Methods of making absorbent composites and absorbent articles employing same

Abstract

An absorbent core composite for a disposable absorbent article is disclosed. The absorbent core composite has a first fabric, a body-side second fabric, and a plurality of superabsorbent particle (SAP) aggregates located between the first fabric and the second fabric. Around each of the plurality of SAP aggregates, an arrangement of spatially separated binding sites secures the second fabric to the first fabric and forms a pocket in which the SAP aggregates are secured between the first fabric and the second fabric. The body-side second fabric is a bulk non-woven fabric comprising fibers entangled with at least some of the particles in an SAP aggregate.

Description

background

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 61 / 801,620 (pending), filed March 15, 2013, the entire contents of which are incorporated herein by reference for all purposes and made a part hereof.

[0002] The present invention generally relates to absorbent composites (or absorbent core laminates) and methods of making absorbent composites. The present invention also generally relates to disposable absorbent articles employing absorbent composites and methods of making the same. Such disposable absorbent articles include diapers, training pants, adult incontinence products, body exudate absorbing products, feminine hygiene products, and other absorbent products (collectively referred to as "disposable absorbent articles" or "disposable absorbent products").

[0003] Disposable absorbent articles generally use three basic structural elements: a top layer forming the inner surface, a back layer forming the outer surface, and an absorbent core placed between the top layer and the back layer. The top layer is designed to allow liquid to pass from the outside of the absorbent article through the top layer and into the absorbent core. The top layer can be made of a variety of hydrophilic or hydrophobic materials that are permeable to liquid and vapor. The permeability of the top layer can be increased by using a surface active agent ("surfactant"). The surfactant reduces the contact angle or surface energy of the liquid-solid cross section and promotes the passage of liquid through the top layer.

[0004] The back layer is designed to prevent fluid from passing through the back layer and out of the absorbent article from the absorbent core. The back layer can be made of an impermeable film extending the full width of the article or a combination of a garment-like material and an impermeable film. The back layer can also have vapor transmission properties ("breathability") that allow vapor to pass through the back layer without releasing the fluid stored in the absorbent core. The back layer can also be made of a nonwoven material that is impermeable to liquids but can transmit vapor, such as spunbond, meltblown, spunbond ("SMS"); spunbond, meltblown, meltblown, spunbond ("SMMS"); micron, nano or splittable fibers; spunmelt or spunlace; combing, etc.

[0005] Absorbent core is designed to hold and distribute the fluid through top layer.General absorbent core is made of high or super absorbent polymer (SAP) of absorbent matrix stabilization.SAP is made of following materials usually: polyvinyl alcohol, polyacrylate, various grafted starches, and cross-linked sodium polyacrylate.SAP can be particles, fibers, foams, nets, balls, aggregates, and films of regular or irregular shapes.Absorbent matrix is ​​generally defibrinated wood pulp or similar materials.Absorbent matrix is ​​very fluffy relative to top layer, back layer and SAP.Most of the thickness of diaper comes from absorbent core.

[0006] Interestingly, consumers of absorbent articles are demanding thinner absorbent articles. In order to meet these demands, manufacturers are reducing the thickness of absorbent articles by reducing the amount of absorbent matrix used in the absorbent core. Although the resulting absorbent cores are thinner, their performance is defective. Due to the reduction in the amount of absorbent matrix, the effect of stabilizing SAP-preventing SAP from migrating in the absorbent core is poor. Due to the migration of SAP in the core, the absorbent core loses its effect and no longer has uniform absorbency. For example, SAP that does not contain tends to gather in a group in the wetted area and cannot effectively handle subsequent excretion.

[0007] Manufacturers have tried to solve this problem by creating small individual SAP bags or by gluing SAP. However, these solutions have been largely unsuccessful. SAP bags only limit migration to movement within the bag. However, since there is still particle movement, the absorbent core does not show uniform absorbency. Gluing SAP stabilizes the SAP, but results in an uncomfortable harder absorbent core and loss of SAP swelling capacity. Applicants have found that many methods containing SAP may negatively impact the ability of the SAP and absorbent core to receive and distribute intake.

[0008] Therefore, there is a need for improved absorbent products that continue the trend of reducing product thickness while minimizing product hardness and demonstrating outstanding absorption and fluid handling properties in addition. The specification of U.S. Patent No. 8,148,598, which is jointly assigned and designated by at least one co-inventor of the present invention, describes prior improvements to the state of the art and serves as background for the present invention. U.S. Patent No. 8,148,598 is incorporated herein by reference in its entirety for all purposes and forms a part of the present invention. In one aspect, the present invention can be considered to have continued and developed this effort to provide improved absorbent products and methods of manufacture thereof. Summary of the invention

[0009] In one aspect, the present invention provides an improved absorbent composite and a method for making the same. The embodiments described focus on the composition or component arrangement of the absorbent composite. In one embodiment, the absorbent core composite of a disposable absorbent article has a first fabric, a second fabric on the body side, and an aggregate of multiple superabsorbent particles (SAP) located between the first fabric and the second fabric. Around each of the multiple SAP aggregates, the arrangement of spaced-apart binding sites fixes the second fabric to the first fabric and forms a bag, in which the SAP aggregate is fixed between the first fabric and the second fabric. The second fabric on the body side is a fluffy nonwoven fabric, including fibers entangled with at least some particles in the SAP aggregate. In a preferred embodiment, an adhesive pattern (e.g., a pattern having multiple interconnected rings defining an open area without adhesive) can be pre-applied to the first fabric.

[0010] In another aspect, a method for making an absorbent composite laminate for a disposable absorbent article is disclosed. The method includes conveying a first fabric to a position to receive superabsorbent particles (SAP) and depositing SAP on the first fabric to provide discrete aggregates of SAP. A second fabric of a fluffy nonwoven is then conveyed and placed relative to the first fabric so that the fibers of the fluffy nonwoven entangle the particles in the top particle layer of the SAP aggregates. This at least partially fixes the SAP aggregates between them. The first fabric and the second fabric are then combined at a network of binding sites to form an elongated laminate having a plurality of SAP aggregate pockets, whereby each pocket is defined by the binding sites located around the SAP aggregates and the second fabric is fixed to the first fabric; and the elongated laminate is conveyed so that the fluffy nonwoven and the bag prevent the SAP particles from migrating from the bag. In a preferred embodiment, the binding sites are binding points and / or binding sites that form diamond-shaped pockets and corresponding grids without any straight path directly to the side edges.

[0011] A disposable absorbent article is also disclosed having a chassis defined by a first end edge and a second end longitudinally spaced from the first end edge, the end edge portions defining front and rear waist regions that can be fastened around the waist of a user. The article also includes a top layer, a back layer, and an absorbent composite disposed between the top layer and the back layer. The absorbent composite includes a first fabric, a second fabric bonded to the first fabric, and absorbent particles secured between the first and second fabrics. The first fabric is intermittently bonded to the second fabric to define a plurality of pockets located between the first fabric and the second fabric and containing aggregates of superabsorbent particles (SAP), wherein discontinuous and spaced-apart bonding sites secure the first fabric to the second fabric. The second fabric is a bulky nonwoven material located on the body side of the absorbent composite and on the SAP aggregates, such that fibers of the bulky nonwoven entangle the superabsorbent particles, wherein the SAP aggregates are free of absorbent matrix in a middle portion extending from below the bulky nonwoven material.

[0012] In another aspect, an absorbent composite is disclosed, which has a bulky nonwoven substrate, a face fabric bonded to the bulky nonwoven substrate, and a superabsorbent particle (SAP) layer fixed therebetween. In addition, a hot melt adhesive is interspersed with the SAP to mutually fix the SAP to the bulky nonwoven substrate and the face fabric. The face fabric can be a cotton material in a preferred embodiment.

[0013] In another aspect, a method for making an absorbent composite is disclosed. The method includes conveying a first substrate of nonwoven material, delivering a mixture of hot melt adhesive and superabsorbent particles (SAP) to the conveyed first substrate, and, as the first substrate containing the mixture is conveyed, applying heat to the first substrate, thereby activating the hot melt adhesive particles and bonding the SAP to the hot melt particles and the first substrate. A second substrate is then applied on top of the first substrate and the SAP layer bonded thereto.

[0014] Various embodiments are disclosed in which aggregates of absorbent particles are strategically located and / or formed between a top layer and a bottom layer and across regions of a composite or core. By varying the location of the aggregates or confining the aggregates, the performance and capacity of the absorbent composite can be managed or affected. In certain embodiments, the aggregates of absorbent particles are located in a container or bag. In other embodiments, the storage, spacing, arrangement, and / or geometry or shape of the container or bag are specifically provided to achieve specific core fluid handling properties.

[0015] In one embodiment, a disposable absorbent article comprises a chassis body defined by a first end edge and a second end longitudinally spaced from the first end edge, the end edge portions defining front and rear waist regions that can be fastened around the waist of a user. The article further comprises a top layer, a back layer, and an absorbent composite disposed between the top layer and the back layer. The top layer and the back layer define the longitudinal and transverse edges of the chassis body. The absorbent composite comprises a first fabric and a second fabric bonded to the first fabric. In addition, absorbent particles are bonded between the first and second fabrics, wherein the first fabric is intermittently connected to the second fabric to define a plurality of containers located between the first fabric and the second fabric and containing aggregates of absorbent particles. The absorbent composite comprises a container region of absorbent particle aggregates, comprising a primary region of containers having a first size and a secondary region of containers having a plurality of second sizes different from the first size.

[0016] The present invention relates to an absorbent composite (which, in some embodiments, does not require an absorbent matrix) and a novel method for making the absorbent composite. The present invention also discloses absorbent articles incorporating the absorbent composite. The absorbent composite provides an absorbent article that can be made very thin and soft while retaining enough SAP to provide adequate absorbency and dry and wet integrity (uniform absorbency). Although the use of the absorbent composite in diapers is described, those skilled in the art will appreciate that the absorbent composite made by the method of the present invention can be used in a variety of absorbent products.

[0017] The present invention also relates to improved absorbent articles incorporating absorbent composites.

[0018] In one embodiment, a method for producing a composite sheet is described, the method comprising the steps of positioning a first fabric to receive particles, depositing particles on the first fabric, applying an adhesive to a second fabric, positioning the second fabric relative to the first fabric, and forming bonding sites extending between the first fabric and the second fabric. The method may also include an article, wherein the particles include SAP particles, skin care particles, odor absorbing particles, adhesive particles, ion exchange particles, and combinations thereof. Additionally, the method may include the step of coating the particles with a hydrophobic material.

[0019] The method may include conforming the first fabric to the surface. The surface may include depressions that form pockets or containers in the first fabric when the first fabric conforms to the surface. SAP particles may be introduced into the pockets formed in the first fabric. Suction may be used to conform the first fabric to the surface. The adhesive applied to the second fabric may be applied at a concentration sufficient to fix an effective amount of dry particles. This concentration is generally 1 to 100 grams per square meter. More specifically, adhesive may be applied at a concentration of 5 to 75 grams per square meter, or even more preferably 12 to 50 grams per square meter. Adhesive may be applied in a manner such that the total amount of particles bonded by the adhesive is 1 to 100 grams per square meter. The method of the present invention also includes a step of applying adhesive to the first fabric before particles are deposited on the first fabric.

[0020] The binding sites suitable for use in the method can be binding lines, which can be continuous or discontinuous and can define pockets or other shapes and designs. Alternatively, the binding sites can be binding points. The binding points can be positioned and / or arranged relative to the particles to prevent linear particle migration exceeding 2 inches.

[0021] Alternatively, the method includes placing a first fabric to receive particles, placing particles on the first fabric, placing the particles relative to the first fabric, placing a second fabric on the particles, and forming binding sites connecting the first fabric and the second fabric. The binding sites can be discrete points spaced to prevent particle migration. The binding sites can also be binding lines spaced to prevent particle migration, or binding lines connected to form a single binding line. The binding lines can be arranged to form a bag in which some particles are placed. The particles can be SAP particles, skin care particles, odor absorbing particles, adhesive particles, ion exchange particles and combinations thereof. The particles can be fixed to the first fabric with an adhesive, a thermoplastic material or a combination thereof. Additionally or alternatively, the particles can be fixed to the second fabric with an adhesive, a thermoplastic material or a combination thereof. In addition, a shape can be formed in the first fabric to receive the particles.

