MXPA95000034A - Sanitary towel that has an inte configurator component - Google Patents

Abstract

The present invention relates to a sanitary napkin that includes a topsheet, a backsheet, an absorbent core, and a filament spring positioned in the middle of the core and the backsheet. The spring provides an elastic displacement of the upper sheet relative to the back sheet and convexly forms a surface facing the body of the upper sheet.

Description

SANITARY TOWEL THAT HAS A COMPONENT PATERNAL CONFIGURATOR INVENTOR: CARL LOUIS BERGMAN, a citizen of the United States, residing at 6674 Quailrun Court, Loveland, Ohio 45140, United States.

CAUSAHIENT: THE PROCTER & GAMBLE COMPANY, a partnership of the United States, residing in One Procter & Gamble Plaza, Cincinnati, Ohio 45202, United States.

SUMMARY OF THE INVENTION A sanitary napkin that includes an upper sheet, a backing sheet, an absorbent core, and a spring and filament placed in the middle of the core and the backing sheet. The spring provides an elastic displacement of the upper sheet relative to the back sheet and convexly forms a surface facing the body of the upper sheet.

FIELD OF THE INVENTION The present invention relates generally to disposable absorbent articles such as sanitary napkins and, more particularly to a sanitary napkin having an internal spring to displace and configure, a portion of the sanitary napkin.

BACKGROUND OF THE INVENTION Absorbent items such as sanitary napkins, panties, and incontinence pads are designed to absorb and retain fluid and other discharges from the human body. It is generally desirable to provide absorbent articles such as sanitary napkins that remain in contact with the wearer's body when in use, and which conform as much as possible to the wearer's body. It is believed that this ability to conform to the body increases the effectiveness of the sanitary napkin by reducing the possibility that the menses travel around the perimeter of the sanitary napkin and stain the wearer's body and / or clothes. There have been a number of recent efforts to provide sanitary napkins and other absorbent articles with improved fit characteristics. These recent efforts are described in U.S. Patent No. 4,950,264 issued August 21, 1990 to Osborn; Patent of the States of North America Number 5,007,906 issued on April 16, 1991 to Osborn; Patent of the States of North America Number 5,197,959 issued March 30, 1993 to Buell; and U.S. Patent Application Serial Number 07 / 605,583 entitled "Sanitary Napkin Having Components Capable of Separation In Use" filed October 20, 1990. Although the sanitary napkins described in these references represent advances in the art. , the search has continued in new and different ways to improve body contact. It is especially desirable that the sanitary napkin maintain contact with and conform to the user's body under dynamic conditions (when the user walks, sits, etc.). For example, when the sanitary napkin is put on, the sanitary napkin is subjected to a lateral compression of the upper thigh portions of the wearer. The forces applied by the thighs of the wearer generally tend to distort the shape of the sanitary napkin, reducing the size of the objective provided by the sanitary napkin. In the United Kingdom Patent Application 2,168,612A, published on June 25, 1986 an attempt is made to control the effect of these compression forces. The UK patent application describes a sanitary napkin with a resilient insert positioned within the core or adjacent to a face of the core which is intended to inhibit permanent distortion of the towel. The UK application teaches that the insert resists lateral deformation of the sanitary napkin, but does not teach or describe a sanitary napkin having body shaping properties. It is also desirable to provide a sanitary napkin which conforms to the wearer's body while maintaining the comfort of the wearer. Accordingly, a desirable sanitary towel should maintain contact with the user's body, and yet be able to have repeated elastic twisting to allow the user to assume various positions comfortably and perform different activities. Sanitary napkins generally conform to the wearer's underwear by means of adhesives or other means. The movement of the wearer's underwear in relation to the wearer's body may result in a change of the sanitary napkin of the desired position. Therefore, it is also desirable to provide a sanitary napkin that conforms to the body with a mechanism to accommodate independent movement between the wearer's body and the wearer's underwear. It is therefore an object of the present invention to provide an absorbent article, such as a sanitary napkin, which intercepts the menses by conforming to the shape of the female urogenital region. It is another object of the present invention to provide a sanitary napkin having a convexly shaped body facing surface. It is still another object of the present invention to provide a sanitary napkin having a spring for the repeated elastic displacement of an absorbent core and a liquid-permeable upper sheet, relative to a liquid-impermeable backsheet, secured to the underwear of the user. A further objective of the present invention is to provide a sanitary napkin having a nonabsorbent inner spring positioned in the middle of an absorbent core and a backsheet. These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION The present invention is an absorbent article, such as a sanitary napkin. The sanitary napkin of the present invention has a liquid-permeable upper sheet having a body-facing surface, a liquid-impermeable backing sheet bonded to the upper sheet, an absorbent core placed in the middle of the upper sheet and the sheet of backing, and at least one non-absorbent spring placed in the middle of the absorbent core and the backing sheet. The spring provides an elastic displacement with Z direction of a portion of the surface facing the body of the upper sheet, along the longitudinal centerline of the sanitary napkin. The top sheet can be attached to the backing sheet, to provide independent movement of the top sheet and the absorbent core relative to the backing sheet. In one embodiment, the sanitary napkin has at least one longitudinally extending fold, attaching the upper sheet to the backing sheet, to control the separation of the upper sheet from the backing sheet. The spring may include a filament spring attached to the absorbent core in a first position that coincides with the longitudinal centerline of the disposable absorbent article, and attached to the backsheet in laterally spaced positions, positioned symmetrically with respect to the longitudinal center line. The filament spring may have first and second legs arranged in an inverted V configuration, as seen along the longitudinal centerline of the sanitary napkin. In one embodiment, the filament spring may include a plurality of closed turns arranged symmetrically with respect to the longitudinal centerline of the absorbent article. The filament spring provides a sanitary napkin having a first gauge with a Z-direction to a Z-direction compressive load of approximately 2 grams, and a second gauge with a Z-direction, at least 15 mm less than the first gauge with Z direction to a Z-direction compression load of less than 100 grams. By the same, the filament spring can promote compliance with the body and comfort for the wearer by keeping the topsheet in contact with the wearer's body, while providing a relatively low compressive strength of the towel sanitary in the Z-direction. The spring also provides a sanitary napkin having a lateral gauge of less than 10 millimeters at a lateral compression load of 100 grams. By the same, the filament spring allows the top sheet and the core to be compressed laterally at relatively low lateral load levels, to promote both user comfort, and for the top sheet and the core to conform to the User's body in the areas of the lips, perianal, and / or gluteal groove.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top plan view of the sanitary napkin of the present invention, showing portions of the sanitary napkin cut out. Figure 2 is a sectional view taken along line 2-2 of Figure 1, which shows the sanitary napkin of the present invention in a compressed configuration. Figure 3 is a sectional view of the sanitary napkin of Figure 2, showing the sanitary napkin in an extended configuration. Figure 4 is a partial perspective view of the sanitary napkin of the present invention in an extended configuration, with portions of the topsheet, the absorbent core and the backsheet cut to show a filament spring including two closed turns placed in the middle of the absorbent core and the backing sheet. Figure 5 is a partial perspective view similar to that of Figure 4, showing a filament spring including closed turns that overlap in a scissor-like configuration. Figure 6 is a top plan view of a relatively long sanitary napkin of the present invention, which has a plurality of springs placed along the longitudinal axis of the sanitary napkin. Figure 7 is a top plan view of a relatively long sanitary napkin of the present invention, having springs with different configurations, positioned along the longitudinal centerline of the sanitary napkin. Figure 8 is a schematic illustration of a cross section of a sanitary napkin of the present invention, placed between two plates, and showing the method for measuring the lateral gauge of the sanitary napkin under a lateral compression load. Figure 9 is a sectional view of a sanitary napkin in an extended configuration, and having a filament spring including two legs spaced apart from one another in the lateral direction. Figure 10 is a graph of the force with direction in. Z against the Z-direction gauge of a sanitary napkin, as shown in Figure 7, and as measured on the spring 100B.

