Patterned non-woven substrates made from shaped surfaces having high and low porosity regions

Abstract

A method and system for producing a nonwoven substrate is disclosed. A forming surface or forming mesh for producing the substrate is also disclosed. The shaped surface includes a pattern of high porosity regions and low porosity regions. The low porosity region has a non-zero but low porosity. A wet fiber suspension is deposited onto the forming surface to form a nonwoven substrate having high basis weight and low basis weight regions. The width dimension of the low porosity zone is greater than the average fiber length of at least some types of fibers contained in the fiber composition to form a substrate having excellent properties, particularly in terms of fluid control properties.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on and claims priority from U.S. Provisional Patent Application Serial No. 63 / 396,677, filed on August 10, 2022, and U.S. Provisional Patent Application Serial No. 63 / 393,305, filed on July 29, 2022, both of which are incorporated herein by reference. Background Art

[0003] There are many different types of nonwoven materials, which are designed to have different functions. In many embodiments, nonwoven materials are designed to have liquid handling properties. These nonwoven materials can be used for absorbent articles or for producing wiping products, tissue products, etc.

[0004] Absorbent articles, also referred to as personal care products, such as diapers, diaper pants, training pants, adult incontinence products and feminine care products, can include multiple substrates. For example, diapers can include absorbent structures, nonwoven materials and films. Similarly, facial tissues, wipes and wipes can also include various substrates. Some substrates in the substrates in these products can include natural fibers and / or synthetic fibers. In some products, some substrates can also include different types of components, to provide additional functions to substrates and / or the final product itself.

[0005] For example, one such component that may be desired to be added to a substrate includes superabsorbent material (SAM). SAMs can be constructed in the form of particles or fibers and are typically used in substrates to increase absorbency. The absorbent system of personal care absorbent products such as diapers typically includes SAMs.

[0006] In many applications, liquid-absorbent nonwoven materials should not only have good liquid absorption properties, but also good fluid handling properties. In addition to having good fluid handling properties, nonwoven materials should also be flexible and made of as little material as possible. The present disclosure relates to further improvements in the formation of nonwoven materials so as to optimize fluid handling, improve fluid absorption properties, and / or improve at least one other physical property of the material. The present disclosure also relates to further improvements in systems and methods for producing nonwoven substrates. Summary of the invention

[0007] Generally speaking, the present disclosure relates to a method and system for producing nonwoven webs. By using a unique and improved forming surface, a nonwoven web having a high and low basis weight and / or thickness region is formed. By the method of the present disclosure, a nonwoven web having an elongated fluid control channel can be produced, which can be used in a fluid-absorbing product to quickly inhale and distribute fluid. The fluid control channel is also used as a point with greater flexibility, especially when manufacturing a substrate with a relatively high total basis weight. In one aspect, the low basis weight region can also be used to cut the nonwoven web in a more efficient manner, which can achieve faster conversion speeds and reduce the wear of the cutting equipment. As will be described in more detail below, the method of the present disclosure, the formed web manufactured according to the present disclosure, and the nonwoven product manufactured according to the present disclosure provide many different advantages and benefits.

[0008] In one embodiment, the present disclosure relates to a method for forming a nonwoven substrate. The method includes depositing a wet fiber suspension onto a forming surface. The fiber suspension includes at least a first type of fiber with an average fiber length. The forming surface includes a pattern of a porous first zone and a porous second zone. The porosity of the first zone is greater than the porosity of the second zone. For example, the porosity of the second zone may be at least about 50% smaller than the porosity of the first zone, such as at least about 60% smaller, such as at least about 70% smaller, such as at least about 80% smaller, such as at least about 90% smaller. According to the present disclosure, the width dimension of the second zone is greater than the average fiber length of the first type of fiber in distance. For example, in one aspect, the width dimension of the second zone is greater than all fibers contained in the wet suspension.

[0009] The fluid is discharged from the forming surface so as to form a continuous nonwoven substrate having regions of high basis weight corresponding to the first zones and regions of low basis weight corresponding to the second zones.

[0010] The porosity of the second zone is non-zero and can be significantly less than the porosity of the first zone. In one aspect, the second zone can have a porosity such that the second zone has an open area of ​​less than about 20%, such as less than about 10%, such as less than about 7%, such as less than about 5%, such as less than about 3%, and typically greater than about 1%, such as greater than about 2%.

[0011] In one embodiment, the fiber suspension may contain a plurality of different types of fibers. For example, the fiber suspension may include a first fiber type, a second fiber type, a third fiber type, a fourth fiber type, and so on. Each different fiber type may have a different average fiber length, and the width dimension of the second region may be greater than the longest average fiber length. In addition to fibers, the suspension may also contain other solid materials, including superabsorbent particles.

[0012] The width dimension of the second zone (the widest part of the second zone) may be greater than about 2 mm, such as greater than about 4 mm, such as greater than about 5 mm, such as greater than about 6 mm, such as greater than about 7 mm, and generally less than about 15 mm, such as less than about 10 mm, such as less than about 9 mm. The second zone may be present on the forming surface in any suitable pattern. In one embodiment, the second zone forms an elongated column on the forming surface, which may extend longitudinally, transversely, or diagonally in the longitudinal direction. In one embodiment, the column may be linear and may be parallel. Optionally, the column may have one curvature or multiple curvatures.

[0013] In one embodiment, the low porosity second zone does not substantially affect the topography of the forming surface. For example, the forming surface can be substantially flat, meaning that the height difference between the first and second zones does not exceed 0.5 mm, such as does not exceed about 0.1 mm. In one embodiment, the forming surface comprises a fabric formed by woven yarns. The second zone can be produced by applying an additive material to the fabric. For example, the additive material can be any suitable polymer material, such as a thermoplastic polymer. In one aspect, the additive material can be applied to the fabric using a three-dimensional printing device.

[0014] As mentioned above, the nonwoven substrate manufactured according to the present disclosure may include a low basis weight region and a high basis weight region. The basis weight in the low basis weight region may be less than about 50% or more than the basis weight in the high basis weight region, such as less than about 70%. Similarly, the thickness in the low basis weight region may be less than about 50% or more than the thickness in the high basis weight region, such as less than about 70%. The nonwoven substrate may be made of a fiber furnish, which may include any suitable fiber alone or in combination with other solid particles such as superabsorbent particles. In one aspect, the nonwoven substrate may be made of a separate pulp fiber, or may be made in combination with synthetic polymer fibers and / or superabsorbent particles. Alternatively, the nonwoven substrate may be made of a separate synthetic polymer fiber, or may be made in combination with superabsorbent particles. For example, the synthetic polymer fiber may include polyester fibers. In a specific aspect, the polyester fiber may have a fiber size of about 0.5 denier to about 15 deniers. In one embodiment, the nonwoven substrate may include superabsorbent particles combined with polymer synthetic fibers, binder fibers, and pulp fibers such as cork fibers. Binder fibers may include, for example, bicomponent fibers having a sheath polymer with a lower melting point.

[0015] For example, the nonwoven substrate manufactured according to the present disclosure can include an amount greater than about 5 wt %, such as an amount greater than about 10 wt %, such as an amount greater than about 15 wt %, and an amount less than about 50 wt %, such as an amount less than about 40 wt %, such as a binder fiber less than about 30 wt %. The nonwoven substrate can include an amount greater than about 3 wt %, such as an amount greater than about 5 wt %, such as an amount greater than about 7 wt %, such as an amount greater than about 10 wt %, and an amount less than about 75 wt %, such as an amount less than about 50 wt %, such as an amount less than about 35 wt %, such as a polymer synthetic fiber less than about 30 wt %.

[0016] In one aspect, the nonwoven substrate can include pulp fibers, particularly crosslinked pulp fibers. The crosslinked pulp fibers can be present in the nonwoven substrate in an amount greater than about 5% by weight, such as greater than about 10% by weight, such as greater than about 15% by weight, such as greater than about 20% by weight, and less than about 60% by weight, such as less than about 50% by weight.

[0017] When present, the superabsorbent material can be incorporated into the nonwoven substrate in an amount greater than about 10% by weight, such as greater than about 20% by weight, such as greater than about 30% by weight, and less than about 90% by weight, such as less than about 70% by weight, such as less than about 50% by weight, such as less than about 40% by weight. In one embodiment, the nonwoven substrate may include a multilayer web wherein the superabsorbent material is entirely contained in an intermediate layer between the top layer and the bottom layer.

[0018] Although the substrate manufactured according to the present disclosure can be formed by a wet-laid web process, in one embodiment, the nonwoven substrate is formed by a foamed fiber suspension. For example, when deposited on a forming surface, the foam can have a density of about 200 g / L to about 600 g / L, such as about 250 g / L to about 400 g / L. For example, the foamed suspension can include a foaming agent and water combined with the fibers. When deposited on a forming surface, the foamed suspension can include about 40 volume % to about 80 volume % of air.

[0019] The present disclosure also relates to a forming net for producing a nonwoven substrate. The forming net comprises a fabric formed by woven yarns. The fabric comprises a top forming surface, and the top forming surface comprises a pattern of a porous first zone and a porous second zone. The porosity of the first zone is greater than the porosity of the second zone. The porosity of the second zone can be at least 50% less than the porosity of the first zone, such as at least 60%, such as at least 70%, such as at least 80%, such as at least 90%, such as at least 95%. The second zone can have a width dimension greater than about 4mm, such as greater than about 5mm, such as greater than about 6mm, such as greater than about 7mm, and generally less than about 15mm, such as less than about 12mm, such as less than about 10mm, such as less than about 9mm. In one aspect, the second zone comprises a zone where additive material has been applied to the fabric.

[0020] The present disclosure also relates to a nonwoven substrate manufactured by the above method. The nonwoven substrate comprises a continuous nonwoven web having a first surface and a relative second surface. The nonwoven web may comprise a blend of fibers containing at least one of cellulose fibers, synthetic polymer fibers and superabsorbent particles. The nonwoven web may have an average basis weight of about 30 gsm to about 800 gsm. According to the present disclosure, a topographic pattern may be located on the first surface of the nonwoven web. The pattern may include a high basis weight region and a low basis weight region. The basis weight in the low basis weight region may be at least 50% less than the basis weight in the high basis weight region. The low basis weight region may have a width of at least 4 mm.

[0021] In one embodiment, the nonwoven material can be calendered to produce a flat planar sheet having high basis weight regions and low basis weight regions. Once the web is calendered, the high basis weight regions form high density regions, and the low basis weight regions form low density regions.

