For many hygiene applications, it is advantageous to combine particles of different sizes, shapes, densities, Stokes numbers, and / or masses (such as SAP particles) into a single structure (e.g., a fibrous structure, such as an absorbent material, like an absorbent core material) to meet all desired performance requirements. These desired performance requirements may include a combination of mechanical properties (such as softness and / or flexibility) and fluid handling properties used to prevent leakage and keep skin dry upon contact with the structure and / or products containing the structure.

[0003] In addition to incorporating particles into the structure, formulators also incorporate non-particulate solid additives, such as fibers, like pulp fibers.

[0004] Known non-limiting examples of solid additives (particulate and / or non-particulate) used in structures (e.g., fibrous structures, such as absorbent core materials) include fibers, such as: 1) pulp fibers for providing absorbency, flexibility, and / or softness to the structure (e.g., fibrous structures, such as absorbent core materials); 2) SAP particles for providing sufficient liquid retention capacity (e.g., urine or menstrual flow) to the structure (e.g., fibrous structures, such as absorbent core materials); 3) fragrance particles for producing aroma; 4) odor control particles for controlling odor; 5) abrasive particles for providing abrasive properties to the structure (e.g., fibrous structures, such as absorbent core materials); and 6) other inorganic and / or organic particles. However, known methods of incorporating solid additives of fibers and / or particles of different sizes, shapes, and densities, and / or solid additives of fibers and / or particles exhibiting different Stokes numbers, such as pulp fibers and SAP particles, into a single structure (e.g., fibrous structures, such as absorbent core materials) have been less successful due to negative factors associated with the resulting structure. It is believed that the problems associated with the use of known methods for incorporating such solid additives into such structures involve at least partly the use of mixed solid additive streams in methods for manufacturing such structures, such as air streams comprising mixed solid additives (e.g., fibers, such as pulp fibers, and particles, such as SAP particles). Such mixed solid additive streams, containing mixtures of solid additives of different sizes, shapes, and / or densities and / or different Stokes numbers, result in different trajectories for the different solid additives based on their size, shape, density, and / or Stokes number, and lead to the formation of unacceptable structures (e.g., fibrous structures, such as absorbent core materials) because fibrous structures can exhibit higher densities, e.g., greater than 0.2 g / cm³. 3 And / or different solid additives may not be adequately bound, distributed and / or captured within the structure.

[0005] Existing technology Figure 1A Examples of known methods for incorporating solid additives (i.e., particulate and non-particulate solid additives, such as fibers) into a single structure (e.g., a fibrous structure, such as an absorbent material, such as an absorbent core material) are shown. (See prior art) Figure 1AAs shown, method 10 (commonly referred to as a co-forming method and / or spinning method) includes two meltblown polymer filament streams 12 (each formed by extruding molten thermoplastic material into a converging high-speed gas via a die 14) and a mixed solids additive stream 16 comprising a mixture of fibers 18 (e.g., pulp fibers) and particles 20 (e.g., SAP particles) that impinge on the two meltblown filament streams 12 at their convergence point. The mixed solids additive stream 16 is injected into the two meltblown filament streams 12 at the impingement zone 22 where they converge. The fibers 18 and particles 20 exhibit different sizes, shapes, and / or densities, as well as different Stokes numbers. Each of the two meltblown filament streams 12 comprises multiple meltblown filaments 24. Both the two meltblown filament streams 12 and the mixed solids additive stream 16 are open to ambient air and pressure. In other words, the fact that flows 12 and 16 are not in a controlled and / or closed environment and / or are not enclosed in a shell may have a negative impact on the method, namely, on the structure formation and hygiene of the method.

[0006] At least in part, due to the difference in Stokes numbers between fibers 18 (e.g., wood pulp fibers exhibiting a relatively low Stokes number) and particles 20 (e.g., SAP particles exhibiting a relatively high Stokes number), the airflow conveying and delivering the mixed solids additive stream 16 to the impact zone 22 cannot prevent at least a portion of the particles 20 from ultimately landing on the top T and bottom B of the structure 26 (e.g., a fibrous structure, such as an absorbent material), as in the prior art. Figure 1B As shown. Because particles 20 exhibit a higher (e.g., significantly higher) Stokes number than fibers 18, particles 20 are prone to random trajectories and are therefore an uncontrolled distribution of particles. This results in particles 20 being present at higher concentrations near the upstream and downstream edges of the mixed solids additive stream 16, unlike fibers 18 which tend to be more uniformly dispersed or more concentrated in the inner portion of the mixed solids additive stream 16. Concentrating particles 20 (e.g., SAP particles) at the top T and bottom B of structure 26 poses safety and hygiene problems because loose particles 20 are easily separated from structure 26 because they are not adequately enclosed within the multiple intertwined filaments 24 of structure 26. Furthermore, structures produced by this known prior art method (e.g., fiber structures, such as absorbent materials, e.g., absorbent core materials) exhibit random arrangement of particles within and / or on the resulting structure.

[0007] The above regarding existing technology Figure 1A The prior art method 10 and prior art shown Figure 1B and Figure 1CThe problems with the resulting structure 26 shown can be addressed by modifying the process conditions to ensure a higher concentration of meltblown filaments 24 at one or more of the top T and bottom B of structure 26, to adequately retain the particles 20 within structure 26 without adversely affecting other desired properties of structure 26. However, these modifications fail to address the uncontrolled distribution and random arrangement of particles 20 in the composite fluid flow and in the final resulting structure 26. Furthermore, the higher concentration of meltblown filaments 24 at the top T and / or bottom B of structure 26 can reduce the integrity and / or mixing of particles and filaments throughout structure 26, and / or prevent the fibers 18 and / or particles 20 from detaching from structure 26 during material processing, such as winding, slitting, unwinding, and conversion into finished absorbent materials, such as finished absorbent core materials.

[0008] Additionally, if the concentration (meaning amount and / or level, such as mass and / or weight percentage per unit volume) of the meltblown filament 24 on one or both sides (top T and / or bottom B) is too high, the meltblown filament 24 can create a fluid barrier at one or more surfaces of the structure. Such a fluid barrier will increase fluid collection time and / or reduce the performance of the structure 26, such as its absorption performance, by inhibiting the structure's ability to absorb fluid.

[0009] Based on the foregoing, existing technology Figure 1A Method 10 and existing technology Figure 1B The resulting structure 26 shown in the diagram exhibits negative results that need to be addressed.

[0010] Similarly, existing technology Figure 2A Method 10 shown also exhibits negative results that need to be addressed. (Prior art) Figure 2A Method 10 shown is another example of a known method for incorporating solid additives into a single structure (e.g., a fibrous structure, such as an absorbent material, like an absorbent core material). This is consistent with the above and existing techniques. Figure 1A Unlike known methods, existing technologies Figure 2A The method 10 shown is performed in a controlled and / or enclosed environment and / or is enclosed or substantially enclosed in a housing 28. As in the prior art... Figure 2A As shown, method 10 includes a single meltblown polymer filament stream 12 formed by extruding molten thermoplastic material via a filament source 30 (in this case, a multi-row capillary die) and at least one mixed solids additive stream 16, which comprises a mixture of fibers 18 (e.g., pulp fibers) derived from a fiber source (not shown) and particles 20 (e.g., SAP particles) derived from a particle source (not shown). [Prior Art] Figure 2AMethod 10 may include one or more solid additive streams 32 (e.g., prior art) Figure 2A The fiber stream (shown) and / or mixed solid additive stream 16 (e.g., fibers 18 and particles 20) are added to a single meltblown polymer filament stream 30 comprising multiple meltblown filaments 24. Fibers 18 and particles 20 exhibit different sizes, shapes, and / or densities, as well as different Stokes numbers. Therefore, fibers 18 and particles 20 also exhibit differences in their inertia. Thus, a relatively straight path is required between the mixing point and the collection device to achieve good mixing of fibers 18 and particles 20. In the prior art... Figure 2A In the case of method 10, the path traveled by the mixed solid additive stream 16 is not relatively straight due to one or more bends in the path. Due to different Stokes numbers, such bends lead to separation between fibers 18 and particles 20, resulting in poor mixing of fibers 18 and particles 20 within the mixed solid additive stream 16, and are considered to be an uncontrolled distribution of particles 20, which leads to random arrangement of particles within and / or on the resulting structure 26.

[0011] In addition to existing technologies Figure 2A In addition to the poor mixing of fibers 18 and particles 20 in method 10, the prior art Figures 2B to 2D The image shown is from the prior art. Figure 2A The structure 26 obtained by method 10 is on one side (e.g., prior art). Figure 2B and Figure 2C The top T side or part of the resulting structure 26 shown is from the prior art. Figure 2D The bottom B side (or part thereof) of the resulting structure 26 shown contains substantially all of the particles 20.

[0012] Although individual SAP particles may follow slightly different trajectories depending on their respective individual size, shape, density, and Stokes number, both small and large SAP particles still separate entirely from the fiber during structure formation, resulting in negative outcomes in the structure.

[0013] Based on the foregoing, existing technology Figure 2A Method 10 and existing technology Figure 2B The resulting structure 26 shown in the diagram exhibits negative results that need to be addressed.

[0014] Commercially available SAP particles are typically manufactured in a manner that results in a large particle size distribution. Typical particle sizes range from 30 μm to 800 μm. The presence of both large and small particles within SAP particles can be advantageous. The benefit of smaller particles is generally a faster absorption rate due to a higher surface area to volume ratio. However, they tend to have a smaller capacity (liquid stored per gram of SAP material) and also tend to cause gel blockage. Gel blockage is detrimental to absorbent core materials because it reduces permeability and blocks the channels for fluid diffusion within the blocked absorbent structure, leading to poor absorption and increasing the risk of fluid spillage or a wet feeling when worn.

[0015] Conversely, the advantage of larger SAP particles is that they tend to have a higher capacity per gram, making them more cost-effective for storing a certain amount of liquid, and they are also less likely to cause gel blockage. However, their absorption rate tends to be lower.

[0016] The difference in absorption performance between small and large particles makes SAP particle size distribution a key factor in the fluid handling performance of absorbent products. (Refer to typical fluid handling performance optimization based on g SAP / pad and z-direction concentration gradient. Using only absolute levels of SAP particles and concentration in the z-direction cannot resolve the inherent trade-off between small and large particles.)

[0017] To obtain optimal performance from a given particle size distribution, i.e., to achieve maximum absorption rate advantage and g / g capacity while preventing gel blockage, it would be highly advantageous to separate small particles (for collection speed, but prone to gel blockage) from large particles.

[0018] In particular, it is highly advantageous to provide SAP particles with a wide size distribution and then introduce them into the filament matrix, such that smaller particles are preferentially positioned towards one side (e.g., the bottom), where gel blockage is less significant, and larger particles are preferentially positioned towards the opposite side (e.g., the top), where permeability is important and the significant presence of small SAP particles can adversely affect permeability and performance. This is especially true in product applications where fluid enters in several intrusions or over a longer period, where gel blockage of one intrusion can prevent subsequent intrusions from being well absorbed into the structure, or in the case of menstrual products, where a wet feeling can be left if the fluid is preferentially absorbed at the top, closer to the body. The effect of particle size distribution will be distinct from the simple effect of controlling the SAP concentration gradient in the z-direction, i.e., a structure with a more uniform particle size distribution at any given plane in the z-direction of the substrate.

[0019] Fiber structures incorporating SAP particles are known in the art. For example, prior art co-molding methods for manufacturing such fiber structures using converging air and die-cutting techniques are known in the art. However, a problem associated with such known fiber structures and prior art methods is that the random distribution of SAP particles throughout such known fiber structures (especially in the z-direction, e.g., throughout the thickness of such known fiber structures) is substantially uniform relative to the average particle size of the SAP particles. In other words, large and small SAP particles are mixed and randomly and substantially uniformly distributed throughout such known fiber structures (especially in the z-direction, e.g., throughout the thickness of such known fiber structures). This random and substantially uniform distribution throughout known fiber structures leads to negative consequences related to the absorbency of such known fiber structures. In other words, the presence of smaller SAP particles near one side of the fiber structure (i.e., the side of the fiber structure intended to receive the initial intrusion of liquids such as urine and / or menstruation when used as an absorbent core) causes the smaller SAP particles to absorb liquid and create gel blockage, which at least prevents some (if not a large amount) of the liquid from further penetrating into the thickness of the fiber structure used as an absorbent core.

[0020] Formulators have attempted to correct for these negative consequences associated with such known fiber structures by depleting SAP particles on that side of the known fiber structure, resulting in fewer SAP particles (both large and small) near the side of the fiber structure that receives the initial intruder, thus mitigating gel clogging issues. However, throughout the thickness of the fiber structure, the SAP particles continue to consist of a random and substantially homogeneous mixture of large and small SAP particles, lacking a particle size gradient within the known fiber structure's thickness. This still results in suboptimal absorption performance when the fiber structure is used as an absorbent core. Another issue with completely removing SAP particles from the body-facing side surface is the potential drying benefits that SAP particles can deliver when worn, especially when used moderately near the body-article interface.

[0021] Another problem seen in the prior art methods described above is the integration of mixed solid additives (such as two or more solid additives that differ in size, shape, density, and / or Stokes number, for example, fibers (such as pulp fibers) and particles (such as SAP particles)) into structures (such as fibrous structures, such as absorbent materials, such as absorbent core materials). Such known methods cannot effectively control the distribution of solid additives (e.g., high Stokes number solid additives, especially particles) within the resulting structure and / or cannot effectively control the concentration of such solid additives throughout the resulting structure, thereby causing the particles to be arranged in a non-random manner within the resulting structure.

[0022] Therefore, there is a need for a method for incorporating particles (such as SAP particles) into structures (such as fibrous structures, e.g., absorbent materials, such as absorbent core materials), that provides a controlled distribution of particles to produce a structure comprising a non-random arrangement of particles within the structure, and / or provides a non-random arrangement of the concentration of such particles throughout the resulting structure and a resulting structure that overcomes the negative consequences associated with known fibrous structures containing particles. Summary of the Invention

[0023] This invention addresses the aforementioned need by providing a novel method for incorporating multiple particles into multiple fibrous elements (e.g., filaments and / or fibers, such as a flow of multiple filaments, or a fluid flow comprising multiple fibrous elements (e.g., filaments)). This method involves mixing and / or adding the flow of multiple particles (e.g., a fluid flow comprising multiple particles) to the fluid flow comprising multiple fibrous elements (e.g., filaments) using a controlled particle distribution method, thereby generating a non-random arrangement of the multiple particles in the resulting composite fluid flow comprising the multiple particles and the multiple fibrous elements (e.g., multiple filaments). Furthermore, the resulting structure (e.g., a fibrous structure, such as an absorbent material, or an absorbent core material) formed when the composite fluid flow is collected onto a collection device also exhibits a non-random arrangement of the multiple particles in the resulting structure.

[0024] One solution to the aforementioned problem is a novel method for introducing (e.g., mixing and / or adding) particles (e.g., a fluid flow comprising multiple particles (particle flow)) in a controlled distribution to a fluid flow comprising multiple fibrous elements (e.g., multiple filaments) (fiber element flow and / or filament flow). This controlled distribution is achieved, for example, by controlling the angle and / or velocity at which multiple particles from the fluid flow comprising the multiple particles are introduced (mixed and / or added) into the filament flow, thereby forming a composite fluid flow comprising a non-random arrangement of particles in the filament flow. If this composite fluid flow is collected on a collection device, a resulting structure comprising a non-random arrangement of particles in the structure is formed, such as a fibrous structure, such as an absorbent material, such as an absorbent core material. In one example, this novel method manufactures a fibrous structure comprising particles (e.g., SAP particles) present within the fibrous structure, particularly in the z-direction of the fibrous structure (in other words, the thickness of the fibrous structure), such that a gradient (e.g., a continuous gradient) of the particle size of the SAP particles exists within at least a portion of the thickness of the fibrous structure. For example, the fiber structure includes SAP particles present within its thickness, such that when the fiber structure is used as the absorbent core in an absorbent article, a higher concentration (meaning amount and / or level, e.g., mass and / or weight percentage per unit volume) of larger-sized SAP particles is present near the side of the fiber structure that will receive the initial intrusion of the fluid (e.g., urine and / or menstrual flow) relative to smaller-sized SAP particles and / or a small amount of smaller-sized SAP particles in total size. Through this arrangement of SAP particle sizes, gel blockage is mitigated and / or inhibited due to the relatively small and / or practically minimal amount of smaller-sized SAP particles present on this side of the fiber structure.