DETAILED DESCRIPTION OF THE INVENTION Figures 1-3 illustrate a sanitary napkin 20, in accordance with one embodiment of the disposable absorbent article of the present invention. As used herein, the term "absorbent article" refers to articles that absorb and contain body exudates. More specifically, the term is intended to include, but not be limited to, sanitary napkins, panties, and incontinence pads (items used in the crotch region of an article of clothing). The term "disposable" refers to items that are intended to be disposed of after a single use, rather than to wash them or to restore or reuse them in another way. The sanitary napkin 20 includes a liquid permeable upper sheet 22 having a body facing surface 23, a liquid impermeable backing sheet 24 having a garment facing surface 25, an absorbent core 26 in the middle of the upper sheet 22 and the backing sheet 24, and a spring 100 placed in the middle of the absorbent core 26 and the backing sheet 24. The sanitary napkin 20 has two longitudinal ends 28 and two side ends 30. The sanitary napkin also has a longitudinal centerline 29 and a lateral centerline 31. As used herein, the term "longitudinal" refers to a line, axis, or direction generally perpendicular to the longitudinal direction and resting in a plane generally parallel to the plane of the backing sheet 24, when the sanitary napkin is held in a generally flat configuration, as shown in Figures 1 and 2. The sanitary napkin 20 is typically more long in the longitudinal direction than in the lateral direction. The "Z" direction refers to a line, axis, or direction that is perpendicular to the plane of the backing sheet 24, when the sanitary napkin is held in a generally flat configuration, as shown in Figures 1 and 2 ( that is, perpendicular to both the longitudinal axis 29 and the lateral axis 31, when the sanitary napkin is held in a generally flat configuration). The Z-direction is illustrated in Figure 3. The spring 100 provides the Z-directional elastic shift of a portion of the topsheet 22, along the longitudinal centerline 29, and preferably a portion of the absorbent core. 26, relative to the backing sheet 24. Preferably, the spring 100 also convexly forms a portion of the surface facing the body 23 of the topsheet 22, along the longitudinal centerline 29, as shown in Figure 3. By the same, the spring 100 maintains the contact of the upper sheet 22 with the wearer's body, and forms the upper sheet 22 so that it conforms to the wearer's body, particularly in the areas of the lips, perianal, or the gluteal groove. The spring 100 is positioned in the middle of the backsheet 24 and the absorbent core 26, and preferably elastically displaces and shapes both the topsheet 22 and the core 26. At least a portion of the core 26 is biased by the same , in contact with the topsheet 22, to receive the body exudates passing through the liquid-permeable topsheet 22. The spring 100 preferably extends between the core 26 and the backsheet 24, and preferably lifts the core 26 of the backing sheet 24 to provide a hollow space 130. The hollow space 130 extends in the Z direction from the back sheet 24 to the absorbent core 26. It is desirable that the hollow space 130 ensure that the spring 100 is the only element that provides resistance to the movement of the upper sheet 22 and the core 26 towards the backing sheet 24, such as by a compression load 200. Alternatively, the space between e the backing sheet 24 and the absorbent core 26 can be filled partially or completely with a material, such as an absorbent. The "Z-directional elastic shift" of the topsheet 22 relative to the backsheet 24 means that the topsheet 22 can be displaced relative to the backsheet 25 in the Z direction from a first extended configuration with no load having a caliber Z2 shown in Figure 2 (such as the compressive load in the Z direction shown in Figure 2), and that the spring 100 will restore the sanitary pad 20 so that it has a caliber in the Z direction that is at least approximately 70 percent of the Zl caliber of the Z direction when the compressive load is removed when the sanitary napkin is dry and has not been loaded with body exudates. The elastic displacement of the upper sheet 22 can be expressed in relation to the backing sheet 24 by the difference Z1-Z2. The procedure for measuring dimensions Z2 and Zl is described below. Figures 4 and 5 show the sanitary napkin in the relatively unloaded and extended position, with portions of the topsheet 22, core 26, and backsheet trimmed to show the spring 100. The topsheet 22 and the backsheet 24 they join together, joining the longitudinal ends 28 and along one or both of the lateral ends 30. As used herein, the term "joining" refers to the condition in which the first member or component adheres or becomes connects to a second member or component either directly, or indirectly, wherein the first member or component is attached, or connected, to an intermediate member or component which in turn adheres, or connects to, the second member or component. Examining the components of the sanitary napkin 20 in more detail, the topsheet 22 is the component of the sanitary napkin 20 which is oriented towards and connecting the wearer's body to receive exudates from the body. The topsheet 22 is permeable to liquid and must be flexible and non-irritating to the skin. As used herein, the term flexible refers to materials that are flexible and easily conform to the shape of the body or respond by easy deformation in the presence of external forces. Preferably, the top sheet 22 is not noisy to provide discretion to the user. The topsheet 22 should be clean in appearance and somewhat opaque to disguise the discharges collected in the core 26. The topsheet 22 should exhibit good transfer and rehumidification characteristics, allowing the bodily discharges to quickly penetrate the topsheet 22 to the core 26 A suitable top sheet 22 can be made from a wide range of materials such as woven and non-woven materials; polymeric materials such as diaphragm aperture shaped thermoplastic films, diaphragm aperture plastic films, and hydroformed thermoplastic films; porous sponges; cross-linked sponges; crosslinked thermoplastic films; and thermoplastic canvases. Suitable woven and non-woven materials may be composed of natural fibers (for example, wood or cotton fibers), synthetic fibers (for example polymer fibers such as polyester, polypropylene, or polyethylene fibers) or a combination of natural fibers and synthetic. A preferred top sheet 22 includes a diaphragm aperture shaped film. Properly formed films are described in US Pat. No. 3,929,135 issued December 30, 1975 to Thompson; Patent 4,324,246 of the United States of America issued on April 13, 1982 to Mullane et al .; Patent 4,342,314 of the United States of America issued on August 3, 1982 to Radel et al .; Patent 4,463,045 of the United States of America issued on April 9, 1991 to Barid; which patents are incorporated herein by reference. A preferred top sheet 22 includes a film in the form of a diaphragm aperture attached to a nonwoven acquisition foaming sheet, as published in U.S. Patent 4,950,264 issued August 21, 1990 to Osborn, which patent it is incorporated herein by reference. The backsheet 24 can be of any flexible liquid impervious material, such as a polyolefin film. The backing sheet 24 prevents the discharges collected by the sanitary napkin 20 from soiling the wearer or the wearer's clothes. The backing sheet 24 can be a low density polyethylene film of from about 0.01 to about 0.05 millimeters thick. Ethy Corp., Visqueen Division, sells a suitable low density polyethylene film, as Model XP-39385, and by Clopay Corporation of Cincinnati, Ohio under the designation P18-1401. The backsheet 24 may be longer than the topsheet 22 and the absorbent core 26, and preferably circumferentially surrounds the topsheet 22 and the core 26. The backsheet 24 may include wings 44 extending outwardly from each side. longitudinal edge 28. The wings 44 can be made in accordance with the teachings of the Patents of the United States of America numbers 4,589,876 issued May 20, 1986 to Van Tilburg and 4,687,478 issued August 18, 1987 to Van Tilburg, which patents are incorporated by reference. The back sheet 24 and the wings 44 can be unitary and coextensive. Alternatively, the wings 44 may be separate components attached to the backsheet 24. The front surface 25 of the backsheet garment 24 may include attachment means 38 for securing the sanitary napkin 20 to the underwear of the backing sheet. user. Preferred attachment means 38 include mechanical fasteners, or more preferably, pressure sensitive adhesive 38. The pressure sensitive adhesive 38 can be applied to the front surface 25 of the garment in one or more strips or patches. As shown in Figures 1 and 2, the pressure sensitive adhesive 38 can be positioned near the distal end of each wing 44, as well as in a portion of the back sheet 24 that foundations the top sheet 22 and the absorbent core. 26. A suitable adhesive 38 is the Century Adhesive A305-IV, which is supplied by Century Adhesives Corp. of Columbus, Ohio. The absorbent core 26 receives and contains body exudates, particularly menstruation. The absorbent core 26 should be flexible and non-irritating to the skin and can have any number of shapes including a rectangular or hourglass figure. The absorbent core 26 has a first face 40 facing the backing sheet 24, and a second opposing face 42 facing the top sheet 22. Suitable materials for making the core 26 can include but are not limited to the pulp combinations of shredded wood, such as cellulosic filling, and fibrous pulp of communion; layers of toilet paper; and absorbent gelatinous materials. Examples of other suitable materials from which the core can be made include meltblown polymers; chemically hardened, modified or bonded cellulosic fibers; and synthetic fibers. An exemplary core 26 includes a laminated bath paper and absorbent gelatinous material. Such a core is published in U.S. Patent 4,950,264 issued August 21, 1990 to Osborn, and U.S. Patent 5,007,906 issued April 16, 1991 to Osborn et al., Which patents are incorporated by reference for the purpose of teaching a construction suitable for the core 26. Preferably the core 26 and the top sheet 22 are joined to form a laminate such that the core 26 and the top sheet 22 can be moved by the spring 100 as a unit. The second face 42 of the core 26 can be attached to the topsheet 22 by any suitable means, preferably with an adhesive attachment. A suitable adhesive is a hot melt adhesive such as the Findley 2031 Adhesive available from Findley Adhesives of Elmgrove, Wisconsin. Said integration of the topsheet 22 with the absorbent core 26 maintains contact between the topsheet 22 and the core 26 during use, and provides a capillary suction of the fluids passing through the topsheet 22 within the core 26. The sanitary napkin 20 according to the present invention has the core 26 and associated upper sheet 22 detached from the backing sheet 24 such that the upper sheet 22 is attached to the backing sheet 24 to provide independent movement in the Z direction of the upper sheet 22 and the core 26 in relation to the backing sheet 24. The suitable construction of sanitary napkins that provide such a detached movement in the Z direction of the upper sheet 22 and of the core 26 in relation to the backing sheet 24 is published in U.S. Patent 5,007,906 issued April 16, 1991 to Osborn et al., which patent is incorporated herein by reference Eference Such uncoupling is desired to allow the topsheet 24 and the core 26 to be lifted by the spring 100 to contact the wearer's body, while allowing the backsheet 24 to remain attached to the wearer's garment. by the means of adhesion 38. The sanitary napkin 20 may have a means for controlling the amount of directional separation of the topsheet 22 and the associated core 26 of the backsheet 24. A suitable means for providing such control is one or more longitudinally extending folds 52 which form a connection joining the upper sheet 22 to the backing sheet 24. As used herein, a "longitudinally extending fold" is a component of the sanitary napkin 20 having a line of bending 54 extending longitudinally to provide one or more layers of material in the Z direction along bending line 54. Preferably it is proportional to the longitudinally extending pleats 52, one at each longitudinal end 28 of the sanitary napkin 20. The longitudinally extending crease 52 may be an extension of the topsheet 22, an extension of the backsheet 24, or an extension piece of the backsheet 24. separate material having an end attached to the topsheet 22 and an end attached to the backsheet 24. The portion of the topsheet 22 forming each fold is folded under a portion of the topsheet 22 laterally inward of the ends longitudinals 28 and attached to the backing sheet 24 along the link lines 56. The link lines 56 include hot-bond or adhesive bond lines. Preferably the link lines 56 are continuous to form a seal between the topsheet 22 and the backsheet 24, and may include adhesive bond lines between the topsheet 22 and the backsheet 24. The plies 52 have a side width W (Figure 2) as measured from the link line 56 to the fold line 54 at a position laterally attached to the spring 100. The width W can be selected to accommodate a desired amount of displacement in the Z direction of the top sheet 22 relative to the backing sheet 24 provided by the spring 100. The link lines 56 and the lines of fold 54 may be generally parallel, as shown in Figure 1, to accommodate an equal amount of shifts in Z-direction along the length of sanitary napkin 20. Alternatively, link lines 56 or fold lines 54 can diverge or converge along the sanitary napkin 20, as shown in Figure 6, to accommodate different amounts of Z-direction travel of the topsheet 22 and core 26 along the length of the sanitary napkin 20. The pleats 52 shown in Figures 1-3 are extensions of the topsheet 22 and include a single fold line 54 to form a C-shaped fold. Alternatively, they can be used the accordion-shaped folds having a plurality of fold lines 54. U.S. Patent No. 5,007,906 referred to above, is incorporated herein by reference for the purpose of describing suitable constructions for the longitudinally extending folds 52. The upper sheet 22 can be left unattached to the backing sheet 24 at one or both side ends 30 to further accommodate the Z-direction decoupling of the upper sheet 22 from the backing sheet 24. By leaving the top sheet 22 without holding the backing sheet 24 at one of the side ends 30, the decoupling with the direction of n Z of