Article having a non-absorbent resilient layer

An absorbent article, such as a sanitary napkin, has an absorbent and a substantially non-absorbent resilient layer adjacent to the absorbent. The absorbent is sufficiently stiff to resist twisting of the absorbent article during use. The resilient layer is sufficiently resilient to resist bunching during use. As a result, the absorbent article resists both twisting and bunching. The absorbent article has zones which vary in caliper, stiffness and absorbency. A central absorbent zone is thickest in caliper, more absorbent than the other zones and is stiffer than the other zones. An adjacent zone is less thick in caliper, less absorbent and less stiff. A peripheral zone, located near the outer side edges, is least thick in caliper, least absorbent and least stiff.

FIELD OF THE INVENTION 
This invention relates to an absorbent article, such as a sanitary napkin. 
More specifically, this invention relates to an absorbent article which 
has a substantially non-absorbent, substantially resilient layer to resist 
bunching during use. 
BACKGROUND OF THE INVENTION 
The term "absorbent article" relates to products such as sanitary napkins, 
incontinent products, diapers, panty liners, training pants and the like. 
Sanitary napkins, also referred to as catamenial or feminine pads, are 
designed to be worn by a female to absorb medium to heavy flow of body 
fluids such as menses, blood, urine, and other excrements discharged by 
the body during a menstrual period. Sanitary napkins are external devices 
which are designed to be aligned approximate to the pudendum region of the 
human body and are generally held in position by being adhesively or 
mechanically attached to an undergarment. Such products differ from 
tampons which are classified as internal devices and are designed to be 
physically inserted into the vaginal cavity. Sanitary napkins also differ 
from pantiliners and panty shields in several noticeable ways. Most 
sanitary napkins are generally larger in size, have a more defined 
three-dimensional configuration, are thicker in caliper and are bulkier in 
appearance than pantiliners or panty shields. Functionally, sanitary 
napkins are different in that they are constructed to absorb a greater 
quantity of body fluid and are designed so that they can be worn for a 
longer period of time, for example, overnight if needed. 
Since sanitary napkins are normally used during the major discharge portion 
of a menstrual period, they are constructed to handle medium to heavy 
flows and commonly have a total absorbent capacity in the range of about 
20 to 50 grams of fluid. Pantiliners and panty shields, on the other hand, 
are designed to absorb relatively small amounts of body fluids and are 
marketed to be used at the beginning and end of a menstrual period when 
flow is light or spotty. Commercially available pantiliners and panty 
shields are constructed to have a total absorbent capacity in the range of 
about 1 to 15 grams of fluid. 
Today's sociological changes have led to more women becoming active in 
sports and other types of physical activity. These changes have been 
accompanied by a change in attire and have led to more women wearing 
tight, body-fitting clothing. Most current sanitary napkins, having a 
caliper of 6.4 mm. or greater, can present an unsightly bulge adjacent the 
pudendum when worn inside tight-fitting shorts or pants. The overall size 
and configuration of the napkin can also restrict leg movement or cause 
discomfort when a woman participates in physical or sporting events. In 
view of this, there is a real need to provide an improved thin sanitary 
napkin which is less than about 5 millimeters in caliper and resists 
bunching and twisting when worn. 
In providing a thin sanitary napkin less than about 5 millimeters in 
caliper, it was found that such products had a tendency to bunch and twist 
when worn. The squeezing of the napkin between the thighs and the 
resulting deformation as a woman moves about, causes the upper surface of 
the napkin to acquire a curved or convex shape. The twisting is sometimes 
referred to as "roping" because of twisting along a longitudinal axis that 
imparts a cylindrical profile to the sanitary napkin. The roping effect is 
detrimental because the napkin is unable to absorb body fluid that 
contacts its upper surface. The fluid discharged from the vagina has a 
tendency to run off the roped napkin before it can be absorbed by the 
primary absorbent means in the sanitary napkin and, therefore, the fluid 
leaks on an adjacent undergarment. This run-off becomes significant during 
periods of heavy flow. Such bunching and twisting is more of a problem in 
thin sanitary napkins than in thicker napkins. 
Other people have recognized the need for a thin sanitary napkin. See, for 
example: U.S. Pat. Nos. 4,217,901 to Bradstreet et al.; 4,950,264 and 
5,009,653 to Osborn; and U.S. Pat. No. 5,248,309 to Serbiak et al. 
assigned to the same owner as this Patent Application. 
SUMMARY OF THE INVENTION 
This invention relates to an absorbent article such as a sanitary napkin 
which has a central longitudinal axis. The absorbent article has an 
absorbent means and a substantially nonabsorbent, substantially resilient 
layer or member adjacent to the absorbent means. The absorbent means has a 
central longitudinal axis substantially aligned along the central 
longitudinal axis of the absorbent article. The absorbent article may also 
have a liquid pervious cover sheet. In addition, the absorbent article may 
have a liquid impervious backing sheet or baffle. The absorbent means is 
sufficiently stiff to resist twisting of the absorbent article during use. 
The resilient layer has a width within the range of from 60 percent to 100 
percent of the total width of the absorbent article and is sufficiently 
resilient to resist bunching of the absorbent article during use. The 
absorbent means may be located between the cover sheet and the 
substantially resilient layer. The resilient layer has a Circular Bend 
Flex in the range of from about 9 to about 42 grams. The absorbent means 
has a Gurley stiffness in the range of from about 782 milligrams to about 
2526 milligrams. Desirably, the absorbent article has a total width that 
spans the width of the labia majora of the user. 
For absorbent articles such as sanitary napkins, the sanitary napkin may 
also have a transfer layer, one or more tissue layers, a garment adhesive 
on the garment-facing side of the sanitary napkin and a peel strip over 
the garment adhesive and adapted to be removed before use to expose the 
garment adhesive. In one embodiment, the sanitary napkin has a liquid 
pervious cover sheet, a substantially liquid impervious backing sheet, an 
absorbent means, and a substantially nonabsorbent, substantially resilient 
layer disposed between the absorbent means and the backing sheet. The 
backing sheet is at least partially peripherally joined to the cover 
sheet. The sanitary napkin has a total width transverse to the 
longitudinal axis which is defined by the distance from one outer side 
edge of the sanitary napkin to the opposite outer side edge of the 
sanitary napkin of the body-facing side of the napkin. 
The absorbent means has a longitudinal central axis substantially aligned 
along the longitudinal central axis of the sanitary napkin. The absorbent 
means is sufficiently stiff to resist twisting of the sanitary napkin 
during use. The resilient layer is disposed between the absorbent means 
and the backing sheet. The resilient layer has a width within the range of 
from 60 percent to 100 percent of the total width of the sanitary napkin 
and is sufficiently resilient to resist bunching of the sanitary napkin 
during use. The absorbent means may have a width of less than 2.5 inches 
(63.5 millimeters). Alternately, it may have a width of less than 60 
percent of the total width of the body-facing side of the sanitary napkin. 
The sanitary napkin may have a caliper or thickness of less than about 5 
millimeters (mm.). 