[0022] The disposable absorbent article of the present invention may comprise a top layer, a back layer and an absorbent core fixed therebetween, wherein at least a portion of one of the top layer, the back layer and the absorbent core. The absorbent core comprises a first fabric, a second fabric combined with the first fabric, and particles bonded between the first fabric and the second fabric. The particles may be SAP particles, skin care particles, odor absorbing particles, bonding particles, ion exchange particles and combinations thereof.

[0023] Alternatively, an absorbent layer can be provided, which is supported on the back layer so that a portion of the back layer provides a second fabric of the absorbent composite. The back layer can also include a first back layer, a second back layer and SAP particles at a concentration of about 20gsm between them, and the second back layer is an SMS with a basis weight of about 10gsm to 60gsm. The absorbent layer can be bonded between the first fabric and the second fabric at a bonding concentration of 1 to 100 grams per square meter. The first fabric can be connected to the second fabric at discrete points, and these discrete points can define a bag. In addition, the first fabric can be combined with the second fabric along a plurality of bonding lines, and these bonding lines can define a bag.

[0024] The absorbent core may also include a first fabric, a second fabric, a bonding site to which the first fabric and the second fabric are attached; and a layer of absorbent particles bonded between the first fabric and the second fabric. The particles may be SAP particles and / or other beneficial particles. The absorbent layer may be supported under a portion of the top layer so that the portion of the top layer provides the second fabric of the absorbent composite. The absorbent layer may be supported under a portion of the back layer so that the portion of the back layer provides the first fabric of the absorbent composite.

[0025] In some embodiments, a disposable absorbent article may include SAP particles in an absorbent layer at a concentration of about 50 to 650 grams per square meter. The SAP particles may also be coated with a hydrophobic material to impart an initial liquid receptivity to the SAP particles in the absorbent layer. The binding sites may define a plurality of continuous lines that prevent the movement of the absorbent layer SAP particles. The continuous lines may be shaped to form a pocket between the first fabric and the second fabric. The binding sites may define a plurality of discontinuous lines that prevent the movement of the absorbent layer SAP particles. The discontinuous lines may be shaped to form a pocket between the first fabric and the second fabric.

[0026] In another embodiment, the bonding may be along the perimeter of the particle bag. The bonding may form a pattern such as a herringbone, brick, circle, triangle, dot, dashed line, rectangle, and combinations thereof. Another embodiment may also include loose particles between the first and second sheets.

[0027] The foregoing has described rather broadly the features and technical advantages of the present invention so that the following detailed description can be better understood. Other features and advantages are described below. It should be understood that the specific embodiments described herein may be readily used as improvements or other structures designed to perform the same purposes. It should be understood that such equivalent structures do not depart from the disclosure set forth in the appended claims. Features that are considered to be characteristic of the present invention, as to its construction and operation of the method, as well as other objects and advantages, etc., may be combined with the following detailed description and the appended claims. Figure 1 The present invention is better understood by referring to the accompanying drawings. However, it should be understood that the drawings are only for illustration and explanation and are not intended to limit the present invention. The disposable absorbent article of the present invention may include a top layer, a back layer and an absorbent core disposed therebetween. The absorbent core is an absorbent composite comprising a first fabric, a second fabric combined with a second fabric, and particles fixed between the first fabric and the second fabric. The particles may be SAP particles, skin care particles, odor absorbing particles, adhesive particles, ion exchange particles, and combinations thereof, or in a preferred embodiment, consist of SAP.

[0028] Alternatively, an absorbent layer can be provided, which is supported on the back layer so that a portion of the back layer provides a second fabric of the absorbent composite. The back layer can also include a first back layer, a second back layer and a concentration of about 20gsm SAP particles between them, and the second back layer is a SMS with a basis weight of about 10gsm to 60gsm. The absorbent layer can be bonded between the first fabric and the second fabric at a concentration of 1 to 100 grams per square meter. The first fabric can be connected to the second fabric at discrete points, and these discrete points can define a bag. In addition, the first fabric can be combined with the second fabric along multiple lines, and these bonding lines can define a bag.

[0029] The absorbent core may also include a first fabric, a second fabric, a bonding site to which the first fabric and the second fabric are attached; and a layer of absorbent particles bonded between the first fabric and the second fabric. The particles may be SAP particles and / or other beneficial particles. The absorbent layer may be supported under a portion of the top layer so that the portion of the top layer provides the second fabric of the absorbent composite. The absorbent layer may be supported under a portion of the back layer so that the portion of the back layer provides the first fabric of the absorbent composite.

[0030] In some embodiments, a disposable absorbent preparation may include a concentration of about 50 to 650 SAP particles per square meter in the absorbent layer. The SAP particles may also be coated with a hydrophobic material to impart an initial liquid receptivity to the SAP particles in the absorbent layer. The binding sites may define a plurality of continuous lines that prevent the movement of the absorbent layer SAP particles. The continuous lines may be shaped to form pockets between the first fabric and the second fabric. The binding sites may define a plurality of discontinuous lines that prevent the movement of the absorbent layer SAP particles. The discontinuous lines may be shaped to form pockets between the first fabric and the second fabric.

[0031] In another embodiment, the bonding may be along the perimeter of the particle bag. The bonding may form a pattern such as a herringbone, brick, circle, triangle, dot, dashed line, rectangle, and combinations thereof. Another embodiment may also include loose particles between the first and second sheets.

[0032] The foregoing has described rather broadly the features and technical advantages of the present invention so that the following detailed description can be better understood. Other features and advantages are described below. It should be understood that the specific embodiments described herein may be readily used as improvements or other structures designed to perform the same purposes. It should be understood that such equivalent structures do not depart from the disclosure set forth in the appended claims. Features that are considered to be characteristic of the present invention, as to its construction and operation of the method, as well as other objects and advantages, etc., may be combined with the following detailed description and the appended claims. Figure 1 However, it should be understood that the drawings are only for illustration and description and are not intended to limit the present invention.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more completely understand the present invention, the following description is provided below in conjunction with the accompanying drawings, in which:

[0035] Figure 1 is a schematic diagram of one embodiment of a method for preparing an absorbent composite using a calendaring roller;

[0036] Figure 2 is a schematic diagram of another embodiment of a method for preparing an absorbent composite using a calendaring roller;

[0037] Figure 3 Using other energy Figure 1 A schematic diagram of the method shown;

[0038] Figure 4 Ultrasonic bonding technology is used to replace the calendering roller. Figure 1 A variation of the method shown;

[0039] Figure 5 Ultrasonic bonding technology is used to replace the calendering roller. Figure 2 A variation of the method shown;

[0040] Figure 6 A variety of potential bonding patterns that can be used in the method and absorbent article are shown;

[0041] Figure 7 is a schematic cross-sectional view of a bag formed by the method and used in an absorbent article;

[0042] Figure 8 is a perspective view of a disposable absorbent article embodying an absorbent composite;

[0043] Fig. 9 In flat and unfolded condition Figure 8 A top plan view of a disposable absorbent article;

[0044] Fig.10 yes Figure 8 A cross-sectional view of a disposable product;

[0045] Fig.11 is a partial cross-sectional view of an absorbent core utilizing an absorbent composite and employed by an absorbent article;

[0046] Fig.12 is a partial cross-sectional view of an absorbent core utilizing an alternative embodiment of the absorbent composite of the present invention and employed by an alternative absorbent article;

[0047] Fig.13 is a cross-sectional view of an absorbent article employing an absorbent composite in a leg cuff;

[0048] Fig.14 is a cross-sectional view of an absorbent article employing a saturable absorbent composite in a leg cuff;

[0049] Figures 15A-15D is a simplified schematic diagram of an absorbent composite of the present invention, which specifically focuses on the arrangement of absorbent particle aggregates in the composite;

[0050] Fig.16A is a simplified schematic diagram of a prior art SAP sandwich;

[0051] Fig. 16B is a simplified schematic diagram of the SAP structure (sandwich) of the present invention;

[0052] Figures 17A-17D is a simplified schematic diagram of a cross section characterizing bag and fluid properties of a bag arrangement according to the present invention;

[0053] Fig.18A is a simplified schematic diagram of a method for preparing the absorbent composite of the present invention;

[0054] Figures 18B-18C yes Fig.18A schematic diagrams or photographs of exemplary components of the described methods;

[0055] Fig.19 Is a representative Fig.18A A simplified cross-sectional view of an absorbent composite of the method;

[0056] Fig. 20A is a simplified cross-sectional view through the transverse centerline of a disposable absorbent article employing an absorbent core laminate according to a preferred embodiment of the present invention;

[0057] Fig. 20Bis a simplified cross-sectional view through the longitudinal centerline of a disposable absorbent article employing an absorbent core laminate according to a preferred embodiment of the present invention;

[0058] Fig. 20C yes Fig. 20A and 20B A simplified cross-sectional view of an absorbent composite in an absorbent core laminate;

[0059] Fig.21 is a cross-sectional view of an absorbent core stack according to one embodiment of the present invention;

[0060] Figures 22A-22C Is manufacturing Fig.21 Cross-sectional views of various stages of the laminate;

[0061] Fig.23 is a top perspective view of a raised absorbent core stack according to one embodiment of the present invention;

[0062] Fig.24 is a plan view of an exemplary absorbent core laminate employing bonding points according to one embodiment of the present invention;

[0063] Fig.25 is a plan view of an absorbent core laminate according to another embodiment of the present invention;

[0064] Fig.26 is a cross-sectional view of an absorbent core laminate according to another embodiment of the present invention;

[0065] Fig. 27 is a simplified schematic diagram of stages in the manufacture of an absorbent core laminate according to one embodiment of the present invention;

[0066] Fig.28 is a plan view of a disposable absorbent article employing an absorbent core laminate according to a preferred embodiment of the present invention;

[0067] Fig.29 is a simplified schematic diagram of a cross-sectional view of an absorbent composite according to a preferred embodiment of the present invention; and

[0068] Fig.30 is a simplified schematic representation of a partial cross-section of a bulky nonwoven layer incorporated in the absorbent composite of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0069] After reading the drawings and detailed description provided herein, it will be appreciated by those of ordinary skill in the art that the absorbent composites prepared according to the present invention can be used for disposable absorbent articles, and more specifically, for disposable absorbent articles, such as diapers, training pants or other incontinence products. Therefore, the present invention is not limited to the structures and methods described and shown herein, although the following description specifically relates to absorbent composites for disposable diapers. The terms "absorbent articles" or "absorbent garments" associated with the present invention include various types of disposable articles and garments that are placed against or proximate to the wearer's body to absorb and hold various body excreta, body fluids or biological fluids.

[0070] In order to obtain a better understanding of the specific contributions or improvements brought by the present invention, reference may first be made to the improvements of the earlier disclosed U.S. Patent No. 8,148,598. Figure 1-14 These early improvements are described in . In addition to being used as background knowledge in the art, some of the teachings and inspirations therein are transformed into certain specific embodiments of the present invention (which will become obvious to those skilled in the relevant art under the disclosure of the present invention).

[0071] exist Figure 1 1, fabric 125 is shown as being dispensed from roll 120 and carried along a production line on conveyor belt 100. Fabric 125 may be a thermoplastic material, which may be a woven fabric, a nonwoven fabric, a film, or a combination thereof. Fabric 125 is secured to conveyor belt 100 by vacuum system 110. Vacuum system 110 is used to conform fabric 125 to conveyor belt 100.