the topsheet 22 and the core 26 of the backsheet 24. Additionally, by leaving the top sheet 22 unclamped to the backsheet at one of the side ends 30, such as at a rear side end 30B ( Figure 6), also accommodates the decoupling of the upper sheet 22 and the core 26 of the backing sheet 24 in the longitudinal direction. This longitudinal decoupling allows a relative movement of the upper sheet 22 and the core 26 with respect to the back sheet 24 (and of the wearer's underwear to which the back sheet is attached) in the plane of the sanitary napkin 20. The backsheet 24 should remain in place over a radius of curvature different from the radius of curvature of the topsheet 22 and the core 26 if the backsheet 24 should remain attached to the wearer's underwear while the upper sheet 22 and core 26 are in close conformity with the wearer's anatomy. The longitudinal uncoupling of the upper sheet 22 and the core 26 of the back sheet 24, in combination with the Z-direction decoupling of the upper sheet 22 and the core 26 from the backing sheet 24, accommodates the dividing forces caused by this difference in the radii of the curvature. Additionally, the longitudinal segmentation of the core 26, as described below, allows different decoupling with Z-direction of the core 26 of the backing sheet along the length of the sanitary napkin. Alternatively, a longitudinal uncoupling can be provided by attaching the upper sheet 22 to the backing sheet 24 at one of the side ends 30, such as the rear side end 30B, by a laterally extending fold (not shown) to accommodate additionally decoupling with Z-direction to provide a longitudinal uncoupling of the topsheet 22 and the core 26 with respect to the backsheet 24 in the plane of the sanitary napkin 20. The combined laminate of the core 26 and the topsheet 22 must be flexible so that the surface facing the body 23 of the upper sheet 22 and the second face 42 of the core 26 can be convexly formed by the spring 100. The laminate of the core 26 and the upper sheet 22 can be formed by same to the body of the user. In a preferred embodiment, core 26 and upper sheet 22 have a combination of Taber stiffness and flexure, as measured in both longitudinal and lateral directions, of less than about 3.0 grams-centimeters, and more preferably less than about 2.0 grams-centimeters. The Taber stiffness and bending of a sample of the laminate of the upper sheet 22 and of the core 26 with dimensions of 3.8 centimeters (1.5 inches) in width and 3.8 centimeters (1.5 inches) in length can be measured in accordance with the TAPPI method T489 -76 using a V-5 Stiffness Tester, Model 150-B, such as the one available with Taber Intru ents from the Teledyne Corp., North Talawanda, New York. The Taber stiffness and bending in the longitudinal direction is calculated by averaging at least 10 readings taken from at least 5 samples. Similarly, Taber's stiffness and bending in the lateral direction is calculated using at least 10 readings taken from at least 5 samples. The stiffness test is conducted with a test range of 0-10, a weight range of zero, and a 10-unit compensating weight. The rigidity tester rolls are mounted above to provide a test duration of 1.0 cm (0.39 inches). Each sample has a vertical subject width and deviates 15 degrees from the center line position by applying a 1.0 centimeter (0.39 inch) flex load of the fasteners as measured in the longitudinal direction for the longitudinal stiffness value, and as measured in the lateral direction for the lateral stiffness value. Each sample is deflected in two opposite directions using the stiffness tester (eg, first right, then left) to provide two readings. The average of the readings is divided by the compensating weight (10) to obtain the Taber stiffness value in grams-centimeters. The laminate of the topsheet 22 and the core 26, or a portion thereof, can be mechanically worked or smoothed, such as by rolling it, to improve its flexibility. In the Patent of the United States of North America Number 4,107,364 issued to Sisson on August 15, 1978; U.S. Patent Number 4,834,741 issued to Sabee on May 30, 1989; U.S. Patent No. 5,143,679 issued September 1, 1992 to Weber et al .; U.S. Patent No. 5,156,793 issued October 20, 1992 to Buell et al; and U.S. Patent No. 5,167,897 issued December 1, 1992 to Weber et al., describes processes suitable for mechanically working or rolling whose patents are incorporated herein by reference. In one embodiment the laminate of the topsheet 22 and the core 26 can include at least a pair of longitudinally extending hinge lines, arranged symmetrically with respect to the longitudinal axis 29. With reference to Figure 6, it is shown that the surface front 23 of the upper sheet body 22 has a pair of hinge biconvex lines 62 (shown with dashed lines in Figure 6) positioned laterally inward of a pair of hinge biconcave 64 lines. The hinge lines 62, 64 may include, but are not limited to, relief or compression lines, bends, lines with notches or pre-bent lines. Said longitudinally extending hinge lines 62, 64 facilitate convex formation of the front surface 23 of the body of the upper sheet 22 when the sanitary napkin 20 is in the extended position shown in Figure 3. The hinge lines 62 they assist the upper sheet 22 and the core 26 to conform to the holes of the lips, perianals and of the gluteal groove, and the hinge lines laterally outwardly 64 assist the upper sheet 22 and the core 26 to be conform to the outline of the user's legs. In one embodiment, the ability of the spring 100 to reset the Z-direction gauge of the sanitary napkin 20 relatively is not affected by the wetting of the spring 100. The spring 100 may have a reduction in moisture gauge that is not more than about 20 percent greater than its dryness gauge reduction, and a moisture gauge reduction of no more than about eight percent. The reduction of the moisture gauge and the reduction of the dryness gauge for the spring 10 are measured using the following repeated procedure for four spring samples. The spring 100 is adhered to a sheet of polyethylene film having a thickness of approximately 1.0 millimeters. The spring 100 and the polyethylene film are supported on the horizontal surface of an analytical balance, or of another suitable scale. The Z-direction gauge of the spring 100 on the polyethylene film is measured using a suitable displacement measurement system. A suitable displacement measurement system is a ONO-SOKKI DG 3610 Digital Indicator and a Linear Sensor Indicator available from the ONO-SOK I Corporation of Japan. The Z-direction gauge of spring 100 is measured at various Z-direction loading levels applied to spring 100 through a circular loading application foot having a diameter of 0.95 inches. The load application foot is connected to the linear gauge detector. The spring 100 and the polyethylene film are placed on the balance, and the balance is adjusted so that it has a reading of zero. The dryness gauge with initial Z-direction of the spring 100 is measured with the loading application foot just touching the spring 100, so that the balance indicates a reading of approximately zero. The Z-directional load on the spring 100 is increased to 32.1 grams in equal increments of about 5, so that the scale indicates a weight of 32.1 grams. The load is then removed, and the unloaded Z-direction dryness gauge of the spring 100 is recorded with the loading application foot just touching the spring 100, so that the balance indicates a reading of approximately zero. For each sample, the difference between the dryness gauge with initial Z-direction and the unloaded Z-direction dryness gauge, between the dryness gauge with initial Z-direction, to obtain the percentage change in the caliber. of dryness of the sample. The reduction of the dryness gauge is the average percentage change in the dryness gauge for the four spring samples. Each spring (and its associated polyethylene sheet) is completely immersed in distilled water for 10 seconds, and then allowed to drain vertically for 10 seconds. Then, the spring 100 and the polyethylene sheet are held on the horizontal surface of the analytical balance, and the balance is adjusted to indicate a reading of zero. The moisture gauge with initial Z-direction of the spring 100 is measured with the load application foot just touching the spring 100, so that the balance indicates a reading of approximately zero. The load with Z-direction in spring 100 is then increased to 32.1 grams in approximately five equal increments. The load is then removed and the unloaded Z-direction moisture gauge of the spring 100 is recorded with the load application foot just touching the spring 100, so that the balance indicates a reading of approximately zero. For each sample, the difference between the moisture gauge with the initial Z-direction and the unloaded Z-direction moisture gauge between the moisture gauge with the initial Z-direction is divided to obtain the percentage change in the gauge. of humidity of the sample. The reduction of the moisture rating of the spring 100 is the average percentage change in the moisture gauge for the four spring samples. In one embodiment, the spring 100 is not absorbent. By "non-absorbent" it is meant that the spring 100 has an absorption capacity of less than 100 percent. The absorption capacity is the proportion of the weight of the water absorbed by a dry sample to the weight of the dry sample. It is believed that a nonabsorbent spring 100 has the advantage that its stiffness and / or its ability to move the core up relatively is not affected by body fluids entering the sanitary napkin 20, as compared to a spring that is absorbent. . The absorption capacity of the spring is measured by first weighing the spring 100 to obtain its dry weight, and then completely submerging the spring 100 in distilled water for 10 seconds. After 10 seconds the spring 100 is removed from the water. The spring is then allowed to drain vertically for 6 seconds. The water adhered to the surface of the spring 100 is then removed by drying it between two pieces of filter paper for 10 seconds. The spring 100 is dried by placing a first piece of filter paper on a dry horizontal surface, placing the spring on the first piece of filter paper, placing a second piece of filter paper on top of the spring to cover the spring, and placing a piece of Plexiglas with a thickness of 0.25 inches that weighs 0.26 pounds on top of the second piece of filter paper to cover the portion of the second piece of filter paper that is over the spring. A suitable filter paper for drying the spring 100 is a filter paper having a relatively smooth surface, a particle retention size of more than about 20-25 microns, and a Herzberg filtration rate of about 37 seconds, in where the filtration rate is the time for 100 milliliters of filtered water to pass through a piece of 10.0 square centimeters of filter paper, with a constant head pressure of 10 centimeters of water. A suitable filtration paper is the Whatman 4 filtration paper manufactured by Whatman Ltd. of England and available with the Fisher Scientific Company of Pittsburgh, Pa. After drying the spring 100 for 10 seconds, the spring 100 is immediately weighted to obtain the weight of the wet sample. The dry weight of the wet weight is subtracted to give the grams of water absorbed by the dry sample. The percentage of absorption capacity is obtained by dividing the grams of water absorbed by the weight of the dry sample, and multiplying the quotient by 100. In a preferred embodiment, the spring 100 is hydrophobic. A surface is hydrophobic if the contact angle between a liquid and the surface is greater than 90 degrees. The American Chemical Society's publication "Contact Angle, Wettability, and Adhesion," edited by Robert F. Gould and protected by copyright in 1964, is hereby incorporated by reference for the purpose of demonstrating how the angle of origin can be determined. Contact. In a preferred embodiment, the spring 100 includes a filament spring. By the term "filament spring" it is meant that the spring 100 includes one or more thin spring sections, each spring section having a length dimension L (Figure 5) at least 10 times, and preferably at least 100 times its maximum transverse dimension D. Each spring section may include a plastic monofilament construction having a generally round cross section, such as a nylon monofilament with a diameter D of between about 0.010 inches and about 0.10 inches, and more preferably between approximately 0.015 inches and approximately 0.030 inches. A cross section of generally round filament is desirable to eliminate sharp edges that might otherwise cause discomfort for the wearer, although other cross sections may be used. Suitable plastic monofilaments are commercially available as Berkley TRILENE XT 25 lbs. And 40 lbs., Manufactured by the Berklay Outdoor Technologies Group of Spirit Lake, Iowa. Referring to Figures 1-5, the filament spring 100 may include a three dimensional network when the sanitary napkin 20 is in the extended position shown in Figures 3-5. The spring 100 may include two legs 102 and 104, which preferably are not parallel as seen along the longitudinal axis of the sanitary napkin 20, when the sanitary napkin is in the extended position. The legs 102 and 104 may be attached to the absorbent core 26 in a first position 111 along the longitudinal centerline 29 of the sanitary napkin 20. The legs 102 and 104 may be attached to the backsheet 24 in the laterally spaced positions. second and third 113 and 115, respectively. The legs 102 and 104 can be attached to the absorbent core 26 in the first position 111 and the backing sheet 24 in the second and third positions 113 and 115 by any suitable method, including but not limited to adhesive bonding, mechanical bonding, ultrasonic bonding. , and thermal bonding. Suitable adhesives for attaching legs 102 and 104 to back sheet 24 and absorbent core 26 include an adhesive tape available from Anchor Continental, Inc., 3 Sigma Division, Covington, Ohio, and Century Adhesive A305 -IV by Century Adhesives Corp., of Columbus, Ohio. In one embodiment the two legs 102 and 104 are formed from a continuous piece of filament. Alternatively, the legs 102 and 104 may be separate pieces that are spaced apart in the lateral direction. Figure 9 shows a spring 100 that includes two separate pieces of filament forming two laterally spaced legs 102 and 104. The legs 102 and 104 are attached to the core 26 in first laterally spaced positions 111A and 111B, respectively, and are attached to the sheet of backup in the second and third positions 113 and 115, respectively.