[0025] In one example of the invention, a method for forming a composite fluid flow is provided, the method comprising the steps of: mixing (e.g., blending, co-forming) a first fluid flow comprising a plurality of fiber elements (e.g., filaments and / or fibers, such as filaments, such as water-insoluble fiber elements, such as water-insoluble filaments) with a second fluid flow comprising a plurality of first particles (e.g., SAP particles), such that a composite fluid flow (including the fiber elements and the first particles) exhibiting a non-random arrangement of the plurality of first particles in the composite fluid flow is formed substantially simultaneously with the collection of the composite fluid flow on a collection device; and optionally, the composite fluid flow exhibiting a non-random arrangement of the plurality of first particles in the composite fluid flow (including the fiber elements and the first particles) is collected substantially simultaneously with the collection of the composite fluid flow on a collection device; and optionally, the composite fluid flow is collected on a collection device, the collection device comprising a nonwoven fiber web material, such as a pre-existing nonwoven fiber web material, such as a top sheet, such as a secondary top sheet, such that a fiber structure exhibiting a non-random arrangement of the plurality of first particles in the fiber structure is formed.

[0026] In another example of the present invention, a method for manufacturing a fiber structure is provided, the method comprising the following steps:

[0027] a. Provide multiple filaments;

[0028] b. Provide a plurality of particles, wherein the particles exhibit a wide range of particle size distributions, for example, wherein the plurality of particles exhibit an average particle size distribution of about 300 μm and / or wherein the plurality of particles exhibit a particle size range of about 45 μm to about 710 μm and / or greater than 250 μm and / or greater than 400 μm and / or greater than 500 μm and / or greater than 600 μm and / or greater than 700 μm (e.g., the plurality of particles may include particles with a particle size of about 700 μm and particles with a particle size of about 45 μm); and

[0029] c. Blend the multiple filaments with the multiple particles;

[0030] d. Collect multiple filaments and multiple particles in a collecting device to form a fiber structure, such that the multiple particles are dispersed in the fiber structure in a non-random arrangement (e.g., based on particle size, shape, density, mass, Stokes number).

[0031] In another example of the invention, a structure, such as a fiber structure, manufactured by the method of the invention is provided.

[0032] In another example of the invention, a structure, such as a fiber structure, is provided, comprising a plurality of fiber elements (e.g., filaments and / or fibers, such as filaments) and a plurality of first particles (e.g., SAP particles), wherein the plurality of first particles are arranged in a non-random manner in the structure (e.g., the fiber structure).

[0033] In another example of the invention, a fiber structure comprising multiple filaments and multiple particles is provided, wherein the multiple particles exist in the fiber structure in a non-random arrangement (e.g., based on particle size, shape, density, mass, Stokes number).

[0034] In another example of the invention, a method according to any of the methods described herein is provided, wherein the diameter (e.g., the average diameter of the filaments as measured according to the average diameter testing method described herein) varies in the fiber structure, for example, by layer and / or by the type of particles contained and / or by the warp beam on which the filaments are laid (containing or not containing particles).

[0035] In another example of the present invention, a method for manufacturing a fibrous structure containing particles is provided, the method comprising the following steps:

[0036] a. Adding a plurality of first particles to a first stream of a first filament having a first average diameter to form a first composite material stream;

[0037] b. Collect the first composite material stream onto a collection device to form the first layer of the fiber structure;

[0038] c. Adding a plurality of second particles to a second filament having a second average diameter different from the first average diameter to form a second composite material flow;

[0039] d. The second composite material flow is directly collected onto the first layer of the fiber structure to form a layered fiber structure comprising the first layer and the second layer formed by the second composite material flow.

[0040] In yet another example of the invention, the fiber structure exhibits a density of less than 0.2 g / cm³. 3 and / or less than 0.15 g / cm³ 3 and / or less than 0.1 g / cm³ 3 Total fiber structure (fiber elements and particles) density.

[0041] Therefore, the present invention provides a novel method for manufacturing composite fluid flows, the composite fluid flows including fibrous elements (e.g., filaments) and particles (e.g., SAP particles), and novel structures, such as fibrous structures, such as absorbent materials, such as absorbent core materials, manufactured by such composite fluid flows and / or methods. Attached Figure Description

[0042] Figure 1A This is a schematic diagram illustrating an example of a prior art method for combining granular and fibrous elements;

[0043] Figure 1B It is possible Figure 1A A schematic diagram of an example of a prior art fiber structure produced by a prior art method;

[0044] Figure 1C It is possible Figure 1A A schematic diagram of another example of a prior art fiber structure produced by a prior art method;

[0045] Figure 2A This is a schematic diagram of an example of another prior art method for combining granular and fibrous elements;

[0046] Figure 2B It is possible Figure 2A A schematic diagram of an example of a prior art fiber structure produced by a prior art method;

[0047] Figure 2C It is possible Figure 2AA schematic diagram of another example of a prior art fiber structure produced by a prior art method;

[0048] Figure 2D It is possible Figure 2A A schematic diagram of another example of a prior art fiber structure produced by a prior art method;

[0049] Figure 3A This is a schematic diagram illustrating an example of the method according to the present invention;

[0050] Figure 3B It is possible Figure 3A A schematic diagram of particle size distribution produced by the method;

[0051] Figure 3C It is possible Figure 3A A schematic diagram of an example of the fiber structure produced by the method according to the present invention;

[0052] Figure 4A This is a schematic diagram of another example of the method according to the present invention;

[0053] Figure 4B It is possible Figure 4A A schematic diagram of particle distribution based on particle size generated by the method;

[0054] Figure 4C It is possible Figure 4A A schematic diagram of an example of the fiber structure produced by the method according to the present invention;

[0055] Figure 5A This is a schematic diagram of another example of the method according to the present invention;

[0056] Figure 5B It is possible Figure 5A A schematic diagram of an example of the fiber structure produced by the method according to the present invention;

[0057] Figure 5C It is possible Figure 5A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0058] Figure 5D It is possible Figure 5A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0059] Figure 6A This is a schematic diagram of another example of the method according to the present invention;

[0060] Figure 6B It is possible Figure 6A A schematic diagram of an example of the fiber structure produced by the method according to the present invention;

[0061] Figure 6C It is possible Figure 6A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0062] Figure 6D It is possible Figure 6A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0063] Figure 7A This is a schematic diagram of another example of the method according to the present invention;

[0064] Figure 7B It is possible Figure 7A A schematic diagram of particle distribution based on particle size generated by the method;

[0065] Figure 7C It is possible Figure 7A A schematic diagram of an example of the fiber structure produced by the method according to the present invention;

[0066] Figure 8A This is a schematic diagram of another example of the method according to the present invention;

[0067] Figure 8B It is possible Figure 8A A schematic diagram of an example of the fiber structure produced by the method according to the present invention;

[0068] Figure 8C It is possible Figure 8A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0069] Figure 8D It is possible Figure 8A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0070] Figure 8E It is possible Figure 8A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0071] Figure 8F It is possible Figure 8A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0072] Figure 8G It is possible Figure 8A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0073] Figure 8H It is possible Figure 8AA schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0074] Figure 8I It is possible Figure 8A A schematic diagram of another example of the fiber structure according to the invention produced by the method;

[0075] Figure 9 This is a schematic diagram illustrating an example of the method according to the present invention;

[0076] Figure 10 This is a schematic diagram illustrating an example of the method according to the present invention;

[0077] Figure 11 This is a schematic diagram illustrating an example of the method according to the present invention;

[0078] Figure 12 This is a particle size distribution curve of an example particle according to the present invention;

[0079] Figure 13 This is a schematic diagram of an example of the method according to the present invention, which is used in method embodiments 1 to 6;

[0080] Figure 14A The SAP particle size distribution curve (x-axis = depth (mm) and y-axis = average volume (mm)) of the fiber structure manufactured by method Example 1a is measured according to the μCT test method described herein. 3 The image is shown.

[0081] Figure 14B The SAP particle size distribution curve (x-axis = depth (mm) and y-axis = total volume (mm)) of the fiber structure manufactured by method example 1a is measured according to the μCT test method described herein. 3 The image is shown.

[0082] Figure 14C This is a schematic diagram of the fiber structure manufactured by method embodiment 1a;

[0083] Figure 15A The SAP particle size distribution curve (x-axis = depth (mm) and y-axis = total volume (mm)) of the fiber structure manufactured by method example 1b is measured according to the μCT test method described herein. 3 The image is shown.

[0084] Figure 15B The SAP particle size distribution curve (x-axis = depth (mm) and y-axis = average volume (mm)) of the fiber structure manufactured by method Example 1b is measured according to the μCT test method described herein. 3 The image is shown.

[0085] Figure 16 This is a magnified image of a portion of the scale, showing SAP particles and pulp fibers;

[0086] Figure 17A The image on the left shows a fiber structure manufactured according to the present invention, compared to a contrasting fiber structure on the right (which shows many more smaller SAP (AGM) particles closer to the top, which causes gel blockage during liquid absorption from the top). This contrasts with the larger SAP (AGM) particles closer to the top (fewer or no small SAP particles near the top), which prevents less gel blockage; and

[0087] Figure 17B It shows from Figure 17A The image shows the tape peeling portion at the top (T) of the fiber structure (the fiber structure of the present invention) on the left side of the middle, and illustrates the peeling from the tape. Figure 17A Image of the tape peeled portion at the bottom (B) of the fiber structure (fiber structure of the present invention) on the left side of the middle. Detailed Implementation

[0088] definition

[0089] As used herein, with respect to 1) the presence of particles in a composite fluid flow, such as the presence of particles in a composite fluid flow comprising multiple fibrous elements (e.g., filaments and / or fibers, such as filaments) and multiple particles, "non-random arrangement" means a) particles present in the composite fluid flow at different longitudinal thickness locations based on particle characteristics selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixed characteristics, such as size and / or Stokes number; and / or b) particles present in the composite fluid flow in a longitudinal gradient based on particle characteristics selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixed characteristics; and / or c) Particles are present in the composite fluid flow at one or more localized regions within the longitudinal thickness of the composite fluid flow (less than the entire or substantially the entire longitudinal thickness of the composite fluid flow); and / or d) Particles are present in the composite fluid flow at varying concentrations (amount and / or levels, e.g., weight percentage, e.g., based on particle composition) within the longitudinal thickness of the composite fluid flow; and / or e) Particles are present in the composite fluid flow at one or more localized regions in the transverse dimension of the composite fluid flow (less than the entire or substantially the entire transverse dimension of the composite fluid flow, e.g., particles present in one or more longitudinal stripes); and / or regarding 2) In the presence of multiple fiber elements (e.g., filaments and / or fibers) The presence of particles in structures (e.g., filaments) and multiple particles (e.g., fibrous structures, such as absorbent materials, such as absorbent core materials) is described as "non-random arrangement," meaning that a) particles exist in the fiber structure at different thickness locations in the z-direction based on particle properties selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixed properties, such as size and / or Stokes number; and / or b) particles exist in the fiber structure with a z-direction gradient based on particle properties selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixed properties; and / or c) particles exist in the fiber structure at one or more local regions within the z-direction thickness of the fiber structure. (less than the entire or substantially the entire z-direction thickness of the fiber structure); and / or d) particles exist in the fiber structure at different concentrations (amount and / or levels, e.g., weight percentage, based on particle composition) in the z-direction thickness of the fiber structure; and / or e) particles exist in the fiber structure at one or more local regions in the transverse dimension of the fiber structure (less than the entire or substantially the entire transverse dimension of the fiber structure, e.g., particles exist in one or more longitudinal stripes); and / or f) particles exist in the structure (e.g., the fiber structure) with the following distribution: i) z-direction distribution such that the particles within the structure exhibit a z-direction gradient based on the physical properties of the particles (e.g., size, shape, mass, and / or Stokes number);2) A z-direction distribution and / or an xy-direction distribution, such that particles within the structure (e.g., a fibrous structure) exist at different concentration levels (e.g., in the z-direction and / or xy-direction); or 3) an xy-direction distribution, such that particles exist in discrete regions within the structure, which may also exhibit a z-direction distribution of particles within the region, such that the particles exhibit a z-direction gradient based on their physical properties (e.g., size, shape, mass, and / or Stokes number), and / or such regions may also exhibit different concentration levels of particles in different regions.

[0090] As used herein, "fiber structure" means a structure comprising multiple filaments (e.g., multiple filaments and / or multiple fibers). In addition to filaments, fiber structures may include other materials, such as granules (e.g., SAP granules) and / or pulp fibers. In one example, a fiber structure according to the invention means an ordered arrangement of filaments and granules within a structure to perform a function, such as absorbing liquids. In another example, a fiber structure according to the invention is a nonwoven fabric. In one example, the fiber structure of the invention may include co-formed fiber structures, meltblown fiber structures, and spunbond fiber structures, as long as they contain granules. In one example, the fiber structure is a non-spunlace fiber structure. In another example, the fiber structure is a non-carded fiber structure.

[0091] In another example of the invention, the fiber structure includes a plurality of intertwined fiber elements, such as intertwined filaments, and particles dispersed between the intertwined filaments.

[0092] The fiber structure of the present invention can be homogeneous, heterogeneous, or layered. If layered, the fiber structure may contain at least two and / or at least three and / or at least four and / or at least five layers.

[0093] The fiber structure of the present invention may exhibit a basis weight of about 75 gsm to about 2000 gsm and / or about 75 gsm to about 1500 gsm and / or about 100 to about 1000 gsm. In one example, fiber elements (e.g., filaments) are present in the fiber structure of the present invention with a basis weight of about 20 gsm to about 1000 gsm and / or about 40 gsm to about 800 gsm and / or about 75 gsm to about 700 gsm and / or about 100 gsm to about 600 gsm. In one example, particles (e.g., SAP particles) are present in the fiber structure of the present invention with a basis weight of about 10 gsm to about 1000 gsm and / or about 20 gsm to about 700 gsm and / or about 40 gsm to about 600 gsm and / or about 100 gsm to about 600 gsm and / or about 150 gsm to about 400 gsm.

[0094] As used in this article, "multi-fiber element fiber structure" means a fiber structure that includes filaments and fibers, such as a co-formed fiber structure, which is a multi-fiber element fiber structure.

[0095] As used herein, “single-fiber element fiber structure” means a fiber structure that consists only of fibers or filaments (e.g., meltblown fiber structure, such as sparse fabric), rather than a mixture of fibers and filaments.

[0096] As used herein, "co-formed fiber structure" means a fiber structure comprising a mixture of filaments (such as meltblown filaments, thermoplastic filaments, such as polypropylene filaments), SAP granules, and optionally pulp fibers (such as wood pulp fibers). Filaments (such as filaments), SAP granules, and optionally pulp fibers are blended together to form a co-formed fiber structure. The co-formed fiber structure may be associated with one or more meltblown fiber structures and / or spunbond fiber structures that form a sparse fabric (or a deposited sparse fabric layer, for example, directly spun onto the surface of a simultaneously formed or pre-formed fiber structure of the present invention and / or directly spun onto a collection device before the fiber structure of the present invention is formed directly on the surface of the sparse fabric layer (via spinning)) (in one example, the sparse fabric may be present with a basis weight of greater than 0.5 gsm to about 5 gsm and / or about 1 gsm to about 4 gsm and / or about 1 gsm to about 3 gsm and / or about 1.5 gsm to about 2.5 gsm), such as on one or more surfaces of the co-formed fiber structure.

[0097] The co-molded fiber structure of the present invention can be manufactured by a suitable molding method.

[0098] As used herein, “filament” refers to the elongated particles described above, exhibiting a length greater than or equal to 5.08 cm (2 inches) and / or greater than or equal to 7.62 cm (3 inches) and / or greater than or equal to 10.16 cm (4 inches) and / or greater than or equal to 15.24 cm (6 inches).

[0099] Filaments are generally considered to be substantially continuous or substantially continuous. Filaments are relatively longer than fibers. Non-limiting examples of filaments include meltblown and / or spunbond filaments. Non-limiting examples of polymers that can be spun into filaments include natural polymers (such as starch, starch derivatives, cellulose (such as rayon and / or lyocell fiber) and cellulose derivatives, hemicellulose, hemicellulose derivatives) and synthetic polymers, including but not limited to polyvinyl alcohol filaments and / or polyvinyl alcohol derivative filaments, and thermoplastic polymer filaments such as polyesters, such as polyethylene terephthalate (PET), nylon, polyolefins such as polypropylene filaments, polyethylene filaments, polypropylene and polyethylene copolymer filaments, and biodegradable or compostable thermoplastic fibers such as polylactic acid filaments, polyhydroxyalkanoate filaments, polyesteramide filaments, and polycaprolactone filaments. Filaments can be monocomponent or multicomponent, such as bicomponent filaments. In one example, the filament is a monocomponent filament.

[0100] Filaments can be made from polymers, such as thermoplastic polymers like polyolefins (e.g., polypropylene and / or polyethylene) and / or polyesters (e.g., polyethylene terephthalate (PET)), and mixtures thereof, by spinning (e.g., by meltblowing and / or spunbonding). Filaments are generally considered to be substantially continuous or substantially continuous.

[0101] The filaments of the present invention can be spun from polymer melt compositions by suitable spinning operations (such as meltblowing and / or spunbonding), and / or they can be obtained from natural sources (such as plant sources, e.g., trees).

[0102] The filaments of this invention can be single-component and / or multi-component. For example, the filaments may include bicomponent fibers and / or filaments. Bicomponent fibers and / or filaments can be in any form, such as side-by-side, core-sheath, island-of-the-sea, etc.

