MXPA00003383A

MXPA00003383A - Layered absorbent structure with zoned basis weight and heterogeneous layer region

Info

Publication number: MXPA00003383A
Authority: MX
Inventors: Stanley Michael Gryskiewicz; Violet May Grube; David Louis Zenker; Richard Norris Ii Dodge; Thomas Gerald Bolwerk; Shannon Kathleen Melius; Xiaomin Zhang; Sridhar Ranganathan; Rob David Everett; Sylvia Bandy Little; Debra Jean Mcdowall; Lawrence Howell Sawyer; Billie Jean Matthews; Yong Li
Original assignee: Kimberly Clark Co
Priority date: 1997-10-08
Filing date: 2000-04-06
Publication date: 2000-11-01
Also published as: MX225083B; WO1999017679A3; EP1018981A2; IL134972A0; BR9815392A; WO1999017679A2; JP2002509737A; AR017306A1; AU1360399A; AU738839B2; KR20010015721A; CA2304219A1; CO5070597A1

Abstract

A distinctive absorbent article includes an absorbent core having multiple absorbent layers, wherein the absorbent layers interact in a manner such that it preferably locates the liquid absorbed in a designated high saturation transmission layer. The location of the liquid within the transmission layer increases the potential of this layer to move the liquid through capillary action due to the higher saturation level in the incremental amount of the available liquid. The ability to take the absorbent system is maintained or improved on current systems by maintaining a second layer of the absorbent system at low saturation levels through as many product discharges as possible, while providing optimum throughput of proper control of composite properties. The low saturation in this layer provides a hollow volume for the incoming discharge as well, as a high permeability, thus increasing the intake rate of the absorbent system as a whole, but the structure of the low saturation layer is also balanced to provide a level Highly adequate capillary tension to provide sufficient control of the liquid to prevent runoff from occurring. This low saturation layer is used in addition to an emergence material and provides a shooting functionality in addition to that provided by the emergence material. In particular aspects of the invention, the body-to-body layer the absorbent core does not extend over the entire surface of the complete absorbent core, therefore it is not used as the high saturation transmission layer, but as the take-up layer. This arrangement also allows the layer taking to be in direct contact with the incoming liquid, thus allowing more immediate access and an improved take-up function. In additional aspects, at least one primary layer region may have a non-uniformly zoned, selectively weighted base distribution. Particular configurations of at least one primary layer region may be constructed with a target area of such a primary layer region having a basis weight which is less than a weight of another non-target part of the primary layer region. In addition, at least one primary layer region can have a heterogeneous structure. In particular constructions, the at least one primary layer region may include a plurality of two or more subcaps

Description

ABSORBENT STRUCTURE IN LAYERS WITH A ZONED BASE WEIGHT AND A HETEROGENIC LAYER REGION Field of the Invention The present invention relates to a layered absorbent structure. More particularly, the invention relates to an absorbent structure composed of layers in individual layers which are constructed and arranged to selectively cooperate to provide the desired performance parameters in the composite, layered structure.

Background of the Invention The operating objectives of disposable absorbent articles, such as infant diapers, include non-draining of the product, dry feel for the user, and a comfortable fit throughout the life of the product. Thus, the absorbent articles typically contain an absorbent matrix to provide liquid handling and other absorbent functions required to meet the performance objectives of the product. The absorbent matrix of the absorbent articles is commonly composed of wood pulp fibers, and the superabsorbent material is frequently distributed in the absorbent matrix to improve the absorbent capacity of the liquid. The absorbent matrix is usually formed in an hourglass shape, in a T-shape, or in a similar configuration with a reduced absorbent width in the mid-leg region for comfort adjustment for the user.

The absorbent articles often drain before the absorbent capacity of the entire absorbent core liquid has been fully utilized. A problem that results in runoff is the lack of capacity of the absorbent matrix to completely take liquids quickly and completely when large amounts of liquid are discharged into the absorbent article. Another associated problem contributing to runoff is the lack of ability of the absorbent core to move or distribute sufficient quantities of liquid between discharges from a target area portion of the absorbent article to more remote and more distant end regions of the absorbent matrix than They have not been used. This results in the satisfaction of only the central target area of the absorbent core and in an excessive thickness, bulging and bagging of the heavy wet absorbent material which results in a poor working and notching of the product and in a discomfort of the user. These deficiencies of the absorbent core are especially acute for the narrower crotch absorbent designs having a crotch width of less than about 4 inches that provides less absorbent mass and "volume in the target area for the improved product notch.

The absorbent matrix of the current absorbent articles does not adequately fulfill the current operating objectives. The desirable liquid absorption and distribution functions for the absorbent matrix required by the absorbent article designs of superior crotch-up efficiency are beyond the current capabilities. Consequently, there is a need for absorbent structures which can provide a fluid acquisition improves liquid discharges and an improved liquid distribution to move liquid out of the target area between liquid discharges to maintain desirable liquid intake behavior during the life of the product.

Brief Description of the Invention The invention described is an absorbent system which includes multiple absorbent layer regions. Two or more absorbent layer regions can advantageously interact in a shape which preferentially locates a designated liquid in a selected layer region. This location of liquid within the layer region can increase the potential of this layer region to move the liquid through a capillary action due to the higher saturation level and a quantity increased liquid available. The intake capacity of the absorbent system can be maintained or improved with the current systems by maintaining a second region of the absorbent system layer at low saturation levels through as many product discharges as possible, while providing optimum intake performance through u appropriate control of the composite properties. The low saturation in this layer region provides a hollow volume and for the incoming discharge as well as a higher permeability thereby increasing the acquisition or intake rate of the absorbent system as a whole. The properties of this cap region can advantageously be balanced with a suitably higher level of capillary tension to provide a sufficient control of liquid to essentially stop unwanted run-off. This region of low saturation layer can be used in addition to a layer of emergence handling material and can provide a take-up function in addition to that provided by the emergence material. In particular aspects of the invention, a body-to-body layer of the absorbent structure may not extend over the entire surface of the absorbent system, and may be configured to provide a portion of the acquisition layer which is additional to the transmission layer region of the absorbent structure. high saturation. This arrangement can locate the intake layer region for this essentially in direct contact with the incoming liquid, thus allowing more immediate access to the incoming liquid an improved liquid intake function.

In additional aspects, at least one primary layer region may have a selectively zoned and non-uniform basis weight distribution. Particular configurations of at least one primary layer region may be constructed with a target area of the primary layer region having a basis weight which is less than the basis weight of another non-target part of the region of primary layer. In addition, at least one primary layer region can have a heterogeneous structure. In particular configurations, at least one primary layer region may include a plurality of two or more layers.

In other aspects of the invention, the layer regions of the absorbent system can cooperate to provide a desired Liquid Transmission Potential Value, such as a Liquid Transmission Value of at least a minimum of about 16 percent. The invention may also provide a desired Flow Conductance Value, such as a Flow Conductance Value of at least about 7 * 10"6 cm 3. In additional aspects, the invention may provide a Combined Transmission-Conductance Value. of at least about 14 * 10"6 cm3. Additional aspects of the invention can provide a system the which provides the desired Flow Conductance Value also includes at least one layer region having the desired Liquid Transmission Potential value. Still other aspects of the invention may include a superabsorbent polymer material (SAP) which exhibits a particular controlled absorbency rate. For example, a desired controlled superabsorbent may exhibit a particular absorbency rate, Tau value, such as a Tau value of at least d about 0.67 minutes. In additional aspects, the invention may include a combination of superabsorbent materials which have a particular proportion of Tau values.

In various aspects, the present invention can provide an article having a more efficient absorbent structure which is thin with a low volume, has a high absorbent capacity, and is resistant to runoff. The configurations of the invention can more fully utilize the total potential absorbent capacity of the absorbent structure, and can more efficiently move and distribute the acquired liquid out from the original intake area to more remote areas which are located closer to the regions. of distal end of the absorbent structure. In addition, the structures of the invention can provide an ability to acquire and take the liquid at a rapid rate, they can maintain the desired intake rate after the The absorbent structure has been moistened and has reached a significant part of its potential total absorbent capacity.

Brief Description of the Drawings The invention will be more fully understood and the additional advantages will become more apparent when reference is made to the following detailed description of the invention and the drawings in which: Figure 1 representatively shows a top view of an absorbent article which incorporates an absorbent system of the invention.

Fig. IA representatively shows a side cross-sectional view of the article of Fig. 1.

Figure IB representatively shows a longitudinal cross-sectional view of the article of figure 1.

Figure 2 representatively shows a top view of the structure of an absorbent core of the invention having a first top layer region, which extends over a middle part of the total area of the absorbent core, and a second bottom layer region the which extends over essentially the entire area of the absorbent core or matrix, in where the opposite longitudinal end edges of the first layer region are separated from each other from the opposite longitudinal end edges of the second layer region.

Figure 2A representatively shows a longitudinal cross-sectional view of the absorbent core of Figure 2.

Figure 3 is a top view of another absorbent matrix structure of the invention having a first top layer region which extends over a middle part of the total area of the absorbent core, and a second bottom layer region which extends over essentially the entire area of the absorbent core, wherein the second layer region has a non-uniform zoned base weight distribution with a relatively greater basis weight at its longitudinally opposite end portions to provide a reverse longitudinal zoning of the lower layer.

Figure 3A representatively shows a longitudinal cross-sectional view of the absorbent core of Figure 3, where a middle part is selected from the second layer region has a basis weight which is lower than that of the longitudinally opposite end portions. and adjacent to the second layer to provide an inverse zonifiable basis weight of the second layer in the target area.

Figure 4 representatively shows a top view of another absorbent core structure having a top layer region which covers a full front part of the bottom layer region, but covers less than the entire back part of the bottom layer region .

Figure 4A representatively shows a longitudinal cross-sectional view of the absorbent core of Figure 4.

Figure 5 is a top view of another absorbent matrix structure having a top layer region which completely covers a bottom layer region.

Figure 5A representatively shows a longitudinal cross-sectional view of the absorbent core of Figure 5.

Fig. 6 representatively shows a top view of another absorbent core with an upper layer region which both have a smaller narrower side dimension and a shorter shorter longitudinal dimension than the lower layer region.

Figure 7 representatively shows a longitudinal cross-sectional view of an absorbent core of the invention which includes a lower layer region comprised of a laminate having superabsorbent particles placed in sandwich form and held between the liquid permeable layer layer regions.

Figure 8 representatively shows a longitudinal cross section of another absorbent core of the invention which includes a second bottom layer region composed of a plurality of heterogeneous sublayer laminates arranged to provide a non-uniform zoned base weight within the region of background layer.

Figure 9 representatively shows a longitudinal cross-sectional view of another absorbent core of the invention which includes a bottom layer region composed of a heterogeneous laminate wherein the distribution of the superabsorbent material is arranged to provide a non-uniform zoned base weight of superabsorbent within the background layer region.

Figure 10 shows a schematic representation of a test apparatus for determining the particular properties of a superabsorbent material.

Figure 11 shows a cross-sectional view representative of a group of cylinders placed in a basin with a weight applied to the piston disk.

Figure 12 shows a representative cross-sectional view of a cylinder group placed in a basin with a piston rod placed to strike against a piston disk.

Figure 13 shows a representative cross-sectional view of a cylinder group with a weight applied to the piston disk, and placed on a vacuum accessory.

Figure 14 shows a representative cross-sectional view of a cylinder group placed on a vacuum fitting.

Detailed description of the invention The various aspects and embodiments of the invention will be described in the context of a disposable absorbent article, such as a disposable diaper. It will, however, be readily apparent that the present invention can also be used with other articles, such as the underpants of learning for children; items for women's care, incontinent garments, protective cover pads and the like, which can be configured to be disposable. Typically, disposable articles such as disposable garments are intended for limited use and are not intended to be washed or otherwise cleaned for reuse. A disposable diaper, for example, is discarded after it has been soiled by the wearer. In the context of the present invention, a mechanical fastening system is a system which includes cooperating components which mechanically interengage to provide a desired securing.

The present invention provides an absorbent system having an absorbent core which includes multiple layer regions and can provide improved void volume, permeability and liquid intake performance in a designated target region. The absorbent system, particularly a part of the absorbent core of the system, can essentially regenerate the desired levels of void volume through the transport of liquid out of the target region, such as by transport or other mechanisms. The liquid can advantageously be concentrated in the layer region of the absorbent core which is designed to provide the desired relatively high liquid distribution, while the layer region designated to provide the hollow volume and the outlet may remain relatively low in saturation. In most cases the relative base weights or superabsorbent concentrations of the layer regions can be configured and arranged so that suitable cooperating materials with the appropriate properties will be able to work in the system and provide good operation. It has been found, however, that particular combinations can provide significant improved performance over others. It should be noted that the base weights of other properties of the components can be modified in specific areas of the absorbent structure (e.g. versus back-up) to optimize the cost, other attributes of the consumer, or to promote the desired distributions of the absorbed liquid.

In the present invention, the absorbent layer regions can be uniquely configured to interact cooperatively in a manner which preferentially locates the liquid in one or more designated or designed layer regions. This location of the liquid within a designated layer region can increase the potential of this layer region to move and distribute the liquid through capillary action due to the relatively high level of saturation and the increased amount of liquid available in the designated layer .

The intake capacity of the absorbent system, particularly the intake capacity of the absorbent core, can be maintained or improved on conventional systems by maintaining a primary tap layer region of the absorbent system at low saturation levels through as many product discharges as possible, by providing optimum take-up operation through proper control of the composite properties. The relatively low levels of liquid saturation in this intake layer region provides hollow volume for incoming discharge as well as higher permeability, thereby increasing the intake rate of the absorbent system as a whole. The tap layer region can be advantageously configured to provide an appropriately higher level of capillary tension to adequately control the movement of the liquid and essentially prevent undesired draining. This low saturation take-up region is desirably employed in addition to a separately provided emergence management layer or part, and can provide a take-up function which is additional to that provided by the emergence layer material.

In particular configurations, the take-up layer region may be located on the body side of the absorbent structure, and may be configured not to extend over the full-area extent of the overall overall absorbent structure. Therefore, the layer region from side to body Primary is used as a take-up layer region, and is not employed as the high saturation transport layer region. This arrangement also allows the intake layer region to be in an essentially direct contact with the incoming liquid, thereby allowing more immediate access to the incoming liquid and a more effective intake function.

The layer regions can be designed, individually or in combination, to provide an improved balance of intake and distribution functions, particularly the distribution and intake of aqueous liquids. Improved operation can, for example, be provided by modifying the physical and / or chemical composition of the component materials or by modifying the physical configurations of the components.

Current superabsorbent polymer and fiber (SAP) composites used in conventional designs of absorbent articles, such as diapers, can provide ordinary combinations of take-up, distribution and retention functions. However, there is still a continuing need for improved materials and improved structure systems that provide improved combinations having increased levels of picking, distribution and retention functions. In order to provide improved runoff resistance, the present invention incorporates improved materials wherein the Materials exhibit improved properties in at least one of the functional areas. As a result, the general operation of the system can be improved.

The take-off function may, for example, be adjusted by controlling factors such as the fiber and particle size of the materials in the relevant cap region, the porosity of the layer region, the basis weight of the layer region, and the layer region composition. The distribution or distribution function can, for example, be adjusted by controlling factors such as the particle and fiber sizes of the component materials, the contact angle provided by the materials, the liquid surface tensions provided by the liquid, and the base weight of the materials.

In order to further improve the desired balance of the absorbent properties, a number of important factors have been identified which may allow the layer regions to work better in combination, and thus provide improved overall system performance. Factors include a desired Flow Conductance Value and a Liquid Transmission Value provided by the absorbent system. An additional factor is a Transmission-Conductance Value provided by the system.

The Flow Conductance is a value which is based on the physical properties of the absorbent materials, particularly the absorbent materials which are placed in the target area of the absorbent system, and is related to the intake capacity provided by the structure of absorbent core. Desirably, the Flow Conductance Values have a minimum of no less than about 2.5 * 10"6 cm 3. Alternatively, the Flow Conductivity Value is not less than 3 * 10" 6 cm3, and optionally, is not less than 3.5 * 10"6 cm3 to provide improved performance In other additional aspects of the invention, the Flow Conductivity Value may be up to about 5 * 10" 6 cm3. Alternatively, the Flow Conductance Value can be up to about 7 * 10"6 cm3, and optionally, it can be up to about 9 * 10" 6 cm3, or larger to provide improved performance.

The Liquid Transmission Potential (or Liquid Transmission Value) value is an operating parameter which refers to the amount of fluid removed from the described target area of the absorbent structure during the vertical transport operation. This value represents the ability of the absorbent structure to remove the fluid from the target area area between discharges, and at least one layer region of the absorbent system is configured to provide the value of Transmission of desired liquid. In desired form, at least one layer of the absorbent system, particularly at least one primary layer region of the absorbent core, can provide a Liquid Transmission Value of not less than a minimum of about 10 percent. Alternatively, the Liquid Transmission Value is not less than about 15 percent and optionally is not less than about 20 percent. In additional aspects of the invention, the absorbent system can provide a Liquid Transmission Value of up to about 60 percent. Alternatively, the Liquid Transmission Value can be up to about 65 percent, and optionally, it can be up to about 70 percent or higher to provide additional improved performance.

The Combined Conductance Transport Value (C) of the system can be at least about 14 * 10'6 cm3. Alternatively, the Combined Transmission-Conductance Value may be at least about 17 * 10"d cm3, and optionally may be at least about 20 * 10" 6 cm3 to provide an improved performance balance. In other desired arrangements, the combined Transmission-Conductance value may be at least about 15 * 10"6 cm3, alternatively it may be at least about 16 * 10" 6 cm3, and optionally may be at least about 18 * 10"6 cm3 to provide the improved benefits.

O H I * In thin absorbent designs with narrow crotch sections, the target area of the product, in its dry state, ordinarily does not have sufficient void volume available to efficiently absorb the initial discharge of the liquid, such as urine. This lack of hollow volume can be compensated for by incorporating a superabsorbent polymer particularly configured in an amount sufficient to absorb the incoming liquid during the time of discharge. The built-in superabsorbent polymer is configured to acquire and retain the amount of fluid that is desired to be absorbed during discharge to provide the desired runoff resistance.