The second and third positions 113 and 115 are preferably positioned symmetrically with respect to the longitudinal centerline 29 of the sanitary napkin 20. The legs 102 and 104 may by the same shape form an inverted V-shape, as seen from FIG. along the longitudinal axis 29, when the sanitary napkin is in the extended position shown in Figures 3-5. The inverted V-shape of the legs 102 and 104 provides a frame-like tent structure that displaces the portions of the topsheet 22 and the core 26, along the longitudinal centerline 29 from the backsheet 42, and convexly forming the surface facing the body 23 of the upper sheet 22, along the longitudinal center line 29. The legs 102 and 104 preferably form an included angle A (Figure 3) of between about 5 degrees and about 85 degrees with a line parallel to the lateral centerline 31, when the sanitary napkin 20 is in the extended position shown in Figures 3-5. The legs 102 and 104 preferably form an included angle B (Figures 3 and 9) with the Z axis less than 90 degrees, and more preferably less than 60 degrees. The frame-like tent structure of the spring 100 is compressible so that the legs 102 and 104 rest substantially in a plane generally perpendicular to the Z-direction under a Z-direction compressive load (e.g. load 200), as shown in FIG. shows in Figure 2, thereby reducing angle A to approximately zero degrees. The inverted V-shape of the spring 100 can also provide additional Z-directional displacement of the topsheet 22 and the core 26 relative to the backsheet 24, in response to forces directed laterally inward, exerted by the legs. of the user. The forces directed laterally inward, exerted by the legs of the wearer, may cause the portion of the legs 102 and 104, attached to the backsheet 24 in the second and third positions 113, 115, to move laterally inwardly ( towards the longitudinal centerline 29) one relative to the other. That laterally inward movement of the legs 102 and 104 causes the inverted V shape of the spring 100 to narrow in the lateral direction, thereby reducing the angle B to approximately zero degrees. This lateral narrowing of the spring 100 causes the spring 100 to increase the force exerted on the core 26 and the top sheet 22 in the Z direction. The spring 100 can, thereby, provide additional displacement with a Z-direction of the sheet 22 and the core 26 relative to the backing sheet 24, when the spring 100 is laterally compressed. This laterally inward movement of the legs 102 and 104 also allows the topsheet 22 and the core 26 to be compressed to have a relatively thin lateral gauge, at relatively low lateral load levels, to promote the top sheet and core to be conform with the user's body in the areas of the lips, perianal, and / or gluteal groove. The leg 102 preferably includes a first arcuate segment 103 that extends between the first position 111 and the second position 113. The leg 104 preferably includes a second arcuate segment 105 that extends between the first position 111 and the third position 115. The arcuate segments 103 and 105 are positioned symmetrically with respect to the longitudinal center line 29 so that the spring 100 provides restoration forces that are symmetrical with respect to the longitudinal centerline 29. The arcuate segments 103 and 105 provide the legs 102 and 104 flexibility to facilitate deflection of spring 100 from the extended position shown in Figure 3 to the compressed position shown in Figure 2. Arched segments 103 and 105 also provide flexibility in the longitudinal direction, and by the same allows a relative longitudinal movement of the upper sheet 22 and the core 26 in relation to the backing sheet 24. The arched segments 103 and 105 preferably subtend an angle of at least 90 degrees, and more preferably an angle of at least 180 degrees. In a preferred embodiment each leg 102 includes one or more closed turns 106 attached to the core 26 and the backing sheet 24 in diametrically opposed positions 111 and 113, and each leg 104 includes one or more closed turns 108 attached to the core 26 and the sheet of backing 24 in diametrically opposed positions 111 and 115. Closed turns 106 and 108 preferably have a generally circular or oval ring shape. The stiffness with Z-direction and the Z-directional elevation of the spring 100 can be varied by varying the size of the closed turns 106 and 108, and by lateral spacing of the positions 113 and 115 to which the turns are attached. closed 106 and 108 to the backing sheet 24. The Z-direction stiffness of the spring 100 will generally decrease as the circumference of the closed turns 106 and 108 increases. For a given circumference of the turns 106 and 108, the stiffness with Z direction and the Z-directional elevation of spring 100 will decrease as the lateral spacing of positions 113 and 115 decreases. Closed turns 106 and 108 preferably have a circumference of at least 5.1 centimeters (2.0 inches), and more Preferably they have a circumference of between about 7.6 centimeters (3.0 inches) and about 20.3 centimeters (8.0 inches). The closed turns 106 and 108 are preferably attached to the backsheet 24 at the second and third positions 113 and 115, respectively, which are spaced apart laterally a distance of between about 1.0 centimeters and about 5.0 centimeters, as measured with the backsheet 24 extended in a generally planar configuration, as shown in Figure 3. Additionally, the stiffness with Z-direction of spring 100 can be varied in other ways, such as by varying the dimension D, by variation of the material from which the spring 100 is formed, and by providing multiple closed turns 106 and 108 to form the spring legs 102 and 104, respectively. The legs 102 and 104 can be overlapped in a scissor-like configuration as shown in Figures 1 and 5 to facilitate deflection of the spring 100 from the extended position shown in Figure 3 to the compressed position shown. in Figure 2. The sanitary napkin 20 having a spring 100 with the legs 102 and 104 can be characterized because it has a stiffening with a Z direction that decreases while the Z-direction gauge decreases from Zl in Figure 3 to Z2 in Figure 2. The stiffness with Z-direction is the change in force with Z-direction required to produce a displacement unit with Z-direction of the top sheet 22 relative to the back-up sheet 24. Without being limited by theory, it is believed that the resistance that legs 102 and 104 provide to Z-directional compression decreases while angle A (Figure 3) decreases. Accordingly, the wearer's comfort is maintained while the sanitary napkin 20 is compressed from the extended position shown in Figure 3 to the compressed position shown in Figure 2. Of course, once the the spring 100 has been flattened, the Z-direction stiffness of the sanitary napkin 20 will increase with additional displacement of the topsheet 22 relative to the backsheet 24. Referring to Figure 6, a sanitary napkin 20 having side ends front and rear 30A, 30B may have a plurality of springs 100 such as springs 100A, 100B, and 100C, positioned along the longitudinal axis 29. The springs 100A-C are shown as dotted lines in Figure 6 and are arranged from front to back of the sanitary napkin 20 respectively. The spring 100A can provide the conformation of the upper sheet 22 with the user's perianal groove, and the spring 100C can provide the conformation of the upper sheet 22 with the gluteal groove of the wearer. As shown in Figure 6, the core 26 can be segmented to compress a plurality of core segments 26A, 26B, and 26C which independently move in the Z direction. At least one spring 100 can be associated with each segment of core 26A-C to provide Z-directional displacement independent of core segments 26A-C related to backsheet 24. Adjacent segments of the core, such as core segments 26A, B and 26B, can be joined. , C by laterally extending the hinge lines 27. The hinge lines 27 may include, but are not limited to relief or compression lines, folds, notch lines or pre-bent lines. Alternatively, the adjacent segments of the core 26A, B and 26B, C can be disengaged and indirectly joined to one another by the top sheet 22. A sanitary napkin 20 including the filament spring 100 can have a first gauge with Z-direction Zl to a Z-direction compression load of 2 grams, and a second gauge with Z-direction Z2 to a Z-direction compression load of less than 100 grams, where the second gauge with direction in Z it is at least 15 millimeters smaller than the first caliber with Z Zl direction. More preferably, the second gauge with Z-direction is at least 15 mm smaller than the first gauge with Z-direction at a Z-direction compression load of less than 50 grams. More preferably, the second gauge with Z-direction is at least 15 millimeters smaller than the first gauge with Z-direction at a compression load of less than 25 grams.