[0022] Other features and aspects of the disclosure are discussed in greater detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The disclosure that makes the present disclosure comprehensive and enabling is more particularly set forth in the remainder of the specification and with reference to the accompanying drawings, in which:

[0024] Figure 1 is one embodiment of a method and system that can be used to produce a nonwoven substrate according to the present disclosure;

[0025] Figure 2 is included in Figure 1 Details of the component feed systems in the illustrated process;

[0026] Figure 3 is a plan view of one embodiment of a forming surface according to the present disclosure;

[0027] Figure 4is a plan view of another embodiment of a shaped surface according to the present disclosure;

[0028] Figure 5 is a plan view of another embodiment of a shaped surface according to the present disclosure;

[0029] Figure 6 is a plan view of yet another embodiment of a shaped surface according to the present disclosure;

[0030] Figure 7 is a plan view of another embodiment of a shaped surface according to the present disclosure;

[0031] Figure 8 is a cross-sectional view of one embodiment of a nonwoven substrate made according to the present disclosure;

[0032] Fig. 9 is a plan view of another embodiment of a shaped surface according to the present disclosure; and

[0033] Fig.10 Is to use Fig. 9 A plan view of a nonwoven substrate made in accordance with the present disclosure showing a forming surface.

[0034] Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present disclosure.

[0035] definition

[0036] As used herein, the term "foam-formed product" means a product formed from a suspension comprising a mixture of solids, liquids, and dispersed gas bubbles.

[0037] As used herein, the term "foam-forming process" means a process for making a product involving a suspension comprising a mixture of solids, liquids, and dispersed gas bubbles.

[0038] As used herein, the term "foaming fluid" means any one or more known fluids that are compatible with the other components in the foam forming process. Suitable foaming fluids include, but are not limited to, water.

[0039] As used herein, the term "foam half-life" means the time that elapses until half of the initial foamed foam mass reverts to liquid water.

[0040] As used herein, the term "layer" refers to a structure providing a substrate region in the height direction of the substrate composed of similar components and structures.

[0041] As used herein, the term "nonwoven web" refers to a web having a structure of individual fibers or threads that are interlayered, but not in an identifiable manner (as in a knitted web).

[0042] As used herein, unless expressly stated otherwise, when used in connection with material composition, the terms "percent," "%," "weight percent," or "wt%" each refer to the amount of the component by weight as a percentage of the total amount, unless expressly stated otherwise.

[0043] The term "personal care absorbent article" refers herein to an article that is intended or adapted to be placed against or near the body of the wearer (i.e., adjacent to the body) to absorb and contain the various liquid, solid and semi-solid exudates discharged from the body. Examples include, but are not limited to, diapers, diaper pants, training pants, youth pant, swim pants, feminine hygiene products (including, but not limited to, menstrual pads or pants), incontinence products, medical garments, surgical pads and bandages, and the like.

[0044] As used herein, the term "superabsorbent material" refers to a water-swellable, water-insoluble organic or inorganic material, including superabsorbent polymers and superabsorbent polymer compositions that are capable of absorbing at least about 10 times their weight, or at least about 15 times their weight, or at least about 25 times their weight in an aqueous solution containing 0.9 weight percent sodium chloride under most favorable conditions.

[0045] As used herein, the term "machine direction" refers to the direction of travel of the forming surface upon which the fibers are deposited during the formation of the nonwoven web.

[0046] As used herein, the term "lateral direction" refers to a direction perpendicular to the longitudinal direction and the height direction defined above.

[0047] As used herein, the term "pulp" refers to fibers from natural sources such as woody and non-woody plants. Woody plants include, for example, deciduous and coniferous trees. Non-woody plants include, for example, cotton, flax, esparto grass, milkweed, straw, jute, hemp, and bagasse. Pulp fibers can include hardwood fibers, softwood fibers, and mixtures thereof.

[0048] As used herein, the term "average fiber length" refers to the average length of fibers, fiber bundles and / or fibrous materials determined by microscopic measurement. A sample of at least 20 randomly selected fibers is separated from a liquid suspension of fibers. The fibers are placed on a microscope slide that has been prepared to suspend the fibers in water. Coloring dyes are added to the suspended fibers to color the cellulose-containing fibers so that they can be distinguished or separated from synthetic fibers. The slide is placed under a Fisher Stereomaster II microscope--S19642 / S19643 series. 20 fibers in the sample are measured at 20X linear magnification using a 0-20 mil scale, and the average length, minimum and maximum lengths, and deviation or coefficient of variation are calculated. In some cases, the average fiber length will be calculated as the weighted average length of the fibers (e.g., fibers, fiber bundles, fibrous materials) as determined by a Kajaani fiber analyzer model FS-200, such as that available from Kajaani Oy Electronics, Kajaani, Finland. The samples are treated with an impregnation solution according to standard test procedures to ensure that no fiber bundles or fragments are present. Each sample is decomposed in hot water and diluted to approximately 0.001% suspension. When tested using the standard Kajaani fiber analysis test procedure, each test sample of approximately 50 ml to 100 ml is drawn from the diluted suspension. The weighted average fiber length can be an arithmetic mean, a length-weighted mean, or a weight-weighted mean, and can be represented by the following equation:

[0049]

[0050] in

[0051] k = maximum fiber length

[0052] x i =Fiber length

[0053] n i = Number of fibers of length xi

[0054] n = total number of fibers measured.

[0055] One characteristic of the average fiber length data measured by the Kajaani fiber analyzer is that it does not distinguish between different types of fibers. Therefore, the average length represents the average value based on the lengths of all different types (if any) of fibers in the sample.

[0056] As used herein, the term "staple fibers" refers to discontinuous fibers made from synthetic polymers or regenerated cellulose such as polypropylene, polyester, post-consumer recycled (PCR) fibers, polyester, nylon, viscose, rayon, etc., and those that are non-hydrophilic can be treated to be hydrophilic. Staple fibers can be cut fibers, etc. Staple fibers can have a cross-section that is round, bicomponent, multicomponent, shaped, hollow, etc. DETAILED DESCRIPTION

[0057] Those skilled in the art will appreciate that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the present disclosure.

[0058] The present disclosure relates to methods and systems that can produce nonwoven substrates.While the present disclosure provides examples of substrates made by foam forming, it is contemplated that the methods and apparatus described herein can be used to benefit wet-laid and / or air-laid manufacturing processes.

[0059] Each example is given by way of illustration and is not meant to be limiting. For example, a feature illustrated or described as part of one embodiment or figure may be used in another embodiment or figure to produce yet another embodiment. It is intended that the present disclosure encompasses such modifications and variations.

[0060] When introducing elements of the present disclosure or its preferred embodiments, the articles "a", "an", "the" and "said" are intended to indicate the presence of one or more of the elements. The words "comprise", "comprising" and "having" are intended to be inclusive, meaning that there may be additional elements outside the listed elements. As used herein, the terms "first", "second", "third", etc. do not specify a specified order, but are used as a means to distinguish different events when referring to various features in the present disclosure. Without departing from the spirit and scope of the present disclosure, many modifications and variations may be made to the present disclosure. Therefore, the exemplary embodiments described herein should not be used to limit the scope of the present invention.

[0061] Generally speaking, the present disclosure relates to a method and system for producing a nonwoven substrate. The present disclosure also relates to a unique forming web for producing a substrate. The nonwoven substrate can be a single layer, or can be multilayer. According to the present disclosure, the nonwoven substrate is formed with a pattern of high basis weight areas and low basis weight areas, which can provide many advantages and benefits. The nonwoven substrate of the present disclosure can be used for a variety of end-use applications. The pattern of high basis weight areas and low basis weight areas can provide significantly improved functionality customized for specific applications.

[0062] The nonwoven substrate can be used in many different types of applications. For example, the nonwoven substrate can be used to form a wiping product. Alternatively, the nonwoven substrate can contain superabsorbent material and be used to form an absorbent core in an absorbent article. In this embodiment, the absorbent article can include a liquid-permeable liner, a liquid-impermeable outer cover, and an absorbent core between the liner and the outer cover manufactured according to the present disclosure.

[0063] For example, in one aspect, low basis weight regions are surrounded by higher basis weight regions and form fluid control channels that can be used to quickly absorb and distribute fluids, which can provide advantages when incorporated into absorbent articles, wiping products, etc. Lower basis weight regions can also be used as points with greater flexibility to make high basis weight regions consistent with adjacent surfaces. In particular, low basis weight regions produce softer and more consistent-shaped substrates that appear as thinner materials, especially relative to substrates made entirely from high basis weight regions. Alternatively, high basis weight regions can be surrounded by low basis weight regions.

[0064] In addition to the above, the low basis weight areas can be formed with relatively wide portions, which can significantly improve the breathability of the material. When included in an absorbent article, the substrate made according to the present disclosure can create an optimal microclimate by allowing better air exchange through the low basis weight areas. When incorporated into diapers, adult incontinence products, etc., the pattern of high basis weight areas and low basis weight areas can be designed to collect and keep away body feces and other body fluids to protect the skin and provide a garment that promotes better health.

[0065] Nonwoven substrates made according to the present disclosure may also provide enhanced comfort. For example, a pattern of high basis weight areas and low basis weight areas may provide a "cushion-like" feel to the user. The pattern may also be designed for visual appeal or as a signal to the user to highlight some other benefit of the product.

[0066] On the other hand, nonwoven substrate can be made and wound into rolls according to the disclosure. Then the roll can be sent into the conversion process to produce various products, including absorbent articles or wiping products. Low basis weight areas can be designed to be used for cutting nonwoven materials into strips or single tracks or channels. Cutting along the low basis weight areas can achieve faster conversion speeds and a reduction in cutting equipment wear.

[0067] According to the present disclosure, the nonwoven substrate manufactured according to the present disclosure can be formed by a wet suspension of fibers and other solid materials. The substrate can be formed in a wet web forming process or a foam forming process. The wet suspension of fibers and other solid materials is deposited on a specially designed patterned forming net. The patterned net has a low porosity area and a high porosity area. The low porosity area has some porosities (but not non-zero porosity) much lower than the high porosity area. According to the present disclosure, the width size of the low porosity area is greater than the average length of at least one of the fiber types in the fiber furnish for forming the wet suspension. However, the porosity in the low porosity area can be controlled to prevent the formation of holes in the substrate formed on the forming surface. In this regard, the forming net is constructed and the process is controlled to produce a continuous substrate. For example, the nonwoven substrate formed on the forming surface includes a high basis weight area and a low basis weight area corresponding to the pattern of the high porosity area and the low porosity area, respectively.

[0068] Alternatively, the process can be designed to produce a nonwoven substrate having holes located at key and desired locations. The hole can be located in a high basis weight region or a low basis weight region. For example, the hole can be used for better fluid control, perhaps directing the fluid into an adjacent layer. In one embodiment, the hole can be formed by forming a region with zero porosity on a forming surface.