One object of this invention is to provide an absorbent article which 
resists twisting and bunching during use. Another object of this invention 
is to provide a thin sanitary napkin which has a central longitudinal 
absorbent zone which is more absorbent and stiffer than adjacent zones, in 
combination with a resilient layer that is substantially non-absorbent. 
Still another object of the present invention is to provide an absorbent 
article that has zones that vary in caliper, stiffness and absorbency. A 
central absorbent zone is thickest in caliper, is more absorbent than any 
of the other zones and is the stiffest of any of the other zones. An 
adjacent zone, which is adjacent to the absorbent zone is less thick in 
caliper, less absorbent and less stiff. A peripheral zone, located near 
the outer side edges, is still less thick in caliper, less absorbent and 
less stiff. 
The invention further includes a method for achieving improved performance 
in a sanitary napkin, including the steps of: providing a substantially 
resilient layer substantially aligned along the central, longitudinal axis 
of the napkin to resist bunching, providing a stiffening means 
substantially aligned along the central, longitudinal axis of said napkin 
and adapted to resist twisting of said napkin, arranging the substantially 
resilient layer so that its width extends across at least 60% of the total 
width of the body-facing surface of the napkin, and selecting for the 
stiffening means a material having comparatively high absorbent capacity 
and adapted to absorb fluid adjacent to the central, longitudinal axis of 
the napkin and thereby reduce flow of fluid toward the outer side edges of 
the napkin to reduce leakage of fluid at the outer side edges of the 
napkin. The method may also include the step of selecting for the 
substantially resilient layer a material that is substantially 
non-absorbent to further reduce leakage at the outer side edges of the 
napkin. 
We have found that the combination of elements in absorbent articles of the 
invention described herein, such as sanitary napkins, provides products 
having unexpectedly good results and achieves a good balance between 
comfort to the user when worn, high absorbency and other good performance 
characteristics and reasonable cost. The products have a softness and 
thinness around the edges that enhance comfort. The products also resist 
twisting, bunching and leakage.

DETAILED DESCRIPTION 
The absorbent article may be a sanitary napkin which is designed to be worn 
by a female to absorb body fluids such as menses, blood, urine, and other 
excrements, such as those discharged during a menstrual period. 
First Embodiment 
Referring to FIGS. 1, 2, and 3, a first embodiment of the sanitary napkin 
15 is about 150 millimeter (mm.) to 320 mm. long, about 60 mm. to 120 mm. 
wide and has rounded ends. The sanitary napkin 15 is relatively thin and 
has a caliper or thickness of less than about 5 millimeters, more 
desirably less than about 4 millimeters, and most desirably less than 
about 3 millimeters. The sanitary napkin 15 has a body-facing side 16, a 
garment-facing side 17, a substantially liquid-impermeable backing sheet 
or baffle 18, a substantially nonabsorbent, resilient layer 19 and an 
absorbent means 20. 
The resilient layer 19 is made of one or more layers of a flexible, closed 
cell, polyethylene foam material. An example of a foam used in this 
embodiment may be purchased from Sealed Air Corporation, 7110 Sante Fe 
Drive, Hodgkins, Ill. 60525 U.S.A. The grade specification is:"CELL-AIRE" 
Foam, CA-30, thickness of 1/32 inch, density of 1.2 pounds per cubic foot, 
width of 60 inches, on rolls having a linear length of 2000 feet. Ametek 
Microfoam Division, Brandwine Four Building, Routes 1 and 202, Chadds 
Ford, Pa. 19317 U.S.A., produces a light weight polypropylene foam that is 
also suitable for this embodiment. The foam is called "MICROFOAM". 
The resilient layer 19 is located adjacent to and on the body-facing side 
of the baffle 18. The absorbent means 20 is located on the opposite side 
of the resilient layer 19 from the baffle 18. The absorbent means 20 is 
substantially aligned along the central longitudinal axis Y--Y of the 
sanitary napkin 15. The resilient layer 19 has a width greater than the 
width of the absorbent means 20. The resilient layer 19 has a length equal 
to, and desirably greater than, the absorbent means 20. The resilient 
layer 19 has a length of at least 60% of the length of the napkin 15. 
The baffle 18 is designed to face the inner surface, generally the crotch 
portion, of an undergarment (not shown). The baffle 18 blocks the passage 
of body fluids and other liquids. The baffle 18 can be made from 
micro-embossed polymeric films such as polyethylene or polypropylene, or 
it can be made from bicomponent films. A preferred material is 
polyethylene film. 
The absorbent means 20 has an overall length that extends at least about 
50%, and desirably at least about 75%, of the length of the napkin 15. The 
absorbent means 20 has a width of less than about 2.5 inches (63.5 mm.), 
desirably less than about 2 inches (50.8 mm.), more desirably between 
about 0.5 and 2.0 inches (12.7 mm. and 50.8 mm.), and most desirably about 
1.25 inches (31.8 mm.) or 1.50 inches (38.1 mm.) when measured across the 
central transverse axis Y--Y of the napkin 15. Desirably, the absorbent 
means 20 has a width which is less than about 60% of the total width of 
the body-facing side of the sanitary napkin 15 when measured across the 
narrowest portion of the napkin 15. The total width of the sanitary napkin 
15 is measured along an axis, such as axis X--X in FIG. 1, transverse to 
the longitudinal axis Y--Y of sanitary napkin 15. The total width of the 
sanitary napkin 15 is the distance from one outer side edge 21 to the 
opposite outer side edge 23 of the body-facing side of the napkin. 
Desirably, the width of the napkin spans the width of the labia majora of 
the user. The absorbent means 20 has sufficient stiffness to enable the 
sanitary napkin 15 to resist twisting and "roping", as a result of its 
stiffness. The absorbent means 20 does not extend the full width of the 
sanitary napkin 15 in order to enhance comfort to the wearer. Arranging 
the absorbent means 20 substantially in the center, that is, in 
substantial alignment with the central longitudinal axis Y--Y of the 
sanitary napkin 15, provides the advantage of placing the absorbent means 
20 close to the source of fluid. 
The resilient layer 19 has sufficient resilience to resist bunching of the 
sanitary napkin 15. The combination of the resilient layer 19 and the 
absorbent means 20 resists both twisting and bunching. The resilient layer 
19 is not as stiff as the absorbent means 20 and, for that reason, is 
arranged to be wider than the absorbent means 20. Desirably the width of 
the resilient layer 19 is in the range of 60% to 100% of the total width 
of the sanitary napkin 15. 
The absorbent means 20 constitutes the significant absorbing portion of the 
napkin 15 and has the capability of absorbing at least about 80%, 
desirably about 90%, and most desirably about 95% of the body fluid 
deposited on the napkin 15. In terms of amount of body fluid, the 
absorbent means 20 can absorb at least 10 grams, desirably about 20 grams, 
and most desirably, about 30 grams or more of body fluid. Thus, the 
absorbent means 20 is both the primary absorbent and a stiffening means. 
On the body-facing side 16 of the sanitary napkin 15, there is a cover 
layer 22 on the outside of the sanitary napkin 15. Inside the cover layer 
22 and adjacent to it, there is a transfer layer 24. There is construction 
adhesive 26 between the transfer layer 24 and the cover layer 22. In FIGS. 