A sanitary napkin 20 including the filament spring 100 may also have a first gauge with Z-direction Zl to a compression load with Z-direction of 2 grams, and a second gauge with Z-direction Z2 of at least 25 mm less that the first gauge with Z-direction Zl to a Z-direction compression load of less than 100 grams. More preferably, the second gauge with Z-direction is at least 25 millimeters smaller than the first gauge with Z-direction at a Z-direction compression load of less than 50 grams. The filament spring 100 also provides a sanitary napkin 20 having a gauge with Z-direction of less than 10 millimeters, and preferably less than 5 millimeters, under a Z-direction compression load of 90 grams. The filament spring can thereby promote body conformation and user comfort by keeping the topsheet in contact with the wearer's body, while providing a relatively low resistance to compression of the sanitary napkin in the direction of Z. A sanitary napkin 20 having the filament spring 100 may have a lateral gauge of less than 10 millimeters under a lateral compression load of 100 grams, more preferably a lateral gauge of less than 5 millimeters under a lateral compression load. of 300 grams, and more preferably a lateral gauge of less than 3 millimeters under a compression load of 1000 grams. The filament spring allows by the same that a portion of the upper sheet and the core are laterally compressed at relatively low lateral load levels, thereby promoting the conformation of the upper sheet and the core with the wearer's body in the areas of the lips, perianals, and / or gluteal groove while maintaining the comfort of the user simultaneously. Figure 7 shows a sanitary napkin 20 having three filament springs, a forward spring 100A, a middle spring 100B, and a rear spring 100C. A sanitary napkin 20 having the spring configuration shown in Figure 7 was used to provide the data in Tables 1-4. A description of the filament springs 100A-C and a description of the procedure for obtaining the data in Tables 1-4 are provided below. Referring to Figure 7, the spring 100A is longitudinally spaced a distance 131 of approximately 75 millimeters from the front side end 262 of the absorbent core 26 having a longitudinal length of approximately 23 centimeters (in Figure 7 the front and rear ends are indicated). laterals 262 and 264). Legs 102 and 104 include two turns 106 and 108, respectively, of the Berkley Truene XT monofilament of 25 pounds. Each of the turns 106 and 108 have a circumference of approximately 15.2 centimeters (6.0 inches). The legs 102 and 104 are attached to the backing sheet 104 in the second and third positions 111 and 113 laterally spaced a distance 121 equal to approximately 30 millimeters. The legs 102 and 104 are joined to the core 26 in the first position 111, which is located on the longitudinal centerline 29. The spring 100B has substantially the same construction as the spring 10OA, and is spaced longitudinally towards the rear of the spring 100A a distance 151 equal to approximately 70 centimeters. The spring 100C is spaced longitudinally towards the rear of the spring 100B a distance 171 equal to approximately 55 millimeters. The spring 100C has a leg 102 that includes a single turn 106 of the Berkley Truene XT monofilament of 25 pounds. The spring 100C has a leg 104 that includes a single turn 108 of the 25 pound Berkley Truene XT monofilament. Each of the turns 106 and 108 have a circumference of about 12.7 centimeters (5.0 inches). The legs 102 and 104 are attached to the backsheet 24 in the second and third positions 113 and 115 laterally spaced a distance 161 equal to approximately 15 millimeters, and the legs 102 and 104 are joined to the core 26 in the first position 111 which is located on the longitudinal center line 29. The calibres with Z-direction, Zl and Z2 and the corresponding Z-direction compression loads are prepared. in Tables 1-3 where they were measured using the following procedure with an INSTRON tensile tester, Model 4502, manufactured by Instron Engineering Corp., of Canton, Mass. To be tested the sanitary napkins 20 must be conditioned during approximately 2 hours in a room with a temperature between 71 and 75 degrees Fahrenheit and 48 to 52 percent relative humidity before the test. The traction test machine is equipped with a 100 gram load cell. The toallja. sanitary 20 is held, with the topsheet 22 facing upwards with the garment facing surface 25 of the backsheet 24 downward and resting on a horizontal surface of a 6-inch diameter plate attached to the fixed jaw of the tensile testing machine. A 1.0 inch diameter hox horizontal compression foot is attached to the movable head crossarm of the tensile testing machine to face the top sheet 22 of the sanitary napkin 20. The compression foot is placed along the center line longitudinal 29 of the sanitary napkin 20. The data in Table 1 (Front) were measured with the compression foot placed approximately on the spring 100A, the data in Table 2 (Center) were measured with the compression foot positioned approximately the spring 100B, and the data in Table 3 (Rear) were measured with the compression foot positioned approximately on the spring 100C. The spacing with initial Z-direction between the surface of the fixed plate and the compression foot is greater than the zero-direction gauge without load of the sanitary napkin 20, and is at least 40 millimeters. The compression foot is then advanced to the surface of the fixed plate at a constant rate (head crosshead speed) of 10 inches per minute. The force measured by the load cell is recorded for a given spacing between the compression foot and the surface of the fixed plate in a tape recorder at a graph speed of 20 inches per minute. The spacing between the compression foot and the fixed plate surface under a given load corresponds to the Z-direction gauge of the sanitary pad 20 at that load. When the spacing between the compression foot and the surface of the fixed plate has been reduced - at least 25 millimeters from the spacing under a load of 2 grams, or the measured load is greater than 100 grams, the travel direction is reversed of the compression foot to retract from the fixed plate surface at a rate of 10 inches per minute. Data were obtained in Table 1-3 using the above procedure to measure the Z-direction gauge of five sanitary napkins 20.