[0103] Meltblowing is a method of producing filaments directly from polymers or resins, using high-speed air or another suitable force to thin the filaments before they are collected on a collecting device (such as a belt, for example a patterned belt or molded component). In the meltblowing process, a thinning force is applied in the form of high-speed air as the material (polymer) leaves the die or spinneret.

[0104] "Spunbond" is a method of producing filaments directly from a polymer by causing the polymer to leave a die or spinneret and fall a predetermined distance under the influence of fluid dynamics and gravity, and then stretching and / or drawing the polymer into filaments by applying force through high-speed air or another suitable source.

[0105] As used herein, “fiber” means, as described above, elongated particles exhibiting a length of less than 5.08 cm (2 in.) and / or less than 3.81 cm (1.5 in.) and / or less than 2.54 cm (1 in.). Pulp fibers (e.g., wood pulp fibers) typically have a length of about 0.7 mm to about 2.5 mm.

[0106] Fibers are generally considered to be substantially discontinuous. Non-limiting examples of fibers include pulp fibers (such as wood pulp fibers), as well as synthetic short fibers such as polypropylene, polyethylene, polyester, their copolymers, rayon, lyocell fibers, glass fibers, and polyvinyl alcohol fibers.

[0107] Short fibers can be produced by spinning long filament bundles and then cutting the bundles into segments smaller than 5.08 cm (2 in.) to produce fibers (i.e., short fibers).

[0108] As used herein, “pulp fiber” means fiber derived from a plant source (such as plants and / or trees). In one example of the invention, “pulp fiber” means papermaking fiber. In one example of the invention, the fiber can be a naturally occurring fiber, meaning it is obtained from a naturally occurring source (such as a plant source, like trees and / or plants), such as trichomes. Such fibers are commonly used in papermaking and are often referred to as papermaking fibers. Papermaking fibers that can be used in the present invention include cellulose fibers, commonly referred to as wood pulp fibers. Applicable wood pulps include chemical wood pulps, such as kraft pulp, sulfite pulp, and sulfate pulp, as well as mechanical wood pulps, including, for example, wood chip pulp, thermodynamic pulp, and chemically modified thermodynamic pulp. However, chemical pulps may be preferred because they impart an excellent soft touch to the fiber structure made from them. Wood pulps derived from deciduous trees (also referred to below as “hardwood”) and coniferous trees (also referred to below as “softwood”) may also be utilized. Hardwood and softwood fibers can be blended or, alternatively, deposited in layers to provide a layered fiber web. Also applicable to the invention are fibers derived from recycled paper, which may contain any or all of the aforementioned classes of fibers, as well as other non-fiber polymers such as fillers, softeners, wet strength agents, and dry strength agents, and binders for promoting primitive papermaking.

[0109] In one example, the wood pulp fibers are selected from the group consisting of: hardwood pulp fibers, softwood pulp fibers, and mixtures thereof. Hardwood pulp fibers can be selected from the group consisting of: tropical hardwood pulp fibers, northern hardwood pulp fibers, and mixtures thereof. Tropical hardwood pulp fibers can be selected from the group consisting of: eucalyptus fibers, acacia fibers, and mixtures thereof. Northern hardwood pulp fibers can be selected from the group consisting of: cedar fibers, maple fibers, and mixtures thereof.

[0110] In addition to various wood pulp fibers, other cellulose fibers (such as cotton fibers, cotton linters, rayon, lyocell fibers, fibrous fibers, seed fibers, rice straw, wheat straw, bamboo, and bagasse fibers) can also be used in this invention. Other sources of cellulose in fibrous form or capable of being spun into fibers include grass and grain sources.

[0111] As used herein, "trichome" or "trichome fiber" refers to epidermal appendages of varying shapes, structures, and / or functions on the non-seed parts of a plant. In one example, a trichome is an extension of the epidermis of a non-seed part of a plant. The extension may extend from epidermal cells. In one embodiment, the extension is a trichome fiber. The extension may be a hair-like or bristle-like extension from the plant epidermis.

[0112] The difference between trichome fibers and seed hair fibers is that they are not attached to the seed portion of a plant. For example, unlike seed hair fibers, trichome fibers are not attached to the seed or pod epidermis. Cotton, kapok, milkweed, and coconut coir are non-limiting examples of seed hair fibers.

[0113] Furthermore, trichome fibers differ from non-wood phloem and / or core fibers in that they are not attached to the phloem (also known as the bast layer) or core (also known as the xylem) of the stem of a non-wood dicotyledonous plant. Non-limiting examples of plants that have been used to produce non-wood phloem fibers and / or non-wood core fibers include kenaf, jute, flax, ramie, and hemp.

[0114] Further trichome fibers differ from fibers derived from monocotyledons, such as those derived from cereal straw (wheat, rye, barley, oats, etc.), stalks (corn, cotton, sorghum, Hesperaloe funifera, etc.), sugarcane (bamboo, bagasse, etc.), and grasses (Spanish grass, lemon, sabai, switchgrass, etc.), because these monocotyledonous fibers do not adhere to the plant's epidermis.

[0115] Furthermore, trichome fibers differ from leaf fibers in that they do not originate from within the leaf structure. Sisal and Manila hemp are sometimes released as leaf fibers.

[0116] Finally, trichome fibers differ from wood pulp fibers because wood pulp fibers do not originate from the epidermis of plants (i.e., trees). Instead, wood pulp fibers originate from the secondary xylem of the tree trunk.

[0117] As used herein, "particle" means solid material, such as powder, granules, agglomerates, capsules, microcapsules, and / or spheres. Particles can be spherical, rod-shaped, plate-shaped, tubular, square, rectangular, disc-shaped, star-shaped, or have a regular or irregular random form, such as spherical. The particles of the present invention (at least those 44 μm) can be measured using the particle size distribution testing methods described herein. For particles smaller than 44 μm, different testing methods, such as light scattering, can be used to determine particle sizes smaller than 44 μm; for example, the particle size of fragrance microcapsules is typically in the range of about 15 μm to about 44 μm and / or about 25 μm.

[0118] As used herein, particles are not fibers as defined herein; however, particles may include recycled materials derived from fibers, for example as a result of processing (e.g., recycling) fibers by grinding them into fine solids and then incorporating the fine solids into agglomerates, pellets or other particulate forms.

[0119] In one example, the particles of the present invention may include recyclable materials, compostable materials, and / or biodegradable materials.

[0120] The particles of this invention may include SAP particles, fragrance particles, odor control particles (such as zeolite, charcoal, activated carbon, β-cyclodextrin, and mixtures thereof), abrasive particles (such as silica), and thickening particles, gelling particles, such as coagulation material particles, such as chitosan, alginate, coagulants, and other naturally occurring gelling and / or thickening particles. In one example, the particles include SAP particles, particularly when the structure of this invention (e.g., a fibrous structure) will be used as an absorbent material (e.g., an absorbent core material).

[0121] As used herein, “SAP particles” are materials that absorb liquids (such as urine and / or menstrual blood) by forming a gel-like substance through which the liquid is transferred across the periphery of the material, absorbing and tightly retaining the liquid. In one example, when subjected to a centrifugal force of less than or equal to 3000 G for 10 to 15 minutes, SAP particles retain more than 5 times their weight in deionized water. In contrast, typical capillary absorbents retain about 1 times their weight in deionized water under similar conditions. Non-limiting examples of SAP particles include cross-linked polyacrylic acid and / or cross-linked carboxymethyl cellulose.

[0122] SAP particles comprise synthetic crosslinked polymeric materials that can absorb and retain tens or even hundreds of times their own weight in aqueous fluids via hydrogen bonding and / or chemisorption into their polymer chains (chemi-storage). SAP particles are now typically (though not exclusively) produced by polymerizing acrylic acid with sodium hydroxide in the presence of an initiator to form sodium polyacrylate (sometimes referred to as sodium polyacrylate). Other non-limiting examples of materials that can be used to manufacture SAP particles include polyacrylamide copolymers, ethylene maleic anhydride copolymers, crosslinked carboxymethyl cellulose, polyvinyl alcohol copolymers, crosslinked polyethylene oxide, and starch-grafted copolymers of polyacrylonitrile with biological blood binding and / or coagulation material granules (such as alginate). Current sources of SAP particles suitable for the methods and structures described herein (e.g., absorbent materials) include, but are not limited to, Nippon Shokubai (Osaka, Japan), BASF (Ludwigshafen, Germany (on the Rhine)), and Evonik Industries (Essen, North Rhine-Westphalia, Germany).

[0123] In one example, the SAP particles comprise highly cross-linked sodium polyacrylate, which allows the SAP particles to absorb and retain fluids such as urine and / or menstrual flow even under moderate pressure. Such SAP particles are suitable for use in absorbent materials that can be included in, for example, diapers, feminine hygiene products, and / or adult incontinence products.

[0124] In another example, SAP particles comprise lightly cross-linked sodium polyacrylate, which causes the SAP particles to absorb liquids (such as urine and / or menstrual blood) but release them under moderate pressure. Such SAP particles are suitable, for example, for absorbent materials that can be included in floor cleaning mats.

[0125] In one example, SAP particles may include recyclable materials, compostable materials, and / or biodegradable materials.

[0126] In one example, the first particle (e.g., SAP particle) may include water-insoluble particles.

[0127] In one example, the first particle (e.g., SAP particle) may include water-swellable particles.

[0128] Smaller SAP particles (e.g., SAP particles with an average particle size of less than 300 μm and / or less than 200 μm and / or less than 100 μm) absorb fluids (e.g., urine and / or menstrual blood) more quickly than larger SAP particles (e.g., SAP particles with an average particle size of greater than 400 μm and / or greater than 500 μm and / or greater than 600 μm).

[0129] The Stokes number, or Stk, is mathematically defined as...

[0130]

[0131] "Particle time constant" or t p In mathematics it is defined as

[0132]

[0133] Where ρ d It is the particle ("solid additive") density, d d It is the geometric mean of the major and minor axes of the particle, and μ g It is the viscosity of a fluid (such as air) that carries particles.

[0134] "Fluid time constant" or t o In mathematics it is defined as

[0135]

[0136] Among them l o It is the length of interest in the analysis region, and v o The overall velocity in the analysis area is as used in this paper; "basic weight" is the weight of the sample per unit area, expressed in lbs / 3000ft. 2 or g / m 2 Reports are made in units of (gsm) and measurements are performed according to the basis weight test method described herein.

[0137] As used in this article, "longitudinal" or "MD" means the direction parallel to the fiber structure flow through fiber structure manufacturing machines and / or toilet paper product manufacturing equipment.

[0138] As used in this article, "horizontal" or "CD" means a direction that is parallel to the width of fiber structure manufacturing machines and / or toilet paper product manufacturing equipment and perpendicular to the longitudinal direction.

[0139] As used in this article, “different” in relation to particles means that two or more particles exhibit different properties, such as different size, shape, density, mass, Stokes number and / or composition.

[0140] As used in this article, “lamellae” refers to a single, integral fiber structure.

[0141] As used herein, "multiple layers" means two or more individual monolithic fiber structures arranged in a substantially adjacent, face-to-face relationship to form a multilayer toilet paper product. It is also considered that individual monolithic fiber structures can, for example, effectively form multilayer toilet paper products by folding themselves.

[0142] “X” or “Y” or “xy” and “Z” or “z” denote a conventional Cartesian coordinate system, where mutually perpendicular coordinates “X” and “Y” define a reference to the XY(xy) plane, and “Z” defines orthogonality to the XY plane. “Z-direction” refers to any direction perpendicular to the XY plane. Similarly, the term “Z-dimension” means a dimension, distance, or parameter measured parallel to the Z-direction. When an element (such as a molded component) is bent or otherwise deplanarized, the XY plane follows the configuration of the element.

[0143] As used in this article, “inelastic” means a material that does not exhibit elastic properties and / or elasticity and / or is an elastomer.

[0144] As used in this article, “particle size distribution span” means (D90–D10) / D50 × 100%.

[0145] As used herein, the articles “a” and “an” when used herein, such as “an anionic surfactant” or “a fiber”, are understood to refer to one or more of the materials protected by or described in the claims.

[0146] Unless otherwise specified, all percentages and ratios are by weight. Unless otherwise specified, all percentages and ratios are based on the total composition.

[0147] Unless otherwise stated, all component or composition levels refer to the level of the active substance in that component or composition and do not include impurities that may be present in commercially available sources, such as residual solvents or byproducts.

[0148] Methods for manufacturing fibrous structures

[0149] In such Figure 3A In one example shown, the inventive method 50 of the present invention is a method for controlling the distribution of particles 20 within a structure 26 (e.g., a fibrous structure, such as an absorbent material, such as an absorbent core material). In one example, the fibrous structure produced by the method of the present invention exhibits properties suitable for the method of the present invention and contains components suitable for the method of the present invention. Method 50 includes the steps of: blending a particle flow 52 (including a fluid flow of multiple particles 20) (indicated by arrows) containing a plurality of particles 20 with a filament flow 54 (including a fluid flow of multiple filaments 24) (indicated by arrows) containing a plurality of filaments 24 to form a composite fluid flow 56 (composite flow 56), and collecting the composite flow 56 on a collecting device 25 (e.g., a belt) such that the structure 26, such as a fibrous structure, such as an absorbent material, such as an absorbent core material, exhibits a non-random arrangement of the plurality of particles 20 in the structure.

[0150] Multiple particles 20 can be introduced into method 50 via a particle stream 52 originating from particle source 58 (e.g., a hopper).

[0151] Multiple filaments 24 can be introduced into method 50 via a filament stream 54 originating from filament source 30 (e.g., a die, such as a meltblown die and / or a spunbond die, such as a knife-edge die or a multi-row capillary die, examples of which are available from Biax-Fiberfilm, Greenville, Wisconsin).

[0152] The particle flow 52 may intersect the filament flow 54 at an angle α during method 50. The angle α may range from about 5° to about 130° and / or from about 10° to about 110° and / or from about 20° to about 90° and / or from about 40° to about 90°.

[0153] In one example, the particle stream 52 and the filament stream 54 intersect and blend in a closed and / or substantially closed environment (e.g., a casing 60, such as a co-forming box), such that the filament source 30 and optionally the particle source 58 are connected to and in fluid communication with the casing 60, as in, for example Figure 3A As shown in the image.

[0154] In addition, such as Figure 3A As shown, method 50 can be arranged as a single, one-sided injection of multiple particles 20, which produces structure 26, such as a fibrous structure, like an absorbent material, such as an absorbent core material, which exhibits the following characteristics: Figure 3B and Figure 3C The particle size distribution of the particles 20 shown is a non-random arrangement (controlled or designed distribution). This non-random arrangement of particle size results in a structure, such as a fibrous structure, or an absorbent material like an absorbent core material, exhibiting the following continuous gradient: relatively large particles (e.g., particles with a relatively high Stokes number) on and / or near one side (bottom B side) and relatively small particles (e.g., particles with a relatively low Stokes number) on and / or near the opposite side (top T side).

[0155] In such Figure 4A In another example shown, the inventive method 50 of the present invention is a method for controlling the distribution of particles 20 within a structure 26 (e.g., a fibrous structure, such as an absorbent material, such as an absorbent core material). Method 50 includes the steps of: blending a particle stream 52 (indicated by arrows) comprising a plurality of particles 20 with a filament stream 54 (indicated by arrows) comprising a plurality of filaments 24 to form a composite stream 56, and collecting the composite stream 56 on a collecting device 25 (e.g., a belt) such that the structure 26, such as a fibrous structure, such as an absorbent material, such as an absorbent core material, exhibits a non-random arrangement of the plurality of particles 20 within the structure.

[0156] Multiple particles 20 can be introduced into method 50 via a particle stream 52 originating from particle source 58 (e.g., a hopper).

[0157] Multiple filaments 24 can be introduced into method 50 via a filament stream 54 originating from filament source 30 (e.g., a die, such as a meltblown die and / or a spunbond die, such as a knife-edge die or a multi-row capillary die, examples of which are available from Biax-Fiberfilm, Greenville, Wisconsin).

[0158] The particle flow 52 may intersect the filament flow 54 at an angle α during method 50. The angle α may range from about 5° to about 130° and / or from about 10° to about 110° and / or from about 20° to about 90° and / or from about 40° to about 90°.

[0159] In one example, the particle stream 52 and the filament stream 54 intersect and blend in a closed environment (e.g., a casing 60, such as a co-forming box), such that the filament source 30 and optionally the particle source 58 are connected to and in fluid communication with the casing 60, as in, for example Figure 4A As shown in the image.

[0160] In addition, such as Figure 4A As shown, method 50 can be arranged as a single-sided, single-injection of multiple particles 20, which produces a structure, such as a fibrous structure, like an absorbent material, such as an absorbent core material, exhibiting the following characteristics: Figure 4B and Figure 4C The non-random arrangement (controlled or designed distribution) particle size distribution is shown. This non-random arrangement produces a structure, such as a fibrous structure, or an absorbent material like an absorbent core material, that exhibits the following continuous gradient: relatively large particles (e.g., particles with a relatively high Stokes number) on and / or near one side (top T side) and relatively small particles (e.g., particles with a relatively low Stokes number) on and / or near the opposite side (bottom B side).