2 and 3, the construction adhesive 26 is represented by a series of dots 
in various locations and between various layers or components in the 
sanitary napkin 15. 
The cover layer 22 is liquid-permeable and is designed to contact the body 
of the wearer. It can be constructed of a woven or non-woven, natural or 
synthetic material which is easily penetrated by body fluid. Suitable 
materials include bonded carded webs of polyester, polypropylene, nylon, 
or other heat-bondable fibers. Other polyolefins such as copolymers of 
polypropylene and polyethylene, linear low-density polyethylene, 
finely-perforated film webs and net material also work well. A preferred 
material is a spunbonded polypropylene, non-apertured web which contains 
about 1 to 6% titanium dioxide pigment to give it a clean white 
appearance. A white uniform spunbonded material is desirable because the 
color exhibits good masking properties to hide menses which has passed 
through it and the material has sufficient strength to resist being torn. 
U.S. Pat. Nos. 4,801,494 issued to Datta et al. and 4,908,026 issued to 
Sukiennik et al. describe various cover materials which can be used with 
the sanitary napkin 15. The description in the two patents is incorporated 
herein by reference and made a part hereof. 
The liquid-permeable cover layer 22 can also contain a plurality of 
apertures formed therein and the apertures can be arranged along the 
longitudinal center line Y--Y, if desired. The apertures will increase the 
rate at which body fluids can penetrate down into the absorbent means 20. 
The cover layer 22 may also be treated with a surfactant to make it more 
hydrophilic. The surfactant may include topical additions or internally 
applied materials such as polysiloxanes. 
The transfer layer 24 is made of an absorbent nonwoven polypropylene 
meltblown web which facilitates movement of body fluid downward and 
outward from the cover 22 to distant areas of the central absorbent means 
20. In the alternative, the transfer layer 24 may be made of an absorbent 
nonwoven polypropylene spunbond web or other material having similar 
properties. Desirably, the transfer layer 24 is aligned along the central 
longitudinal axis Y--Y of the sanitary napkin 15 and is sized and 
configured to correspond to the shape and dimensions of the central 
absorbent means 20. Desirably also, the transfer layer 24 is slightly 
longer than the absorbent means 20. A description of a transfer layer is 
taught in U.S. Pat. No. 4,798,603 issued to Meyer et al. and assigned to 
the present assignee. This patent is incorporated by reference and made a 
part hereof. 
The transfer layer 24 has a width approximately equal to the absorbent 
means 20. The cover layer 22 has a width approximately equal to the width 
of the sanitary napkin 15 and the cover layer 22 extends out to the 
periphery of the sanitary napkin 15. A first tissue layer 28 is located 
between the transfer layer 24 and the absorbent means 20. The first tissue 
layer 28 has a width greater than the width of the transfer layer 24 and 
greater than the width of the absorbent means 20. During use, menses or 
other body fluid first contacts the cover layer 22, then reaches the 
transfer layer 24, then reaches the first tissue layer 28 and then reaches 
the absorbent means 20. 
The body-facing side of the transfer layer 24 has adhesive 26 over 
substantially the entire surface of the body-facing side of the transfer 
layer 24. The garment-facing side of the transfer layer 24 does not have 
adhesive over the entire surface of the garment-facing side. Instead, the 
garment-facing side of the transfer layer 24 has a single line of adhesive 
26 in the middle of the transfer layer 24, between the transfer layer 24 
and the first tissue layer 28. 
The cover layer 22 has a body-facing side and a garment-facing side. The 
garment-facing side of the cover layer 22 has adhesive over its entire 
surface. As a result, there is adhesive 26 between the transfer layer 24 
and the cover layer 22. In addition, there is adhesive 26 between the 
cover layer 22 and the first tissue layer 28. There is no adhesive between 
the first tissue layer 28 and the absorbent means 20. 
The absorbent means 20 has a body-facing side and a garment-facing side. On 
the garment-facing side of the absorbent means 20, and between it and the 
resilient layer 19, there is a second tissue layer 30. The second tissue 
layer 30 has a width approximately equal to the width of the first tissue 
layer 28. Both tissue layers have a width which is greater than the width 
of the absorbent means 20 and, desirably, greater than two times the width 
of the absorbent means 20. There is adhesive 26 between the garment-facing 
side of the absorbent means 20 and the second tissue layer 30. 
The second tissue layer 30 has a body-facing side and a garment-facing 
side. The garment-facing side of the second tissue layer 30 is adjacent to 
the resilient layer 19. Between the second tissue layer 30 and the 
resilient layer 19 there is adhesive 26 which extends over a portion of 
the garment-facing side of the second tissue layer 30 and a portion of the 
body-facing side of the resilient layer 19. The area over which there is 
adhesive 26 between the second tissue layer 30 and the resilient layer 19 
is an area slightly less than the area of the garment-facing side of the 
absorbent means 20. 
There is adhesive between the body-facing side of the second tissue layer 
30 and the absorbent means 20. At the ends of the sanitary napkin 15, 
there is adhesive between the first tissue layer 28 and the second tissue 
layer 30. The resilient layer 19 has a body-facing side and a 
garment-facing side. The baffle 18 is located on the garment-facing side 
of the resilient layer 19. There is adhesive 26 between the resilient 
layer 19 and the baffle 18. 
If the resilient layer 19 is too thick or too stiff, or both, such 
thickness or stiffness may interfere with comfort to the wearer. It has 
been found that a thin resilient layer 19 is effective if it is adhered or 
bonded to the baffle 18. Such a resilient layer 19 bonded to the baffle 18 
achieves the desired stiffness and thus the desired resistance to bunching 
and yet allows a thinner resilient layer 19 to be used than if the 
resilient layer 19 were not bonded to the baffle 18. The thinner resilient 
layer 19 bonded to the baffle 18 provides more comfort to the user than a 
thicker resilient layer 19. Bonding the film baffle 18 to the resilient 
layer 19 of foam also facilitates use of a garment adhesive. It is easier 
to use a garment adhesive on a film baffle 18 than placing the garment 
adhesive on a resilient layer 19 made of foam. 
Thus, bonding the foam layer to the film baffle 18 enhances comfort, 
achieves a thinner product and is more economical than a thicker layer of 
foam. It is desirable to use a layer of foam that is 1/8 inch (3.175 mm.) 
thick or less. More desirably, one should use a layer of foam that is 1/16 
inch (1.587 mm.) in thickness or less. Even more desirably, one should use 
a layer of film that is 1/32 inch (0.793 mm.) in thickness. 
Referring to FIG. 1, the first tissue layer 28 and the second tissue layer 
30 have an hourglass shape. As a result, the width of the first tissue 
layer 28 and the second tissue layer 30 is slightly greater at each end of 
the first tissue layer 28 and the second tissue layer 30. As a result, the 
width of the first tissue layer 28 and the second tissue layer 30, 
measured along the axis X--X, is less than the width at the outer ends of 
the first tissue layer 28 and the second tissue layer 30. 