TABLE 1 CALIBER AND LOAD WITH FRONT Z DIRECTION Average Measurement S.D. Min MAX A Caliber at 2 gm load: 26.1 mm 1.47 25.0 mm 28.5 mm B Caliber at 2 gm without load: 22.3 mm 1.64 21.0 mm 25.0 mm C Reduced gauge 11.1 mm 1.27 10.0 mm 13.5 mm 15 mm from A D Force in the gauge C 17.9 gm 3.68 14.0 gm 22.0 gm E Caliber reduced 25 mm from A 1.2 mm < l m 3.5 mm F Force in the Caliber E > 100 gm > 100 gm > 100 gm G Caliber at 90 gm load: 3.3 mm 0.27 3.0 mm 3.5 mm TABLE 2 CALIBER AND LOAD WITH DIRECTION IN Z CENTRAL Average Measurement S .D. Min MAX A Caliber at 2 gm load: 30.2 mm 1.48 28.5 mm 32 mm B Caliber at 2 gm without load: 26.1 mm 1.56 24.5 mm 28.5 mm C Reduced gauge 15.2 mm 1.48 13.5 mm 17.0 miti mm from A D Strength in Caliber C 35.1 gm 7.8 23.0 gm 42.0 gm E Caliber reduced 25 mm from A 5.2 itun 1.48 3.5 mm. 7.0 mm F Strength in the Caliber E 38.6 gm 12.5 25.5 gm 48 mm G Caliber at 90 gm load; 3.4 mm 0.55 3.0 mm 4.0 mm TABLE 3 CALIBER AND LOAD WITH DIRECTION IN Z REAR Average Measurement S.D. Min MAX A Caliber at 2 gm load: 30.7 m 1.20 29.5 mm 32 mm B Caliber at 2 gm without load: 24.5 mm 1.80 22.0 mm 26.5 mm C Gauge reduced 15.7 mm 1.20 14.5 mm 17.0 mm 15 mm from A D Strength in Gauge C 21.9 gm 2.72 18.0 gm 24.5 gm E Reduced gauge 25 mm from A 5.7 mm 1.20 4.5 m 7.0 mm F Force in the Caliber E 33.8 gm 12.0 21 gm 49.5 gm G Caliber at 90 gm load: 3.5 mm 0.35 3.0 mm 4.0 mm Tables 1-3 list the average, standard deviation, minimum, and maximum of AG measurements for five sanitary napkins 20 having springs 100A-C shown in Figure 7. Measure A is the gauge with address in Z of the sanitary napkin 20 at a load cell reading of 2 grams, while the compression foot is advancing towards the surface of the fixed plate. The caliber at a load of 2 grams is essentially the caliber Zl of a sanitary napkin without loading. Measure B the gauge with Z direction of the sanitary napkins 20 to a load cell reading of 2 grams, while the compression foot is retracting from the surface of the fixed plate, and shows that the springs 100A-C substantially restore the original caliber, without load of the sanitary napkin 20 on the removal of the load with Z direction. The measure C corresponds to a second Z2 caliber which is 15 millimeters smaller than the caliber Zl at a load of 2 grams, and the measure D is the compression force with Z direction in the C gauge. The E measure corresponds to a second Z2 gauge which is 25 millimeters smaller than the Zl gauge at a load of 2 grams, and the measure F is the compressive force with Z-direction measured in gauge E. Measure G is the gauge with Z-direction of sanitary napkin 20 when the compression force with Z-direction is equal to 90 grams. In Table 1, the force in the caliber E exceeded 100 grams because the spring 100A was substantially flattened in that caliber. Figure 10 is a graph showing the Z-directional force measured by the tensile tester as a function of the Z-direction gauge of a sanitary napkin 20 as shown in Figure 7 and as measured on the spring central 100B. The portion of the graph labeled 501 in Figure 10 shows the force-gauge relationship as the compression foot advanced toward the surface of the fixed plate. The portion of the graph labeled 503 in Figure 10 shows the force-gauge relationship as the compression foot retracted from the surface of the fixed plate. The portion of the chart labeled 501 illustrates that the Z-direction stiffness of the sanitary napkin having a spring 100 may first decrease, and then increase, while reducing the Z-direction gauge of the sanitary napkin. In particular, the portion of the graph labeled 501 shows that the first force increases to a local maximum while the caliber decreases, decreases to a local minimum as the gauge is further reduced, and then increases as the spring 100B is flattened. The lateral gauge of the sanitary napkin and the corresponding lateral load values listed in Table 4 were obtained using the procedure described below, with reference to Figure 8, and with reference to a sanitary napkin 20 having the springs 100A-C that are shown in Figure 7. The sanitary napkins 20 to be tested should be conditioned for about 2 hours in a room at a temperature between 71 and 75 degrees Fahrenheit and from 48 to 52 percent relative humidity before the proof. The sanitary pad 20 is laterally compressed using a constant index of a tensile / compression tester such as an EME tester model 599A available from EME, Inc., of Newbury, Ohio. The tester should use a load cell with a sensitivity of at least 5 grams and have a load range of at least 2000 grams. The load cell must be calibrated so that the force measurements are accurate to within 2 percent by force measurement greater than 100 grams. The measurement of the position testers must be accurate to within at least 0.05 centimeters. A microcomputer can be used, such as an IBM compatible personal computer that has an 80386 microprocessor to control the tester and acquire the data during the test. The tester and the microcomputer can be purchased as an EME, Inc. system. A first circular plate 322 having a first surface 323 with a diameter of 40 millimeters is attached to the moving head crosshead of the tester. A second circular plate 324 having a second surface 325 with a diameter of 40 millimeters is fastened to the staple of the fixed load cell 326. Plates 322 and 324 are attached to the moving head crosshead and to the load cell of such so that surfaces 323 and 325 are horizontal and parallel. The surfaces 323 and 325 are initially spaced a distance of at least 37.5 millimeters. The sanitary napkin 20 is partially folded along the longitudinal axis 29 to form a V-shaped figure, with the surface facing the body 25 of the convexly formed upper sheet. The sanitary napkin 20 is bent the minimum amount necessary to allow at least a portion of the topsheet 22 and the absorbent core 26 to be placed between the surfaces 323 and 325. The folds of the topsheet 22 or the core 26 must be removed. before activating the head crosshead. Preferably the back sheet 24 and the wings 44 are pulled out from the absorbent core 26 so that they are not placed between the surfaces 323 and 325. The side ends 30 of the sanitary napkin 20 can be held while the sanitary napkin 20 is resting on the surface 325, to prevent the springs 100A-C from causing the sanitary napkin to be unfolded and falling from between the surfaces 323 and 325. Thereafter the tester is activated to advance from the surface 323 to the surface 325. While that the surface 323 advances towards the surface 325 the support can be released at the lateral ends 30. The surface 323 is advanced towards the surface 325 at a constant index of .158 centimeters / second. While the surface 323 advances toward the surface 325 the top sheet 22 and the core 26 must be bent so that two layers of the top sheet 22 and the core 26 are placed between the surfaces 323 and 325, as shown in the Figure 8 with at least a portion of the springs 100 compressed between the two layers of the core and the two layers of the upper sheet. The force and displacement values are displayed at a range of at least 40 data points per second. The lateral gauge of the sanitary napkin (the distance between surfaces 323 and 325) is recorded at lateral force levels of 50, 100, 300, 1000, and 2000 grams. The lateral gauge and the corresponding lateral force measurements were taken for at least three sanitary napkins. The average of the lateral gauge reading is reported for three sanitary napkins in each of the 50, 100, 300, 1000, and 2000 grams lateral force levels in Table 4.

