CZ20001253A3 - Layered absorption structure with zonal distribution of basic weight - Google Patents

Abstract

The object of the present invention is specifically designed the absorbent article (20) includes an absorbent core (30) with a plurality of absorbent layers interacting with each other so as to ensure preferential localization of the absorbed liquid into a determined, highly saturable, absorbent layer. Localizing the liquid to said acquisition layer increases the potential of this liquid transfer layer via capillary rise as a result of higher levels of saturation and increased liquid available. According to another aspect of the present invention, it exhibits at least one primary layer uneven, selectively divided zonal basis weight. Specific configuration at least one primary layer portion may be formed with a receiving zone having a basis weight which is smaller than the remaining basis weight to receive an unspecified part of this primary layer lot.

Description

The present invention generally relates to a layered absorbent structure. In particular, the present invention relates to a layered composite absorbent structure provided with specific layers which are designed and arranged for selective interaction with each other so that the composite layered absorbent structure provides the desired functional and performance parameters.

BACKGROUND OF THE INVENTION

Functional requirements imposed on disposable absorbent articles, such as diapers, include the complete elimination of any leakage, a feeling of dryness on the part of the user, and adaptability and comfortable fit throughout their functional life. Therefore, such absorbent articles typically comprise an absorbent core that serves to provide controlled control of the acting fluid and other characteristic absorbent properties required to meet the above-mentioned functional requirements. The absorbent core of such articles generally consists of wood pulp in fibrous form, and in the absorbent core there is in most cases a distributed superabsorbent material which serves to increase the absorbency of the acting liquid. The absorbent core typically has an hourglass shape, a T-shape, or the like with a reduced width of the absorbent structure in the central crotch region to provide adequate fit, and user-friendliness.

In many cases, absorbent articles leak before. the absorption capacity of the absorbent core as a whole is fully utilized. One problem that causes leakage is the inability of the absorbent core to rapidly and completely absorb the acting liquid when a large amount of the liquid is introduced into the absorbent article during the impact of the liquid. Another problem that may cause undesirable leakage is the inability of the absorbent core to distribute or transfer sufficient fluid from the absorbent zone of the absorbent article to more and more distal end regions of the absorbent core that have not been utilized. This leads to saturation of only the central acquisition zone of the absorbent core and to the formation of excessive thickness, high bulkiness, heavy and wetted warping of the absorbent structure, resulting in poor efficiency, improper fit, and user discomfort. Said drawbacks of the absorbent cores are particularly critical for thin crotch absorbent articles having a width of less than about 4 inches in the crotch region, so that they provide less absorbent material in the receiving zone and are thus unable to provide the desired functional efficacy.

The absorbent cores of existing absorbent articles are unable to meet the above functional requirements. Proposals to ensure the necessary efficiency of the absorbent core, that is, rapid absorption and distribution acting

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The liquid, with the upstream narrowing of the crotch region, increasing the efficiency of the absorbent article, cannot be overcome with the existing capabilities of the absorbent structures. Accordingly, there remains a need to provide absorbent structures that are capable of providing improved fluid impact processing, and improved fluid distribution and displacement between the fluid impacts, to maintain the enhanced fluid processing and provide an adequate absorbent lifetime. product.

SUMMARY OF THE INVENTION

According to the present invention, there is provided an absorbent system that includes a plurality of absorbent sheet portions. Advantageously, the two or more of said layered layers may interact with each other in a manner that preferably provides for a convenient location of the specified liquid in the selected layered portion. Said localization of the liquid in the layered portion may increase the liquid transfer potential of the layered portion by capillary action due to the higher level of saturation and the increased amount of liquid available. The absorbency of the absorbent system can be assured at the conventional level or improved over existing absorbent systems by keeping the second layer of the absorbent system at low saturation levels during the maximum possible impact of the liquid while ensuring optimal absorbency by adequately controlling the properties of the composite absorbent structure. The low saturation in this layer portion provides sufficient void volume for the impingement fluid to be delivered, as well as high permeability, thereby increasing the suction rate of the absorbent system as a whole. Advantageously, the respective properties of this layer portion may be in equilibrium with a correspondingly high level of capillary stress so as to ensure sufficient control of the liquid transfer and thus substantially eliminate undesired leakage. In addition, the low-saturation controlled layer layer can be used as a buffer layer material, where it can provide an additional suction function in addition to serving as a fluid impact compensating material.

According to specific aspects of the present invention, the user-facing layer of the absorbent structure need not extend over the entire surface area of the absorbent system, and can be configured to provide a suction layer portion that serves as an additional layer for the highly saturable absorbent layer portion. In the described arrangement, the suction layer portion can be located in substantially direct contact with the applied fluid, thereby allowing more immediate access of the impacting fluid to the absorbent structure and providing an improved suction function of the fluid.

According to further aspects of the present invention, the at least one primary layer portion may have a non-uniform, selectively distributed zonal basis weight distribution. Specific embodiments of the at least one primary layer portion may be formed such that in said at least one primary layer portion there is a receiving zone having a basis weight that is 0 · 0 · 0 · 0 · 0 · 0 ·

less than the basis weight remaining, for receiving an unspecified portion of the primary for receiving liquid of the layered portion.

According to other aspects of the present invention, the layers of the absorbent system may interact with each other to provide a desired liquid wicking potential, such as a liquid wicking value of at least about 16%. In addition, the absorbent system of the present invention can provide a desired flow conductivity value, such as a flow conductivity value of at least about 7.10 ^-6 cm ^-3 . According to other aspects of the present invention, the proposed absorbent system may provide a combined conductivity / absorbency value that is at least about 14. 10 ^-6 cm ^-3 . In other aspects, the present invention may provide an absorbent system that is capable of providing a desired flow conductivity value and further comprises at least one layer portion having a desired liquid wicking value. According to still other aspects of the present invention, the absorbent system may comprise a superabsorbent polymer material (SAP) that exhibits a controlled, specific uptake rate. For example, a desired superabsorbent material having a controlled rate of uptake may exhibit a specific rate of uptake, referred to as a Tau value, or a time characteristic, such as a Tau value of at least about 0.67 minutes. According to other aspects of the present invention, the absorbent system may comprise a combination of superabsorbent materials that exhibit a specific ratio of Tau values.

Based on various of the above aspects, the present invention can provide an absorbent article having a higher efficiency absorbent structure having a low β thickness.

And a low volume which exhibits high absorbency and which is resistant to undesirable leakage. Individual embodiments of the absorbent article of the present invention are able to better utilize the potential absorbent capacity of the absorbent structure and at the same time are able to more efficiently distribute and transfer absorbed liquid from the initial acquisition zone to more distal sections of the absorbent structure closer to its distal end regions. In addition, the absorbent structure of the present invention is capable of providing the capability of sucking and absorbing liquid at high speed and maintaining the desired suction rate even after the structure has been wetted and has reached a substantial portion of its potential, total absorbent capacity.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention and its further advantages will be described and explained in more detail in the following detailed description by way of specific examples of embodiments of the invention in conjunction with the accompanying drawing, in which it represents:

Giant. 1 shows exemplary embodiment absorption product in plan view, at which is incorporated invention; absorption system according to submitted Giant. IA shows exemplary embodiment absorption of the product from Giant. 1 in a lateral cross-sectional view incision;

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Giant.

1B shows an exemplary embodiment of the absorbent article of FIG. 1 in longitudinal view and in cross-section;

shows an exemplary embodiment of an absorbent core structure according to the present invention in plan view showing a first topsheet that extends over a central region of the total surface area of the absorbent core and a second bottomsheet that extends substantially over the entire overall surface area a range of the absorbent core, the opposing end edges of the first layer portion in the longitudinal direction being spaced from the corresponding opposing end edges of the second layer portion in the longitudinal direction;

2A illustrates an exemplary embodiment of the absorbent core structure of FIG. 2 in longitudinal view and in cross-section;

shows an exemplary embodiment of another absorbent core structure according to the present invention in plan view showing a first topsheet primary layer that extends over a central region of the total surface area of the absorbent core and a second bottomsheet primary layer that extends substantially throughout the total area of the absorbent core, wherein the second layer portion exhibits an uneven, zonal distribution of the core of the absorbent core.

Giant.

Giant.

Giant.

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a mass with a relatively higher basis weight at its opposite end portions in the longitudinal direction, providing an inverse zonal distribution of the second, lower layer portion in the longitudinal direction;

3A illustrates an exemplary embodiment of the absorbent core structure of FIG. 2 is a longitudinal and cross-sectional view, wherein the selected central portion of the second layer portion has a basis weight that is less than the basis weight of the adjacent, opposite end portions of the layer portion in the longitudinal direction, providing an inverted zonal basis weight of the second layer in the receiving zone ;

shows an exemplary embodiment of a further absorbent core structure according to the present invention in plan view showing an upper primary layer portion that extends over the entire front portion of the lower primary layer portion but overlaps only a portion of the rear portion of the lower primary layer portion;

4A shows an exemplary embodiment of the absorbent core structure of FIG. 4 in longitudinal view and in cross-section;

shows an exemplary embodiment of a further absorbent core structure according to the present invention in plan view having an upper primary layer portion that overlaps the entire lower primary layer portion;

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Giant.

Giant.

Giant.

5A illustrates an exemplary embodiment of the absorbent core structure of FIG. 5 in longitudinal view and in cross-section;

shows an exemplary embodiment of a further absorbent core structure according to the present invention in plan view showing an upper primary layer portion which has, compared to the lower primary layer portion, both a smaller, narrower dimension in the transverse direction and a smaller, shorter dimension in the longitudinal direction;

shows an exemplary embodiment of an absorbent core structure according to the present invention in longitudinal and cross-sectional view, comprising a lower primary layer portion formed of a laminate material in which the superabsorbent material particles are sandwiched and held between layers of liquid-permeable material;

illustrates an exemplary longitudinal and cross-sectional view of another absorbent core structure of the present invention comprising a bottom primary layer formed from a plurality of heterogeneous, sub-layered laminates arranged to provide an uneven, zonal basis weight in said lower primary layer. ;

shows an exemplary embodiment of a further absorbent core structure according to the present invention in longitudinal and cross-sectional view, comprising a lower primary sheet formed from heterogeneous laminate, wherein the distribution of superabsorbent material is arranged to provide a non-uniform, zonal base weight of superabsorbent material;

Giant. 10 is a schematic illustration of a test apparatus for determining specific parameters of superabsorbent material;

Giant. 11 shows an exemplary embodiment placed in a weight tank of a plate piston, in cross-section;

cylinder assemblies applied to

Giant. 12 shows an exemplary embodiment of a cylinder assembly disposed in a reservoir with a connecting rod arranged for tapping the plate piston, in cross-section;

Giant. 13 shows an exemplary embodiment of a cylinder assembly with a weight applied to a plate piston disposed in a vacuum fixture in cross-section;

Giant. 14 illustrates an exemplary embodiment of a cylinder assembly disposed in a vacuum fixture, in cross-section.

DETAILED DESCRIPTION OF THE INVENTION

The following is a description of the various aspects and embodiments of "fefefe".

The present invention will be embodied in the context of a disposable absorbent article, such as a disposable baby diaper. However, it should be understood that the present invention may also be applied in conjunction with other articles such as diapers; women's protective menstrual articles, adult incontinence absorbent articles, pads and the like, which may be formulated as disposable articles. Typically, said disposable absorbent articles, such as disposable sanitary absorbent articles, are intended for limited, short-term use only and are not intended to be laundered or otherwise cleaned for reuse. For example, a disposable diaper during the functional application of the present invention refers to a self-fastening system means a system comprising cooperating elements configured to engage with each other so as to provide the desired fastening.

after its contamination throws into waste.

by

In a reliable and solid context

According to the present invention, there is provided an absorbent core system comprising, as part of a plurality of sheet portions, capable of providing a significant increase in void volume size and efficiency, improved permeability, and improved suction efficiencies in a predetermined acquisition zone. The absorbent system, and in particular the absorbent core of the system, is substantially capable of regenerating the desired void volume size by transferring the liquid away from the acquisition zone, for example, by the function "fe feef" fe feef · fe feefefefe

• fefe • fefe * · fefefe fefe · fe fefefefe • fe · · soaking or other mechanisms. The drained liquid may preferably be collected in the layer portion of the absorbent core that is intended to provide the desired, relatively large distribution of the acting liquids, while the layer portion intended to provide adequate void volume and fluid suction may be maintained in a relatively low saturation state. In the vast majority of cases, the layered portions may be configured with relative basis weights or concentrations of superabsorbent materials and arranged such that suitably cooperating materials with appropriate, appropriate capabilities will be capable of being incorporated into the system and providing reliable functional efficiency. However, it has been found that certain specific combinations of these materials, compared to others, are capable of providing substantially improved functional efficiency and performance. In addition, it should be taken into account that the basis weights or other capabilities of the individual components of the materials are possible, in order to optimize costs and other user parameters, or to ensure the desired distribution and distribution of absorbed liquid, in specific areas or zones of the absorbent structure (e.g. front, face layer depending on the back, reverse side).

According to the present invention, the absorbent layered portions can be significantly configured to cooperate in a manner in which the displacement and location of the absorbed liquid is preferably performed in one or more predetermined or determined layered portions. Said localization of the absorbed liquid into the volume of the designated layered portion is capable of increasing the potential of the layered portion in terms of displacement and distribution of the liquid by capillary action, »9 9 9 9

As a result, relatively higher levels of saturation and absorption of the increased amount of liquid are achievable in the predetermined layer portion.

The absorbency of the absorbent system, in particular the absorbency of the absorbent core, can be maintained at a conventional level or improved by maintaining the primary, absorbent layer portion of the absorbent system at low saturation levels over the maximum number of liquid impacts on the absorbent article compared to standard absorbent systems. while providing optimal suction efficiency by adequately controlling the properties of the composite structure. The relatively low level of liquid saturation in said intake layer provides an adequate void volume for subsequent liquid impact, as well as high permeability, and thus an increased intake rate of the absorbent system as a whole. Advantageously, the suction layer portion can be configured to provide reasonably high levels of capillary stress to provide adequate controlled fluid displacement control while substantially eliminating liquid leakage. Due to this low saturation, the layer portion desirably additionally used for the separately provided alignment section or layer, and can provide additional suction functional undesirable is a suction complement to the suction alignment layer.

ability that is the ability provided by the material

In specific embodiments, the absorbent sheet portion may be disposed on the skin facing the wearer side of the absorbent structure, and may be configured not to extend over the entire surface area of the absorbent structure.

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0 0 0 · · 0 as a whole. Accordingly, the primary skin-facing layer portion is used as a suction layer portion, and at the same time is not used as a highly saturable absorbent layer portion. In addition, this arrangement permits the placement of the intake layer portion in substantially direct contact with the incoming feed liquid, thereby allowing a much more direct access of the incoming liquid and a more efficient aspiration performance.

The layered portions may be designed, singly or in combination, to provide an improved balance of effectively performing liquid suction and distribution functions, especially water-based liquid suction and distribution. Improved efficacy can be ensured, for example, by modifying the physical and / or chemical composition of the materials of the individual components of the absorbent structure or by modifying the body configurations of the components. .

Standard fibrous materials and superabsorbent polymer composite materials (SAP) used to form conventional prior art absorbent articles, such as diapers, are capable of providing conventional combinations of functions such as aspiration, distribution, and retention retention. However, there is a continuing need to provide more functionally effective materials and improved absorbent systems and structures that, in combination, are capable of providing increased levels of efficient suction, distribution and deployment, and retention retention of the acting fluid. In order to provide improved resistance to unwanted leakage, improved materials are incorporated into the absorbent system of the present invention, wherein the materials exhibit improved properties and capabilities in the absorbent system. at least one of the functional areas or zones. These measures may result in improved complex functional efficiency of the absorbent system as a whole.

The suction function can be adjusted and controlled, for example, by control parameters, including the size of the fibers and particles of the materials present in the respective layer, the voidness of the layer, the basis weight of the layer, and the qualitative and quantitative composition of the layer. The distribution can be adjusted and controlled, for example, by appropriate selection or by influencing control parameters, including the size of fibers and particles of the individual components of the materials used, the amount of wetting angles of the materials used, the surface tensions of the liquids, and the basis weight of the materials used.

For the purpose of further absorbing properties to improve the desired balance, a number of other layered portions, when acting in significant manner, have been determined to provide parameters that can enhance the combined functional effectiveness of each other and consequently provide an improvement in the complex functional efficiency of the absorbent system as a whole. Said parameters include a flow conductivity setpoint and a liquid absorbency setpoint provided by the absorption system. Another complementary factor to assess the overall performance of the absorbent system is the combined conductivity / absorbency value.

The flow conductivity represents a value that is

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Based on the physical properties of the absorbent materials, and in particular those absorbent materials arranged in the receiving zone of the absorbent system, and is related to the absorbency provided through the structure of the absorbent core. It is desirable and desirable if the flow conductivity is not less than about 2.5 x 10 ^-6 cm ³ . Alternatively, to provide improved efficiency, the flow conductivity value is not less than 3.10 ^-6 cm ³ , and optionally is not less than 3.5.10 ^-6 cm ³ . According to other aspects of the present invention, the flow conductivity may be up to about 5.10 ^-6 cm ³ . Alternatively, in order to provide improved efficiency, the flow conductivity may be up to about 7.10 ^-6 cm ³ , and optionally the flow conductivity may be up to about 9.10 ^-6 cm ³ , or greater.

The potential wicking capacity of the liquid (or the wicking capacity of the liquid) is a functional performance parameter that relates to the amount of liquid removed and displaced from the absorption zone of the absorbent structure described above during the vertical soaking. This value represents the ability of the absorbent structure to remove and displace the applied liquid from the acquisition zone between the individual impacts of the liquid, for which purpose the at least one layer portion of the absorbent system is configured to provide a desired value of potential liquid wicking. Suitably and desirably, the at least one layer of the absorbent system, in particular the at least one primary layer portion of the absorbent core, is capable of providing a liquid wicking value of not less than at least about 10%. Alternatively, if it provides a liquid wicking value of not less than about 15% and optionally a value of not less than

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than about 20%. According to other aspects of the present invention, the absorbent system is capable of providing a liquid wicking value of up to about 60%. Alternatively, to provide improved efficiency, the liquid wicking value provided may be up to about 65%, and optionally may be up to about 70% or more.

The combined conductivity / absorbency value (C) of the absorbent system may be at least about 14 x ^{10 6} cm ³ . Alternatively, in order to provide improved efficiency, the combined conductivity / absorbency value may be at least about 15. 10 ^-6 cm ³ , and optionally may be at least about 16.10 cm ³ . In other embodiments, the combined conductivity / absorbency value may be at least about 18.10 &quot; cm &lt; ^{3 &gt}; to provide improved performance.

In embodiments of absorbent articles having a small thickness and narrowed crotch regions, the receiving zone of the article, in its dry state, typically does not exhibit sufficient void volume available to effectively absorb the initial impact of a liquid, such as urine. Said gap volume deficiency can be compensated by incorporating a specifically configured superabsorbent polymer material (SAP) in an amount sufficient to absorb the feed liquid during the duration of its impact. The SAP incorporation system is configured to absorb and maintain the amount of liquid to be absorbed during its impact so as to provide the desired leak resistance.

Although some of these parameters have been individually described in detail above, there is still a security problem

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99 an effective combination of these parameters and the properties described by them in a single composite structure while maintaining the desired user properties. To address the problems of liquid absorption, the solution to these problems has hitherto been directed to the requirement of the presence of a relatively low amount of superabsorbent polymeric materials (SAP), either in the absorbent structure as a whole or in individual layers arranged therein. However, the use of a low SAP concentration in the absorbent article volume may, due to the need to provide the desired absorbency and retention capacity, lead to an excessive increase in the absorbent article thickness. For this reason, an attempt has been made to create an absorbent structure in which one absorbent layer exhibits a low SAP concentration to enhance liquid wicking, while maintaining a high concentration in the other absorbent layer to achieve the ultimate thin absorbent article having the desired absorbency and retention capacity. SAP. Such systems, however, do not provide the desired levels of functional efficacy since the treating liquid may preferably be transferred to areas containing relatively higher concentrations of SAP. In this state, the amount of liquid remaining in the layer portion containing the relatively lower SAP concentration may be insufficient to provide the desired levels of water absorption.

In order to overcome these drawbacks, according to a specific aspect of the present invention, the absorbent system may comprise a controlled proportion of superabsorbent polymer material (SAP). By using a controlled SAP fraction in the absorption system, for example a selected, slightly reduced SAP fraction, it is possible to maintain a high liquid concentration in the fibrous structure as determined by the distribution.

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44 even if said distribution layer portion contains a selected amount of SAP. In specific embodiments, the controlled reduced proportion of SAP is primarily located in a layer portion other than a distribution layer portion. As a result, the low SAP portion may be in a saturated state while maintaining the overall absorbency of the thin absorbent article at the desired high level. It is contemplated that other alternative mechanisms other than the inclusion of a reduced proportion of SAP in the absorbent structure may be used to provide the desired absorbency distribution and different liquid absorption concentrations between the selected layer portions. The desired absorbency distribution can be ensured, for example, through the selective configuration of the relative wettability and / or density of the layered portions.

Referring to FIG. 1 and 2, it can be seen that the absorbent composite system 26 of the present invention comprises a buffer layer 84 to compensate for the impact of a liquid, and a structural absorbent pad or core 30. The absorbent core 30 has a multilayer structure of absorbent layered portions. selected and configured by adjusting and balancing the capability of receiving and soaking the acting fluid to provide enhanced performance against unwanted leakage.