Although some of these parameters have been discussed individually in the past, it has remained difficult to provide an effective combination of these attributes within a single composite structure, while maintaining the desired consumer attributes. The difficulties encountered in the past have typically involved a desire to have a relatively low superabsorbent polymer content., either in full structure or within an individual layer, to improve transport capacity. Where the concentration of low superabsorbent polymer is used through the product, an excessively large product thickness may be required to provide the desired absorbent capacity. Attempts have been made to provide an absorbent layer with a concentration of low superabsorbent polymer to promote transport, while maintaining high superabsorbent polymer concentrations in another layer to achieve a thin product having the desired amount of absorbent capacity. Such systems have not provided the desired levels of operation because the liquid can preferably move to areas containing relatively higher concentrations of superabsorbent polymer. In the layer region containing a relatively low concentration of superabsorbent polymer, the amount of liquid remaining may be insufficient to provide the desired levels of transmission.

To overcome these disadvantages, a particular aspect of the invention may include a controlled-rate superabsorbent polymer in the absorbent system. Through the use of a controlled rate superabsorbent polymer, such as a selected renewed rate superabsorbent polymer, the concentration of liquid in fibrous structure of the designated distributor layer region can be maintained high even when the distribution layer region contains selected amounts. of superabsorbent polymer. In particular arrangements, the controlled low-rate superabsorbent polymer is primarily located in a layer region which is distinct from the distribution layer. As a result of this, the low superabsorbent polymer layer can be saturated selectively, while the overall absorbent capacity within a thin product design is maintained at a desired high level. It is contemplated that alternate mechanisms, other than the incorporation of a low-rate superabsorbent polymer, may be used to provide prorating and differences in the concentrations of liquid absorbed between the selected layer regions. For example, the desired apportionment can be generated by selectively configuring the relative wettability and / or density of the layer regions.

With reference to Figures 1 and 2, an absorbent composite system 26 of the invention includes an emergence management part 84, and a matrix or absorbent pad structure 30. The absorbent core or matrix 30 has multiple absorbent layer regions, and the properties of the individual layer regions are selected and arranged to provide improved runoff performance by balancing the take-up and transfer properties of the absorbent components.

Generally indicated, the absorbent core 30 of the present invention begins in the first layer which includes the superabsorbent (as determined when moving from the surface facing the innermost body of the article to the outermost surface of the article), together with any immediate component necessary to maintain the integrity of such layer during the functional test. Such a first layer desirably includes a minimum of not less than about 5 percent by weight of superabsorbent. The absorbent core ends in at least the absorbent layer which is positioned immediately before the layer essentially impermeable to the liquid which is designed to prevent runoff from the diaper, as determined when moving from the face surface to the body. inner of the article towards the outermost surface of the article. Thus, the absorbent core 30 of the configurations shown includes the first primary absorbent layer 48, the outermost layer of the wrapping sheet 28 or 36, and the components placed in sandwich form therebetween. The absorbent core of the illustrated configuration excludes the top sheet layer 24, the emergence management layer 84, which does not contain the superabsorbent and the bottom sheet layer 22.

The appropriate balance of intake and transport properties can be represented by several determining factors, such as the Flow Conductance Value, the transfer value, the basis weight, the density, the particle size, the fiber size, the quantity relative fiber, and the like, as well as combinations thereof. The Flow Conductance Value of the absorbent refers to the available void volume and the permeability of the structure through the various saturation levels typically found during the ordinary use. To provide improved performance for the absorbent system, the liquid should be allowed to enter the absorbent structure at a rate which is as close as possible to the rate at which the liquid is delivered to the absorbent composite structure. The Flow Conductivity Value can help to characterize the potential intake of the generally absorbent system 26, and can particularly help to characterize the take-up potential of the absorbent core 30. In addition, it is important to move the liquid out of the entry area for its storage in more remote areas of the absorbent system to thereby recondition and prepare the entrance area to more efficiently receive the next liquid discharge. The liquid transfer value can help characterize the ability of the absorbent structure to remove fluid from the entry target area between discharges.

With reference to FIGS. 2 and 2A, the absorbent matrix 30 has a general composite array 66, a general composite array width 68, and a general composite array thickness 70, a crotch array width 58 and a further border. designated front. The most front edge is designed to be placed in a front waistband section of the article. The overall composite assembly of the absorbent core 30 extends over and covers a general matrix area, as illustrated in Figure 2. The individual matrix component layers and the optional sublayers may extend over the entire superabsorbent core area, or may extend over a selected part of the core area as desired to provide the desired performance. In addition, each of the individual layer regions has individual dimensions. In the arrangement shown representatively, for example, a first layer region 48 has a first thickness or height 72, a first length 73 and a first width 74. A second layer region has a second thickness or height 75, a second length 66 and a second width 68.

With respect to the overall length 66 of the absorbent core 30, the intended take aim area 52 of the absorbent structure is a region of the absorbent core which begins on a laterally extending transverse direction line located at 24 percent of the length of the absorbent composite core length 66 outward from the most frontal front edge of the absorbent matrix, and extends to a line in the transverse direction located at 59 percent of the length of absorbent composite outward from the outermost edge of the core absorbent. In the illustrated arrangement, for example, the target area of the absorbent core may be an area of the absorbent structure which begins on a laterally extending line located approximately 89 millimeters from the most frontal front edge of the absorbent core and extends to the line that extends laterally located approximately 216 millimeters from the most frontal edge of the absorbent core.

It has been undesirable to increase the Flow Conductivity Value by increasing the volume of the absorbent matrix structure, because the thickness of the product can become excessive in articles having a narrow crotch width. As a result of this, there has been a continued need for configurations which provide the desired tap operation, as represented by the Flow Conductivity Value, while maintaining the thin absorbent core 30 and a thin absorbent system 26. Desirably, the total thickness of the dry absorbent core 30 is no more than about 6 millimeters. Alternatively, the thickness of the absorbent core may not be more than about 5.3 millimeters, and optionally, the thickness of the absorbent matrix may not be more than about 5 millimeters to provide the desired benefits. In another aspect of the invention, the thickness of the dry absorbent matrix 30 may not be more than about 25 percent of the width of the crotch of the absorbent matrix. Alternatively, the dry absorbent matrix thickness may not be more than about 20 percent of the crotch width of the absorbent matrix, and optionally may not be more than about 15 percent of the width of the crotch of the matrix absorbent to provide the desired benefits improved. For the purposes of the present disclosure, the crotch width of the absorbent matrix was determined in a narrower (smallest) side dimension of the crotch region located within the target area 52 of the array.

Desirably, the overall overall thickness of the dry absorbent system 26 is no more than about 8 millimeters. Alternatively, the thickness of the absorbent system can not be more than about 7.3 millimeters, and optionally, the thickness of the absorbent system may not be more than about 7 millimeters to provide the desired benefits. In another aspect of the invention, the overall thickness of the dry absorbent system 26 may not be more than about 30 percent of the crotch width of the absorbent system. Alternatively, the thickness of the dry absorbent matrix may not be more than about 25 percent of the crotch width of the absorbent system, and optionally, may not be more than about 20 percent of the crotch width of the absorbent system for provide the improved benefits.

For the purposes of the present disclosure, the dry thickness was measured at a restriction pressure of 0.2 psi (1.38 KPa).

In a further aspect of the invention, the low volume absorbent system 26, and particularly the absorbent matrix 30, may have a crotch region 54 designed to be placed between the user's legs where the narrowest (smallest) side dimension of the crotch region located within the target area 52 provides a minimum crotch width of 58. Therefore, a product for adult (intended for use by a person over the age of 13), may have a crotch width whose lateral dimension minimum is no more than about 14 cm when the absorbent compound is dry. Alternatively, the minimum crotch width 54 may not be more than about 11.4 cm, and optionally it will not be more than about 8.9 cm to provide improved notch and comfort. A non-adult product (intended for use by a person 13 years of age or younger) may have a crotch width whose minimum lateral dimension is no more than about 10 cm when the absorbent compound is dry. Alternatively, the minimum crotch width 54 may not be more than about 7.6 cm, and optionally shall be no more than about 5.1 cm to provide improved notch and comfort for non-adults.

It is also important to remove the liquid from the target area 52 of the absorbent system to effectively avoid over saturation of this area and the runoff of the article. The capacity of the absorber system to move the liquid out of the target region can be represented by the Liquid Transmission Value provided by the system. The transmission value is related to the amount of liquid which the system is able to move out of the target area when the target area has a liquid charge / saturation level of 1. grams of liquid per square centimeter of the area of objective of the absorbent compound. Therefore, the present invention provides a distinctive layered absorbent system which is thin, narrow in the crotch region and exhibits low volume.

The layer regions in the absorbent system are arranged to include a first side-by-side layer region which may be of various suitable configurations, but which typically has a size which is not larger than the size of the second region of outermost absorbent layer.

The first top layer region can maintain a low saturation level through the use of the absorbent article, and can maintain a high Flow Conductance Value when used in combination with the second lower layer region. The lower layer region can be selectively formed, such as with an hourglass or "T" configuration and is configured to efficiently distribute and move the liquid out of the target area of the absorbent composite. In particular, the The second lower layer region is capable of providing the desired values of the Liquid Transmission Potential, as can be determined by the Liquid Transmit Potential value method described below.

With reference to Figures 1, IA and IB, the invention can provide an absorbent article of garment, such as a diaper 20 having a longitudinal direction 86, and a lateral transverse direction 88. The article has a first section of waistband, such as the waistband section 40, a second waistband section, such as the front waistband section 38, and an intermediate section 42 h interconnects the first and second waistband sections. The front waistband section 38 has a laterally opposite front pair of side edge regions 118, the rear waistband section 40 has a laterally opposite rear pair of the side edge regions 116, and the middle section 42 provides a crotch region of article for placement between the legs of a user.

Figure 1 is a representative plan view of the representative disposable diaper 20 of the present invention in its non-contracted and flattened state (for example with essentially all elastic-induced folding and contraction removed). Parts of the structure are partially cut to show the construction more clearly inside of the diaper article, and the side surface to the body of the diaper h makes contact with the user faces the observer. The outer edges of the diaper define a periphery with the longitudinally extending side edge margins 110 and the laterally extending end edge margins 112. The side edges define the leg openings for the diaper, and optionally are curvilinear and they are contoured. The end edges are shown as straight, but. optionally they can be curvilinear.

A liquid-permeable top sheet layer 24 is overlapped in face-to-face relationship with the bottom sheet layer 22, and the absorbent system is operably connected and fixed between the bottom sheet layer 22 and the top layer sheet 24. The configuration shown representatively has an absorbent composite system 26 h includes an emergence management part 84 and a retention portion for containing and storing the liquid. The retaining portion of the illustrated absorbent system includes the absorbent core 30. In the configuration shown, the emergence management part 84 is a layer placed between the absorbent core 30 and the top sheet layer 24. Other arrangements may also be employed. For example, the emergence layer 84 can optionally be placed between the absorbent core and the bottom sheet layer 22 or on the side-to-body surface of the topsheet.

The article typically includes the elastomeric members, such as the leg elastics 34 and the waist elastics 32, and the emergence management part is placed in operative liquid communication with the retention portion of the absorbent article. The top sheet 24, the bottom sheet 22, the absorbent matrix 30, the emergence management part 84 and the elastic members 34 and 32 can be assembled together in a variety of well-known diaper configurations. The diaper may additionally include a containment flap system 82, and the side panel members 90 may be elasticated or otherwise made elastomeric.

Examples of the articles h include elasticized side panels and selectively configured fastener appendages are described in U.S. Patent Application Serial No. 168,615 of T. Roessler et al., Entitled "DIN MICO DIAPER DIAPER" and filed on December 16, 1993 (attorney's case number 10,961). Various techniques for forming the fastening systems are described in U.S. Patent No. 5,399,219 to T. Roessler et al., Entitled "METHOD FOR MAKING A DYNAMIC LINKAGE CLAMP" and issued on 21 March 1995 (lawyer's case number 11,186); and in the patent application of the United States of America series number 286.086 of D. Fries, entitled "A PROCESS FOR ASSEMBLING PARTS OF EAR ELASTIZADAS "and filed on August 3, 1994 (attorney's issue number 11,169) which was granted as the United States patent number 5,540,796, and in the United States patent application serial number 08 / 415,383 to D. Fries, entitled "A ASSEMBLY PROCESS FOR A LAMINATED TAPE" and filed on April 3, 1995 (attorney's issue number 11,950) which was granted as the United States patent number 5,595,618 The descriptions of the above-mentioned documents are incorporated herein by reference in a manner that is consistent therewith (not in conflict).

The diaper 20 generally defines the longitudinally extending length direction 86 and the laterally extending width direction 88, as representatively shown in Figure 1. The diaper may have any desired shape, such as the rectangular shape, the shape I, a generally hourglass shape, a T-shape. With the T-shape, the transverse bar of the "T" may comprise the front waistband portion of the diaper, may alternatively comprise the rear waistband portion of the diaper .

The upper sheet 24 and the lower sheet 22 may be generally coextensive, and may have length and width dimensions which are generally larger and they extend beyond the corresponding dimensions of the absorbent structure 26 to provide the corresponding side margins 110 and the end margins 112 which extend beyond the terminal edges of the absorbent structure. The upper sheet 24 is associated with and is superimposed on the lower sheet 22, thereby defining the periphery of the diaper 20. The waistband regions comprise those parts of the diaper which, when worn, completely or partially surround the waistband or the waistband. middle torso inferio of the user. The intermediate crotch region 42 lies between and interconnects the waistband regions 38 and 40, and comprises that portion of the diaper which, when worn, is placed between the wearer's legs and covers the lower torso of the wearer. Thus, the intermediate crotch region 42 is an area where repeated emergence of the liquid typically occurs in the diaper or other disposable absorbent article.

The lower sheet 22 may typically be located along a side-to-side surface of the absorbent 26 and may be composed of a liquid-permeable material, but desirably comprises a material which is configured to be essentially impermeable to liquids. For example, a typical bottom sheet can be made of a thin plastic film, another material impermeable to the essentially flexible liquid. As used in the present description, the term "flexible" refers to materials the which are docile and which will conform easily to the shape and general contours of the user's body. The lower sheet 22 prevents the exudates contained in the absorbent compound 26 from wetting the articles, such as the bed sheets and the overbeds, which make contact with the diaper 20. In the particular embodiments of the invention, the lower sheet 22 can include a film, such as a polyethylene film, having a thickness of from about 0.012 millimeters to about 0.051 millimeters. For example, the lower sheet film may have a thickness of about 1.25 mils.

The alternate constructions of the lower sheet may comprise a non woven or woven fibrous fabric layer which has been constructed or treated in whole or in part to impart the desired levels of liquid impermeability to the selected regions that are adjacent to or close to the absorbent composite. For example, the bottom sheet may include a layer of gas permeable nonwoven fabric laminated to a layer of polymer film which may or may not be gas permeable. Other examples of the fibrous cloth type bottom sheet materials may comprise a stretched or thinned thermal laminate stretched from a 0.015 millimeter thick polypropylene blown film and a polypropylene yarn bonded material of 23.8 grams per square meter (fibers). of 2 deniers). A material of this type forms the outer cover of the HUGGIES SUPREME diaper, which is commercially available from Kimberly-Clark Corporation. The lower sheet 22 typically provides the outer cover of the article. Optionally, however, the article may include a separate outer cover component member which is additional to the lower sheet.

Lower sheet 22 may alternatively include a microporous "breathable" material which allows gases, such as water vapor, to escape from absorbent 26 while essentially preventing liquid exudates from passing through the sheet lower. For example, the bottom breathable sheet may be composed of a microporous polymer film or a nonwoven fabric which has been coated or otherwise modified to impart a desired level of liquid impermeability. For example, a suitable microporous film may be a PMP-1 material, which is available from Mitsui Toatsu Chemicals, Inc., a company having offices in Tokyo Japan; or a polyolefin film XKO-8044 available from 3M Company of Minneapolis, Minnesota. The bottom sheet can also be engraved or otherwise provided with a matte pattern or finish to exhibit a more aesthetically pleasing appearance.

In the various configurations of the invention, wherein a component such as the bottom sheet 22 or the fins of containment 82 are configured to be gas permeable while having a limited resistance and permeability to the aqueous liquid, the liquid resistant material can have a construction which is capable of holding a hydro head of at least about 45 cm of water without a runoff through it. A suitable technique for determining the resistance of a material to liquid penetration is the Federal Test Method Standard FTMS 191 Method 5514, dated December 31, 1968, or an essentially equivalent procedure.

The size of the lower sheet 22 is typically determined by the size of the absorbent composite 26 and the selected diaper design. The lower sheet 22, for example, may have a generally T-shaped, generally I-shaped or a modified hourglass shape and may extend beyond the terminal edges of the absorbent composite 26 for a selected distance, such as a distance within the range of about 1.3 cm to 2.5 cm (about 0.5 to 1.0 inch) to provide at least part of the lateral and end margins.

The topsheet 24 has a body facing surface which is docile, soft feeling and non-irritating to the wearer's skin. In addition, the topsheet 24 can be less hydrophilic than the absorbent 26 and is sufficiently porous to be permeable to liquid, allowing the liquid to easily penetrate through its thickness to reach the absorbent body compound. A suitable top sheet layer 24 can be made from a wide selection of fabric materials, such as porous foams, cross-linked foams, perforated plastic films, natural fibers (e.g., cotton or wood fibers), synthetic fibers (e.g. example, polyester or polypropylene fibers) or a combination of natural and synthetic fibers. The top sheet layer 24 is typically employed to help isolate the wearer's skin from liquids maintained in the absorbent 26.

Various woven and non-woven fabrics can be used for the upper sheet 24. For example, the upper sheet can be composed of a fabric spun or blown with melting of the desired fabrics, and can also be a bonded-carded fabric, a fabric hydroentangled, a perforated fabric or the like, as well as combinations thereof. The various fabrics can be composed of natural fibers, synthetic fibers or combinations thereof. Optionally, the top sheet may include a network material or a perforated film.

For the purposes of the present description, the term "non-woven fabric" means a fabric of fibrous material which is formed without the aid of a weaving or screening process • * textile. The term "fabric" is used to refer to all woven, woven and non-woven fibrous fabrics, as well as combinations thereof.

The top sheet fabrics can be composed of an essentially hydrophobic material, and the hydrophobic material can be optionally treated with a surfactant or otherwise processed to impart a desired level of wettability and hydrophilicity. In a particular embodiment of the invention, the topsheet 24 is a polypropylene fabric bonded by non-woven yarn composed of fibers of about 2.8-3.2 denier formed into a fabric having a basis weight of about 22 grams per square meter and a density of about 0.06 grams / cm3. The fabric is treated on the surface around 0.28% of a Triton X-102 surfactant. The surfactant can be applied through any conventional means, such as spraying, printing, brushing and the like.