TABLE 4 CALIBER AND LATERAL LOAD Average Measure S. D.

Caliber at 50 gm 9.3 mm 0.0 Caliber at 100 gm 6.1 mm 0.0 Caliber at 300 gm 3.8 mm 0.01 Caliber at 1000 gm 2.6 mm 0.01 Caliber at 2000 gm 1.9 mm 0.01 While particular embodiments of the present invention have been illustrated and described, the scope of the present invention is defined by the appended claims.

Claims (34)

NOVELTY OF THE INVENTION Having described the above invention, it is considered as a novelty, and therefore, the content of the following is claimed as property: CLAIMS

1. A disposable absorbent article having a longitudinal centerline and longitudinal ends joining first and second side ends, the absorbent article includes: a liquid permeable top sheet having a body facing surface; a liquid-impermeable backing sheet attached to the top sheet; and an absorbent core placed in the middle of the upper sheet and the backing sheet; the disposable absorbent article has a first gauge with Z-direction under a Z-direction compression load of 2 grams and a second Z-direction gauge under a Z-direction compression load of less than 100 grams, wherein the The second caliber with Z direction is at least 15 millimeters smaller than the first caliber with Z direction.

2. The disposable absorbent article, according to claim 1, characterized in that it has a second gauge with Z-direction under a Z-direction compression load of less than 50 grams; wherein the second gauge with Z-direction is at least 15 mm smaller than the first gauge with Z-direction.

3. The disposable absorbent article, according to claim 2, characterized in that it has a second gauge with direction in Z under a Z-direction compression load of less than 25 grams; wherein the second gauge with Z direction is at least 15 mm smaller than the first gauge with Z direction.