[0069] Partly due to the width size of the low porosity zone, a nonwoven substrate with significant basis weight difference and / or thickness can be produced on the forming surface, which can produce products with many different enhanced properties as described above. For example, the basis weight in the low basis weight region can be less than about 50% or more. In various embodiments, for example, the basis weight in the low basis weight region can be less than about 60% or more, such as about 70% or more, such as about 80% or more, such as about 90% or more. Similarly, the thickness in the low basis weight region can be less than about 50% or more, such as about 60% or more, such as about 70% or more, such as about 80% or more, such as about 90% or more.

[0070] According to specific application, high basis weight area can have any suitable basis weight and thickness.When forming some wiping products or absorbent structures, higher basis weight area can have greater than about 50gsm, such as greater than about 80gsm, such as greater than about 100gsm, such as greater than about 120gsm, such as greater than about 140gsm, and less than about 800gsm, such as less than about 600gsm basis weight.The thickness of high basis weight area can be greater than about 0.5mm usually, such as greater than about 1mm, such as greater than about 1.5mm, such as greater than about 2mm, such as greater than about 2.5mm, such as greater than about 3mm, such as greater than about 3.5mm, such as greater than about 4mm, and less than about 50mm, such as less than about 30mm, such as less than about 20mm.

[0071] Alternatively, the nonwoven substrate can be calendered so that the substrate has a uniform thickness, but includes high-density regions and low-density regions. The density of the high basis weight region can be less than about 50% or more of the density of the low basis weight region, such as about 60% or more, such as about 70% or more, such as about 80% or more, such as about 90% or more.

[0072] In the past, patterned forming nets that may include low drainage areas or topographic structures have been proposed. For example, U.S. Pat. No. 10,920,374 discloses a three-dimensional papermaking belt, and WO96 / 35018 discloses a decorative forming fabric. Both references are incorporated herein by reference. Although both references provide various improvements in the art, the forming net of the present disclosure provides many advantages and benefits over the forming surfaces disclosed in the references. In addition, WO96 / 35018 specifically teaches that the width of the lines comprising the decorative areas and low drainage areas of the forming surface must have such a width that about 50% or more of the fibers in the furnish have a fiber length greater than the line width, otherwise a discontinuous network containing undesirable holes will be formed.

[0073] However, as described in more detail below, in one aspect, the forming surface of the present disclosure may include a low porosity zone, and the width of the low porosity zone may be greater than the fiber length of the longest fiber in the furnish. It has been found that this design not only provides many advantages and benefits, but also can be incorporated into the process for forming a nonwoven substrate without forming a hole. In addition, when using a foam forming process to manufacture a nonwoven substrate according to the present disclosure, many different fibers, fiber sizes and materials can be processed separately or together. Therefore, a nonwoven substrate with unique characteristics, basis weight, thickness, etc. can be manufactured according to the present disclosure.

[0074] The nonwoven substrate manufactured according to the present disclosure is formed by a wet suspension of fiber and optional other solid materials. The process for forming the nonwoven substrate can be a wet-laid web process, an air-formed process or a foam-formed process. The nonwoven substrate can be a single-layer material, or can be a multilayer material.

[0075] refer to Figure 1 , for exemplary purposes only, shows one embodiment of a method that can be used to form a nonwoven substrate according to the present disclosure. Figure 1 The illustrated method and system may be a wet-laid process. However, when a foam forming process is used, various benefits and advantages may be obtained. Therefore, Figure 1 The illustrated system and method will be described in more detail below as a foam forming process.

[0076] refer to Figure 1 and Figure 2 In one embodiment, the present disclosure is directed to a method and apparatus 10 that can form a substrate 12 . Figure 1 A schematic diagram of an exemplary apparatus 10 that can be used as part of a foam forming process to manufacture a substrate 12 as a foam-formed product is provided. The apparatus 10 may include a first tank 14 configured to hold a first fluid supply 16. In some embodiments, the first fluid supply 16 may be a foam. The first fluid supply 16 may include a fluid provided by a fluid supply 18. In some embodiments, the first fluid supply 16 may include a plurality of fibers provided by a supply of fibers 20, however, in other embodiments, the first fluid supply 16 may not have a plurality of fibers. The first fluid supply 16 may also include a surfactant provided by a surfactant supply 22. In some embodiments, the first tank 14 may include a mixer 24, which will be discussed in more detail below. The mixer 24 may mix (e.g., agitate) the first fluid supply 16 to mix the fluid, the fibers (if present), and the surfactant with air or some other gas to produce a foam. The mixer 24 may also mix the foam with the fibers (if present) to produce a foam suspension of the fibers, wherein the foam holds and separates the fibers to facilitate the distribution of the fibers within the foam (e.g., as an artifact of the mixing process in the first tank 14). Uniform fiber distribution can promote desirable substrate properties including, for example, strength and quality visual appearance.

[0077] The apparatus 10 may also optionally include a second tank 26 configured to hold a second fluid supply 28. In some embodiments, the second fluid supply 28 may be a foam. The second fluid supply 28 may include a fluid provided by a supply of fluid 30 and a surfactant provided by a supply of surfactant 32. In some embodiments, the second fluid supply 28 may include a plurality of fibers in addition to or in lieu of the fibers present in the first fluid supply 16. In some embodiments, the second tank 26 may include a mixer 34. The mixer 34 may mix the second fluid supply 28 to mix the fluid and the surfactant with air or some other gas to produce a foam.

[0078] For either or both of the first tank 14 and the second tank 26, the first fluid supply 16 or the second fluid supply 28 can be activated to form a foam. In some embodiments, the foaming fluid and other components are activated to form a porous foam having an air content greater than about 50% by volume and ideally an air content greater than about 60% by volume. In some aspects, the highly expanded foam is formed to have an air content between about 60% and about 95%, and in other aspects, between about 65% and about 85%. In some embodiments, the foam can be activated to introduce a foam so that the expansion ratio (the volume of air to other components in the expanded stable foam) is greater than 1:1, and in some embodiments, the ratio of air: other components can be between about 1.1:1 and about 20:1, or between about 1.2:1 and about 15:1, or between about 1.5:1 and about 10:1, or even between about 2:1 and about 5:1.

[0079] Foam can be produced by one or more means known in the art. Examples of suitable methods include, but are not limited to, such as vigorous mechanical stirring by mixers 24, 34, injection of compressed air, and the like. Mixing components by using a high shear high-speed mixer is particularly suitable for forming desired highly porous foams. Various high shear mixers are known in the art and are considered to be suitable for the present disclosure. High shear mixers typically use a tank that holds a foam precursor and / or one or more pipes through which the foam precursor is guided. High shear mixers can use a series of screens and / or rotors to process the precursor and cause vigorous mixing of the components and air. In a particular embodiment, a first tank 14 and / or a second tank 26 are provided, wherein there are one or more rotors or impellers and associated stators. The rotors or impellers rotate at high speed to cause flow and shear. For example, air can be introduced into the tank at various positions, or simply inhaled by the action of mixers 24, 34. While the specific mixer design may affect the speed necessary to achieve the desired mixing and shearing, in certain embodiments, suitable rotor speeds may be greater than about 500 rpm, and, for example, between about 1000 rpm and about 6000 rpm or between about 2000 rpm and about 4000 rpm. In certain embodiments, relative to rotor-based high shear mixers, the mixers 24, 34 may be run with the foam until the vortex in the foam disappears or a sufficient volume increase is achieved.

[0080] In addition, it should be noted that for the first tank 14 and / or the second tank 26, the foaming process can be completed in a single foam generation step or in a continuous foam generation step. For example, in one embodiment, all components of the first fluid supply 16 in the first tank 14 (e.g., the supply of fluid 18, fiber 20 and surfactant 22) can be mixed together to form a slurry, and the foam is formed by the slurry. Alternatively, one or more separate components can be added to the foaming fluid to form an initial mixture (e.g., dispersion or foam), and then the remaining components can be added to the initial foamed slurry, and then all components are acted to form the final foam. In this regard, the fluid 18 and the surfactant 22 can be mixed and acted to form the initial foam before any solids are added. If desired, the fiber can then be added to the water / surfactant foam, which then further acts to form the final foam. Alternatively, the fluid 18 and fibers 20 (such as high density cellulose pulp) can be vigorously mixed at a higher consistency to form an initial dispersion, after which a foaming surfactant, additional water, and other components (such as synthetic fibers) are added to form a second mixture, which is then mixed and acted to form a foam.

[0081] The foam density of the foam forming the first fluid supply 16 in the first tank 14 and / or the foam forming the second fluid supply 28 in the second tank 26 may vary depending on the specific application and various factors (such as the fiber raw material used). In some embodiments, for example, the foam density of the foam may be greater than about 100 g / L, such as greater than about 250 g / L, such as greater than about 300 g / L. The foam density is generally less than about 800 g / L, such as less than about 500 g / L, such as less than about 400 g / L, such as less than about 350 g / L. In some embodiments, for example, a lower density foam is used with a foam density generally less than about 350 g / L, such as less than about 340 g / L, such as less than about 330 g / L.

[0082] In some embodiments, the apparatus 10 may also include a first pump 36 and a second pump 38. The first pump 36 may be in fluid communication with the first fluid supply 16 and may be configured to pump the first fluid supply 16 to transfer the first fluid supply 16. The second pump 38 may be in fluid communication with the second fluid supply 28 and may be configured to pump the second fluid supply 28 to transfer the second fluid supply 28. In some embodiments, the first pump 36 and / or the second pump 38 may be a screw pump or a centrifugal pump, however, it is contemplated that other suitable types of pumps may be used. In addition, as discussed further below, in some embodiments, the apparatus may be provided with a single pump that can pump a single fluid supply into the first fluid supply 16 and the second fluid supply 28.

[0083] like Figure 1 and Figure 2 , the apparatus 10 may also optionally include a component feed system 40. For example, the component feed system 40 may be used to feed particulate material (such as superabsorbent particles) into the fiber furnish. However, when the substrate is formed solely of fibers, the component feed system 40 is not required, including the use of the second fluid supply 28. When present, the component feed system 40 may include a component supply area 42 for receiving a supply of a component 44, such as Figure 2 4. The component feed system 40 may further include an outlet conduit 46. The cross-sectional shape of the outlet conduit 46 may be circular, or may be configured in a rectangular form to form a slot. The component feed system 40 may further include a hopper 48. The hopper 48 may be coupled to the component supply area 42 and may be used to refill the supply of the component 44 to the component supply area 42.

[0084] In some embodiments, the component feed system 40 may include a solid volumetric pump. Some examples of solid volumetric pumps that can be used herein may include systems utilizing screws / auger, belts, vibrating trays, turntables, or other known systems for handling and discharging the supply of component 44. Other types of feeders can be used for the component feed system 40, such as batching feeders, such as those manufactured by Christy Machine & Conveyor, Fremont, Ohio. In some embodiments, the component feed system 40 may also be configured as a conveyor system.