[0161] In another example, method 50 can be arranged as a single-sided, dual-injection (not shown) of multiple particles 20, such that two different particle streams 52 (a first particle stream and a second particle stream) that may include different particles 20 are introduced into a filament stream 54. Intersections of the different particle streams 52 with the filament stream 54 can occur at the same or different points along the filament stream 54. In yet another example, method 50 can be arranged as a single-sided, multiple-injection of multiple particles 20, such that multiple (three or more) different particle streams 52 that may include different particles are introduced into the filament stream 54. Intersections of the different particle streams 52 with the filament stream 54 can occur at the same and / or different points along the filament stream 54. The non-random arrangement (controlled distribution or designed distribution) of the single-sided, dual-injection and / or single-sided, multiple-injection methods 50 appears similar to Figure 3B and Figure 3C or Figure 4B and Figure 4C .

[0162] In yet another example of the invention, such as Figure 5A As shown, method 50 includes a first warp axis 62, which includes as described above regarding... Figure 4A The filament source 30 and particle source 58 are described. Similar to the above regarding... Figure 4A The described method, through the operation of the first axis 62, produces a resulting structure 26 comprising a non-random arrangement of particles 20, such as a continuous gradient of particle size within the resulting structure 26. Figure 5A As shown, the resulting structure 26 includes a continuous gradient of particle size, with larger particles closer to the top T side and smaller particles closer to the bottom B side. After forming the resulting structure 26, the top T side surface of the resulting structure 26 is then brought into contact with a second plurality of filaments 24 spun from a second filament source 30 from a second warp beam 64, thereby producing a layered structure 66, such as a fibrous structure, like an absorbent material, such as an absorbent core material, such as... Figure 5B As shown. A second plurality of filaments 24 are spun directly onto the top T-side surface of the resulting structure 26 to form a layer of filaments 24, which can serve as a loosely woven layer 68 to help retain the particles 20 within the resulting structure 26. Figure 5B In this case, the average fiber diameter of the filaments 24 in the resulting structure 26 and the filaments 24 in the loose fabric layer 68 is the same or substantially the same.

[0163] Figure 5C and Figure 5D The layered structure 66 shown can also be... Figure 5A Method 50 is formed by producing filaments 24 with different average fiber diameters from at least two different warp axes. Figure 5CAn example of a layered structure 66 is shown, in which the filaments 24 produced by the first warp beam 62 exhibit a smaller average fiber diameter than the filaments 24 produced by the second warp beam 64, which produces a loosely sparse fabric layer 68. Figure 5C The particles 20 in the layered structure 66 exist in the resulting structure 26 in a non-random arrangement (e.g., a continuous gradient of particle size). Figure 5D Another example of a layered structure 66 is shown, in which the filaments 24 produced by the first warp beam 62 exhibit a larger average fiber diameter than the filaments 24 produced by the second warp beam 64, which produces a loosely sparse fabric layer 68. Figure 5D The particles 20 in the layered structure 66 exist in the resulting structure 26 in a non-random arrangement (e.g., a continuous gradient of particle size).

[0164] In yet another example of the invention, such as Figure 6A As shown, method 50 includes a first warp axis 62, which includes as described above regarding... Figure 3A The described filament source 30 and particle source 58. (This is related to the above regarding...) Figure 3A As described, the operation of the first meridian 62 produces the resulting structure 26, which includes a non-random arrangement of particles 20, such as a continuous gradient of particle size within the resulting structure 26. Figure 6A As shown, the resulting structure 26 includes a continuous gradient of particle size, with larger particles closer to the bottom B side and smaller particles closer to the top T side. After forming the resulting structure 26, the top T side surface of the resulting structure 26 is then brought into contact with a second plurality of filaments 24 spun from a second filament source 30 from a second warp beam 64, thereby producing a layered structure 66, such as a fibrous structure, as in absorbent materials, such as absorbent core materials, such as... Figure 6B As shown. A second plurality of filaments 24 are spun directly onto the top T-side surface of the resulting structure 26 to form a layer of filaments 24, which can serve as a loosely woven layer 68 to help retain the particles 20 within the resulting structure 26. Figure 6B In this case, the average fiber diameter of the filaments 24 in the resulting structure 26 and the filaments 24 in the loose fabric layer 68 is the same or substantially the same.

[0165] Figure 6C and Figure 6D The layered structure 66 shown can also be... Figure 6A Method 50 is formed by producing filaments 24 with different average fiber diameters from at least two different warp axes. Figure 6C An example of a layered structure 66 is shown, in which the filaments 24 produced by the first warp beam 62 exhibit a smaller average fiber diameter than the filaments 24 produced by the second warp beam 64, which produces a loosely sparse fabric layer 68. Figure 6CThe particles 20 in the layered structure 66 exist in the resulting structure 26 in a non-random arrangement (e.g., a continuous gradient of particle size). Figure 6D Another example of a layered structure 66 is shown, in which the filaments 24 produced by the first warp beam 62 exhibit a larger average fiber diameter than the filaments 24 produced by the second warp beam 64, which produces a loosely sparse fabric layer 68. Figure 6D The particles 20 in the layered structure 66 exist in the resulting structure 26 in a non-random arrangement (e.g., a continuous gradient of particle size).

[0166] In such Figure 7A In another example shown, method 50 can be arranged as a bilateral, dual injection of multiple particles 20, wherein a first particle stream 52 is introduced on one side of the casing 60 (e.g., the upstream side of the casing 60 and / or method 50) and a second particle stream 52 is introduced on the other side of the casing 60 (e.g., the downstream side of the casing 60 and / or method 50). Figure 7A The method 50 shown produces a structure, such as a fibrous structure, like an absorbent material, such as an absorbent core material, which exhibits the following characteristics: Figure 7B and Figure 7C The non-random arrangement (controlled or designed distribution) particle size distribution is shown. This non-random arrangement produces a structure, such as a fibrous structure, or an absorbent material like an absorbent core material, exhibiting the following continuous gradient: relatively large particles (e.g., particles with relatively high Stokes numbers) on and / or near one side (e.g., the top T side) and relatively smaller particles (e.g., particles with relatively low Stokes numbers) reaching and passing through the center on and / or near the opposite side (e.g., the bottom B side), followed by relatively large particles (e.g., particles with relatively high Stokes numbers) that may be the same, similar, or different from the large particles on and / or near the top T side. In another example, method 50 can be arranged as a bilateral, dual injection of multiple particles 20, such that two different particle streams 52, which may include different particles, are introduced into a filament stream 54. Intersections of the different particle streams 52 with the filament stream 54 can occur at the same or different points along the filament stream 54. In yet another example, method 50 can be arranged as bilateral, multiple injections of multiple particles 20, such that multiple (three or more) different particle streams 52, which may include different particles, are introduced into the filament stream 54. Intersections of the different particle streams 52 with the filament stream 54 can occur at the same and / or different points along the filament stream 54.

[0167] In addition to the controlled distribution of particles provided by the method of the present invention, such as Figure 8AThe method 50 of the present invention shown may optionally include adding a stream of non-particulate solid additives 70 comprising a variety of non-particulate solid additives 72 (e.g., fibers, such as pulp fibers, e.g., wood pulp fibers) to a filament stream 54 and / or a composite stream 56. In one example, the non-particulate solid additives 72 (e.g., fibers) remain separated from the particles 20 before being introduced into the shell 60 and / or before being blended with the filaments 24. Similarly, the particles 20 remain separated from the non-solid additive particles 72 (e.g., fibers) before being introduced into the shell 60 and / or before being blended with the filaments 24.

[0168] like Figure 8A As shown, an example of method 50 of the present invention includes the following steps: a) blending a filament stream 54 comprising multiple filaments 24 with a non-particulate solid additive stream 70 comprising multiple non-particulate solid additives 72 (e.g., fibers, such as pulp fibers, such as wood pulp fibers) to form a mixed stream 74 comprising multiple filaments 24 and multiple non-particulate solid additives 72; b) blending a particle stream 52 comprising multiple particles 20 as described above with the mixed stream 74 to form a composite material stream 56, and collecting the composite material stream 56 on a collecting device 25 (e.g., a belt) to form a structure 26, such as a fibrous structure, such as an absorbent material, such as an absorbent core material, exhibiting a non-random arrangement of multiple particles 20 in the structure. Such a structure 26 comprises multiple filaments 24, multiple non-particulate solid additives 72, and multiple particles 20. The resulting structure 26 comprises a non-random arrangement of particles 20 in the resulting structure 26.

[0169] In such Figure 8A In the method 50 of the present invention shown, method 50 includes the following steps: blending a stream of non-particulate solid additives 70 (indicated by arrows) comprising a plurality of non-particulate solid additives 72 with a stream of filaments 54 (indicated by arrows) comprising a plurality of filaments 24 to form a mixed stream 74; blending a stream of particles 52 (indicated by arrows) comprising a plurality of particles 20 with the mixed stream 74 comprising a plurality of filaments 24 and a plurality of non-particulate solid additives 72 to form a composite material stream 56 comprising a plurality of particles 20, a plurality of non-particulate solid additives 72 and a plurality of filaments 24; and collecting the composite material stream 56 on a collecting device 25 (e.g., a belt) such that a structure 26 is formed, such as a fibrous structure, like an absorbent material, such as an absorbent core material, exhibiting a non-random arrangement of the plurality of particles 20 in the structure.

[0170] Multiple particles 20 can be introduced into method 50 via a particle stream 52 originating from particle source 58 (e.g., a hopper).

[0171] Multiple filaments 24 can be introduced into method 50 via a filament stream 54 originating from filament source 30 (e.g., a die, such as a meltblown die and / or a spunbond die, such as a knife-edge die or a multi-row capillary die, examples of which are available from Biax-Fiberfilm, Greenville, Wisconsin).

[0172] Non-particulate solids additive 72 may be introduced into method 50 from a non-particulate solids additive source (not shown), such as a hopper and / or crusher, and / or sorting roller, and / or hammer mill, if the non-particulate solids additive 72 in one or more of the latter three examples contains fibers, such as pulp fibers, for example, wood pulp fibers.

[0173] The particle flow 52 may intersect the filament flow 54 at an angle α during method 50. The angle α may range from about 5° to about 130° and / or from about 10° to about 110° and / or from about 20° to about 90° and / or from about 40° to about 90°.

[0174] The non-particulate solid additive stream 70 may intersect the filament stream 54 at an angle β during method 50. The angle β may range from about 5° to about 130° and / or from about 10° to about 110° and / or from about 20° to about 90° and / or from about 40° to about 90°.

[0175] In one example, the non-particulate solid additive stream 70, the filament stream 54, the particle stream 52, and the filament stream 54 intersect and blend in a closed environment (e.g., a casing 60, such as a co-forming box), such that the filament source 30 and the optional particle source 58 are connected to and in fluid communication with the casing 60, as in, for example... Figure 3A As shown in the image.

[0176] In addition, such as Figure 8A As shown, method 50 can be arranged as a single, one-sided injection of multiple particles 20, which produces structure 26, such as a fibrous structure, like an absorbent material, such as an absorbent core material, which exhibits the following characteristics: Figure 8B and Figure 8C The particle size distribution of the particles 20 shown is a non-random arrangement (controlled or designed distribution). The uncontrolled distribution of the non-particulate solid additive 72 (e.g., fibers, such as pulp fibers, e.g., wood pulp fibers) results in a random and / or uncontrolled arrangement of the non-particulate solid additive 72 in structure 26. The non-random arrangement of particle size distribution produces a structure, such as a fibrous structure, such as an absorbent material, such as an absorbent core material, that exhibits the following continuous gradient: relatively large particles (e.g., particles with a relatively high Stokes number) on and / or near one side (bottom B side) and relatively small particles (e.g., particles with a relatively low Stokes number) on and / or near the opposite side (top T side), such as... Figure 8BAs shown, if the MD direction is opposite to the indicated direction, or alternatively, if the particle flow 52 is introduced on the opposite side of the casing 60, this continuous gradient will be... Figure 8A The settings shown are generated. Figure 8C The resulting structure 26 shown will be derived from, as Figure 8A The method 50 shown produces a structure 26 (such as a fibrous structure, or an absorbent material, such as an absorbent core material) exhibiting the following continuous gradient: relatively large particles (e.g., particles with a relatively high Stokes number) on and / or near one side (top T side) and relatively small particles (e.g., particles with a relatively low Stokes number) on and / or near the opposite side (bottom B side), such as... Figure 8C As shown.

[0177] Figure 8B The structure 26 shown may also include modifications Figure 6A The loosely woven layer 68 obtained by the method shown is achieved by replacing the first warp beam 62 with Figure 8A The image shown has been modified to produce Figure 8B This is achieved through the configuration of structure 26 shown. The resulting layered structure 66 is... Figure 8D As shown in the image.

[0178] The layered structure 66 may also include filaments 24 in the structure 26 layers and the loosely woven layer 68, these filaments exhibiting different average fiber diameters, as described above. For example, Figure 8E The diagram shows filaments 24 in the loosely woven layer 68, which exhibit a smaller average fiber diameter compared to the filaments 24 in the structure layer 26. Similarly, Figure 8F The filaments 24 in the loosely woven layer 68 are shown, which exhibit a larger average fiber diameter compared to the filaments 24 in the structure layer 26.

[0179] Figure 8C The structure 26 shown may also include modifications Figure 5A The loosely woven layer 68 obtained by the method shown is achieved by replacing the first warp beam 62 with Figure 8A This is achieved through the setup shown. The resulting layered structure 66 is... Figure 8G As shown in the image.

[0180] The layered structure 66 may also include filaments 24 in the structure 26 layers and the loosely woven layer 68, these filaments exhibiting different average fiber diameters, as described above. For example, Figure 8H The diagram shows filaments 24 in the loosely woven layer 68, which exhibit a smaller average fiber diameter compared to the filaments 24 in the structure layer 26. Similarly, Figure 8I The filaments 24 in the loosely woven layer 68 are shown, which exhibit a larger average fiber diameter compared to the filaments 24 in the structure layer 26.

[0181] As described above, the average fiber diameter of the filaments 24 produced by different filament sources 30 (e.g., within the first warp beam 62 and the second warp beam 64) can be achieved, for example, by utilizing drawing air at different speeds and / or polymer melts exiting different filament sources 30 at different fluxes.

[0182] although Figure 5A and Figure 6A The method 50 shown only illustrates an example of two warp beams (first warp beam 62 and second warp beam 64) for manufacturing two layered structures 66, but one or more additional warp beams (warp beams similar to the first warp beam 62 or similar to the second warp beam 64 and / or both) can be added to method 50. For example, if method 50 includes an additional warp beam similar to the second warp beam 64 positioned upstream (before) the first warp beam 62, a first layer of multiple filaments 24 is spun onto the collecting device 25, thereby producing a first layer, such as a first sparse fabric layer. The composite material flow 56 from the first warp beam 62 is then spun directly onto the first sparse fabric layer, and then a second sparse fabric layer is spun directly from the second warp beam 64 onto the layer formed by the composite material flow 56 from the first warp beam 62, thereby producing a three-layer structure in which structure 26 is sandwiched between two sparse fabric layers 68.

[0183] In one example, the angle α between the particle flow 52 and the filament flow 54 and / or the mixed flow 74 (depending on the implementation of the method 50 being operated) and / or the velocity of the fluid (such as air) carrying the particles 20 in the particle flow 52 can be varied and / or adjusted to control the distribution of the particles 20 within the method 50 and ultimately within the resulting structure 26 (e.g., a fibrous structure, such as an absorbent material, such as an absorbent core material), such that a non-random arrangement of multiple particles 20 is produced within the structure.

[0184] As long as the structure of the present invention is produced, one or more particle streams 52 can be introduced into the filament stream 54 at any location within the casing 60 and / or process. For example, a particle stream 52 can be introduced into the filament stream 54 upstream of the casing 60 and / or process (e.g., substantially parallel to MD). Similarly, a particle stream 52 can be introduced into the filament stream 54 downstream of the casing 60 and / or process (e.g., substantially parallel to MD).

[0185] In one example, the step of mixing a first fluid flow comprising multiple fiber elements with a second fluid flow comprising multiple first particles occurs at two or more locations on the upstream side of the first fluid flow.

[0186] In another example, the step of mixing a first fluid flow comprising multiple fiber elements with a second fluid flow comprising multiple first particles occurs at two or more locations on the downstream side of the first fluid flow.

[0187] In one example, the method further includes the step of mixing a third fluid flow comprising multiple fibers with a first fluid flow comprising multiple fiber elements. In one example, the step of mixing the third fluid flow comprising multiple fibers with the first fluid flow comprising multiple fiber elements includes blending the multiple fibers (e.g., pulp fibers) of the third fluid flow with the multiple fiber elements of the first fluid flow.