4. A disposable absorbent article having a longitudinal centerline and longitudinal ends joining the first and second transverse ends, the absorbent article includes: a liquid-permeable upper sheet having a surface facing the body; a liquid-impermeable backing sheet attached to the top sheet; and an absorbent core placed in the middle of the upper sheet and the backing sheet; the disposable absorbent article has a first gauge with Z-direction under a Z-direction compression load of 2 grams and a second Z-direction gauge under a Z-direction compression load of less than 100 grams, wherein the second gauge with Z-direction is at least 25 mm smaller than the first gauge with Z-direction. The disposable absorbent article, according to claim 4, characterized in that it has a second gauge with Z-direction under a Compression load with Z direction less than 50 grams; wherein the second gauge with Z-direction is at least 25 mm smaller than the first gauge with Z-direction. 6. The disposable absorbent article, in accordance with claim 5, characterized in that it has a gauge with Z-direction. of less than 10 millimeters under a compression load with Z direction of 90 grams. 7. The disposable absorbent article, according to claim 6, characterized in that it has a gauge with a Z-direction of less than 5 millimeters under a compression load with Z-direction of 90 grams. The disposable absorbent article, according to claim 1, characterized in that it has a lateral gauge of less than 10 millimeters under a lateral compression load of 100 grams. The disposable absorbent article, according to claim 1, characterized in that it has a lateral gauge of less than 5 millimeters under a side compression load of 300 grams. 10. The disposable absorbent article, according to claim 1, characterized in that it has a lateral gauge of less than 3 millimeters under a lateral compression load of 1000 grams. 11. A disposable absorbent article having a longitudinal centerline and longitudinal ends joining first and second side ends, the absorbent article includes: a liquid-permeable top sheet having a surface facing the body; a backing sheet impervious to liquid having a surface facing the garment, the backing sheet is attached to the top sheet; an absorbent core placed in the middle of the upper sheet and the backing sheet; and a nonabsorbent spring positioned in the middle of the absorbent core and the backsheet to provide a Z-direction elastic displacement of a portion of the top sheet relative to the backsheet. The disposable absorbent article, according to claim 11, wherein the spring convexly forms a portion of the surface facing the body of the topsheet along the longitudinal center line of the absorbent article. 13. The disposable absorbent article, according to claim 12, wherein the spring provides an elastic displacement with Z direction of a portion of the surface facing the body of the upper sheet in relation to the surface that gives towards the garment of the backing sheet of at least 15 millimeters. The disposable absorbent article, according to claim 11, wherein the absorbent core and the topsheet are joined to be displaced by the spring as a unit, and wherein the top sheet is attached to the sheet backrest to provide a Z-directional movement independent of the top sheet and the absorbent core in relation to the back sheet. 1

5. The disposable absorbent article, according to claim 14, wherein the topsheet is attached to the backsheet to provide a longitudinal uncoupling of the movement of the topsheet and the absorbent core relative to the topsheet. back. 1

6. The disposable absorbent article, according to claim 14, characterized in that it also includes at least one longitudinally extending fold that joins the upper sheet to the backing sheet to control the separation of the upper sheet from the backup sheet. The disposable absorbent article, according to claim 11, wherein the upper sheet and the absorbent core have a Taber stiffness-flex combination in each of the longitudinal and lateral directions of less than 2 grams-centimeters . 18. The disposable absorbent article, according to claim 11, wherein the absorbent core is segmented to provide at least two independently displaceable core segments with Z direction, and the absorbent article has at least one spring associated with each of the two segments of the nucleus. 19. The disposable absorbent article, according to claim 11, characterized in that it has a first caliber with Z-direction under a compression load with Z-direction of 2 grams and a second caliber with Z-direction under a load. of compression with Z-direction of less than 100 grams, where the second caliber with Z-direction is at least 15 millimeters smaller than the first caliber with Z-direction. The disposable absorbent article, in accordance with that claimed in claim 19, characterized in that it has a second gauge with Z-direction under a Z-direction compression load of less than 50 grams; wherein the second gauge with Z-direction is at least 15 mm smaller than the first gauge with Z-direction. 21. The disposable absorbent article, according to claim 20, characterized in that it has a second gauge with direction in Z under a Z-direction compression load of less than 25 grams; wherein the second gauge with Z-direction is at least 15 mm smaller than the first gauge with Z-direction. 22. The disposable absorbent article, according to the claim in claim 11, characterized in that it has a first caliber with Z-direction under a compression load with Z-direction of 2 grams and a second caliber with Z-direction under a compression load with Z direction. less than 100 grams, wherein the second gauge with Z-direction is at least 25 mm smaller than the first gauge with Z-direction. 23. The disposable absorbent article, in accordance with claim 22, characterized in that it has a second gauge with Z-direction under a Z-direction compression load of less than 50 grams; wherein the second gauge with Z-direction is at least 15 mm smaller than the first caliber with Z-direction. 24. The disposable absorbent article, in accordance with claim 18, characterized in that it has a gauge with Z-direction. of less than 10 millimeters under a compression load with Z direction of 90 grams. 25. The disposable absorbent article, according to claim 19, characterized in that it has a caliber with Z direction of less than 5 millimeters under a load of. compression with Z direction of 90 grams. 26. The disposable absorbent article, according to claim 19, characterized in that it has a lateral gauge of less than 10 millimeters under a lateral compression load of 100 grams. 2

7. The disposable absorbent article, according to claim 19, characterized in that it has a lateral gauge of less than 5 millimeters under a side compression load of 300 grams. 2

8. The disposable absorbent article, according to claim 19, characterized in that it has a lateral gauge of less than 3 millimeters under a lateral compression load of 1000 grams. 2

9. The disposable absorbent article, according to claim 11, characterized in that it has a Z-direction stiffness which first decreases, and then increases, while reducing the Z-direction gauge of the disposable absorbent article. 30. A disposable absorbent article having a longitudinal centerline and longitudinal ends joining first and second side ends, the absorbent article includes: a liquid-permeable top sheet having a body facing surface; a backing sheet impervious to liquid having a surface facing the garment, the backing sheet is attached to the top sheet; an absorbent core placed in the middle of the upper sheet and the backing sheet; a filament spring positioned in the middle of the upper sheet and the backing sheet to provide a Z-directional elastic shift of a portion of the upper sheet relative to the backing sheet, and to convexly form a portion of the surface which faces the body of the upper sheet along the longitudinal centerline of the absorbent article. 31. The disposable absorbent article, according to claim 30, wherein the filament spring is positioned between the absorbent core and the backsheet. 32. The disposable absorbent article, according to claim 30, wherein the filament spring includes non-parallel first and second legs, each leg forms an angle comprised of less than 90 degrees with a line parales to the Z direction. when the disposable absorbent article is in an extended position. 33. The disposable absorbent article, according to claim 32, wherein each leg is attached to the absorbent core in a first position along the longitudinal centerline of the disposable absorbent article. 34. The disposable absorbent article, according to claim 33, wherein each leg is attached to the back sheet in the second and third laterally spaced positions positioned symmetrically with respect to the longitudinal centerline of the disposable absorbent article. 35- The disposable absorbent article, according to claim 32, wherein the filament spring includes spaced apart first and second legs in the lateral direction, each leg is attached to the core at laterally spaced locations, and wherein the legs are spaced apart from one another. legs are attached to the backsheet in laterally spaced positions symmetrically positioned with respect to the longitudinal centerline of the disposable absorbent article. 36. The disposable absorbent article, in accordance with claim 32, wherein each leg includes an arcuate segment. 37. The disposable absorbent article, according to claim 30, wherein the filament spring includes: a closed first turn attached to the absorbent core in a first position generally aligned with the longitudinal centerline of the disposable absorbent article and joined with the backsheet in a second position spaced laterally from the longitudinal center line; and a closed second loop attached to the absorbent core in a first position generally aligned with the longitudinal centerline of the disposable absorbent article and joined with the backsheet in a third position laterally spaced from the longitudinal center line; wherein the first and second closed turns form a V-shaped figure as seen along the longitudinal centerline of the disposable absorbent article. 38. A disposable absorbent article having a longitudinal center line and longitudinal ends joining first and second side ends, the absorbent article includes: a liquid permeable top sheet having a body facing surface; a backing sheet impervious to liquid having a surface facing the garment, the backing sheet is attached to the top sheet; an absorbent core placed in the middle of the upper sheet and the backing sheet; and a spring positioned in the middle of the upper sheet and the backing sheet to provide a Z-directional elastic shift of a portion of the upper sheet relative to the backing sheet, the spring has a reduction in moisture gauge of no more than about 8 percent. 39. A disposable absorbent article having a longitudinal centerline and longitudinal ends joining first and second side ends, the absorbent article includes: a liquid-permeable top sheet having a surface facing the body; a backing sheet impervious to liquid having a surface facing the garment, the backing sheet is attached to the top sheet; an absorbent core placed in the middle of the upper sheet and the backing sheet; and a spring positioned in the middle of the absorbent core and backing sheet to provide a Z-directional elastic shift of a portion of the upper sheet relative to the backing sheet, the spring has a reduction in moisture gauge which it is no more than about 20 percent greater than the reduction in dryness rating of the spring. IN WITNESS WHEREOVER, I sign the above in Mexico City, D.F., on the 20th day of the month of December 1994. By THE PROCTER & GAMBLE COMPANY