Generally speaking, the absorbent core 30 of the present invention begins (taken in the direction of liquid displacement from the closest to the user &apos; s skin facing the surface area &gt; 00 00).

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The first absorbent layer comprising the superabsorbent material together with an arbitrary component necessary to maintain the integral integrity of said layer as a whole during functional action . This first layer is required to contain a minimum amount of superabsorbent material that is not less than about 5% by weight. The absorbent core 30 is terminated (taken in the direction of liquid displacement from the closest to the user's skin facing the outer surface of the absorbent article to its exterior, at the furthest distance from the user's skin facing surface) with the last absorbent layer disposed immediately in front of the substantially liquid impermeable a layer which forms a protective barrier against undesirable leakage of liquid from the absorbent article. Accordingly, the absorbent core 30 in the illustrated embodiment comprises a first primary absorbent layer 48, an outer or outer shell layer 28 or 36, and the respective components sandwiched therebetween. In addition to the absorbent core, the absorbent article further comprises a topsheet 24, a leveling layer 84 that does not contain superabsorbent material, and a backsheet 22.

The appropriate balance of fluid acceptance and wicking capabilities can be represented by various determining parameters, such as flow conductivity value, liquid wicking potential value, basis weight, particle size, relative fiber content, and the like, as well as combinations thereof. . The value of the flow conductivity of the absorbent material is related to the available void volume and structure permeability during • *. ·. * ·. · ····. The effect of liquid characterizing the different levels of saturation, typically occurring in normal functional use . In order for the absorbent system to provide improved functional efficiency, it is necessary to allow the acting liquid to enter the absorbent structure at a rate as close as possible to the rate at which the acting liquid is introduced into the absorbent structure. For the purpose of characterizing the suction potential of the absorbent core 30 as a whole, and in particular the suction potential of the absorbent system 26, a flow conductivity value may serve. In addition, an important parameter is the displacement of the acting liquid away from the inlet zone, the purpose of which is to accumulate liquid in the distant regions of the absorbent and, secondly, to regenerate and prepare the inlet zone to receive the next burst with much greater efficiency.

The absorption capacity of the absorbing liquid from the acquisition zone between two successive impacts of the liquid may serve.

For structural purposes

Referring to FIG. 2 and 2A, the absorbent core 30 has an overall length 66 of the composite absorbent core, an overall width 68 of the composite absorbent core, a total thickness 70 of the composite absorbent core, a crotch width 58 of the absorbent core, and a predetermined foremost end edge of the absorbent core. The delimitation of the foremost end edge serves to determine its location on the front waistband portion of the absorbent article. As can be seen in FIG. 2, the assembly of individual components of the absorbent core 30 extends over and overlaps the entire determined range of the absorbent core. The individual components or layers, and optionally the partial layers, can extend over the entire absorbent range to provide the desired performance.

fefefe fefefefe fe · f · fe fefe fefe fe · fefe fe · fefe fe · fe fefe kernel. Moreover, each of said individual layers has individual dimensional dimensions. In the example embodiment shown, for example, the first layer portion 48 has a first thickness (height) 72, a first length 73 and a first width 74. The second layer portion has a second thickness (height) 75 / a second length 66 and a second width 68.

Referring to the overall length 66 of the absorbent core, the designated acquisition zone 52 of the absorbent structure for absorbing the applied liquid is a portion of the absorbent core that begins on a transversely extending transverse line positioned at a position within 24% of the total length 66. an absorbent core from the foremost end edge of the absorbent core, and extends to a second transverse direction extending transverse line positioned at a position within 59% of the total length 66 of the absorbent core from said frontmost end edge. For example, in the illustrated embodiment, the absorbent core acquisition zone may be an area of the absorbent structure that begins on a transverse direction extending approximately 3.5 inches (89 mm) from the foremost end edge of the absorbent core and extends in the transverse direction. a spacing line, spaced approximately 8.5 inches (126 mm) from said foremost end edge.

Increasing the flow conductivity by increasing the volume of the absorbent core structure has been rejected as undesirable because the absorbent articles having a narrow crotch region have experienced an excessive increase in the thickness of the finished product. As a result, there remains a need to provide absorbent systems with a configuration that is capable of providing the desired suction efficiency, represented, for example, by the value of flow conductivity while maintaining a small thickness of the absorbent core 30 and at the same time a small thickness of the absorbent system 26. It is desirable that the absorbent core 30 have a total thickness of not more than about 6 mm in the dry state. Alternatively, the absorbent core may have a thickness of not more than about 5.3 mm and optionally a thickness of not more than about 5 mm such that the absorbent core is capable of providing the desired functional effectiveness. According to another aspect of the present invention, the absorbent core 30 may have a dry thickness of no more than about 25% of the width of the crotch region of the absorbent core. Alternatively, the absorbent core 30 may have a thickness that is not greater than about 20% of the width of the crotch region, and optionally a thickness that is not greater than about 15% of the width of the crotch region so that the absorbent core is capable of providing the desired functional effectiveness. For the purposes of the present disclosure, the crotch region width of the absorbent core is determined as the narrowest (smallest) dimension of the crotch region in the transverse direction contained in the absorbent core receiving zone.

Further, it is desirable for the absorbent system 26 to have a total dry thickness of not more than about 6 mm in the dry state. Alternatively, the absorbent system may have a thickness of not more than about 7.3 mm, and optionally a thickness of not more than about 7 mm, such that the absorbent system is capable of providing the desired functional effectiveness. According to another aspect of the present invention, the absorbent system 26 may have a thickness that is no greater than about 30% of the width of the crotch region of the absorbent system. Alternatively, the absorbent system 30 may have

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In the dry state, a thickness of not more than about 25% of the width of the crotch region and optionally a thickness of not more than about 20% of the width of the crotch region so that the absorbent system is capable of providing the desired functional effectiveness.

For purposes of the present description, the dry state is measured at a controlled limited pressure of 0.2 psi (1.38 kPa).

According to a further aspect of the present invention, the low-section absorbent system 26, and in particular the absorbent core 30, may have a crotch region 54 intended to be positioned between the wearer's legs, the narrowest (smallest) dimension of the crotch region transversely located in the receiving zone 52 crotch area. In view of this, an adult absorbent article (intended for functional use by adults, i.e., over the age of 13) may, in the dry state of the composite absorbent structure, exhibit a minimum width of the crotch region 54 in the transverse direction not greater than about 5, 5 inches (about 14 cm). Alternatively, such a product may have a minimum width of the crotch region 54 that is not greater than about 4.5 inches (about 11.4 cm), and optionally may have a minimum width that is not greater than about 3.5 inches (about 8.9 cm) ) to achieve the required assurance of improved fit and ease of application. An absorbent article intended for juveniles (intended for functional use by minors under the age of 13) may, in the dry state of the composite absorbent structure, exhibit a minimum width of the crotch region 54 in the transverse direction of not more than about 4 inches (about 10 cm). Alternatively, such a product may have a minimum region width of 54 &quot; 0 &quot;

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the crotch that is not greater than about optionally may have a minimum of about 2 inches (about 5.1 cm) to achieve the desired assurance of improved fit and comfort in application.

Further, for the functional purpose of the absorbent system, it is important to remove the acting liquid from its receiving zone 52 so as to effectively prevent excessive saturation of said liquid in the zone and consequently undesirable liquid from the absorbent article. The ability of the absorbent system to move or distribute the acting liquid from the acquisition zone may be represented by the value of the potential absorbability of the liquid provided by the absorbent system. The value of potential liquid wicking capacity is related to the amount of liquid the absorbent system is able to move from the acquisition zone when the acquisition zone exhibits a liquid loading / saturation level of 1.0 grams of liquid per centimeter of the acquisition zone of the composite absorbent structure. Accordingly, the present invention provides a specific layered absorbent system having a low thickness, narrowing in the crotch region and having a small volume.

The layered portions in the absorbent system are configured to include a first layered portion facing the user's skin, which may have different shape configurations suitable for the purpose, but typically has a size not greater than the outer range of the second layered portion. The first topsheet is capable of maintaining saturation at low inches (about 7.6 cm) and a width that is not greater when the absorbent article is in use when used in combination with the second, bottomsheet. Flow conductivity, selectable level and high value at the same time Second, lower layer part may be shaped, for example, hourglass or T-shaped, and is configured to efficiently distribute and displace the acting liquid from the acquisition zone of the absorbent composite structure. In particular, the second, lower layer portion is capable of providing the desired liquid wicking potential values, which can be determined using the Liquid Wicking Potential Determination Procedure described in detail below.

Referring to FIG. 1, IA and IB, the present invention may provide a disposable sanitary absorbent article, for example, a diaper 20 having a longitudinally extending longitudinal direction 86 and a transversely extending width direction 88. The absorbent article comprises a first waistband portion, for example a back waistband portion 40, a second waistband portion, for example a front waistband portion 38, and an intermediate crotch region 42 interconnecting said first and second waistband portions. The front waist panel 38 is provided with a pair of transverse opposite side end regions 118 of the front waist panel, a rear waist panel 40 is provided with a pair of transverse opposite side end regions 116 of the rear waist panel, and an intermediate crotch region 42 provides a respective crotch region an absorbent article which is positioned between the wearer &apos; s legs for functional application.

Giant. 1 illustrates an exemplary embodiment of a disposable diaper 20 of the present invention shown in a fully unfolded, uncontracted state (i.e., in a state in which all elastic elements causing shirring are contained in the absorbent article).

• 0 0 0 0 0 0 0000 0 0

0 · 0 0 · · 00 00 ® · * · download and download, removed). Some parts of the absorbent system structure are partially removed due to the more obvious appearance of the diaper diaper, and the diaper is shown in a view of the surface area closest to the skin of the wearer facing layer. The outer edges of the diaper define through its longitudinally extending side end edges 110 and transversely extending front end edges 112 its outer circumferential boundary. Additionally, the side end edges 110 define a leg cutout or leg region, and optionally are curved or otherwise contoured.

The liquid-permeable topsheet 24 is laminated in the front to the substantially liquid-impermeable backsheet 22, and between the topsheet and backsheets 24 and 22 there is a functionally arranged and fastened absorbent system. By way of example, the embodiment shown has an absorbent system 26 that includes a buffer layer 84 for counteracting the impact of a liquid and a retention portion for maintaining and accumulating the liquid. The retention portion of the absorbent system includes an absorbent core 30. In the illustrated embodiment, the alignment layer 84 is a layer disposed between the absorbent core and the topsheet 24. Conveniently, other arrangements may be used. For example, the alignment layer 84 may be optionally positioned between the absorbent core and the backsheet 22, or directly on the user-facing skin surface of the topsheet.

The absorbent article further typically comprises elastic or elastomeric elements, such as leg elastic elements 34 and waist elastic elements 32, and an aligning element.

the layer 84 is arranged in functional fluid communication with the retention portion of the absorbent system. The topsheet 24, the backsheet 22, the absorbent core 30, the alignment layer 84, and the elastic members 34 and 32 may be assembled together into various diaper configurations known in the art. Additionally, the diaper may comprise a plurality of control retention flaps 82 and side panels 90 that may be elasticized or otherwise treated to be elastic.

diapers ”, submitted and brief content

Examples of such absorbent articles that include elasticized side panels and optionally configured fastening tabs are described in U.S. patent application Ser. 168,615, T. Roessler et al., Entitled Functional Accessories for Wrap

December 16, 1993 (see verified annotation

No. 10,961). Various technological processes for making the desired fastening systems having correspondingly appropriate functional effects are further described in U.S. Pat. No. 5,399,219, T. Roessler et al., Entitled Method of Making a Fastening System for Functional Accessories of a Diaper, published March 21, 1995 (see, verified annotation and brief contents no. 11,186); in U.S. patent application Ser. 286,086, D. Fries, entitled Method for Assembling Elasticized Grip Flaps, filed Aug. 3, 1994 (cf. Verified Annotation and Brief Content No. 11,169), which was published as U.S. Pat. 5,540,796; and U.S. patent application Ser. 08 / 415,383

D. Fries, entitled Method of Assembling a Laminated Tape, filed April 3, 1995 (cf. Verified Annotation and Brief Content No. 11,950), which was published as U.S. Pat. 5,595,618. Full descriptions of the above-described documents are hereby incorporated by reference into the present invention and become

- 29 • · * 0 4 • · · · 0 9 ·· φ

9 9 9 9 9 0 is thus part of it (without limiting its scope in any conflicting manner).

round shaped quadrangle, shape 1 '

The diaper 20 is as can be seen from its exemplary representation in FIG. 1, generally delimited by the longitudinally extending longitudinal direction 86 and the transversely extending longitudinal direction 88. The diaper may have any desired, for example, an hourglass shape (middle tapered shape) or a T shape. T form the front waistband portion of the diaper or, alternatively, may form the back waistband portion of the diaper.

Configuration

The topsheet 24 and the backsheet 22 may generally have the same surface area, and may have dimensions, i. length in the longitudinal direction and width in the transverse direction, which are generally generally greater than and which extend over and beyond the corresponding dimensions, length and width of the absorbent system 26 to form corresponding portions of boundary side edges 110 and boundary end edges 112 that they extend around the boundary end edges of the absorbent system. The topsheet 24 is mated with and laminated to the backsheet 22 to define the perimeter of the diaper 20. The diaper waistband portions 38 and 40 include those sections of the diaper that during its functional application either completely or partially overlap or surround the wearer's belt or its lot close to his crotch. An intermediate crotch region 42 is formed between these waistband portions 38 and 40 and is joined together to form a portion of the diaper which is conveniently disposed between the wearer &apos; s legs and overlaps his groin in the groin area during functional application of the diaper. Thus, the intermediate crotch region 42 is that area of the diaper exposed to repeated fluid impact, typical and characteristic of using the diaper or any other disposable absorbent article.

The backsheet 22 may typically be located outside the surface of the composite absorbent system 26 and may consist of a liquid pervious material, but it is desirable to be formed of a material configured to be substantially impervious to liquids. Accordingly, the backsheet may be characterized, for example, by a thin plastic film or other flexible and liquid impermeable material which can be used for this purpose. By the term flexible (materials) used in accordance with the description of the present invention is meant materials that are compliant and which will readily conform to the general shape and contour profile of the user's body. The function of the backsheet 22 is to prevent wetting and eventual contamination of articles such as bed linen or user underwear in contact with diaper 20, body exudates contained and retained in the composite absorbent system 26. In specific embodiments of the present invention, the backsheet 22 may the backsheet 22 comprises a thin film, such as a thin polyethylene film, having a thickness ranging from about 0.012 to about 0.051 millimeters (0.5 to 2.0 mils). For example, the backsheet sheet may have a thickness of about 1.25 mils.

00 * · • · 0 • · 0 · • 0 • · 0 0 0 0 0 0 · • · • · 0 · • 0 0 0 • · · 0 0 0 0 00 0 0 0 0 0 0

Alternative embodiments of the backsheet may consist of a layer of woven or nonwoven fibrous fabric, which may either be wholly or partially formed or processed to achieve desired levels of liquid impermeability in selected areas adjacent to or disposed adjacent the absorbent core. Thus, for example, the backsheet may comprise a gas permeable nonwoven fabric layer laminated to a thin polymeric film layer. Other examples of fibrous, backsheet-like materials may include a stretch-tapered or stretch-stretch laminate consisting of a blown polypropylene film of 0.6 mils (0.015 mm) and a spunbonded polypropylene material with a basis weight of 0.7 ounces per inch. square yard (23.8 grams per square meter) (fiber with a weight denier of 2 denier). This material forms an outer protective layer of diapers known as HUGGIES SUPREME, available from Kimberly-Clark Corporation. Typically, said backsheet 22 provides an outer protective layer for the absorbent article. Optionally, however, the absorbent article may comprise an external protective. the layer as a separate, separate component, which in addition is attached to the backsheet.

The backsheet 22 may alternatively include a microporous breathable material that explicitly permits the penetration of gases such as water vapor from the composite absorbent system 26 while substantially eliminating and preventing the passage of liquid body exudates through the backsheet. Breathable bottom back * · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · for example, the layer may consist either of a thin microporous polymeric film or of a nonwoven fabric that is or is modified accordingly to achieve the desired levels of impermeability to the coated liquids. A suitable microporous film useful herein may be, for example, PMP-1, commercially available from Mitsui Toatsu Chemicals, Inc., with a commercial office in Tokyo, Japan; or XKO-8044 polyolefin film, marketed by 3M Company, Minneapolis, Minnesota. In addition, the backsheet may be further subjected to a cladding or other technology providing, in the finished state, a surface relief or a matt finish having an aesthetically acceptable and pleasant external appearance.

In various configurations of the present invention in which the components of an absorbent article, such as backsheet 22 or regulatory containment flaps 82, are formed to both exhibit gas permeability and at the same time penetration resistance and limited permeability of water-based liquids, be a liquid-resistant material arranged to be capable of withstanding the pressure exerted by a static height of 45 cm water column without causing any substantial leakage or leakage of the applied liquid. A suitable technological procedure for determining the material's resistance to liquid penetration is described in Federal Test Standard FTMS 191 Test Method 5514, published December 31, 1968.

The size and / or extent of the backsheet 22 is characterized by the size of the absorbent system 26 and the absorbent core 30, respectively, and the specific size selected.

1119

911 111 · diaper configuration. The backsheet 22 may have, for example, a generally T-shaped, generally I-shaped or modified, mid-tapered hourglass configuration, with a predetermined distance, such as a distance of about 1.3 cm to about 2, 5 cm (from 0.5 to 1.5 inches), extending beyond the end edges of the absorbent core 30 to form outwardly extending side and front end edges.

The topsheet 24 is a skin-facing surface that is in contact with the skin, is supple, soft to the touch, and does not cause skin irritation. Further, the topsheet 24 may exhibit less hydrophilic capability than the composite absorbent system 26 while being sufficiently porous to provide liquid permeability to explicitly allow liquid to readily pass through its bulk thickness into the volume of the composite absorbent system 26. Corresponding topsheet 24 it may be formed from a wide variety of fibrous materials, such as porous foam material, cross-linked foam material, perforated plastic film, natural fibrous materials (e.g., wood or cotton fibers), synthetic fibrous materials (e.g., polyester or polypropylene fibers), or mutual a combination of natural and synthetic fiber materials. The topsheet 24 is specifically used to assist in insulating the wearer &apos; s skin from liquids that are retained and accumulated in its composite absorbent system 26.

Various types of woven or nonwoven fabric can be used to form the topsheet 24. Top ···· · · · «« 9 9 · 9 9 9 9 9 9 9

9 9 9 9 9 9 9 9 9 9 • 9 9 9 9 9 9 9 9 9

999 9999 99 9 9 99 99 the facing layer may be formed, for example, of blown or spunbonded webs or nonwovens consisting of, on request, selected fibers, and may furthermore be formed of carded webs, wet-spun webs by stitching the fibers of the reinforced flat fabric or the like, as well as combinations thereof. Said fabrics may consist of natural fibers, synthetic fibers or combinations thereof. Optionally, the topsheet may comprise a cross-linked material or a perforated film as part.

For the purpose of interpreting the present invention, the term &quot; nonwoven &quot; refers to a web of fibrous material that is formed in a manner other than using textile weaving or knitting. The term &quot; woven fabric &quot; as used herein refers to all woven, knitted and nonwoven fibrous materials, flat fabrics or webs, and combinations thereof.

The topsheet webs may consist of a substantially hydrophobic material, the hydrophobic material optionally being treated with either a surfactant or other suitable technology known in the art to achieve the desired wettability and hydrophilic properties. In a specific embodiment of the present invention, the topsheet 24 is formed of a spunbonded, spunbonded polypropylene sheet fabric, consisting of fibers having a yarn weight of from about 2.8 to about 3.2 denier, treated as a web and has a basis weight of about g / g. m ² and a density of about 0.06 g / cm ² . This fabric is subjected to a surface treatment using a 0.28% solution.

• 4 ·· «0

0 • 0 0 0 0 · 00 ·· •• 00000 00 · Φ 0 · .4 · Triton X-102 surfactant. The surfactant may be applied to the surface of the web by any conventional means or technology, for example by spraying, printing, brushing or the like.

The topsheet 24 and the backsheet 22 are joined or otherwise coupled together in a functional manner. As used in the present description, the terms used to refer to each other include both configurations in which the topsheet 24 is bonded to the backsheet 22 directly by directly attaching said topsheet 24 to the backsheet 22 as well as the configurations in which the topsheet 24 is attached to the backsheet. a layer 24 with a backsheet 22 joined indirectly by attaching the topsheet 24 to the interposed components, which are then successively, one after the other, attached to the backsheet 22. The topsheet 24 and the backsheet 22 may be attached to the backsheet. coupled to one another, for example, around the circumference of the diaper by means of attachment means (not shown in the accompanying drawing), such as adhesive bonds, ultrasonic bonds, thermal bonds, lamellas, stapling or any other Fastening means known in the art as well as combinations thereof. For example, such as a uniformly arranged compact adhesive layer, an adhesive layer arranged in an embossed configuration, a spray applied adhesive layer or an adhesive layer formed by a set of individual, spaced strips, segments or dots may be used to attach the topsheet 24 to the backsheet 22. adhesives. Persons familiar with the state of the art must be absolutely clear about the technique, The fastening means mentioned above can be used for correspondingly connecting and fastening to each other the various other components or integral parts of the absorbent articles described herein.