[0085] The component feed system 40 may also include a fluid control system 50. The fluid control system 50 may be configured to control the entrainment of gas into the fluid supply in which the supply of component 44 is placed. In some embodiments, the fluid control system 50 may include a housing 52. The housing 52 may form a pressurized sealed volume around the component feed system 40. In other embodiments, the fluid control system 50 may be formed as an integral part of the structural component feed system 40 itself, such that a separate housing 52 surrounding the component feed system 40 may not be required. Figure 1 and Figure 2 As shown, in some embodiments, the fluid control system 50 may further include a bleed hole 54 .

[0086] The supply of component 44 can be in the form of particles and / or fibers. In one embodiment described herein, the supply of component 44 can be a superabsorbent material (SAM) in the form of particles. In some embodiments, SAM can be in the form of fibers. Of course, as further described below, other types of components may also be considered for use in the apparatus 10 and method described herein. The component feed system 40 as described herein may be particularly beneficial for the supply of component 44 that is most suitable for maintaining in a dry environment, wherein minimal exposure to the fluid or foam used in the apparatus 10 and method described herein.

[0087] In some embodiments, the apparatus 10 and methods described herein may include a first mixing joint 56 and a second mixing joint 58. In a preferred embodiment, the first mixing joint 56 may be an ejector. The first mixing joint 56 may be in fluid communication with the outlet conduit 46 of the component feed system 40 and in fluid communication with the second fluid supply 28. The first mixing joint 56 may be configured as a coaxial ejector.

[0088] The first mixing joint 56 may mix the supply of component 44 from the component feed system 40 with the second fluid supply 28 .

[0089] Reference again Figure 1 , in some embodiments, the apparatus 10 may include a second mixing joint 58. The second mixing joint 58 may provide functionality to mix the second fluid supply 28, including components from the supply of component 44, with the first fluid supply 16. When the second fluid supply 28, including components from the supply of component 44, exits the discharge port 64 of the first mixing joint 56, it may be transferred to the second mixing joint 58. The first fluid supply 16 may be delivered to the second mixing joint 58 by the first pump 36. The second mixing joint 58 may mix the first fluid supply 16 and any of its components (e.g., fluid 18, fiber 20, surfactant 22) with the second fluid supply 28 and any of its components (e.g., fluid 30, surfactant 32) and components from the supply of component 44 to provide a resulting slurry 76. The resulting slurry 76 may be transferred from the second mixing joint 58 to the headbox 80 through the discharge port 78 of the second mixing joint 58.

[0090] A headbox 80 may be provided to transfer the resulting slurry 76 to form the substrate 12. The headbox 80 may have a longitudinal direction 81 and a transverse direction 83. The longitudinal direction 81 is the direction in which the resulting slurry 76 is transferred through the headbox 80.

[0091] The wet slurry 76 is deposited from the headbox 80 onto a forming surface 94 manufactured according to the present disclosure. As will be described in more detail below, the forming surface 94 includes a combination of at least one high porosity region and at least one low porosity region for producing a nonwoven substrate having at least one high basis weight region and at least one low basis weight region.

[0092] exist Figure 1 In the illustrated embodiment, the forming surface 94 is shown to be in a horizontal position. In an alternative embodiment, the forming surface 94 can be placed at an angle to the headbox 80 so that the slurry 76 moves in an upward motion once deposited on the forming surface 94. For example, the forming surface 94 can be positioned at an angle greater than about 5°, such as greater than about 10°, such as greater than about 15°, and generally less than about 50°, such as less than about 40°, such as less than about 30°, such as less than about 20°, to the horizontal plane. The headbox 80 can be designed to produce a single-layer substrate, or can be used to produce a multi-layer substrate. The substrate 12 can be manufactured according to the present disclosure, for example, with two layers, three layers, four layers, five layers, etc. If desired, each layer can have a different fiber furnish.

[0093] Once the slurry 76 is deposited on the forming surface 94, fluid is removed from the suspension to form a nonwoven substrate. In this regard, the forming surface 94 can be a porous porous sheet and can be made at least in part from a woven belt or a screen. The system can also include a dewatering system 96 that can be configured to remove liquid from the slurry 76 by the forming surface 94. For example, the dewatering system 96 can provide a vacuum to the slurry 76 to extract fluid from the slurry for forming a consolidated substrate 12.

[0094] like Figure 1 As shown, the process may also include a drying system 98. The drying system 98 may be configured to dry the newly formed nonwoven substrate 12. Generally speaking, any suitable dryer may be incorporated into the drying system 98. For example, the drying system 98 may be a through-air dryer, one or a series of heating cylinders, an oven, etc. The process may also include a winding system 99, which may be configured to wind the substrate 12 into a roll after drying.

[0095] Reference now Figure 3-Figure 7 , showing various embodiments of a shaped surface 94 made according to the present disclosure. Figure 3 , for example, illustrates a forming surface 94 that includes a pattern of porous first regions 102 and porous second regions 104. The porosity of the first regions 102 is greater than the porosity of the second regions 104. Figure 3 100 is also shown in the longitudinal direction, indicating the movement of the forming surface 94 for conveying the nonwoven substrate 12 downstream. Therefore, the porous second zone 104 extends in the transverse direction. However, in other embodiments, the porous second zone 104 can extend in the longitudinal direction or can extend diagonally along the longitudinal direction.

[0096] According to the present disclosure, the porous second zone 104 has a non-zero porosity, but has a porosity much smaller than the porosity of the first zone 102. For example, the porosity of the second zone 104 can be at least about 50% smaller than the porosity of the first zone 102, such as at least about 60% smaller, such as at least about 70% smaller, such as at least about 80% smaller, such as at least about 90% smaller, such as at least about 95% smaller, and at most about 99.5% smaller. Therefore, when the slurry 76 is deposited on the forming surface 94 and dewatered, the fibers and / or particulate materials contained in the slurry are preferentially accumulated on the forming surface 94 where the higher porosity first zone 102 is located. The porosity and process of the second zone 104 are controlled so that at least some solid matter is also accumulated on the second zone 104 for the production of continuous sheets. In this way, a nonwoven substrate 12 having a pattern of high basis weight regions and low basis weight regions is formed, wherein the low basis weight regions have a significantly reduced basis weight relative to the high basis weight regions.

[0097] The basis weight of high basis weight area and the basis weight of low basis weight area can change according to specific application and process conditions.High basis weight area can usually have greater than about 30gsm, such as greater than about 50gsm, such as greater than about 80gsm, such as greater than about 100gsm, such as greater than about 120gsm, such as greater than about 150gsm, such as greater than about 180gsm, such as greater than about 200gsm, such as greater than about 250gsm, such as greater than about 270gsm, such as greater than about 300gsm, such as greater than about 320gsm, such as greater than about 350gsm, such as greater than about 370gsm, such as greater than about 400gsm, such as greater than about 420gsm, such as greater than about 450gsm, such as greater than about 470gsm, such as greater than about 500gsm. The basis weight in high basis weight region is usually less than about 800gsm, such as less than about 750gsm, such as less than about 700gsm, such as less than about 650gsm, such as less than about 600gsm, such as less than about 550gsm, such as less than about 500gsm, such as less than about 450gsm, such as less than about 400gsm, such as less than about 350gsm, such as less than about 300gsm, such as less than about 250gsm, such as less than about 200gsm, such as less than about 150gsm, such as less than about 100gsm, such as less than about 80gsm.As mentioned above, the basis weight in low basis weight region can be usually less than about 40% to about 99% any value between the basis weight in high basis weight region, including all 1% increments therebetween.Nonwoven substrate can also have the average basis weight that the basis weight in high basis weight region and low basis weight region is averaged. The nonwoven substrate may have an average basis weight of about 30 gsm to about 800 gsm, such as about 40 gsm to about 600 gsm.

[0098] exist Figure 3In the illustrated embodiment, the low-porous second region 104 is formed into elongated columns on the forming surface 94. Figure 3 In the embodiment, the elongated pillars 104 are linear and parallel to each other. However, in other embodiments, the pillars 104 can be curved and / or include multiple curvatures along their length.

[0099] According to the present disclosure, porous second zone 104 may have a width that is generally longer than any fiber contained in slurry or suspension 76. For example, slurry 76 may include one fiber type or multiple different types of fibers. Each fiber type may have an average fiber length. The width of second zone 104 may be greater than the average fiber length of at least one of the fiber types, and in one embodiment, greater than the longest type of fiber contained in the slurry. In this way, significant basis weight differences can be formed in the nonwoven substrate, which produces many beneficial properties and advantages.

[0100] For example, the width of the second zone 104 may generally be greater than about 0.5 mm, such as greater than about 1 mm, such as greater than about 1.5 mm, such as greater than about 2 mm, such as greater than about 2.5 mm, such as greater than about 3 mm, such as greater than about 4 mm, such as greater than about 5 mm, such as greater than about 6 mm, such as greater than about 7 mm, such as greater than about 8 mm, such as greater than about 9 mm. The width of the second zone 104 is generally less than about 15 mm, such as less than about 12 mm, such as less than about 11 mm, such as less than about 10 mm, such as less than about 9 mm. The width of the second zone 104 as described above generally refers to that at least one area of ​​the second zone 104 has the above-mentioned width dimension. Figure 3 In the illustrated embodiment, the second region 104 has a uniform width. However, in other embodiments, the width may vary as long as at least a portion of the width is greater than the average fiber length of at least one of the fiber types. In one embodiment, the width of the second region 104 is at least 10% greater than the length of the second region 104 of the longest fiber length. For example, the width of the second region 104 may be at least about 20% greater than the longest fiber length, such as at least about 30% greater, such as at least about 40% greater, such as at least about 50% greater, such as at least about 60% greater, such as at least about 70% greater, such as at least about 80% greater.

[0101] The porous sheet or forming mesh that creates the forming surface 94 can be manufactured in any suitable manner. For example, in one embodiment, the forming surface 94 can be formed by woven yarns that form a fabric. In order to form the low-porosity second zone 104, the density of the fabric can be increased. The yarn can be made of polymer fibers, metal fibers, or a combination thereof.

[0102] Alternatively, the second regions 104 can be created by depositing a material on the forming surface 94 that serves to impede flow through the forming surface while still creating low porosity areas. In one aspect, for example, a polymer material or an additive material, such as a thermoplastic or thermosetting polymer, can be applied to the fabric to form the second regions 104. The polymer material can be applied to the fabric in a manner that does not completely impede flow through the fabric. Alternatively, a polymer can be applied to the fabric and holes, such as pinholes, can then be formed in the polymer layer to form the second regions 104.