The cover layer 22 and the baffle 18 extend to the outer periphery of the 
sanitary napkin 15. At their outer periphery all around the sanitary 
napkin 15, the cover layer 22 and the baffle 18 are joined together by 
adhesive. At the sides of the napkin 15, the resilient layer 19 extends 
close to the outer periphery of the sanitary napkin 15, but within the 
periphery of the sanitary napkin 15. As a result, the width of the 
resilient layer 19 is slightly less than the width of the cover layer 22 
and the baffle 18. At the ends of the napkin 15, the resilient layer 19 
desirably extends to the outer edge of the napkin 15. As a result, at the 
ends of the napkin 15, the length of the resilient layer 19 is equal to 
the length of the cover layer 22 and the baffle 18. The first tissue layer 
28 and the second tissue layer 30 have a size which is slightly less than 
the size of the resilient layer 19, both in length and in width. 
Referring to FIG. 2, the absorbent means 20 is constructed as a laminate 
comprised of a hydrocolloidal material 32 positioned within a carrier 
layer 34 that is a folded hydrophilic material such as an airlaid tissue. 
The hydrocolloidal material 32, commonly referred to as a superabsorbent, 
can be a hydrogel-forming polymer composition which is water-insoluble, 
slightly cross-linked, and partially neutralized. It can be prepared from 
an unsaturated polymerizable, acid group-containing monomers and 
cross-linked agents. Such superabsorbents are taught in U.S. Pat. Nos. 
4,798,603 issued to Meyers et al., Re. 32,649 issued to Brandt et al. and 
4,467,012 issued to Petersen et al., as well as in published European 
Patent Application 0 339 461 to Kellenberger. These U.S. Patents and the 
European Patent Application are incorporated herein by reference and made 
a part hereof. 
Superabsorbents are very good at retaining body fluids. They have the 
ability to absorb a great amount of fluid in relation to their own weight. 
Typical superabsorbents used in sanitary napkins can absorb anywhere from 
5 to 60 times their weight in blood. However, the absorption mechanism is 
not a rapid absorption and is usually slower than the rate of fluid 
absorption by the cellulose fluff material. The placement of the 
superabsorbent material in the center or lower portion of the napkin 
provides additional time for the superabsorbent to absorb the fluid from 
the transfer layer 24. 
It has been found that superabsorbents having a high mechanical stability 
in the swollen state, an ability to rapidly absorb fluid, and ones having 
a strong liquid binding capacity perform well in catamenial devices. 
Hydroxyfunctional polymers have been found to be good superabsorbents for 
this application. A hydrogel-forming polymer, specifically a partially 
neutralized cross-linked copolymer of polyacrylic acid and polyvinyl 
alcohol is desirable. Such superabsorbents can be obtained from Dow 
Chemical, Hoechst-Celanese, and Stockhausen, Inc., among others. The 
superabsorbent is a partially neutralized salt of cross-linked copolymer 
of polyacrylic acid and polyvinyl alcohol having an absorbency under load 
value about 25. 
The superabsorbent should have a high absorbency under load, that is, it 
should have the ability to expand or swell under a restraining pressure, 
typically about 0.3 pound per square inch (psi). The absorbency under load 
value is a function of gel strength, osmotic pressure within the gel and 
the composition of the polymer itself. The absorbency under load value 
also pertains to the ability of the gel to swell against other 
superabsorbent particles as well as against adjacent fibers when under 
pressure. For purposes of this invention, a superabsorbent having a high 
absorbency under load is defined as having a value of 20 or higher. A 
desirable absorbency under load value is 25 or higher. The test for 
determining an absorbency under load value is taught on page 7, lines 
14-52 of published European Patent Application 0 339 461 (Kellenberger) 
and assigned to the present assignee. In the alternative, the absorbent 
means 20 may be a composite comprised of a hydrophilic material and a 
hydrocolloidal material. The hydrophilic material can be various natural 
or synthetic fibers, including cellulose fibers, surfactant-treated 
meltblown fibers, wood pulp fibers, regenerated cellulose or cotton 
fibers, or a blend of pulp and other fibers. 
The baffle 18 has a body-facing side and a garment-facing side. The 
sanitary napkin 15 also contains two longitudinally-extending strips of 
garment adhesive 36 and 38 which are attached to the exterior surface, 
that is, the garment-facing side, of the baffle 18. The garment adhesive 
is commercially available from National Starch and Chemical Company, 
located at 10 Finderne Ave., Bridgewater, N.J. 08807 U.S.A. The strips of 
garment adhesive 36 and 38 are used to secure the sanitary napkin 15 to 
the inside of the crotch portion of an undergarment so that it can be 
properly aligned with the vaginal opening. A peel strip 39 is releasably 
attached to the garment adhesive strips 36 and 38 and prevents the 
adhesive from becoming contaminated prior to attachment to the 
undergarment. The peel strip 39 can be a white Kraft paper coated on one 
side so that it can be released from a hot melt adhesive. The peel strip 
39 is designed to be removed by the ultimate consumer just prior to 
placement of the sanitary napkin 15 in the undergarment. 
Second Embodiment 
Referring to FIG. 4, a second embodiment of the invention is a sanitary 
napkin 40 that has two tabs 42 and 44, one tab arranged on each side of a 
sanitary napkin 40. In other respects, the sanitary napkin 40 is similar 
to the sanitary napkin 15 illustrated in FIGS. 1, 2 and 3. The tabs 42 and 
44 are intended to be folded around the undergarment of the user and to 
increase the attachment of the sanitary napkin 40 to the garment. 
Third Embodiment 
Referring to FIGS. 5, 6, and 7, a third embodiment of the sanitary napkin 
50 is also about 150 mm. to 320 mm. long, about 60 mm. to 120 mm. wide. 
The sanitary napkin 50 is relatively thin and has a caliper or thickness 
of less than about 5 millimeters, more desirably less than about 4 
millimeters, and most desirably less than about 3 millimeters. The 
sanitary napkin 50 has a body-facing side 52, a garment-facing side 54, a 
substantially liquid-impermeable backing sheet or baffle 56, a 
substantially nonabsorbent, resilient layer 58 and an absorbent means 60. 
The resilient layer 58 is made of a flexible, closed cell polyethylene foam 
material. It is the same type of foam material as used in the first 
embodiment and is available from the same sources as identified for the 
first embodiment. The resilient layer 58 is located adjacent to the baffle 
56. The absorbent means 60 is located on the opposite side of the 
resilient layer 58 from the baffle 56. The absorbent means 60 is 
substantially aligned along the central longitudinal axis Y--Y of the 
sanitary napkin 50. The resilient layer 58 has a width greater than the 
width of the absorbent means 60. The resilient layer 58 has a length equal 
to, and desirably greater than, the absorbent means 60. The resilient 
layer 58 has a length of at least 60% of the length of the napkin 50. 
The baffle 56 is designed to face the inner surface, generally the crotch 
portion, of an undergarment (not shown). The baffle 56 permits the passage 
of air or vapor out of the sanitary napkin 50 while blocking the passage 
of body fluids and liquids. The baffle 18 can be made from micro-embossed 
polymeric films such as polyethylene or polypropylene, or it can be made 
from bicomponent films. A preferred material is polyethylene film. 