[0188] In one example, the method further includes the step of mixing one or more additional fluid flows, the additional fluid flows comprising a plurality of additional particles that are different from the plurality of first particles. In one example, the plurality of additional particles comprises a composition different from that of the first particles. In one example, at least one of the plurality of first particles exhibits a first Stokes number different from that of at least one of the additional particles.

[0189] In one example, the method further includes the step of mixing a fourth fluid flow comprising a plurality of second particles with at least one of a first fluid flow and a second fluid flow. In one example, the plurality of second particles may be different from the plurality of first particles. In one example, the plurality of second particles may be the same as the plurality of first particles. In one example, the second fluid flow and the fourth fluid flow mix with the first fluid flow from different sides of the first fluid flow. In one example, the second fluid flow mixes with the first fluid flow from a downstream side of the first fluid flow, and the fourth fluid flow mixes with the first fluid flow from an upstream side of the first fluid flow. In one example, the second fluid flow mixes with the first fluid flow from a driving side of the first fluid flow, and the fourth fluid flow mixes with the first fluid flow from a downstream side of the first fluid flow. In one example, the second fluid flow mixes with the first fluid flow from either an upstream or downstream side of the first fluid flow, and the fourth fluid flow mixes with the first fluid flow from both an upstream and downstream side of the first fluid flow.

[0190] In one example, the second fluid flow and the fourth fluid flow mix with the first fluid flow from the same side of the first fluid flow.

[0191] In another example, the method further includes the step of collecting a fluid flow of the composite material on a collection device, thereby forming a fibrous structure exhibiting a non-random arrangement of a plurality of first particles in the fibrous structure. In one example, the non-random arrangement of the plurality of first particles in the fibrous structure is based on particle properties selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixing properties. In one example, the particle property is size, for example, the non-random arrangement of the plurality of first particles in the fibrous structure includes: a first group of particles, which includes at least a majority of larger-sized particles present in a first portion of the thickness in the z-direction of the fibrous structure; and a second group of particles, which includes at least a majority of smaller-sized particles present in a second portion of the thickness in the z-direction of the fibrous structure, which is different from the first portion, and / or the first portion of the thickness in the z-direction of the fibrous structure is closer to one side of the fibrous structure than the second portion, and / or the second portion of the thickness in the z-direction of the fibrous structure is closer to one side of the fibrous structure than the first portion, and / or the first portion of the thickness in the z-direction of the fibrous structure is closer to one side of the fibrous structure and the second portion of the thickness in the z-direction of the fibrous structure is closer to the opposite side of the fibrous structure.

[0192] In one example, the plurality of first particles in the fiber structure are based on the particle characteristic Stokes number. For example, the non-random arrangement of the plurality of first particles in the fiber structure includes: a first group of particles, which includes at least a majority of particles with larger Stokes numbers present in a first portion of the thickness in the z-direction of the fiber structure; and a second group of particles, which includes at least a majority of particles with smaller Stokes numbers present in a second portion of the thickness in the z-direction of the fiber structure, which is different from the first portion, such that the first portion of the thickness in the z-direction of the fiber structure is closer to one side of the fiber structure than the second portion, and / or the second portion of the thickness in the z-direction of the fiber structure is closer to one side of the fiber structure than the first portion, and / or the first portion of the thickness in the z-direction of the fiber structure is closer to one side of the fiber structure and the second portion of the thickness in the z-direction of the fiber structure is closer to the opposite side of the fiber structure.

[0193] In one example, the non-random arrangement of multiple first particles in the fiber structure results in the multiple first particles existing in the fiber structure as a z-direction gradient based on particle properties selected from a group consisting of: size, shape, mass, density, Stokes number, and their mixed properties, for example, particle property being size. In one example, the z-direction gradient is a continuous gradient, for example, a continuous gradient existing throughout the entire z-direction thickness of the fiber structure. In one example, the z-direction gradient exists in a form smaller than the entire z-direction thickness of the fiber structure. In one example, the particle property of the multiple first particles is the Stokes number, for example, the z-direction gradient is a continuous gradient, for example, where the continuous gradient exists throughout the entire z-direction thickness of the fiber structure. In one example, the z-direction gradient exists in a form smaller than the entire z-direction thickness of the fiber structure.

[0194] In one example, the fiber structure includes a uniform z-direction concentration of the first particles.

[0195] In one example, the fiber structure includes a non-uniform z-direction concentration of the first particle.

[0196] In one example, the fiber structure comprises two or more distinct z-direction concentration layers of the first particle.

[0197] In one example, based on particle properties selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixed characteristics, the fiber structure comprises two or more distinct xy-plane regions of the first particle. In another example, the two or more xy-plane regions of the first particle comprise two or more stripes of the first particle. In yet another example, based on particle properties selected from the group consisting of: at least one stripe of the two or more stripes of the first particle exhibits a z-direction gradient of the first particle within at least one stripe of the first particle: size, shape, mass, density, Stokes number, and their mixed characteristics.

[0198] In one example, the fiber structure comprises two or more distinct xy-plane regions of the first particle, based on different concentration levels of the first particle.

[0199] In one example, the fiber structure includes a first group of multiple first particles concentrated near a first third of the thickness of the fiber structure in the z-direction and a second group of multiple first particles concentrated near a relative third of the thickness of the fiber structure in the z-direction. For example, the maximum particle size exhibited by the first group of multiple first particles is at least twice the maximum particle size of the second group of multiple first particles, such that the maximum particle size exhibited by the first group of multiple first particles is at least three times the maximum particle size of the second group of multiple first particles.

[0200] In one example, the method further includes the step of depositing a loose fabric layer on at least one surface of the fiber structure, wherein the loose fabric layer comprises a plurality of loose fabric filaments, such as water-insoluble filaments and / or thermoplastic filaments, such as thermoplastic filaments comprising, for example, polyolefins selected from the group consisting of: propylene, ethylene, copolymers thereof and mixtures thereof.

[0201] In one example, the method includes two or more steps of mixing a first fluid flow comprising a plurality of fiber elements and a second fluid flow comprising a plurality of first particles.

[0202] In one example, the collection device of the method comprises a nonwoven fiber web material.

[0203] In one example, multiple first particles exist in the fiber structure with a basis weight of approximately 10 gsm to approximately 1000 gsm.

[0204] In one example, a method for manufacturing a fibrous structure containing particles includes the following steps:

[0205] a. Adding a plurality of first particles to a first stream of a first filament having a first average diameter to form a first composite material stream;

[0206] b. Collect the first composite material stream onto a collection device to form the first layer of the fiber structure;

[0207] c. Adding a plurality of second particles to a second filament having a second average diameter different from the first average diameter to form a second composite material flow;

[0208] d. The second composite material flow is directly collected onto the first layer of the fiber structure to form a layered fiber structure comprising the first layer and the second layer formed by the second composite material flow.

[0209] In one example, the first average diameter is smaller than the second average diameter, for example, where the first average diameter is less than 6 μm and / or about 2 μm to about 5 μm.

[0210] In one example, the second average diameter is 6 μm or greater, for example, where the second average diameter is about 6 μm to about 10 μm.

[0211] In one example, the first stream of the first filament also includes multiple first fibers, such as pulp fibers, like wood pulp fibers.

[0212] In one example, a first stream of multiple first fibers is blended with a first filament, for example, wherein the blending of multiple fibers with the filament stream occurs simultaneously with the addition of multiple first particles to the first stream of the first filament, and / or wherein the blending of multiple first fibers with the first filament in the first stream occurs before the addition of multiple first particles to the first stream of the first filament.

[0213] In one example, the step of adding multiple first particles to the first flow of the first filament occurs within the cladding.

[0214] In one example, the step of adding multiple first particles to the first flow of a first filament occurs within a closed environment.

[0215] In one example, the step of adding multiple first particles to the first flow of the first filament occurs at an addition angle of approximately 30° to approximately 120°.

[0216] In one example, a plurality of first particles are uniformly distributed in the layered fiber structure in a non-random arrangement, for example, where the non-random arrangement is based on the layered distribution of one or more different particle properties within the fiber structure.

[0217] The controlled distribution of particles in this invention allows particles 20 to be placed within the resulting structure (e.g., a fibrous structure, such as an absorbent material, such as an absorbent core material) as needed in the x, y, and z directions (e.g., in different regions and / or zones and / or stripes).

[0218] Furthermore, the controlled distribution of particles in this invention allows particles 20 to be placed within the resulting structure (e.g., a fibrous structure, such as an absorbent material, such as an absorbent core material) in the x, y, and z directions as needed, to create different regions and / or zones and / or stripes based on particle concentration (meaning amount and / or level, such as mass and / or weight percentage per unit volume), particle type, particle size, particle density, particle mass, particle Stokes number, and / or particle shape.

[0219] Figure 9 This is a schematic diagram illustrating an example of method 50 of the present invention. The relevant table 1 below defines... Figure 9 Components. For example... Figure 9 As shown, the particles (not shown) from the particle stream 52 from the particle source (not shown) can be introduced via the nozzle 75 and / or the filament stream 54 and / or the mixed stream 74 in a non-limiting manner, such that the angle α can exhibit the aforementioned angle range.

[0220]

[0221]

[0222] Table 1

[0223] Incorporating particles into a flow of fibrous elements (e.g., a filament flow) to create a composite fluid flow comprising both fibrous elements (e.g., filaments) and particles, and ultimately producing a fibrous structure upon collection of the composite fluid flow on a collection device, is no easy task, especially when the particles are introduced via a separate fluid flow (e.g., an airflow) comprising multiple particles. Factors that may affect this incorporation may include one or more of the following: 1) the mass flow rate, velocity, and angle of all other airflows (e.g., the fluid flow comprising fibrous elements), as the fluid flow comprising fibrous elements may require different properties and conditions than the fluid flow comprising particles; 2) the Stokes number of the particles, which relates to physical properties such as particle density, particle shape, and particle size, and will determine the trajectory of each particle based on the angle and velocity at which it enters the mixing region; and 3) the desired distribution of the particles in the x, y, and z dimensions of the resulting fibrous structure, relating to particle strength (e.g., concentration, such as the mass ratio to other materials at a given location) and particle size (e.g., non-uniform particle size distribution).

[0224] Some of the complexities in achieving the desired particle distribution are... Figure 10 The diagram illustrates a combination of a fluid flow (e.g., an airflow) for delivering fibrous elements (e.g., filaments 24 from a filament source 30 such as a die) and a particulate fluid flow 52 (particulate flow 52) comprising particles 20. The filament flow at the particle junction (particulate fluid flow 52 mixed with filaments 24) exhibits a strong velocity profile, with the highest velocity at the center of the mixing region and lower velocities upstream and downstream of the center. The actual trajectory of each particle 20 injected by nozzle 75 is a function of its Stokes number. The angular acceleration of each particle 20 (i.e., the magnitude by which the trajectory bends toward the collection device) is then a function of the local air velocity. This results in a complex travel path for the particles 20. Specifically, particles 20 with larger Stokes numbers may accelerate toward the collection device in the upper half of the mixing region. However, if the velocity in the z-direction is higher than that of the surrounding air on the downstream side of the casing 60, it will decelerate in the z-direction, creating an inflection point. Furthermore, physical constraints (such as the presence of the sidewalls of the encapsulation mixing region 60) can subsequently cause larger particles to bounce off the downstream sidewalls of the encapsulation 60, thereby causing larger particles to be further deposited on the upstream side.

[0225] like Figure 11 As shown, the method of the present invention includes the following steps: mixing a first fluid flow comprising a plurality of fiber elements (e.g., a filament flow 54 comprising a plurality of filaments 24) with a second fluid flow comprising a plurality of first particles 20 (e.g., a particle flow 52), such that a composite fluid flow 56 exhibiting a non-random arrangement of the plurality of first particles 20 is formed. Figure 11 As shown, the mixing step occurs within the casing 60. Mixing can result in the blending of filaments 24 and particles 20; for example, the mixing step can be a co-forming process. The mixing of the filament flow 54 and the particle flow 52 can occur at an angle α of about 30° to about 120° and / or about 45° to about 100° and / or about 60° to about 90°. The particles 20 can exhibit a range of Stokes numbers, for example, exhibiting a Stokes number range of at least 50 unit differences and / or at least 100 unit differences and / or at least 150 unit differences and / or at least 200 unit differences and / or at least 250 unit differences. In one example, the size of at least one particle 20 is at least two and / or at least three times the size of at least one other particle 20. The introduction of the particle flow 52 can occur on the upstream and / or downstream side of the filament flow.

[0226] like Figure 11 As shown, in one example of the invention, the mixing of particles 20 and filaments 24 results in a non-random arrangement of particles 20 in the composite material flow 56 based on particle characteristics selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixing properties. In one example, the particle characteristic is size. In one example, the non-random arrangement of particles 20 in the composite material flow 56 includes: a first group 76 of particles 20 comprising at least a majority of larger-sized particles 20 present in a first portion of the longitudinal thickness of the composite material flow 56; and a second group 78 of particles 20 comprising at least a majority of smaller-sized particles present in a second portion of the longitudinal thickness of the composite material flow 56, different from the first portion. In one example, the first portion of the longitudinal thickness of the composite material flow is closer to the upstream side of the composite material flow 56 than the second portion. In another example, the second portion of the longitudinal thickness of the composite material flow 56 is closer to the downstream side of the composite material flow 56 than the first portion. In yet another example, the first portion of the longitudinal thickness of the composite material flow 56 is closer to the upstream side of the composite material flow 56, and the second portion of the longitudinal thickness of the composite material flow 56 is closer to the downstream side of the composite material flow 56.

[0227] like Figure 11As shown, in one example of the invention, the mixing of particles 20 with filaments 24, based on the Stokes number of particles 20, results in a non-random arrangement of particles 20 in the composite material flow 56. In one example, the non-random arrangement of particles 20 in the composite material flow 56 comprises: a first group 76 of particles 20, which includes at least a majority of particles 20 with larger Stokes numbers present in a first portion of the longitudinal thickness of the composite material flow 56; and a second group 78 of particles 20, which includes at least a majority of particles 20 with smaller Stokes numbers present in a second portion of the longitudinal thickness of the composite material flow 56, different from the first portion. In one example, the first portion of the longitudinal thickness of the composite material flow 56 is closer to the upstream side of the composite material flow 56 than the second portion. In another example, the second portion of the longitudinal thickness of the composite material flow 56 is closer to the downstream side of the composite material flow 56 than the first portion. In yet another example, the first portion of the longitudinal thickness of the composite material flow 56 is closer to the upstream side of the composite material flow 56, and the second portion of the longitudinal thickness of the composite material flow 56 is closer to the downstream side of the composite material flow 56.

[0228] In another example, the non-random arrangement of particles in the composite flow causes the particles to exist as a longitudinal gradient in the composite flow based on particle properties selected from a group consisting of: size, shape, mass, density, Stokes number, and their mixing properties. In one example, the particle property is size. In another example, the particle property is Stokes number. In one example, the longitudinal gradient is a continuous gradient. In another example, the continuous gradient exists throughout the entire longitudinal thickness of the composite flow. In yet another example, the longitudinal gradient exists in a form smaller than the entire longitudinal thickness of the composite flow.

[0229] a. particles

[0230] The particulate stream 52 may include less than 50% by weight and / or less than 40% by weight and / or less than 30% by weight and / or less than 20% by weight and / or less than 10% by weight and / or less than 5% by weight and / or less than 3% by weight and / or 0% by weight or about 0% by weight of non-particulate solids additives, such as fibers, pulp fibers, such as wood pulp fibers.

[0231] Multiple particles 20 of particle flow 52 may exhibit a particle size distribution span of greater than 10% and / or greater than 15% and / or greater than 20% and / or greater than 25% and / or greater than 30% and / or greater than 35% and / or greater than 40% and / or greater than 45% and / or greater than 50%.

[0232] The multiple particles 20 of the particle stream 52 can exhibit a Stokes number range of about 50 to about 1000 and / or about 80 to about 800 and / or about 100 to about 600.

[0233] Multiple particles 20 in the particle flow 52 can exhibit a Stokes number difference of less than 1000 and / or less than 800 and / or less than 600 and / or less than 500 and / or less than 400.

[0234] As measured according to the μCT test method described herein, multiple particles 20 of the particle flow 52 can exhibit a size of approximately 0.0001 mm. 3 To approximately 0.001 mm 3 And / or approximately 0.0002 mm 3 To approximately 0.0009 mm 3 And / or approximately 0.0003 mm 3 To approximately 0.0009 mm 3 And / or approximately 0.0005 mm 3 To approximately 0.0008 mm 3 And / or approximately 0.0001 mm 3 To approximately 0.0008 mm 3 And / or approximately 0.0001 mm 3 To approximately 0.0006 mm 3 The average volume range.

[0235] As measured according to the described μCT test method, multiple particles 20 of the particle flow 52 can exhibit a size of less than 0.001 mm. 3 and / or less than 0.0008 mm 3 And / or less than 0.0006 mm 3 and / or less than 0.0005 mm 3 And / or less than 0.0004 mm 3 The average volume difference.