[0103] In one particular embodiment, the second region 104 is created by applying the additive material to the fabric using a three-dimensional printer. The 3-D printer can apply the additive material in different layers to the fabric until the desired pattern is created and until the second region 104 has the desired porosity. The additive material can be applied to the woven fabric, thereby impregnating the fabric, embedding itself into the voids of the fabric.

[0104] For example, in one embodiment, the additive material is melted and applied to the fabric by a three-dimensional printer. The molten polymer flows partially or completely around the individual yarns that make up the fabric, thereby ensuring a strong mechanical bond. The second layer is then applied to the fabric to achieve the desired design dimensions. The use of a 3-D printer can provide various advantages and benefits. For example, a 3-D printer can apply the additive material as large discrete elements or small elements to create complex designs. It is particularly advantageous that the additive material can be applied to the fabric so that the second zone 104 is durable and can withstand processing conditions and the movement of the forming surface around rollers as a conveyor.

[0105] The porosity of the second zone 104 may vary depending on the specific application and the desired results. Generally speaking, the second zone 104 may be formed so that the second zone has an open area of ​​less than about 15% relative to the total surface area of ​​the second zone. For example, the open area of ​​the second zone 104 may be less than about 12%, such as less than about 10%, such as less than about 8%, such as less than about 6%, such as less than about 5%, such as less than about 4%, such as less than about 3%. The open area of ​​the second zone 104 is generally greater than about 0.5%, such as greater than about 1%, such as greater than about 2%.

[0106] The open areas on the second zone 104 may consist of channels of any suitable size and shape through the forming surface 94. For example, the open areas may consist of micropores densely packed in the second zone 104. Alternatively, the open areas may consist of larger pinholes spaced apart along the second zone 104. The size and pattern of the holes extending through the second zone 104 may be controlled and optimized for a particular application.

[0107] In one embodiment, a porous second zone 104 can be formed on a forming surface 94 without generating raised areas on the forming surface. In fact, in one embodiment, if the forming surface 94 forms a substantially flat surface, so that the second zone 104 is less than about 0.5 mm above the surface of the first zone 102, such as less than about 0.3 mm, such as less than about 0.1 mm, such as less than about 0.05 mm, various advantages and benefits can be obtained. For example, having raised features on the forming surface 94 may cause additional challenges to processing nonwoven substrates. In fact, it is found that raised areas are not required to produce substrates with high and low basis weight areas.

[0108] like Figure 3 As shown, the second zones 104 are spaced apart along the longitudinal direction 100 of the forming surface 94. The spacing between the second zones 104 can vary depending on the specific application and the desired results. For example, in one embodiment, the spacing between the second zones 104 (measured from the edge of one second zone to the adjacent edge of the second zone) is greater than about 1 mm, such as greater than about 2 mm, such as greater than about 3 mm, such as greater than about 5 mm, such as greater than about 6 mm, such as greater than about 7 mm, such as greater than about 8 mm, such as greater than about 9 mm, such as greater than about 10 mm, such as greater than about 11 mm, such as greater than about 12 mm, such as greater than about 13 mm, such as greater than about 14 mm, such as greater than about 15 mm, such as greater than about 20 mm, such as greater than about 26 mm, About 30mm, such as greater than about 40mm, such as greater than about 50mm, such as greater than about 60mm, such as greater than about 70mm, such as greater than about 80mm, and typically less than about 500mm, such as less than about 200mm, such as less than about 100mm, such as less than about 70mm, such as less than about 50mm, such as less than about 30mm, such as less than about 20mm, such as less than about 18mm, such as less than about 16mm, such as less than about 14mm, such as less than about 12mm, such as less than about 10mm, such as less than about 5mm.

[0109] like Figure 3 As shown, once the slurry or suspension of fibers and / or other solid materials is deposited onto the forming surface 94, the fluid is drained so that a nonwoven substrate 12 is formed that includes high basis weight and low basis weight regions corresponding to the porous first region 102 and the porous second region 104, respectively. For example, referring to Figure 8 , exemplifies the Figure 3 94 is a cross-section of a nonwoven substrate 12 manufactured on a forming surface 94 as shown. As shown, the nonwoven substrate 12 includes high basis weight regions 106 separating low basis weight regions 108. On the forming surface 94, the high basis weight regions 106 are formed where the first zones 102 are located, and the low basis weight regions 108 are formed where the second zones 104 are located. Figure 8As shown, the low basis weight regions form fluid control channels in the substrate, which produces many advantages and benefits. For example, the fluid control channels 108 can quickly absorb and distribute fluids that come into contact with the substrate 12. The low basis weight channels 108 can also greatly increase the flexibility of the substrate 12, making it easier for the substrate 12 to conform to adjacent surfaces, such as the user's body. The low basis weight regions 108 improve the feel of the substrate 12 and greatly enhance the drapability of the substrate.

[0110] When being incorporated in absorbent article, low basis weight area 108 can improve breathability, and allows better air exchange when the user wears absorbent article.When being incorporated in incontinence products such as diapers, low basis weight area can be used for collecting body fluids such as loose stools, and removes body fluids from the skin of the user.Therefore, when being incorporated in absorbent article, nonwoven substrate 12 can greatly enhance skin health.On the other hand, high basis weight area 106 is very suitable for absorbing a large amount of fluids, and can also provide similar cushion feeling for substrate.In addition, substrate 12 can have overall visual appeal, and this depends on the pattern of low basis weight area 108.

[0111] refer to Figure 4-Figure 7 , shows additional embodiments of shaped surfaces that can be constructed according to the present disclosure. Similar reference numerals are used to indicate similar elements. For example, referring to Figure 4 , the forming surface 94 includes a highly porous first region 102 surrounding a less porous second region 104. In this embodiment, the second region 104 has an X-like shape. For example, the second region 104 can be in the shape of any suitable symbol, letter, number, geometric shape, etc.

[0112] refer to Figure 5 , the second regions 104 are in the shape of curves or wavy lines that form discrete high-porosity first regions 102. For example, the high-porosity first regions 102 have an eye-like shape. In other embodiments, the low-porosity second regions 104 may not intersect, so that the high-porosity first regions 102 do not form a separate unit, but extend along the length of the forming surface 94.

[0113] refer to Figure 6 In this embodiment, the low-porous second area 104 is in the shape of a hexagon, which forms a honeycomb pattern on the forming surface 94. The high-porous first area 102 forms a separate unit in each hexagon. In addition to having a hexagonal shape, the low-porous second area 104 can be circular, in the shape of a triangle, square, rectangle, pentagon, octagon, etc. In this way, the low-porous area forms a grid-like pattern in the nonwoven substrate. Alternatively, the high-porous area can form a grid-like pattern of units surrounding the low-porous area.

[0114] See also Figure 7, shows another embodiment of a forming surface 94 made according to the present disclosure. In this embodiment, the low-porous second region 104 forms discrete shapes within the high-porous first region 102. In this embodiment, the discrete shapes 104 are in the form of circles. Alternatively, the low-porous second region 104 can have any suitable shape, such as an oval, square, triangle, or random shape. In yet another embodiment, the pattern can be reversed so that the high-porous second region forms discrete shapes within the low-porous first region.

[0115] For example, the circle 104 may have a diameter greater than about 2 mm, such as greater than about 4 mm, such as greater than about 6 mm, such as greater than about 8 mm, such as greater than about 10 mm, and less than about 25 mm, such as less than about 20 mm, such as less than about 15 mm. In one embodiment, the circle spacing may be greater than about 3 mm, such as greater than about 5 mm, such as greater than about 7 mm, such as greater than about 10 mm, and less than about 30 mm, such as less than about 28 mm, such as less than about 26 mm.

[0116] refer to Fig. 9 and Fig.10 , showing the forming surface 94 ( Fig. 9 ) is another embodiment, which is formed on the forming surface 94 of the nonwoven substrate 12 ( Fig.10 ) are combined. Fig. 9 As shown, the forming surface 94 includes high porosity or first areas 102 separated by low porosity second areas 104. In this embodiment, the low porosity areas 104 are in the form of discontinuous strips or parallel lines, meaning that there is a pattern of high porosity areas within the low porosity areas 104. In this embodiment, for example, there are high porosity discrete shapes or points within the low porosity areas 104. In this manner, it is believed that the low porosity areas 104 can have a greater width while still producing a nonwoven substrate having continuity and integrity.

[0117] For example, using Fig. 9 The nonwoven web 12 produced by the forming surface 94 shown is exemplified in Fig.10 In. Fig.10 As shown, nonwoven substrate 12 includes high basis weight regions 106 separated by low basis weight regions 108. Low basis weight regions 108 are in the form of discontinuous strips, which include tuft patterns formed as strips in the form of discrete shapes. In one aspect, low basis weight regions 108 or strips may have a width greater than about 5 mm, such as greater than about 8 mm, such as greater than about 10 mm, such as greater than about 12 mm, and less than about 40 mm, such as less than about 30 mm, such as less than about 20 mm, such as less than about 18 mm.

[0118] like Fig.10The low basis weight region 108 shown is particularly suitable for use as a slit channel for cutting the nonwoven substrate 94. For example, the low basis weight region 108 is easier to slit or cut, thereby being able to achieve faster conversion speeds during the cutting process and reducing the wear of the cutting equipment. For example, in one embodiment, the low basis weight region 108 can form a plurality of channels for cutting the nonwoven substrate 12 into a plurality of strips or sheets. The tuft pattern present in the low basis weight region 108 provides a certain strength or integrity for the low basis weight region while allowing a wider channel for cutting.

[0119] Generally speaking, the pattern of the low-porous second zone 104 occupies less than about 90% of the surface area of ​​the forming surface 94. For example, the low-porous second zone 104 may occupy less than about 50%, such as less than about 40%, such as less than about 30%, such as less than about 20% of the surface area of ​​the forming surface. The low-porous second zone typically occupies more than about 5%, such as more than about 10%, such as more than about 15%, such as more than about 20%, such as more than about 25%, such as more than about 30% of the surface area of ​​the forming surface 94.

[0120] The highly porous area may occupy greater than about 5%, such as greater than about 10%, such as greater than about 25%, such as greater than about 40%, such as greater than about 50%, such as greater than about 60%, such as greater than about 70%, such as greater than about 80%, such as greater than about 90% of the surface area of ​​the forming surface, and less than about 90%, such as less than about 80%, such as less than about 70%, such as less than about 50%, such as less than about 30%, such as less than about 10% of the surface area of ​​the forming surface.

[0121] As described above, the nonwoven substrate manufactured according to the present disclosure can be formed according to a wet-laid process, a foam forming process, or an air-laid process. The foam forming process can provide various advantages. For example, compared with the wet-laid process, the foam forming process can more easily process longer fibers, requires less water to form the web, and can require less energy to dry the web.