The absorbent means 60 has an overall length which extends at least about 
50%, and desirably at least about 75%, of the length of the napkin 15. The 
absorbent means 60 has a width of less than about 2.5 inches (63.5 mm.), 
desirably less than about 2 inches (50.8 mm.), more desirably between 
about 0.5 and 2.0 inches (12.7 mm. and 50.8 mm.), and most desirably about 
1.25 inches (31.8 mm.) or 1.50 inches (38.1 mm.) when measured across the 
central transverse axis Y--Y of the napkin 50. Desirably, the absorbent 
means 60 has a width which is less than about 60% of the total width of 
the body-facing side of the sanitary napkin 50 when measured across the 
narrowest portion of the napkin 50. The total width of the sanitary napkin 
50 is measured along an axis, such as axis X--X in FIG. 5, transverse to 
the longitudinal axis Y--Y of sanitary napkin 50. The total width of the 
sanitary napkin is the distance from one outer side edge 61 to the 
opposite outer side edge 63 of the body-facing side of the napkin. 
Desirably, the width of the napkin spans the width of the labia majora of 
the user. Arranging the absorbent means 60 substantially in the center, 
that is, in substantial alignment with the central longitudinal axis Y--Y 
of the sanitary napkin 50, provides the advantage of placing the absorbent 
means 60 close to the source of fluid. 
The absorbent means 60 has sufficient stiffness to enable the sanitary 
napkin 50 to resist twisting and "roping", as a result of its stiffness. 
The absorbent means 60 does not extend the full width of the sanitary 
napkin 50 in order to enhance comfort to the wearer. The resilient layer 
58 has sufficient resilience to resist bunching of the sanitary napkin 50. 
The combination of the resilient layer 58 and the absorbent means 60 
resists both twisting and bunching. The resilient layer 58 is not as stiff 
as the absorbent means 60 and, for that reason, is arranged to be wider 
than the absorbent means 60. Desirably the width of the resilient layer 58 
is in the range of 60% to 100% of the total width of the sanitary napkin 
50. 
The absorbent means 60 constitutes the significant absorbing portion of the 
napkin 50 and has the capability of absorbing at least about 80%, 
preferably about 90%, and most preferably about 95% of the body fluid 
deposited on the napkin 50. In terms of amount of body fluid, the 
absorbent means 60 can absorb at least 10 grams, desirably about 20 grams, 
and most desirably, about 30 grams or more of body fluid. Thus, the 
absorbent means 60 is both the primary absorbent and a stiffening means. 
On the body-facing side 52 of the sanitary napkin 50, there is a 
bicomponent cover 62 on the outside of the sanitary napkin 50. Under the 
cover 62 and adjacent to the cover 62, there is a transfer layer 66. There 
is no construction adhesive between the transfer layer 66 and the cover 
62. In FIGS. 6 and 7, the construction adhesive 65 is represented by a 
series of dots in various locations and between various layers or 
components in the sanitary napkin 50. 
The bicomponent cover 62 is similar to a bicomponent cover described in 
U.S. patent application Ser. No. 731,583, now U.S. Pat. No. 5,415,640 
filed in the name of Robert E. Kirby et al., entitled "A Bodyside Cover 
for an Absorbent Article" and assigned to the same assignee as this Patent 
Application. The bicomponent cover 62 is constructed of two different and 
distinct materials. The first material 67 of the cover 62 desirably 
contains a plurality of apertures formed therethrough, while the second 
material 69 of the cover 62 is desirably nonapertured. The first material 
67 is positioned along the central longitudinal axis Y--Y of the sanitary 
napkin 50 and constitutes the primary fluid-receiving region of the 
bicomponent cover 62. The sanitary napkin 50 is positioned such that 
discharge of body fluid from the vaginal orifice is in direct alignment 
with the upper surface of the first material 67. 
In FIG. 6, the second material 69 overlaps a portion of the longitudinal 
side edges of the first material 67 and is bonded along the side edges by 
a line of adhesive 65. The second material 69 can be bonded to the first 
material 67 by a mechanical attachment, an adhesive, an ultrasonic bond, a 
thermal bond, a pressure bond or a combination of both heat and pressure. 
Other means of attaching the two materials together can also be used. It 
should be noted that the first material 67 can be bonded to the second 
material 69 before the apertures are formed in the first material 67 or 
vice versa. The bicomponent cover 62 can be constructed off-line and then 
assembled into the sanitary napkin 50, or it can be constructed in-line. 
The second material 69 is secured to the first material 67 and forms a 
secondary fluid-receiving region of the bicomponent cover 62. The second 
material 69 is spaced farther away from the point of discharge of body 
fluid than the first material 67. It should be noted that, even though the 
second material 69 is designated as the secondary fluid-receiving region 
of the bicomponent cover 62, it still has the ability to allow fluid to 
pass down through it. The absorbency rate of the second material 69, which 
is defined as the amount of time it takes for a material to absorb a 
certain quantity of fluid, is about equal to or less than the absorbency 
rate through the first material 67. Accordingly, most of the body fluid, 
under normal conditions, is designed to pass through the first material 
67. 
The liquid-permeable cover 62 can also contain a plurality of apertures 
formed therein and the apertures can be arranged along the longitudinal 
center line Y--Y, if desired. The apertures will increase the rate at 
which body fluids can penetrate down into the absorbent means 60. The 
cover 62 can also be treated with a surfactant to make it more 
hydrophilic. The surfactant can include topical additions or internally 
applied materials like polysiloxanes. 
The transfer layer 66 is made of an absorbent nonwoven polypropylene 
spunbond material. In the alternative, the transfer layer 66 may be made 
of an absorbent nonwoven polypropylene meltblown material, a bonded carded 
web, or other material having similar properties. Desirably, the transfer 
layer 66 is aligned along the central longitudinal axis of the sanitary 
napkin 50 and is sized and configured to correspond to the shape and 
dimensions of the central absorbent means 60. Desirably also, the transfer 
layer 66 is slightly longer than the absorbent means 60. A description of 
a transfer layer 66 is taught in U.S. Pat. No. 4,798,603 issued to Meyer 
et al. and assigned to the present assignee. This patent is incorporated 
by reference and made a part hereof. Under the transfer layer 66 is the 
absorbent means 60. The transfer layer 66 has a width approximately equal 
to the absorbent means 60. The bicomponent cover layer 62 has a width 
approximately equal to the width of the sanitary napkin 50 and the cover 
layer 62 extends out to the periphery of the sanitary napkin 50. 
There is a tissue layer 68 that has two plies and is located between the 
resilient layer 58 and the absorbent means 60. The tissue layer 68 has a 
width greater than the absorbent means 60. As a result, the tissue layer 
68 extends between the cover layer 62 and the resilient layer 58. During 
use, menses or other body fluid first contacts the first material 67 of 
the cover 62, then reaches the transfer layer 66, and then reaches the 
absorbent means 60. The body-facing side of the transfer layer 66 has no 
adhesive. The garment-facing side of the transfer layer 66 does have 
adhesive at each end. But, there is no adhesive between the garment-facing 
side of the transfer layer 66 and the body-facing side of the absorbent 
means 60. The absorbent means 60 has a body-facing side and a 
garment-facing side. There is also adhesive 65 on the garment-facing side 
of the absorbent means 60 between the tissue layer 68 and the absorbent 
means 60. There is also adhesive 65 between the two plies of the tissue 
layer 68. 