The top sheet 24 and the bottom sheet 22 are connected or otherwise associated together in an operable form. As used herein, the term "associated" encompasses configurations in which the upper sheet 24 is directly attached to the lower sheet 22 by attaching the upper sheet 24 directly to the lower sheet 22, and the configurations wherein the upper sheet 24 is united indirectly to the lower sheet 22 by fixing the upper sheet 24 to intermediate members which can in turn be fixed to the lower sheet 22. The upper sheet 24 and the lower sheet 22 can, for example, be fixed directly to each other in the periphery of the diaper by means of the fastening devices (not shown) such as the adhesive bonds, the sonic joints, the thermal joints, the sewing or other fastening means known in the art, as well as the combinations thereof. For example, a continuous and uniform adhesive layer, a patterned adhesive layer, a sprayed adhesive pattern or an array of separate lines, swirls or adhesive construction points can be used to secure the top sheet 24 to the bottom sheet 22. It should be readily appreciated that the joining means described above can also be employed to properly interconnect, assemble and / or secure together the various other component parts of the articles which are described herein.

The representatively shown article has an absorbent system which includes the emergence layer 84 and the retention portion for containing and storing the absorbed liquids and other waste materials. In particular aspects of the invention, the retaining or storage part is provided by the absorbent core structure shown 26 which is composed of multiple layers of selected fibers and high absorbency particles. The The shown configuration of the absorbent composite is placed and sandwiched between the topsheet 24 and the bottomsheet 22 to form the diaper 20. The absorbent composite has a construction which is generally compressible, conformable, non-irritating to the wearer's skin and able to absorb and retain body exudates.

In the various configurations of the invention, many suitable types of wettable hydrophilic fibrous materials can be used to form any of the various component parts of the absorbent article. Examples of suitable fibers include naturally occurring organic fibers composed of an intrinsically wettable material, such as cellulosic fibers, synthetic fibers composed of cellulose or cellulose derivatives, such as rayon fibers; inorganic fibers composed of an inherently wettable material, such as glass fibers; synthetic fibers made of inherently wettable thermoplastic polymers, such as particular polyester or polyamide fibers; and synthetic fibers composed of a non-wettable thermoplastic polymer such as polypropylene fibers. The fibers can be hydrophilized, for example, through treatment with silica, treatment with a material which has a suitable hydrophilic moiety and is not easily removable from the fiber, or by sheathing the hydrophobic fiber not wettable with a polymer. hydrophilic during or after fiber formation. For the purposes of the present invention, it is contemplated that mixtures selected from the various types of fibers mentioned above may also be employed.

As used herein, the term "hydrophilic" describes fibers or the surfaces of the fibers which are wetted by the aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of contact angles and the surface tensions of the liquids and materials involved. Equipment and techniques suitable for measuring wetting of particular fiber materials or blends of fiber materials can be provided by the Cahn SFA-222 Surface Force Analyzer System or through an essentially equivalent system. When measured with such a system, fibers having contact angles of less than 90 ° were designated "wettable", while fibers having contact angles equal to or greater than 90 ° were designated "non-wettable".

In particular, the absorbent core structure 30 may comprise one or more fiber matrices, such as a fabric of natural fibers, synthetic fibers and the like, as well as combinations thereof. Desirably, the fibers are hydrophilic, either natural or through the effects of a conventional hydrophilic treatment. Particular arrangements may include a fibrous matrix composed of cellulose wood pulp fluff. It should be readily appreciated that each of the primary layer regions 48 and 50 may include the same types of fibrous matrices or may include different types of fibrous matrices.

In particular aspects of the invention, the fibers in one or more of the primary layers 48 and 50 may be mixed or otherwise incorporated with particles of high-absorbency material. The fibers in the selected layer or layers are arranged in an absorbent matrix and desirably, each of the layers 48 and 50 may include fibers combined with particles of the high-absorbency material. In particular arrangements, for example, the designated layer of the absorbent core 30 may comprise a mixture of superabsorbent hydrogel-forming particles and natural fibers, synthetic polymer meltblown fibers, a fibrous coform material comprising a mixture of natural fibers and / or of synthetic polymer fibers. The superabsorbent particles can be mixed in an essentially homogeneous way with the hydrophilic fibers, or they can be mixed non-uniformly. For example, the concentrations of the superabsorbent particles can be arranged in a non-stepped gradient through an essential part of the thickness (z-direction) of the absorbent structure, with lower concentrations towards the body side of the absorbent body and relatively higher concentrations toward the outer side of the absorbent structure. Suitable z-gradient configurations are described in U.S. Patent No. 4,699,823 issued October 13, 1987 to Kellenberger others, the complete disclosure of which is incorporated herein by reference in a form that is consistent (not conflicting) with the present description. Alternatively, the concentrations of the superabsorbent particles may be arranged in a non-stepped gradient across an essential part of the thickness (z-direction) of each layer of the absorbent structure, with the higher concentrations towards the body side of the absorbent compound and the relatively lower concentrations towards the outer side of the absorbent structure. The superabsorbent particles may be arranged in a generally discrete layer within the matrix of hydrophilic fibers. In addition, two or more different types of superabsorbent can be selectively placed at different places within or along the fiber matrix.

The high-absorbency material may comprise absorbent gelation materials, such as superabsorbents. The absorbent gelation materials can be polymers and natural, synthetic and modified natural materials. In addition, the absorbent gelation materials can be inorganic materials, such as silica gels or organic compounds, such as polymers cross-linked. The term "cross-linked" or "degraded" refers to any means for effectively making materials normally soluble in water essentially insoluble but swellable in water. Such means may include, for example, physical entanglement, crystalline domains, covalent bonds, complexes and ionic associations, hydrophilic associations, such as hydrogen bonding, and hydrophobic associations or Van der Waals forces.

Examples of the synthetic absorbent gelation material polymers include the alkali metal and ammonium salts of poly (acrylic acid) and poly (methacrylic acid), poly (acrylamides), poly (vinyl ethers), maleic anhydride copolymers with vinyl ethers and alpha-olefins, poly (vinyl pyrrolidone), poly (vinyl morpholinone), poly (vinyl alcohol) and mixtures and copolymers thereof. Additional polymers suitable for use in the absorbent include natural polymers and modified natural polymers, such as hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, methyl cellulose, chitosan, carboxymethyl cellulose, hydroxypropyl cellulose , and natural gums, such as alginates, xanthan gum, locust bean gum and the like. Mixtures of natural and fully or partially synthetic absorbent polymers can also be used in the present invention. Other suitable absorbent gelation materials are described by Assarsson and others in U.S. Patent No. 3,901,236 issued August 26, 1975. Processes for preparing the synthetic absorbent gelation polymers are described in the US Pat. United States of America No. 4,076,663 issued February 28, 1978 to Masuda et al., and United States Patent No. 4,286,082 issued August 25, 1981 to Tsubakimoto et al.

Synthetic absorbent gelation materials are xerogels which form hydrogels when wetted. The term "hydrogel" however, has been commonly used to also refer to both wet and unmoistened forms of the material.

As previously mentioned, the high absorbency material used in the absorbent matrix 30 can be a superabsorbent gelation material, and the superabsorbent can generally be in the form of discrete particles. The particles can be of any desired shape, for example, spiral or semi-spiral, cubic, or rod-type, polyhedral, etc. The shapes having a smaller dimension / larger dimension ratio, such as needles, leaflets and fibers are also contemplated for use here. Optionally, the particle conglomerates of the absorbent gelation material they can also be used in the absorbent compound 26. The particles are desired to be used having an average size of from about 5 microns to about 1 millimeter. E "particle size" as used herein means the heavy average of the smallest dimension of the individual particles.

In particular aspects of the invention, the particles of absorbent gelation material can have a Modified Absorbency Under Load (MAUL) of at least d about 20 grams of liquid absorbed per gram of absorbent material (g / g) • Desirably, the The superabsorbent material may have a modified absorbency under load of at least about 24 g / g, and more desirably may have a modified absorbency of at least about 27 g / g. In additional aspects, the superabsorbent material may exhibit a modified absorbency under a load of about 30 g / g or more. The modified absorbency value under load can be measured using the modified absorbance test method under load described in the test procedure section of the present disclosure.

The hydrophilic fibers and high-absorbency particles in the total composite core 30 can be configured to form an average composite basis weight which is within the range of about 400-900 grams per square meter (g / m2). In certain aspects of the invention, the average composite basis weight is within the range of about 500-800 grams per square meter, and preferably is within the range of about 550-750 grams per square meter to provide the desired performance.

In particular aspects of the invention, the high-absorbency material may include a superabsorbent non-woven material. The non-woven superabsorbent is a non-woven material which is composed of superabsorbent fibers alone or is composed of superabsorbent fibers and other materials. The superabsorbent nonwoven material has a higher ultimate liquid storage capacity when immersed in a liquid, particularly a 0.9% salt water solution, with a liquid holding capacity of at least about 10 grams of the absorbed liquid per gram of absorbent material (g / g). Alternatively, the liquid holding capacity is at least about 20 g / g, and optionally is at least about 30 g / g to provide the improved performance characteristics. The superabsorbent nonwoven is selectively configured to promote liquid intake, liquid storage, liquid distribution or some combination of these functions. In particular, the superabsorbent nonwoven can be designed to perform a specific function or a set of functions when the non-woven superabsorbent is incorporated as a layer or a component in a product having a multi-layer absorbent structure.

To limit any unwanted movement of the high-absorbency material, the article may include the absorbent composite 26, having an overwrap, such as the wrapping sheet 28 which is placed immediately on one side and around the entire absorbent core 30, around a single layer region of the core, or around one or more selected components of the absorbent compound as desired. In addition, the wrapping sheet may be attached to the absorbent composite structure and to the various other components of the article. The wrapping sheet is preferably a layer of an absorbent material which covers the side-to-body and side-to-side surfaces of the absorbent compound, and preferably encloses essentially all of the peripheral edges of the absorbent compound to form an essentially complete envelope around it. of the same. Alternatively, the wrapping sheet can provide an absorbent wrap which covers the main side-to-body and side-to-side surfaces of the absorbent composite, and essentially encloses only the side-side edges of the absorbent composite. Therefore, both inwardly and linearly arched portions of the lateral side edges of the wrapping sheet can be closed around the absorbent composite. In such an arrangement, however, the end edges of the sheet The wrapping may not be completely closed around the end edges of the absorbent compound of the waistband regions of the article.

For example, the entire wrapping sheet 28, or at least the side-to-body layer of the wrapping sheet, may comprise a meltblown fabric composed of meltblown fibers, such as meltblown polypropylene fibers. Another example of the absorbent wrap 28 may comprise a low porosity cellulosic fabric, such as a tissue composed of a mixture of approximately 50/50 hardwood / softwood fibers.

The absorbent wrap 28 may comprise a multi-element wrapping sheet which includes a separate side-to-body wrapping layer and a separate outer-side wrapping layer, each of which extends beyond all or some of the peripheral edges of the absorbent core 30. Such a configuration of the wrapping sheet may, for example, facilitate the formation of a complete seal and closure essentially around the peripheral edges. of the absorbent core 30. In the back waist portion of the illustrated diaper, the absorbent wrap may also be configured to extend for an increased distance outwardly from the periphery of the absorbent core to add opacity and strength to the underside sections of the absorbent core. diaper. In the illustrated embodiment, the side-to-body and outer-side layers of the absorbent wrap 28 may extend at least about 1/2 inch past the peripheral edges of the absorbent core to provide a bonding area of type of outwardly projecting flange on which the periphery of the side portion to the body of the absorbent casing can be completely or partially connected to the periphery of the side portion to the outside of the absorbent casing.

The side-to-body layers and the side-to-side layers of the wrapping sheet 28 may be composed of essentially the same material, or may be composed of different materials. For example, the outer side layer of the wrapping sheet may be composed of a relatively lower basis weight material having a relatively higher porosity, such as the moisture resistant cellulosic tissue composed of soft wood pulp. The side-to-body layer of the wrapping sheet may comprise one of the previously described wrapping sheet materials which has a relatively low porosity. The low porosity side-to-body layer can better prevent migration of the superabsorbent particles onto the user's skin, and the lower porosity base-side layer of lower porosity can help reduce costs.

With reference to Figures 7, 8 and 9, another absorbent core of the invention may include a component having particles of a superabsorbent material 102 operatively held between the layers of the liquid permeable material 100, such as the layers of tissue, the foam of open cell, porous films, nonwoven fabric, woven fabric or the like, as well as combinations thereof. In particular aspects of the invention the bottom layer 50 may be composed of a laminate having superabsorbent particles placed in the form of a sandwich or otherwise held between the layers of the supported carrier tissue with water-sensitive accessories. Examples of such configurations are described in U.S. Patent No. 5,593,399 issued January 14, 1997, issued to R. Tanzer et al. And entitled ABSORBENT ARTICLE WHICH INCLUDES SUPERABSORBENT MATERIAL LOCATED IN DISCRETE LENGTHED BAGS. PLACED ON SELECTED PATTERNS (attorney's issue No. 10,902.1) whose full description is incorporated herein by reference in a manner that is consistent therewith.

Referring again to FIGS. 1 and 2, diaper 20 may also include an emergence management layer 84 which helps to slow and diffuse liquid surges that can be directed to the retention and storage portion of the absorbent article. The emergence layer 84 can, for example, be located on a side surface to the inwardly facing body of the upper sheet layer 24. In the configuration shown representatively, the emergence layer 84 is located on one side of a side-to-side surface of the upper sheet layer. Thus, the emergence layer is interposed between the topsheet 24 and the absorbent core 30. Examples of suitable emergence management layers 84 are described in U.S. Patent Application Serial No. 206,986 of C Ellis and D. Bishop, entitled FIBROUS NON-WOVEN FABRIC SURFACE CAPACITY FOR ABSORBENT PERSONAL CARE AND SIMILAR ITEMS, filed on March 4, 1994 (attorney's case No. 11,256) which was issued as the patent for the United States of America No. 5,486,166; and U.S. Patent Application Serial No. 206,069 to C. Ellis and R. Everett, entitled FIBROUS NON-WOVEN FABRIC OF IMPROVED EMERGENCY MANAGEMENT FOR ABSORBENT PERSONAL CARE AND SIMILAR ITEMS, filed March 4, 1994 (attorney's case No. 11,387) which was granted as United States of America Patent No. 5,490,846; whose complete descriptions of which have been incorporated herein by reference in a manner that is consistent therewith.

With reference to Figures 1 and 2, particular aspects of the invention may include an absorbent compound which includes a selected plurality of two or more primary layer region components. The configuration of the illustrated multilayer absorbent core 30, for example, includes a first layer region 48 and at least a second layer region 50.

The first layer region shown representatively 48 provides a relatively high layer region which is positioned over the body-to-body region of the absorbent core 30 and is relatively closer to one side of the top sheet layer 24. The second region of Illustrated layer 50 provides a relatively lower layer region which is positioned on the side-to-side region of the absorbent core and is in a relatively close to one side of the lower sheet layer 22.

In a desired aspect of the invention, the components in the various layer regions, such as layer regions 48 and / or 50, may include a mixture or other high volume fiber matrix. High volume fibers are those which impart improved volume retention and / or recovery from deformation. The high volume fibers can particularly provide a wet volume retention and / or a wet recovery of the strain when the fibers are incorporated into materials which become wet. Examples of suitable high-volume fibers include synthetic fibers, thermoplastics, synthetic fibers composed of natural polymers such as cellulose and natural fibers such as combinations thereof. The elasticity of fibers composed of natural polymers can be improved by chemical degradation and / or by imparting a twist and / or curl to the fiber.

The high volume fibrous materials are capable of exhibiting a lower density in both the wet state and the dry state, and therefore increase the permeability and thickness, thus increasing the Flow Conductivity Value. For example, high volume wood pulp fibers can be achieved through various techniques, such as chemical and / or mechanical modifications of pulp fibers. Examples of suitable high volume fibers include mercerized fibers, degraded cellulose fluff pulp fibers and the like, as well as combinations thereof.

In another aspect of the invention, the components in the various layer regions, such as layer regions 48 and / or 50, may be composed of a mixture or other high volume fiber matrix and a controlled rate superabsorbent. The controlled rate superabsorbent is a material, such as a superabsorbent polymer material, which demonstrates a modified load absorbency value (MAUL) of at least a minimum of about 20 g / g.

In other aspects of the invention, the desired controlled rate superabsorbent can exhibit a particular absorbance rate, a Tau (T) value, such as the Tau value which is at least a minimum value of about 0.4 min. Desirably the superabsorbent Tau value is at least about 1 min, and may be at least 2 min, to provide improved performance. In still other aspects, the Tau value can be up to around 40 minutes or more. In other aspects, the absorbent core, particularly the different layer regions of the absorbent core, can advantageously incorporate a selected combination of the superabsorbent materials wherein at least one selected pair of the different superabsorbent materials are configured to provide a proportion of Tau value. which is equal to or greater than about 2: 1. The Tau value ratio may optionally be up to about 5: 1, or more, to provide the additional benefits. Desirably, the superabsorbent material having the relatively higher Tau value is placed relatively closer to the body-side surface of the absorbent core. A suitable technique for determining the Tau value of each superabsorbent is described in the Zero Load Flooded Absorbency procedure set forth in the present description.

A particular controlled rate superabsorbent can be a superabsorbent where the particles Individual superabsorbents are treated with a hydrophobic coating to provide a selected delay in the absorption of aqueous liquids inside the particles. For example, the superabsorbent may be a coated particulate superabsorbent. The particles have absorbent centers composed of a partial sodium salt of a degraded polypropionic acid (prepared by the process described in U.S. Patent No. 5,629,377) and the particle centers are covered with an elastomer coating of hydrophobic silicone. A representative controlled rate superabsorbent of this type is available from Dow Chemical Company, a business having offices in Midland, Michigan, United States of America.

An alternate controlled rate superabsorbent can be configured with relatively large particle sizes to provide particles having a low surface area to volume ratio which therefore produces the desired absorbance rate. The controlled-rate superabsorbent particles may also have an essentially spherical or other three-dimensional shape that operatively generates the desired low surface-area-to-volume ratio and the delayed absorbency rate.

In addition, the volume chemistry of the superabsorbent polymer can be modified to provide the rate of desired delayed absorbency. For example, the controlled rate superabsorbent may incorporate an anionic polyelectrolyte which is cross-linked reversibly with a polyvalent metal cation. A water-soluble complexing agent can be configured to reverse the degradation.