An exemplary embodiment of an absorbent article is provided with a composite absorbent system that includes, as part of, a buffer layer 84 to counteract the impact of a liquid and a retention portion for retaining and storing absorbed body fluids and other exudates. According to specific aspects of the present invention, the retention and storage portion is provided by the absorbent core 26 shown, comprising a plurality of layers formed of specifically selected fibrous materials and particles of a highly absorbent material. The illustrated absorbent core composite absorbent system is conveniently positioned and sandwiched between the topsheet 24 and the backsheet 22 to form the diaper 20 as a whole. In this state, the composite absorbent system exhibits a structure which generally provides compressibility and conformability, while not causing undesirable irritation to the skin surface of the wearer while being able to absorb and retain liquid body exudates.

Depending on the type of individual configurations of the absorbent article of the present invention, different types of wettable hydrophilic fibrous materials may be used to form the individual components of the absorbent article. Examples of such useful fibrous materials include naturally occurring organic fibrous from inwardly wettable fiber materials; synthetic fibrous materials consisting of synthetic cellulose or derivatives thereof, for example, regenerated cellulose fibers; inorganic fibrous materials consisting of an inherently wettable material, for example glass fibers; synthetic fibers formed from naturally wettable thermoplastic polymers, in particular polyester or polyamide fibers; and synthetic fibrous materials formed from non-wettable thermoplastic polymers, in particular polypropylene fibers. Said fibrous materials may be treated to improve hydrophilic properties, for example either by treatment with silica or by treatment with a material having an adequate hydrophilic fraction and cannot be easily removed from the treated fibers, or by sheathing non-wettable hydrophobic fibers with a hydrophilic polymer protective coating. during or after the formation of these fibers. For the purpose of forming the absorbent article of the present invention, or individual parts thereof, it is also contemplated to use different mixtures of different types of the aforementioned fibrous materials based on the respective requirements.

cellulosic materials

As used herein, the term hydrophilic (material) refers to fibrous materials or surfaces formed from such fibrous materials that are wettable in contact with a water-based liquid. The degree of wettability of said materials can be described based on the wetting angles and surface tension of liquids and respective materials. Test apparatuses and related test procedure technologies suitable for measuring and determining the wettability of individual fibrous materials or mixtures • 0

0 00 0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 for surface tension measurements, or other analogous devices. Based on testing using said test apparatus, fibrous materials having a liquid wetting angle of less than 90 ° are referred to as wettable, while fibrous materials whose liquid wetting angle is greater than 90 ° are referred to as non-wettable.

Specifically, the absorbent core 30 of the composite absorbent system may comprise one or more fibrous matrices, such as, for example, a fabric of natural fibers, synthetic fibers, and the like, as well as combinations thereof. It is desirable that said fibrous materials be hydrophilic, either due to their inherent nature or through the effects of processing thereof to enhance hydrophilic properties in a conventional manner. Specific arrangements may include a fibrous matrix consisting of fibrous fluff technical cellulose. It will be appreciated from the foregoing that each of the primary layer portions, i.e., the first primary layer portion 48 and the second primary layer portion 50, may comprise either the same fiber matrix types or, in contrast, different fiber matrix types.

According to specific aspects of the present invention, the respective fiber matrices of the primary layer portions 48 and 50 may be mixed with or otherwise imparted to the particles of highly absorbent material. The fibrous materials are arranged in an absorbent matrix in the selected layer or layers, and it is desirable that each of said primary layers 48 and 50 may comprise at least one fibrous material combined.

· 4

4 4 4

4 4 4

4 4 4 • 4 4

4 4 4 4 4 • 4

4 4 4 ·

444 4444 4 44 with particles of highly absorbent material. For example, in specific embodiments, the defined absorbent core layers 30 may comprise a mixture of superabsorbent hydrogel-forming particles and natural fibers, synthetic meltblown polymer fibers, or a mixture of superabsorbent hydrogel-forming particles and a combined fibrous material consisting of a mixture of natural fibers and / or synthetic polymer fibers. Said particles of superabsorbent material may essentially form either a homogeneous mixture or an unevenly mixed mixture with the hydrophilic fibrous materials. For example, the concentration of superabsorbent particles in the composition may have a discontinuous gradient, or do not vary smoothly through substantially a significant portion of the thickness of each absorbent structure layer (Z-axis), with lower concentrations closer to the user's skin facing surface and relatively higher. facing the wearer's garment facing the surface of the absorbent structure. Suitable and suitable Z-axis concentration gradient configurations are described in U.S. Pat. No. 4,699,823, to Kellenberger et al., Issued Oct. 13, 1987, the entire disclosure of which is hereby incorporated by reference into the present invention and thus becomes part of the description of the present invention (without limiting its scope in any way). Alternatively, the concentrations of superabsorbent particles configured with a discontinuous gradient through a substantially significant portion of the thickness of each layer of absorbent structure (Z-direction) with higher concentrations closer to the user's skin facing surface and relatively lower concentrations outside the wearer facing surface structure. The superabsorbent particles may further be arranged to form a generally separate, separate layer disposed within the fibrous interior.

0 9 999 9 0 9 · φ · · 0 0 · · * · ·

* Matrices made of hydrophilic fibrous materials. In addition, the absorbent structure may comprise two or more different types of superabsorbent material, which are optionally arranged at different locations within or on the surface of the respective fibrous matrix.

The highly absorbent material may include gel-forming absorbent materials, such as superabsorbents. These gel-forming absorbent materials can be natural, modified natural and synthetic polymers and materials. In addition, the gel-forming absorbent materials may be inorganic materials, for example, silica gel, or organic compounds, for example, cross-linked polymers. By cross-referenced is meant the consequence of using any means for forming normally water-soluble, substantially water-insoluble but swellable layers. Said compositions may include, for example, network bonds, crystalline domains, covalent bonds, ionic complexes and bonds, hydrophilic bonds, for example hydrogen bonds, hydrophobic bonds, or bonds via the Van der Waals forces.

Examples of synthetic absorbent gel forming polymeric materials include the alkali metal and ammonium salts of polyacrylic and polymethacrylic acids, polyacrylamides, polyvinyl ethers, copolymers of maleic anhydride with vinyl ethers and alphaolefins, polyvinylpyrrolidine, polyvinylmorpholinone, polyvinyl alcohol, mixtures thereof and copolymers thereof. Other suitable polymeric materials useful in the manufacture of the composite absorbent system include natural and modified natural polymers, such as, for example, hydrolyzed polymers. Acrylonitrile graft starch, acrylic acid graft starch, methyl cellulose, hydroxypropyl cellulose, and natural rubber compounds, such as alginates, xanthan gum, locust bean gum etc. In addition, mixtures of natural and wholly or partially synthetic absorbent polymeric materials can be used for the purposes of the present invention. Other useful gel forming absorbent materials are described in U.S. Pat. No. 3,901,236, Assarsson et al., Issued Aug. 26, 1975. Techniques for preparing said synthetic absorbent gel-forming polymers are described in U.S. Pat. No. 4,076,663, Masuda et al., Issued Feb. 28, 1978; and U.S. Pat. No. 4,286,082, Tsubakimoto et al., Issued Aug. 25, 1981.

Characteristic synthetic gel-forming absorbent materials are xerogels which form hydrogels when wetted with liquid. However, the term hydrogel is commonly used for both wettable and non-wettable forms of said material.

As mentioned above, the highly absorbent material used to form the absorbent core 30 may be a gel forming the superabsorbent material, wherein the superabsorbent material may be in the form of discrete particles separated from each other. Said particles may have any desired shape configuration, such as a full or partial spiral, cubic, polyhedron, substantially rod-shaped, and the like configuration. In addition to the foregoing, it is contemplated for the purposes of the present invention that i. shape configurations that exhibit a high ratio of maximum • 0 0 0 · 0 0 9 9 9 9

9 9 9 999 9 9 9 β

0 00 00 000 00 0 0 0 0000 0000

000 0000 00 00 00 00 dimension / smallest dimension, such as needles, flakes or fibers. Optionally, conglomerates of gel-forming absorbent material may also be used to form the composite absorbent system 26. The particles usable for this purpose are particles whose average size is. ranging from about 5 microns to about 1 millimeter. As used in the present specification, the particle size is understood to mean the diameter of the smallest dimension of the individual particles.

According to specific aspects of the present invention, the gel-forming absorbent material particles may exhibit a Modified Load Absorption Absorption (MAUL) value of at least about 20 grams by absorbing the absorbed liquid per gram of absorbent material (g / g). It is desirable for the superabsorbent material to have a MAUL of at least about 24 g / g, and even more desirably for said material to have a MAUL of up to about 30 g / g or greater. The MAUL value can be determined using the test method for measuring the modified absorption absorbency under load, which is described in detail in the Calculation Methods and Test Procedures section later in the description of the present description.

The blend of hydrophilic fibers and particles of highly absorbent material in the overall configuration of the absorbent core 30 of the composite absorbent system can be configured to have an average basis weight ranging from about 400 to about 900 g / m ² . According to some aspects of the present invention, to provide the desired performance of the absorbent article, the average basis weight of the composition is in the range of about 500 to about 800 g / m ² , and preferably in the range of about 550 to about 750 g / m ² .

According to specific aspects of the present invention, the highly absorbent material may comprise a superabsorbent nonwoven material. A superabsorbent nonwoven material is a nonwoven consisting solely of a respective superabsorbent fibrous material, or a mixture of superabsorbent fibrous material and other materials. The superabsorbent nonwoven material exhibits a high liquid retention capacity when immersed in a liquid, in particular immersion in 0.9% saline, at a liquid volume capacity of at least about 10 grams by absorbing the absorbed liquid per gram of absorbent material (g / g) in order to provide improved performance characteristics, the bulk capacity of the liquid is at least about 20 g / g, and optionally at least about 30 g / g. The superabsorbent nonwoven material is selectively configured to support and enhance liquid aspiration, liquid retention, liquid distribution, or some combination thereof. In particular, in the case where the superabsorbent nonwoven material is incorporated in the absorbent article with the multilayer absorbent structure in the form of a separate layer or separate component, the superabsorbent nonwoven material may be designed to perform a specific function or group of such functions.

To reduce unwanted displacement of the highly absorbent material contained therein, the absorbent article may comprise a composite absorbent system 26 provided with an outer sheath, for example, a wrapper 28 which is conveniently positioned, as desired, in an adjacent configuration to and around the entire absorbent core 30. of the absorbent core, or around one or more selected composite components of &quot; 00 &quot; 00 &quot; 0 0 0 000 9 0 0 0 &quot;

90 «0009 0« 0 · 00 00 absorption system. In addition, said cover layer may be coupled to the composite absorbent system and various other components of the absorbent article. The wrapper 28 is preferably a layer of absorbent material that overlaps all the lateral and outer surfaces of the composite absorbent system, and preferably surrounds substantially all of the peripheral edges of the absorbent system to form substantially its entire outer skin. Alternatively, the sheath 28 may provide an absorbent sheath that covers the vast majority of the lateral and outer surfaces of the absorbent core and substantially surrounds only its lateral side edges. Accordingly, both the linear and the inwardly curved portions of the lateral side edges must be surrounded and closed around the composite absorbent system. However, in such an arrangement, the leading end edges of the wrapper may not be completely enclosed about the leading end edges of the absorbent system located in the regions of the waistband of the absorbent article.

For example, the wrapper 28 as a whole, or at least the skin-facing portion of the wrapper, may comprise a meltblown web of meltblown fibers such as polypropylene fibers. According to another example, the absorbent cover layer 28 may comprise a low void web, for example a thin paper layer consisting of a 50:50 mixture of soft / hard cellulosic fibers.

The absorbent cover layer 28 may consist of a plurality of sub-components comprising a separate body-facing cover and a separate outer garment cover layer of which

0 0000 · 0 0 0

0000 0 0 0 0 • 00 00 00 00 0 0 each extends over all or at least some peripheral edges of the absorbent core 30. Such a wrapper configuration may, for example, help to form a substantially complete closure and sealing of the peripheral edges of the absorbent core 30. At the rear waistband. For example, in the portion of the diaper shown in the accompanying drawing, the wrapper may be configured to extend over the peripheral edges of the absorbent core to increase opacity and the breaking edge strength of the diaper. In the illustrated exemplary embodiment, the inner and outer sub-layers of the absorbent cover layer 28 extend at least about 12.7 millimeters (1/2 inch) over the peripheral edges of the absorbent core to provide an outwardly extending weave by which the peripheral edges may be internal to the body. a user facing portion of the absorbent cover layer, either wholly or at least partially associated with the peripheral edges of the outer portion of the absorbent cover layer.

The inner body-facing sub-layer and the outer garment-facing sub-layer of the skin layer 28 may consist of either substantially the same or different materials. For example, the outer sublayer of the casing layer may consist of a material with a relatively lower basis weight and a relatively high voidness, such as a high wet strength thin cellulose layer formed from softened cellulose. The body-facing inner layer of the wrapper layer may further comprise one of the materials mentioned in connection with the wrapper layer, which exhibits a relatively low void space. The low void material, when used to form the inner sublayer of the packaging layer, is better able to eliminate undesirable migration. To. To. To. To. To. To. The superabsorbent material particles onto the skin of the wearer, while a material with a high void content and a lower basis weight for the outer sublayer of the cover layer can help reduce manufacturing costs. .

Referring to FIG. 7, 8 and 9, another embodiment of the absorbent core of the present invention may include a sub-element comprising particles 102 of superabsorbent material. which are operably maintained between two layers 100 of liquid-permeable material, such as paper pulp, open cell foam, porous film, woven fabric, nonwoven fabric and the like, as well as combinations thereof. According to certain specific aspects of the present invention, the backsheet 50 may consist of a laminate having particles of superabsorbent material sandwiched between two layers of retention paper pulp and enclosed by water resistant fasteners. Examples of such absorbent core configurations are described in U.S. Pat. No. 5,593,399, to R. Tanzer et al., Entitled: Absorbent article comprising superabsorbent material disposed conveniently in separate elongated pocket pouches arranged at a selected deployment, published February 14, 1997 (see Verified Annotation and Brief Content No. 10,902.1), the complete absorbent article of which the description is hereby incorporated by reference into the present invention in the sense corresponding to its nature.

Referring again to FIG. 1 and 2, the diaper 20 may further include an impact buffering layer 84 in addition to the above components to assist in retarding, mitigating, and scattering the impact waves of body fluids such that they may be

0 ·

· · ·

«0« 0

Β 0 0 0

00 0 0 «« 0 0 0 ··· 0000

0 **

0 0 0 • 0 000 directed to the retention and storage portion of the absorbent structure of the absorbent article. Said compensating layer 84 may be disposed, for example, on an inwardly facing surface of the wearer facing surface 24 of the wearer. In the exemplary embodiment of the diaper, the compensating layer 84 may be positioned adjacent the outer surface of the absorbent structure. Accordingly, the alignment layer 84 is sandwiched between the topsheet 24 and the absorbent core 30. Examples of suitable alignment layers 84 are described, for example, in U.S. patent application Ser. No. 206,986, by C. Ellis and D. Bishop, entitled: Leveling layer of nonwoven fibrous fabric, for personal protective hygiene absorbent articles and the like, filed March 4, 1994 (see Verified Annotation and Brief Contents No. 206/86).

U.S. Pat. 5,486,166; U.S. application Ser. No. 206,069, C. Ellis et al., Improved Compensation, formed from a nonwoven personal protective hygiene absorbent article and the like, filed March 4, 1994 (cf. Verified Annotation and Brief Content No. 11,387), which was published as U.S. Pat. 5,490,846; the entire description of which is hereby incorporated by reference into the present invention in the sense corresponding to its nature.

11,256), which was and in the patent Everett, on with the regulatory fabric, for

R.

layer of fiber

According to specific aspects of the present invention, and with reference to FIG. 1 and 2, the absorbent diaper 20 may comprise a composite absorbent system that includes a selected amount of two or more primary layered portions. The multilayer absorbent core 30 comprises in the configuration shown, for example, a first layer portion 48 and at least a second layer portion 50.

The first layer portion 48 of the exemplary embodiment provides, relatively relatively, an upper layer portion that is disposed on the skin facing the side of the absorbent core 30 and is relatively proximate to the top face layer 24. The illustrated second layer portion 50 provides, relatively in addition, the backsheet, which is disposed on the outer garment facing side of the absorbent core and is relatively proximate to the backsheet 22.

Upon demand in accordance with one aspect of the present invention, the individual components contained in different layer portions of the absorbent system, for example layer portions 48 and 50, may comprise a blend or other matrix of high bulk fibrous materials. High bulk fibrous materials are those that provide improved bulk stability and / or deformation recovery (restoration). Such high bulk fibrous materials are particularly capable of providing good wet bulk stability and / or wet deformation recovery when incorporated into materials that are subjected to wetting or liquid treatment. Examples of suitable high bulk fibrous materials include synthetic thermoplastic fibrous materials, synthetic materials consisting of natural polymers such as pulp, and natural fibrous materials, as well as combinations thereof. The resistance of materials consisting of natural polymers can be increased by means of chemical fiber, it is possible to crosslink and / or twist the fiber materials into loops and / or crimping

of these materials.

High bulk fibrous materials have the ability to exhibit low density in both wet and dry conditions, thereby increasing permeability and thickness, resulting in increased flow conductivity. High-volume wood pulp fiber materials can be obtained by various processing techniques, for example by chemical and / or mechanical modification of the pulp. Examples of suitable high-bulk materials suitable for use herein include mercerized fibrous materials, crosslinked technical pulp in the form of fibrous fluff, and the like, as well as combinations thereof.

According to a further aspect of the present invention, the individual components contained in the different layer portions of the absorbent system, for example the layer portions 48 and / or 50, may be a matrix of high-volume controlled fraction

Such a superabsorbent consisting of a blend or other fibrous material, and a superabsorbent material, a controlled content material in the structure, is a material, for example, a superabsorbent polymer material that exhibits a minimum modified absorbency absorption under load (MA.UL) of at least about 20 g / g.

According to another aspect of the present invention, the controlled content superabsorbent material may exhibit a specific uptake rate (time characteristic), expressed as a Tau (τ) value, for example, wherein said Tau (τ) value is at least about 0.4 min. The superabsorbent material used is required to have a Tau of at least about 1 minute, wherein:

0 0 0 ··· ···· ^β · 0 ···· ···· • * 00 00 0> · · φ • · 0 0 · · · · · · · · ······ 49 ₉₉ 44 this Tau value may be at least about 2 minutes to provide improved performance. According to other requirements of the present invention, the size of said Tau may be up to about 40 minutes or more. According to further aspects of the present invention, a selected combination of superabsorbent materials, in which at least one selected pair of different superabsorbent materials is configured to provide a ratio of Tau values of these materials, may preferably be incorporated in the absorbent core, particularly in the various layer portions of the absorbent core. is equal to or greater than about 2: 1. Optionally, in order to provide further functional improvement, said ratio of Tau values may be up to about 5: 1, or greater. Desirably, the superabsorbent material exhibiting a relatively higher Tau value is positioned relatively closer to the skin of the wearer facing the surface of the absorbent core. A suitable test procedure for determining the Tau value of each absorbent structure of the absorbent material used is described in detail in the Zero Load Inundation Absorption Absorption (FAUZL) section of the Calculation Methods and Test Procedures section.

The specific superabsorbent material having a controlled content of the structure useful for this purpose may be a particulate superabsorbent material whose individual particles are impregnated with a hydrophobic coating to provide a predetermined delay in the absorption of water-based liquids into the particle volume. Thus, the superabsorbent material used may be, for example, a particulate superabsorbent material with surface-coated particles. These particles have an absorbent core formed by a partial sodium salt of cross-linked polypropionic acid (prepared using the process described in US Patent 5,629,377) and the core is provided with a coating of a hydrophobic silicone elastomer. A characteristic superabsorbent material with controlled content in a structure of this type is commercially available from the Dow Chemical Company, with sales offices in Midland, Michigan, U.S.A.

Alternatively, the controlled content superabsorbent material in the structure may be formed with a relatively large particle size, indicating that such particles exhibit a low surface area to volume ratio and, as a result, achieve the desired rate of absorption. Further, the particles of superabsorbent material having a controlled proportion of content in the structure may exhibit a substantially spherical or other three-dimensional configuration that effectively provides a desired low surface area to volume ratio and a desired delay rate.

In addition, in addition to the above, it is possible to modify the quantitative chemical composition of the superabsorbent polymeric material in order to achieve the desired delay time. Thus, for example, an anionic polyelectrolyte, which is reversibly crosslinked with a polyvalent metal cation, may be incorporated into the controlled content content of the structure. A water-soluble complexing agent can be used to restore the crosslinking to its original state.

In an alternative embodiment, the controlled content superabsorbent material in the structure may be encapsulated in a sheathing or provided with another surface treatment to provide effective securing.

slow diffusion of the liquid into the superabsorbent material particles, or repelling the liquid so as to achieve the desired rate of absorption with delay. Said sheathing or surface treatment may be either elastically or non-elastically, and further may be either hydrophobic or hydrophilic. The described coatings may be designed as controlled erodible, dissolvable, or disintegrable by failure to achieve the desired absorbency characteristics. Optionally, the uptake rate may be limited and / or controlled by modifying the rate of neutralization of the selected superabsorbent material, or by modifying or otherwise controlling the chemical mechanism applied to effect neutralization of the selected superabsorbent material.

Other aspects relating to determining the absorption of superabsorbent material under load (AUL) are described in detail in U.S. Pat. 5,550,189, entitled Modified Polysaccharides with Enhanced Absorbent Properties, and a Process for their Preparation by J. Qin et al., Issued Aug. 26, 1996; and U.S. patent application Ser. 621,390, entitled Absorbent Composite Material, by M. Melius et al., Filed March 25, 1996 (see Verified Annotation and Brief Content No. 10,838.2). A complete description of the above-mentioned documents is hereby incorporated by reference into the present invention in the sense of its nature.