[0072] In one embodiment, the conveyor belt 100 has a depression that forms a cup in the fabric 125 when the fabric is pulled away from the surface of the conveyor belt 100. The surface of the conveyor belt 100 is not limited to a structure that forms a cup in the fabric, but instead can be composed of a variety of different surface shapes and sizes. Examples include ridges, raised shapes, and holes. In addition, the surface shape can be evenly or unevenly distributed over the length and width of the conveyor belt. Alternatively, the conveyor belt 100 can be flat. In applications where the conveyor belt 100 has holes or other similar structures, the depth of the pocket formed in the fabric 125 can vary depending on the force of the vacuum system 100, the elasticity of the fabric 125, or a combination thereof. In addition, heat can be used to increase the elasticity of the fabric 125 when the fabric is pulled away from the surface of the conveyor belt 100. The fabric can be heated by a heated conveyor belt or any other means known in the art. The vacuum 110 can be applied uniformly or at selected locations on the surface of the conveyor belt 100. For example, in a configuration where the surface of the conveyor belt 100 has depressions, the vacuum can be applied only at the depressions.

[0073] The SAP particles 135 are then deposited on the fabric 125 by the SAP disperser 130. The SAP disperser 130 can be configured to place the SAP particles at their desired locations on the first fabric, or can be configured to deposit the SAP particles only on the first fabric, where the SAP particles are placed by another means. It will be appreciated by those skilled in the art that multiple SAP dispersers 130 can be used. The SAP particles 135 can be deposited, placed, or deposited and placed on the fabric 125 by wind or other known methods. Alternatively, Figure 1 The conveyor shown can be reversed so that the vacuum system 110 applies suction from above. In this configuration, the fabric 125 is carried on a supply of SAP particles 135, and the SAP particles are maintained on the surface of the fabric 125 by the vacuum system 110. In other embodiments, the SAP disperser 130 may contain skin care particles, such as ion exchange resins, deodorants, antimicrobial agents, adhesive particles or other beneficial particles. In addition, although the preferred embodiments relate to SAP particles, the methods described herein can be used for any combination of the above particles, including combinations that do not contain SAP. Alternatively, separate dispersers, preferably placed along the production line (not shown), can be used to deposit different types of particles, for example, skin care particles.

[0074] According to a plurality of alternative methods, SAP particles 135 are placed and concentrated on fabric 125. In one embodiment, vacuum system 110 and fabric 125 can be caused to make vacuum system 110 pull SAP particles from the surface of fabric 125 evenly or in a specific area. In another embodiment, the shape of fabric 125 introduces SAP particles 135 into position. For example, when fabric 125 is formed to form a bag, SAP particles 135 are rolled into the bag by vacuum system 110, vibration of conveyor belt, wind, angle of conveyor belt or a combination thereof. Alternatively, SAP disperser 130 can be placed and controlled to strategically disperse SAP particles 135 on the surface of fabric 125, and the strategic placement includes but is not limited to alignment or misalignment with the machine direction, offset or random. In addition, SAP can be placed so that there is an area without SAP. In addition, SAP particles can be placed using adhesives, such as by applying adhesives to specific positions on the surface, depositing SAP particles on the surface. In addition, SAP particles can be placed on two fabrics 125 and 155 at the same time.

[0075] Once the SAP particles have been deposited and positioned on fabric 125, a second fabric 155 is introduced into the production line from roll 150. Second fabric 155 may be selected from a variety of materials including spunbond thermoplastics or similar woven or nonwoven materials, films, or combinations thereof.

[0076] Applying the binder 145 to the SAP particles 135 can be done in a variety of ways. Figure 1An adhesive 145 is shown applied to a fabric 155. Alternatively, the adhesive 145 may be applied to the fabric 125 and the SAP particles 135, to the fabric 125 before the SAP particles 135 are deposited on the fabric 125, or directly to the SAP particles before they are deposited on the fabric 125. In another embodiment, the adhesive 145 is applied at the point where the fabrics 125 and 155 are joined together. In another embodiment, multiple layers of adhesive are applied. For example, the adhesive 145 may be applied to the fabric 125 before the SAP particles are deposited, or to the SAP particles 135 after they have been placed, to the fabric 155, or a combination thereof. Alternatively or in addition to the above embodiments, the adhesive particles may also be mixed with the SAP particles 135. In addition, the adhesive may be applied uniformly, randomly, or in a specific pattern, depending on the desired absorption properties of the finished composite.

[0077] The adhesive can be applied according to a variety of techniques known to those skilled in the art. For example, the adhesive can be sprayed, rolled or spun onto the surface of the fabric 155. The adhesive can be hydrophobic, hydrophilic, biodegradable, bioderived adhesive or a combination thereof. The preferred adhesive is hydrophobic. The concentration of the adhesive in the coating is 1 to 100 grams per square meter ("GSM"). Preferably, the concentration is 5 to 75 GSM. In a preferred embodiment, the concentration is 12 to 50 GSM. In addition, sufficient adhesive should be applied to cover at least 25% of the target area.

[0078] Fabrics 125 and 155 are then bonded together. Figure 1 A heat bonding system using calendar rolls 160 and 170 is shown. However, other bonding systems / methods may be used. For example, Figure 4 and 5 The adhesive 145 holds the SAP particles 135 in a relatively fixed position with respect to the fabric during and after the bonding process. The bonding pattern may be aligned with the distribution of the SAP particles 135. Alternatively, the bonding pattern may not be aligned with the distribution of the SAP particles 135. In such embodiments, the bonding apparatus may be adapted to push the SAP particles 135 to one side or bond to the SAP particles 135 prior to bonding. These embodiments eliminate the need to synchronize the bonding points with the distribution of the SAP particles.

[0079] Fabrics 155 and 125 are shown as two materials. However, those skilled in the art understand that the fabrics can actually be parts of the same material. In this configuration, the entire fabric is folded to cover the SAP particles. Alternatively, the edges of fabric 125 can be folded before using the second fabric 155. In embodiments where fabrics 125 and 155 are separate, fabrics 125 and 155 can be the same or different materials. In addition, fabric 155 can be cut to cover specific areas of fabric 125, such as the center area.

[0080] Once the webs have been bonded together, the absorbent composite 195 is collected on a rewinder 200 .

[0081] exist Figure 2 In the method shown, a fabric 125 is transported along a conveyor belt 100. A thin coating of adhesive 145 is applied to the fabric 125 as the fabric 125 is transported along the conveyor belt 100. Figure 1 As shown in the method of FIG. 1 , the adhesive can be applied uniformly, randomly, or in a specific pattern, depending on the desired absorption properties of the finished composite. Although the adhesive 145 is shown to be applied before the SAP particles 135 are deposited, other embodiments are contemplated. For example, the adhesive can be applied in accordance with Figure 1 The described embodiments apply an adhesive.

[0082] After applying the adhesive, SAP particles 135 are deposited and placed on the fabric 125. The SAP particles 135 can be deposited directly on the fabric 125, such as Figure 2 As shown, or indirectly deposited on the fabric 125, such as by wind blowing the SAP particles onto the fabric 125. The weight of the SAP particles helps to fix the fabric 125 to the conveyor belt 100. In addition, the SAP particles can be Figure 1 Place in a similar manner as shown.

[0083] A second fabric 155 is then fed from roll 150 to the production line. The second fabric is placed to cover the SAP particles 135. The adhesive 145 prevents the SAP particles from moving freely between the two fabrics. The resulting sandwich structure is then transported to calendar rolls for thermal bonding. Figure 1 As described above, the bonding pattern may or may not be aligned with the SAP particles 135. The absorbent composite 195 is then collected by a rewinder 200. Figure 1 As shown, fabrics 125 and 155 can be parts of a single piece. Alternatively, the fabrics can Figure 1 In another embodiment, the fabric 125 may be coated with an adhesive and pressed onto a supply of SAP particles.

[0084] Figure 3 and Figure 1 and Figure 2 Similar, except that an energy source 900, such as an oven or microwave generator, is placed along the assembly line. The energy source applies heat and / or radiation 910, which can be used to melt the thermoplastic binder. The heat can also be adjusted to melt specific types of particles or fibers, specific portions of the fibers, or only the outer layer of the particles / binder.

[0085] Figure 4 and Figure 5 and Figure 1 and Figure 2Similar, except ultrasonic bonding is used to bond the fabric together. Figure 4 and Figure 5 Ultrasonic bonding systems (210a and 210b) are shown. Figure 1-5 Different embodiments of the new method are shown and aspects of the various aspects can preferably be combined as desired. However, important for all combinations is the amount of adhesive 145, binder particles or a combination thereof applied to the SAP particles 135 and the strength of the bond. Figure 1 As shown, the optimum concentration of adhesive is 12 to 50 GSM, although other concentrations are acceptable. In all embodiments, it is important that the concentration of adhesive 145 is high enough to prevent the migration of SAP particles 135. However, the concentration should not be so high that it covers the SAP particles 135 and reduces SAP swelling. The adhesive should only prevent the migration of enough SAP particles 135 to ensure uniform absorbency. Although not shown, it will be understood by those skilled in the art that Figure 3 The energy source 900 shown may also be used in Figure 2 , 4 and the structure shown in 5.

[0086] Figure 6 (a) through (q) show various bonding patterns considered for the method. The bonding patterns may completely cover an area, partially cover an area, or provide localized bonding areas. Lines and dots represent bonding sites. Solid lines represent bonding lines. Bonding lines may form open shapes or closed shapes, as found in examples (a) and (c), which show continuous solid lines that completely enclose pockets of SAP particles 135, or as in example (g), separating different areas of the absorbent composite. As found in examples (b) and (m), the dashed lines are discontinuous bonding patterns that do not completely enclose pockets of SAP particles 135. In these constructions, migration of dry SAP particles is prevented by the adhesive and the continuous or discontinuous bonding patterns. A discontinuous bonding pattern may replace a continuous bonding pattern, and vice versa. In addition, although Figure 6 Continuous or discontinuous bonding patterns are shown, and combinations of discontinuous and continuous bonding patterns may be used.

[0087] Figure 7 A partial cross-section of an absorbent composite 195 is shown. Figure 7 It is shown how bonds 192 are used to separate pockets of SAP particles 135. As indicated by the bond pattern, the SAP particles 135 may be completely enclosed in pockets defined by the bond pattern, partially enclosed in pockets defined by the bond pattern, or merely blocked by the bond pattern. Blocked in this context means that the SAP particles 135 cannot move directly from one area of ​​the core to another, but instead must move around the bond site.

[0088] It should be noted that multiple functions or preferred properties can be obtained in the absorbent composite by varying the amount of SAP particles, the type and amount of fabric used, the composition variables (such as the ratio of SAP to adhesive), and applying the adhesive composite at various locations in the article. Such manufacturing and design techniques can be incorporated into the structural design and method of the present invention.

[0089] In addition, those skilled in the art will appreciate that the method for constructing the above-described single absorbent composite can be modified to produce multiple, stacked absorbent composites. In structures comprising multiple layers, the layers can be sheets of absorbent composite 195 that are stacked together to form a single structure, or alternating layers of fabric and SAP particles that form a single structure. Those skilled in the art will appreciate that the absorbent composite can be formed by applying an adhesive ( Figure 1 ), a second layer of SAP particles 135 and a third fabric (not shown) are applied to achieve alternating layers. Similarly, other layers may be added, limited only by the maximum thickness applicable to the bonding method.

[0090] The SAP particles 135 may be coated with a mutually soluble hydrophobic material. The coating acts as a barrier or membrane that initially slows liquid uptake, thereby conserving SAP capacity for additional or secondary discharges. In this regard, the coating evens out the absorption rate between discharges. Figure 1-5 In the method shown, the coating may be applied before, after, or simultaneously with the application of the adhesive 145. Alternatively, the adhesive may be mixed with the coating material.

[0091] In one embodiment, a light coating of mineral oil is applied over the SAP particles 135. This coating slows the initial uptake of the SAP particles and allows the liquid to have more time to spread out in the article. Preferably, the mineral oil is applied at a concentration of about 0.00001 g / g SAP to about 0.1 g / g SAP (depending on the specific product design). Alternatively, the mineral oil may be applied in specific target areas. In this way, the received liquid is encouraged to initially disperse into uncoated areas before the coated areas activate and begin to swell.

[0092] The absorbent composites made by the above method can be used in disposable dispersing articles or as one or more components of disposable dispersing articles. The components of the absorbent article include a back layer, a top layer, an absorbent core, a containment wall or envelope (including leg gathers), a back layer / absorbent core composite, a top layer / absorbent composite, and combinations thereof. This type of construction is described in more detail below.