Alternate controlled rate superabsorbents can be pigeonholed by a coating or other treatment which operatively decelerates the diffusion of the liquid into the superabsorbent particles, or repels the liquid in a manner which provides the desired delayed absorbency rate. The coatings or treatments may be elastic or inelastic, or the coating or treatment may be hydrophobic or hydrophilic. The coatings can be eroded, dissolved or cracked in a controlled manner to provide the desired absorbency characteristics. Optionally, the absorbency rate can be limited and / or controlled by modifying the neutralization rate of the selected superabsorbent material or by modifying or otherwise controlling the chemical mechanism employed to produce the neutralization of the selected superabsorbent.

Additional aspects of the determination of the Absorbency Under Loading (AUL) of a superabsorbent are described in U.S. Patent No. 5,550,189 issued Aug. 26, 1996 to J. Qin et al. entitled MODIFIED POLYSACCHARIDES WHICH HAVE IMPROVED ABSORBENT PROPRIETORS AND PROCESSES FOR THE PREPARATION OF THEMSELVES; and in the United States patent application of North America Series No. 621,390 of M. Melius et al., filed on March 25, 1996 and entitled ABSORBENT COMPOUND (attorney's note No. 10,838.2). The full descriptions of these documents are incorporated by reference in a manner that is consistent with it.

With reference to Figures 2 and 2A, the first layer region shown representatively 48 may include a controlled rate superabsorbent, and a high volume wood pulp fiber and other woven or nonwoven fibrous material with pore size distributions that they allow a rapid intake of the liquid while maintaining the liquid inside the structure until it is absorbed by the layer region or relatively outer layer regions of the absorbent. The components in the first part of the layer region 48 can be placed to essentially cover the designated target area 52 of the product., the area where liquids, such as urine, are introduced into the absorbent structure. Thus, the first layer region 48 can operatively be a designated take-up layer region of the absorbent core. The shape of the layer region 48 can be rectangular, non-rectangular or irregular in shape, but desirably will not be larger than the underlying layer region, such as the second layer region. 50. In the desired aspects of the invention, the first layer region will be smaller than the second layer layer region. For example, a substantial totality of the first primary layer region may be contained within a zone which begins in a laterally extending line placed at about 7% of the length of the core inward of the most frontal edge of the absorbent core. and extends to a laterally extending line positioned at about 62% of the core length inward of said more frontal edge of the absorbent core. In addition, the longitudinally extending side edges of the first primary layer region may be substantially coterminous with the corresponding side edges of the second primary layer region.

Additional examples of the alternate absorbent configurations are shown representatively in Figures 3 to 6. In particular aspects of the invention, the first layer region 48 may include a composite structure having a plurality of component sublayer parts.

Figures 3 and 3A representatively show a top view of an absorbent matrix structure having a first top layer region 48 which extends over a middle part of the total area of the absorbent matrix 30, and a second bottom layer region 50 which extends over essentially the entire area of the absorbent matrix. The second layer region 50 has a non-uniform zoned base weight distribution with a relatively greater basis weight at its longitudinally opposite end portions to provide a longitudinal inverse zoning of the second lower layer region particularly in the target area. The selected middle part of the second layer region 50 can also have a basis weight which is lower than that of the first adjacent overlying layer region 50, to provide an inverse zoned thickness in the target area. At least in the crotch region of the absorbent matrix 30, the lateral side edges of the upper layer region 48 are substantially coterminous with the side edges of the second layer region 50. Each of the longitudinal end edges of the first layer region 48 are spaced inward from the corresponding end edges of the second layer region 50.

Figures 4 and 4A representatively show an absorbent core structure having a top layer region 48 which covers a complete front or first complete part of the bottom layer region 50, but covers less than the second or full back part of the background layer region. The lateral side edges of at least one longitudinal end edge of the first layer 48 are substantially coterminous with the side side edges and at least one longitudinal end edge of the second layer region 50.

In the configuration shown, at least one longitudinal end edge of the first layer region 48 is spaced apart inwardly from a corresponding end edge of the second layer region 50.

Figures 5 and 5A representatively show an absorbent core structure having a top layer region which completely covers a bottom layer region. Although the configuration shown has a first layer region 48 and a second layer region 50 with essentially the same thicknesses and basis weights, the first and second layer regions may alternatively have different thicknesses and different base weights, as well as other differences in the structure.

Figure 6 representatively shows a top view of another absorbent core with an upper layer region which both have a smaller narrower side dimension and a shorter longitudinal length smaller than the bottom layer region. In the configuration shown, for example, essentially the entire outer edge perimeter of the first layer region 48 is spaced inward from essentially the entire outer edge perimeter of the second layer region 50.

In the various configurations of the invention, the controlled rate superabsorbent can be configured to help regulate the liquid storage rate in the various layer regions of the absorbent system. The controlled rate superabsorbent can provide a liquid storage rate control in an absorbent only as a result of the presence of the controlled superabsorbent material (SAM) or in a combination of the superabsorbent with other materials to provide a controlled rate superabsorbent compound . A superabsorbent composite or a controlled rate superabsorbent employing the controlled rate superabsorbent can be used as an absorbent layer region in a multi-layer region absorbent, particularly when the controlled rate superabsorbent or the rate superabsorbent composite Controlled is selectively configured to promote preferential saturation of one or more other layer regions in the multi-layer absorbent core during the conditions in use. By using a combination of the high volume fibers and the controlled rate superabsorbent, the saturation in the first layer region 48 can be maintained at a saturation level which is lower than that of the other absorbent layer regions, resulting in in a higher void volume and permeability in the first layer region 48, and providing the desired levels of the Flow Conductivity Value.

The compound consisting of the high-volume fiber, particularly the pulp fiber, and the superabsorbent can also be modified by introducing a stabilizing agent into the composite material. The stabilization structure can be used to maintain or minimize changes to the structure of a particular material or to the structure of the composite of materials when exposed to external or internal forces. The structure stabilization mechanism can benefit any layer region in the multiple layer region absorbent by helping to maintain the structure of the layer region when it is exposed to forces applied under the conditions during use for the products that incorporate the multiple layer absorbent core. This will help the layer region maintain its proposed function, whether it is liquid intake (hollow volume generation), liquid storage, liquid distribution or some combination of these three functions. Several types of technologies of suitable material can be used to stabilize the absorbent structures. For example, the stabilization can occur either in the form of a chemical stabilization, such as with Kymene or another cross-linking agent or by the introduction of thermoplastic binder fibers or the like.

In the various aspects of the invention, the upper layer region 48 may be composed of a fibrous material based on a woven or non-woven technology. As in the prior aspects of the invention, these materials will be configured to provide maximum hollow volume and permeability while maintaining sufficient capillary tension to control the movement of the liquid and not allow runoff to occur. For example, the absorbent cores of the present invention can incorporate non-woven materials as functional components for the upper layer region 48. The carded and bonded fabrics are examples of particular fibrous materials that can be configured to provide an adequate balance of permeability and capillarity Through the selection of short fiber options, one can create a composite structure that will preferably saturate the bottom absorbent layer 50. This can be done either through the physical structuring of the top layer, the surface chemistry or both of them. The porosity of the fibrous structures can be determined by means of the specific fibers and the selected fiber sizes. The selection of fiber can also impact the capillarity of the material.

Suitable carded structures have been produced from a variety of fiber types and from a variety of fibers. The fibers can be produced from both naturally occurring and synthetic materials. Desirably, the fibers for the first layer 48 would be very wettable, and the Natural cellulosic materials such as rayon or cotton would be employed. Synthetic fibers such as polyester and polyamide offer limited wettability which can be improved with hydrophilic finishes or treatments. Even though fiber diameters of a fairly wide range occur in carded non-wovens the desired structure will contain fibers with equivalent diameters of less than 25 microns. A carded material for the first layer 48 will be produced in a weight range of from about 50 to 200 grams per square meter (gsm) at a density of about 0.03 g / cc or less. The density of the fibrous material will ultimately depend on the method used to bind or stabilize the fabric.

Carded and bonded fabrics can be stabilized through various methods. The incorporation of thermoplastic short fibers is used in some cases so that the structure can be joined using heat and pressure.

The proper application of heat and pressure in the thermal bond can result in a structure that is stabilized with a very specific permeability and capillarity. The carded structures can also be stabilized using resins or chemical adhesives. Again, the selection of the resin or the specific adhesive, of the added quantities and curing will facilitate the control of the properties of the final fabric that will impact permeability and capillarity. Wettability can be impacted by the choice of chemical resin system for the Union. The carded structures can be mechanically stabilized using water, perforation, air or other means to entangle the fibers. Again, these processes can be controlled in such a way that the physical attributes of the material are as desired.

Particular aspects of the invention may incorporate a spunbonded fabric with similar properties to those described above. Other aspects of the invention may include a zoning selected from the fiber size, basis weight or other characteristics of the material to provide desired performance attributes. In addition to carded fibrous fabrics and fibrous webs joined together by spinning, fibrous materials placed by air can also be used. The component materials in the first layer 48 region may be in the amounts, basis weights, densities, etc. which are described below. The base weights typical of the region of the absorbent core structure which is placed in a front mid-section of the article can be from about 750 grams per square meter to about 950 grams per square meter. The first layer region, as described above, can provide anywhere from about 25% to about 75% of the overall basis weight in those areas where the first layer is present. The proportion depends very highly on the materials that are being used and their relative efficiencies. The materiale in which the superabsorbent materials are used in combination with the fluff and / or some short fibers will usually have an initial density of 0.1 g / cc to 0.3 g / cc. The materials which are synthetic based, carded fabrics and fabrics bonded with melt, will typically have a density of about 0.015 g / cc to 0.3 g / cc, and desirably will have a density of about 0.2 g / cc. Synthetic fiber fabrics will typically have fiber sizes of less than 3 denier and preferably 1-2 denier and will be treated to exhibit a low contact angle with water through various wettings. The treatment desirably does not reduce the surface tension of the liquid passing through the fibrous web.

Other non-woven structures may also be suitable for use as the upper layer region 48 in the absorbent system of the invention. An adequate balance of the capacity and capillarity of the lower layer region can ensure a preferential saturation of the lower layer region over multiple discharges. One can visualize using a different lower layer region which has a greater distribution capacity. This would help in the desorption of the non-woven top layer region and should improve the operation after the second discharge.

The desired aspects of the invention may have a Liquid Transmission Value which is at least about 38% value. Other aspects of the invention may have a value of at least about 24%, and a Flow Conductivity Value which is at least about 4 x 1 or 6 cm 3. In still other aspects, the invention may have a Combined Conductance Transmission Value (C) which is at least about 14 * 10"6 cm3.

The desired combinations of the Values d Transmission and Flow Conductance can provide an advantageous balance of the liquid handling characteristics. In particular, the combinations can provide a desired balance of rapid liquid intake along with a rapid transport of the absorbed liquid out of the target area. more remote areas of the absorbent structure. Conventional structures have not provided the desired combination of properties. Therefore, the structures which have provided a desired rapid intake have not provided sufficient rapid transport of the liquid absorbed towards the intake area and the structures which have provided a desired rapid transport of the liquid absorbed towards the intake area. They have provided a quick enough intake of the liquid. As a result of this, there may be excessive and premature saturation of the absorbent target area, or excessive stagnation of the liquid against the user's skin.

In particular aspects of the invention, the first layer region 48 may be an upper body-to-body layer which may typically extend over a longitudinal middle section of the general core area, but may optionally extend over the entire core area if it is you want The top layer is typically the layer which is optimized for tap operation and may or may not provide desired levels of liquid transmission or distribution operation. The first layer region typically can have a minimum basis weight of not less than about 100 grams per square meter, and desirably can have a basis weight of not less than about 300 grams per square meter. In additional aspects, the first layer region typically can have a maximum basis weight of no more than about 700 grams per square meter, and desirably has a basis weight of no more than about 600 grams per square meter.

The first layer part typically includes a minimum of not less than about 50% fibrous material by weight (% by weight) and desirably includes not less than about 60% fibrous material. In other aspects, the first layer typically may include a maximum of no more than about 80% of the fibrous material, and desirably may include no more than about 70% of the fibrous material. The fibrous material can be natural or synthetic in nature. The fibrous material may have a minimum fiber size, particularly a fiber diameter of at least about 4 microns (μm) and desirably have a fiber size of at least about 10 microns. In additional aspects, the fibrous material may have a maximum fiber size of no more than about 20 microns, and desirably have a fiber size of no more than about 15 microns.

The first layer part may also contain a minimum of not less than about 20% superabsorbent material by weight, and desirably contains no less than about 30% superabsorbent. In additional aspects, the first part of the layer may include a maximum of no more than about 50% superabsorbent material, and desirably may include no more than about 40% superabsorbent. The superabsorbent material may have a minimum dry particle size of not less than about 110 microns, and desirably have a dry particle size of not less than about 300 microns. In other aspects, the superabsorbent material may have a maximum dry particle size of no more than about 1000 microns, and desirably may have a dry particle size of no more than about 700 microns. The superabsorbent material can also have an absorbency value modified under load of not less than about 20 g / g and desirably may have a modified absorbency value under load of not less than about 25 g / g. Additionally the modified absorbency value under load may be up to about 30 g / g or more to provide improved benefits. In still other aspects, the superabsorbent material may have a Tau value of at least about 0.8 minutes and may have a Tau value of up to about 40 minutes.

The first layer region 48 can typically have a minimum average density of at least about 0.03 g / cc and desirably has a density of at least about 0.05 g / cc. In other aspects, the first layer region may have a maximum average density of no more than about 0.4 g / cc, and desirably may have a density of no more than about 0.2 g / cc. The first layer region includes any layers of tissue which can be used to hold together the materials placed in the first layer region or which act as a barrier mechanism. For example, several layers of tissue may be employed to contain the superabsorbent material which is laminated between the layers of tissue.

The various configurations of the invention can include any operational take-up material in the layers selected from the absorbent structure. Examples of suitable picking materials may include the materials described in the United States patent application Serial No. 754,414 entitled MULTIFUNCTIONAL ABSORBENT MATERIAL AND PRODUCTS MADE FROM THEM BY R. Anderson et al. And filed on 22 November 1996 (lawyer case No. 12,422); and in the provisional patent application of the United States of America Series No. 068,534 entitled PULP COMPOUND AND SUPERABSORBENT FOR IMPROVED TAKING OPERATION, of L. H. Sawyer et al., And filed on December 23, 1997 (attorney's case No. 13,041). The full descriptions of these documents are incorporated herein by reference in a manner that is consistent therewith.

With reference to Figures 2 and 2A, the second layer region portion 50 may include a mass or matrix of hydrophilic fibers, such as wood pulp fibers, and a selected amount of the superabsorbent gelation material, such as the pulp. of wood Coosa 1654 and superabsorbent Favor 880 of Stockhausen. These materials will typically be mixed or otherwise combined so that about 20-80% by weight of the compound is comprised of superabsorbent particles. Modifications to this material can also be made to provide improved product performance. These modifications may include the use of pulp fibers or modified to generate improvements in the distribution of the liquid, or the use of stabilization technique to control the structure and generate improved transport performance. Potential stabilization methods include but are not limited to the use of binder material, such as Kymene, or some other crosslinking agent, or the introduction of heat activated binder fibers. The stabilization of structure is a technology used to maintain the structure or minimize changes in the structure of a material or a composite of materials when the materials are exposed to external or internal forces. Various techniques such as the incorporation of thermoplastic binder fibers, chemical crosslinking agents (such as Kymene) and the like, as well as combinations thereof, can be employed to stabilize the absorbent structures.

Any material which is operatively configured with the ability to provide an improved distribution of liquid out of the target area can provide the desired functional results. These materials may be composed of a laminate which includes superabsorbent particles and at least one fibrous web which is particularly configured to exhibit improved transmission flow performance. Suitable arrangements of the second layer region 50 may include, but are not limited to, laminations of fibrous or particulate superabsorbent fabrics with cellulose tissue materials, or any another stabilized fibrous fabric. Other suitable fibrous fabrics may include wet laid tissue, air laid materials incorporating short natural and synthetic fibers, or treated melt blown fabrics, as well as the types of fibrous fabrics used to construct the first layer region. 48. Another class of materials which can be used to provide the improved functionality are the superabsorbent particle laminates or fibrous and wettable fabrics, the open cell foams.

The second layer region 50 may be placed in several suitable configurations. For example, the second layer region may be placed in the form of a separately provided absorbent pad which is immediately placed on one side of the first layer region 48. The second layer region 50 is desirably in an essentially direct contact with the first layer region 48, but alternatively, it can be placed spaced from the upper layer region with one or more layer regions or a selected material interposed between the first region. layer 48 and the second layer region 50. In particular aspects of the invention, the second layer region 50 is configured to allow a maximum use of the absorbent to the incoming liquid while also maintaining pleasing product attributes to the consumer.

In additional aspects, the second primary cap region may have a longitudinal extension which is may than a longitudinal extension of said first primary layer region. Additionally, the second primary layer region may have a lateral extension which is essentially coterminous with said first primary layer region. The alternate configurations may include a second primary layer region which has a lateral extension which is smaller than a lateral extension of said first primary layer region. For example, the lateral extent of at least a portion of the second primary layer region may not be less than about 30% of the lateral extent of an adjacent portion correspondingly of the first primary layer region. Other configurations may include a second primary layer region which has a lateral extension which is greater than a lateral extension of the first primary layer region. For example, the lateral extent of at least a portion of the first primary layer region may not be less than about 30% of the lateral extent of an adjacent portion correspondingly of the second primary layer region.

The component materials in the second layer region 50 can be provided in various operating quantities, base weights, densities, etc. For example, the second primary layer region can have an essentially uniform basis weight or desirably, a selected non-uniform basis weight. Additionally, the second layer region 50 may constitute about 25% -100% of the overall composite weight basis of the absorbent core structure at any location, and may typically have a density in the range of about 0.1 g / cc a 0.3 g / cc. In still other aspects, the second layer region part 50 may include a plurality of two or more component sublayer regions, wherein each of the component sublayer regions has a selected combination of physical and functional characteristics.

In particular aspects of the invention, at least one of the layer regions of the absorbent core 30 is a distributor layer which can provide a Potential Liquid Transmission value of not less than about 16%. In addition, the distributing layer has a perimeter and area boundary that extends beyond and past the designated target region 52 of absorbent compound.