[0122] When forming a nonwoven substrate according to a foam forming process, the wet slurry 76 can be a foamed suspension of individual fibers or fibers combined with other solid materials. In some embodiments, the foaming fluid can account for between about 85% and about 99.99% of the foam (by weight). In some embodiments, the foaming fluid for making the foam can include at least about 85% of the foam (by weight). In certain embodiments, the foaming fluid can account for between about 90% and about 99.9% of the foam (by weight). In certain other embodiments, the foaming fluid can account for between about 93% and 99.5% of the foam, or even between about 95% and about 99.0% of the foam (by weight). In a preferred embodiment, the foaming fluid can be water; however, it is conceivable that other processes can utilize other foaming fluids.

[0123] As described herein, foam forming process can utilize one or more foaming agents, such as surfactant, to form foam. Fiber and surfactant can form stable dispersion together with foaming liquid and any additional components, and described dispersion can basically keep high porosity for a longer time than drying process. In this regard, surfactant is selected to provide foam with at least 2 minutes, more preferably at least 5 minutes, most preferably at least 10 minutes of foam half-life. Foam half-life can be a function of surfactant type, surfactant concentration, foam component / solid level and mixing ability / air content in foam. The foaming surfactant used in the foam can be selected from one or more foaming surfactants known in the art that can provide the foam stability of the desired degree. In this regard, foaming surfactant can be selected from anionic, cationic, nonionic and amphoteric surfactants, provided that they provide necessary foam stability or foam half-life alone or in combination with other components. It should be understood that more than one surfactant can be used, including different types of surfactants (as long as they are compatible) and more than one surfactant of the same type. For example, the combination of cationic surfactant and nonionic surfactant or the combination of anionic surfactant and nonionic surfactant can be used in some embodiments due to its compatibility. However, in some embodiments, combinations of cationic and anionic surfactants may not be satisfactorily combined due to incompatibility between the surfactants.

[0124] Anionic surfactants that are considered suitable for use in the present disclosure include, but are not limited to, anionic sulfate surfactants, alkyl ether sulfonates, alkyl aryl sulfonates, or mixtures or combinations thereof. Examples of alkyl aryl sulfonates include, but are not limited to, alkyl benzene sulfonic acid and its salts, dialkyl benzene disulfonic acid and its salts, dialkyl benzene sulfonic acid and its salts, alkyl phenol sulfonic acid / condensed alkyl phenol sulfonic acid and its salts, or mixtures or combinations thereof. Examples of additional anionic surfactants believed to be suitable for use in the present disclosure include alkali metal sulforicinates; sulfonated glycerides of fatty acids such as sulfonated monoglyceride of coconut oleic acid; salts of sulfonated monovalent alcohol esters such as sodium oleylisethianate; metal soaps of fatty acids; amides of aminosulfonic acids such as the sodium salt of oleylmethyl taurine; sulfonated products of fatty acid nitriles such as palmitonitrile sulfonate; alkali metal alkyl sulfates such as sodium lauryl sulfate, ammonium lauryl sulfate, or triethanolamine lauryl sulfate; ether sulfates having an alkyl group of 8 or more carbon atoms such as sodium lauryl ether sulfate, ammonium lauryl ether sulfate, sodium alkyl aryl ether sulfate, and ammonium alkyl aryl ether sulfate; sulfates of polyoxyethylene alkyl ethers; sodium, potassium, and amine salts of alkylnaphthalenesulfonic acids. Certain phosphate surfactants, including phosphate esters such as sodium lauryl phosphate ester or those available from the Dow Chemical Company under the trade name TRITON, are also believed to be suitable for use herein. A particularly desirable anionic surfactant is sodium dodecyl sulfate (SDS).

[0125] Cationic surfactants are also considered to be suitable for use with the present disclosure in some embodiments of making substrates. In some embodiments, such as those comprising superabsorbent materials, cationic surfactants may be less preferably used due to potential interactions between cationic surfactants and superabsorbent materials (which may be anionic). Foaming cationic surfactants include, but are not limited to, monocarbonyl ammonium salts, dicarbonyl ammonium salts, tricarbonyl ammonium salts, monocarbonyl phosphonium salts, dicarbonyl phosphonium salts, tricarbonyl phosphonium salts, carbonyl carboxyl salts, quaternary ammonium salts, imidazolines, ethoxylated amines, quaternary phospholipids, etc. The example of other cationic surfactants includes various fatty acid amines and amides and their derivatives, and salts of fatty acid amines and amides. Examples of aliphatic fatty acid amines include dodecylamine acetate, octadecylamine acetate, and acetates of amines of tallow fatty acids; homologues of aromatic amines with fatty acids, such as dodecylaniline; fatty amides derived from aliphatic diamines, such as undecylimidazoline; fatty amides derived from aliphatic diamines, such as undecylimidazoline; fatty amides derived from disubstituted amines, such as oleylaminodiethylamine; derivatives of ethylenediamine; quaternary ammonium compounds and salts thereof, for example tallow trimethylammonium chloride, dioctadecyldimethylammonium chloride, didodecyldimethylammonium chloride, dihexadecylammonium chloride, alkyltrimethylammonium hydroxide, dioctadecyldimethylammonium hydroxide, tallow trimethylammonium hydroxide, trimethylammonium hydroxide, methylpolyoxyethylenecocoylammonium chloride, and dipalmitylhydroxyethylmethylammonium sulfate; amide derivatives of amino alcohols, such as β-hydroxyethylstearamide; and amine salts of long-chain fatty acids. Additional examples of cationic surfactants believed to be suitable for use in the present disclosure include benzalkonium chloride, benzethonium chloride, cetrimonium bromide, distearyldimethylammonium chloride, tetramethylammonium hydroxide, and the like.

[0126] Nonionic surfactants that are considered suitable for the present disclosure include, but are not limited to, condensates of ethylene oxide with long-chain fatty alcohols or fatty acids, condensates of ethylene oxide with amines or amides, condensation products of ethylene oxide and propylene oxide, fatty acid alkanolamides, and fatty amine oxides. Various additional examples of nonionic surfactants include stearyl alcohol, sorbitan monostearate, octyl glucoside, octaethylene glycol monododecyl ether, lauryl glucoside, cetyl alcohol, cocamide MEA, glyceryl monolaurate, polyoxyalkylene alkyl ethers (such as polyethylene glycol long chain (12-14C) alkyl ethers), polyoxyalkylene sorbitan ethers, polyoxyalkylene alkoxylates, polyoxyalkylene alkylphenol ethers, ethylene glycol propylene glycol copolymers, polyvinyl alcohol, alkyl polysaccharides, polyethylene glycol sorbitan monooleate, octylphenol ethylene oxide, etc. When the nonwoven substrate contains superabsorbent material, it may be advantageous to use one or more nonionic surfactants.

[0127] The foaming surfactant may be used in different amounts as needed to achieve the desired foam stability and air content in the foam. In certain embodiments, the foaming surfactant may comprise between about 0.005% and about 5% (by weight) of the foam. In certain embodiments, the foaming surfactant may comprise between about 0.05% and 3% of the foam, or even between about 0.05% and about 2% (by weight) of the foam.

[0128] The fiber and / or other solid materials used to form the nonwoven substrate according to the present disclosure can vary according to specific applications and desired results.For example, the nonwoven substrate can be formed by pulp fibers, other natural fibers such as cotton fibers, regenerated cellulose fibers, synthetic polymer fibers, binder fibers, superabsorbent particles and mixtures thereof.For example, when producing tissue products, the nonwoven substrate can include the pulp fibers of an amount greater than about 90 % by weight.When producing wiping products, the nonwoven substrate can be made of independent pulp fibers, or can be made in combination with polymer synthetic fibers such as polyester fibers.When producing the nonwoven substrate for absorbent articles, the nonwoven substrate can include superabsorbent particles combined with at least one type of fiber.At least one type of fiber can include pulp fibers, pulp fibers combined with polymer synthetic fibers, pulp fibers combined with binder fibers, pulp fibers combined with synthetic polymer fibers and binder fibers, pulp fibers combined with regenerated cellulose fibers or any other suitable mixture.

[0129] A wide variety of cellulosic fibers are considered suitable for use herein. In some embodiments, the fibers used may be conventional papermaking fibers, such as wood pulp fibers formed by various pulping processes, such as kraft pulp, sulfite pulp, bleached chemi-thermomechanical pulp (BCTMP), chemi-thermomechanical pulp (CTMP), pressure / pressure thermomechanical pulp (PTMP), thermomechanical pulp (TMP), thermomechanical chemical pulp (TMCP), etc. By way of example only, fibers and methods for preparing wood pulp fibers are disclosed in US4793898 to Laamanen et al., US4594130 to Chang et al., US3585104 to Kleinhart, US5595628 to Gordon et al., US5522967 to Shet, etc. In addition, the fibers may be any high average fiber length wood pulp, low average fiber length wood pulp, or mixtures thereof. Examples of suitable high-average length pulp fibers include softwood fibers such as, but not limited to, northern softwood, southern softwood, redwood, red cedar, hemlock, pine (e.g., southern pine), spruce (e.g., black spruce), etc. Examples of suitable low-average length pulp fibers include hardwood fibers such as, but not limited to, eucalyptus, maple, birch, poplar, etc.

[0130] In one aspect, chemically cross-linked cellulose fibers may be present.Chemically cross-linked cellulose fibers refer to any cellulose fiber material reacted with a cross-linking agent.Cross-linked cellulose fibers may include cross-linked eucalyptus hardwood kraft pulp fibers or softwood fibers.In certain embodiments, the cross-linking agent may include a urea-based cross-linking agent.Suitable urea-based cross-linking agents include substituted ureas, such as hydroxymethylated urea, hydroxymethylated cyclic urea, hydroxymethylated lower alkyl cyclic urea, hydroxymethylated dihydroxy cyclic urea, dihydroxy cyclic urea and lower alkyl substituted cyclic urea. Specific urea-based crosslinking agents include dimethyl dihydroxyurea (DMDHU, 1,3-dimethyl-4,5-dihydroxy-2-imidazolidinone), dimethylol dihydroxy ethylene urea (DMDHEU, 1,3-dimethylol-4,5-dihydroxy-2-imidazolidinone), dimethylol urea (DMU, bis[N-hydroxymethyl]urea), dihydroxy ethylene urea (DHEU, 4,5-dihydroxy-2-imidazolidinone), dimethylol ethylene urea (DMEU, 1,3-dimethylol-2-imidazolidinone) and dimethyl dihydroxy ethylene urea (DMeDHEU or DDI, 4,5-dihydroxy-1,3-dimethyl-2-imidazolidinone). A particularly preferred urea is dimethyl dihydroxy urea (DMDHU, 1,3-dimethyl-4,5-dihydroxy-2-imidazolidinone. Suitable methods for preparing crosslinked fibers include those disclosed in U.S. Pat. No. 5,399,240, the contents of which are incorporated by reference.