[0093] Figure 81 is a perspective view of a disposable absorbent article in the form of a diaper 10. The diaper 10 includes a top layer 50, a back layer 60, and an absorbent core (not shown). The diaper also includes an upright barrier cuff 34 that extends longitudinally along the diaper and is elastic to conform to the wearer's hips. In addition, the diaper includes an elastic band 52 and a fastening element 26. In use, the elements 26 extend and engage the corresponding opposite side ends of the diaper to secure the diaper on the wearer.

[0094] Fig. 9 Shown in generally flat and unfolded configuration Figure 8 The composite web structure of the diaper 10 of the present invention is shown in FIG. 1. As will be described in detail below, the web structure is subsequently trimmed, folded, sealed, forged and / or otherwise operated to form the diaper 10 in a finished or final form. To facilitate the description of the diaper 10, reference is made to a longitudinally extending axis AA, a transversely extending central axis BB, a pair of longitudinally extending edges 90 and a pair of end edges 92 (which extend between the side edges 90) for description. Along the longitudinal axis AA, the diaper 10 includes a first end region or front waist region 12, a second end region or rear waist region 14, and a crotch region 16 disposed therebetween. The front waist region 12 and the rear waist region 14 are each characterized by a pair of ear regions or ears 18, which are located on either side of the central body portion 20 and extend laterally from the side edges 90. A fastening structure 26 (e.g., a conventional strip fastener) is fixed to each ear 18 along the rear waist region 14 of the diaper 10.

[0095] When the diaper 10 is worn around the waist, the front waist region 12 fits adjacent to the front waist area of ​​the wearer, the back waist region 14 fits adjacent to the back waist area, and the crotch region 16 fits around and below the crotch area. To secure the diaper 10 to the wearer, the ears 18 of the back waist region 14 are around the wearer's waist and forward and aligned with the ears 18 of the front waist region 12. The securing surface may be located on or provided by the inner or outer surface of the front waist region 12. Alternatively, the fasteners 26 may be located on the ears 18 of the front waist region 12 and may be secured to the ears 18 of the back waist region 14.

[0096] Fig.10 yes Figure 8 and Fig. 9 195. A suitable diaper structure generally employs at least three layers. The three layers include a backing layer 60, an absorbent core 46, and a top layer 50. The diaper structure may or may not contain a pair of containment walls or leg cuffs 34 disposed upwardly from the top layer 50, and is preferably equipped with at least one or more longitudinally spaced elastic elements 38. It will be shown below that any of these diaper elements or combinations of these elements will be constructed with an absorbent composite 195. In addition, a collection layer 48 may be added to improve performance.

[0097] Back layer

[0098] As described above, the diaper 10 employs a backing layer 60 that covers the core 46 and preferably extends over the core 46 toward the side edges 90 and end edges 92 of the diaper 10. In one aspect of the invention, the backing layer 60 is constructed from a single layer of material of the absorbent composite 195. In this construction, the fabric 125 is placed as the outer surface of the backing layer 60.

[0099] In addition, alternative structures can be used for the gel barrier. For applications using a gel barrier, the back layer of the disposable absorbent article of the present invention is thinner and provides improved flexibility. When dry, the back layer is soft and breathable, but when wet, a thin gel barrier layer is formed (i.e., on the inner surface of the back layer), which makes the back layer substantially impermeable to liquids. The gel barrier layer is formed by swelling of the SAP particles 135.

[0100] Top floor

[0101] Similarly, the absorbent composite 195 can be used in conjunction with or as the top layer of an absorbent garment. The top layer 50 is preferably soft, compliant, shows good permeability and reduced tendency to rewet from previous liquid materials. When wearing the diaper 10, the top layer 50 is close to the skin of the wearer. In this way, this top layer 50 allows body excreta to quickly penetrate to flow to the core 46 faster, but does not allow this excretion flow to return through the top layer 50. The top layer 50 can be made of any of a wide range of liquid and vapor permeable hydrophilic materials. The surface of the top layer can be treated with a surfactant to promote liquid to pass therethrough, especially in the central area of ​​the top layer on the core and the inner surface of the core. The top layer can also be coated with a material (e.g., aloe) that has an anti-rash or rash-reducing property.

[0102] In one embodiment, the topsheet 50 is formed from an absorbent composite 195 that covers substantially the entire area of ​​the disposable absorbent article 10, including substantially all of the front waist region 12, the back waist region 14, and the crotch region 16. In addition, the ear layers of the interior region 18 are formed from the same single topsheet material and, thus, can be integrally formed with the topsheet 50 as lateral extensions of the topsheet material. Alternatively, the topsheet 50 can be formed from a plurality of different materials that vary across the width of the topsheet 50. Such a multi-piece design can produce preferred properties and different regions of the topsheet.

[0103] Absorbent core

[0104] Additionally or alternatively to the above-described embodiments, the absorbent core of a disposable absorbent article may be constructed from an absorbent composite 195, a laminate of layers (not shown) of absorbent composite 195, or multiple layers of SAP particles 135 and fabric. Fig.11 and 12Cross-sectional views of alternating layers of SAP particles 135 and fabric are shown, forming multilayer absorbent composites 700 and 900, respectively. As shown in these figures, the core 46 can be composed of different layers of SAP particles 135 (710 and 910). These layers can be uniform or non-uniform, depending on the intended application. In a non-uniform multilayer absorbent composite 900, the concentration of SAP particles 135 can vary within a given layer, between layers, or a combination thereof.

[0105] Fig.11 A composite structure 700 is shown in which SAP particle layers 710 and fabric layers 720 alternate to form a complete composite structure 700. Layered designs can also be constructed by combining absorbent composite sheets together during the manufacturing process, folding an entire sheet of absorbent composite, or using multiple layers to construct the absorbent composite. In folding applications, the composite fold can be a C-fold, a Z-fold, a V-fold, a W-fold, or a combination thereof. In addition, the fold can be open, closed, or overlapping.

[0106] Fig.12 A multilayer absorbent composite 900 is shown. Fig.12 As shown, high concentration areas of SAP particles 910 can be strategically placed to provide additional absorbency in specific areas such as the crotch of an absorbent article. Those skilled in the art will appreciate that high concentration areas can be offset to control the amount and direction of liquid penetration. In addition, a layer with high concentration areas can be combined with a layer of a substantially uniform layer. Alternatively, a high SAP concentration area can be formed by placing a multi-layer absorbent core.

[0107] The core may be arranged to extend substantially the entire length and / or width of the disposable absorbent article. Preferably, however, the core is deposited or concentrated in the crotch region of the article. In various embodiments, the core extends to the edge of the article and the SAP particles 135 are concentrated in the crotch region or other target area of ​​the article. In another embodiment, the article may be a combination of SAP particles, skin care particles such as ion exchange resins, deodorants, antimicrobial agents, binder particles, or other beneficial particles.

[0108] containment wall

[0109] Reference now Fig.13 and Fig.14 , disposable absorbent article 10 uses a pair of containment walls or envelopes 34, which employ absorbent composites 195. Each containment wall 34 is a longitudinally extending wall structure, preferably placed on each side of core 46 and laterally spaced from the longitudinal center. For example, the longitudinal ends of wall 34 may be connected to the top layer of front waist region 12 and back waist region 14. Preferably, the ends of containment wall 34 are nailed inwardly downwardly and connected to the net structure by adhesive. This structure effectively biases containment wall 34 inwardly and is generally considered to make containment wall 34 show improved leakage-proof properties.

[0110] Fig.13 A cross-sectional view of a diaper 10 is provided. The diaper 10 includes a backing layer 60, an absorbent core 46, an acquisition layer 48, and a top layer 50. Fig.13 As shown, the core is an absorbent composite 195. The diaper 10 also includes a pair of containment walls or envelopes 34 formed by folding the top layer 50 and wrapping it around the ends of the absorbent composite 195. Alternatively, the absorbent composite 195 in the envelope 34 may be distinct from the absorbent core 46.

[0111] Preferably, the containment wall 34 is provided with an elastic element 38, which extends substantially along the length of the containment wall 34. In common applications, the elastic element 38 is placed within the containment wall 34, preferably at the top of the containment wall 34 while being glued to the containment wall at least at its ends in a stretched state. When released or allowed to relax, the elastic element 38 retracts inwardly. When the article 10 is worn, the function of the elastic element 38 is to contract the containment wall 34 around the thighs and buttocks of the user in a manner that creates a seal between the article 10, the buttocks and the thighs. The core 46 can be a single piece or a multi-layer absorbent composite 195, as described above.

[0112] Fig.13 The configuration of the containment wall 34 when soft and dry is shown. Fig.14 In another aspect, the containment wall is shown after wetting, wherein the absorbent composite has swelled to place the containment wall 34 in an elastic upright position. Unlike conventional leg cuffs of the prior art, the elastic upright containment wall 34 resists flattening (e.g., when the wearer sits down), thereby ensuring leak prevention (especially bursting), liquefied internal movement, and rapid drainage of urine.

[0113] Optional layer

[0114] Disposable absorbent articles may employ other layers, including an acquisition layer or buffer layer 48, preferably positioned between the topsheet and the core (e.g., Fig.10 ). One function of such an acquisition layer is to spread or disperse the liquid flow so that the liquid is more evenly distributed over the core surface. This serves to slow the flow so that the liquid has enough time to be absorbed by the core. The acquisition layer also serves to prevent the core from being locally saturated while the bulk of the rest of the core does not absorb any liquid.

[0115] bring

[0116] Disposable absorbent articles must be secured to the wearer. This is most important for diapers, which are not pulled upward by the wearer like training pants or incontinence briefs, but must be fastened around the wearer. The securing elements conform to the elastic elements by creating a quasi-sealing effect between the wearer and the waistband and leg cuffs so that liquid is contained within the article and then absorbed; in other words, so that it does not leak through the gap between the wearer and the edge of the article. The securing elements can be adhesives, mechanical fastening hook and loop structures, or any conceivable cord that secures one end of the article to the longitudinally opposite end. The securing elements can also be co-bonded so that they adhere to each other but not to other materials.

[0117] In the example shown in the drawings (see e.g. Fig.10 ), the article 10 is secured to the wearer by means of belt fasteners 26, which are then permanently secured to (e.g., sewn directly to) the backing layer 60. The belt fasteners 26 are in contact with the laterally opposed ears 22 extending from the backing layer, where they are held in place by the adhesive applied to the fasteners 26. Alternatively, the article 10 may be a training pant, a pull-on diaper, etc. In this configuration, the article 10 may or may not have belt fasteners 26.

[0118] belt

[0119] The waistband using elastic elements 52 is prevented along the lateral portion of the article 10 so that when worn, the waistband is located at the waist of the wearer. Generally speaking, the waistband preferably creates a quasi-seal (lateral elastic elements 52) to the waist so that liquid waste does not leak from the area between the waist elastic elements and the waist of the wearer. Quasi-seal is important because although liquid may eventually be absorbed by the filling material, the wearer's liquid impact may exceed the absorption rate capacity of the filling material. Therefore, the waistband contains liquid when absorbing. Second, the waistband may have the ability to absorb liquid (see, for example, U.S. Patent No. 5,601,544, which is incorporated herein by reference).

[0120] Aggregate (and embossing) patterns and material selection for lint-free absorbent composites

[0121] Figures 15A-15D A simplified schematic diagram of an absorbent composite 510 having a particularly preferred arrangement of absorbent particle aggregates 512 according to the present invention (like elements are represented by like numbers). Fig.15A , each aggregate on the absorbent composite 510 is represented by a diamond closure 514 in the pattern. In a preferred embodiment, SAP is used as the absorbent particle in the aggregate. In addition, Figures 15A-15DThe SAP aggregates in each are preferably held in place and stabilized by the physical enclosure or containment provided by the engagement of a first fabric with a second fabric, the first fabric being generally deposited above the SAP aggregates and the second fabric being generally deposited below the SAP aggregates. Fig.15A In other views of the present invention, diamond-shaped elements represent the outline of a container or bag and, in certain embodiments, reflect the joining of a top fabric to a bottom fabric.