Referring to FIG. Figures 2 and 2A illustrate an exemplary embodiment of a first layer portion 48, which may include a superabsorbent material with controlled content in the structure, and high bulk fibrous wood pulp or other woven or nonwoven fibrous materials having a pore size distribution (voidability) that rapidly absorbing the acting liquid while maintaining the liquid in the volume of the absorbent material until the liquid is able to absorb relatively outwardly, the garment-facing layer or layers of the absorbent structure. The respective components in the first layer portion 48 may be arranged to substantially overlap the predetermined receiving zone 52 of the absorbent article, i.e. the zone in which the acting liquids, such as urine or other body fluids, are introduced into the absorbent structure. Accordingly, the first layer portion 48 may in fact be a defined absorbent core portion of the absorbent core. The layer portion 48 may have a rectangular, rectangular, or any other irregular shape configuration, but it is desirable that the layer portion does not exceed the layer portion below the layer portion, for example, the second layer portion 50, according to the desired aspects. According to the invention, the first layer portion will be smaller than below, relatively second outwardly relative to the arrangement of the absorbent structure, the second layer portion will be arranged.

For example, the first primary layer portion may substantially extend as a whole in a zone that begins at a transverse direction extending approximately 7% of the length of the absorbent core inwardly from its foremost edge and that ends at a transverse direction a stretch line extending approximately 52% of the length of the absorbent core inwardly from its foremost edge. In addition, the longitudinally extending side edges of the first primary layer portion may substantially border on corresponding side edges of the second primary layer portion.

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this this · this · this · 4 · ·

Further configurations of an alternative arrangement of the absorbent structure are shown in FIG. 3-6. According to particular specific aspects of the present invention, the layer portion 48 may comprise a composite absorbent system comprising a plurality of partial layer portions.

Giant. 3 and 3A illustrate, for example, the structure of the absorbent core, seen from above, provided with a first topsheet 48 extending over a central region of the total extent of the absorbent core 30 and a second bottomsheet 50 extending over substantially the entire overall range of this absorbent core. The second layer portion 50 exhibits a selectively distributed, uneven zonal basis weight with a relatively higher basis weight at its longitudinally opposed end portions, resulting in an inverse zonal distribution of the lower layer portion in the longitudinal direction, particularly in its receiving zone. In addition, the determined central zone of the second layer portion 50 may have a basis weight that is less than the base weight adjacent thereto and overlapping the first layer portion 48, thereby providing a reverse zonal thickness in the acquisition zone. The lateral end edges of the topsheet 48 in the transverse direction, at least in the crotch region of the absorbent core 30, border with corresponding lateral end edges of the secondsheet 50. The front end edges of the firstsheet 48 extend longitudinally relative to the corresponding end edges of the secondsheet. 50 offset inwards.

Giant. 4 and 4A illustrate, for example, the structure of the absorbent core provided with a first topsheet 48 that covers the entire extent of the front and first sections, respectively, with the second, bottomsheet 50, and only a portion of the back and second sections of the backsheet, respectively. The lateral end edges in the transverse direction and at least a portion of the front end edges in the longitudinal direction of the first layer portion 48 substantially abut the corresponding lateral end edges in the transverse direction and at least a portion of the front end edges in the longitudinal direction of the second layer portion 50. one end face of the first layer portion 48 in the longitudinal direction is disposed inwardly relative to the corresponding end face of the second layer portion 50.

Giant. 5 and 5A illustrate, for example, an absorbent core structure having a first topsheet 48 and a second bottomsheet 50 that are arranged such that the topsheet 48 overlaps the bottomsheet 50 in its entirety. Although, in the embodiment shown, the first topsheet 48 and the second, bottomsheet 50 have substantially the same thickness and basis weight, in an alternative embodiment, the firstsheet 48 and the secondsheet 50 may also have a different thickness and different base weight. weight as well as other structural differences.

Giant. 6 illustrates, from a top view, another absorbent core arrangement whose first topsheet 48 has a smaller, narrower dimension in both the transverse direction and a smaller shorter dimension in the longitudinal section compared to the dimensions of the second, lowersheet 50. direction. In the embodiment shown, the outer periphery of the end edges of the first layer is fefefe

5b of the portion 48, substantially whole, spaced apart from the entire outer periphery of the end edges of the second layer portion 50 inwardly.

In various embodiments of the present invention, superabsorbent material can be configured to control the rate and / or intensity of liquid retention in the various layer portions of the absorbent system with controlled content of the structure. The absorbent structure can provide controlled control of the liquid retention rate in volume only by the presence of a controlled content superabsorbent material (SAM), or by combining the superabsorbent material with other materials to provide a superabsorbent composite material with the controlled content of the structure. The superabsorbent material or the controlled content superabsorbent composite material may be used as the absorbent layer portion in the layered portions of the layered composite absorbent system, especially when the structure controlled superabsorbent material (SAM), the controlled content superabsorbent composite. in the structure, it is selectively configured to promote preferential saturation of one or more additional layered portions in the multilayer absorbent system during appropriate functional use conditions. By using a combination of high bulk fibrous materials and a superabsorbent material with a controlled amount of content in the structure, the saturation in the first layer portion 48 can be maintained at a value less than the saturation level in the other absorbent layer portions resulting from the fact that the first layer portion 48 exhibits a higher void volume and throughput in this state, and provides

4 4 4 4 · 4 4 4 4 4 4 4 444 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

444 4444 44 44 44 44 required levels of flow conductivity.

A composite material consisting of a high-volume fibrous material, in particular fibrous pulp, and a superabsorbent material can also be modified by introducing a stabilizing agent into the material. Said stabilization is used to maintain or minimize the occurrence of changes in the structure of the particulate material or in the composite structure of the materials during their exposure to external or internal forces. The structure of the stabilizing mechanism may be useful for any layered portion arranged in a layered layered portion comprising the structure by assisting in maintaining the layered portion containing the absorbent structures in the desired state during exposure to forces applied to the structure under functional application conditions as part of an absorbent article comprising a multilayer absorbent core. . This helps to maintain and perform the intended functional operation of the layer portion, namely, sucking in the liquid (void volume formation), retaining the liquid, distributing the liquid, or some combination of these three functions. For the purpose of stabilizing the absorbent structure, it is possible to use various types of suitable and suitable technological processes. Corresponding stabilization can be performed, for example, by chemical stabilization using stabilizing agents, for example Kymene or other crosslinking agents, or by introducing thermoplastic binder fiber materials or the like.

According to various aspects of the present invention, the topsheet portion 48 may consist of the woven or nonwoven prior to these fibrous material materials. As with aspects of the present invention, they can be configured to provide maximum void volume and permeability while maintaining sufficient capillary stress to ensure controlled fluid displacement and complete elimination of unwanted leakage. For example, nonwoven fibrous materials may be incorporated into the absorbent cores of the present invention as functional components of the topsheet 48. A specific example of such fibrous materials is carded bonded webs or webs, which may be configured to provide sufficiently adequate permeability and capillary capillarity. By selecting specific properties of the staple synthetic staple, it is possible to form a composite structure in which the lower layer portion 50 is preferably saturated. This effect can be achieved either by physically structuring the upper layer portion, controlled by surface chemistry, or a combination thereof. The voidiness of the fiber structures can be determined by specific fiber materials or by pre-selected fiber sizes. The capillary capability of the fibrous material can also be influenced by the choice of the structure of the fibrous material.

Suitable carded structures for this purpose are formed from different types of fibrous materials and a variety of fiber sizes. These fibers may be fibers made of synthetic or naturally occurring materials. It is desirable that the fibrous materials intended to form the first layer portion 48 exhibit high wettability and natural pulp materials such as silk may be used for this purpose.

0 • ··· or cotton. Synthetic fibrous materials such as polyester and polyamide provide limited wettability, but this can be increased by hydrophilic surface treatment or finishing. Although fibers with diameters ranging in a relatively wide range are present in carded nonwoven webs, the desired structure should include fibers with an equivalent diameter of less than 25 microns. The carded bonded fibrous materials intended to form the first layer portion 48 may be manufactured with a basis weight ranging from 50 to 200 grams per square meter (g / cm ² ) and a density of about 0.03 g / cm ² or less. The density of the fibrous material will in fact depend on the bonding or stabilization procedures used to process it into a web or web.

The carded webs can be stabilized behind. use of various technological processes. In some instances, the incorporation of a thermoplastic staple synthetic staple is used such that the formed structure can be bound by applying heat and pressure. By suitable application of heat and pressure in the thermal bonding, the resulting structure can be obtained, is adequately stabilized and exhibits a precisely determined permeability and capillary capillarity. Further, structures formed from carded bonded fibrous materials can be stabilized by the use of synthetic resins or binder adhesives. Again, as in the above uses, the choice of the type of synthetic resin or binder adhesive, the amount added and the method of curing thereof will facilitate the control of the final properties of the fibrous structure, which provide adequate permeability and capillary capillarity.

- 60 - * ♦ 0 0 0 0 · · · · 0 0 000 0 φ 0 0 • 00 00 000 00 0 0 0009 0090

9900 00 90 90

Wettability can be influenced by the appropriate choice of the synthetic resin system for bonding. In addition, structures formed from carded bonded fibrous materials can be stabilized mechanically using water, needling fibers, air or other fiber splicing means. Again, these technological processes can be controlled in a manner that ensures the desired physical properties of the material.

According to specific aspects of the present invention, a spunbonded web or web having similar properties to the materials described above may be incorporated into the absorbent structure. In other aspects, said material may also include a selected fiber size zone distribution, basis weight, or other characteristics required to provide the desired functional properties. In addition to carding spunbonded and spunbonded fibrous webs and webs, fibrous materials deposited by air may also be used for this purpose.

The individual constituents of the materials contained in the first layer portion 48 may be present in an amount, basis weight, density, and the like, as described below. The characteristic basis weights of the absorbent core region located in the front half of the absorbent article can range from about 750 to about 750.

905 g / cm ³ . The first layer portion 48 can provide approximately 25 to 75% of the total basis weight of the composite system in those regions in which the layer portion is present. This proportion is highly dependent on the materials used and their relative functional capabilities and efficacy. Materials in which · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Are superabsorbent materials used in combination with fluff pulp and / or some staple synthetic staple fibers, will typically exhibit an initial density in the range of about 0.1 to about 0.3 g / cm ³ . Synthetic base materials, carded bonded and spunbonded webs or webs will typically have a density ranging from about 0.015 to about 0.3 g / cm ³ , with a density of from about 0.015 to about 0.3 g / cm ³ .

0.2 g / cm ³ . Fabrics made of synthetic fibers will exhibit a characteristic fiber size (yarn fineness) of less than 3 denier, preferably a fiber size ranging from 1 to 2 denier, and will be treated to have a low wetting angle with water even after multiple wetting. Desirably, said treatment does not reduce the surface tension of the liquid passing through the fibrous sheet.

In addition, other nonwoven fibrous materials and structures may be used to form the topsheet portion of the absorbent system of the present invention. A suitable balance of the absorbency and capillary capillarity of the lower layer may ensure a preferential saturation of the lower layer even after multiple impact of the liquid. It is also foreseeable to use a different backsheet that exhibits improved distribution capabilities. Said abilities may assist in the desorption of the topsheet of the nonwoven fabric, which may result in improved performance of the absorbent system after the second impact of the liquid.

According to desired aspects of the present invention, the absorbent structure may have a liquid wicking value that is greater than about 36%. According to other aspects of the present invention, it may have an absorbency value greater than about 16%, and a flow conductivity value greater than about 7.10 ^-6 cm ^-3 . According to still further aspects of the present invention, it may exhibit a combined conductivity / absorbency value (C) of at least 14.10 ^-6 cm ³ .

The desired combination of flow conductivity and liquid wicking properties can provide an advantageous balance of controlled liquid control characteristics. In particular, said combination may provide the desired balance of rapid fluid intake together with rapid displacement of absorbed liquid from the intake receiving zone towards more distal regions of the absorbent system. The commonly used absorbent systems are unable to provide the desired combination of properties. Especially since absorbent systems that provide the desired rapid fluid intake are unable to provide sufficient velocity-sufficient displacement of absorbed liquid from the intake receiving zone towards their more distal regions, and absorbent systems that exhibit rapid displacement capability. the fluids from the suction receiving zone towards their more distal regions are not capable of providing a sufficiently rapid suction of liquid. This may result in premature, excessive saturation of the absorption zone of the absorbent system, or undesirable excess accumulation of liquid on the surface of the absorbent article against the skin of the wearer.

According to specific aspects of the present invention, 9,999 may be used

9999

9 '9

9 9 9

99

9 9 «* 9 9 9 • 0 0 1

0 0 0

The first layer portion 48 may be an upper skin-facing layer which may typically extend across the central zone of the total absorbent core range, but may optionally extend across the entire absorbent core range, if desired. Typically, the topsheet is a layer that is optimized for performing suction and may or may not provide the desired performance levels of water absorption and liquid distribution. The first layer portion may typically have a minimum basis weight of not less than about 100 g / cm 2, and preferably may have a basis weight of not less than about 300 g / cm 2. According to further aspects of the present invention, the first layer portion may have a maximum basis weight not greater than about 700 g / cm 2, and preferably may have a basis weight not greater than about 600 g / cm 2.

Referring to FIG. 3 and 3A, the first layer portion 48 typically comprises a minimum amount of fibrous material that is not less than about 50% by weight, and preferably includes an amount of fibrous material that is not less than about 60% by weight. According to further aspects of the present invention, the first layer portion may typically comprise a maximum amount of fibrous material not greater than about 80% by weight, and preferably may comprise an amount of fibrous material not greater than about 70% by weight. The fibrous material may be a natural or synthetic material. Said fibrous material may have a minimum fiber size, in particular a fiber diameter, of at least about 4 microns (pm), and preferably has a fiber size of at least about 10 microns. According to other aspects of the present invention, the fibrous material may have a maximum fiber size of no greater than about 9999 microns (pm), and preferably has a fiber size of no greater than about 15 microns.

The first layer portion 48 may further comprise a minimum amount of superabsorbent material that is not less than about 20% by weight, and preferably may comprise an amount of superabsorbent material that is not less than about 30% by weight. According to further aspects of the present invention, the first layer portion may comprise a maximum amount of superabsorbent material that is not greater than about 50% by weight, and preferably may comprise an amount of superabsorbent material that is not greater than about 40% by weight. Said superabsorbent material may have a minimum dry particle size of not less than about 110 microns, preferably having a dry particle size of not less than about 300 microns. According to other aspects of the present invention, the superabsorbent material may have a maximum dry particle size not greater than about 1000 microns, and preferably may have a dry particle size not greater than about 700 microns. The superabsorbent material may further have a MAUL of at least about 20 g / g, and preferably may have a MAUL of at least about 25 g / g. In addition, in addition to providing improved material utilization, the MAUL may be up to about 30 g / g or greater. In yet other aspects of the present invention, the superabsorbent material may have a minimum Tau of at least about 0.8 min, and a maximum Tau of up to about 40 min.

The first layer portion 48 may typically exhibit a minimum average density of at least about

0.03 g / cm ³ , preferably having an average density of &quot; * &quot;

0 0 0 0 0 0

0 0 · 00 «

0 0 «« «« ««

At least about 0.05 g / cm ² . According to further aspects of the present invention, the first layer portion may have a maximum average density not greater than about 0.4 g / cm ² , and preferably may have an average density not greater than about 0.2 g / cm ² . The first layer portion includes any paper layers that are. used for the purpose of retaining the materials placed in the first layer portion or acting as carrier means. For example, some of these paper layers may be used to maintain sandwiched superabsorbent material between these layers.

Various embodiments of the present invention may include any highly effective absorbent material in selected layers of the absorbent structure. Examples of suitable and suitable suction materials may include those described in detail in U.S. patent application Ser. No. 754,414 entitled Multi-Purpose Absorbent Material and articles made of this material by R. Anderson et al., Filed Nov. 22, 1996 ( see verified annotation and brief content No. 12,442); and in U.S. Patent Application Serial No. 068,534 entitled Pulp and Superabsorbent Composite for Improving Suction Efficiency by LH Sawyer et al., filed December 23, 1997 (see Verified Annotation and Brief Content No. 13,041). Full descriptions of the aforementioned documents are hereby incorporated by reference into the present invention in a sense consistent with its spirit. ^WITH

Referring to FIG. 3 and 3A may be second. the layer portion 50 comprising a blend or matrix of a hydrophilic fibrous material, such as wood pulp in fibrous form, and a selected amount of gel-forming superabsorbent material, such that the second layer portion comprises feosa Coosa 1654 wood pulp and superabsorbent type Stockhausen Favor 880. These materials will be conventionally mixed or otherwise combined such that about 20 to 80 wt. of the composite structure formed are superabsorbent material particles. In order to provide increased efficacy, the material may be modified accordingly. Such process modifications may include the use of fashioned pulp fibers to achieve improved liquid distribution efficiency, or the use of a stabilization technology to provide structure reinforcement and improved liquid wicking performance. Possible considerations for stabilization methods that may be used include, but are not limited to, the use of a binder material, such as a Kymene material, or some other crosslinking agents, or the introduction of a heat-activatable binder fiber into the stabilized structure. materials. Structure stabilization is a technological process that is used to solidify, maintain, or minimize the occurrence of changes in the structure of a material or in the structure of a composite blend of materials while subjected to external or internal forces. Various techniques may be used to effect stabilization of the structure, such as the introduction of thermoplastic binder fiber materials, chemical stabilization using stabilizing agents (e.g., Kymene-type reagent) or other crosslinking agents, and the like, as well as combinations thereof.

can

Desired functional capabilities and efficiency to provide any material of choice •

Functionally configured to exhibit the ability to provide improved distribution of the acting liquid from the acquisition zone. Such materials may consist of a layered material comprising particles of superabsorbent material and at least one fibrous sheet or web configured in particular to exhibit improved inundation water absorption efficiency upon impact of the applied liquid. Suitable arrangements of the second layer portion 50 may include, but are not limited to, optional laminate materials consisting of particulate or fibrous superabsorbent sheets or webs of pulp based fibrous materials, or any other stabilized fibrous web. Other suitable fibrous materials may include wet-spun paper pulp, air-blown fibrous materials, as well as the types of fibrous materials used to form the first sheet portion 48. Other types of materials that are useful to provide the desired improved performance are laminated materials of superabsorbent or superabsorbent sheet fabrics and a wettable open cell foam.

consisting of fibrous

The second layer portion 50 may be disposed within the absorbent structure in a variety of suitable and convenient configurations. For example, the second layer portion 50 may be in the form of a separate absorbent pad, which is expediently positioned in an immediately adjacent configuration to the first layer portion 8. The second layer portion 50 is preferably arranged in substantially direct contact with the first layer portion 48; alternatively, however, the second layer portion 50 may be spaced from the first layer portion 48 by means of one or more 4 layers of selected material sandwiched between said first and second layer portions 48 and 50. According to specific aspects of the present invention, In the present invention, the second layer portion 50 is configured to provide and allow maximum utilization of the absorbent material to process the incoming liquid while maintaining the comfort properties of the absorbent article.

According to further aspects of the present invention, the second primary ply may have a longitudinal extent that is greater than the longitudinal extent of said first primary ply. In addition, in addition, the second primary ply may have a transverse extent that substantially coincides with the transverse extent of said first primary ply. Alternative embodiments of the present invention may include a second primary layer portion having a transverse range that is less than the transverse range of said first primary layer portion. In this state, for example, the transverse extent of at least a portion of the second primary layer portion may not be less than about 30% of the transverse extent corresponding to that portion of the second primary layer portion of the adjacent portion of the first primary layer portion. Other embodiments may include a second such primary layer portion that has a transverse range greater than the transverse range of the first primary layer portion. In this state, for example, the transverse extent of at least a portion of the first primary layer portion may not be less than about 30% of the transverse extent corresponding to that portion of the first primary layer portion of the adjacent portion of the second primary layer portion.

Referring to FIG. 3 and 3A, the individual constituents of the materials contained in the second primary layer portion 50 may be the same.

present in different effective amounts, different basis weights, different densities, and the like. For example, the second primary layer portion 50 may have a selected unevenly distributed basis weight. In addition, the second layer portion may consist of about 25 to 100% of the total basis weight of the composite structure of the absorbent core at any selected position, typically having a density ranging from about 0.1 to about 0.3 g / cm ³ . According to still further aspects of the present invention, the second layer portion may have a plurality, two or more, of the partial layer portions, each of said partial layer portions having a selected combination of physical and functional characteristics.

According to specific aspects of the present invention, at least one of said layer portions of the absorbent core 30 is a liquid distribution layer capable of providing a liquid wicking value of not less than about 16%. In addition, the distribution layer has a circumferential boundary and a surface area extending over and outside the designated receiving zone 52 of the composite absorbent system.

Said distribution layer may advantageously provide certain specifically important functions. The first function comprises retention retention and displacement of the acting fluid from and outside the receiving zone, and the second function is to provide a sufficiently short (over the duration of the impact) duration of the inundation absorbency of the superabsorbent structure causing the void volume deficit associated with absorbent articles in small thicknesses. The structural components of this layer portion include the content of the superabsorbent polymer material (SAP), the basis weights of the individual components, and their density. Examples of high efficiency liquid wicking materials are described in detail in U.S. Pat. No. 5,350,370, entitled Absorbent Composite Materials with High Liquid Absorption, by D.M. Jackson et al., Issued Sep. 27, 1995, the entire disclosure of which is hereby incorporated by reference in its entirety.