The distributing layer can advantageously provide particular important functions. A first function includes the retention and movement of the liquid out of the target area, and a second function is to provide a sufficiently short term superabsorbent capacity (during liquid discharge) to compensate for the lack of associated void volume with the Executions of the thin product. The structural elements of the layer region include the superabsorbent polymer content, the component basis weights and the component densities. Examples of materials with high liquid transmission performance are described in U.S. Patent No. 5,350,370 entitled ABSORBENT COMPOUND OF HIGH TRANSMISSION LIQUID, and granted on September 27, 1995 to D.M. Jackson and others, whose complete description is incorporated herein by reference in a manner that is consistent therewith.

The second layer region 50 may provide a bottom layer, and may typically extend over the entire area of the general absorbent matrix 30. The second layer region 50 is typically designed to provide the volume of distribution or transmission capacity of the absorbent matrix, and therefore typically will extend further and past the terminal edges of the covered area by the first layer region 48. Within the target area 52 of the absorbent matrix, the second layer region typically may have a basis weight of not less than about 100 grams per square meter, and desirably may have a basis weight of not less than about 150 grams per square meter. In additional aspects, the target area of the second layer region typically can have a basis weight of no more than about 700 grams per square meter and desirably have a basis weight of no more than about 250 grams per square meter. In the non-target parts which are outside the target area of the second layer region 50, the second layer region typically can have a basis weight of not less than about 300 grams per square meter, and can desirably be have a basis weight of not less than about 450 grams per square meter. In additional aspects, the non-target portions of the second layer region which are outside the target area can typically have a basis weight of no more than about 800 grams per square meter, and desirably have a basis weight of no more than about 550 grams per square meter.

The second layer part typically includes not less than about 50% fibrous material by weight, and desirably includes not less than about 60% fibrous material. In other aspects, the second layer part typically can include no more than about 95% fibrous material, and desirably can include no more than about 70% fibrous material. The fibrous material can be natural or synthetic in nature. The fibrous material may have a fiber size, particularly a fiber diameter, of at least about 4 microns and desirably has a fiber size of at least about 10 microns. In additional aspects, the fibrous material may have a fiber size of no more than about 20 microns, and desirably has a Fiber size of no more than about 15 microns. In addition, the fibrous material may be at a contact angle with water of no more than about 70 degrees and desirably has a contact angle with water of no more than about 50 degrees.

The second layer part may also contain not less than about 5% of the superabsorbent material, by weight, and desirably contains no less than about 15% superabsorbent. In additional aspects, the second layer part may include no more than about 50% superabsorbent material, and desirably may include no more than about 40% superabsorbent. The superabsorbent material can have a dry particle size of not less than about 110 microns, and desirably has a dry particle size of not less than about 300 microns. In other aspects, the superabsorbent material may have a dry particle size of no more than about 1000 microns, and desirably may have a dry particle size of no more than about 700 microns. The superabsorbent material may also have a modified absorbency value under a load of not less than about 20 g / g, and desirably may have a modified absorbency value under a load of not less than about 25 g / g. Additionally, the modified absorbency value under load may be up to about 30 g / g, or more, to provide the improved benefits. In still other aspects, the superabsorbent material may have a Tau value of less than about 0. 67 minutes, and may desirably have a Tau value of at least about 2 minutes.

Advantageous embodiments of the invention may include a second layer region 50 which has a potential for transmission of fluid at least about 36% value and contains a superabsorbent having a Tau value of not less than about 0.4 minutes. Other advantageous arrangements may include a second layer region which has a Liquid Transmission Potential value of at least about 16% and contains a superabsorbent having a Tau value of not less than about 0.67 minutes.

In particular aspects of the invention, the superabsorbent material in the first layer region 48 is configured to have a Tau value which is around the Tau value of the superabsorbent located in the second layer region 50 (Tau value ratio of 2: 1) . The proportion of value Tau may alternatively be at least about 2.5: 1, and optionally may be at least about 3: 1 to provide the desired characteristics. In additional aspects, the combination of superabsorbent materials in the first and second layer regions can be configured to provide a Tau value ratio of up to 10: 1, and respectively, the combination of superabsorbent materials it can be configured to provide a Tau value ratio of up to about 40: 1 or more.

The second layer region 50 can typically have an average density of at least about 0.1 g / cc, and desirably have a density of at least about 0.15 g / cc. In other aspects, the second layer region may have an average density of no more than about 0.3 g / cc and desirably may have a density of no more than about 0.25 g / cc. In particular aspects, the average density can be around 0.2 g / cc. The second layer region includes any layers of tissue which are used to hold together the materials placed in the second layer region or which act as a carrier mechanism. For example, several layers of tissue may be employed to contain a layer of superabsorbent material which is laminated between the layers of tissue.

In particular aspects of the invention, at least one of the primary layer regions includes a laminate having one or more layers of a liquid permeable material 100 which operates as a distribution material, such as the layers of a sheet material no creped drying through air (UCTAD). For example, the sheet material can be a fibrous tissue, and the desired configurations can incorporate the sheet material dried through non-creped air in the second primary layer region of the absorbent matrix.

The non-creped air-dried materials can provide a transmission property characterized by a liquid flow, at a height of 15 cm which is at least 0.002 grams of liquid per minute per base weight of 1 g / m2, by an inch of material width. The material dried through non-creped air has a basis weight of at least about 50 g / m2, and has a density within the range of about 0.08-0.5 g / cc. Desirably, the density is within the range of about 0.1-0.3 g / cc. The permeability of the dried sheet material through non-creped air is within the range of about 50-1000 darcies. The non-creped air dried sheet material has a dry tensile strength of at least 5000 grams of force per one inch of folded material at a basis weight of 200 g / m2.

The non-creped air-dried sheet materials are described in United States Patent Application Serial No. 08 / 767,645 filed on December 17, 1996 by J. Dutkiewicz et al. And entitled ABSORBENT STRUCTURE FOR THE DISTRIBUTION OF LIQUID (attorney's matter No. 12,267), whose complete description of which is incorporated herein by reference in a manner that is consistent therewith.

With reference to Figure 8, the second primary layer region 50 may include a composite which includes an assembled heterogeneous plurality of sublayer sections 62 and 64. In the illustrated configuration, for example, a first sublayer section 62 may extend over essentially the entire area covered by the absorbent matrix 30, and a pair of second sub-layer sections 64 spaced apart and spaced apart are placed on one side of the body-side surface of the first sub-layer section 62, with each of the second sublayer sections extending over a selected part of the general surface area of the absorbent core 30. The configuration shown has the second sublayer sections 64 longitudinally spaced apart, and as illustrated, each of the sublayer sections 64 may have a end edge which is essentially coterminous with its associated longitudinal end of the absorbent matrix 30. C As a result, the second primary layer region 50 may have a zoned base weight distribution, with a longitudinal middle part having a basis weight which is lower than a basis weight of two longitudinally opposite end portions of the layer region. 50 primary In particular aspects of the invention, at least one of the sublayer sections may include a laminate having one or more layers of the dried sheet material through non-creped air (UCTAD), such as the dried sheet material tissue. through non-creped air. For example, the desired configurations may include a first sublayer region 62 of the absorbent matrix wherein at least one pair cooperating layers of the sheet material dried through non-creped air are constructed and arranged to have a sandwich in the form of a sandwich. distributed layer of superabsorbent particles 102 therebetween. Additional layers of the distribution material, such as additional layers of the sheet material dried through non-creped air, may be employed to additionally have the superabsorbent particle layer 102 within the first sublayer 62 as a sandwich, as shown representatively in figure 8.

In additional aspects, either or both of the sublayer sections 64 may include at least one cooperating pair of layers of sheet material dried through non-creped air and arranged to have a distributed layer of superabsorbent particles in the form of a sandwich. same. Additional layers of the distribution material, such as additional layers of sheet material dried through non-creped air, can be used to have a sandwich shape additionally the layer of superabsorbent particles therebetween within the second sublayers 64.

With reference to Figure 9, the second sublayer region 50 may alternatively include a compound in which the base weight distribution of the superabsorbent particles is essentially zoned to provide a variable basis weight, particularly along the longitudinal direction of the second primary layer region 50. As a result, the second primary layer region 50 can have a zoned, super-absorbent base weight distribution, with a longitudinal middle part of the layer region 50 having a basis weight of superabsorbent which is more under a basis weight of the superabsorbent distributed in two longitudinally opposite end portions of the second primary layer region 50. Further descriptions of the various configurations of the invention are provided in the United States patent application Serial No. 09 / 096,652 by R. Everett et al., Entitled ABSORBENT STRUCTURE IN LAYERS, and p filed on June 12, 1998 (attorney's case No. 13,505); in the application of the United States of America Series No. 09 / 097,285 of R. Everett et al., entitled ABSORBENT STRUCTURE IN LAYERS WITH A ZONED BASE WEIGHT, and filed on June 12, 1998 (attorney's issue No. 13,506); and in the United States of America patent application Series No. 09 / 096,653 by R. Everett et al., entitled STRUCTURE ABSORBENT IN LAYERS WITH A HETEROGENIC LAYER REGION, and filed on June 12, 1998 (attorney's issue No. 13,507), whose full descriptions of each of these documents are incorporated herein by reference in a manner that is consistent therewith .

Referring again to FIG. 1, the leg elastics members 34 are located on the side side margins 110 of the diaper, and are arranged to pull and hold the diaper 20 against the wearer's legs. The elastic members are secured to the diaper 20 in an elastically contractible condition so that in a normal tensioned configuration, the elastic members contract effectively against the diaper 20. The elastic members may be secured in an elastically contractible condition in at least two way, for example, the elastic members can be stretched and secured while the diaper 20 is in an uncontracted condition. Alternatively, the diaper 20 can be contracted, for example, by folding and the elastic members secured and connected to the diaper 20 while the elastic members are in their relaxed or unstretched condition. Still other mechanisms, such as heat-shrinkable elastic material, can be used to fold the garment.

In the embodiment illustrated in Figure 1, the elastic leg members 34 extend essentially as far as length of the full length of the intermediate crotch region 42 of the diaper 20. Any alternative elastic members 34 may extend to the full length of the diaper 20, or any other suitable length providing the arrangement of elastically contractible lines desired for the particular diaper design. .

The elastic members 34 can have any of a multitude of configurations, for example, the width of the individual elastic members 34 can be varied from about 0.25 millimeters to about 25 millimeters or more. The elastic members may comprise a single strand of elastic material, or may comprise several parallel or non-parallel strands of elastic material, or may be applied in a curvilinear or rectilinear arrangement. Where the threads are non-parallel, two or more threads may intersect or otherwise interconnect with the elastic member. The elastic members can be fixed to the diaper in any of several ways which are known in the art. For example, the elastic members can be ultrasonically bonded, sealed with heat and pressure using a variety of bonding patterns, or adhesively attached to the diaper 20 with spray or swirl patterns of an adhesive, such as a melt pressure sensitive adhesive. hot In the particular embodiments of the invention, the elastic leg members 34 may include a carrier sheet on which are attached a set of elastics composed of a plurality of individual elastic threads. The elastic threads may intersect or interconnect or may be completely separated from each other. The carrier sheet may, for example, comprise a 0.002 cm thick polymer film, such as a film of non-etched polypropylene material. The elastic yarns can, for example, be composed of a LYCRA elastomer available from DuPont, a business having offices in Wilmington, Delaware. Each elastic yarn is typically within the range of about 470-1500 decitex (dtx) and can be around 940-1050 decitex. In the particular embodiments of the invention, for example, three or four threads may be employed for each elasticized leg band.

In addition, the leg elastics 34 may be generally straight or optionally curved. For example, the curved elastics can be arched inward toward the longitudinal centerline of the diaper. In particular arrangements, the curvature of the elastics may not be configured or placed symmetrically in relation to the lateral center line of the diaper. The curved elastics can have an arched inward and an arched outward, reflective type of curvature, and the longitudinal center of the elastics can be optionally offset by a selected distance toward and be the front or back diaper waistband to provide the desired fit and appearance. In the particular embodiments of the invention, the innermost point (apex) of the set of curved elastics can be offset towards the front or back waistband of the diaper, and the reflected portion arched towards the front can be placed towards the front waistband of the diaper.

As shown representatively, the diaper 2 may include a waist elastic 32 placed on the longitudinal margins of either or both of the front waistband 3 and the waistband waistband 40. The waist elastics may be composed of any suitable material, such as an elastomeric film, an elastic foam, multiple elastic threads, an elastomeric fabric or the like. For example, suitable elastic waist constructions are disclosed in U.S. Patent No. 4,916,005 to Lippert et al., The complete disclosure of which is incorporated herein by reference in a manner consistent therewith.

The diaper 20 may also include a pair of elasticized restraining flaps 82 which extend generally longitudinally along the longitudinal direction 86 of the diaper. The containment fins are typically placed laterally inward of the elastics of leg 34 and are symmetrically placed on each side of the longitudinal centerline in the direction of the diaper length. In the illustrated arrangements, each containment flap 82 has an essentially fixed edge portion 81 and an essentially movable edge portion 83, and is operably elasticated to assist each containment flap to conform to and make close contact with the body contours of the body. user. Examples of suitable containment fin constructions are described in U.S. Patent No. 4,704,116 issued November 3, 1987 to K. Enloe, the complete description of which is incorporated herein by reference in a way that is consistent with it. The containment fins may be composed of a wettable or non-wettable material, as desired. In addition, the containment fin material may be essentially impermeable to the liquid, may be permeable only to the gas or may be permeable to both the gas and the liquid. Other suitable containment fin configurations are described in U.S. Patent Application Serial No. 206,816 to R. Everett et al., Filed March 4, 1994 and entitled ABSORBENT ARTICLE WHICH HAS IMPROVED EMERGENCY MANAGEMENT, (Attorney's Issue No. 11,375), which was granted as United States of America Patent No. 5,562,650, the disclosure of which is incorporated herein by reference in a manner that is consistent therewith.

* ,. In alternative configurations of the invention, the diaper 20 may include the elasticated waist flaps, such as those described in United States Patent No. 4,753,646 issued June 28, 1988 to K. Enloe and in the Application of the United States of America Series No. 560,525 of D. Laux et al., entitled AN ABSORBENT ARTICLE WITH IMPROVED ELASTIC MARGINS AND THE CONTAINMENT SYSTEM, and filed on December 18, 1995 (attorney's case No. 11,091); whose full descriptions are incorporated herein by reference in a manner that is consistent therewith. Similar to the constructions of the containment fins, the waist fins may be composed of a wettable or non-wettable material as desired. The waist flap material can be essentially liquid impervious, permeable only to gas, or permeable to both gas and liquid.

To provide a resilient fastening system, the diaper 20 can include a designated location area 78 (e.g. Figure IA), which can provide an operable lens area for receiving a releasable fastener appendage 44 thereon. . In the particular embodiments of the invention, the placement zone patch can be placed on the outer surface of the lower sheet layer 22 and is located on the front waistband portion 38 of the diaper. The clamping mechanism between the positioning area and the fastener appendages 44 can be adhesive, cohesive, mechanical or combinations thereof. A configuration which employs a releasable interengangable mechanical fastening system can, for example, locate a first part of the mechanical fastener on the positioning zone 78 and a second cooperating portion of the mechanical fastener on the fastening tab 44. For example, with the fastener of hook and loop the hook material 46 can be operably connected to the fastener appendages 44 and the loop material 80 can be operably connected to the collocation zone 78. Alternatively, the loop material can be operably connected to the fastening appendages 44 and the Hook material can be connected operably to the laying area.

In the various embodiments of the invention, a tape fastener tab 44 may be located on either or both of the side end regions 116 and 118 of either or both of the waistbands 38 and 40. The embodiment shown representatively, for example, it has the fastener appendages 44 located on the distal side edges of the rear waistband 40. Furthermore, the bottom sheet layer 22 can have a designated fastener location area 78 positioned on an outer surface of the bottom sheet layer.

With reference to Figure 1, for example, the article may include a system of side panel members 90. In particular arrangements each side panel member 90 extends laterally from opposite side ends of at least one waistband part of the body. bottom sheet 22, as representatively shown in the rear waistband portion 40, to provide the terminal side sections of the article. In addition, each side panel can extend essentially from a laterally extending end waistband edge 106 to approximately the location of its corresponding and associated leg opening section of the diaper. The diaper 20, for example, has a pair of laterally opposed leg openings formed by the designated middle sections of the shown pair of longitudinally extending side edge regions 110 (Figure 1). Each side panel may extend at a longitudinal distance of at least about 4 cm, optionally it may extend at a longitudinal distance of at least about 5 cm and alternatively it may extend at a distance of at least about 6 cm. cm to provide an improved notch.

In the various configurations of the invention, the side panels can be formed integrally with a selected diaper component. For example, side panels 90 can be integrally formed of the layer material that provides the bottom sheet layer 22 or can be formed integrally of the material used to provide the top sheet 24. In the alternative configurations, the side panels 90 can be provided by one or more separate members that are connected and assembled to the bottom sheet 22, to the top sheet 24, between the bottom sheet and the top sheet, and the various combinations fixedly fixed of such assemblies.

In particular aspects of the invention, each of the side panels 90 can be formed from a separately provided piece of material which is then assembled suitably and fastened to the selected front and / or back waistband portion of the diaper article. In the illustrated embodiments of the invention, for example, each side panel 90 is attached to the rear waistband portion of the bottom sheet 22 along a side panel fastening region 94, and can be operably fastened to either or both of the lower leaf and upper leaf components of the article. The configurations shown have the region of the inner fastening region of each side panel superimposed and laminated with the corresponding lateral end edge region of the waist band section of the article. The side panels extend laterally to form a pair of opposite waist flap sections of the diaper, and are fastened with suitable connecting means, such as adhesive bonding, thermal bonding, ultrasonic bonding, staples, sewing or the like.

Desirably, the side panels extend laterally beyond the terminal side edges of the bottom sheet layer and the top sheet layer in the attached waistband section of the article.

The side panels 90 can be composed of an essentially non-elastomeric material such as polymer films, woven fabrics, non-woven fabrics and the like, as well as combinations thereof. In particular aspects of the invention, the side panels 90 are composed of an essentially elastomeric material, such as the stretched-bonded-laminate (SBL) material, a laminate-bonded (NBL) material, an elastomeric film, a material of elastomeric foam or the like, which is elastically stretchable at least along the lateral direction 88. For example, meltblown elastomeric fibrous fabrics suitable for forming the side panels 90 are described in US Pat. North America No. 4,663,220 issued May 5, 1987 to T. Wisneski et al., The full disclosure of which is incorporated herein by reference. Examples of composite fabrics comprising at least one layer of a non-woven textile fabric secured to a fibrous elastic layer are described in European Patent Application EP 0 217 032 A2 published on April 8, 1987, which has the inventors listed as J. Taylor et al., whose full description of which is incorporated herein by reference.