[0122] As mentioned above, the absorption performance of SAP may be affected by the size and structure of the container. As SAP becomes more and more saturated, its permeability decreases. Due to the high level of water already contained in the SAP particles, water cannot pass through the SAP particles, and eventually SAP can completely stop other fluids from passing through. This is called gel barrier. Similarly, as SAP becomes more and more saturated, it swells and its volume increases. By limiting SAP in a small container of fixed volume, the swelling of SAP may be limited to prevent it from reaching the highest saturation level (and eventually, stopping SAP from reaching the lowest level of permeability). The degree to which SAP particles are limited depends on multiple factors, including: the nature and size of the container, the size and frequency of any fractures in the container (for example, along the sidewall), the amount of SAP deposited in the container and the amount of fluid absorbed by SAP. In addition, the performance properties of SAP are affected by its saturation. Specifically, when SAP becomes completely saturated from drying, the absorption composite properties, such as permeability, absorption rate, capillary pressure (generated from the interstitial space in the composite), will change significantly. According to the method of the present invention, the target or optimal performance of the SAP can be achieved by changing the size of the container and / or the SAP concentration to physically constrain the swelling of the SAP and display the maximum saturation point of the SAP. By incorporating these physical characteristics, it is possible to achieve a preferred level of permeability or a preferred absorption property in the target area of ​​the absorbent core. Therefore, by controlling the two variables of the bag size and the amount of SAP in the bag, the minimum permeability of the container or bag can be "set". It is possible to prevent the bags in some areas of the diaper from gel blocking and the permeability of the core in this area may be optimized. It is also possible to establish a gradient of bag size to obtain maximum flow and utilization of the absorbent core. This gradient may radiate from the target area to the end or side of the diaper.

[0123] Various arrangements of containers or bags also promote utilization of the SAP and core and prevent fluid from bypassing the container. Ideally, the fluid should leak or flow between containers when the SAP reaches a maximum saturation level (which is set by the properties of the SAP or the volume of the bag expansion). Applicants contemplate that in some of the aforementioned composite or bag arrangements (see Figure 6), there may be a tendency for fluid to leak between bags. This is by the fluid running along the channel formed by the nipple and not entering the core. To mitigate this tendency, the arrangement or pattern of the containers is preferably those that minimize or eliminate the short straight paths of fluid flow from the center of the core to the side edge (end edge) of the core (as can be established along the nipple). To illustrate, diamond-shaped containers or bags are better than square or rectangular containers because the diagonal lines or channels formed by diamond-shaped containers are longer and more circuitous. A circle is also effective if packaged in a way that does not show a channel that flows quickly to the edge. In a more preferred arrangement, the fluid flow is forced to change direction once or multiple times before flowing to the side of the diaper.

[0124] It is desirable for an absorbent core for a baby diaper or adult incontinence product to absorb fluid quickly, in anatomically aligned areas of the core, absorb all of the fluid without leaking to the sides or edges of the product, and retain the fluid without wetting the user's skin, especially under pressure created by the user's weight. The present invention accomplishes this by providing core areas with different performance parameters defined by the size of the container holding the SAP and the arrangement of the container. Thus, the core can be designed to achieve optimized performance characteristics by varying the size of the pockets and / or the concentration of the SAP within the pockets.

[0125] In some arrangements shown herein, design features are combined to provide a core that is unlikely to leak, quickly absorbs moisture and provides a dry, comfortable feel to the user. In the crotch region of the core, the container size and SAP load are optimized to provide an open structure with high permeability, resulting in rapid collection or distribution of fluids away from the failure point and the user's skin. Due to the physical constraints of the container that limits further swelling, permeability can be maintained even when the SAP swells. This allows the fluid to be spread more efficiently in the region, further limiting the target area (crotch region) and resulting in better performance and utilization of the absorbent core. In the region away from the crotch region, this region is close to and exceeds the periphery of the core, reducing permeability to delay fluid. Increase the absorptive capacity by a larger bag, which makes the SAP swell more completely and accommodates more fluid.

[0126] exist Fig.15AIn the core 510, there are large diamond-shaped containers or bags 514 for absorbing particle aggregates 522 in areas anatomically aligned with the failure points. These containers then gradually reduce in size toward the sides and front and rear edges or edges of the core 510. There are three different container areas. In the crotch area "A", large diamond-shaped bags are provided. Adjacent and surrounding the crotch area is the middle area "B", the size of its bags is smaller than those in the crotch area (A). In addition, the presence of smaller bags in this middle area (B) breaks the potential fluid flow around the SAP aggregate and along the embossed line. As mentioned above, the presence of this barrier to the direct escape of fluid to the side edges prevents leakage and promotes the utilization of SAP aggregates. Finally, the third area "C" of bags exists near each end edge of the core 510, in which there are smaller SAP aggregate bags.

[0127] Fig. 15B A second exemplary arrangement of SAP aggregates 522 and pockets 514 is shown. In this embodiment, small diamond-shaped pockets 522 are deposited in areas that anatomically align with the fluid failure points. The pockets then gradually increase in size in areas toward the side and front and back edges of the core. Fig.15A and Fig. 15B ) provides an alternative way to construct flow gradients and control liquid failures. Fig.15A The pocket arrangement and absorbent composite in the embodiment of the present invention may provide a central region with initially greater capacity, but which over time will redistribute fluid within its void volume, or from subsequent fluid failure into smaller adjacent pockets or chambers. Fig. 15B The central area can initially be equipped with a smaller volume, which will cause the liquid to move to the larger chamber. It is also possible to generate surface geometry in such a way that leakage from the sides and ends of the diaper will create a "dam" that intercepts and absorbs the surface flow.

[0128] Fig. 15C and 15D An alternative arrangement is provided in which circular pockets of SAP aggregate are employed. Fig. 15C In the embodiment of the present invention, there is a circular pocket in the area anatomically aligned with the failure point. The size of the pocket 534 gradually decreases towards the side edges and the leading and trailing edges of the core 530. The pattern is similar to Fig.15A Similar to the one used in , but with round bags instead of diamond-shaped bags. Many Fig.15A The permutation features in are transformed into Fig. 15C in design.

[0129] However, unlike diamond-shaped bags, it is not possible to create a perfectly close-packed pattern of circular bags and the resulting spacing between circular bags can be arranged in a variety of ways. It is contemplated that the spacing between circular bags can be fully convex (i.e., with large convex thermal bonding areas between bags), partially convex, or non-convex. The spacing can also contain SAP or not contain SAP.

[0130] Fig.15D Another embodiment of the present invention is shown, which has a similar Fig. 15B In this embodiment, small circular pockets 544 are provided in areas anatomically aligned with fluid failure points. The pockets 544 gradually increase in size in areas toward the side and front and rear edges of the core. Likewise, the spacing between pockets 544 can be utilized in a variety of ways as described above.

[0131] It should be noted that the arrangement and raised pattern are not limited to using diamond-shaped or circular pockets. Other shapes can be considered. Some arrangements can even use different pocket shapes in the same pattern.

[0132] The table below summarizes the properties of different bag sizes, assuming the SAP concentration remains uniform in the core.

[0133] Table 1. Summary of performance by product size and SAP saturation

[0134]

[0135]

[0136] Structures, methods and systems for absorbing particle construction and / or stabilization

[0137] In providing other variations of the absorbent composite of the present invention, one or more nonwoven webs used in the previous embodiments are replaced with a more open structure. Examples of such nonwovens include carded PET webs, air-through bonded nonwovens, resin-bonded nonwovens, and non-absorbent air-laid structures. Materials known as acquisition and distribution layers (ADLs) are included in this list of suitable materials. The resulting structure provides an alternative means of accommodating absorbent particles, more specifically accommodating absorbent particles within a fiber network but without an absorbent matrix of fibers (i.e., without slurry). This structure promotes the distribution of SAP within the fiber network provided by the nonwoven web layer. In addition, the distribution of SAP particles in a more open network provides a mechanism for further stabilizing SAP within the nonwoven simply by entanglement of the particles within the fiber network.

[0138] Fig.16A The composite structure is shown. The composite uses nonwoven fabric as the bottom layer (NW1) and the top layer (NW2) to sandwich a SAP material layer (SAP). Fig. 16BAn alternative structure is shown in which a bulky nonwoven ("bulky" NW1) is used as a base layer. The bulky nonwoven layer NW1 provides fibers that stretch outward and entangle the SAP particles. This entanglement with the fibers in a more open material leads to the stabilization of the SAP in the absorbent composite. During the manufacturing process, the SAP particles applied to the sheet or web of the bulky nonwoven can be controlled to promote penetration into the fiber network of the more open nonwoven web. The SAP particles prevent the maximum effect of gravity on the particles when on the web, which may be sufficient to promote the desired penetration. Technologies such as vacuum or vibration can be used to further enhance the penetration of the SAP particles into the open fiber network.

[0139] The stabilization of the SAP prevents the material from moving during processing, storage and use. In an exemplary embodiment, as described above, in addition to using a container or bag of adhesive and SAP aggregates, the absorbent composite or core can adopt a "lofty nonwoven" structure (such as Fig. 16B ) to stabilize SAP.

[0140] It should also be noted that a more open nonwoven material can provide other performance characteristics. These characteristics include faster acquisition of fluid and improved dryness (rewetting) for the user. Likewise, the absorbent matrix will feel fluffier (more spongy) than a "flat" nonwoven web and will provide a softer composite. This results in greater comfort for the user and a better fit around the contours of the user's body, resulting in a reduced chance of leaks.

[0141] Reference now Figures 17A-17B The exemplary absorbent composite preferably provides a top layer of a "lofty" nonwoven. Fig.15A Simplified cross-section of the composite. Since the substrate used to contain the SAP is an open structure nonwoven fabric characterized by large pores (about 2000 microns). The embossing will set and stabilize the local pore structure of the fluffy elastic fiber web substrate. The area where the embossed pattern is small (using a small container) Fig.17A ) produced a similar pattern to that with a larger imprint group ( Fig. 17B ) area (which creates larger pores ( Fig. 17B ))Compared to smaller holes ( Fig.17A ). In other words, the smaller intra-fiber distances characterized by the smaller pattern produce higher density and greater capillarity. The smaller pattern provides a larger inter-fiber distance, which results in low density and low capillarity. The result of this combination of pockets in the core is an optimized wicking structure, such as Fig. 17C As shown in Figure 1. Larger holes located in the target area and smaller holes away from the failure point create an effective conduit for fluid flow. This conduit can be used to more efficiently transport liquids against gravity. (See Fig. 17CThis preferred structure can be created in the nonwoven substrate by appropriate selection of the embossing pattern, thereby further spreading the liquid and enhancing the utilization and uptake of the core.

[0142] In other embodiments, and with reference to Fig. 17C and Fig.17D As a result of the SAP swelling, a 3-D pattern or contour can be formed during use (liquid uptake). Fig. 17C and 17D As shown, bags of different sizes provide differences in swelling capacity, which in turn leads to differential swelling. In one aspect, a dam can be created by having a bag with greater swelling (e.g., a larger pillow). This structural result helps reduce leak detection and waist leakage. In most examples, uncontrolled liquid (liquid accumulated on the surface of the product) causes product leakage. The 3-D topography generated when the SAP swells is defined by the embossed pattern size / frequency. An absorbent core that can self-generate a surface topography can prevent cross-surface flow (to prevent leak detection) or hinder leakage at the waist area (the longitudinal ends of the core). Fig.15A The arrangement and structure of the midpockets should be just right to achieve these properties in the absorbent core.

[0143] Other exemplary methods and systems for preparing absorbent composites using SAP

[0144] In a method called profiling, the SAP giving rate is changed to produce a core with a profile. See, for example, U.S. Patent Application No. 12 / 925,765 for a core design with a profile, which is incorporated herein by reference and as a part of the present invention. The core structure with a profile improves diaper performance by providing more absorbent materials in the core area required. It is also possible to achieve profiles with different lengths (e.g., short top core, full-length bottom core) by stacking multilayer absorbent composites. A more efficient solution can be to change the SAP giving rate during the application of SAP and align the high SAP giving area with the crotch area of ​​the diaper when the core is converted in the diaper line. This method may be more efficient when using less nonwoven materials than the superimposed core. It can also be cost-effective.