[0131] In addition, if desired, secondary fibers obtained from recycled materials, such as fiber pulp from sources such as newsprint, recycled cardboard, and office waste paper, can be used. In a particularly preferred embodiment, refined fibers are utilized in the tissue web, thereby allowing the total amount of virgin and / or high average fiber length wood fibers (such as softwood fibers) to be reduced.

[0132] Regardless of the source of the wood pulp fibers, the wood pulp fibers preferably have an average fiber length greater than about 0.2 mm and less than about 3 mm, such as about 0.35 mm and about 2.5 mm, or between about 0.5 mm and about 2 mm, or even between about 0.7 mm and about 1.5 mm.

[0133] In addition, other cellulose fibers that can be used for the present disclosure include non-wood fibers. As used herein, the term "non-wood fibers" generally refers to cellulose fibers derived from non-wood monocotyledonous or dicotyledonous plant stems. Non-limiting examples of dicotyledonous plants that can be used to produce non-wood fibers include kenaf, jute, flax, ramie and hemp. Non-limiting examples of monocotyledonous plants that can be used to produce non-wood fibers include cereal straw (wheat, rye, barley, oats, etc.), stalks (corn, cotton, sorghum, hemp, etc.), rattan (bamboo, sisal, bagasse, etc.) and grasses (miscanthus, Spanish grass, lemon, sabai, switchgrass, etc.). In other certain cases, non-wood fibers can be derived from aquatic plants such as water hyacinth, microalgae such as spirulina and large seaweed such as red algae or brown algae.

[0134] Additionally, other cellulosic fibers used to make the substrates herein may include synthetic cellulosic fiber types formed by spinning, including rayon in all its types, and other fibers derived from viscose or chemically modified cellulose, such as, for example, those available under the trade names LYOCELL and TENCEL.

[0135] In some embodiments, non-wood and synthetic cellulose fibers can have a fiber length greater than about 0.2 mm, including, for example, having an average fiber size between about 0.5 mm and about 30 mm, or between about 0.75 mm and about 8 mm, or even between about 1 mm and about 5 mm. Cellulose fibers such as pulp fibers can typically be present in the nonwoven substrate in an amount of about 5% by weight to about 60% by weight (including all 1% by weight increments therebetween).

[0136] Additional fibers that can be used in the present disclosure include synthetic polymer fibers. By way of non-limiting example, such fibers are composed of polyolefins, polyesters (PET), polyamides, polylactic acid, or other fiber-forming polymers. Polyolefin fibers such as polyethylene (PE) and polypropylene (PP) are particularly suitable for use in the present disclosure.

[0137] The synthetic polymer fiber can have a fiber length greater than about 0.2mm, including for example having an average fiber size between about 0.5mm and about 50mm or between about 0.75mm and about 15mm or between about 1mm and about 12mm. In one embodiment, the synthetic polymer fiber can be a staple fiber having a fiber length greater than about 2mm, such as greater than about 3mm, such as greater than about 4mm, and usually less than about 8mm, such as less than about 7mm, such as less than about 6mm, such as less than about 5mm, such as less than about 4mm. The polymer fiber can have a fiber length less than about 5 deniers, such as less than about 3 deniers, such as less than about 2 deniers, and greater than about 0.5 deniers, such as greater than about 1 denier size.

[0138] When present in a nonwoven substrate, the synthetic polymeric fibers generally may be included in the substrate in an amount from about 3 weight percent to about 80 weight percent, including all 1 weight percent increments therebetween.

[0139] In one embodiment, the fiber furnish may include a binder material that, once activated, reinforces the substrate. For example, the fiber furnish may include binder fibers that, when heated, such as during drying of the substrate, bond to adjacent fibers.

[0140] Binder materials that can be used in the present disclosure may include but are not limited to thermoplastic binder fibers, such as PET / PE bicomponent binder fibers and water-compatible adhesives, such as latex. In some embodiments, the binder material used herein can be in powder form, such as thermoplastic PE powder. Importantly, the binder may include a binder that is insoluble in water on a dry substrate. In certain embodiments, the latex used in the present disclosure may be cationic or anionic to facilitate application and adhesion to the cellulose fibers that can be used herein. For example, it is considered that the latex that is suitable includes but is not limited to anionic styrene-butadiene copolymers, polyvinyl acetate homopolymers, vinyl acetate-ethylene copolymers, vinyl acetate-acrylic acid copolymers, ethylene-vinyl chloride copolymers, ethylene-vinyl chloride-vinyl acetate terpolymers, acrylic acid polyvinyl chloride polymers, acrylic acid polymers, nitrile polymers, and other suitable anionic latex polymers known in the art. Examples of such latexes are described in US4785030 granted to Hager, US6462159 granted to Hamada, US6752905 granted to Chuang et al., etc. Examples of suitable thermoplastic binder fibers include, but are not limited to, monocomponent and multicomponent fibers of thermoplastic polymers such as polyethylene having at least one relatively low melting point. In certain embodiments, polyethylene / polypropylene sheath / core staple fibers may be used. The binder fibers may have lengths consistent with those described above for synthetic polymer fibers.

[0141] Binders in liquid form, such as latex emulsions, may comprise between about 0% and about 10% (by weight) of the substrate. When used, binder fibers may be added to the other components in proportion to obtain the desired fiber ratio and structure. For example, in some embodiments, binder fibers may comprise between about 0% and about 50% of the total fiber weight, more preferably between about 5% and about 40% of the total fiber weight in some embodiments.

[0142] An additional additive that can be added during the formation of substrate 12 as described herein can be a superabsorbent material (SAM). SAM is generally provided in particulate form, and in some aspects, can include polymers of unsaturated carboxylic acids or their derivatives. These polymers are generally made water-insoluble, but water-swellable, by crosslinking the polymer with a difunctional or multifunctional internal crosslinking agent. These internally crosslinked polymers are at least partially neutralized, and generally contain pendant anionic carboxyl groups on the polymer backbone, which enable the polymer to absorb aqueous fluids, such as body fluids. Generally, SAM particles are post-treated to crosslink pendant anionic carboxyl groups on the particle surface. SAM is manufactured by known polymerization techniques, ideally by gel polymerization in aqueous solution. The product of this polymerization process is an aqueous polymer gel, i.e., a SAM hydrogel that is reduced in size to small particles by mechanical force, and then dried using drying procedures and equipment known in the art. After the drying process, the resulting SAM particles are crushed to a desired particle size. Examples of superabsorbent materials include, but are not limited to, those described in US7396584 to Azad et al., US7935860 to Dodge et al., US2005 / 5245393 to Azad et al., US2014 / 09606 to Bergam et al., WO2008 / 027488 to Chang et al., and the like. In addition, to aid processing, the SAM may be treated so that the material is temporarily non-absorbent during the formation of the foam and the formation of the highly expanded foam. For example, in one aspect, the SAM may be treated with a water-soluble protective coating having a selected dissolution rate so that the SAM is substantially not exposed to the aqueous carrier until the highly expanded foam has been formed and the drying operation has begun. Alternatively, to prevent or limit premature expansion during processing, the SAM may be introduced into the process at low temperatures.

[0143] Superabsorbent material can be incorporated into nonwoven substrates generally in an amount of about 1 wt % to about 90 wt % (including all 1 wt % increments therebetween). For example, superabsorbent material can be greater than about 10 wt %, such as greater than about 30 wt %, such as greater than about 50 wt %, such as greater than about 70 wt %, such as greater than about 80 wt %, and generally less than about 90 wt %, such as less than about 85 wt %, such as less than about 80 wt % in substrate.

[0144] In one aspect, the nonwoven substrate manufactured according to the present disclosure can be a multilayer substrate. The superabsorbent material can be contained only in the middle layer of the substrate. In this way, the superabsorbent material is encapsulated in the nonwoven substrate. In addition, in this embodiment, the superabsorbent material is preferentially present in the high basis weight area. Therefore, if the nonwoven substrate is cut into strips, almost no superabsorbent material escapes.

[0145] Other additives that may be incorporated into the nonwoven substrate include wet strength additives, permanent wet strength additives, temporary wet strength additives, dry strength additives, and the like.

[0146] Additional additives that may be added to the substrate include one or more pigments, opacifiers, antimicrobial agents, pH adjusters, skin benefit agents, odor absorbers, fragrances, heat-expandable microspheres, foam particles (such as crushed foam particles), etc., as needed to impart or improve one or more physical or aesthetic properties. In certain embodiments, the substrate may contain skin benefit agents such as antioxidants, astringents, conditioners, emollients, deodorants, topical analgesics, film formers, humectants, hydrotropes, pH adjusters, surface modifiers, skin care agents, etc.

[0147] When used, miscellaneous components desirably comprise less than about 2% by weight of the matrix.

[0148] The present disclosure may be better understood by reference to the following examples.

[0149] Example

[0150] The following examples were produced according to the present disclosure. These examples were produced according to a wet-laid process. However, as described above, in other embodiments, the substrate can be made according to a foam forming process.

[0151] Example 1

[0152] A nonwoven substrate is formed on a forming surface including high porosity areas and low porosity areas. The forming surface is made of a woven fabric. Parallel resin stripes are printed onto the top surface of the fabric to form the low porosity areas. The resin creates raised areas on the fabric. Specifically, the stripes are 1.5 mm high, 3 mm wide, and have a semi-elliptical cross-section.

[0153] An aqueous fiber suspension containing 17.5 g superabsorbent particles, 1.19 g northern softwood kraft fibers, 0.71 g bicomponent binder fibers, and 0.47 g polyester fibers was prepared. The bicomponent fibers had a size of 2.2 dTex and a length of 6 mm. The bicomponent fibers included a core made of high temperature polyester and a sheath made of low temperature polyethylene. The polyester fibers had a size of 6.7 dTex and also had an average fiber length of 6 mm.

[0154] The aqueous fiber suspension is deposited onto a forming surface and a nonwoven substrate is formed. In particular, the above fibers and superabsorbent particles are added to 4 liters of water, stirred, and quickly deposited onto the forming surface. The wet nonwoven substrate is dried and cured at 134°C to bond the binder fibers. The resulting nonwoven substrate includes low basis weight areas and high basis weight areas corresponding to the pattern of high porosity areas and low porosity areas on the forming surface. The nonwoven substrate is continuous and does not contain any holes.