[0236] The multiple particles 20 of the particle stream 52 can have a density of approximately 0.1 g / cm³. 3 Approximately 2.5 g / cm³ 3 and / or approximately 0.3 g / cm³ 3 Approximately 2.0 g / cm³ 3 and / or approximately 0.5 g / cm³ 3 Approximately 2.0 g / cm³ 3 and / or approximately 0.7 g / cm³ 3 Approximately 1.8 g / cm³ 3 and / or approximately 0.8 g / cm³ 3 Approximately 1.8 g / cm³ 3 and / or about 1.0 g / cm³ 3 Approximately 1.5 g / cm³ 3 The density range.

[0237] If the method includes two or more particle streams 52 in the form of a single warp and / or multiple warp, the particles 20 within the two or more particle streams 52 may be the same or different. In other words, the particles 20 within the two or more particle streams 52 may include different compositions and / or exhibit different densities and / or exhibit different particle properties, such as different particle properties selected from the group consisting of: size, shape, mass, density, Stokes number, and their mixing properties.

[0238] The multiple particles 20 of the particle stream 52 can exhibit different shapes, such as regular and / or irregular shapes. In one example, the multiple particles 20 exhibit different irregular shapes.

[0239] The multiple particles 20 of the particle stream 52 may originate from particulate material (not shown) that has been screened, milled and / or ground. Figure 12 The particle size distribution curve of an example of several particles that have been sieved and measured according to the particle size distribution testing method described herein is shown. In addition... Figure 12 In addition to the particle size distribution curve (which shows that multiple particles 20 exhibit a D50 particle size of 300 μm), multiple particles 20 also exhibit the Stokes number and mass % particle size listed in Table 2 below.

[0240]

[0241] Table 2

[0242] Furthermore, the particles of the present invention may also include a more compact particle size distribution profile, as seen in colloidal SAP particles, which tend to be very spherical and exhibit a D50 of about 300 μm, with a particle size range of about 250 μm to 350 μm. Examples of such colloidal SAP particles are commercially available from Sumitomo.

[0243] The plurality of particles 20 in the particle stream 52 may include superabsorbent polymer particles (SAP), fragrance particles, abrasive particles, odor control particles, and mixtures thereof. In one example, the superabsorbent polymer includes a carboxylic acid, such as a cross-linked carboxylic acid.

[0244] The plurality of particles 20 in the particle stream 52 may include more than 80% by weight and / or more than 90% by weight and / or more than 95% by weight and / or about 100% by weight and / or 100% by weight of superabsorbent polymer particles.

[0245] Superabsorbent polymer particles can exhibit a wide range of particle sizes. For industrial hygiene reasons, an average particle size smaller than approximately 30 micrometers is undesirable. Particles with a minimum size greater than approximately 2 mm also produce a gritty feel in the resulting structure, which is undesirable from a consumer aesthetic standpoint. Furthermore, the fluid absorption rate can be affected by particle size. Larger particles have a significantly reduced absorption rate. In one example, the superabsorbent polymer particles have a particle size ranging from approximately 30 micrometers to approximately 2 mm (for virtually all particles). As used herein, “particle size” means a weighted average of the minimum sizes of individual particles.

[0246] In one example, as measured according to the particle size distribution test method described herein, multiple particles may exhibit a D50 particle size of about 100 μm to about 5000 μm and / or about 100 μm to about 2000 μm and / or about 250 μm to about 1200 μm and / or about 250 μm to about 850 μm.

[0247] In one example, multiple particles exist in the structure with a basis weight of approximately 10 gsm to approximately 1000 gsm.

[0248] In one example, multiple particles include: a first particle containing a first composition; and a second particle containing a second composition different from the first composition.

[0249] In one example, the plurality of particles includes a first particle exhibiting a first Stokes number and a second particle exhibiting a second Stokes number different from the first Stokes number, for example, wherein the first Stokes number differs from the second Stokes number by at least 20% and / or at least 30%.

[0250] b. Filament

[0251] The filament may contain polymers, such as thermoplastic polymers, including those selected from the group consisting of polyolefins, polyesters, polyesteramides, polycaprolactone, polyhydroxyalkanoates, polylactic acid, and mixtures thereof. In one example, the thermoplastic polymer is a polyolefin, such as polypropylene, polypropylene copolymers, polyethylene, polyethylene copolymers, and mixtures thereof.

[0252] In one example, the thermoplastic polymer is a biodegradable thermoplastic polymer.

[0253] In one example, the thermoplastic polymer is a compostable thermoplastic polymer.

[0254] Non-limiting examples of suitable polypropylene for manufacturing filaments (such as the filaments of the present invention) are commercially available from LyondellBasell and Exxon-Mobil.

[0255] Any hydrophobic or non-hydrophilic material within the co-molded fiber structure (such as thermoplastic filaments, e.g., polypropylene filaments) can be surface-treated and / or melt-treated with hydrophilic modifiers. Non-limiting examples of surface-treatment hydrophilic modifiers include surfactants such as Triton X-100. Non-limiting examples of melt-treatment hydrophilic modifiers added to the polymer composition (polymer melt) such as polypropylene melt prior to spinning of the filament include hydrophilic melt-modified additives such as VW351 and / or S-1416 from Polyvel and Irgasurf from Ciba. Hydrophilic modifiers can be associated with hydrophobic or non-hydrophilic materials at any suitable level known in the art. In one example, the hydrophilic modifier is associated with the polymer composition (such as hydrophobic and / or non-hydrophobic materials within the polymer composition) at a level greater than 0% to less than about 20% and / or greater than 0% to less than about 15% and / or greater than 0.1% to less than about 10% and / or greater than 0.1% to less than about 5% and / or greater than 0.5% to less than about 3% based on the dry weight of the hydrophobic or non-hydrophobic materials. In another example, the hydrophilic modifier may be present in the filament at a level of about 0.1% to about 10% by weight and / or about 0.5% to about 7% by weight and / or about 1% to about 5% by weight.

[0256] c. Non-particulate solid additives

[0257] In one example, the non-particulate solid additive of the present invention (e.g., fibers, such as pulp fibers, e.g., wood pulp fibers) may be selected from the group consisting of: cork kraft pulp fibers, hardwood pulp fibers, and mixtures thereof. Non-limiting examples of hardwood pulp fibers include fibers derived from a fiber source selected from the group consisting of: acacia, eucalyptus, maple, oak, aspen, birch, cottonwood, alder, ash, cherry, elm, hickory, poplar, bakelite, walnut, locust, sycamore, beech, catalpa, sassafras, ash, acacia, jacaranda, and magnolia. Non-limiting examples of cork pulp fibers include fibers derived from a fiber source selected from the group consisting of: pine, spruce, fir, larch, hemlock, cypress, and cedar. In one example, the hardwood pulp fiber includes tropical hardwood pulp fibers. Non-limiting examples of suitable tropical hardwood pulp fibers include eucalyptus pulp fibers, acacia pulp fibers, and mixtures thereof.

[0258] In one example, the wood pulp fibers include cork pulp fibers derived from kraft paper processes from southern climates, such as Southern Cork Kraft (SSK) pulp fibers. In another example, the wood pulp fibers include cork pulp fibers derived from kraft paper processes from northern climates, such as Northern Cork Kraft (NSK) pulp fibers.

[0259] When present in the methods and / or structures of the present invention, the wood pulp fibers may be present in a weight ratio of softwood pulp fibers to hardwood pulp fibers of 100:0 and / or 90:10 and / or 86:14 and / or 80:20 and / or 75:25 and / or 70:30 and / or 60:40 and / or about 50:50 and / or up to 0:100 and / or up to 10:90 and / or up to 14:86 and / or up to 20:80 and / or up to 25:75 and / or up to 30:70 and / or up to 40:60. In one example, the weight ratio of softwood pulp fibers to hardwood pulp fibers is from 86:14 to 70:30.

[0260] In one example, the non-particulate solid additive of the present invention comprises one or more trichomes. Non-limiting examples of suitable sources for obtaining trichomes (especially trichome fibers) are plants from the family Lamiaceae, commonly known as the mint family. Examples of suitable species from the Lamiaceae family include *Stachys byzantina* (also known as *Stachys lanata*), commonly called lamb's ear, woollybetony, or woundwort. As used herein, the term *Stachys byzantina* also includes cultivated varieties such as *PrimroseHeron*, *Helene von Stein* (sometimes called *Big Ears*), *CottonBoll*, *Variegated* (sometimes called *Striped Phantom*), and *Silver Carpet*.

[0261] In another example, the non-particulate solid additive of the present invention may include one or more superabsorbent polymer fibers, provided that the method and / or structure includes a plurality of particles according to the present invention.

[0262] d. Forming a structure

[0263] To ultimately form the structure 26 of the present invention, a composite material stream 56 comprising multiple filaments 24 and multiple particles 20, and optionally a variety of non-particulate solid additives 64, is collected on a collection device 25, which may be, for example, a ventilated dry fabric or other fabric or patterned molded component and / or rollers and / or films and / or pre-existing nonwoven fiber web material, such as a top sheet, like a secondary top sheet, which may be carried on a separate collection device (such as a fabric). The step of collecting the composite material stream 56 on the collection device 25 may include subjecting the resulting structure 26 to a consolidation step while on the collection device 25, thereby pressing the structure 26 (when present on the collection device 25) between roller gaps, for example, formed by a flat or uniform surface rubber roller and a flat or uniform surface or patterned, heated (with oil) or unheated metal roller.

[0264] The process of collecting the samples onto the collection device can be assisted by a vacuum chamber located below the collection device 25.

[0265] In one example, the filament source 30 of method 50 can be a meltblown die, such as a multi-row capillary die, a knife-edge die, or a combination thereof. In one example, the meltblown die is a multi-row capillary die. In one example, the multi-row capillary die includes a plurality of filament forming orifices coaxially positioned within fluid release orifices that supply drawing air to the polymer exiting the filament forming orifices. The fluid release orifices may be positioned concentrically or substantially concentrically around the filament forming orifices. In one example, fluid (e.g., drawing air) exits one or more fluid release orifices, for example, each fluid release orifice being parallel or substantially parallel to the filament exiting one or more filament forming orifices.

[0266] In one example of method 50 of the present invention, the method includes the following steps:

[0267] a. Provide multiple filaments;

[0268] b. Providing a plurality of particles and optional non-particle solid additives, wherein at least a portion of the plurality of solid additives comprises a plurality of particles, wherein the particles exhibit a wide range of particle size distributions; and

[0269] c. Blend the multiple filaments with the various solid additives;

[0270] d. Collect multiple blended filaments and various solid additives on a collecting device to form a structure.

[0271] This results in the multiple particles being dispersed unevenly in the fiber structure based on their particle size.

[0272] In one example, the method includes the following steps: a) providing a filament stream comprising multiple filaments, a particle stream comprising multiple particles (e.g., multiple SAP particles), and an optional non-particulate solids additive stream, all streams being separate from each other and / or net streams (e.g., less than 10 wt% and / or less than 5 wt% and / or less than 3 wt% and / or about 0 wt% and / or 0 wt% of material different from its corresponding material); b) blending the multiple particles with the multiple filaments; c) optionally blending the multiple non-particulate solids additive with the multiple filaments; d) collecting the filaments, particles, and optional non-particulate solids additive on a collecting device to form a structure, such as a fibrous structure, for example, an absorbent material, such as an absorbent core material.

[0273] In one example, both particulate and non-particulate solid additives (such as fibers, e.g., wood pulp fibers) can be introduced into the filament stream as a solid additive (particulate and non-particulate) stream. In this case, the weight of the non-particulate solid additives may be relatively low compared to the weight of the particulates. Furthermore, multiple particulates may exhibit at least one Stokes number, and multiple pulp fibers may exhibit at least one Stokes number different from the at least one Stokes number of the multiple particulates. In one example, the at least one Stokes number of the multiple particulates differs from the at least one Stokes number of the multiple non-particulate solid additives by at least 20% and / or at least 30%.

[0274] As described above, the blending step in this method can occur within a casing (shell), such as a molding box, like a co-molding box.

[0275] In one example, the step of blending multiple filaments with multiple particles includes introducing multiple particles into the flow of multiple filaments at an angle of about 10° to about 170° and / or about 20° to about 150° and / or about 30° to about 130° and / or about 30° to about 120° and / or about 45° to about 100° and / or about 60° to about 90° relative to the flow of multiple filaments.

[0276] In one example, multiple particles are non-uniformly distributed within the fiber structure, such that particles concentrated near one side of the fiber structure exhibit a particle size at least twice that of particles aggregated near the opposite side of the fiber structure. Multiple particles may also be non-uniformly distributed within the fiber structure, such that particles concentrated near one side of the fiber structure exhibit a particle size at least three times that of particles aggregated near the opposite side of the fiber structure.

[0277] In one example, multiple particles are non-uniformly distributed within the fiber structure, such that particles concentrated near the first third of the fiber structure's thickness exhibit a particle size at least twice that of particles concentrated near the relative third of the fiber structure's thickness. Multiple particles may also be non-uniformly distributed within the fiber structure, such that particles concentrated near the first third of the fiber structure's thickness exhibit a particle size at least three times that of particles concentrated near the relative third of the fiber structure's thickness.

[0278] Non-limiting method embodiments for manufacturing the structure of the present invention

[0279] Utilize Figure 13 The following non-limiting embodiments, namely method embodiments 1 to 6, are provided for the example of method 50 according to the present invention. Figure 13 This includes multiple warp beams AE, such as granulated mixed warp beams AC and loosely woven fabric warp beams DE. A given method may utilize one or more granulated mixed warp beams AC. Furthermore, a given method may additionally use one or more loosely woven fabric warp beams DE. Various method embodiments 1 to 6 utilize different materials, different conditions, and / or different numbers and / or configurations of warp beams.

[0280] like Figure 13 As shown, method embodiments 1 to 6 can utilize a single warp beam, two warp beams, three warp beams and / or more warp beams. For example, the warp beam can simply include a die to spin filaments onto a collecting device and / or onto a surface with a granular structure formed on the collecting device or onto both, thus producing a loose fabric layer from the warp beam, which is referred to as a loose fabric warp beam.

[0281] For a multi-warp system, the following definition applies: a series of warp beams (warp beam A, warp beam B, warp beam C, etc.), each warp beam letter is defined by the order in which it deposits material onto the collection device 25 (warp beam A is laid on the bare collection belt or on a loose fabric layer located on the collection belt or even on a pre-existing nonwoven fiber web material located on the collection belt, warp beam B is laid on the material (e.g., a fiber structure) already deposited by warp beam A, and warp beam C is laid on the material already deposited by warp beams A and B).

[0282] Each warp beam combines at least one or more different material categories.

[0283] Discrete short fibers = 72 (e.g., semi-treated or fully treated pulp, EUC fibers, CS10 fibers, and mixtures thereof).

[0284] Continuous filaments = 24 (e.g., meltblown fibers such as PP, PE, other polyolefins, PLA, PHA, block copolymers such as Vistamaxx)

[0285] Particle size = 20 (e.g., SAP, fragrance microcapsules, odor control particles, abrasive particles). The particle delivery nozzle can be oriented along CD on the upstream or downstream side of the warp shaft and / or forming box (shell).

[0286] More than one nozzle can be installed on each warp axis, thereby enabling the achievement of particle and particle size, shape, mass, and / or Stokes number gradients in the longitudinal thickness of the composite material flow and / or the z-direction thickness of the resulting fiber structure generated by collecting the composite material flow on the collecting device 25. The nozzles can also be designed such that only a portion of the nozzle delivers particles, for example, to create longitudinal stripes in the resulting fiber structure.

[0287] When present, each material 72, 24, and 20 in each warp can be controlled independently and can be the same as or different from one or more materials in other warp. Each material can also be processed with different settings (angle, speed, etc.). Similarly, in a single warp, more than one type of particle can be delivered (injected).

[0288] Table 3 below provides an overview of method embodiments 1a to 6.

[0289] Overview of Method Implementation Examples

[0290]

[0291] Method Example 1a (low basis weight, 100 gsm, weak size gradient distribution, no SAP particles near the particle surface area) Domain - Local Region :

[0292] A structure is generated intended for use as an absorbent system in disposable hygiene products, wherein the SAP particles have an approximately uniform size distribution in the z-direction. SAP is absent in the near-surface region to prevent leakage of SAP from the material. Figure 13 The single warp beam is used in method embodiment 1a. Optionally, one or more sparse warp beams can be used to produce sparse fabric on either side or both sides of the structure formed by method embodiment 1a. Details of method embodiment 1a are listed in Table 4 below.

[0293]

[0294] Table 4

[0295] like Figure 14A , Figure 14B and Figure 14C As shown, the structure formed by method embodiment 1a exhibits a non-random arrangement of particles in the formed fiber structure.

[0296] Method Example 1b (High basis weight, 200 gsm, SAP particle size gradient, low SAP content in surface region) :

[0297] The resulting structure is intended for use as an absorbent system in disposable hygiene products, wherein larger SAP particles are distributed towards the top of the material and smaller SAP particles are distributed towards the bottom to prevent gel blockage and improve material utilization. Figure 13 The single warp beam is used in method embodiment 1b. Optionally, one or more sparse warp beams can be used to produce sparse fabric on either side or both sides of the structure formed by method embodiment 1b. Details of method embodiment 1b are listed in Table 5 below.