Examples of laminate-bonded-laminate materials are described in United States Patent No. 5,226,992 issued July 13, 1993 to Mormon, the complete disclosure of which is incorporated herein by reference.

As mentioned previously, various suitable constructions may be employed to join the side panels 90 to the selected waistband portions of the article. Particular examples of constructions suitable for securing a pair of resiliently stretchable members to the lateral side portions of an article to extend laterally further outward from the laterally opposite side regions of the outer cover and liner components of a can be found in U.S. Patent No. 4,938,753 issued July 3, 1990 to P. VanGompel et al., the full disclosure of which is incorporated herein by reference in a manner that is consistent with the same Where the side panels 90 are composed of a material which has been elastized or otherwise constructed to be elastomerically stretchable, the elastomeric side panels may desirably provide an elongation to the peak load of at least about 30% when undergo a tensile force load of 0.33 pounds per linear inch of the same sample dimension that is measured perpendicular to the direction of the applied load (around 0.58 Newtons / cm). Alternatively, the elastomeric side panel material can provide an elongation of at least about 100% and optionally can provide an elongation of at least about 300% to provide improved performance.

Each of the side panels 90 extends laterally from the opposite side ends of at least one waistband section of the diaper 20. In the embodiment shown, each side panel extends laterally from the opposite side ends of the rear waistband section of the diaphragm. the lower sheet 22. Each of the side panels includes a relatively outer terminal free end region 92 which has a longitudinally extending length dimension. Each side panel also has a width dimension and a base region fastening region 94 which has a construction joint attached to either or both of the top sheet and backsheet layers. The side panels may have a contoured or tapered shape in which the base length of the fastening zone of the side panel 94 is longer than the length of the relatively outer distal end region 92. Alternatively, the length of the area of Clamp 94 may be smaller than the length of the relatively outer distal end region 92.

Optionally, the side panels may have an essentially rectangular shape or an essentially trapezoidal shape.

A tension beam section 98 can be constructed on each of the side panels 90 along its free end region 92 to more evenly distribute stress stresses through the side panel area. The tension beam section is configured with a relatively high stiffness value and in the desired configurations, the tension beam section extends along essentially the entire longitudinal extent of the outer region of side panel 92. An attachment appendix 44 may be connected to extend laterally from the tension beam section of each of the side panels 90 to secure the waistband sections of the article around a user during the use of the article.

Each fastening tab 44 may include a carrier layer 56 which interconnects an inner edge region of the selected fastening component, such as the hook member shown 46, to the outer edge region of its corresponding and associated side panel 90. carrier layer has a first lateral region laterally inwardly and a second lateral region laterally outwardly. The first side region is laminated, or is connected to another and fixed to the side panel with an operable construction joint.

The side panel material, the carrier layer layer and the construction joint configuration are constructed and arranged to form the operating tension beam section 98. Optionally, an additional layer of the reinforcing material can be included along the length of the tension beam region to increase the stiffness of the beam and to further improve its ability to spread stresses along the longitudinal dimension of the side panel. The inner region of the carrier layer 56 may have a longitudinal extension which is smaller than the longitudinal dimension of the outer free edge portion 92 of the side panel 90. Alternatively, the carrier layer 56 may have a longitudinal extension which is essentially the same a (for example, figure 1) or greater than the longitudinal dimension of the outer part of the side panel.

The hook material member 46 is laminated or otherwise connected and fixed to the outer region of the carrier layer with an operable construction fastener. In particular, the hook material shown 46 is laminated to a side surface to the inner body of the carrier layer with the hook elements extending generally into the article. With the illustrated arrangement, the outer lateral distal edge of the second carrier edge region is coterminous with the laterally outer distal edge of the hook member 46. Alternatively, the laterally outer distal edge of the second carrier edge region may be spaced laterally inward from the terminally distal end edge of the hook member 46. In any configuration, the laterally distal edge of the hook member 46 provides the laterally terminal edge of the article.

The relatively longitudinally extending outer edge of the side panel member 90 can be spaced from the relatively longitudinally extending, longitudinally extending edge of the selected holding region by a spacer spacing of the carrier. More particularly, the outer edge of the side panel member 90 can also be spaced from the relatively inner edge of the hook member 46 by a spacer spacing of the carrier. The spacer distance optionally has a lateral extension which is equal to or greater than the lateral extension of the holding region. In addition, the side-to-body surface facing inward of the carrier layer 56 is constructed to have limited mechanical inter-engagement with the hook elements. As a result of this, the fastening tab 44 can be bent along a longitudinally extending fold line to selectively locate and configure the fastening region in a storage position with the hook elements positioned and held against the fastener. side-to-body surface of the carrier layer 56. The level of engagement between the hook material and the carrier layer requires only enough to maintain the storage position. By example, the hitch can provide a single peak peel strength value within the range of about 1-50 grams of force.

In the particular configurations of the invention, the carrier layer material 56 may be composed of an essentially non-elastomeric material, such as polymer films, woven fabrics, non-woven fabrics or the like, as well as combinations thereof. Alternatively, the carrier fabric material may be composed of an essentially elastomeric material, such as a stretched-bonded-laminate (SBL), a laminated-bonded (NBL) material, an elastomeric film, an elastomeric foam material, or similar, as well as combinations thereof. The elastomeric material is elastomerically stretchable at least along the lateral direction 88. For example, the carrier fabric material may be composed of a spunbond-melt-spunbonded (SMS) web having a core of meltblown fibers sandwiched between two face layers of spunbonded fibers to provide a total composite basis weight within the range of about 50-67 g / m2 (about 1.5-2 ounces / square yard). As another example, the carrier fabric material can be completely composed of a non-woven spunbonded fabric having a basis weight within the range of about 50-67 g / m2 (about 1.5 2 ounces / square yard).

Mechanical fasteners cooperatively employed with the various configurations of the invention can be provided by mechanical fasteners such as hooks, buckles, boteroles, buttons and the like, which include mechanical and complementary interlocking components. In particular aspects of the invention, the fastening means may be provided by a hook and loop fastener system, a mushroom and curl fastening system or the like (collectively referred to as hook and loop fasteners). Such fastening systems generally comprise a male hook-type component and a female curl-type cooperating component which engages and interconnects releasably with the hook component. Desirably, the interconnection is selectively releasable. Conventional systems, for example, are available under the VELCRO brand.

Examples of suitable hook and loop fastening systems are described in U.S. Patent No. 5,019,073 issued May 28, 1991 to T. Roessler et al., The description of which is incorporated herein. by reference in a way that is consistent with it. Other examples of fastening systems hook and curl are described in the patent application of the United States of America Series No. 366,080 entitled "HIGH-FELT APPENDIX BRAS", filed December 28, 1994 by G. Zehner et al. (attorney's case No. 11,571), which was granted as the patent of the United States of America No. 5,605,735; and U.S. Patent Application Serial No. 421,640 entitled MULTIPLE UNION CLAMPING SYSTEM, filed April 13, 1995 by P. VanGompel et al .; whose complete descriptions of which are incorporated herein by reference in a manner that is consistent therewith. Examples of fastening appendages constructed with a carrier layer 56 are described in United States Patent Application Serial No. 08 / 603,477 to A. Long et al., Entitled MECHANICAL CLAMPING SYSTEM WITH GRIP APPENDIX, and filed on March 6, 1996 (attorney's issue No. 12,563), which was issued as United States of America Patent No. 5,624,429 whose full disclosure is incorporated herein by reference in a manner that is consistent with the same In a typical configuration of a hook and loop fastening system, the hook material member 46 is operably connected to the holding tab 44 and the loop material 80 is employed to construct at least one cooperating engaging zone 78. area of placement, for example, can be placed properly on the surface of exposed outer side of the lower sheet 22. As previously mentioned, an alternative configuration of the hook and loop fastening system may have the loop material secured to the fastening tab 44 and may have the hook material used to form the fastening area. placement 78.

In particular aspects of the invention, the hook material member 46 can be of the type mentioned as the micro-hook material. A suitable micro-hook material is distributed under the designation CS200 and is available from 3M Company, a business having offices in St. Paul, Minnesota. The micro-hook material can have hooks in the form of "mushroom caps", and can be configured with a hook density of about 1600 hooks per square inch; a hook height which is within the range of about 0.033-0.097 cm (about 0.013 to 0.038 inches); and a lid width which is within the range of about 0.025-0.033 cm (about 0.01 to 0.013 inches). The hooks are attached to a base film substrate having a thickness of about 0.0076-0.01 cm and a Gurley stiffness of about 15 mgf (milligrams-force).

Another suitable micro-hook material is distributed under the designation VELCRO CFM-29 1058, and is available from VELCRO USA, Inc., a business having offices in Manchester, New Hampshire. The micro-hook material can having hooks in the form of angled hook elements and can be configured with a hook density of about 264 hooks per square centimeter (about 1700 hooks per square inch); a hook height which is within the range of about 0.030-0.063 cm (about 0.012-0.025 inches); and a hook width which is within the range of about 0.007 to 0.022 cm (about 0.003 to 0.009 inches). The hook elements are co-extruded with a base layer substrate having a thickness of about 0.0076-0.008 cm (about 0.003-0.0035 inches) and the hook material member has a Gurley stiffness of about 12 mgf (12 units) Gurley).

For the purposes of the present invention, the various stiffness values are determined with respect to the bending moment produced by a force which is directly perpendicular to the plane essentially defined by the length and width of the component being approved. A suitable technique for determining the stiffness values described herein is a Gurley stiffness test, a description of which is established in the TAPPI standard test T 543 om-94 (Resistance to Paper Folding (Gurley type tester)). A suitable test apparatus is a Gurley digital stiffness tester; Model 4171-D manufactured by Teledyne Gurley, a business having offices in Troy, New York.

In the various configurations of the invention, the terry material can be provided by a nonwoven, woven or woven fabric. For example, a fabric of suitable curl material may be comprised of a two-bar warp knitted fabric of the type available from Guilford Mills, Inc., of Greensborough, North Carolina under the trade designation # 34285, as well as other of woven fabrics. Suitable curl materials are available from 3M Company, which has a nylon knit loop distributed under its SCOTCHMATE brand. 3M Company has also distributed an unlined terry cloth with adhesive on the underside of the fabric, and the 3M woven terry ribbon.

In particular aspects of the invention, the curl material may not be limited to a patch of discrete placement zone. Instead, the loop material can, for example, be provided by an essentially continuous outer fibrous layer which is integrated to extend over essentially the entire exposed surface area of the fabric-type outer cover employed with the diaper 20. The resulting fabric type backing sheet 22 can therefore provide the curl material for a mechanical "holding on either side" fastening system operative. As a practical matter, the area extension of the curl material will depend on the cost of the material.

The fastening elements in the various constructions of the invention can be operably joined to their base layer by employing one or more or more of the fastening mechanisms employed to construct and hold together the various other components of the article of the invention. Desirably, the fastening elements in the various fastening regions can be integrally formed, such as by molding, co-extrusion or the like, together with the associated base layer. The base layer and the mechanical fastening elements can be formed of essentially the same polymer material, and do not require a discrete step of fastening the joining elements to an initially separate hook base layer. In the configurations shown representatively of the primary fastening region, for example, the hook elements can be integrally formed simultaneously with the hook base layer by co-extruding the base layer and the hook elements from essentially the same material of polymer.

It should be readily appreciated that the strength of the fastener or other interconnection between the base layer and the attached fastening component must be greater than the peak force required to remove the fastening tab 44 from its releasable fastener to the designated positioning area of the article.

Testing and Calculation Procedures Partial Saturation Thickness Procedure The thickness height (h) of each layer in its partially saturated state can be determined by using the new entries as determined above and the following procedure: Scope: The thickness (h) of each layer region in a partially saturated state was determined.

Equipment and materials Glass petri dish (100 x 15 mm-Corning Number 3160-101- Number of Scientific Fisher Catalogs 08-747C).

Blood bank salt water solution, such as blood bank salt water catalog No. 8504, obtained from Stevens Scientific, a division of Cornwell Corporation, a business having offices located in Riverdale, New Jersey, or a substantial equivalent.

Thickness tester with a 0.05 psi (0.345 KPa) plate of 7.62 cm in diameter.

Cutter of matrix - circle of 7.62 cm.

Heavy Scale Laboratory Stopwatch Test Procedure Cut with matrix a 7.62 cm diameter sample of the material to be tested.

Calculate the saturation (sample grams / fluid grams) of the layer based on a saturation of 0.6 g / cm2 of the absorber and the superabsorbent mass, using the technique discussed in the calculation of flow conductance.

Weigh the dry sample and record the weight.

Calculate the amount of liquid salt water solution to be added to the sample by multiplying the weight of the dry sample by the desired saturation level.

Fill the calculated amount of liquid in a petri dish on the flat surface to provide an even distribution of the liquid to the sample.

Place the sample in the petri dish so that the sample remains flat. Start the chronometer.

After 30 minutes have passed, remove the sample from the petri dish.

Measure the thickness of the sample (in mm) below a restriction pressure of 0.05psi 0.34 KPa and record the thickness. The values of the height (h) of partial saturation thickness can be used in the equation used to calculate the Flow Conductance Value for the absorbent compound system.

Calculation of Flow Conductance The flow conductance of the absorbent core at a liquid loading of 0.6 g / cm 2 of absorbent was used to reflect the capture capacity of the absorbent core structure when the core is in its partially saturated state. The flow conductance can be described by the following equation: Flux Conductance Value = Kjhj + K2h2 + K3h3 + where : K = the permeability of each layer at a given saturation. h = the thickness of each layer at a given saturation The permeability (K) of each layer in the core can be computed as follows: each layer in the absorbent core is a combination of essentially non-swelling fibers and superabsorbent particles, fibers or flakes.

The expressions for the permeability of a collection of cylinders oriented randomly and for a collection of spheres are: For the forms of elongated cylindrical fibers and other regular and irregular fibers: For the forms of generally spherical and other regular or irregular particles: I? S 0.3555 K = (1 -te) «ÍJ where SA /? is the ratio of volume to surface area d of the solid part in centimeter 1 and porosity, e, is the ratio of the pore volume to the total volume of the complete medi. The basis for the permeability expressions given above comes from Happel and Brenner Hydrodynamics by Númer Reynolds Bajo, from Noordhoff International Publishing (1973). The permeability expressions for the permeabilide cylinders for the cylinders and spheres derived in that work were adjusted to simpler forms, as shown above, to obtain value of the exponent and the multiplier.

It has been observed that essentially all the liquid delivered during the first discharge is imbibed by the superabsorbent before the second discharge is delivered. Therefore, for the purpose of calculating the permeability value used in flow conductance computations, all of the above-specified liquid (0.6 g / cm2) was considered to be within the superabsorbent. Therefore, in the calculation of the values for porosity, e, and the proportions of surface area by volume for the superabsorbents, the liquid volume is included as part of the solid volume. Therefore, the porosity of the material is given by: € = 1- [(solid volume + liquid volume) / (total volume occupied by the moistened sample)]; where the total volume occupied by the wetted sample was determined by the area of the sample multiplied by the thickness of the sample. The thicknesses of the sample can be determined by a partial saturation thickness method, established in the following description.

The terms of surface area by volume (SA / V) used in the permeability equations for the various components are calculated using the surface area by volume expressions for any fibers or particles, as appropriate for the morphology of the individual component. . For fibers, the ratio of surface area volume is equal to the ratio of perimeter area, p / of the cross section taken perpendicular to the longitudinal axis of the cylinders. For a cylinder with a circular cross section, for example: SA /? = / a = 2 / r; where r is the radius of the cylinder cross section in centimeters.

For tape type forms; for example, with an approximately rectangular cross section: SA / V = p / a = 2. (width + thickness) / (width thickness) Fibers with more complex cross-sectional shapes, perimeter to area proportions, can be determined by microscopic techniques well known in the art. For example, see E.E. Underwood, Quantitative Stereology, Addison Esley Publishing Co. (1970). In these computations, the ratio of surface area to volume of essentially non-swelling fibers can be determined by using an "SA / V" value (for the ratio of surface area of the fiber to volume), which is appropriate for that way in cross section of the fiber. For example, the fluff fibers are generally ribbon-like, with a rectangular cross-sectional shape. For a fluff fiber with a thickness of 8 microns (0.0008 cm) and a width of 40 microns (0.0040 cm), for example, the ratio of surface area per volume is SA / V = p / a = 2. (8 + 4 O 'l O-4 / ((fi8. »4400) ,.» 10-8) SA / V = 3000 cm " The morphology of superabsorbent can be particulate, fibrous, flake type or combinations thereof. The swelling characteristics of superabsorbent can also be isotropic or anisotropic. Most commercially available superabsorbents are in the form of particles, which swell essentially isotropically. Such superabsorbent particles can be treated as spheres in the present computations. When the particle sizes are all essentially identical, the ratio of surface area or volume for a sphere can be used to estimate the ratio of surface area to volume of the superabsorbents. The proportion of surface area or volume for a sphere is given by SA /? = 3 / r where r is the radius of the sphere in centimeters However, the superabsorbent materials can be composed of a particle size distribution. When the distribution is essentially monomodal, the surface area of heavy account to volume can be used. For a given distribution, this value can be calculated as follows: where I *, = midpoint of the range of particle radii of the part i ?, in centimeter.

Ili = the number of particles within part i *.

III, = fraction of particle mass inside the part i in grams PSAP = solid density of the dry superabsorbent in g / cc.

If the particle size distribution is multimodal, for example bimodal, a separate permeability for each modal group should be used in the self-consistent calculation of the permeability of the composite material detailed below. In this case, a ratio of surface area to account volume heavy should be calculated for each modal group, as described above. Typically, at least 6 to 8 different particle size fractions should be used to estimate the particle size distribution of the superabsorbent.

The swelling of the superabsorbent with the absorption of the liquid also complicates the process of incorporation of the contributions of the superabsorbent in the determination of the permeability of the compound. In particular, the size and hence the proportion of the surface area or volume of the superabsorbent will depend on the level of saturation of the superabsorbent. The ratio for the ratio of surface area to volume of a superabsorbent particle of isotropic swelling, as a function of its liquid content is where (SA / y) moj ^ ,, = surface area by volume ratio of wet superabsorbent in centimeter'1.