The resilient layer 58 has a body-facing side and a garment-facing side. 
The baffle 56 is located on the garment-facing side of the resilient layer 
58. There is adhesive between the resilient layer 58 and the baffle 56. 
If the resilient layer 58 is too thick, the thickness interferes with 
comfort of the wearer. It has been found that a thin resilient layer 58 is 
effective if it is adhered or bonded to the baffle 56. Such a resilient 
layer 58 bonded to the baffle 56 achieves the desired resistance to 
bunching and yet allows a thinner resilient layer 58 to be used than if 
the resilient layer 58 were not bonded to the baffle 56. The thinner 
resilient layer 58 bonded to the baffle 56 provides more comfort to the 
user than a thicker resilient layer 58. Bonding the film baffle 56 to the 
resilient layer 58 of foam also facilitates use of a garment adhesive. It 
is easier and seems to work better to use a garment adhesive on a film 
baffle 56 than placing the garment adhesive on a resilient layer 58 made 
of foam. 
Thus, bonding the foam layer to the film baffle 56 enhances comfort, 
achieves a thinner product and is more economical than a thicker layer of 
foam. It is desirable to use a layer of foam that is 1/8 inch thick or 
less. More desirably, one should use a layer of foam that is 1/16 inch in 
thickness or less. Even more desirably, one should use a layer of film 
that is 1/32 inch or less. 
The cover 62 and the baffle 56 extend to the outer periphery of the 
sanitary napkin 50. At their outer periphery, the cover 62 and the baffle 
56 are joined together by adhesive. Desirably, the resilient layer 58 
extends in both length and width close to the outer periphery of the 
sanitary napkin 50, but within the periphery of the sanitary napkin 50. As 
a result, the size of the resilient layer 58 is slightly less than the 
size of the cover 62 and the baffle 56, both in width and in length. The 
two ply tissue layer 68 has a size approximately equal to the size of the 
resilient layer 58, both in length and in width. 
Referring to FIG. 6, the absorbent means 60 is constructed as a laminate 
comprised of a hydrocolloidal material positioned within a folded 
hydrophilic material such as an airlaid tissue, the same as described for 
sanitary napkin 15, the first embodiment. 
The first material 67 of the bicomponent cover 62 may be a thermoplastic 
film, an extrusion-coated nonwoven, or a net material that has openings 
between the strands or threads due because of its construction. Useful 
thermoplastic films include polyolefin materials, such as polyethylene, 
which can be manufactured in various forms. Such films and film making 
processes are commercially available from the following companies: 
Smith & Nephew Plastic, Ltd. Gilberdyke, Brough North Humderside HU 15 2TD 
United Kingdom 
Applied Extrusion Technologies, Inc. P.O. Box 582 Middleton, Del. 19709 
Fameccanica Fraz Sambuceto I-66020 San Giovanni Teatino Italy 
LCL Manufacturing PTE Ltd. 16 Pandan Rd. Singapore 2260 
The first material 67 can also be a net, an embossed net, an extruded 
netting or a net formed from strands of filaments or threads. Examples of 
covers constructed of netting are taught in U.S. Pat. Nos.: 2,295,439; 
2,564,689; 2,900,980; and 4,741,941. These patents are incorporated by 
reference and made a part hereof. The open spaces between the filaments or 
threads of the netting serve the same function as the apertures or 
perforations formed through a thermoplastic film. The first material 67 
can also be a foam material having a plurality of apertures formed 
therethrough. 
An extrusion-coated nonwoven includes a laminate film composite and 
normally refers to a class of composite materials wherein a lower 
substrate ply is either mechanically, thermally or chemically adhered to 
an upper film based ply. The substrate may consist of any nonwoven 
including bonded carded webs, spunbond webs, meltblown webs or 
cellulose-based tissues. The upper film ply can be an apertured plastic 
film, a cast continuous film which would be apertured prior to application 
to the substrate or be a net material. 
The first material 67 has a thickness of less than about 2 millimeters and 
desirably in the range of from about 0.05 to about 2.0 millimeters. The 
first material 67 can have a three-dimensional profile to give it extra 
thickness and enhance its functionality. One way to acquire a 
three-dimensional profile is to emboss the material between the nip of a 
pair of rollers. 
The apertures formed in the first material 67 can vary in size, shape and 
pattern. The apertures can be arranged in either a systematic, uniform or 
random pattern. A systematic pattern, with similarly sized apertures, is 
desirable. The apertures can be formed by mechanically perforating the 
material, such as by needling or punching, be formed by hot vacuum 
drawing, or be formed by other methods known to those skilled in the art. 
The apertures should be formed through the entire thickness of the first 
material 67. It should be noted that the geometrical shape of the 
sidewalls of each aperture can vary. For example, the apertures can be 
round, triangular, square, or irregular in cross-sectional shape. The 
sidewalls of the apertures can be aligned perpendicularly to the top plane 
of the first material 67 or they can be slanted at a desired angle. 
When forming the apertures in the first material 67, it is possible to form 
the apertures such that the apex of each extends below the base plane of 
the first material 67. This configuration will allow the sidewalls of each 
aperture to contact and penetrate the fibers of an adjacent layer, for 
example, a cellulose pulp layer or a separation layer. This can be 
advantageous in providing rapid transfer of body fluid down, into the 
absorbent or into a separation layer. 
In FIG. 6, the first material 67 is shown forming a smaller portion of the 
exposed surface area of the bicomponent cover layer 62 than the second 
material 69. The reason for this is that, when the first material 67 is a 
thermoplastic film and the second material 69 is a nonwoven web, the film 
is more expensive than the nonwoven web, and therefore it is beneficial to 
use less of it. Even though the second material 69 occupies a larger 
portion of the exposed surface area of the bicomponent cover layer 62 than 
the first material 67, it is possible to have the first material 67 form 
an equal or larger portion of the bicomponent cover 62, if desired. 
The second material 69 of the bicomponent cover layer 62 is preferably a 
liquid-permeable nonwoven web. The nonwoven web can be a fibrous material 
formed from fusible polymeric fibers or filaments. The nonwoven web is 
nonperforated, although a perforated web can be used if desired. The 
nonwoven web can be formed from any of the following polymers: polyamides, 
polyesters, polyolefins, polyvinyl acetate, polyvinyl chloride, polyvinyl 
alcohol, cellulose acetate, viscose, and the like. Suitable materials 
include polypropylene spunbond and bonded carded webs. An appropriate 
nonwoven web material should have a uniform web with a denier of about 1.5 
or greater. Such a material, commonly referred to as a linear drawn 
spunbond, is described in U.S. Pat. No. 4,340,563 issued to Appel et al. 
and is hereby incorporated by reference and made a part hereof. 