[0298]

[0299] Table 5

[0300] like Figure 15A , Figure 15B and Figure 4C As shown, the structure formed by method embodiment 1b exhibits a non-random arrangement of particles in the formed fiber structure.

[0301] Method Example 2 :

[0302] A structure is generated intended for use as an absorbent system in disposable hygiene products, wherein the liquid effectively and initially moves into the material in the z-direction, and diffuses towards the bottom of the material away from the skin. Figure 13 Multiple warp beams (three in this case) are used in Method Embodiment 2. Optionally, one or more sparse fabric warp beams can be used to produce sparse fabric on either side or both sides of the structure formed by Method Embodiment 2. Details of Method Embodiment 2 are listed in Table 6 below.

[0303]

[0304] Table 6

[0305] The resulting structure (simulated SAP size distribution) exhibits a total basis weight of 150 gsm, with 80 gsm of SAP particles added.

[0306] Method Example 3 :

[0307] This design produces a structure intended for use as a pre-wetted cleaning pad (e.g., a floor cleaning pad) for cleaning floors and other hard surfaces. The cleaning pad is usable on both sides and has a high capacity for storing liquid during manufacturing and storage, with effective release during product use. Liquid delivery occurs from the storage layer at the center of the pad to the surface layer that contacts the surface to be cleaned (e.g., a floor). Figure 13Multiple warp beams (three in this case) are used in method embodiment 3. Optionally, one or more sparse fabric warp beams can be used to produce sparse fabric on either side or both sides of the structure formed by method embodiment 3. Details of method embodiment 3 are listed in Table 7 below.

[0308]

[0309] Table 7

[0310] Method Example 4 :

[0311] A single warp axis is used to generate a structure intended for use as an absorption system in disposable hygiene products, wherein SAP with a wide particle size distribution is used, wherein smaller SAP particles are not present in the surface layer to prevent gel clogging. Figure 13 The single warp beam is used in method embodiment 4. Optionally, one or more sparse warp beams can be used to produce sparse fabric on either side or both sides of the structure formed by method embodiment 4.

[0312] This method deposits material onto a pre-existing nonwoven fiber web material, such as a top sheet, like a 24gsm carded nonwoven secondary top sheet from YanJan, located on a collection device.

[0313] Details of method embodiment 4 are listed in Table 8 below.

[0314]

[0315]

[0316] Table 8

[0317] Example 5 :

[0318] A structure is generated intended for use as an absorbent system in disposable hygiene products, wherein SAP with a wide particle size distribution is used, wherein larger SAP particles are not present in the surface layer, so as to prevent the granular hardness of the material by embedding the larger SAP particles in the middle of the fiber structure. Figure 13 Multiple warp beams (two in this case) are used in method embodiment 5. Optionally, one or more sparse fabric warp beams can be used to produce sparse fabric on either side or both sides of the structure formed by method embodiment 5. Details of method embodiment 5 are listed in Table 9 below.

[0319]

[0320]

[0321] Table 9

[0322] Method Example 6 :

[0323] Structures are developed intended for use as absorbent systems in disposable hygiene products, where SAP is present only in a portion of the product (e.g., towards the center) to reduce the cost of SAP material that does not contribute to product performance. Figure 13 Multiple warp beams (two in this case) are used in method embodiment 6. Optionally, one or more sparse fabric warp beams can be used to produce sparse fabric on either side or both sides of the structure formed by method embodiment 6. Details of method embodiment 6 are listed in Table 10 below.

[0324]

[0325] Table 10

[0326] structure

[0327] The structures of the present invention (e.g., fibrous structures, such as absorbent materials, such as absorbent core materials) produced by the inventive method of the present invention comprise multiple filaments and multiple particles. In one example, multiple filaments and multiple particles are blended together to form a co-shaped structure. In addition to filaments and particles, the structures of the present invention may also include a variety of non-particulate solid additives, such as fibers, such as pulp fibers, such as wood pulp fibers.

[0328] The structure of the present invention (e.g., a fibrous structure, such as an inelastic fiber structure) comprises multiple filaments and multiple superabsorbent polymer particles, and optionally multiple pulp fibers. The filaments, superabsorbent polymer particles, and optionally pulp fibers can be blended together. In one example, the structure is a co-molded structure. On a dry basis, the filaments may be present in the structure of the present invention at levels of less than 90 wt% and / or less than 80 wt% and / or less than 65 wt% and / or less than 50 wt% and / or greater than 5 wt% and / or greater than 10 wt% and / or greater than 20 wt% and / or about 10 wt% to about 50 wt% and / or about 25 wt% to about 45 wt%.

[0329] On a dry basis, particles may be present in the structure of the invention at a level greater than 10% by weight and / or greater than 25% by weight and / or greater than 50% by weight and / or less than 100% by weight and / or less than 95% by weight and / or less than 90% by weight and / or less than 85% by weight and / or about 30% by weight to about 95% by weight and / or about 50% by weight to about 85% by weight.

[0330] On a dry basis, when non-particulate solid additives are present, they may be present in the structure of the invention at a level greater than 10% by weight and / or greater than 25% by weight and / or greater than 50% by weight and / or less than 100% by weight and / or less than 95% by weight and / or less than 90% by weight and / or less than 85% by weight and / or about 30% by weight to about 95% by weight and / or about 50% by weight to about 85% by weight.

[0331] The filaments and particles may be present in the structure of the invention at a filament-to-particle weight ratio greater than 10:90 and / or greater than 20:80 and / or less than 90:10 and / or less than 80:20 and / or about 25:75 to about 50:50 and / or about 30:70 to about 45:55. In one example, the filaments and particles are present in the structure of the invention at a filament-to-particle weight ratio greater than 0 but less than 1.

[0332] The filaments and non-particulate solid additives (when present) may be present in the structure of the invention at a weight ratio of filaments to non-particulate solid additives greater than 10:90 and / or greater than 20:80 and / or less than 90:10 and / or less than 80:20 and / or about 25:75 to about 50:50 and / or about 30:70 to about 45:55. In one example, the filaments and non-particulate solid additives (when present) are present in the structure of the invention at a weight ratio of filaments to non-particulate solid additives greater than 0 but less than 1.

[0333] In one example, as measured according to the basis weight testing method described herein, the structure of the present invention exhibits a basis weight of about 10 gsm to about 1000 gsm and / or about 10 gsm to about 500 gsm and / or about 15 gsm to about 400 gsm and / or about 15 gsm to about 300 gsm. In another example, as measured according to the basis weight testing method described herein, the structure of the present invention exhibits a basis weight of about 10 gsm to about 200 gsm and / or about 20 gsm to about 150 gsm and / or about 25 gsm to about 125 gsm and / or about 30 gsm to about 100 gsm and / or about 30 gsm to about 80 gsm. In yet another example, as measured according to the basis weight test method described herein, the structure of the present invention exhibits a basis weight of about 80 gsm to about 1000 gsm and / or about 125 gsm to about 800 gsm and / or about 150 gsm to about 500 gsm and / or about 150 gsm to about 300 gsm.

[0334] In one example, the structure of the present invention is a co-formed fiber structure, such as an inelastic co-formed fiber structure, comprising a core component and a plurality of core filaments. The core component comprises a plurality of particles (such as SAP particles) and optional non-particulate solid additives (such as fibers, such as pulp fibers, e.g., wood pulp fibers), the plurality of core filaments being blended with the particles and non-particulate solid additives (when present). The co-formed fiber structure may also include a sparse fabric component, which may contain no or substantially no particles and non-particulate solid additives, comprising a plurality of sparse fabric filaments, which may, for example, be the same as and / or different from the core filaments in chemical composition and are directly deposited (e.g., spun) onto one or more surfaces of the core component. The sparse fabric component (e.g., sparse fabric filaments) may be bonded (e.g., thermally bonded) to the core component (e.g., core component filaments) and / or the particles and / or non-particulate solid additives (when present).

[0335] In one example, the core component is the component exhibiting the largest basis weight within the co-formed fiber structure. In one example, as measured according to the basis weight testing method described herein, the core component present in the co-formed fiber structure of the present invention exhibits a basis weight greater than 50% and / or greater than 55% and / or greater than 60% and / or greater than 65% and / or greater than 70% and / or less than 100% and / or less than 95% and / or less than 90% of the total basis weight of the co-formed fiber structure. In another example, as measured according to the basis weight testing method described herein, the core component exhibits a basis weight less than 20 gsm and / or less than 15 gsm and / or less than 12 gsm and / or less than 10 gsm and / or less than 8 gsm and / or less than 6 gsm and / or greater than 2 gsm and / or greater than 4 gsm.

[0336] In one example, at least one core component of the co-formed fiber structure includes a variety of non-particulate solid additives, such as pulp fibers, including wood pulp fibers and / or non-wood pulp fibers.

[0337] In one example, as measured according to the basis weight testing method described herein, the loose fabric component exhibits a total basis weight of co-formed fiber structure that is less than 25% and / or less than 20% and / or less than 15% and / or less than 10% and / or less than 7% and / or less than 5% and / or greater than 0% and / or greater than 1%. In another example, as measured according to the basis weight testing method described herein, the loose fabric component exhibits a basis weight of 10 gsm or less and / or less than 10 gsm and / or less than 8 gsm and / or less than 6 gsm and / or greater than 5 gsm and / or less than 4 gsm and / or greater than 0 gsm and / or greater than 1 gsm.

[0338] In one example, at least one loose fabric component is adjacent to at least one core component within the co-formed fiber structure. In another example, at least one core component is located between two loose fabric components within the co-formed fiber structure.

[0339] In one example, as measured according to the average diameter test method described herein, at least one of the loosely woven filaments exhibits an average fiber diameter of less than 50 μm and / or less than 25 μm and / or less than 10 μm and / or at least 1 μm and / or greater than 1 μm and / or greater than 3 μm.

[0340] As measured according to the average diameter test method described herein, the average fiber diameter of the core filament is less than 250 μm and / or less than 200 μm and / or less than 150 μm and / or less than 100 μm and / or less than 50 μm and / or less than 30 μm and / or less than 25 μm and / or less than 10 μm and / or greater than 1 μm and / or greater than 3 μm.

[0341] In one example, the co-formed fiber structure of the present invention may include any suitable amount of filaments (core filaments and / or loosely woven filaments) and any suitable amount of solid additives. For example, the co-formed fiber structure may include about 10% to about 70% and / or about 20% to about 60% and / or about 30% to about 50% of filaments by dry weight of the co-formed fiber structure, and about 90% to about 30% and / or about 80% to about 40% and / or about 70% to about 50% of solid additives, such as wood pulp fibers, by dry weight of the co-formed fiber structure.

[0342] In one example, the filaments and particles of the present invention may exist in the co-formed fiber structure according to the present invention at a filament to particle weight ratio of at least about 1:1 and / or at least about 1:1.5 and / or at least about 1:2 and / or at least about 1:2.5 and / or at least about 1:3 and / or at least about 1:4 and / or at least about 1:5 and / or at least about 1:7 and / or at least about 1:10.

[0343] In one example, when present in a co-formed fiber structure, the non-particulate solid additive may be present in the co-formed fiber structure according to the invention at a weight ratio of at least about 1:1 and / or at least about 1:1.5 and / or at least about 1:2 and / or at least about 1:2.5 and / or at least about 1:3 and / or at least about 1:4 and / or at least about 1:5 and / or at least about 1:7 and / or at least about 1:10 of filament to non-particulate solid additive.

[0344] In one example, non-particulate solids additives (e.g., fibers, such as pulp fibers, like wood pulp fibers) may be selected from the group consisting of: cork kraft pulp fibers, hardwood pulp fibers, and mixtures thereof. Non-limiting examples of hardwood pulp fibers include fibers derived from fiber sources selected from the group consisting of: acacia, eucalyptus, maple, oak, aspen, birch, cottonwood, alder, ash, cherry, elm, hickory, poplar, bakelite, walnut, locust, sycamore, beech, catalpa, sassafras, ash, acacia, jacaranda, and magnolia. Non-limiting examples of cork pulp fibers include fibers derived from fiber sources selected from the group consisting of: pine, spruce, fir, larch, hemlock, cypress, and cedar. In one example, hardwood pulp fibers include tropical hardwood pulp fibers. Non-limiting examples of suitable tropical hardwood pulp fibers include eucalyptus pulp fibers, acacia pulp fibers, and mixtures thereof.

[0345] In one example, the wood pulp fibers include cork pulp fibers derived from kraft paper processes and originating from southern climates, such as Southern Cork Kraft (SSK) pulp fibers. In another example, the wood pulp fibers include cork pulp fibers derived from kraft paper processes and originating from northern climates, such as Northern Cork Kraft (NSK) pulp fibers.

[0346] The wood pulp fibers present in the co-formed fiber structure can be present in a weight ratio of softwood pulp fibers to hardwood pulp fibers of 100:0 and / or 90:10 and / or 86:14 and / or 80:20 and / or 75:25 and / or 70:30 and / or 60:40 and / or about 50:50 and / or up to 0:100 and / or up to 10:90 and / or up to 14:86 and / or up to 20:80 and / or up to 25:75 and / or up to 30:70 and / or up to 40:60. In one example, the weight ratio of softwood pulp fibers to hardwood pulp fibers is from 86:14 to 70:30.

[0347] In one example, the fibrous structure of the present invention comprises one or more trichomes. Non-limiting examples of suitable sources for obtaining trichomes (especially trichome fibers) are plants in the family Lamiaceae, commonly known as the mint family. Examples of suitable species in the Lamiaceae family include *Stachys byzantina* (also known as *Stachys lanata*), commonly called lamb's ear, woolly betony, or woundwort. As used herein, the term *Stachys byzantina* also includes cultivated varieties such as *Primrose Heron*, *Helene von Stein* (sometimes called *Big Ears*), *Cotton Boll*, *Variegated* (sometimes called *Striped Phantom*), and *Silver Carpet*.

[0348] Non-limiting examples of suitable polypropylene for manufacturing filaments (such as the filaments of the present invention) are commercially available from LyondellBasell and Exxon-Mobil.

[0349] Any hydrophobic or non-hydrophilic material within the co-molded fiber structure (such as thermoplastic filaments, e.g., polypropylene filaments) can be surface-treated and / or melt-treated with hydrophilic modifiers. Non-limiting examples of surface-treatment hydrophilic modifiers include surfactants such as Triton X-100. Non-limiting examples of melt-treatment hydrophilic modifiers added to the polymer composition (polymer melt) such as polypropylene melt prior to spinning of the filament include hydrophilic melt-modified additives such as VW351 and / or S-1416 from Polyvel and Irgasurf from Ciba. Hydrophilic modifiers can be associated with hydrophobic or non-hydrophilic materials at any suitable level known in the art. In one example, the hydrophilic modifier is associated with the polymer composition (such as hydrophobic and / or non-hydrophobic materials within the polymer composition) at a level greater than 0% to less than about 20% and / or greater than 0% to less than about 15% and / or greater than 0.1% to less than about 10% and / or greater than 0.1% to less than about 5% and / or greater than 0.5% to less than about 3% based on the dry weight of the hydrophobic or non-hydrophobic materials. In another example, the hydrophilic modifier may be present in the filament at a level of about 0.1% to about 10% by weight and / or about 0.5% to about 7% by weight and / or about 1% to about 5% by weight.

[0350] In one example, the fiber structure according to the invention comprises a plurality of filaments and a plurality of solid particles, wherein the plurality of filaments and the plurality of solid particles are blended together to form the fiber structure such that the plurality of solid particles exist throughout the thickness of the fiber structure with different average particle size values.

[0351] Multiple filaments can include multiple filaments, such as water-insoluble filaments.

[0352] Multiple filaments can include multiple fibers, such as water-insoluble fibers.

[0353] The filament may contain polymers, such as thermoplastic polymers selected from the group consisting of: polyolefins, polyesteramides, polycaprolactone, polyhydroxyalkanoates, polylactic acid, and mixtures thereof. In one example, the thermoplastic polymer is a polyolefin, such as a polyolefin selected from the group consisting of: polypropylene, polypropylene copolymers, polyethylene, polyethylene copolymers, and mixtures thereof.

[0354] In one example, the thermoplastic polymer is a biodegradable thermoplastic polymer.

[0355] In one example, the thermoplastic polymer is a compostable thermoplastic polymer.

[0356] In one example, the fibrous structure comprises multiple particles selected from the group consisting of inorganic particles, organic particles, and mixtures thereof.

[0357] In one example, the fibrous structure includes multiple solid particles, including odor control particles and / or fragrance particles, and / or abrasive particles.

[0358] In one example, the fibrous SAP particles include absorbent material particles, such as absorbent material particles that include superabsorbent polymer particles (e.g., carboxylic acids, such as cross-linked carboxylic acids).