[0145] In one embodiment, powdered hot melt adhesive is mixed with SAP to provide additional bonding. SAP and adhesive mixture are distributed between 2 nonwoven webs and "activate" hot melt adhesive by passing composite through heating device. Suitable devices include heated rollers, infrared heaters, etc. Adhesive melts and combines SAP and nonwoven fabric together. This can also be combined with patterned embossing / ultrasonic processes to produce bag patterns as described above. Generally speaking, adhesive / SAP is mixed with a ratio of 10 to 100 parts by weight of SAP and 1 part by weight of adhesive (1-10% by weight adhesive). Too much adhesive will limit the absorption performance of SAP, and too little adhesive will sacrifice structural integrity. Preferably, adhesive is applied with a ratio of about 1 to 2 adhesive particles per SAP particle. If the average particle size and density of SAP and adhesive are known, the exact ratio can be calculated.

[0146] The absorbent composite is thus also well suited for manufacture in both offline and online manufacturing processes. In offline processes, the core machine is located separately from any other processes and produces raw rolls, spools or boxes of festooned decorative material, which are then delivered to the diaper converting line. Generally, but not necessarily, the core machine is placed separately from any other processes and produces raw rolls, spools or boxes of festooned decorative material, which are then delivered to the diaper converting line. Figure 6-7 The product-related machine will produce a wide sheet of absorbent composite. The product is then split to produce multiple material rolls for the diaper conversion line, that is, a 1.5m wide machine will produce 15 material rolls of 100mm width. In the offline process, the offline machine generally runs at a much lower speed than the diaper conversion line. In the online process, the core machine is part of the diaper conversion line and the core becomes part of the diaper conversion method. The output speed of the core machine must match the speed of the diaper conversion line and the width of the core will match the width of the core in the product.

[0147] exist Fig.18AIn the offline process shown, a SAP sandwich is formed, which has a substrate A, a second substrate B and a SAP coating placed between the two substrates. In one embodiment, the SAP is fixed by combining two substrates together to accommodate a discrete planar volume of SAP between the two layers. One or a combination of the following methods for SAP stabilization can be used. In the first process, hot embossing or ultrasonic bonding is used to fuse the substrate layer into a defined pattern. In the second process, an adhesive is applied to one or both sides of the inner surface of the substrate. The two substrates are then strategically combined together according to a preferred embossed pattern. The third, a thermal adhesive, such as low-melting adhesive particles, can be mixed with SAP particles. External heating is then applied to the composite to activate or melt the adhesive, thereby bonding the particles to the substrate or to each other. Therefore, a patterned embossing step can be applied to enhance the quality of the stacking while maintaining a more open SAP layer structure for strengthening liquid intake. If a pattern is not required, a smooth calendering roller (without a pattern) can also be used to combine the cover layer with the SAP layer to produce a sandwich structure.

[0148] In the online process, the core forming process is directly coupled with the diaper conversion process. According to the above-mentioned first and second processes, a SAP sandwich structure is formed at 3-4 times the offline process speed. The third method may not be suitable for faster online processes due to the short residence time required for the thermal adhesive mixed with SAP for heating and activation. The offline process is designed to produce wide materials at a lower speed. The material output is then divided into narrower widths to provide multiple diaper lines. On the contrary, the online process is designed to produce narrow (1-width) materials at a higher speed and simultaneously supply the core material only for one diaper machine.

[0149] Therefore, in a preferred embodiment of an offline process according to the third method described above, a small amount (10% or less) of hot melt particles is mixed with SAP. The particle mixture is uniformly deposited on substrate A and then heated by radiant IR to melt the adhesive particles. A second substrate B is then placed on top while the material is still hot. The layers are immediately laminated together using hot embossing by a patterned roller / smooth anvil embossing system. Table 2 below summarizes the process and provides certain parameters of a preferred embodiment.

[0150] Table 2. Exemplary Off-line Processes for Manufacturing Using Hot Melt Adhesives

[0151]

[0152] Coating lines manufactured by Santex, Tobel in Switzerland offer SAP scattering technology, IR heating and web treatment. See e.g. Fig.18B .like Fig.18BAs shown, the scattering unit uses a hopper and a standard rotating pin roller to mix and apply the mixture to the web. According to its suitability for application, the SAP material is selected, but in general, it is preferred to have a high retention capacity and high absorbency under load, for example, a centrifuge retention capacity (CRC) of 20-40g / g, and a pressure absorbency index (PAI) of more than 100g / g. An exemplary SAP is M-151 produced by Nippon Shokubai. A suitable hot melt adhesive is a low-melting EVA polymer Abifor 1605 (0-200 micron particle size), which is currently available from Abifor Energy Technology Company (Abifor Powder Technology) in Switzerland. As described in detail in Figure 18, the readily available scattering unit uses a pin roller when mixing and applying the mixture to the web. The specific bonding pattern of this embodiment is an elongated rhombus with a major axis length of 50mm MD direction orientation and a minor axis length of 22mm. See, for example, Fig. 18C .

[0153] Fig.19 An absorbent composite 910 is shown, which is formed by Figures 18A-18C The method and system described herein produce. Preferably, the composite 910 comprises a bottom substrate A which is a bulky nonwoven, a top layer or substrate B, and superabsorbent particles S located between the two layers and intercalated with hot melt adhesive particles HM (as described above). More preferably, the top substrate B is provided by a cotton material commercially available and understood in the art. Alternatively, the top substrate B may be provided by a second bulky nonwoven layer or a SMS or spunbond ("non-bulky") nonwoven layer.

[0154] As described above, the laminate of absorbent composite 910 can be manufactured online or offline. The laminate can be modified to include other or different SAP loadings (i.e., contoured cores) as described above. In an offline process, the composite can be delivered in the form of a wide sheet that is cut and divided into individual core composite portions.

[0155] Fig. 20A and 20B 810 is a cross-sectional view (laid flat) of a disposable absorbent article 812 comprising an absorbent core laminate 812 or absorbent composite 810. For purposes of describing aspects of the drawings, the complete absorbent composite extended to provide the absorbent core of the disposable absorbent article may be referred to as the absorbent core laminate, while the absorbent composite may be used to describe a component of a portion of the laminate. Additionally, including in the claims, the terms may be used interchangeably. The absorbent core laminate 812 features spaced-apart pockets 814 having SAP (superabsorbent particles (S)) aggregates 816 contained therein. Fig. 20C A detailed cross-sectional top view of one of the bags 814 is provided. Fig. 20C Components of a preferred absorbent composite 810 are also shown.

[0156] Reference now Fig.28 , according to the present invention, a basic disposable absorbent article 862 (laying flat) is shown containing an absorbent core laminate 812 as an absorbent core. The absorbent core laminate 860 is completely covered by a top layer 864, but for convenience, the top layer 864 is shown as transparent. The absorbent core laminate 860 is supported by side edges 868 on a wide back layer 866. Each side edge 868 is provided with a cutout showing a concave shape on each side of the absorbent core laminate 860. As is generally known, the concave cutout will fit or correspond to the leg hole around the thigh of the user.

[0157] refer to Fig. 20C In a preferred structure, the nonwoven material provides the base or bottom layer 818 of the composite (during the manufacture of the absorbent article product). During use of the product, the base layer 818 can be described as being placed away from the body, opposite to the body side that is located directly receiving the ingested absorbent composite 810. In addition, in this embodiment, the nonwoven layer 818 has an adhesive layer 822 applied thereto. The adhesive layer 822 is preferably delivered in the form of continuous beads, on the base nonwoven 818 and in a preferred open pattern, as shown below.

[0158] The absorbent composite also includes a SAP layer 806 located above the adhesive layer 822 and between the bottom nonwoven 818 and the top nonwoven layer 826. In this embodiment, the SAP layer 824 consists only of SAP particles S without any form of binder material or matrix. It can also be described as lint-free or pulp-free. The top nonwoven layer 826 is preferably provided by a fluffy nonwoven material having fibers of some SAP extending and laterally entangled on or near the top surface of the SAP layer 806. The top nonwoven 826 is preferably bonded to the bottom nonwoven 818 by embossing and more preferably by point connection. The bonding points 828 define the periphery of the bag 814 and also press the elastic fluffy nonwoven 826 on the periphery of the bag to show all bubbles or hemispherical cross-sections (such as Fig. 20C shown). Fig.29 The simplified illustration of provides an alternative view of the absorbent composite 810 (and more specifically the composite components) without showing the point bonding and compression around the periphery of the pocket 814.

[0159] In this preferred structure, the fluffy nonwoven layer 826 contacts and covers the SAP layer 824, thereby limiting the movement of the SAP particles S. During manufacturing and product handling, the fluffy nonwoven layer 826 is also preferably placed as the top layer to limit the movement or migration of the SAP particles before use. During use of the absorbent article, the fluffy nonwoven 826 is also preferably placed on the body side to receive and distribute the intake to the SAP layer.

[0160] In this preferred structure, the SAP is organized into discrete, spaced-apart SAP aggregates or clusters 816, as described above, which are each held in a bag or container 814. The two nonwoven layers 818, 826 are bonded at the bonding sites, or, more specifically, at the array of discrete, spaced-apart bonding sites 828. Thus, the bulky nonwoven 826 is multiply and intermittently secured to the SAP aggregates 816 and helps to hold the SAP aggregates 816 in place. The unique functions and properties imparted to the absorbent composite and absorbent core laminates through the use of bulky nonwovens are described below.

[0161] Fig.21 22 provides a cross-sectional view of an absorbent composite 810 or absorbent laminate 812 and its various components or layers in relation to each other according to a preferred embodiment. FIG. 22 provides a basic process or step for making a composite by showing the order in which the components of the composite are incorporated together. Reference should also be made to the previous description of making absorbent composites or absorbent articles using the composites, including Figure 1-5 Many of the process steps and process components described herein may be applied or adapted to prepare Figure 19-29 The absorption complex.

[0162] In the initial step of the preferred method, the nonwoven 818 web is transported in a conventional manner and then passed by an adhesive applicator. The spray adhesive applicator preferably delivers continuous beads to the nonwoven 818 in an open adhesive pattern (see Fig.22A ). In this way, a ring of adhesive 822a is provided on the surface of the nonwoven material 818, which is characterized by or defines an open area (rather than a uniform layer or film) that does not contain adhesive. The ring 822a in the exemplary embodiment is smaller than the bag 814 described previously (i.e., smaller in width or diameter), and is generally 1 mm to 25 mm in diameter.

[0163] Fig. 22B The delivery of SAP aggregates 816 to a substrate consisting of a base nonwoven fabric layer 818 having an adhesive layer 822 or an adhesive layer applied thereto in an open pattern is shown by methods described herein or known in the art. Specifically, the SAP is delivered by air flow and by using a conventional vacuum system or suction mechanism, such as those previously described herein or known in the art. The suction applied above or below the nonwoven fabric 818 web pulls the SAP toward the nonwoven fabric 818 and organizes the SAP into a desired pre-arrangement of aggregates or clusters 816 of SAP (such as Fig. 22B). The vacuum system may employ a screen or mesh interface to better engage the bottom of the nonwoven and define the target geometry of the SAP aggregate. Thus, the interface displays a suction pattern corresponding to the desired bag shape of the SAP aggregate 816. The vacuum system preferably pulls the SAP directly out of the airflow on the web and forms discrete clusters or aggregates on the web under the above-mentioned suction mechanism. Certain areas, including those along the sides and ends, are referred to as SAP-free (also additive-free) areas and are purposely kept free of SAP.

[0164] SAP generally directly falls into the required arrangement, contrary to being limited to being distributed online and then forming a tighter concentration (as shown in alternative embodiments) online after moving around the net. SAP generally need not move on the adhesive on the net to form a plurality of SAP aggregates 816 of target. Therefore, the net of gained is composed of the arrangement or layer 806 of the nonwoven base layer 818 and the discrete, separated SAP aggregates 816 with open adhesive pattern 822 thereon. The cluster of SAP is generally placed and contacts adhesive, but the bottom layer that the open pattern of adhesive occupies is significantly smaller than that of SAP aggregate contact. However, it should be noted that the SAP particles of the contact adhesive can be generally fixed. Another kind of SAP particles placed adjacent to this fixing SAP particle and contacting can then be limited (moved) or at least partially fixed by this SAP particle (and / or other adjacent SAP particles). This friction mechanism hinders the horizontal movement of SAP particles at least.