S = saturation of the superabsorbent expressed as grams of liquid per gram of superabsorbent.

PSAP = dry SAP density in g / cc. i = density of the liquid in g / cc.

(SA / y). ^ = Ratio of surface area to volume of dry SAP in centimeter "1.

The superabsorbent materials may also be present in the fibrous form. It has been observed that, in general, the fibrous superabsorbents will swell anisotropically. In particular, the increase in fiber volume with an increased liquid content is primarily radial with the fiber length remaining relatively constant. In such cases, the ratio of surface area volume of the swollen superabsorbent fiber is given by.

With the above-mentioned ratios, the proportion of surface area volume as a function of the liquid content of the superabsorbent, the proportion of the Surface volume for the superabsorbent with a particular liquid content can be calculated. Before the ratio of surface area volume for each superabsorbent can be calculated for use in the permeability equations given above, the saturation level of each superabsorbent in each layer must be determined. The following discussion describes the method used to estimate the level of saturation of each of the absorbers present in the absorbent core.

It has been observed that, in the time interval between the delivery of the first and second liquid discharges to the product, the liquid is essentially completely taken up by the superabsorbents in the system. It has also been observed that the liquid delivers during the first discharge divisions between the superabsorbent materials according to their relative amounts and liquid intake rates. For the liquid loading specified above (0.6 g / cm2), the saturation, Sj, expressed as grams of liquid amount per gram of superabsorbent in each superabsorbent can be calculated as follows: • S. { bw / 10") DWj = base weight of j * superabsorbent e grams / square meter / p i «liquid division factor for t superabsorbent The liquid division factors J p s so calculated for each superabsorbent component based on the rates and relative amounts of the various superabsorbent components. where üW, = base weight of the j? superabsorbent in grams / square meter, J R = relative rate factor of jm superabsorbent The relative rate factor, J R} , for each superabsorbent is given by where T j = time required for the superabsorbent j * absorb 60% of its equilibrium capacity on the no load absorbency test (FAUZL) described here.

For the purposes of illustrating the method, I consider an example having a two-layer absorbent with the following compositions: The layer 1 region: superabsorbent type 1 with a particle size of a heavy count of 400 micras to 120 gsm (grams per square meter), = 5 min, Clears wood pulp at 120 grams per square meter with a fiber cross section of 8 microns per 4 microns, Thickness measured at the saturation level specified below = 0.55 cm The layer 2 region: superabsorbent type 2 d heavy particle particle size from 400 microns to 150 grams per square meter, T 2 = 10 min, Clears wood pulp at 300 grams per square meter with a fiber cross section of 8 microns per 40 microns, Thickness measured at the saturation level specified below = 0.51 cm.

For the superabsorbents used in these layers *. = ^ = 1 1 120 P \ ~ = = 00..62 (1 - 120 + 0 ^ 150) 0.5- 150 J Dt ~ = 0.38 P2 (1- 120+ 0.5- 150) so that _ (0.38- 0.6) 15.2 * / 52 = (150- "*) g The above-mentioned computations are appropriate when the total equilibrium FAUZL superabsorbent capacities are not exceeded at the specified load of 0.6 g / cm2. If the capacity of a particular superabsorbent material is exceeded under these circumstances, its saturation is set at the equilibrium value and the excess liquid is assumed to reside in the other superabsorbents in a manner consistent with the descriptions given herein.

Based on the amounts of liquid located within the superabsorbent particles, the ratio of surface area or volume of the swollen particles or fibers in each layer can be calculated using the appropriate surface area to volume equations given above for the particles and / or swollen fibers. The identified permeability equation for the spheres should be used for particulate superabsorbents, and the identified permeability equation for cylinders should be used for fibrous superabsorbents.

In this particular example the superabsorbents are in the form of particles so that their proportions of surface area or volume when the core contains 0.6 g / cm2 liquid are as follows: Superabsorbent layer region 1 3 / (200 • 10-1) = 41.6 cm-1 [l +. (31 • WJflJ Üí) Superabsorbent of the layer 2 region 3 / (200 • 10") 52.4 cm" The fluff pulp component used in both layers: s - 2 • (8 + 40) • 10 / ((8 • 40) • 10- *) One can put the appropriate equations to determine the permeability of each of the components within each composite layer region used to construct the absorbent core by using the expressions given above for the permeabilities of the fiber collections or the collections of particles. However, the expressions given above for the permeabilities of the collections of fibers and / or particles are valid only if the complete porous medium consists only of monodisperse fibers or particles. When both fibers and particles are present in a medium of specified porosity, the expressions given above are combined. The method used to combine these two, is in accordance with the self-consistency method of lineado in A.L. Berdichevsky and Z Cai, "Performance Predictions of Permeability by the Self-Consistent Method and the Finite Element Simulation" Polymer Compounds, 14 (2), (1993).

For the present description, the basic premise behind the self-consistent method is that the permeability is essentially homogeneous through the porous medium. Therefore, the local porosity values that correspond to the fibers and particles are determined in such a way that their local permeability is equal. The computation given above was subjected to the restriction that the general porosity (e copf) of the structure can be maintained at the specified value, which is determined by the sample area measured and the thickness as described above. The simplest composite composition consists of two components. In this case, two permeability equations will be required for the self-consistent equation of the composite permeability. For the two-layer example present described above, the permeability equations to be used in self-consistent composite permeability computation are as follows: The permeability equations for layer 1 layer 2 are: Layer 1 region Kfibr fiber-, superabsorbent KsAP 1 Layer of Region 2 fiber Kg? b, ra 2 C_a3o_ (l - superabsorbent KSAP2 where epibral '-SAPI' epbra2 AND eSAP2 corresponds to the local porosity values of the superabsorbents and fiber in layers 1 and 2, respectively. The combination of local porosities should give the correct general porosity obtained from the thickness measurements described above, such as b uw rvtl comp • 1 * 0 v " £ Gcomp - 1 l comp where bwt, cotnp = basis weight of the compound in grams per square meter, fk = fraction of mass of the compound provided by fiber K ?; fi = mass fraction of the compound provided by the superabsorbent j1 so that S /, + S /, - =? * j pk = fiber density K *, j = density of superabsorbent j? H.H? = density of the liquid, S. = saturation level of superabsorbent j * e grams per gram of the superabsorbent, tlcop = thickness (centimeters) of the compound a level of the liquid loading equal to the charge of the total liquid of the compound, where the charge of the total liquid in the compuest is given by: bwtcomp- 104 ' For the example of two layers given above with only one type of fiber and one type of superabsorbent in each layer, the density of the fiber component in both layers is 1.5 g / cc, the density of the superabsorbent component in both layers is 1.48. g / cc and fractions of superabsorbent mass, liquid charge, and compound heights of each layer are as s specified above. The general porosity values are as follows: Layer 1 region: e = 1 - 240 • 10'4 (0.5 / 1.5 + 0.5 + / 1.48 + 31.05 = 0.29 0.55 Layer 2 region: € "1 450 10" 4 (0.67 / 1.5 + 0.33 + / 1.48 + 15.2 • 0.33 = 0.5 0.51 The values for the permeability of the two layers after carrying out the self-consistent calculation are: Layer 1 region: Layer 2 region K = l.l »10-6cm2 This case of two simple layers serves to illustrate the calculation of permeability composed of principle. However, the compounds used in building the absorbent core of this invention can include more than two components. In such cases, it is necessary to include a permeability equation for each component within a given composite layer region when running the self-consistent composite permeability computation for that layer region. For example, if a composite layer region contains two types of fibers and two superabsorbents, four permeability equations will be required in the Computation of composite permeability when the self-consistent method is used.

With the composite permeabilities and thickness (height, h) determined for each absorbent core layer region in its partially saturated state, as described above, it is now possible to calculate the Flow Conductance Value for the system. As previously described, Flow Conductance Value = + K2h2 + K3h3 So, for the example of two layers given above: Flow Conductance Value = (1.6 * lo-6 * 0.55) + (l.i * lo-6) 0. 51) = 1.4 * IO ^ 5 cm3 Even though the equations given above the permeability and the flow conductance are illustrated for a two-layer structure whose layers each contain an isotropic swelling particle superabsorbent and a fiber type, the calculation of the flow conductance can be extended to cases including more than two layers, and the calculation of "permeability, K can be easily adapted for more complex materials, according to the description set forth herein.

Potential Value of Liquid Transmission Scope This test was used to determine the ability of an absorbent material to remove the liquid from the target area.

Synthesis Determines the amount of liquid to be applied to a sample based on the liquid division calculations. Allow the sample to absorb the liquid from a reservoir and determine the amount of fluid that has been removed from the target area.

Ecruipo and materials A piece of 21 cm by 21 cm of Plexiglass, of similar material, 5 millimeters or less in thickness.

A tank of adequate liquid.

A laboratory balance.

A sample holder to hold the vertical absorbent sample during the addition of the liquid to the sample Binder fasteners for holding the sample in the Plexiglass, such as a binder fastener No. 10050 from IDL Corporation of Caristadt, New Jersey.

Laboratory oven at 150 degrees Celsius.

Test Materials The test liquid, the salt water solution; recommended salt water, blood bank saltwater solution, such as Catálog No. 8504 blood bank saltwater obtained from Stephens Scientific, a division of Cornwell Corporation, a business having localized offices in Riverdale, New Jersey; or an essential equivalent.

Sample Preparation Remove the sample layer region of the product, or otherwise prepare a sample having the same shape as it will exist in the product. Each layer must be separated and tested separately.

Mark the target location with a permanent ink marker. The target location of the layer being tested was determined when the layer is in its proposed position in the absorbent core. The target location is in a laterally centered area which is located inward of the terminal front edge of the absorbent layer extending forward furthest from the absorbent core by a distance equal to 36% of the overall length of the absorbent matrix. Therefore, the absorber layer extending further forward further away from the absorbent core is not necessarily the layer being tested.

Mark the target area on the sample with a permanent ink marker. The target area of the sample layer being tested was determined when the layer is in its proposed position in the absorbent core. The target area of the test sample layer is the area of the sample layer which lies between two lines that extend laterally. The first line is positioned inward of the terminal front edge of the absorbent layer extending further forward further away from the absorbent core by a distance equal to 24% of the overall length of the absorbent core. The second line is placed inward of the terminal front edge of the absorbent layer that extends farther forward farther away from the absorbent core by a distance equal to 59% of the overall length of the core absorbent. Both lines are essentially perpendicular to the central line extending longitudinally of the absorbent core. If both of these two objective area lines fall outside the boundary edges of the absorbent sample that is being tested, then the Liquid Transmission Value of the sample being tested will be zero or defined.

Calculate the amount of liquid that will be absorbed by the sample by using the liquid division calculations, as stated in the description to calculate the Flow Conductance Value. However, rather than calculating the superabsorbent polymer saturation for each layer, determine only the amount of the predicted liquid to be within each layer. This can be done by using the following equation: Liquid in Layer "j" = (j Pj) * 1.0 * Surface Area of Objective Area (for example, for the example given with the description of the determination of the Flow Conductance Value, 61.6 grams of the liquid in the layer 1 region and 38.4 grams of liquid in the layer 2 region, when a surface area is employed of target area of 100 cm2).

Installation procedure Place the sample on the Plexiglass sample holder so that the location of the lens is directly on the bottom of the device.

Fill the liquid reservoir to a point approximately 1 cm from the top.

Place the reservoir on the laboratory scale.

Test Procedure Subtract the tare from the balance, Suspend the sample in the tank so that the liquid touches the absorbent system. The fluid contact must be maintained through the procedure.

Use the laboratory balance as a reference; allow the absorbent compound to absorb the amount of fluid determined in the previous calculations. Remove the deposit sample when the sample has absorbed an amount equal to that based on the fluid division calculations ± 5 grams.

Allow the sample to remain undisturbed for 5 minutes in the vertical position.

Cut the sample into the target area marks and remove the center part. Weigh the remaining sections.

Dry the remaining sections in an oven overnight.

Weigh the dry samples and subtract this weight from the wet weight to determine the amount of liquid which moved out of the target area. Divide the amount of liquid removed from the target area (the amount measured by the previous step) by the total amount of liquid applied to that of the layer in the transmission test; and multiply that result by 100. This is the Potential Transmission value of the layer region.

Transmission Value-Combined Conductance (C) The Combined Transmission-Conductance Value can be determined according to the following formula: (LWV) C = (FCV) + (3 »106) where: FCV = Flow Conductance Value in units of cm3.

L V = Liquid Transmission Value in percent; Y (3 «106 has the units of cm" 3.

Modified Absorbency Under Load (MAUL) Scope This test is designed to measure the ability of a particulate superabsorbent polymer (SAP) to absorb salt water while it is under a constant load of 0.3 psi (2.07 KPa). More specifically, the test measures the amount of salt water absorbed by 0.160 grams of superabsorbent polymer, which has been pre-screened through a standard US # 30 mesh and retained on a # 50 standard mesh. The United States of America, when it is confined within an area of 5.07 cm2 under a pressure of 0.3 psi (2.07 KPa). A suitable test device is shown representatively in Figures 10 to 14.

Equipment and Materials Electronic balance, accuracy at 0.001 grams (20 grams minimum capacity).

Cylinder group: plastic cylinder of inch (25.4 mm) inner diameter (120) with a grid of 100 mesh steel mesh fixed to the bottom of the cylinder; plastic piston disk 4.4 grams (122) with a diameter of 0.99 inches (25.27 mm). The diameter of the piston disk is 0.00 inches (0.13 mm) smaller than the inside diameter of the cylinder. See figure 11. 100 grams of weight (124) having a diameter of 0.984 inches (25 mm). 0. 9% (weight / weight) NaCl solution (Salt Water d Blood bank) Basin for salt water (126) Stopwatch (140) able to read 200 minutes at intervals of one second.

Heavy paper The Standard Test Sieve grouping of the United States of America (Description A.S.T.M. E-ll) including a receiver, a # 30 standard US mesh, and a # 50 standard US mesh, and a cap. A touch device is placed on top of the sample to provide a consistent touch on the support piston disk as illustrated in Figures 10 and 12. This light blow dislodges any trapped air surrounding the superabsorbent polymer and ensures that the liquid moistens the surface of the superabsorbent polymer. In this positioning, a motor (128) rotates an axis which drives a rod (130) along a stroke up and down. At the lower end of the rod is a rubber foot (132) which has a diameter of 13 mm, as illustrated in figure 12. The shaft stroke is 3 cm and completes a cycle of upward stroke and towards down full every 0.7 seconds. The maximum pressure that the piston disk will apply to the superabsorbent polymer at impact is 0.16 psi (0.11 KPa). With reference to Figure 10, an accessory (134) has a vacuum port (136) that allows the interstitial liquid to be evacuated from the sample. The port accommodates the base of the cylinder group. When the cylinder group containing the sample is placed on the accessory, the free liquid is removed from the sample particles. A suitable pump (138) applies a vacuum pressure applied to the sample at 100 torr (13.3 KPa) or less.

Figure 10 shows the complete test placement. It should be noted that electronic chronometers (140) are desirably employed to control the duration of touch and vacuum devices. In this placement, the touch device also rests on a platen (142) which will allow movement between the multiple samples.

Process 1. Using the United States standard test sieve cluster, screen enough superabsorbent to provide a minimum of 0.160 grams that passes through the # 30 mesh grid and is retained on the # 50 mesh grid. 2. Weigh 0.160 grams (± 001 grams) of superabsorbent sifted from step 1 onto the weighing paper that has previously been removed from the tare. 3. Slowly pour the superabsorbent into the cylinder having the 100 mesh bottom. Avoid allowing the superabsorbent polymer to make contact with the sides of the cylinder because the granules can adhere. Tap the cylinder lightly until the granules are distributed evenly on the grid. 4. Place the plastic piston in the cylinder. Weigh the cylinder group and record the weight as the "amount of cylinder group superabsorbent". 5. Fill the saltwater basin to a height of 1 cm with the salt water from the blood bank. 6. Place the cylinder group in the salt water basin, directly below the axis of the toquing device and start the timing. Start the touch device to play for a period of eight seconds. 7. Within five seconds of the end of the eight second touch period, place 100 grams of weight on top of the cylinder group piston, as illustrated in Figure 11. 8. 200 minutes after the cylinder was placed on the basin, remove the cylinder group and the weight, place the cylinder group and 100 g of weight on the vacuum platform, as illustrated in figure 13. Apply the vacuum by a period of 6 seconds. 9. Remove the weight of 100 grams from the cylinder group, weigh the cylinder group and record the weight.

Results v Analysis For each test, calculate the grams of salt water absorbed per gram of superabsorbent polymer. This is the modified absorbency value under load for the superabsorbent.

Absorbency Flooded Under Zero Load (FAUZL) Scope This test is designed to measure the salt water absorption rate of the particulate superabsorbent polymer (SAP). The test measures, as a function of time, the amount of salt water absorbed by 0.160 grams of the superabsorbent polymer (starting either dry or presaturated) when confined within an area of 5.07 cm2 under a nominal pressure of 0.01 psi (0.069). KPa). From the resulting absorption data against time, the characteristic time (Tau) to reach 60% of the equilibrium absorption capacity was determined.

Equipment and Materials Electronic balance, accuracy at 0.001 grams (200 grams minimum capacity).

Cylinder group: 1-inch (25.4 mm) inner diameter (120) plastic cylinder with a 100-mesh steel mesh grid fixed to the bottom of the cylinder; plastic piston disk of 4.4 grams (122) with a diameter of 0.995 inches (25.27 mm). The diameter of the piston disk is 0.005 inches (0.13 mm) smaller than the inside diameter of the cylinder. See figure 11. 0. 9% (weight / weight) NaCl solution (Salt Water from Blood Bank).

Saltwater basin, Stopwatch (140) able to read 120 minutes at one second intervals.

Heavy paper A touch device is placed on top of the sample to provide a consistent touch on the support piston disk as illustrated in Figures 10 and 12. This touch dislodges any trapped air surrounding the superabsorbent polymer and ensures that the liquid moistens the surface of superabsorbent polymer. In this positioning, a motor (128) is rotated to an axis which drives a rod (130) along a stroke up and down. At the lower end of the rod is a rubber foot (132) which has a diameter of 13 mm, as illustrated in figure 12. The shaft stroke is 3 cm and completes this one complete cycle of up and down every 0.7 seconds . The maximum pressure that the piston disk will apply to the superabsorbent polymer upon impact is 0.16 psi (0.11 KPa).