[0359] In one example, as measured according to the particle size distribution test method, SAP particles exhibit a D50 particle size of about 20 μm to about 2000 μm and / or about 50 μm to about 2000 μm and / or about 100 μm to about 2000 μm and / or about 250 μm to about 1200 μm and / or about 250 μm to about 850 μm and / or about 150 μm to about 850 μm and / or about 100 μm to about 600 μm and / or about 100 μm to about 400 μm.

[0360] In one example, SAP particles exist in the fiber structure with a basis weight of approximately 10 gsm to approximately 1000 gsm.

[0361] The fiber structure of the present invention may include: a first group of solid particles, the first group of solid particles comprising a first component, such as SAP particles; and a second group of solid particles, the second group of solid particles comprising a second component different from the first component.

[0362] In one example, the SAP particles include a first group of SAP particles exhibiting a first Stokes number and a second group of SAP particles exhibiting a second Stokes number different from the first Stokes number. In one example, the first Stokes number differs from the second Stokes number by at least 20% and / or at least 30%.

[0363] Multiple SAP particles can exist in the thickness of the fiber structure with an average particle size gradient.

[0364] Multiple solid particles can exist in the thickness of the fiber structure with a continuous gradient of average particle size values.

[0365] The fiber structure may also include multiple pulp fibers mixed with multiple filaments and multiple SAP particles.

[0366] The multiple pulp fibers may include wood pulp fibers.

[0367] The multiple pulp fibers may include non-wood pulp fibers.

[0368] In one example, particles are added to the method such that the resulting structure (e.g., a fiber structure) includes a non-uniform concentration of particles in the Z direction of the fiber structure.

[0369] In one example, particles are added to the method such that the resulting structure (e.g., a fiber structure) includes a first region and a second region different from the first region, the first region including particles exhibiting a first particle size and the second region including particles exhibiting a second particle size different from the first particle size.

[0370] Figure 16 Non-limiting examples of particulate 20 (e.g., SAP particulates) and non-particulate solids additives (e.g., pulp fibers 72) are shown. Figure 16 It can be seen that one reason why SAP particles have a large Stokes number is that their geometric mean of long and short axes is larger than that of pulp fibers.

[0371] Test methods

[0372] Unless otherwise specified, all tests described herein (including those defined in the definitions section and the following test methods) are performed on samples that have been conditioned for at least 24 hours prior to testing in a conditioning chamber at a temperature of 23°C ± 1.0°C and a relative humidity of 50% ± 2%. These will be considered standard conditioning temperatures and humidity. All plastic and cardboard packaging products (if any) must be carefully removed from the samples prior to testing. Unless otherwise specified, all tests are conducted in such conditioning chambers under the same environmental conditions as in such chambers. Discard any damaged products. Do not test samples with defects such as wrinkles, tears, holes, etc. Calibrate all instruments according to the manufacturer's instructions. The stated number of duplicate samples to be tested is the minimum.

[0373] Basis weight test method

[0374] The basis weight of structures was measured on stacks of eight to twelve structures (such as fiber structures, or absorbent materials, such as absorbent core materials) using a top-loaded analytical balance with a resolution of ±0.001 g. All samples were prepared using precision cutting dies with dimensions of 8.890 cm × 8.890 cm or 10.16 cm × 10.16 cm.

[0375] Before cutting the sample, condition it at standard temperature and humidity for at least 10 minutes. Use a precision cutting die to cut the sample into squares. Combine the cut squares to form a stack of eight to twelve sample thicknesses. Measure and record the mass of the sample stack to an accuracy of 0.001 g.

[0376] calculate:

[0377]

[0378] The report results are accurate to 0.1 g / m³. 2 A precision cutter similar to the one mentioned above can be used to change or alter the sample size so that the sample area in the stack is at least 645 square centimeters.

[0379] Before being combined with other fiber structures, the individual fiber structures that are ultimately combined to form the article can be collected during their respective manufacturing operations, and then the basis weight of the respective fiber structures is measured as described above.

[0380] Average diameter test method

[0381] There are many ways to measure the diameter of fibrous elements (e.g., filaments and / or fibers). One method is optical measurement. The fibrous structure, including the fibrous elements (e.g., filaments), is cut into rectangular samples of approximately 20 mm by 35 mm. The samples are then coated with gold using a SEM sputtering coater (EMS Inc., Pennsylvania, USA) or equivalent, making the filaments relatively opaque. Typical coating thicknesses are between 50 nm and 250 nm. The samples are then fixed between two standard microscope slides and clamped together using a small adhesive. The samples are imaged using a 10X objective on an Olympus BHS microscope or equivalent, with the microscope collimating lens moved as far away from the objective as possible. Images are captured using a Nikon D1 digital camera or equivalent. The spatial distance of the images is calibrated using a glass microscope micrometer. The approximate resolution of the images is 1 μm / pixel. The images typically show a distinct bimodal distribution in the intensity histogram, corresponding to the filament and the background. An acceptable bimodal distribution can be achieved using camera adjustments or different basis weights. Typically, 10 images are taken for each sample, and the results of the image analysis are averaged.

[0382] The images were analyzed in a manner similar to that described by B. Pourdeyhimi, R. and R. Dent in “Measuring fiber diameter distribution in nonwovens” (Textile Res. J. 69(4) 233-236, 1999). Digital images were analyzed by computer using MATLAB (version 6.1) or equivalents and the MATLAB Image Processing Toolbox (version 3) or equivalents. First, the images were converted to grayscale. Then, the images were binaryed to black and white pixels using a threshold that minimized the within-group variance of the thresholded black and white pixels. Once the images were binaryed, they were skeletonized to locate the center of each fiber in the image. A distance transform of the binaryized image was also computed. The scalar product of the skeletonized image and the distance map provided an image whose pixel intensity was either zero or the fiber radius at that location. Pixels within a radius of the junction between two overlapping fibers were not counted if the distance represented by a pixel was less than the radius of the junction. The remaining pixels were then used to compute a length-weighted histogram of the diameters of the filaments contained in the image.

[0383] MicroCT (μCT) testing methods

[0384] 3D X-ray imaging of samples is obtained using micro-CT instruments such as the ScancoμCT 50 or ScancoμCT 100HE (Scanco Medical AG, Switzerland). The micro-CT instrument is a cone-beam photomicroscope with a shielded enclosure. A maintenance-free X-ray tube is used as the light source with an adjustable focal diameter. The X-ray beam passes through the sample, where some of the X-rays are attenuated according to the sample's composition, structure, and overall volume. The degree of attenuation is related to the mass density of the sample through which the X-rays pass. The transmitted / attenuated X-rays continue into a digital detector array, producing a 2D projection image of the sample. A 3D image of the sample is generated by collecting hundreds of individual 2D projections at different directional angles as the sample rotates. These directionally correlated 2D projections are then reconstructed into a single 3D image. The instrument is connected to a computer running software to control image acquisition and save the raw data.

[0385] Micro-computation used to determine the average particle size distribution of a fibrous structure (FS):

[0386] Porosity is the ratio between the vacant space and the total space occupied by the fiber structure. Porosity under this testing method can be calculated from a μCT scan of the fiber structure by segmenting the vacant space using thresholding and determining the ratio of vacant voxels to total voxels. Similarly, the solid volume fraction (SVF) is also calculated from a μCT scan of the fiber structure and is the ratio between the solid space and the total space; SVF is calculated as the ratio of solid voxels to total voxels. Both porosity and SVF are average scalar values ​​and do not provide structural information, unlike the “pore size distribution” along the height of the fiber structure, the “average thickness of the fibers in the fiber structure” along the longitudinal direction (MD), or the “particle (e.g., SAP particle) size distribution” as a function of the fiber structure depth.

[0387] To characterize the 3D structure of the fiber, samples were imaged using a μCT X-ray scanner capable of acquiring datasets with high isotropic spatial resolution. An example of a suitable instrument is the SCANCO System 50 μCT scanner or the 100HE μCT (Scanco Medical AG, Brüttisellen, Switzerland), with the following operating settings: 45 kVp energy level at 104 μA; 3000 projections; 19 mm field of view; 400 ms accumulation time; averaging of 6 scans; and a voxel size of 6 μm per pixel. After scanning and subsequent data reconstruction, the scanner system creates a 16-bit dataset, called an ISQ file, where gray levels reflect variations in X-ray attenuation, which in turn is related to material density. The ISQ file is then converted to 8 bits using a scaling factor.

[0388] Scanned fiber structure samples are typically prepared by punching out a core approximately 32 mm in diameter from the fiber structure to be scanned. The fiber structure punch is placed flat on low-attenuation foam and then mounted in a 34 mm diameter plastic cylindrical tube for scanning. Scans of the fiber structure punch sample are acquired such that the dataset includes an inner volume of 19 mm to avoid structural modifications from the edges during sample punching. From this dataset, a smaller sub-volume of the sample dataset is extracted from the total cross-section of the scanned fiber structure punch, thereby creating a 3D data plate in which the fiber structure can be accurately and timely qualitatively evaluated.

[0389] To characterize particle distribution, such as SAP particle distribution, the particles (e.g., SAP particles) must be separated from the fibrous structure. This can be easily achieved through thresholding and segmentation. Particles (e.g., SAP particles) have a higher mass density than the surrounding fibrous elements, so a high threshold is implemented to separate the particle component from the fibrous structure (e.g., fibrous elements). Then, to characterize particle distribution in the height direction, a local thickness map algorithm, or LTM, is implemented on the sub-volume dataset. The LTM method begins with an Euclidean distance map (EDM), which specifies that the gray level value is equal to the distance of each solid voxel from its nearest boundary. Based on the EDM data, the 3D solid space representing the particles is further subdivided into spheres whose size matches the EDM values. The voxels enclosed by the spheres are assigned the radius value of the largest sphere. In other words, each solid voxel is assigned the longitudinal value of the largest sphere that fits the boundary of the solid space and contains the specified voxel. The 3D labeled sphere distribution output from LTM data scanning can be viewed as a stack of 2D images in the height direction (or Z direction) and used to estimate the variation in sphere diameter from slice to slice as a function of fiber structure depth. Particle thickness is treated as a 3D dataset, and the average value of all or part of the sub-volume can be evaluated. Calculations and measurements were performed using AVIZO Lite (9.2.0) from Thermo Fisher Scientific and MATLAB (R2018b) from Mathworks.

[0390] Furthermore, to characterize particle distribution, smaller, thresholded particle datasets can be used to identify connected or separated components. For example, connected objects are groups of adjacent voxels whose intensity values ​​fall within a selected threshold range. Once regions are identified, statistics for these regions are output, such as the individual particle volume (number of voxels multiplied by the size of a single voxel) and the coordinates corresponding to the particle center: CenterX, CenterY, Center:[X,Y,Z]. Data processing in Matlab can provide detailed histograms of the distribution as a function of depth.

[0391] On the other hand, smaller datasets that have undergone thresholding can be used to generate contour lines in Avizo without the need for smoothing. Isosurfaces are 3D simulations of isosurface contours rendered against polygonal meshes. The surface area versus volume function in Avizo adds the area of ​​all patch triangles and also evaluates the volume surrounded by the triangles, outputting the data to an Excel spreadsheet.

[0392] Particle size distribution testing method Particle size distribution testing was performed to determine the characteristic particle size of solid additives such as granules. The tests were conducted using ASTM D 502-89, "Standard Test Method for Particle Size of Soaps and Other Detergents," approved May 26, 1989, with further details on the sieve sizes and sieving times used in the analysis. Following Section 7, "Procedures for Using Machine Sieving Methods," clean, dry sieves and discs containing American Standard (ASTM E 11) sieves #4 (4.75 mm), #6 (3.35 mm), #8 (2.36 mm), #12 (1.7 mm), #16 (1.18 mm), #20 (850 μm), #30 (600 μm), #40 (425 μm), #50 (300 μm), #70 (212 μm), #100 (150 μm), #170 (90 μm), and #325 (44 μm) were required to cover the particle size range described herein. Use the above-described sieve set for the specified machine sieving method. A suitable sieve shaker is available from WSTyler Company, Ohio, USA. Shake the test sample to approximately 100 grams for 5 minutes.

[0393] The data is plotted on a semi-logarithmic plot by plotting the logarithmic x-axis with the micron-sized openings of each sieve and the linear y-axis with the finer cumulative mass percentage (CMPF). An example of the above data representation is given in Figure A.4 of ISO 9276-1:1998, “Representation of results of particle size analysis – Part 1: Graphical Representation”. For the purposes of this invention, the characteristic particle size (Dx, x = 10, 50, 90) is defined as the x-axis value of the point where the cumulative mass percentage equals x%, and is calculated by linear interpolation between data points directly above (a) and below (b) the x-value using the following formula:

[0394] Dx=10^[Log(Da)-(Log(Da)-Log(Db))*(Qa-x%) / (Qa-Qb)]

[0395] Where Log is the logarithm with base 10, and Qa and Qb are the measured data immediately above or below x, respectively. th The cumulative mass percentage value; and Da and Db are the mesh size values ​​in micrometers corresponding to these data.

[0396] Example data and calculations :

[0397]

[0398] For D10 (x = 10), the CMPF is 300 micrometers for sieves immediately above 10% (Da) and 212 micrometers for sieves below 10%. The cumulative mass (Qa) is 15.2% for those immediately above 10% and 6.8% for those below 10%. D10 = 10^[Log(300) – (Log(300) – Log(212)) * (15.2% - 10%) / (15.2% - 6.8%)] = 242 micrometers.

[0399] For D90 (x = 90), the CMPF is 1180 micrometers for sieves immediately above 90% (Da) and 850 micrometers for sieves below 90% (Db). The cumulative mass (Qa) is 99.3% for those immediately above 90% and 89.0% for those below 90% (Qb). D90 = 10^[Log(1180) - (Log(1180) - Log(850)) * (99.3% - 90%) / (99.3% - 89.0%)] = 878 micrometers.

[0400] For D50 (x = 50), the CMPF is 600 micrometers for sieves immediately above 50% (Da) and 425 micrometers for sieves below 50% (Db). The cumulative mass (Qa) is 60.3% for those immediately above 50% and 32.4% for those below 50% (Qb). D50 = 10^[Log(600) - (Log(600) - Log(425)) * (60.3% - 50%) / (60.3% - 32.4%)] = 528 micrometers.

[0401] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent the stated value and a range around which it is functionally equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0402] Unless expressly excluded or otherwise limited, every reference cited herein, including any cross-references or related patents or patent applications, and any patent application or patent claiming priority to or benefiting from it, is incorporated herein by reference in its entirety. Reference to any reference is not an endorsement of it as prior art to any disclosed or protected art herein, nor is it an endorsement of any such invention, either on its own or in combination with any one or more references. Furthermore, where any meaning or definition of a term in this invention conflicts with any meaning or definition of the same term in referenced documents, the meaning or definition given to that term in this invention shall prevail.

[0403] While specific embodiments of the invention have been illustrated and described by way of example, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered by the appended claims.

Claims

1. A method for forming a fibrous structure, the method comprising the following steps: A first fluid flow comprising multiple fiber elements is mixed with a second fluid flow comprising multiple first particles within a casing. By controlling the angle and / or velocity at which the multiple first particles from the second fluid flow are introduced into the first fluid flow, a composite fluid flow exhibiting a non-random arrangement of the multiple first particles in the composite fluid flow is formed. The plurality of fiber elements comprises a plurality of filaments, and the plurality of first particles comprises superabsorbent polymer particles. The non-random arrangement of the plurality of first particles in the composite fluid flow causes the plurality of first particles to exist in the composite fluid flow with a longitudinal gradient based on their size. The method further includes the step of collecting the composite fluid flow on a collecting device, such that a fiber structure exhibiting a non-random arrangement of the plurality of first particles in the fiber structure is formed. The non-random arrangement of the plurality of first particles in the fiber structure causes the plurality of first particles to exist in the fiber structure with a gradient in the z-direction based on their size. The second fluid flow intersects the first fluid flow at an angle of 5° to 130° during the method. The plurality of first particles are present in the fiber structure with a basis weight of 10 gsm to 1000 gsm. The plurality of first particles includes at least one particle whose size is at least twice the size of at least one other particle within the plurality of first particles.

2. The method according to claim 1, wherein the plurality of fiber elements comprises a plurality of filaments and a plurality of fibers.

3. The method according to claim 2, wherein the plurality of filaments and the plurality of fibers are blended.

4. The method of claim 1, wherein the step of mixing a first fluid flow comprising a plurality of fiber elements with a second fluid flow comprising a plurality of first particles comprises co-forming the plurality of fiber elements with the plurality of first particles.

5. The method of claim 1, wherein the first fluid flow comprises a plurality of filaments mixed with a plurality of fibers.

6. The method of claim 1, wherein the second fluid flow comprises an air flow, the air flow comprising the plurality of first particles.

7. The method according to any one of claims 1 to 6, wherein the method further comprises the step of depositing a loosely woven layer on at least one surface of the fiber structure.

8. A fiber structure, said fiber structure being made by the method according to any one of claims 1 to 7.

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