[0165] As the web of nonwoven-SAP moves forward and is removed from the vacuum system, the adhesive pattern 822 serves to maintain the desired arrangement and position of the SAP aggregates 816. In a subsequent step, a web of a second nonwoven 826 is transported forward and then applied to the nonwoven-SAP laminate. See 22C. As described above, the preferred top nonwoven 826 layer is a fluffy nonwoven. For other processing and movement of the SAP aggregates 816 during the preparation of absorbent articles such as diapers or training pants, the additional nonwoven 826 provides additional coverage and serves to keep the SAP aggregates 816 in the desired pattern. In addition to providing preferred functions in the finished product and during use, the fluffy nonwoven 816 entangles the SAP particles S of the top layer, such as Fig.29 As shown, the SAP aggregate 816 is further fixed (during production and subsequent post-production product handling). The entanglement of the SAP with the fluffy nonwoven restricts the lateral and vertical movement of the SAP near the top of the SAP aggregate 816, and hinders the direct movement of the SAP below it. As described herein, the SAP and the fluffy nonwoven are defined and selected taking into account the desired degree of entanglement and penetration.

[0166] Next, the two nonwoven webs and the SAP aggregate therebetween pass over a calender roll that intermeshes and compresses the webs. As mentioned above, the calender roll has a surface engraving having a pattern corresponding to the pattern of the bags on the webs. Fig.23 A generally bonded absorbent composite laminate 812 using discontinuous point bonding is shown. The dots reflect the impressions of the embossed bulky nonwoven 826. The dots are also the bonding points 828 of the bag 814 (see also Figures 20A-20C ). Fastening the two nonwovens together around the SAP aggregate 816 provides another mechanism for maintaining the alignment of the SAP aggregate 816 and the resulting absorbent laminate 812. As described herein, the arrangement of the bonding points provides a geometric grid 830 that positions and defines the pockets 814 of the SAP aggregate 816.

[0167] Therefore, in this exemplary embodiment, during the manufacture and post-manufacturing treatment of absorbent products, the preferred SAP laminate structure is extracted from several structural features to prevent SAP particles from moving from the desired arrangement of SAP aggregates. First, an adhesive is provided on the base nonwoven layer and SAP aggregates are placed on the adhesive. However, an optional adhesive layer is delivered in an open pattern of a closed loop, which only contacts certain bottom SAP particles but prevents the movement of SAP particles on these contacted SAP particles. Applying a top nonwoven layer on the SAP aggregate increases the minimum applied adhesive to further limit the movement of SAP. Preferably, the SAP layer delivered to the base nonwoven is slurry-free and does not contain a matrix or a binder, which optimizes the absorption and fluid control properties of the composite. In addition to the bottom adhesive, it is also free of adhesive. Therefore, many parts in the SAP layer (especially the middle part of the SAP layer) are composed of SAP, but in alternative embodiments, other materials may be included to impart beneficial properties. As described above, a thinner, looser, softer SAP structure is produced mainly by only SAP. At the same time, the improved absorbent properties and fluid handling characteristics are provided by the majority consisting of only SAP, which is substantially held in place (preventing SAP particles from migrating).

[0168] As another enhancement, the preferred SAP laminate structure employs discrete or intermittent bonding points in conjunction with the laminate structure shown in FIG. 22. Fig.23. An embossed pattern providing discontinuous or spaced apart bond points provides a synergistic effect by employing the SAP laminate structure of Figures 20-22 and / or using a bulky nonwoven layer as the top or body side layer of the absorbent laminate (or vice versa). The gaps provided between the bond points allow fluid to pass between SAP aggregates, including fluid flow from only the SAP middle portion of the SAP laminate. The provision of a bulky nonwoven and / or adhesive reduces the need for complete or continuous bond lines. Similarly, the location of the bulky nonwoven and / or point bonds reduces the amount of adhesive required for SAP stabilization.

[0169] Furthermore, the reduced contraction of the bulky nonwoven layer by using embossing points rather than longer bond points or solid bond lines allows the elastic bulky nonwoven to expand and preferentially receive and distribute fluid intake. Fig. 20C The bond points shown compress the bulky nonwoven, but the elastic bulky nonwoven "bounces" from the bond points. See also Fig.30 This results in a more open substructure with good fluid handling functionality. In addition, the function of the SAP-only composition is to receive and absorb fluid intake, and if necessary, pass the fluid intake through the gaps between the bonds to the adjacent SAP pocket. In one aspect, there is a channel for fluid from a relatively open fluffy nonwoven layer on a certain surface, through the fluffy nonwoven layer and into the SAP-only body, and from the middle layer of the SAP-only body from the side to the gaps between the bond points, and then into another preferably substantially SAP-only aggregate.

[0170] Fig.24 The plan view shows the bonded absorbent core stack 812 secured to each other by discrete bonding points 828. Fig.24 Shown is a preferred pattern of a SAP bag 814 according to this exemplary embodiment. The stack 812 is extended to have a certain transverse width dimension and a longitudinal length dimension. The shape of the stack 812 at this stage is generally rectangular. As mentioned above, the embossing process preferably uses intermittent bonding patterns to enhance fluid flow between bags. The selected bag pattern uses diamond embossing to produce a diamond bag 814. An advantage of using a diamond bag and a corresponding grid is that it is easier to design and match the engraved pattern on the embossing roller and the interface of the vacuum system using directly interconnected lines.

[0171] Preferably, the diamonds are arranged so that the series of bond points or embossed lines do not coincide with the side edges of the core. The straight lines (SL) that align the bond points that may exist on the surface of the stack 812 are preferably oriented at an angle less than 90 degrees relative to the side edges, and more preferably between about 60 degrees and 30 degrees. In this way, the length of the interconnected bond lines (SL) that can provide potential fluid pathways (i.e., on the surface and in the pocket 814 and along the line) does not exceed the perpendicular line to the side edge 834 (which can represent another pattern). This solves possible fluid leakage to the side edge 834 and promotes the fluid path to be divided into the unsaturated pocket downstream.

[0172] The absorbent core laminate 812 is also characterized by a SAP-free line 838 near the side edge 834 and near the end edge 836. The step of delivering SAP on the bottom nonwoven layer and organizing the SAP aggregate is designed so that these areas do not have SAP to minimize the use of SAP. Afterwards, the area is sealed and in the case of the side edge, a curved portion can be cut from the absorbent core laminate 812 to adapt to the leg incision and / or produce an hourglass-shaped core. There is no SAP in these areas to make a softer and foldable material layer. This also avoids the need to cut (or seal) in a harder, more rigid SAP material that may be needed during the manufacturing process, thereby promoting cleaner and more accurate cutting (and sealing). Perhaps more importantly, this avoids the need to wear a cutting knife and maintenance and downtime for the manufacturing device.

[0173] Fig.25 840 is shown in plan view with an alternative absorbent core laminate 840 using an alternative pocket pattern and a bonding pattern. The bonding pattern uses continuous bonding lines 842 that create a fixed grid, as opposed to intermittent bonding. As in the previously described embodiment, diamond-shaped pockets 844 are used. In addition, the potential fluid pathways created by connecting the bonding lines involve an angle away from the side edges (i.e., 45 degrees), thereby slightly reducing the risk of direct flow to the side edges.

[0174] As used herein, a diamond-shaped bag means a bag with four sides and preferably aligning 2 longitudinal angles with each other and aligning the other 2 transverse angles. The bag is preferably not oriented to a rectangle that conforms to the transverse and longitudinal center lines of the laminate, wherein the binding lines constitute a "direct" straight path leading to the side edge. As used herein, the term "grid" means that a geometric shape is established by crossing lines along the binding sites or embossing lines. In addition, as used herein for the arrangement or geometry of the bag, a "direct" straight path represents one or more binding lines connected to form a continuous and common (non-"interrupted") path from near the longitudinal center line to the side edge, wherein the path is generally perpendicular to the side edge. This direct straight path constitutes the shortest fluid path leading to the side edge. For the sake of clarity, this deviation from the vertical straight path exceeding 30 degrees should be referred to as an indirect straight path rather than a direct straight path. A straight path without such a deviation is considered to be a "direct straight" line path.

[0175] It should be noted that other "grids" and other bag shapes and bag arrangements can be used. Some of the bag shapes used do not show any direct or any straight line path to the side edge. This includes some of the arrangements described above, including arrangements of circular or oval bags.

[0176] Contoured core compound

[0177] In this preferred embodiment, the method for manufacturing the absorbent core includes the step of delivering the core structure with profile. The method is other versions of the aforementioned method, and in a preferred method, includes all steps of the aforementioned method. For example, although the previous method can adopt a single SAP applicator, the method of the present invention can adopt a second SAP applicator to increase the SAP delivery of the first SAP applicator. The second SAP applicator can be located upstream (front) or downstream of the first applicator. In the case where the nozzle of the first applicator can be cut to cover the width of the target core, the second applicator can be cut to cover the narrowing portion of the core. In addition, the second applicator can be programmed to deliver a continuous specific time period, which is a part of the delivery time period of the first applicator. For example, the first applicator can be programmed to continuously deliver (except for the narrow and SAP-free channel at the side edge) to almost the entire width of the SAP core. The second applicator can be cut and programmed to deliver SAP to a narrower central area and / or a continuous intermittent time period, which corresponds to the central area of ​​the core. In an exemplary embodiment, a second SAP applicator is located downstream of the first SAP applicator so as to deliver a second dose or loading of SAP onto the SAP first deposited on the nonwoven web. Thus, the SAP aggregates originating from the second applicator (as well as the first applicator) are arranged to have a higher SAP loading than other SAP aggregates originating only from the first applicator.

[0178] As described above, the preferred process uses a suction mechanism and screen to organize the SAP bags on the net. After delivery, the SAP load is quickly pulled into SAP aggregate formation. SAP aggregates derived from 2 SAP applicators provide bags with thicker and larger SAP layers than bags that are not so sourced.

[0179] In a preferred arrangement, the dual SAP loading pockets are located in the center area where the most ingesta occurs. In other embodiments, the composition of the 2 SAP loadings may vary to achieve a desired mixture or desired absorption or fluid handling properties. In other embodiments, other SAP applicators may be employed and strategically placed to produce the desired SAP pocket pattern and functionality.

[0180] Uses of Fluffy Nonwoven Fabrics

[0181] "Bulky" in this article means and provides an open fiber network or a web of hydrophobic but non-absorbent fibers. In addition, as described herein, the bulky nonwoven fabric has a thickness of 100 μm to 10000 μm (preferably 1000 μm to 5000 μm), 15 g / m 2 Up to 200g / m 2 (Preferably 20g / m 2 Up to 80g / m 2 ) basis weight, and a fiber web material with a density of 0.01g / cc to 0.3g / cc (preferably 0.01-0.08g / cc). In addition, the fluffy nonwoven fabric will have an effective pore diameter of 300μm to 2000μm. In general, the particles of the selected SAP will have an average particle size of about 300μm, which ensures some penetration or entanglement between the SAP and the selected fluffy nonwoven fabric. The following Tables 3 and 4 can be used to further define the fluffy nonwoven fabric and show the relationship between key properties. (The shaded area in the table refers to the fluffy nonwoven material of the present invention). The effective pore diameter is estimated by the web density, fiber diameter and fiber density value according to the method of Dunstan and White, J.ColloidInterface Sci, 111 (1986), 60, where the effective pore diameter = 4*(1-solid volume fraction) / (solid volume fraction*solid density*solid specific surface area).

[0182] Suitable fibers include polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polylactic acid (PLA), polyolefins, copolymers thereof or any combination thereof, including biocomponent fibers. Fibers are typically treated with a surface active agent, a surfactant, to modify the surface tension of the fibers so that they are hydrophilic.

[0183] Table 3.