The baffle 56 has a body-facing side and a garment-facing side. The 
sanitary napkin 50 also contains two longitudinally-extending strips of 
garment adhesive 72 and 74 which are attached to the exterior surface, 
that is, the garment-facing side, of the baffle. The garment adhesive is 
commercially available from National Starch and Chemical Company, located 
at 10 Finderne Ave., Bridgewater, N.J. 08807 U.S.A. The strips of garment 
adhesive 72 and 74 are used to secure the sanitary napkin to the inside of 
the crotch portion of an undergarment so that it can be properly aligned 
with the vaginal opening. A peel strip 76 is releasably attached to the 
garment adhesive strips 72 and 74 and prevents the adhesive from becoming 
contaminated prior to attachment to the undergarment. The peel strip 76 
can be a white Kraft paper coated on one side so that it can be released 
from a hot melt adhesive. The peel strip 76 is designed to be removed by 
the ultimate consumer just prior to placement of the sanitary napkin in 
the undergarment. 
Fourth Embodiment 
Referring to FIG. 8, a fourth embodiment of the invention is a sanitary 
napkin 80 that has a first tab 82 and a second tab 84. One tab is arranged 
on each side of the sanitary napkin 80. In other respects, the sanitary 
napkin 80 is similar to the sanitary napkin 50 illustrated in FIGS. 5, 6 
and 7. The tabs 82 and 84 are intended to be folded around the 
undergarment of the user and to increase the attachment of the sanitary 
napkin 80 to the garment. 
Resilient Layer 
In the context of this invention, resilience refers to the ability of a 
material to return or spring back to its original position, an 
approximately flat position, against the panty, after having been bent or 
compressed or both. Bending and compression occur during use, as a result 
of movements of the wearer of the sanitary napkin. This ability of the 
resilient layer is imparted to the sanitary napkin or other absorbent 
article. As a result, the entire sanitary napkin has the ability to return 
to its original position, approximately flat, against the panty. 
For the first, second, third and fourth embodiments, it is desirable to 
select a material for the resilient layer that is substantially 
non-absorbent and substantially non-wicking. Such a material reduces 
wicking or other flow of fluid, especially in a transverse direction 
toward the edge of the sanitary napkin. As a result, such a material 
reduces any tendency to leak at the sides of the napkin and protects the 
undergarment and other garments of the user. The resilient layers 19 and 
58 may be a foam polymer or it may be another material having properties 
similar to foam. The material selected for the resilient layer should be 
one which has desirable resilience properties. The resilience of the 
material should be substantially unaffected by water and body fluids. Many 
materials commonly used in absorbent articles, such as pulp and other 
absorbent materials, do not have sufficient resilience when wet. Wet 
resilience, that is, resilience when wet, and dry resilience, that is, 
resilience when dry, are both important. 
The resilient layers 19 and 58 provide resistance to bunching. The 
resilient layers also contribute to stiffness and resistance to twisting. 
Resistance to bunching is a function of crush resistance force and 
resilient force. Crush resistance is the ability of a material to resist 
an applied force, such as a force that tends to crush or bend the 
material. Resilient force is the force with which the material seeks to 
return to its original position. The resilient ratio is the ratio of the 
resilient force to the crush resistance force. To have adequate resistance 
to bunching, one needs a sufficient resilient force. It is desirable to 
have this sufficient resilient force in a material that does not have too 
high of a crush resistance, to insure comfort. Thus a certain minimum 
resilient ratio is desirable, to be able to deliver a sufficient resilient 
force to resist bunching without having too high of a crush resistance. 
A measure of resilient ratio is rebound resilience, as defined by the 
American Society for Testing Materials (ASTM) of 1916 Race Street, 
Philadelphia, Pa. 19103, U.S.A. This is the ratio between the output and 
input energy of a gravity-activated mass which impacts the test piece. See 
ASTM Publications D 3575-84, D 3574-86, and D 1054-87. All of the 
foregoing ASTM publications are incorporated herein by reference and made 
a part hereof. Desirable materials for use in this invention will have a 
rebound resilience of at least about 25%. 
Crush resistance may be measured by an ASTM Circular Bend Flex Test, as 
described in ASTM publication D 4032-82. For the purpose of this 
invention, the plunger described in ASTM D 4032-82 has been modified to 
have a smaller diameter of 6.25 mm., an end tip radius of 2.97 mm. and a 
needle point extending 0.88 mm. from the end of the tip. The needle has a 
0.33 mm. base diameter and a point having a radius of less than 0.5 mm. 
For materials that have similar resilient ratios, resistance to bunching is 
indicated by this Circular Bend Flex Test. The polyethylene foam material 
that we have called out in the foregoing Detailed Description has a 
resilient ratio of about 50%, as indicated by a literature rebound 
resilience of 50%, listed in Encyclopedia of Polymer Science and 
Engineering, Vol. 3, pp. 6 and 7, John Wiley and Sons publishers, New 
York, N.Y., U.S.A., 1985. For this material, a desirable range of crush 
resistance to provide the desired level of resistance to bunching is 
indicated by a Circular Bend Flex in the range of from about 9 to about 42 
grams, desirably in the range of from about 24 to about 42 grams, more 
desirably about 35 grams. 
A useful class of resilient materials for this invention is foams such as 
cellular plastics. These cellular plastics have an apparent density which 
is substantially lower than that of the base polymer (plastic) which is 
made possible by the presence of numerous cells of gas (air) disposed 
throughout its mass. Foams are two-phase gas-solid systems that have a 
supporting solid lattice of polymer or rubber cell walls that are 
continuous throughout the structure. 
The gas (air) phase in a resilient foam is usually distributed in void 
pockets often called cells. Open cell foams contain interconnected cells 
where the gas (air) can pass from one cell to another. Closed cell foams 
contain cells that are discrete from each other such that the gas phase of 
each is held independently by each cell that are sealed by thin walls of 
polymer. 
The American Society for Testing and Materials (ASTM) classifies foamed 
plastics as either rigid or flexible. A flexible foam which is most 
preferred for this invention is one that does not rupture when a 
20.times.2.5.times.2.5 cm piece is wrapped around a 2.5 cm mandrel at a 
uniform rate of 1 lap/5 seconds at 15-25 degrees Centigrade. Rigid foams 
which are not most preferred for this invention are those that do rupture 
under this test, unless they are modified to make them flexible through 
such means as scoring or embossing. 
Foamed plastics can be prepared by many means. The expansion process is 
that of expanding a fluid polymer phase to a low density cellular state 
and then "freezing" the polymer structure by curing or through cooling of 
the liquid polymer. 
The extrusion process for producing resilient foams uses physical 
stabilization in a decompression expansion process. This process uses a 
blowing agent blended into the molten polymer that is extruded under 
pressure. This solution of polymer and blowing agent is forced out through 
a die opening on to a moving belt at normal room temperature and pressure. 
This reduction in pressure causes the blowing agent to vaporize resulting 
in expansion of the polymer. The polymer is allowed to cool during 
expansion such that enough structural strength is obtained for the 
required density and dimensional stability. Freezing of the structure or 
stabilization of the polymer structure is a result of the polymer phase 
cooling to a point below its glass transition temperature. Cooling comes 
mainly from three areas: (1) the vaporization of the blowing agent, (2) 
gas expansion, and (3) heat loss to the environment. 