With reference to Figure 10, a device (134) has a vacuum port (136) which allows the evacuation of the interstitial liquid from the sample. The port accommodates the base of the cylinder group. When the cylinder group containing the sample is placed on the fixture, the free liquid is removed from the sample particles. A suitable pump (138) applies a vacuum pressure applied to the sample of 100 torr (13.3 KPa) or less.

Figure 10 shows the complete test placement. It should be noted that electronic chronometers (140) are desirably employed to control the duration of touch and vacuum devices. In this placement, the touch device also rests on a platen (142) which allows movement between the multiple samples.

Process 1. Weigh 0.160 grams (± 0.001 grams) of a superabsorbent over the heavy paper that has previously been subtracted from the tare. The particle size distribution is the particle size distribution "as received". 2. Slowly pour the superabsorbent into the cylinder having a 100 mesh bottom. Avoid allowing the superabsorbent polymer to make contact with the sides of the cylinder because the granules can adhere. Gently touch the cylinder until the granules are distributed evenly over the grid. 3. Place the plastic piston in the cylinder. Weigh this cylinder group and record the weight as the "amount of cylinder group superabsorbent". 4. Fill the saltwater basin to a height of 1 cm with the salt water from blood bank. 5. Place the cylinder group in the saltwater basin, directly below the touch device shaft and start the stopwatch. Start and operate the device 6. Five minutes after the cylinder was placed in the basin, remove the cylinder, stop the chronometer and place the cylinder on the vacuum platform, as illustrated in figure 14. Apply the vacuum for a period of 6 seconds. 7. Weigh the cylinder group and record the weight. 8. Return the cylinder group to the basin below the touch device and start the timing again. Note that the time between the removal of the saltwater cylinder group in step 6 to reintroduce the cylinder group to the salt water in step 8 should not exceed 30 seconds. Repeat the initial sequence of soaking, removal, vacuum placement and weighing to collect and collect the data in cumulative soaking times of 1, 5, 10, 15, 30, 45, 60, 75, 90 and 120 minutes. 9. Conduct the procedure described in steps 1-8, a total of three times.

Results v Analysis Calculate the grams of salt water absorbed per gram of superabsorbent polymer and draw as a function of cumulative soaking time.

Determine the ultimate equilibrium absorption capacity of the superabsorbent polymer: If there is less than a 5% change in the average capacity (average of three tests) of the superabsorbent polymer obtained at 90 and 120 minutes, the use of capacity at 120 minutes as the equilibrium capacity, absorbed flooded under zero load. If there is more than 5% change in average capacity, then the sample test will require repeating and you will need to include additional sampling at a cumulative 200 minute soak time. Use the capacity at 200 minutes, the equilibrium capacity of absorbed flooded under zero load, for this last situation.

Determine the interpolated time (Tau) to reach 60% of the equilibrium absorption capacity. This is done by calculating the capacity at 60% of the equilibrium value, then estimating the corresponding time to reach its capacity from the graph. The interpolated time to reach 60% capacity (by this procedure) was obtained by carrying out a linear interpolation with the data points that lie on each side of the estimated time.

Calculate the interpolated time of arithmetic average to reach 60% of the equilibrium capacity (average of three tests). This average time value is referred to as "Tau" (T).

Contact Angle of the Liquid with the Fibers A suitable technique for measuring the contact angle of the liquid with a fiber is described in U.S. Patent No. 5,364,382, the complete disclosure of which is incorporated herein by reference in a manner that is consistent with the same In particular, the wettability of the fibers can be determined using contact angle measurements on the fibers. Repeated cycling single fiber contact angle measurements using distilled water can be carried out with a Cahn Surface Force Analyzer (SFA222) and an ET-TEK data analysis program. SFA222 is available from Cahn Instruments, Inc., of Cerritos, California, and the ET-TEK program is available from Biomaterials International, Inc., of Salt Lake City, Utah. The fibers are tested through three measurement cycles, and the distilled water bath is changed between cycles 1 and 2. The contact angle of the liquid for the fiber material is determined by taking the arithmetic average of the three measurements . The test instrument is operated in accordance with the standard operating techniques described in the SFA-222 Cahn System Instruction Manual supplied by the manufacturer.

Examples The following examples are presented to provide a more detailed understanding of the invention, and are not intended to limit the scope of the invention. In the various examples, it should be noted that the first primary layer part 48 can alternatively be referred to as the upper layer or the higher layer, and the second primary layer part 50 can alternatively be referred to as the bottom layer or the bottom layer .

Example 1 The side-to-body layer is a basis weight of 500 grams per square meter and is composed of 50% superabsorbent 53C, a superabsorbent available from Dow Chemical, and 50% mercerized pulp HPF2, a material available from Buckeye Corporation. The superabsorbent 53C has an r of 8.5 minutes; a flooded absorbency capacity under zero load of 33 g / g; and a Modified Absorbency Under Load value of 0.3 psi of 26.2 g / g. The side-to-body layer extends over the area of the layer region 48 shown in Figure 2, and is densified at 0.2 g / cc.

The outer side layer is composed of three layers of 68 gsm of tissue dried through non-creped air, composed of 50% HPZ fibers available from Buckeye Celullose Corporation, and 50% LL19 fibers available from Kimberly-Clark Company, extending over the entire pad area (the area of layer 50). A 50 gsm layer of SXM 880 superabsorbent, available from Stockhausen, was placed between the outermost layer of tissue and the adjacent tissue, using 10 gsm of adhesive. The SXM 880 superabsorbent has a T of 4 minutes; a capacity of absorbency sunk under zero load of 38 g / g; and 0.3 psi of Modified Absorbency Value Under Load of 29.8 g / g. Two additional sheets of tissue dried through non-creped air as previously described were placed in the areas outside the area occupied by the side-to-body layer 48. Between these two layers is a 100 gsm layer of superabsorbent SXM 880, bonded using 10 gsm of the aforementioned adhesive.

This example has a Flow Conductivity Value of 3.56 x 10"6 cm3 and a Liquid Transmission Value of 56.2% Example 2 The side-to-body layer is of a basis weight of 500 grams per square meter and is composed of 50% superabsorbent 53C, a superabsorbent available from Dow Chemical, and 50% HPF2 mercerized pulp available from Buckeye Corporation. The superabsorbent DOW 53C has an r of 8.5 minutes; an absorbance capacity sunk under zero load of 33 g / g; and a 0.3 psi Modified Absorbency Value Under Load of 26.2 g / g. The side-to-body layer extends over the area of the layer region 48, as shown in Figure 2, and is densified at 0.2 g / cc.

The outer side layer is comprised of four 68-gsm layers of tissue dried through non-creped air composed of 50% HPZ fiber from Buckeye Celullose and 50% LL19 fiber available from Kimberly-Clark Company. The SXM 880 superabsorbent available from Stockhausen is distributed so that it has a basis weight of 50 gsm in the area under the side-to-body layer and a basis weight of 150 gsm in the areas outside it. The supersorbent extends over the entire area of the pad (the area of layer 50). The superabsorbent is SXM 880 has a r of 4 minutes; an absorbance capacity sunk under zero load of 38 g / g; and 0.3 psi of Modified Absorbency value under load of 29.8 g / g. The superabsorbent is placed in the form of a sandwich between the second and third outermost layers of the tissue.

This example has a Flow Conductivity Value of 3.56 x 10"6 cm3 and a Liquid Transmission Value of 50.0%.

The data mentioned above can be summarized as follows: Some conventional absorbent structures have identified the need for improved distribution, and other conventional structures have identified the need for improved intakes. conventional structures, however, have not been configured to provide the distinctive combination of liquid intake and distribution provided by the various arrangements and aspects of the present invention. The following Comparative Examples 4 to 8 were prepared.

Example # Top Layer Top Layer Bottom Layer Bottom Layer SAP Type Type Erase SAP Type Erase Type SAP BW BW Erase SAP BW Erase BW Example 4A SXM 880 CR-1654 SXM 880 CR-1654 215 gsm 400 gsm 78 gsm 232 gsm Example 5B 20/30 SXM 870 CCLC 60/100 SXM 870 CCLC 269 gsm 292 gsm 529 gsm 294 gsm Example 6B SXM 870 CCLC 60/100 SXM 870 CCLC 159 gsm 295 gsm 319 gsm 295 gsm ? j emplo 7B 20/30 SXM 870 CCLC 60/100 SXM 870 CCLC 99 gsm 281 gsm 239 gsm 281 gsm Example 8C N / A CCLC SXM 880 CR-1654 300 gsm 250 gsm 250 gsm It is believed that Example 4 is representative of the structure taught by U.S. Pat. No. 5,356,403 to Faulks et al. In Example 4, the upper layer has a density of 0.2 g / cc and the lower layer has a density of 0.3 g / cc.

B It is believed that Examples 5 to 7 are representative of the structures taught by European Patent EP 0 631 768 Al by Plischke et al. In these examples, both layers have a density of 0.2 g / cc and both layers extend over the entire area of the composite pad form described in EP 0 631 768 A1. c It is believed that Example 8 is representative of the structure taught by U.S. Patent No. 5,360,420 to Cook et al. The top layer has a density of 0.07 g / cc, and the bottom layer has a density of 0.25 g / cc. Both layers have the form described in U.S. Patent No. 5,360,420.

CCLC is cellulose chemically cross linked, as described in U.S. Patent No. 4,898,642, for example.

The SXM 870 and SXM 880 are superabsorbents produced by Stockhausen under the FAVOR SX brand. Where indicated, the superabsorbent is screened to the particle size listed on the mesh; for example, 20/30 meshes (600 to 850 μm), 60/100 meshes (150 to 250 μm). The SXM 880 superabsorbent has a T of 4 minutes; a capacity of absorbency sunk under zero load of 38 g / g; and a Modified Absorbency Under Load value of 0.3 psi of 29.8 g / g.

The SXM 870 superabsorbent has a T of 4 minutes; a capacity of absorbency sunk under zero load of 32.5 g / g; and a Modified Absorbency Under Load value of 0.3 pounds per square inch of 27 g / g.

The superabsorbent "20/30 SXM 870" has a t of 6. 4 minutes; a capacity of absorbency sunk under zero load of 34 g / g; and a Modified Absorbency Under Load value of 0.3 psi of 28.8 g / g.

The superabsorbent "60/100 SXM 870" has a T of 3. 3 minutes, a capacity of absorbency sunk under zero load of 27.5 g / g and a value of Modified Absorbency Under Load of 0.3 psi of 25.3 g / g.

Examples 4-8 exhibited the characteristics set forth in the following table.

As can be seen, the structures of these examples do not provide the combination of features provided by the structures of the present invention.

Having described the invention in quite complete detail, it will be readily apparent that various changes and modifications can be made without departing from the spirit of the invention. All such changes and modifications are contemplated as being within the scope of the invention.

Claims

R E I V I N D I C A C I O N S

1. An absorbent article comprising: a lower sheet layer; a top sheet layer essentially permeable to liquid; an absorbent composite structure sandwiched between the bottom sheet and top sheet layers; said absorbent composite includes an absorbent core having a first layer region and at least a second primary layer region; said second primary layer region has a selectively zoned non-uniform basis weight; at least one of said first and second primary layer regions includes a series of sublayers; Y at least one of said first and second primary layer regions having a Liquid Transmission Value of at least about 38%.

2. An article as claimed in clause 1, characterized in that said absorbent core has a dry thickness of no more than about 6 mm, and a minimum crotch width of no more than about 10 cm.

3. An article as claimed in clause 1, characterized in that said article is configured for use by an adult and wherein said absorbent core has a dry thickness of no more than about 6 mm, and a minimum crotch width of no more than about 14 cm.

4. An article as claimed in clause 1, characterized in that said absorbent matrix has a Transmission-Conductance Value of at least about 14 * 10"6 cm3.

5. An article as claimed in clause 4, characterized in that said absorbent core has a dry thickness of no more than about 6 mm, and a minimum crotch width of no more than about 10 cm.

6. An article as claimed in clause 1, characterized in that said first primary layer region is located on one side of the body of the absorbent compound, and said second primary layer region is located relatively away from the first layer region.

7. An absorbent article as claimed in clause 1, characterized in that at least one of said primary layer regions includes a superabsorbent material having a value of Modified Absorbency Under Average Load of at least about 20 g / g.

8. An absorbent article as claimed in clause 1, characterized in that at least one of said primary layer regions includes a superabsorbent material which exhibits a Tau value of not less than about 0.8 minutes.

9. An absorbent article which includes an absorbent core having a first primary layer region and at least a second primary layer region; where: said second primary layer region has a selectively zoned non-uniform basis weight; said second primary layer region includes a heterogeneous plurality of subpasses; said absorbent matrix has a longitudinal extension, a lateral width and a designated front edge; said first primary layer region has a basis weight of not less than about 100 g / m2 and no more than about 700 g / m2; said first primary layer region has a first layer region density of not less than about 0.03 g / cm3 and no more than about 0.4 g / cm3; said first primary layer region includes a fibrous material in an amount which is not less than about 25% by weight and is not more than about 80% by weight; said fibrous material includes fibers having fiber sizes which are not less than about 4 μm and not more than about 20 μm; said primary layer region includes a superabsorbent material in an amount which is not less than about 50% by weight and is not more than about 80% by weight; said superabsorbent material includes superabsorbent particles having particle sizes which are not less than about 110 μm and are not more than about 1000 μm; said superabsorbent material has a Modified Absorbency Under Load value of not less than about 20 g / g; Y said superabsorbent material has a Tau value of not less than about 0.8 minutes.

10. An article as claimed in clause 9, characterized in that said first primary layer region is essentially cotermin with the lateral edges of said second primary layer region; Y said first primary layer region contained within a zone which begins in a laterally extending line placed about 7% of the core length inward of the most frontal edge of the absorbent core and extends to a laterally extending line placed at about 62% of the core length inward of the most frontal edge of the absorbent core.

11. An article as claimed in clause 10, characterized in that said first primary layer region includes a binder material.

12. An article as claimed in clause 9, characterized in that said second primary layer region includes a plurality of sublayers having a material dried through non-creped air.

13. An article as claimed in clause 9, characterized in that said second primary layer region has a longitudinal extension which is greater than a longitudinal extension of said first primary layer region; and said second primary layer region has a lateral extension which is essentially coterminous with the first primary layer region.

14. An article as claimed in clause 9, characterized in that said second primary layer region has a longitudinal extension which is greater than a longitudinal extension of said first primary layer region; said second primary layer region has a lateral extension which is smaller than a lateral extension of said first primary layer region; Y A lateral extension of at least a portion of said second primary layer region is not less than about 30% of the lateral extent of a correspondingly adjacent portion of said first primary layer region.

15. An article as claimed in clause 9, characterized in that said second region of primary cap has a longitudinal extension which is greater than a longitudinal extension of said first primary layer region; said second primary layer region has a lateral extension which is greater than a lateral extension of said first primary layer region; a lateral extension of at least a portion of said first primary layer region is not less than about 30% of the lateral extent of a correspondingly adjacent part of said second primary layer region.

16. An article as claimed in clause 9, characterized in that a target area of said second primary layer region has a basis weight which is lower than a basis weight of the non-target portions of said second layer region. primary.

17. An article as claimed in clause 9, characterized in that said target area of said second primary layer region has a basis weight which is not less than 100 g / m2 and is not more than about 250 g / m2; Y a non-target portion of said second primary layer region has a basis weight which is not less than 450 g / m2 and is not more than 550 g / m2.

18. An article as claimed in clause 17, characterized in that said second primary layer region has a second layer region density of not less than about 0.1 g / cm3 and not more than about 0.3 g / cm3; said second primary layer region includes a fibrous matrix in an amount which is not less than about 50% by weight and is no more than about 95% by weight; said fibrous material includes fibers having fiber diameters which are not less than about 4 μm and not more than about 20 μm; said fibrous material includes fibers which exhibit a contact angle with water of no more than about 70 degrees; said second primary layer region includes a superabsorbent material in an amount which is not less than about 5% by weight and is not more than about 50% by weight; Y said superabsorbent material includes superabsorbent particles having dry particle sizes which are not less than about 110 μm, and are not more than about 1000 μm.

19. An article as claimed in clause 18, characterized in that said superabsorbent material in said second primary layer region has an absorbance value under mean load of not less than about 20 g / g and has a Tau value of at least of about 0.4 minutes.

20. An article as claimed in clause 19, characterized in that said superabsorbent material in said second primary layer region is formed as a superabsorbent layer laminated between the layers of material dried through non-creped air.

21. An article as claimed in clause 20, characterized in that said article further comprises a lower sheet layer and an upper sheet layer essentially permeable to liquid, which are configured with said absorbent matrix placed in the form of a sandwich between them. .

22. An article as claimed in clause 21, characterized in that said absorbent core has a Flow Conductance Value of at least about 7 * 10"6 cm3; at least one of said first and second primary layer regions has a Liquid Transmission Value of at least about 16%.

23. An article as claimed in clause 22, characterized in that at least one of said first and second primary layer regions has a Liquid Transmission Value of at least about 36%. SUMMARY A distinctive absorbent article includes an absorbent core having multiple absorbent layers, wherein the absorbent layers interact in a manner such that they preferably locate the liquid absorbed in a layer designated as high saturation transmission. The location of the liquid within the transmission layer increases the potential of this layer to move the liquid through the capillary action due to the higher saturation level in the incremental amount of the available liquid. The intake capacity of the absorbent system is maintained or improved on current systems by maintaining a second layer of the absorbent system at low saturation levels through as many product discharges as possible, while providing optimum performance. through proper control of composite properties. The low saturation in this layer provides a hollow volume for the incoming discharge as well, such as a high permeability, thus increasing the absorption rate of the absorbent system as a whole, but the structure of the low saturation layer is also balanced to provide u suitably high level of capillary tension to provide sufficient control of the liquid to prevent the occurrence of runoff.This low saturation layer is used in addition to an emergence material and provides a functionality d toma in addition to that provided by the material d emergence. In particular aspects of the invention, the side-to-body cap the absorbent core does not extend over the entire surface of the complete absorbent core, hence n is used as the high saturation transmission layer, but as the take-up layer. This arrangement also allows the cap to be in direct contact with the incoming liquid, thereby allowing more immediate access and an improved take-up function. In additional aspects at least one primary layer region may have a base weight distribution. selectively zoned not uniform. The particular configurations of at least one primary layer region may be constructed with a target area of such a primary layer region having a basis weight which is less than a basis weight of another non-target part of the primary layer region. . further, at least one primary layer region may have a heterogeneous structure In particular constructions, the at least one primary layer region may include a plurality of two or more sublayers