The second layer portion 50 may provide a backsheet, and typically may extend over the total surface area of the absorbent core 30 as a whole. This second layer portion 50 is typically designed to provide liquid distribution or absorbability in the absorbent core volume and, therefore, will typically extend over and beyond the end peripheral edges of the sheet area overlapped by the first layer portion 48. In the acquisition zone section 52, the second layer portion 50 may typically have a basis weight of not less than about 100 g / m ² , and preferably may have a basis weight of not less than about 200 g / m ² . According to further aspects of the present invention, the acquisition zone of the second layer portion 50 may have a basis weight not greater than about 700 g / m ² , and preferably may have a basis weight not greater than about 250 g / m ² . In other, non-receiving regions located outside and outside the receiving zone of the second layer portion 50, the second layer portion may typically have a basis weight of not less than about 300 g / m ² , and preferably may have a basis weight of not less than about

450 g / m ² . According to further aspects of the present invention, the other, non-receiving portions located outside and outside the receiving zone may typically have a basis weight of not more than about 800 g / m ² , preferably having a basis weight of less than about 800 g / m ² . a mass not greater than about 550 g / m ² .

The second layer portion typically comprises an amount of fibrous material that is not less than about 50% by weight, and preferably includes an amount of fibrous material that is not less than about 60% by weight. According to further aspects of the present invention, the second layer portion may typically comprise an amount of fibrous material that is not greater than about 95% by weight, and preferably may comprise an amount of fibrous material that is not greater than about 80% by weight. The fibrous material may be both natural and synthetic. Said fibrous material may have a minimum fiber size, in particular a fiber diameter, of at least about 4 microns (pm), preferably having a fiber size of at least about 10 microns. According to other aspects of the present invention, the fibrous material may have a maximum fiber size not greater than about 20 microns, and preferably has a fiber size not greater than about 15 microns. In addition, said fibrous material may have a water wetting angle of no more than about 70 degrees, and preferably may have a water wetting angle of no more than about 50 degrees.

The second layer portion may further comprise an amount of superabsorbent material that is not less than about 5% by weight, and preferably it may contain an amount of superabsorbent material that is not less than about 15% by weight. According to further aspects of the present invention, the first layer portion may comprise an amount of superabsorbent

0 ·

Preferably, the material may comprise an amount of superabsorbent material of not more than about 40% by weight. Said superabsorbent material may have a minimum dry particle size of not less than about 110 microns, preferably having a dry particle size of not less than about 300 microns. According to other aspects of the present invention, the superabsorbent material may have a maximum dry particle size not greater than about 1000 microns, and preferably may have a dry particle size not greater than about 700 microns. The superabsorbent material may further have a MAUL of not less than about 20 g / g, and preferably may have a MAUL of not less than 25 g / g. In addition, in addition to providing improved material utilization, the MAUL may be up to about 30 g / g or greater. According to still other aspects of the present invention, the superabsorbent material may have a Tau value of at least about 0.8 min, and preferably may have a Tau value of at least about 2 min.

Preferred embodiments of the present invention may include a second layer portion 50 having a liquid wicking value of at least about 36% and comprising a superabsorbent material having a Tau value of not less than about 0.4 min. Other preferred embodiments may include a second layer portion having a liquid wicking value of at least about 16% and comprising a superabsorbent material having a Tau value of not less than about 0.67 minutes.

According to specific aspects of the present invention, the superabsorbent material is comprised in a first sheet material

A portion of £ 8 configured to exhibit a Tau value that is twice the Tau value of the superabsorbent material contained in the second layer. 50 (ratio of Tau values is approximately 2: 1). Alternatively, to provide the desired characteristics, said ratio of Tau values may be at least about 2.5: 1, and optionally at least about 3: 1. According to further aspects of the present invention, the combination of superabsorbent materials comprised in the first and second layers may be configured to provide a Tau ratio of up to about 10: 1, alternatively, the combination may be configured to have a Tau ratio of up to about 10: 1. 40: 1 or more.

Typically, the second layer portion 50 may have a minimum average density of at least about 0.01 g / cm ³ , preferably having an average density of at least about 0.15 g / cm ³ . According to further aspects of the present invention, the second layer portion may have an average density of not more than about 0.3 g / cm ³ , and preferably may have an average density of no more than about 0.25 g / cm ³ . According to specific aspects of the present invention, the average density may be about 0.2 g / cm ³ . The second layer portion comprises any selectable paper layers that are used to hold materials placed in the first layer portion together or act as carrier means. For example, some of these paper layers may be used to maintain sandwiched superabsorbent material between these layers.

Further detailed descriptions of various embodiments of the layered absorbent structure of the present invention are set forth in U.S. Pat. 09 / 096,652, by title Layered • · • · · 4 * 4 4 • 4 4 4 4 · 4

4 4 4 • 4 4 4 4 4 4 4 <4 4 4 4 4 4 * 4 4 absorption structure by R. Everett et al kol., filed 12. June 1998 (see verified annotation and brief content No. 13,505); in patent U.S. application Ser. 09 / 096,653, o title Layered

an absorbent structure with a heterogeneous layered portion by R. Everett et al., filed June 12, 1998 (see Verified Annotation and Concise Content No. 13,507); and U.S. patent application Ser. No. 09 / 097,029, entitled Layered Absorbent Structure with a Zonal Base Weight of a Heterogeneous Layer Particle, by R. Everett et al., Filed June 12, 1998 (see Verified Annotation and Brief Content No. 13,508). Full descriptions of the aforementioned documents are hereby incorporated by reference into the present invention in a sense consistent with its spirit.

Referring again to FIG. 1, it can be seen that elastic leg region elements 34 are disposed on the side end edges 110 of the diaper 20 and are arranged to contract and hold the diaper 20 on the user's legs. The leg region elastics 34 are fastened to the diaper 20 in an elastically gripping state so that they are under a certain tightening tension in the normal configuration and effectively contract against the diaper 20. The leg region elastics 34 may be secured in said elastically gripping state by at least two methods, for example by first placing said leg region elastic elements 34 in an expanded state and then securing it to the diaper 20 which is in the normal uncontracted state. . Alternatively, the diaper 20 may be retracted into a corresponding configuration, for example, by pleating or shirring, and the leg region elastics 34 are attached to the diaper in their relaxed or unstretched condition. Other means or mechanisms, such as a heat-shrinkable elastic material, may also be used to pleat or contract the absorbent article.

In the embodiment shown in FIG. 1, the leg region elastics 34 extend substantially the entire length of the diaper region intermediate portion 42. Alternatively, the leg region elastics 34 may extend over the entire length of the diaper 20 or any other length suitable to provide elastic fit. the seaming lines required for the corresponding particular outer design and shape of the diaper.

The leg region elastics 34 may have substantially any configuration. Accordingly, for example, the width of the individual elastic members 34 may vary from 0.25 to 25 millimeters (0.01 to 1.0 inches) or more. The elastic members may consist of a single strip of elastic material, a plurality of strips of elastic material arranged in parallel or otherwise, or may be applied in a straight or curved configuration. In the case of a non-parallel arrangement of the bands of elastic material, two or more bands in the elastic member may intersect or otherwise interconnect. The elastic members may be affixed to the diaper 20 by any of a number of methods known in the art. Thus, the elastic members may be affixed to the diaper 20 by means of ultrasonic, thermal and pressure bonds using various bonding gratings or adhesive bonds, sprayed or as a segment or point network of hot melt adhesive.

In specific embodiments of the present invention, the leg region elastic elements 34 include a carrier layer to which the elastically coupled elastic assembly 4 is attached.

44 4 4 • 4 4

4 4

4 «

elements comprising a plurality of individual elastic bands. The elastic bands may intersect or otherwise interconnect, or may be separated from each other. For example, the backing layer may be formed by a foil made of 0.002 cm thick untreated polypropylene material. For example, the elastic bands may consist of an elastomer with the trade name Lycra, marketed by DuPont, with a sales office in Wilmington, Delaware. Each elastic web exhibits a characteristic yarn weight fineness in the range of about 470 to about 1500 decitex, and preferably in the range of about 940 to about 1050 decitex. According to a specific embodiment of the present invention, three or four elastic leg bands may be used for each elasticized waistband region of the wearer's leg.

In addition, the leg region elastics 34 may be generally straight or optionally curved. For example, the curved elastic members may be arcuate inward towards the longitudinal axis of the diaper. In specific embodiments, the curvature of the elastic members need not be configured or arranged symmetrically about the longitudinal axis of the diaper. The curved elastic members may be arcuate inwardly and outwardly in the mirror arrangement, and the longitudinal placement of the centers of the elastic members may optionally be offset by a selected distance toward either the front or back waistband portion of the diaper to provide the desired fit of diaper on the body the user and ensure its desired appearance. According to specific embodiments of the present invention, the nearest point (or apex) of the set of curved elastic members may be offset toward the front or back waistband portion of the diaper and outwardly curved mirror arrangement

• 0 »· • 0 * • · 000 ··

The portion may be positioned towards the front waist portion.

According to an exemplary embodiment, the diaper 20 may further comprise an elastic waist region member 32 disposed conveniently at the longitudinal edges of either one, the front waist panel 38 or the back waist panel 40, or both. The elastic member 32 may consist of any suitable elastomeric material, such as an elastomeric sheet, an elastic foam, a plurality of members of a composite elastic web, elastomeric webs or the like, as well as combinations thereof. A suitable design of the elastic waist region is described, for example, in U.S. Pat. No. 4,916,005, to Lippert et al., The entire disclosure of which is hereby incorporated by reference into the present invention in its entirety.

The diaper 20 may further comprise a pair of elasticized control retention flaps 82 that extend over its entire dimension in the length direction 86. The control retention flaps are typically arranged relative to the longitudinal axis of the diaper, at their sides closer to the center away from the elastic members. 34 and substantially symmetrically to each side. In the illustrated embodiment, each control retention flap 82 has a substantially rigid edge section 81 and a substantially adjustable edge section 83, which are effectively elasticized to promote tight fit and conform to each control retention flap to the contour of the user's body. Examples of suitable designs of regulatory retaining flaps are described in U.S. Pat. 4,704,116, et al

K. Enloe, published November 3, 1987, whose full description

To toto toto to to to to ·

This is hereby incorporated by reference into the present invention in a sense appropriate to its nature. Said control retaining flaps may consist of a wettable or non-wettable material as desired. In addition, the material used to form the regulatory containment flaps may be substantially liquid-impermeable, or liquid-impermeable, and at the same time permeable to gas, or permeable to both liquid and gas. Other suitable regulatory retaining flaps arrangements are described in U.S. Pat. No. 208,816, entitled Absorbent Article with Enhanced Leveling Layer, filed on March 4, 1994 by Everett et al. (Cf. Verified Annotation and Brief Content No. 11,375), published as U.S. Pat. No. 5,562,650, the entire disclosure of which is hereby incorporated by reference into the present invention in a manner consistent with its spirit.

In optional alternative embodiments of the present invention, the diaper 20 may include such elasticized restraining flaps 82 as described in U.S. Pat. No. 4,735,646, inventor

K. Enloe, published June 28, 1988; and U.S. patent application Ser. 560,525, entitled Absorbent Article with Improved Elastic Edges and Regulatory Restraint System, by D. Laux et al., Filed Dec. 18, 1995 (see Verified Annotation and Brief Content No. 11,091), the entire disclosure of which is hereby incorporated by reference. in the sense of its nature. The belt flaps may, like the control retention flaps 82, consist of a wettable or non-wettable material. Said belt flap material may be substantially either impermeable or liquid impermeable and gas permeable, or permeable to both liquid and gas.

0

0 ·

·4 · «•« 0 ··

0 0 · «

00

0 0 0

0 0 0 • ♦ 0 0 • 0 0 0 • · · 0

For the purpose of providing a reclosable fastening system, the diaper may have a suction section 78 (see Fig. Functional receiving area for include fastening 2), which represents receiving a releasable fastening by the fastening tabs 44. In specific embodiments of the present invention, the fastening suction section is disposed on the outer surface of the backsheet 22 and conveniently disposed on the front waistband portion 38 of the diaper. The fastening mechanism between said suction section and the fastening flaps 44 may be adhesive, cohesive or mechanical means, as well as a combination thereof. In a releasable, engaging functional fastening system configuration, the first functional fastener component may be disposed on the fastening suction section 78 and the second cooperating functional fastener component disposed on the fastening tab 44. For example, when using a hook and loop fastening system, the hook material portion 46 effectively coupled to the fastening tab 44 and the eyelet material portion 80 may be attached to the fastening suction section 78. Alternatively, the eyelet material may be operatively coupled to the fastening tab 44 and the hook material portion 46 may be fastened to the fastening suction section 78 .

In various embodiments of the present invention, the fastening tab 44 may be conveniently located either on the side end region 116, the side end region 118, or on both said regions, either the front waist panel 38, the back waist panel 40, or both. In addition, the backsheet 22 may be provided on its outer surface with a designated fastening suction section 78.

• fe • fefe * fefe * fefe • fefe • fe fe ♦ * fefe

Referring to FIG. 1, the diaper may comprise, for example, a side panel system 90. In specific arrangements, each of the side panels 90 extends transversely from mutually opposed side ends of at least one waistband panel portion 22, such as the backband panel 40 shown, for example. to provide the formation of side end portions of the absorbent article. In addition, each of the side panels 90 may span the space present. substantially between the transversely extending waist end edge 106 and the diaper region; which are formed by foot holes. For example, the diaper 20 has a pair of leg openings opposed to one another formed by respective intermediate sections of the illustrated pair of longitudinally extending side end edges 110 (see Figure 1). Each panel may span a longitudinal distance of at least about 4 cm, optionally span a longitudinal distance of at least about 5 cm, and alternatively span a distance of at least about 6 cm, to provide an improved efficient fit.

In various embodiments of the present invention, the side panels 90 may be formed integral with the selected diaper component. For example, the side panels 90 may be formed integrally with the material layer of the backsheet 22, or may be formed integrally with the material forming the topsheet 24. In alternative embodiments of the present invention, the side panels 90 may consist of one or a plurality of separate, spaced apart elements which are connected to either the backsheet 22 or the topsheet 24 that are attached between said

0 ·

0 ···

0

000 • · 0

0 · ·· «♦ 0 0

Layers or layouts.

which include combinations thereof

According to specific aspects of the present invention, each of said side panels 90 may be formed as a separate member, which is then assembled and attached accordingly to the selected front and / or rear waistband portion of the diaper. In the illustrated exemplary embodiments of the present invention, each side panel 90, through its attachment zone 94, is coupled to the backsheet of the backsheet 22, and may be functionally coupled to either the topsheet, the backsheet, or both. In the illustrated embodiment, each side panel has an internally arranged attachment zone that is folded over its corresponding region of the lateral end edge of the respective waist panel and laminated thereto. The side panels 90 extend transversely to form a pair of opposing band fastening tabs, and are fastened to the diaper by suitable fasteners, such as adhesive, thermal or ultrasonic bonds, snap fasteners, snap fasteners, or the like. Preferably, the side panels extend transversely over and beyond the end side edges of the backsheet and the topsheet and are secured in the waistband section of the absorbent article.

The side panels 90 may consist of a substantially non-elastomeric material, such as a polymeric film, a woven fabric, a nonwoven fabric, and the like, as well as combinations thereof. According to specific aspects of the present invention, the side panels 90 consist of a substantially elastomeric material such as 0 0 · 0.000 <0 0 · 0 · 0 · 0 00

Extensible bonded laminate (SBL), neck bonded laminate (NBL), elastomeric sheet, elastomeric foam, or the like, which is elastically extensible in at least the longitudinally extending longitudinal direction 86. Corresponding Elastomeric fibrous sheet webs for forming side panels 90 are meltblown and blown, for example, as described in U.S. Pat. No. 4,663,220, issued May 5, 1987 to T. Wisneski et al., The entire disclosure of which is hereby incorporated by reference. Examples of composite fabrics consisting of at least one non-woven textile layer bonded to a fibrous elastic layer are detailed in EP 0 217 032 A2, J. Taylor et al., Published April 8, 1987, the entire disclosure of which is hereby incorporated by reference. of the present invention. Examples of NBL materials are described in detail in U.S. Pat. No. 5,226,992, Mormon, issued Jul. 13, 1993, the entire disclosure of which is hereby incorporated by reference.

As mentioned above, various for the applicable designs may be used to attach the side panels 90 to selected regions of the waistband portions of the absorbent article. Specific examples of securing a pair of elastically extensible side panels to respective side portions of the absorbent article so as to extend transversely beyond the corresponding side portions of the outer protective layer or the like of the absorbent article may be found in U.S. Pat. No. 4,938,753, inventor

P. VanGompel et al., Issued Jul. 3, 1990, the entire disclosure of which is hereby incorporated by reference into the present invention in the sense of the present invention.

·· • 0 • · • «0

0 »• 0 * · 0 0 · • 00 ···· · · 00 • 0 0

0 000 • 0 0 Φ • 0 0 0

00

0 · 0 0

0 0

0 0

In cases where the side panels 90 consist of an elasticized or otherwise treated material so as to exhibit elastic extensibility, such elasticized side panels may, upon request and upon exposure to a specimen of such material, be subjected to a tensile stress load of 0.33 lbs. per linear inch in the direction of the test piece, measured perpendicular to the direction of application of the applied load (about 0.58 Newton / cm), provide an elongation of at least 30 percent at peak load. Alternatively, the elastomeric side panel 90 may provide an elongation of at least 100%, and optionally an elongation of at least 300%, to provide the desired improved effect.

Each of the side panels 90 extends laterally in a transverse direction from mutually opposed side end portions of at least one of said waistband portions 20. In an exemplary embodiment, each side panel extends laterally in a transverse direction from mutually opposite end portions of a back waist portion of Each of said side panels includes a relatively outwardly extending free end section 92 having a predetermined longitudinally extending length dimension. In addition, each of the panels has a transversely extending width dimension and a fastening zone 94 having a laminated binding means by which each of the panels is attached to the top face layer and / or the backsheet. The side panels may have a tapered or any other contour configuration in which the base length of the side panel attachment zone 94 is greater than the length of the relatively outwardly disposed distal free end terminal.

0 0 0 ·· 0

0 0 0 • 0

0 0 0 0 0 0

Alternatively, the base length of the side panel attachment zone 94 may be less than the length of the distally extending, outer free end section 92. Optionally, the side panels may have a substantially rectangular quadrilateral or substantially regular trapezoidal shape.

On each of said side panels 90, a stress transfer carrier section 98 may be formed along its outer free end section 92 to provide a more even distribution of tensile stresses across the area of the side panel. The transfer section is designed to have a relatively high stiffness value, and in the preferred embodiments desired, the transfer section extends over substantially the entire length of the outer free end section 92 of the side panel in the longitudinal direction. To each of the side panels 90, a fastening tab 44 may be attached in a transverse direction extending outwardly relative to the transfer section of the side panel to provide a firm and reliable securing of the waistband portions of the absorbent article to the body during use. panel.

Each fastening tab 44 may include a backing layer 56 that connects to one another an inner edge of a portion of a selected fastening component, for example, a hook material 46, associated therewith and a corresponding external free end section of the side panel 90. The backing layer has an internally disposed first a lateral region and a second lateral region disposed transversely outward. Said first side region is laminated to or otherwise suitably coupled and secured to the side panel by means of a functional structural bond. The side panel material, carrier layer material, and structural bonding configurations are formed and arranged such that, in combination, they form a functionally active transmission section 98 to transmit the applied stresses. Optionally, an additional layer of reinforcing material may be provided on the transmission section 98 to transmit the applied stresses in order to increase its stiffness and further improve its ability to distribute the applied stresses over the entire length dimension of the side panel.

The inner side region of the support layer 56 may have a longitudinal extent that is smaller than the length dimension of the outer free end section 92 of the side panel 90 in the longitudinal direction. Alternatively, the support layer 56 may have a range in the longitudinal direction, the size of which is substantially equal to or greater than the length dimension of the outer free end section of the side panel in the longitudinal direction (see, for example, Fig. 1).

The above-mentioned piece of hook material 46 is laminated to, or otherwise suitably coupled to and attached to, the outer lateral region of the backing layer through a functional structural bond through lamination. Specifically, in the illustrated embodiment, a portion of the hook material 46 is laminated in particular to an inwardly facing front skin-facing surface of the backing layer such that the hook elements extend inwardly relative to the absorbent article. According to the illustrated embodiment, the outer transverse edge of the second side region 60 of the backing layer coincides with the outer end transverse edge of the hook material portion 46. Alternatively, said outer transverse edge of the second side portion 60 may be in a transverse direction.

• 4 • 444 • 4 • 4

4 4 • 4

4 • • 4 4 4 • 4 4 4 • 4 4 4 4 4 4 4

44 of the side region 60 of the backing layer is arranged so as to be offset a certain distance in the transverse direction relative to the outer end transverse direction of the hook material portion 46. In either case, however, in both embodiments described, the distal edge of the hook material portion 46 provides a lateral end edge of the absorbent article.

The longitudinally extending, relatively outer edge of the side panel 90 may be spaced, spaced apart from the longitudinally extending inner edge of the selected fastening component, e.g., the substrate substrate. More specifically, the outer edge of the side panel 90 may also be spaced apart by a pitch distance from the relatively inner edge of the hook material portion 46. This pitch distance optionally has a transverse direction that is equal to or greater than the mounting range. in the transverse direction. In addition, the inward facing face of the wearer faces the surface of the carrier layer 56 configured to exhibit a limited ability to engage functionally with the hook members 54. As a result, the fastening tab 44 may be configured and configured according to the longitudinally extending fold line. An optionally desired location in the fastening region 50 folded into a nonfunctional storage position in which the hook elements are disposed on and coupled to a face facing the body surface of the backing layer 56. The engagement intensity between the hook material piece and the backing layer is required only in to an extent sufficient to maintain the inoperative storage position. In view of the above, this engagement intensity can be assured by applying a maximum peel force of between about and about 50 grams. .