[0184] Web Thickness (in microns) vs. Basis Weight and Density

[0185]

[0186] Table 4.

[0187] Pore ​​diameter (in microns) versus density for a given fiber size and fiber density

[0188]

[0189]

[0190] Referring to Figures 16 and 17, as described above, there are fluid handling benefits that accrue from employing a bulky nonwoven as the fabric in an absorbent composite. In addition, orientation of the absorbent composite with a bulky nonwoven on the body side is particularly preferred because it enhances the absorbent composite's ability to acquire and distribute fluid intake. The bulky nonwoven has high void volume and permeability and allows the composite to quickly capture and effectively distribute fluid away from inactive spots.

[0191] In addition, the bulky nonwoven fabric having the embossed pattern also has the following characteristics:

[0192] The "pillow" structure as the body side layer is provided by a bulky nonwoven fabric (see e.g. Fig. 20C , Fig.29 and Fig.30 ) creates a compressible and elastic structure that enhances the soft feel.

[0193] In the pocket region, there is a pore size gradient (see e.g. Fig. 20C and Fig.30 ) which causes the liquid to move from the ridges (more open areas with greater inter-fiber distance I) up to the bonded areas (tighter areas with smaller inter-fiber spacing). This is shown in Fig.30 , which shows a fluffy nonwoven fabric 826 showing a smaller inter-fiber distance I toward a bonding point 828. Since capillary action is negatively correlated with density, the capillary action in a tighter area is higher than in a more open area, so the liquid in the fabric tends to flow to the tighter area. This is particularly important for dry feeling, because this allows the remaining liquid on any ridge to flow to the bonding area and further flow into the SAP structure below, where the liquid is tightly held. Therefore, a relatively liquid-free top surface is created, which contributes to dry feeling. This pore gradient also prevents fluid from flowing back to the surface.

[0194] The discontinuous bond pattern also contributes to a softer feel by creating a softer composite.

[0195] Spray adhesive

[0196] Adhesives may be used to provide additional bonding of the composite and may be used to assist in securing the SAP to the nonwoven. This is required during the manufacture of the composite, further processing of disposable absorbent articles containing the composite, and storage and final use of the composite in absorbent articles. Ideally, the adhesive is applied to at least one of the nonwoven webs of the composite, or the adhesive may be applied to both the upper nonwoven web and the lower nonwoven web.

[0197] Suitable adhesive comprises hot melt adhesive, and it is tried by slot coating or spray applicator (as provided by Nordson company).In a preferred embodiment, adhesive is applied by spraying method, wherein the continuous beads of hot melt adhesive are guided into pattern, such as spiral pattern or more random pattern by air stream.Figure 22 shows one such pattern.The diameter range of spiral is 1mm to 25mm.The advantage of this spraying pattern is that the adhesive on nonwoven web covers unevenly, and there is open area that does not contain adhesive basically.These open areas provide unrestricted passage to fluid through nonwoven web and enter superabsorbent layer, and wherein uniform coating can delay or reduce the fluid flow through net.

[0198] In other and multiple embodiments of adhesives, preferred adhesives are hydrophilic. In addition, the concentration of adhesive in the coating is 0.5 to 100 grams per square meter. Optimally, the concentration is 1 to 25 GSM. In a preferred embodiment, the concentration is 2 to 10 GSM.

[0199] To illustrate possible variations of the preferred embodiment, Fig.26 A cross-sectional view of an absorbent core stack 850 of an alternative embodiment is provided. As described above, the absorbent core stack 850 adopts a base nonwoven layer 818 having an adhesive pattern 822 pre-applied thereon. The stack 850 also provides a first layer 816 of SAP aggregates separated by intervals, which substantially occupy the transverse and longitudinal regions of the stack 850. The adhesive pattern 822 and the SAP aggregates can be applied as described above, and the SAP is delivered by a SAP applicator and organized into a desired bag pattern with the assistance of a conventional vacuum system, etc., as described above. In this variation, a second SAP applicator can be located downstream of the first SAP applicator to deposit SAP on a selected area of ​​a net having a first layer of SAP aggregates 816 thereon. The area where the absorbent material that selects to receive additional SAP components or possible properties different from the SAP delivered for the first time is generally the central area corresponding to the crotch area when using a disposable absorbent article. The SAP applicator can be configured with a nozzle or spray area narrower than the first SAP applicator during the overlap of the machine direction and the transverse direction of the stack 850. Thus, the area where the SAP is delivered will be narrower than the SAP layer 816. If the machine direction and the longitudinal direction coincide, the second SAP applicator can be programmed to deliver SAP only during the time period when the movement of the center zone is aligned under the second SAP applicator.

[0200] refer to Fig. 20A and 20B, the pockets 814 in the central zone 854 contain a concentration or SAP aggregate that exceeds the SAP concentration in the pockets 814 near the longitudinal end zones 856 near the absorbent core laminate 812. In between these areas and the central zone, there are pockets 857 containing SAP at a more or less intermediate concentration. The SAP concentration in these pockets 857 can be determined by the extent of the second SAP applicator and possible averaging of excess SAP between adjacent pockets. As described herein, these pockets 857 can be used as a gradient transition between high and low capacity and absorption and swelling properties of SAP, and can create beneficial fluid flow (in the absorbent core).

[0201] Reference again Fig.26 , this embodiment is also equipped with a second adhesive pattern 862 to assist in securing the SAP in the bag. The adhesive pattern 862 can be the same as the open pattern 822 preferably applied on the bottom nonwoven fabric, and will be pre-applied to the top nonwoven fabric 826 before the top nonwoven fabric 826 is introduced into the resulting laminate 850. In the resulting structure, this second adhesive pattern 862 helps to secure particles of the SAP aggregate that are in contact or near contact with the top nonwoven fabric 826. If a fluffy nonwoven fabric is used as the top nonwoven fabric 826, the adhesive helps to secure the SAP in the top layer area of ​​the SAP aggregate to the fluffy nonwoven fibers, including promoting SAP entanglement. When two adhesive patterns are used in the laminate design (such as Fig.26 The total amount of adhesive applied in each pattern (e.g., thickness of the beads, size of the loops) may be reduced. In addition, the number or frequency of bonding points may also be reduced. The various mechanisms used to secure the SAP in the bag 814 may have different effects on the SAP and come from different angles, but work together to achieve a common purpose.

[0202] Fig. 27 Subsequent stages in an exemplary process for making an absorbent core laminate and / or a disposable absorbent article are shown. A web 870 of a separable absorbent core laminate 872 is shown conveyed in a cross-direction coincident with the machine direction. The laminate 872 is shown prepared in an hourglass shape. The delivery of SAP to the base nonwoven is provided so that a SAP-free region 874 is proximate to or along a final side edge 876 of the individual absorbent core laminate. In addition, as shown Fig. 27 As shown, in making the cutouts to accommodate leg holes and / or simply to create a preferred hourglass shape that helps to fit or accommodate the user more easily in the crotch area, the wider area 878 near the center of the side edge 876 is also free of SAP. In this way, the use of SAP can be reduced and material costs can be reduced.

[0203] In any event, a narrow area sheath 852 of SAP aggregates is deposited on the first layer 816 and in the selected central region. A vacuum system can be used again to guide the SAP deposition to the target area. In this way, a higher concentration of SAP aggregates can be generated.

[0204] Generally, the absorbent core laminate 812 is extended by a pair of longitudinally spaced apart end regions 856 and a central region 854 therebetween. The absorbent core laminate is located between the top and back layers, which are referred to as the "core envelope" 880. See also Section Fig. 20A and 20B . Fig. 20A can be described as a transverse cross-section of the core envelope 880 (i.e., through the transverse centerline XX), while Fig. 20B It is the longitudinal cross-sectional view (that is, passing longitudinal neutral line YY) of core envelope 880. Absorbent core stack 812 is also described as having the side edge extending between end regions 856. The arrangement of the bag 814 of SAP aggregate 816 is set between the side edge 812. As shown in the drawings, the pattern or grid on the absorbent core stack 812 is defined by arrangement. Around the central area 854, a pair of incisions 882 in the side edge 856 provide concavity to the generally rectangular stack 812, which reduces the group of bag 814 in the central area 854. This concavity makes absorbent core stack 812 form a generally hourglass shape. Because central area 854 generally corresponds to the crotch area of ​​disposable absorbent article 862, the concavity of absorbent core 812 and generally do not have the core material of harder (than top layer and back layer material) promote the use period absorbent article 862 in the crotch area deformation, and help to adapt to the profile of the user.

[0205] Therefore, the present invention is well suited to carry out the above-mentioned purpose and achieve the above-mentioned endpoint and advantages, as well as other inherent properties. Although the preferred embodiment (diaper form) has been described, the structure, arrangement, and details of the steps of the method can be made into various changes. For example, various top layers, back layers, absorbent cores, capacity walls and other absorbent composite structures can be used in other parts of the product or in other products other than diapers. Those skilled in the art will be easy to propose such changes and are included in the spirit of the present invention and the scope of the appended claims.

[0206] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and modifications may be made to this document without departing from the present invention as defined by the appended claims. In addition, the scope of this application is not intended to be limited to the specific embodiments of the process, machine, manufacture, and composition of the form, means, method, and steps described in this specification. It can be easily understood by this disclosure that the process, machine, manufacture, and composition of the form, means, method, or step that are implemented or achieved substantially the same function or substantially the same result as the corresponding embodiments described herein can be used. Therefore, the appended claims are intended to include the process, machine, manufacture, and composition of the form, means, method, or step within their scope.

Claims

1. An absorbent core composite for a disposable absorbent article, the composite comprising: First Fabric; A second body-side fabric; and a plurality of superabsorbent particle (SAP) aggregates positioned between the first and second fabrics; in, an arrangement of spaced-apart bonding sites around each of the plurality of SAP aggregates securing the second fabric to the first fabric and forming a pocket in which the SAP aggregates are secured between the first fabric and the second fabric; The spaced-apart binding sites around the SAP aggregate provide gaps between the binding sites that allow one of the pockets to communicate with an adjacent pocket; and The second body-side fabric is a bulky nonwoven fabric comprising fibers having at least some particles entangled in the SAP aggregates.

2. The absorbent core composite according to claim 1, characterized in that Each of the SAP aggregates is free of an absorbent matrix.

3. The absorbent core composite according to claim 1, characterized in that The SAP aggregates consist of superabsorbent particles.

4. The absorbent core composite according to claim 1, characterized in that The second fabric comprises fibers penetrating the SAP aggregates at the top superabsorbent particle layer, the SAP aggregates being free of an absorbent matrix.

5. The absorbent core composite according to claim 1, characterized in that The compound further comprises: A pattern of adhesive is applied to the first fabric and bonded to superabsorbent particles contacting the SAP aggregates, the superabsorbent particles being located in a bottom layer of particles of the SAP aggregates adjacent the first fabric to at least partially immobilize the superabsorbent particles of the SAP aggregates.

6. The absorbent core composite according to claim 5, characterized in that The adhesive pattern applied to the first fabric comprises a plurality of interconnected loops defining open areas that are free of adhesive.

7. The absorbent core composite according to claim 1, characterized in that The width or diameter of the open areas free of adhesive is generally smaller than the width or diameter of the pockets located in the adhesive pattern.

8. The absorbent core composite of claim 1, wherein: The second fluffy nonwoven fabric has a thickness of 1000 μm to 5000 μm, a density of 0.02 g / cc to 0.07 g / cc, and a basis weight of 20 g / m 2 Up to 80g / m 2 , density is 0.01 g / cc to 0.08 g / cc, and the effective pore diameter exceeds 300 μm.

9. The absorbent composite of claim 8, wherein: The bulky nonwoven fabric comprises fibers selected from the group consisting of polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polylactic acid (PLA); polyolefins, copolymers thereof, and combinations thereof; and the fibers are hydrophilic treated fibers.

10. The absorbent composite of claim 10, wherein: The first fabric is a nonwoven material, and the first and second fabrics at least partially define an elongated laminate having a transverse width, a longitudinal width, and a central region located about an intersection of a transverse centerline and a longitudinal centerline of the elongated laminate.

Images