[0155] Example 2

[0156] In the present embodiment, the forming surface described in Example 1 is inverted and used to produce a nonwoven substrate. Therefore, the forming surface is flat and does not include any raised areas. Use the same procedure to produce a nonwoven substrate. The resulting nonwoven material has high basis weight areas and low basis weight areas corresponding to the high porosity areas and low porosity areas on the forming surface. The nonwoven substrate produced is continuous, which shows that raised areas are unnecessary for producing high and low basis weight substrates.

[0157] Example 3

[0158] In this example, the forming surface is made of a woven fabric. 4 mm wide pillars are applied to the forming surface using 3D printing. An additive material is impregnated into the fabric to create low porosity areas that do not protrude from the surface of the fabric.

[0159] The same fiber furnish and process as described in Example 1 were used to produce a wet-laid nonwoven substrate. The resulting nonwoven substrate had low basis weight fluid control channels surrounded by high basis weight regions. The nonwoven substrate was continuous. The high basis weight regions had a basis weight of 600 gsm, and the low basis weight regions had a basis weight of 160 gsm. Thus, the low basis weight regions represented a basis weight reduction of more than 70%.

[0160] Example 4

[0161] In this example, the forming surface is made of a woven fabric. The fabric includes holes with a diameter of 0.42 mm. An additive material is applied to the surface of the fabric using 3D printing. In particular, two 6 mm wide elongated columns are applied to the fabric, which produce raised areas on the fabric with a height of 2 mm. The cross-sectional shape of the columns is semi-elliptical. Another two 6 mm columns are also applied to the surface of the fabric, but are formed by a 3D printer so that the additive material impregnates the fabric without producing any raised features. All four elongated columns contain no holes and therefore have zero porosity.

[0162] The process and the same fiber furnish described in Example 1 were used to produce a nonwoven substrate. The resulting nonwoven substrate had voids or pores corresponding to the locations of the nonporous pillars. Thus, the sheet produced was discontinuous.

[0163] Example 5

[0164] In this example, the forming surface is formed of a woven fabric. The additive material is applied to the surface of the fabric using 3D printing. The additive material is impregnated into the fabric to form 8 mm wide pillars. The pillars do not produce raised areas on the fabric. Each pillar includes a continuous matrix of the additive material. However, 3D printing is used to create small openings of approximately 1 mm x 1 mm in a staggered pattern within the pillars. The total open area of ​​the pillars is about 3%.

[0165] The fiber furnish and process described in Example 1 were used to produce a nonwoven substrate. The resulting nonwoven substrate had low basis weight fluid control channels corresponding to the locations of the printed columns. Due to the porosity of the printed columns, the low basis weight regions contained fibers and superabsorbent particles to form a continuous sheet. The low basis weight regions had a thickness of 0.5 mm. The difference in thickness between the high basis weight regions and the low basis weight regions was 4.1 mm. The basis weight difference was substantially equal to the thickness difference.

[0166] Example 6

[0167] In this example, the forming surface is formed of a woven fabric. An additive material is applied to the surface to form high porosity areas and low porosity areas. The forming surface is similar to Fig. 9 The illustrated forming surface has a low porosity zone having a width of about 12 mm and a high porosity zone having a width of about 84 mm.

[0168] Similar to Figure 1 and Figure 2 The illustrated process uses a foam forming continuous process pilot line to produce a nonwoven substrate. The nonwoven substrate is similar in appearance to Fig.10 Exemplified Nonwoven Substrates. In this embodiment, a multi-layer substrate is produced wherein the superabsorbent material is contained within an intermediate layer located between the top and bottom fibrous layers.

[0169] All documents cited in the specific embodiments are, in relevant parts, incorporated herein by reference; the citation of any document should not be construed as an admission that it is prior art with respect to the present invention. In the event that any meaning or definition of a term in this written document conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this written document shall prevail.

[0170] These and other modifications and variations of the present invention may be practiced by those of ordinary skill in the art without departing from the spirit and scope of the present invention as more particularly described in the appended claims. In addition, it should be understood that the aspects of the various embodiments may be interchangeable in whole or in part. In addition, it will be appreciated by those of ordinary skill in the art that the foregoing description is by way of example only and is not intended to limit the present invention as further described in such appended claims.

Claims

1. A method for forming a nonwoven substrate, comprising: depositing a wet fiber suspension onto a forming surface, the fiber suspension comprising at least a first type of fibers having an average fiber length, the forming surface comprising a pattern of porous first regions and porous second regions, the first regions having a porosity greater than a porosity of the second regions, the porosity of the second regions being at least 50% less than the porosity of the first regions; and Fluid is discharged from the forming surface so as to form a nonwoven substrate having regions of high basis weight corresponding to the first zones and regions of low basis weight corresponding to the second zones.

2. The method of claim 1, wherein the porosity of the second zone is at least 80% less than the porosity of the first zone, such as at least 90% less, such as at least about 95% less.

3. A method as claimed in any one of the preceding claims, wherein the second zone has a porosity such that the second zone has an open area of ​​about 0.5% to about 20%, such as about 1% to about 10% open area.

4. A method as claimed in any one of the preceding claims, wherein the fiber suspension comprises a plurality of different types of fibers and the width dimension of the second zone is greater in distance than the average fiber length of the fiber type having the longest fibers in the fiber suspension.

5. The method according to any one of the preceding claims, wherein the fiber suspension comprises superabsorbent particles.

6. A method as claimed in any one of the preceding claims, wherein the width dimension of the second zone is greater than about 4 mm, such as greater than about 5 mm, such as greater than about 6 mm, such as greater than about 7 mm, and less than about 10 mm.

7. A method as claimed in any one of the preceding claims, wherein the second zones form pillars on the forming surface.

8. The method of claim 7, wherein the pillars are linear and parallel.

9. The method of claim 7 or 8, wherein the pillars have a width dimension of about 4 mm to about 10 mm, and the pillars are spaced apart a distance of about 6 mm to about 20 mm.

10. The method of any one of the preceding claims, wherein the nonwoven substrate is wound into a roll.

11. The method of any of the preceding claims, further comprising the step of cutting the nonwoven substrate along the second zone.

12. A method according to any one of the preceding claims, wherein the basis weight of the low basis weight regions is more than about 50% less than the basis weight of the high basis weight regions, such as more than about 70% less.

13. A method according to any one of the preceding claims, wherein the thickness of the low basis weight regions is more than about 50% less than the thickness of the high basis weight regions, such as more than about 70% less.

14. A method as claimed in any one of the preceding claims, wherein the forming surface is flat and does not include raised areas on the top surface.

15. A method as claimed in any preceding claim, wherein the forming surface comprises a fabric formed from woven yarns, the second region comprising a region to which an additive material has been applied to the fabric.

16. A method as claimed in any one of the preceding claims, wherein the wet fiber suspension comprises a blend of synthetic polymer fibers, pulp fibers, superabsorbent particles or mixtures thereof.

17. A method as claimed in any one of the preceding claims, wherein the wet fibre suspension comprises polymeric synthetic fibres.

18. A method as claimed in any one of the preceding claims, wherein the wet fibre suspension comprises a foamed fibre suspension to produce a foam-formed substrate.

19. A method as claimed in any one of the preceding claims, wherein the foamed fiber suspension is formed by combining a foam with a fiber furnish, the foam having a density of about 200 g / L to about 600 g / L, such as about 250 g / L to about 400 g / L.

20. The method of any of the preceding claims, wherein the foamed suspension is formed by combining a foaming agent with water, the foamed fiber suspension comprising from about 40% to about 80% air by volume.

21. The method of claim 1, wherein the dried nonwoven substrate has an average basis weight of about 20 gsm to about 800 gsm, such as about 30 gsm to about 200 gsm.

22. The method of any one of the preceding claims, wherein the nonwoven substrate is continuous.

23. The nonwoven material of any one of the preceding claims, wherein the nonwoven material comprises pulp fibers.

24. A formed sheet for producing a nonwoven substrate, comprising: A forming mesh comprising a fabric formed from woven yarns, the fabric comprising a top forming surface, the top forming surface comprising a pattern of a porous first zone and a porous second zone, the porosity of the first zone being greater than the porosity of the second zone, the porosity of the second zone being at least 50% less than the porosity of the first zone, the second zone having a width dimension greater than about 4 mm.

25. The formed sheet of claim 24 wherein the second region comprises a region where an additive material has been applied to the fabric.

26. A formed sheet as claimed in claim 24 or 25, wherein the second regions comprise parallel columns.

27. A formed sheet as claimed in claim 24 or 25, wherein the second regions form a grid-like pattern.

28. The formed sheet of claim 26, wherein the pillars have a wavy shape.

29. A nonwoven substrate comprising: a continuous nonwoven web having a first surface and an opposing second surface, the nonwoven web comprising synthetic polymer fibers; The nonwoven web has an average basis weight of about 30 gsm to about 800 gsm; And wherein the nonwoven web comprises a pattern of high basis weight regions and low basis weight regions, wherein the basis weight of the low basis weight regions is at least about 50% less than the basis weight of the high basis weight regions.

30. The nonwoven substrate of claim 29, wherein the nonwoven substrate further comprises binder fibers.

31. The nonwoven substrate of claim 29, wherein the nonwoven substrate further comprises pulp fibers.

32. The nonwoven substrate of claim 29, wherein the nonwoven substrate further comprises a superabsorbent material, the superabsorbent material being present in the nonwoven substrate in an amount of about 10% to about 90% by weight.

33. The nonwoven substrate of claim 32, wherein the nonwoven substrate comprises a top layer, a middle layer, and a bottom layer, and wherein all of the superabsorbent material is contained in the middle layer.

34. The nonwoven substrate of any one of claims 29 to 33, wherein the thickness of the low basis weight regions is at least about 50% less than the thickness of the high basis weight regions.

35. The nonwoven substrate of any one of claims 29 to 34, wherein the density of the low basis weight regions is at least about 50% less than the density of the high basis weight regions.

36. The nonwoven substrate of any one of claims 29 to 35, wherein the nonwoven substrate further comprises crosslinked pulp fibers.

37. The nonwoven substrate of any one of claims 29 to 36, wherein the nonwoven substrate has a basis weight greater than about 100 gsm, such as greater than about 150 gsm, and less than about 800 gsm.

38. The nonwoven substrate of claim 30, wherein the binder fiber is present in an amount from about 5% to about 40% by weight.

39. The nonwoven substrate of any one of claims 29 to 38, wherein the synthetic polymer fibers are present in the nonwoven substrate in an amount of about 3% to about 35% by weight.

40. An absorbent article comprising: Fluid permeable lining; External covering; as well as An absorbent core is positioned between the liner and the outer cover, the absorbent core comprising the nonwoven substrate of claim 29.

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