In specific embodiments of the present invention, the carrier layer 56 may be formed of a substantially non-elastomeric material, such as, for example, polymeric films, woven fabrics, nonwoven fabrics, or the like, as well as combinations thereof. Alternatively, the backing layer material may consist of a substantially elastomeric material, such as a stretched laminate (SBL), a tapered laminate (NBL), an elastomeric sheet, an elastomeric foam, or the like, as well as their combinations. Said elastomeric material is elastically extensible at least in the width direction 88. The backing layer material may consist, for example, of a laminated fabric (SMS), comprising a core of a blown deposit layer sandwiched between two face-to-face facing and bonded layers, in the described composite arrangement, it has a total basis weight ranging from about 50 to 67 g / m ² (about 1.5 to ounces per square yard (oz / yd ² )). According to another embodiment, the carrier layer material may consist solely of a spunbond nonwoven fabric having a basis weight in the range of about 50 to 67 g / m ² (about 1.5 to 2 oz / yd ² ).

Mechanical functional fasteners used to cooperate with various embodiments of the present invention can be provided by interlocking fasteners of a mechanical type, such as hooks, snap fasteners, snap fasteners, knobs, and the like which: 0 · ** ** ** ** ** ** ** ** ** ** ** ** «** **

4 »♦ · * · φ

(90 * include interlocking and complementary, mechanically interlocking and interlocking components. According to specific aspects of the present invention, the fastening means may be provided by a hook and loop fastening system, anchor and loop fastening system or the like These fastening systems generally consist of hooks or hooks of similar elements and cooperating stitches or eyelet-like elements in which said hooks engage and engage with each other. It is desirable that the interlocking coupling be optionally detachable or releasable, known in the art, standard fastening systems are commercially available, for example under the trade name VELCRO R.

Examples of suitable hook and loop fastening systems (Velcro) are described in U.S. Pat. No. 5,019,073, issued May 28, 1991 to T. Reossler et al., The entire disclosure of which is hereby incorporated by reference in its entirety. Other examples of such hook and loop fastening systems are described in U.S. Pat. No. 366,080, entitled High Fear Tear Valve, by G. Zehner et al., Filed Dec. 28, 1994 (Verified Annotation and Brief Content No. 11,571), which was published as U.S. Pat. 5,605,735; and U.S. patent application Ser. No. 421,640 entitled Multi-Piece Fastening System, filed on April 13, 1995, by P. VanGompel et al., The entire disclosure of which is hereby incorporated by reference in its entirety. Examples of fastening flaps provided with a carrier layer 56 are described in the patent

0 0 9 · ♦ · φ * · · 0 9 0 9 9 0 0 0 ·

0 00 90,990 00 9

0 0009 0000

900 0099 90 99 09 No. 08 / 603,477, entitled Functional Gripping Fastening System by A. Long et al., Filed Mar. 6, 1996 (Verified Annotation and Brief Content No. 12,563), which was published as U.S. Pat. 5,624,429; the entire description of which is hereby incorporated by reference into the present invention in the sense corresponding to its nature.

In a specific embodiment of the hook and loop fastening system, a portion of the hook material 46 is operatively coupled and coupled to the fastening tab 44, while the loop material 80 is used to form at least one cooperating fastening suction section 78. For example, said suction section may conveniently be positioned on an exposed, unprotected, outer facing front surface of the backsheet 22. As mentioned above, an alternative configuration of the hook and loop fastening system may be arranged such that the loop tab 44 is attached with the loop material while the hook material is used. to form a fastening suction section 78.

According to specific aspects of the present invention, the piece of hook material 46 may be formed from a material commonly referred to as a micro-hook material. A suitable micro-hook material usable for this purpose is distributed under the trade name CS200 and is marketed by the 3M Company, with the trade name of St. Paul, Minnesota. This micro-hook material may be provided with hook-like hooks with an extended head and may be configured with a hook density of approximately 1,600 hooks per square inch; wherein the hook height is in the range of about 0.033 to 0.097 cm (about 0.013 to 0.038 inches) and width

4 4 4 4 4 4 · 4 444 «4 * 4 4 hook heads range from about 0.025 to 0.033 cm (about 0.01 to 0.013 inches). These hooks are rigidly bonded to a thin film backing substrate having a thickness of about 0.0076 to 0.01 cm (about 0.003 to 0.004 inches) and a Gurley stiffness of about 15 mg.

Another suitable and useful micro-hook material is that distributed under the trade name VELCRO CFM-29 1058 and marketed by Velcro U.S.A., Inc., with a commercial office in Manchester, New Hampshire. This micro-hook material may be provided with hooks in the form of angled hook elements and may be configured with a hook density of about 264 hooks per centimeter square (about 1,700 hooks per square inch); wherein the height of the hook is in the range of about 0.010 to 0.063 cm (about 0.012 to 0.025 inches) and the width of the hook is in the range of about 0.007 to 0.022 cm (about 0.003 to 0.009 inches). These hook elements are formed by coextrusion with a thin film backing substrate having a thickness ranging from about 0.0076 to 0.008 cm (about 0.003 to 0.0035 inches) and a Gurley stiffness of about 12 mg.

For the purposes of the present invention, the different values of unsupportability and stiffness are determined with respect to the bending moment generated by the force whose direction of action is oriented perpendicular to the plane of the test component being subjected, defined essentially by its width and length. A suitable and convenient technological procedure for determining in the description of said stiffness values is provided by the Gurley Stiffness Test Test, the complete description of which is given in TAPPI Test Standard T 543 om-84 (Paper Bending Stiffness). Gurley stiffness tester))). An appropriately satisfactory test apparatus for this purpose is the Gurley Digital Stiffness Tester: Model 4171-D, manufactured and marketed by Teledyne Gurley, with a sales office in Troy, New York.

In various embodiments of the present invention, the stitch material may consist of a nonwoven, woven or knitted fabric. A suitable fabric useful as an eyelet material may consist, for example, of a double warp knit fabric, marketed by Guilford Mills, Inc., of Greensborough, North Carolina, under the trade designation # 34285, as well as other commonly used knitted fabrics. . Also suitable and suitable materials for this purpose are the materials with regularly spaced woven nylon guides, which are commercially available. by 3M Company under the trade name SCOTCHMA.TE. In addition to these materials, 3M Company distributes other materials, such as separate loops forming a web without a substrate and provided with an adhesive on the back, or knitted strips with loops.

According to specific aspects of the present invention, the placement of the stitched material need not be limited to a separate, separate suction section. Instead, the eyelet material may be secured, for example, by a substantially continuous, extending fibrous layer that is formed integrally extends over substantially the entire exposed surface area of a fabric similar to the extending protective layer used as part of a diaper 20. it follows that the eyelet material can also be secured by a fabric-like backsheet 22, by means of which it is possible to achieve an effective fefe fe feef fe fe fe Fefe fefe fefe fefe of the functional coupling of the automatic mechanical fastening system at virtually any location located on said lower backsheet. In practical terms, the extent of applicability and arrangement of the stitched material will depend only on the cost of the material.

The fasteners may, in various embodiments of the present invention, be functionally coupled to their underlying substrate using any one or more attachment means also used to form and interlock the various other components of the absorbent article. It is desirable that the fasteners of the various base and complementary fastening regions can be formed integrally, for example by molding, coextrusion or similar technological processes, together with the underlying substrate. Thus, the substrate and the fasteners may be formed of substantially the same polymeric material, which eliminates the need for a separate manufacturing operation of fastening the fasteners to a previously formed substrate substrate formed in a separate manufacturing operation. In the illustrated embodiments of the primary fastening region, the hook elements may be formed integrally with the substrate, for example, by coextruding the substrate and the hook elements of substantially the same polymeric material.

From the above, it must be understood that the strength of said interlocking or other interlocking connection between the substrate and the respective fastening component must be greater than the maximum force required to tear off the fastening tabs 44 from its releasable engagement engagement. · 0 0 0 0 0000

0000000 00 coupled to the respective suction section of the absorbent article.

Computational methods and testing procedures

Procedure for determining the thickness in a partially saturated state

The thickness (h) of each layer in a partially saturated state can be determined based on the previously determined input variables and parameters, using the following procedure:

Goal:

Determining the thickness (h) of each layer portion in a partially saturated state.

Equipment and materials used:

Glass Petri dish (100 x 15 mm - No. 3160-101 Fisher's catalog number 08-747C).

Blood Saline, for example, Blood Saline Catalog No. 8504, available from Stevens Scientific, a division of Cornwell Corporation, with offices in Riverdale, New Jersey; or equivalent.

0.05 psi (0.345 kPa) thickness measuring apparatus with a 3 inch (7.62 cm) diameter base.

Cutter - 3 inch (7.62 cm) circumferential diameter.

Laboratory scales.

Laboratory stopwatch.

Testing procedure

Cut a 3 inch (7.62 cm) diameter test piece to be subjected to a punching die.

Calculation of saturation (v: g / g - mass of liquid in grams per mass of test sample in grams) of the layer, based on saturation of 0,6 g / cm ^{2 of the} mixture of absorbent and superabsorbent material; and applying the process described in paragraph Flow conductivity calculation.

Weigh the test sample in the dry state and record its measured mass.

Calculation of the amount of liquid saline to be added to the test sample for testing purposes by multiplying the dry weight of the test sample by the value of the desired saturation level.

Dispense the calculated amount of liquid saline into a petri dish and disperse it over a flat surface to distribute the solution evenly into the test sample.

Place the test sample in a petri dish so that it remains straight.

Remove the test sample from the petri dish after 30 minutes.

Measure the thickness of the test sample (in: mm) under a controlled limited pressure of 0.05 psi (0.34 kPa), and record its measured size.

Obtained values of thickness (h) in partially saturated. condition can be applied in the equations used to calculate the flow conductivity of the composite absorbent system.

Flow conductivity calculation

The flow conductivity of the absorbent core when the absorbent material is loaded with a liquid of 0.6 g / cm ² to express the absorbency and absorbency of the absorbent core structure when the absorbent core is in a partially saturated state. Flow conductivity can be characterized by the following equation:

Flow conductivity value = K ₂ h ₂ + K ₂ h ₂ + K ₃ h ₃ +. .

where: K is the permeability of each layer at a fixed saturation; and h is the thickness of each layer at a fixed saturation.

The transmittance (K) of each layer in the absorbent core can be calculated as follows:

Each layer present in the absorbent core represents a combination of substantially non-swellable fibrous materials and superabsorbent material in the form of particles, fibers or flakes.

The mathematical expressions of permeability (K) for the structural set of cylindrical, irregularly oriented elements and for the set of spherical particles are as follows:

For cylindrical and other, regular or irregular, elongated fibrous form configurations:

- 96 * 0 · · · ···· · · 0000 0 · 0 ·

0 · 0 · ···· 0000 ·· ·· ·

0.30 ε _{κ = (} _-------) ₍₁ _ _{ε) (} -----—) ² ' ⁵ (SA / y) ² 1 - ε

For generally spherical and other, regular or irregular, particle shape configurations:

0,3555 ε

K _{= (} --------) ₍₁ _ _{ε) (} --------> 2.35 (SA / y) ² 1 - ε where: SA / V is the surface area to volume ratio and ε is the void content, expressed as the ratio of the pore volume (s) to the total volume of the substrate as a whole.

The basis for the above-mentioned mathematical expression of permeability (K) is the publication Low Reynolds Number Hydrodynamics

Reynolds number), by Happel and Brenner, Noorhoff International Publishing (1973). The mathematical expressions of permeability for cylindrical and spherical particles were derived based on the facts presented in the above-mentioned publication by their application to the simpler, above-described shape configurations to obtain the values of the respective scalptors and multipliers.

It has been found that all of the liquid supplied to the absorbent structure during the first impact is substantially absorbed by the superabsorbent material before the second or subsequent subsequent impact of the liquid and the next occurs. In view of this finding, for the purpose of calculating the permeability value necessary to calculate the flow conductivity value, all the liquid specified above (at 0.6 g / cm ² ) is considered to be absorbed by the superabsorbent material. Therefore, when calculating the values of the ratio of the voids content (ε) to volume and the surface area to volume for the superabsorbent material, the volume of this liquid is included as part of the solid particle volume. In this state, the voids content (ε) of the relevant material is determined by:

ε = l- [(solid particle volume 7- liquid volume) / (total wet test volume)] where: the total wet test volume is the value that represents the product of the area and the measured thickness of the test sample. Said thickness of the test sample may be determined, for example, based on the above-described Partially Saturated Thickness Detection Procedure.

The surface area to volume ratio (SA / V) used in the respective formulas and equations to calculate the permeability of various components is calculated based on the surface area per volume conversion for either fibers or particles, according to the respective morphology of the individual components. For fibers, the surface area to volume ratio is equal to the circumference to cross-sectional area perpendicular to the longitudinal axis of the cylindrical member.

For a cylindrical element with a circular cross-section, this ratio is determined, for example, as follows:

• · fe ·

SA / γ = p / _a = 2 / r;

where: r is the cross-sectional radius of the cylindrical element in cm.

For tape-shaped configurations and the like, i. those configurations whose cross-section has the shape of a general quadrilateral, the said ratio shall be determined using the formula:

SA / y = p / _a - 2. (width + thickness) / (width. Thickness)

In the case of fibers having a more complex cross-sectional configuration, the circumferential to cross-sectional area ratio can be determined using well known microscopic techniques. See, for example, Quantitative Stereology, E.E. Underwood, publ. Addison Wesley Publishing Co. (1970).

Based on these relationships, the ratio of the surface area to the volume of substantially non-swellable fibrous materials can be determined by means of the SA / V value (or ratio of fiber surface area to fiber volume) corresponding to the respective cross-sectional shape configuration of the fibers. For example, the cellulose-based fibrous fluff typically has a shape similar to an elongated strip with a rectangular cross-section. Then, for cellulose-based fibrous fluff with a thickness of 8 microns (0.0008 cm) and a width of 40 microns (0.0040 cm), the surface area to volume ratio will be:

- 0 0 0 0 ·

000 000 ·

SA / y = p / a = 2. (8 + 40). 10 ' ⁴ / ((8.40). 10' ^e )

SA / γ = 3000 cm ^-1

The superabsorbent material may, in terms of its morphology, be in the form of particles, fibers, flake elements or combinations thereof. In addition, these materials may be isotropic or anisotropic in terms of their swelling capacity. The vast majority of commercially available superabsorbent materials are in the form of particles that swell isotropically. Such superabsorbent particles can be considered as spherical particles for purposes of the present calculations. For the preliminary calculation of the surface area to volume ratio of the superabsorbent material, it is possible, provided that the sizes of all such particles are substantially identical, to calculate the surface area to volume ratio for the spherical elements (spheres). The ratio of the surface area to the volume of the spherical element is determined by:

SA / y = 3 / y;

where: r is the radius of the spherical element in cm.

However, superabsorbent materials may also consist of particles with a particle size distribution. In the case where this distribution is substantially mono-modal, the surface area to volume ratio can be calculated by weight. For a given particle size distribution, the ratio can be calculated using the following formula:

- 100 3.Σ7, (r / .nj

SA / y = -------------;

where: r _± is the mean radius of the particle in the i-th fraction; n _± is the number of particles in the i-th fraction, where:

n _± = [p _SAP . (3/3) .n. r _± ³ ] where: ια _± is the mass fraction of particles in the i-th fraction, in grams;

PSAP Õ ^ê density solid particles of superabsorbent material in a dry state g / ^cm3.

In the case of a multimodal distribution, for example a bimodal distribution, the permeability must be calculated separately for each modal group of particles based on the use of the specific permeability calculation of the composite materials described in detail below. In view of the above, in this case, the calculation of the surface area to volume ratio by weight conversion must be performed separately for each modal group of particles. Typically, for at least 6 to 8 fractions with different particle sizes, a preliminary calculation of the particle size distribution of the superabsorbent material must be used.

In addition, the contribution and benefits of incorporating superabsorbent material to determine the permeability of the composite absorbent system complicate its swelling due to liquid uptake. Specifically, size, and given i

101 to * to this · to · to · to · to · to · to · to ··· ············· The ratio of surface area to volume of superabsorbent material particles will depend on the saturation level of the material.

The relationship for calculating the surface area to volume ratio of isotropically swelling superabsorbent material particles as a function of the liquid content is:

^(SA / V), dry ^(SA / V) ----------------------- _wet;

[1 + (Sp _SAP / _Pj )] < ^1/3 >

where: ( ^SA / v) _we t ίθ surface area to wet superabsorbent volume in cm -1;

S is the saturation of the superabsorbent material expressed as the amount of liquid in grams to the weight of the superabsorbent material in grams;

p _SAP is the dry particulate density of the superabsorbent material, in g / cm ³ ;

p ₂ is the density of the liquid, in g / cm ³ ;

(SA / _{nozzles are} yj j _e ratio of surface area to volume of the superabsorbent material particles in the dry state, in cm "l.

Superabsorbent materials may also be present in fibrous form. Accordingly, it has been found that fibrous superabsorbent materials generally swell anisotropically. This means, in particular, that in order to increase the volume of the fibers with increasing liquid content, it takes place first in the radial direction, while the length of the fibers remains substantially constant, that is to say unchangeable. In this case, the ratio of the surface area to the volume of the swollen fibers of the superabsorbent material is as follows:

102 • • • • • • • • • • • • • fefe ( ^SA / V) _dry ( ^SA / V) _wet = -------------------- [ 1 + ( _{SAP SAP} / pf] ^(1/2)

Based on the above relationships to calculate the surface area to volume ratio as a function of the liquid content of the superabsorbent material, it is possible to calculate the specific surface area to volume ratio of the superabsorbent material at a specific liquid content. Before performing the actual calculation of the individual surface area to volume ratios of each superabsorbent material to be used for the permeability calculation based on the above mathematical relationships, the saturation level of each superabsorbent material in each absorbent layer must be determined. The following theoretical considerations describe the procedure used to pre-calculate the saturation level of each superabsorbent material present in the absorbent core.

It has been found that in the time interval between the liquid supply during its first and second impact, substantially all of this liquid is absorbed by the superabsorbent material contained in the system. Furthermore, it has been found that the liquid fed to the absorbent structure during its first impact is distributed between the superabsorbent materials present in accordance with their relative proportions and relative liquid uptake rates. For the load specified above, the saturation, Sj, expressed in grams to the weight of the superabsorbent material in grams, of each superabsorbent material contained in the absorbent core can be calculated by the liquid (0.6 g / cm ² ', amount ratio).

according to the following relationship:

(BWJ. 10 ^"4) where: BWJ the basis weight of the jth superabsorbent material in g / m ^2;

fpj is the liquid partition coefficient of the j-th superabsorbent material.

The liquid partition coefficients, fp, are calculated for each superabsorbent material contained on the basis of their relative amount and relative liquid uptake rate using the formula:

fRj-bWj fpj = ^S pfRj- ^bw p where: bWj is the basis weight of the j-th superabsorbent material, in g / m ² ;

is the coefficient of relative liquid uptake of the j-th superabsorbent material.

The coefficient of relative liquid uptake rate for each superabsorbent material contained is given by:

104 • 4 · 4

4

4 4 4

4 · ·

4 * ····

7¾ = where: is the absorption time (timing) required to congest 60% of the value of the balanced absorption capacity of the j-th superabsorbent material, determined on the basis of the Zero Load Inundation Capacity Test (FAUZL) detailed below.

For purposes of illustration of the calculation method, an example is considered. two-layer absorbent structure with the following composition:

Layer 1:

Type 1 superabsorbent material with a recalculated particle size of 400 microns and a basis weight of 120 g / m ² ;

Γ] is 5 min;

Technical cellulose in the form of fluff fluff with a basis weight of 120 g / m ² and a fiber cross-section of 8 microns x 40 microns;

The thickness measured at the saturation level specified below is 0.55 cm.

Layer 2:

Type 2 superabsorbent material with a recalculated particle size of 400 microns and a basis weight of 150 g / m ² ;

T ₂ is 1 ° min;

Technical cellulose in the form of fibrous fluff

105 * · «· · · · · · · · · · · · · · · · · · · ·

a basis weight of 130 g / m ² and a fiber cross-section of 8 microns x 40 microns;

The thickness, measured at the saturation level specified below, is 0.51 cm.

For superabsorbent materials used in the above layers:

A = 5 / 5-1;

A = 5/10 = 0.5;

and

1.120 fpi = 0.66;

(1,120 + 0.5,150)

1.150

Tp ₂ = 0.38;

(1.120 + 0.5.150) where:

(0,62.0,6)

Cheese = ----------- = 31 g / g (120.10 ⁴ )

106 • · 0 · 0 0 0 ··· <> • 0 0 0 000 0 * · 0 • · · 0 0 · · 0 0 0 0 0 0 0 0 0 0 0000

000 0000 00 00 00 «0 (0.38.0.6)

S ₂ = ----------- = 15.2 g / g (150.10 ^-4 )

The above calculations correspond only to cases where the total balanced capacity of FAUZL superabsorbent materials is not exceeded at a specific liquid load of 0.6 g / cm ² . If the capacity of a particular particular superabsorbent material is exceeded under these conditions, its saturation is set to be assumed to be stored excessively in the other contents contained in the equilibrium value, wherein the amount of liquid superabsorbent materials is in a manner consistent with the facts set forth herein.

Based on the amount of liquid located in the superabsorbent material, it is possible to calculate the respective surface area to volume swollen particle or fiber ratios for each of the superabsorbent material in the swollen state using the above equations for calculating the surface area to volume ratio. absorption. layer. For particulate superabsorbent materials, the equation for calculating the permeability of spherical particles must be used, and for fibrous superabsorbent materials, the equation for calculating the permeability of cylindrical, elongated particles must be used.

In this particular example, the superabsorbent materials take the form of particles, so that the respective surface area to volume ratios when the absorbent core contains 0.6 g / cm ^{2 of} liquid are, using the corresponding equations, as follows:

107

Superabsorbent Material Contained in Layer 1:

(Wv) _{SAP x} = ------—------------- [1 + (S. _Psap / _Pl )} ^

3 / (200.10 ' ⁴ )

----------------------- 4i _z (j _cm ^_1 [1 + (31.1,48 / 1)] ^(1/3 >

Superabsorbent material contained in layer 2:

^ ^SA / V} _dry (SA / y) _{Sn 2} = = [1 + (S. _Psap / _Pl )] ^(1/3)

3 / (200.10 ' ⁴ )

------------------------- = 52.4 cm ^-1 [1 + (15.2.1.48 / 1)] U / 3)

Technical cellulose in the form of fluff, contained in the two layers mentioned above:

SA / y = p / a = 2. (8 + 40) .10 ' ⁴ / ((8.40) .10' ⁸ )

SA / y - 3000 cm ^-1

In this state, it is then possible to determine and adapt the relevant equations for determining the throughput for the calculation ·· ·

The permeability of the particular components contained in the individual layer portions used to form the absorbent core of the composite absorbent system based on the above-mentioned mathematical permeability expressions for the fiber or particle structures. However, the aforementioned mathematical permeability expressions for the structural sets of fibers and / or particles are only valid if the overall porous substrate contains either only fibers or only particles of superabsorbent material dispersed in its volume. Where both particles and fibers are contained in the volume of the respective substrate with a specific inter-mesh, they are used to calculate the combined equation. The procedure used to combine the relevant mathematical equations is based on the principle of the self-agreeing method proposed, with theoretical explanation, and described in the article Performing Predictions by Selfconsistent Method and Finite Element Simulation, authors of AL Berdichevski and Z. Cai, publ. In Polymer Composites, No. 14 (2), (1993).

For the purposes of the present disclosure, the basic prerequisite, set against the background of said self-agreement method, is that the permeability is substantially homogeneous throughout the volume of the porous substrate. Accordingly, the local void values corresponding to the presence of fibers or particles are determined such that their respective local permeability is equal. The above calculation is subjected to limitation so that the total void density (ε _{σοΛ? Ρ} ) of the composite absorbent structure is maintained at a specific value, which is determined based on the measured surface area and thickness of the test sample as described above.

109

4 <4> 4 4 4 4

The simplest composition of the composite layer comprises two components. In this case, two equations will be needed to calculate the permeability of the composite layer based on the self-agreement method. For the aforementioned exemplary embodiment comprising two composite layers or layer portions, the following equations will be used to calculate the permeability of the composite absorbent structure based on the self-agreement method.

The equations for calculating the permeability of layer part 1 and layer part 2 have the following form:

Layer Part 1: for fibrous material:

θ ^{'30 s} fiberl

Kfiberl ⁼ () ( ¹ “ ^ε fiberl> () (3000) ² 1 - c _Iltxa for superabsorbent material:

0, 3555 ^£ sap i

The SAP and ^the SAP i) () (41, 6) and SSAP ² 1

Layer 2: for fibrous material:

0.30

Kfiber2 ~~ ^ε fiberZ · (3000) ^{2 ε} fiberZ ^ε fiber2

2.5

110 · 0 0 · 0 · 0 · 0 · t · 0 · ^β · 00 0000 ·· «For superabsorbent material:

0.3555 ^ε SAP 2

SAP 2 () (1 ε _{SAP 2} ) (

2.35: 52.4:

SAP 2 where: e _flberl , ε _{3ΆΡ lf} e _fíber2 and _{sňP 2} correspond to the local _voidness values of the respective fibrous and superabsorbent materials contained in the layers 1 and 2. The sum of the local voidness must give the corrected total voidability ( _comp ), described in detail above, and the following relationship:

b »t _coap . ΙΟ ^'5 [Σ * (f _/ f _k) + S. (// _Pjl + Σ ^)

P = 1 ----------------------------------------------- ^c comp ^x fo-comp where: bwt _conp is the basis weight of the composite, in [g / m ² ] f _k is the weight fraction of the k-th fibrous material contained in the composite;

fj is the mass fraction of the j-th superabsorbent material contained in the composite;

whereas:

Σζ f _k +2. f ₃ - ia

Pk is the density of the k-th fibrous material, in g / cm ³ ;

P i is the density of the j-th superabsorbent material, in g / cm ³ ;

• ·

111

0 0 0 0

Pi is the density of the liquid, in g / cm ³ ;

Sj is the saturation level of the superabsorbent material, expressed as the amount of liquid in grams to the weight of the superabsorbent material in grams;

^ comp ΐθ thickness (h) of the composite at a liquid loading level equal to the total liquid loading of the composite, said total liquid loading of the composite being determined by the formula:

For the above-mentioned exemplary embodiment, comprising two composite layers, each consisting of only one type of fibrous material and one type of superabsorbent material, will then be. a total density of fibrous materials in both layers of 1.5 g / cm ³ , and a total density of superabsorbent materials in both layers of 1.48 g / cm ³ ; other variables such as the weight of the fractions of superabsorbent material, the liquid load, and the individual heights of each layer of the composite structure are determined using the above relationships.

Total gap values are calculated as follows:

Layer 1:

240.10 ⁴ [(0.5 / 1.5) + (0.5 / 1.48) + (31.0.5)]

8 = 1

0,29 comp

112

Layer 2:

450.10 ^-4 [(0, 67/1, 5) + (0.33 / 1, 48) + (15.2.0, 33)] ε = 1 --------------- ------------------------------- 0.50 h-comp

The permeability values of the two layer lots, which were calculated on the basis of the aforementioned self-agreeing method, are as follows:

Layer 1:

K = 1.6.10 ⁶ cm ² ;

Layer 2:

K = 1.1 x ^{10 6} cm ² ;

A simple exemplary embodiment of a dual-layer absorbent structure serves to illustrate the permeability of the composite structure for purposes of illustration. However, the composites used to form the absorbent core of the present invention may comprise more than two different components. Thus, in such cases, if the permeability calculation of the composite structure is based on the use of the self-agreement method described above, it is necessary to derive corresponding mathematical permeability expressions for each component included in each given composite layer portion of the absorbent structure. For example, when the respective composite layer portion. contains two types of fibrous materials and two superabsorbent materials, using a self-agreeing method for mathematical

113> »· ♦ absorbent structure to calculate the necessary four equations to calculate the permeability of each of the contained materials.

On the basis of the calculated permeability values of the composite absorbent structure and the thicknesses (thickness size h), it is now possible to calculate the desired flow conductivity value of the absorbent system for each layer portion of the absorbent core found in the partially saturated state as calculated above. In this state, see above, it is therefore:

Flow conductivity value = + K ₂ h ₂ + K ₃ h ₃ +. .

So, for an exemplary embodiment comprising two layers is:

Flow Conductivity Value = = (1.6 · 10 ~ ⁶ · 0.55) + (1.1 · 10 ~ ⁶ · 0.51) =

- 1.4 · 10 ^{-6 cm3.}

Although the above calculations of permeability and flow conductivity are exemplified only for a two-layer absorbent structure in which each of the outer layers comprises one isotropically swellable superabsorbent material and one type of fibrous material, the above detailed flow conductivity calculation may be extended to cases including more than two layers, as well as the permeability calculation (K), in accordance with the present disclosure, can easily be adapted to calculate the permeability of more complex materials composed of multiple components.

114

Potential water absorption value

Set goal

This test is used to determine the ability of the absorbent material to remove liquid from the acquisition zone.

Brief summary

Determination of the amount of liquid to be applied to a test sample based on the above calculations using the liquid partition coefficient. Allowing the test sample to absorb liquid in the reservoir and determining the amount of liquid that has been withdrawn from the receiving zone.

Used equipment and materials

A sheet of plexiglass or similar material, measuring 21 cm x 21 cm and having a thickness of 5 mm or less.

Suitable liquid reservoir.

Laboratory scales.

Holder for holding a test sample of absorbent material in the vertical position during fluid replenishment.

Quick-release clamps for attaching a test specimen to a Plexiglas plate, such as Medium Binder Clip, Catalog No. 10050, marketed by IDL Corporation, Caristadt, New Jersey.

Laboratory oven with heating to 150 °.

115

0

00 0 «* · 0 0 0 0 · ··· · 0 · 0 ·· 000 00 0 ·············· · · 0 0 0 0«

Tested materials

Test liquid saline; blood saline, marketed under catalog number 8504 Blood Bank Saline by Stepehns Scientific, a division of Cornwell Corporation, with a sales office in Riverdale, New Jersey; or equivalent.

Preparation of the test sample

Taking the layer test sample from the absorbent article to be tested or removing the respective layer test sample without breaking so that it has the same configuration as the layer in the absorbent article. Each absorption layer must be separated from the other components and tested separately before testing.

Marking the receiving target position using an indelible ink marker. The receiving target position of the test layer is determined based on the intended arrangement of the layer in the finally finished absorbent core. This receiving target position is located in a transverse centered region that is located inwardly from the forward limit end edge of the furthest forward extending absorbent layer of the absorbent core by a distance equal to 36% of the total length of the absorbent core. Accordingly, it is not necessary to test this furthest extending absorbent layer of the absorbent core.

Identification of the receiving zone on the test specimen using an indelible ink marker. Reception zone

The test sample of the test layer is determined based on the intended arrangement of the test layer in the finally finished absorbent core. This test zone receiving zone of the test layer is that zone of the test sample that lies between two lines extending in the transverse direction. The first of these lines is located inwardly from the leading edge end edge of the furthest forward extending absorbent layer of the absorbent core by a distance equal to 24% of the total length of the absorbent core. The second line is positioned inwardly from the leading edge end edge of the furthest forward extending absorbent layer of the absorbent core by a distance equal to 59% of the total length of the absorbent core. Both lines are substantially perpendicular to the longitudinally extending axis of symmetry of the absorbent core. In the case where the two lines of the acquisition zone do not fall into and are outside the limit end edges of the test sample of the test absorbent material, then the liquid wicking value of the test sample will of course be zero.

Determining the amount of liquid to be absorbed by the test sample using calculations by means of the liquid partition coefficient based on the above detailed description regarding the calculations for determining the flow conductivity value. However, rather than calculating the saturation of the superabsorbent material for each individual layer, the predicted amount of liquid contained in each absorbent layer is determined. This calculation can be performed using the following formula:

The amount of liquid contained in the absorbent layer j = (fpf-1/0 x surface area of the acquisition zone)

117 * 9 * 000 (for example, for an exemplary embodiment, determined in connection with the description of the flow conductivity determination), and for a receiving area of 100 cm ² , the following values are obtained:

61.6 grams of liquid in the layered portion 1, and an amount of 38.4 grams of liquid in the layered portion 2).

Procedure for preparation of test conditions

Placing a test specimen mounted on a plexiglass plate using quick clamps so that the indicated target position is located directly at the bottom of the test apparatus.

Fill the reservoir with liquid so that the liquid level is approximately 1 cm from the top edge.

Place the liquid reservoir on the laboratory scale pan.

Testing procedure

Laboratory balance balancing.

Hanging the test sample into the reservoir so that the absorbent material to be tested contacts the liquid level.

The use of laboratory weights for the purpose of comparing the absorbent amount of liquid absorbed by the absorbent material with the amount determined on the basis of the calculations described above. Removal of the test sample from the reservoir at the time when the quantity of liquid to be weighed matches that of the liquid, determined by means of the partitioning calculations

118 fe liquid coefficient, ± 5 g / m ² .

Fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe · fe ·

Leave the specimen at rest for 5 min in a vertical position.

Cut the test specimen at the positions indicating the receiving zone and remove the formed central portion. Weighing of the remaining sections of the test sample.

Dry the remaining sections of the test sample in a laboratory oven where these samples are left overnight.

Weighing the dry test specimens and determining the difference between the wet and dry weights by subtracting the dry weight of the test sample from the wet weight of the test sample, the difference being the amount of liquid that has been transferred from the receiving zone. The amount of liquid removed from the acquisition zone (i.e., the amount measured in the preceding step) is divided by the total amount of liquid that was applied to the absorbent layer in the liquid absorbency test; whereupon the calculated fraction is multiplied by 100. The result is the value of the potential absorbency of the liquid-tested layer portion.

Combined conductivity / water absorption (C)

The combined conductivity / water absorption value can be determined based on the following equation:

(LWV)

C = (FCV) + (3.10 ⁷ )

0

0 0 0 0 0

119 ·· ·· Μ • · 0 0 0 ♦ · · 000 where: FCV is the flow conductivity in cm ³ ; LWV is the liquid wicking value; and (3.1O ⁶⁾ has a dimension of cm ^-3.

Modified absorption absorption under load

Set goal

This test is designed to measure the ability of particulate superabsorbent polymeric material (SAP) to absorb saline under a constant 0.3 psi (2.07 kPa) load. More specifically, the test serves to measure the amount of saline absorbed by an amount of 0.160 grams of superabsorbent polymer material having a particle size falling through a # 30 mesh (US standard) and retained on a # 50 mesh (US standard) sieve that is distributed on a desktop of size

5.07 cm &lt; ^{2 &gt;} and subjected to a pressure of 0.3 psi (2.07 kPa). A suitable test apparatus is shown in FIG. 10 to 14.

Used equipment and materials

Electronic scales with an accuracy of 0.001 grams (minimum load capacity 200 grams).

Cylinder assembly: a plastic cylinder 120 having an internal diameter of 1 inch (25.4 mm) provided with a 100 mesh stainless steel mesh attached to the bottom of the cylinder; plastic disk piston 122 weighing 4.4 grams and 0.995 inch (25.27 mm) in diameter. The diameter of the disc piston is 0.005 inch (0.13 mm) smaller than the inner diameter of the cylinder.

120 • 0 • 000

Weights 124 weighing 100 grams having a diameter of 0.984 inches (25 mm).

0.9% sodium chloride (NaCl) solution in blood saline.

Saline tank 126.

An electronic timer 140 capable of reading and reading for 200 minutes at 1 second intervals.

Weighing paper.

A network test assembly, standardized to U.S. Pat. Standard Testing Sieve (A.S.T.M. E-11 Specification), comprising one receiving tray, one # 30 mesh screen, one # 50 mesh screen, and one lid.

A tapping device arranged above the test sample and intended to ensure adequate and consistent tapping on the plate piston as can be seen in FIG. 10 and 12. This tapping ejects each trapped air surrounding the superabsorbent polymer material (SAP) trapped under the piston and ensures that the liquid present wettably wet the surface of the SAP. In this arrangement, the motor 128 drives a shaft that provides the stroke of the connecting rod 130 between its upper and lower dead center. At the lower end of the connecting rod 130 is a rubber foot 132 having a diameter of 13 mm and which is shown in FIG. 12. The connecting rod stroke is 3 cm and performs a complete stroke cycle between upper and lower dead center every 0.7 seconds. The maximum pressure exerted by the disk piston on the SAP is 0.16 psi (0.11 kPa). ·

The fixture 134 shown in FIG. 10, provided with a vacuum channel 136 that allows the suction of interstitially absorbed liquid from the test sample to be performed. The vacuum channel is adapted to the base of the cylinder assembly. After placing the cylinder assembly containing the test specimen in

121

000 0000

0 ·

000 0

0 0 0 0 · 0 0

00

0 0 0 0 0 0 0 0 0 0 0 00 The clamping jig 134 sucks in the free, non-absorbent liquid between the superabsorbent material particles of the test sample. A suitable pump for this purpose is a suction pump 138, which is applied to the test sample by a vacuum of 100 torr (13.3 kPa) or less.

In FIG. 10 shows a completely arranged test apparatus. It should be noted here that the electronic timing device 140 is preferably used to control and control the duration of action of the tapping and vacuum devices. In this particular arrangement, the tapping device is mounted on the slide 142 to allow the device to be moved between a plurality of test specimens stored in the test apparatus.

Testing procedure

1. Preparation of a superabsorbent polymeric material by sieving it on a standardized sieve test assembly to provide a minimum amount of 0.160 grams of this particulate material that falls through a # 30 mesh sieve and is retained on a # 50 mesh sieve.

2. Weigh an amount of 0.160 grams (to within ± 0.001 grams) by sieving in step 1 the obtained superabsorbent material using weighing paper.

3. Slowly pour the weighed amount of superabsorbent material into a 100 mesh sieve cylinder. During pouring, any contact of the superabsorbent material with the cylinder walls must be avoided, as far as possible

122 adherence of particles of material to these walls. F ef ef ef ef ef ef ef ef ef ul ul ul ul částic ul After pouring the absorbent material, a slight shaking of the roll is carried out until the particles of material are evenly distributed on the screen.

4. Placing the plastic piston in the cylinder. Weigh the assembled cylinder assembly and record the measured weight as the weight of the superabsorbent material including the cylinder assembly.

5. Fill the physiological saline reservoir with blood saline to a height of 1 cm.

6. Placing the cylinder assembly in the saline containing reservoir so that it is directly below the connecting rod of the tapping mechanism and starting the electronic timing device. Starting the tapping device and tapping for a period of 8 seconds.

7. Placing a weight of 100 grams on top of the cylinder assembly disk piston at a time interval of 5 seconds after the 8 second tapping time period as shown in FIG. 11.

8. Removal of the cylinder assembly after 200 minutes of storage from the receptacle, weighing of the assembly and its subsequent placement, including a 100 gram weight, into the vacuum fixture, as shown in FIG. 13. Applying vacuum to the cylinder assembly for a period of 6 seconds.

9. Remove 100 grams of weight from the cylinder assembly, weigh the cylinder assembly without the weights, and record the measured weight.

123 • ···

0 0 0 0 0 •• 0 0000 ·· 00

Test results and analysis

Calculation of the amount of saline absorbed in grams per gram of superabsorbent polymer material for each test sample. The result is the Modified Load Absorption Absorption (MAUL) value of the superabsorbent material.

Zero Load Inundation Capacity (FAUZL)

Set goal

This test is designed to measure the uptake rate of physiological saline solution by superabsorbent polymer material (SAP) in particulate form. The test is used to measure the amount of saline as a function of time absorbed by 0.160 grams of superabsorbent polymer material (which is either dry or pre-saturated at the start of measurement) distributed over an area of 5.07 cm ² and subjected to a pressure of 0.01 psi (0.069 kPa). Based on the observed absorbency over time, the time characteristic (Tau) is determined to reach 60% of the balanced absorption capacity.

Used equipment and materials

Electronic scales with an accuracy of 0.001 grams (minimum load capacity 200 grams).

Cylinder assembly: a plastic cylinder 120 having an internal diameter of 1 inch (25.4 mm) provided with a 100 mesh stainless steel mesh attached to the bottom of the cylinder; plastic

124 • ··· Disc piston 122 weighing 4.4 grams and 0.995 inch (25.27 mm) in diameter. The diameter of the disc piston is 0.005 inch (0.13 mm) smaller than the inner diameter of the cylinder.

0.9% sodium chloride (NaCl) solution in blood saline.

Saline reservoir.

An electronic timer 140 capable of reading and reading for 200 minutes at 1 second intervals.

Weighing paper.

A tapping device arranged above the test sample and intended to ensure adequate and consistent tapping on the plate piston as can be seen in FIG. 10 and 12. This tapping ejects each trapped air surrounding the superabsorbent polymer material (SAP) trapped under the piston and ensures that the liquid present wettably wet the surface of the SAP. In this arrangement, the motor 128 drives a shaft that provides the stroke of the connecting rod 130 between its upper and lower dead center. At the lower end of the connecting rod 130 is a rubber foot 132 having a diameter of 13 mm and which is shown in FIG. 12. The connecting rod stroke is 3 cm and performs a complete stroke cycle between upper and lower dead center every 0.7 seconds. The maximum pressure exerted by the disk piston on the SAP is 0.16 psi (0.11 kPa).

The fixture 134 shown in FIG. 10, provided with a vacuum channel 136 that allows the suction of interstitially absorbed liquid from the test sample to be performed. The vacuum channel is adapted to the base of the cylinder assembly. After placing the cylinder assembly containing the test specimen in the fixture 134, the free, non-absorbed liquid between the particles of superabsorbent material of the test specimen is aspirated. A suitable pump for this

125 • fe fefe fefe fefe ·· • fe · fefefe * fe fe · fefefe fefefe fe fefe «• fe * ·« fefefe fefe fe • fefefe fefefe * fefefe ·· «« * · · <

the purpose is a suction pump 138 which acts on a test sample with a vacuum of 100 torches (13.3 kPa) or less.

In FIG. 10 shows a completely arranged test apparatus. It should be noted here that the electronic timing device 140 is preferably used to control and control the duration of action of the tapping and vacuum devices. In this particular embodiment it is. a tapping device mounted on the slide 142 that allows the device to be moved between a plurality of test specimens stored in the test apparatus.

Testing procedure

1. Weigh a quantity of 0.160 grams (to within ± 0.001 grams) by sieving in step 1 the obtained superabsorbent material using binding paper.

2. Slowly pour the weighed amount of superabsorbent material into a 100 mesh sieve cylinder. During pouring, any contact of the superabsorbent material with the cylinder walls must be avoided due to the possible adhesion of material particles to these walls. After pouring the absorbent material, a slight shaking of the roll is carried out until the particles of material are evenly distributed on the screen.

3. Placing the plastic piston in the cylinder. Weigh the assembled cylinder assembly and record the measured weight as the weight of the superabsorbent material including the cylinder assembly.

4. Filling the saline reservoir with blood e ·

126 • a

0 0 0 0 · 0 0 ·

0 00 00 000 00 • 0000 0000 000 0000 00 · 0 0 0 fyzi fyzi fyzi fyzi fyzi fyzi fyzi fyzi

5. Placing the cylinder assembly in the saline containing reservoir so that it is directly below the connecting rod of the tapping mechanism and starting the electronic timing device. Starting the tapping device and tapping for a period of 8 seconds.

6. Remove the drum assembly after the duration has expired

5 minutes from equipment and preparation, after time its storage from the reservoir, stop timing placing the cylinder assembly in a vacuum clamp see FIG. 14. Applying vacuum to the cylinder assembly period 6 seconds. 7.- Weighing cylinder assemblies; and recording measured weight. 8. Restoration cylinder assemblies back to reservoirs

with saline and placed under the tapping device and restarted by the timer. It should be noted here that the time interval between removing the cylinder assembly from the saline container in step 6 and reinserting it in the saline solution in step 8 must not exceed 30 seconds. Repeat the first, initial series of test tests, i.e., soaking the test sample, removing it from saline, subjecting it to negative pressure, and weighing it to collect and record the data as the soak time increases 1, 5, 10, 15, 30, 45,

60, 75, 90 and 120 minutes.

9. The testing procedure described in steps 1 to 8 is performed three times in total.

127 to this to this to this to this to to * * ····

Test results and analysis

Calculation of the amount of saline absorbed in grams per gram of superabsorbent polymer material, and evaluation of the measured amount as a function of increasing wetting time.

Determining the Resulting Balanced Absorption Capacity of Superabsorbent Polymeric Material (SAP): If this capacity varies less than 5% of the average SAP capacity obtained after 90 and 120 min (the average calculated from the measured values of all three tests), then it is the balanced equilibrium absorption capacity , or zero-load inundation capacity (FAUZL) uses the capacity measured after 120 min. If this capacity varies by more than 5% of the average capacity, it is necessary to repeat and include testing of the test sample and to supplement this testing by measuring the amount of saline absorbed at a soak time of 200 min. In this case, the measured capacity after 200 min is used as the balanced absorption capacity, or FAUZL.

Determination of the Time Characteristics (Tau) to achieve 60% Balanced Absorption Capacity by interpolation: This is done by calculating the capacity at 60% of its Balanced Value, while estimating the corresponding time interval necessary to achieve this capacity using a diagram. The interpolated time characteristic to reach 60% of the capacity (using the described procedure) is obtained by performing linear interpolation using measured data located on both sides of the predetermined time interval.

- 128 ······················

Calculation of the arithmetic mean of the interpolated time characteristic to achieve 60% of the balanced capacity (average of three test tests). This average time characteristic value is referred to as the value of Tau (τ).

Wetting angle of fibrous material

A suitable and suitable method for measuring the wetting angle of a fibrous material with a liquid is described in detail in U.S. Pat. No. 5,364,382, the entire disclosure of which is hereby incorporated by reference in its entirety. The measurement of the wetting angle of the fibrous material by the liquid is particularly useful for determining and evaluating the wettability of the fibrous materials. A repeated cycle of measurement of the wetting angle of the individual fibers of the fibrous material under the influence of distilled water can be performed using the Cahn SFA-222 Analyzer and WET-TEK software for evaluating the measured data. The Cahn SFA-222 Analyzer is marketed by Cahn Instrumets, Inc., located in Cerritos, California, and WET-TEK software by Biomaterials International, Inc., located in Salt Lake City, Utah. The fibrous materials are subjected to testing in three cycles and the distilled water bath changes between the first and second cycles. The resulting wetting angle of the fibrous material is determined from the arithmetic mean of the measured data over three measurement cycles. The test apparatus shall be operated in accordance with the standardized operating procedure described in the manufacturer's manual.

Examples

The following examples are given for purposes of

129

9 ··· «·· ···· 0 0 0 0 0 0 * 0 0 000 000 0 0 9 9 9 9

The present invention is not to be construed as limiting the scope of the invention in any way. In the context of the examples, it should be noted in various cases that the first primary layer portion 48 may alternatively be referred to as the top or top layer, while the second primary layer portion 50 may alternatively be referred to as the lower or lower layer.

Example 1.

The wearer-facing absorbent layer has a basis weight of 500 g / cm ² and consists of 50% of the Dow 53C superabsorbent material marketed by Dow Chemical and 50% of the HPF2 type mercerized pulp marketed by Buckeye Corp. The Dow 53C superabsorbent material exhibits: τ value of 8.5 min; an FAUZL inundation capacity value of 33 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 26.2 g / g. This absorbent layer facing the skin of the wearer extends, as can be seen in FIG. 3 and 3A, in the region of the layer portion 48, and is densified to a value of 0.2 g / cm ³ .

The garment-facing absorbent layer has a basis weight of 200 g / cm ² over the area covered by the absorbent layer 48 facing the wearer &apos; s skin, and the remainder of its total extent coincides with the total extent of the absorbent core defined by its shape. configuration (region of the layer portion 50), the basis weight of the layer consists of 25% superabsorbent

SXM 880, marketed by Stockhausen, and 75% wood pulp in the form of fluff fluff type CR-1654, marketed by Alliance Forest Product, based

500 g / cm ² . material

This type

130 • 00 · · 0 0 * 0 0 0 0 00000 0 000 0 0 00 0 0 0 0 0 00 * 0 0 0 0 0 0 0000

000 0000 0 «0 · ·· 0« by Coosa Pines, Alabama. SXM 880 superabsorbent material exhibits: τ 4 min; a FAUZL inundation capacity value of 38 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 29.8 g / g. This absorbent layer facing the wearer's garment extends completely, as can be seen in FIG. 3, over the entire extent of the absorbent system (area of the layer portion 50) and is densified to a value of 0.2 g / cm ³ .

This exemplary embodiment has a flow conductivity value of 3.24 x 10 ^-6 cm ^-3 and a liquid wicking value of 38.3%.

In this exemplary embodiment, either or both of the absorbent layers may be stabilized by cross-linking using a crosslinking agent such as Kymene.

Example 2

The wearer-facing absorbent layer has a basis weight of 336 g / cm ² and consists of 75% of Dow 53C type superabsorbent material available from Dow Chemical and 25% of HPF2 type mercerized pulp available from Buckeye Corp. The Dow 53C superabsorbent material exhibits: τ value of 8.5 min; Inundation capacity value. FAUZL 33 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 26.2 g / g. This absorbent layer facing the skin of the wearer extends, as can be seen in FIG. 3 and 3A, in the region of the layer portion 48, and is densified to a value of 0.2 g / cm ³ .

The garment facing the wearer has an absorbent layer

131 »00

342 g / cm ² . material

This type, in the area covered by the absorbent layer 48 facing the wearer's skin, has a basis weight of 300 g / cm ² and the remainder of its total extent coincides with the total extent of the absorbent core defined by its shape configuration (layer area area) 50), showing a basis weight layer consisting of 20% superabsorbent

SXM 8 80, marketed by Stockhausen, and 80% wood pulp in the form of fibrous fluff type CR-1654, marketed by Alliance Forest Product, located in Coosa Pines, Alabama. SXM 880 superabsorbent material exhibits: τ 4 min; a FAUZL inundation capacity value of 38 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 29.8 g / g. This absorbent layer facing the wearer's garment extends completely, as can be seen in FIG. 3, over the entire extent of the absorbent system (region of the layer portion 50), and is densified

0.2 g / cm ³ .

This exemplary embodiment has a flow conductivity of 4.13.10 &quot; 6 cm &lt; ³ &gt; and a liquid absorption value of 31.6%.

Example 3

The wearer-facing absorbent layer has a basis weight of 502 g / cm ² and consists of 60% of the Dow 53C superabsorbent material marketed by Dow Chemical and 40% of the HPF2 mercerized pulp marketed by Buckeye Corp. The Dow 53C superabsorbent material exhibits: τ value of 8.5 min; an FAUZL inundation capacity value of 33 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 26.2 g / g. This absorbent

132

The 99999 layer facing the skin of the wearer extends as can be seen in FIG. 3 and 3A, in the region of the layer portion 48, and is densified to a value of 0.2 g / cm ³ .

The garment-facing absorbent layer has a basis weight of 200 g / cm ² in the area covered by the absorbent layer 48 facing the wearer &apos; s skin and the remainder of the total range defined by the absorbent core (layer area 50). )

435 g / cm ² . This cover type material with an overall range of its shape configuration exhibits a basis weight layer consisting of 25% superabsorbent SXM 880, marketed by

Stockhausen, and 75% wood pulp in the form of fluff CR-1654, available from Alliance Forest Product, located in Coosa Pines, Alabama. SXM 880 type superabsorbent material exhibits: τ 4 min; FAUZL inundation capacity value of 38 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 29.8 g / g. This absorbent layer facing the wearer's garment extends completely, as can be seen in FIG. 3, over the entire extent of the absorbent system (area of the layer portion 50) and is densified to a value of 0.2 g / cm ³ .

This embodiment exhibited a flow conductivity 4,99.10 ^- 6 cm "3 and a liquid absorption of 31%.

The above values are summarized in the following table:

Example

Value

Value

Comb. Value

133 • · · · ·

111 9 19 1118

1 191 191 1111

1 · 1 9 1 119 9 1 · • fefefe fefefe • • «• fefefe ·· fefe · · 11

# flow conductivity [.10 “ ⁶ cm ² ] absorbability liquid [%] conductivity / / water absorption [.10 ^-δ cm ² ] 1 3.24 38, 3 16.0 2 4.13 31, 6 14.7 3 4.99 31, 0 15.3

Functional application of some commonly used absorbent structures is associated with the need for improved distribution of the acting fluid, while other commonly used absorbent structures require functional absorption of the acting fluid during functional application. Unfortunately, such commonly used absorbent structures are not designed to be capable of providing a combination of said properties, i. both improved aspiration and improved distribution, but which are typically provided by the absorbent structure according to various embodiments and aspects of the present invention. For comparison purposes, Comparative Examples 4 to 8, as shown in the following table, were prepared:

At- klad # Upper layer SAP SAP BW Upper layer pulp type Pulp BW Bottom layer SAP SAP BW Bottom layer pulp type Pulp BW 4 ^A SXM 880 CR-1654 SXM 880 CR-1654 215 [g / cm ² ] 400 [g / cm ² ] 78 [g / cm ² ] 232 [g / cm ² ] 5 ^A 20/30 SXM 870 CCLC 60/100 SXM 870 CCLC 269 [g / cm ² ] 292 [g / cm ² ] 529 [g / cm ² ] 294 [g / cm ² ] 6 ^a SXM 870 CCLC 60/100 SXM 870 CCLC 159 [g / cm ² ] 295 [g / cm ² ] 319 [g / cm ² ] 295 [g / cm ² ] ₇ a 20/30 SXM 870 CCLC 60/100 SXM 870 CCLC 215 [g / cm ² ] 281 [g / cm ² ] 239 [g / cm ² ] 281 [g / cm ² ] 8 ^A ON CCLC SXM 880 CR-1654

134 • 4 · 4 4 * 4 · * 4 4 • 9 9

4 44 4 4 4 4 4 4

4444 4444 4444 4444 44 44 44

[g / cm ² ]

250 [g / cm ² ]

A - As Example 4, a characteristic embodiment of the absorbent structure described in U.S. Patent No. 5,356,403 to Faulks et al. In this example, the upper layer has a density of 0.2 g / cm ³ and the lower layer has a density of 0.3 g / cm ³ .

B - Examples 5 to 7 show characteristic embodiments of the absorbent structures described in EP 0 631 768 A1 to Plischke et al. In these examples, both layers have a density of 0.2 g / cm ³ and both layers extend over the entire range of the composite absorbent core defined by its shape configuration and described in said patent document.

C - As Example 8, a characteristic embodiment of the absorbent structure described in US Patent No. 5,360,420 to Cook et al. In this example, the topsheet has a density of 0.07 g / cm ³ and the backsheet has a density of 0.25 g / cm ³ . The shape configuration of both layers is described in detail in said document.

CCLC is chemically cross-linked cellulose, as described, for example, in U.S. Pat. 4,898,642.

SXM 870 and SXM 880 are superabsorbent materials available from Stockhausen under the tradename FAVOR SX. Their designation, if any, means that they are screened to the desired particle size by sieving, for example: 20/30 mesh (600 to 850 μιη), 60/100 mesh (150 to 250 μιη).

~ 135 · 0 0 0 0 0 0 0 0 0 0 00 00 0 0 0 0. 0 · 0 0 0000 • 00 0000 00

The superabsorbent material SXM 880 has a τ of 4 min; a FAUZL inundation capacity value of 38 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 29.8 g / g.

The superabsorbent material SXM 870 has a τ of 4 min; a FAUZL inundation capacity value of 32.5 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 27 g / g.

The 20/30 SXM 870 superabsorbent material has a τ of 6.4 min; a FAUZL inundation capacity value of 34 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 28.8 g / g.

The 60/100 SXM 870 superabsorbent material exhibits a τ of 3.3 min; a FAUZL inundation capacity value of 27.5 g / g; and a MAUL absorption value at a load of 0.3 psi (2.07 kPa) of 23.3 g / g.

The characteristic values exhibited by the absorbent structures of Examples 4 to 8 are shown in the following table:

Example Flow conductivity t.10 ^-6 cm ² ] Value absorbability liquid (%) Comb. conductivity / / water absorption [.10 ~ ⁶ cm ² ] 4 2.9 31.7 13, 5 5 6.75 13.3 11.2 6 6, 75 13, 4 11.2 7 6, 68 20, 8 13, 6 8 1.4 35, 2 13, 1

136 • fefe • fefe • fefe • fefe · fe · fefe · fe fefe fe fefe fefe fefe fefe

As can be seen from the above, neither absorbent structure of the Comparative Examples can provide a combination of desirable characteristics provided by the absorbent structure of the present invention.

From the foregoing detailed description of individual specific embodiments of the present invention, it will be apparent to those skilled in the art that various modifications and modifications may be made thereto without departing from the spirit of the invention, all such variations and modifications being made thereto; modifications that fall within the scope of the present invention as defined in the appended claims.

Claims (24)

An absorbent article comprising: a backsheet; substantially liquid-permeable topsheet; a composite absorbent structure sandwiched between said backsheet and topsheet layers, the composite absorbent structure comprising an absorbent core having a first primary layer portion and a second primary layer portion, the second primary layer portion exhibiting an uneven, selectively distributed zonal basis weight ; and at least one of said first and second primary sheet portions has a liquid wicking value of at least about 36%. The absorbent article of claim 1, wherein the absorbent core has a dry-state thickness of no more than about 6 mm and a minimum crotch region width of no more than about 10 cm. The absorbent article of claim 1, wherein the absorbent article is user-configured for adults; and that the absorbent core has a dry-state thickness of not more than about 6 mm and a minimum crotch region width of not more than about 14 cm. 4. An absorbent article according to claim 1 wherein the absorbent core has a combined conductivity / absorbency value of at least about 14 · 10 ^{-4 * 6} cm ³ . • · • ··· 138 5. The absorbent article of claim 1 wherein the absorbent core has a dry-state thickness of no more than about 6 mm and a minimum crotch region width of no more than about 10 cm. The absorbent article of claim 1, wherein the first primary layer layer is disposed on the skin facing the user side of the composite absorbent structure, and the second primary layer portion is disposed outside of the first primary layer portion. 7. An absorbent article according to claim 1 wherein at least one of the primary sheet portions comprises a superabsorbent material having a modified absorbency absorption value at a load of at least about 20 g / g. The absorbent article of claim 1, wherein at least one of the primary sheet portions comprises a superabsorbent material having a Tau value of less than about 0.8 min. 9. An absorbent article comprising an absorbent core having a first primary layer portion and at least a second primary layer portion, wherein the absorbent core has a length in the longitudinal direction, a width in the transverse direction, and a predetermined upstream end edge; wherein the first primary layer portion has a basis weight of not less than about 100 g / m ² and which is not 0 0 139 00 00 0 000 0000 0 0 0 0 000 0 0 0 0 0 0 00 00 000 00 0 0 0 0000 000 »000 0000 00 00 0 · 00 greater than about 700 g / m ² ; that the first primary layer layer has a density of not less than about 0.03 g / m ³ and not greater than about 0.4 g / m ³ ; wherein the first primary layer portion comprises fibrous material in an amount of not less than about 25 wt% and not more than about 80 wt%; that the fibrous material comprises fibers having a diameter of not less than about 4 µm and not more than about 20 µm; wherein the first primary layer layer comprises superabsorbent material in an amount of not less than about 50 wt% and not more than about 80 wt%; that the superabsorbent material comprises particles having a size of not less than about 110 µm and not more than about 1000 µm; that the superabsorbent material exhibits a modified absorbency absorption at a MAUL load of not less than about 20 g / g; and that the superabsorbent material has a Tau value of less than about 0.8 min. 10. An absorbent article according to claim 9 wherein the first primary layer portion is substantially adjacent each other to the side end edges of the second primary layer portion; and that the first primary layer portion is disposed in a zone that begins with a transverse extending line spaced about 7% of the total length of the absorbent core inwardly from the foremost end edge of the absorbent core and extends to the second transverse extending line spaced about 62% the total length of the absorbent core 140 • fefe • fe fe * • fe • fe • fefe · fe • fe • fe • « • · • • fefefe fe • • « fe fe • • • · fe • • « fefefe fefefefe • · • · fe fe • fe inwardly from said foremost end edge of the absorbent core. The absorbent article of claim 10, wherein the first primary layer portion comprises a binder material. An absorbent article according to claim 9, wherein the first primary layer portion comprises a plurality of partial layers. The absorbent article of claim 9, wherein the second primary sheet portion has a longitudinal extent that is greater than the length of the first primary sheet portion in the longitudinal direction; and that the second primary layer portion has a transverse direction range that substantially borders the extent of the first primary layer portion in a transverse direction. The absorbent article of claim 9, wherein the second primary sheet portion has a longitudinal extent that is greater than the length of the first primary sheet portion in the longitudinal direction; that the second primary layer portion has a transverse direction range that is smaller than the first primary layer portion in a transverse direction; and that the extent of at least a portion of the second primary sheet portion in the transverse direction is not less than about 30% of the extent of the corresponding portion of the first primary sheet portion in the transverse direction. An absorbent article according to claim 9, wherein the second primary layer portion has a range - 141 • 44 ·· 4 4 4 4 4 · 4 4 4 4 4 4 4 444 44 4 44 44 44 44 44 4 4444 4444 444 4444 44 44 44 44 in a longitudinal direction that is greater than the extent of the first primary layer portion in the longitudinal direction; that the second primary layer portion has a transverse direction range that is greater than the first primary layer portion in a transverse direction; and that the extent of at least a portion of the first primary sheet layer in the transverse direction is not less than about 30% of the extent corresponding to an adjacent portion of the second primary sheet layer in the transverse direction. An absorbent article according to claim 9, wherein the receiving zone of the second primary sheet layer has a basis weight that is less than the basis weight remaining to receive an unspecified portion of the second primary sheet layer. 17. The absorbent article of claim 9, wherein the receiving zone of the second primary sheet layer has a basis weight of not less than about 100 g / m ² and not more than about 250 g / m ² ; and wherein the unrecognized portion of the second primary layer portion has a basis weight of not less than about g / m ² and not greater than about 550 g / m ² . The absorbent article of claim 17, wherein the second primary layer layer has a density of not less than about 0.1 g / m ² and not greater than about 0.3 g / m ² ; wherein the second primary layer portion comprises fibrous material in an amount of not less than about 50 wt% and not more than about 95 wt%; that the fibrous material comprises fibers having the following characteristics: 142 • 0 • 0 0 0 0000 0000 • 00 0000 00 00 00 00 a diameter of not less than about 4 µm and not more than about 20 µm; that the fibrous material comprises fibers having a water-wetting angle of not more than about 70 degrees; wherein the second primary layer layer comprises superabsorbent material in an amount of not less than about 5 wt% and not more than about 50 wt%; and that the superabsorbent material comprises particles having a dry particle size of not less than about 110 µm and not more than about 1000 µm. 19. An absorbent article according to claim 18 wherein the superabsorbent material contained in the second primary sheet has a modified absorbency absorption under a MAUL load of not less than about 20 g / g and a Tau time value of at least about 0.4. minutes. 20. An absorbent article according to claim 19 wherein the superabsorbent material contained in the second primary sheet layer is configured as a layer sandwiched between the paper layers. 21. The absorbent article of claim 20, further comprising a backsheet and a substantially liquid-permeable topsheet configured so that the absorbent core is sandwiched between the layers. 22. The absorbent article of Claim 21 wherein the absorbent core has a flow conductivity of at least about 7 · 10 ^-6 cm ³ ; and 44 00 143 • 00 00 • 44 * 4 44 0 944 000 0 0 0 0 0 0 4 4 4 4 4 No. 944,494,444 that at least one of said first and second primary layer portions has a liquid wicking value of at least about 16%. 23. The absorbent article of Claim 22 wherein at least one of said first and second primary sheet portions has a liquid wicking value of at least about 36%. 24. The absorbent article of claim 22, wherein the second primary layer portion comprises a binder material.