Polyolefin foams made with base polymers of polyethylene and polypropylene 
are prepared by both molding and extrusion processes. It is desirable for 
these embodiments to use low density polyethylene foam products which are 
prepared by an extrusion technique using a gaseous blowing agent. Other 
methods of producing cellular plastics include leaching out solid or 
liquid materials that have been dispersed in a polymer, sintering small 
particles, and dispersing small cellular particles in a polymer. 
Other methods of generating the cellular structures are by dispersing gas 
(or solid) in the fluid state and stabilizing this cellular state, or by 
sintering polymer particles in a structure that contains a gas phase. 
Chemical stabilization process is a common used method used to produce 
resilient foams. Condensation polymers are more suitable for foaming by 
this process than for vinyl polymers because of the fast yet controllable 
curing reactions and the absence of atmospheric inhibition. Polyurethane 
based foams are made by this process. This is not the most desirable foam 
for these embodiments due to extractables and long term aging and 
discoloration of polyurethanes foamed products. 
Decompression expansion foam processes are most preferred for making the 
foam used in these embodiments. By using a physical stabilization process, 
cellular polystyrene, cellulose acetate, polyolefins, or poly(vinyl 
chloride) can be manufactured for use in these embodiments. 
Examples of other materials that may be used for the resilient layers 19 
and 58 are: silicone, polyurethane, polypropylene, latex and pulp. If the 
material is not substantially non-absorbent, desirably it should be 
treated to make it substantially non-absorbent. 
Zones of Thickness, Stiffness and Absorbency 
Referring to FIGS. 2 and 6, the sanitary napkins 15 and 50 each have at 
least two zones which extend longitudinally, that is, parallel to 
longitudinal axis Y--Y: a central absorbent zone 102 and 122 and a 
peripheral zone 106 and 126. Desirably, the napkins 15 and 50 also have an 
adjacent zone 104 and 124 between the central absorbent zone and the 
peripheral zone. Desirably, there are two peripheral zones, one on each 
side of the napkins 15 and 50 and two adjacent zones, one on each side of 
the napkin. The central absorbent zones 102 and 122, the adjacent zones 
104 and 124 and the peripheral zones 106 and 126 are all at least 60% of 
the total length of the napkins 15 and 50. 
The sanitary napkins 15 and 50 are thickest, stiffest, and most absorbent 
in their central absorbent zones 102 and 122 where the absorbent means 20 
and 60 are located. They are less thick, less stiff, and less absorbent in 
the adjacent zones 104 and 124 and are least thick, least stiff, and least 
absorbent in the peripheral zones 106 and 126. As a result, the sanitary 
napkins 15 and 50 are thinner in their adjacent zones 104 and 124 and 
peripheral zones 106 and 126 than most sanitary napkins. Also, as a 
result, the sanitary napkins 15 and 50 are softer in their peripheral 
zones 106 and 126 than most sanitary napkins, which enhance comfort. The 
sanitary napkins 15 and 50 have a finished peripheral edge which visually 
communicates to the user that fluid is not likely to reach the edges, 
especially the side edges, because the main absorbent does not extend to 
the side edges. 
The stiffness of the central absorbent zones can be obtained by making the 
central absorbent zone thicker; by constructing it out of several layers, 
by using stiffer materials, by changing the basis weight or by placing 
another layer of material vertically adjacent to it. The central absorbent 
zone has a Gurley stiffness of at least about 500 milligrams, and 
desirably higher. See Tables 1 and 2. 
Referring to FIG. 2, the central absorbent zone in thickness, that is, in 
cross section, includes: the cover layer 22, the transfer layer 4, the 
first tissue layer 28, the absorbent means 20, the second tissue layer 30, 
the resilient layer 19, the baffle 18, the garment adhesive 36, the peel 
strip 39, and construction adhesive 26 between various layers. The 
absorbent means 20 is a component within the central absorbent zone 102. 
The central absorbent zone 102, like the absorbent means 20, has a central 
longitudinal axis that is coincident with the central longitudinal axes 
Y--Y of the sanitary napkin 15. The width of the central absorbent zone 
102 is equal to the width of the absorbent means 20. 
Referring to FIG. 6, the central absorbent zone of sanitary napkin 50 
includes the following layers: the bicomponent cover layer 62, the 
transfer layer 66, the absorbent means 60, the two ply tissue layer 68, 
the resilient layer 58, the baffle 56, the garment adhesive, the peel 
strip, and construction adhesive between the various layers. The absorbent 
means 60 is a component within the central absorbent zone 122. The central 
absorbent zone 122, like the absorbent means 60, has a central 
longitudinal axis that is coincident with the central longitudinal axes 
Y--Y of the sanitary napkin 50. The width of the central absorbent zone is 
equal to the width of the absorbent means. 
Referring to FIG. 2, the adjacent zones 104 include the following layers: 
the cover layer 22, the first tissue layer 28, the second tissue layer 30, 
the resilient layer 19, the baffle 18, the garment adhesive 36, and the 
peel strip 39, and construction adhesive 26 between the various layers. 
The adjacent zone does not include the absorbent means 20 and the transfer 
layer 24. 
Referring to FIG. 6, the adjacent zone 124 likewise includes the following 
layers: the cover layer 62, the two ply tissue layer 68, the resilient 
layer 58, the baffle 56, the garment adhesive, the peel strip, and 
construction adhesive between the various layers. The adjacent zone 124 
does not include the absorbent means 60 and the transfer layer 66. 
Referring to FIG. 2, the peripheral zone 106 includes the following layers: 
the cover layer 22, the baffle 18 and construction adhesive 26 between the 
cover layer 22 and the baffle 18. The peripheral zone 106 may also include 
a small portion of the outer side edge of the resilient layer 19. 
Referring to FIG. 6, the peripheral zone 126 of sanitary napkin 50 includes 
the following layers: cover layer 62, baffle 56 and construction adhesive 
66 between the cover layer 62 and the baffle 56. The peripheral zone 126 
may also include a portion of the outer edge of the tissue layer 68 and 
the resilient layer 58, and adjacent construction adhesive 65. 
Stiffness Testing 
The ability of certain layers of a sanitary napkin to resist an applied 
bending force, known as pad stiffness, is determined by measuring the 
amount of force required to bend a rectangular composite sample cut from 
the sanitary napkin that includes all layers excluding the peel strip. The 
force needed to bend each sample is measured using a Gurley Model 4171-d 
Digital Stiffness Tester which along with weights and precalibration 
strips are available through Teledyne Gurley, Troy, New York, U.S.A. The 
Gurley stiffness test procedure is modeled after the Technical Association 
of the Pulp and Paper Industry (TAPPI) method T 543 pm-84. The Gurley 
Digital Stiffness Tester is an instrument consisting of a balanced vane, 
which is center-pivoted, and to which a variety of weights can be added 
below its pivot point. The vane moves freely to accommodate testing in 
both left and right directions which would be analogous to upward and 
outward body flexing of the samples. 
There is a two part calibration for the Gurley Stiffness Tester. The first 
calibration is done to ensure that the "Vane" pendulum is swinging 
according to specification against a known material (i.e., a brass strip). 
The Gurley instrument is calibrated following the Gurley Digital Stiffness 
Tester Instruction Manual to within 5% variation with a 50.8 mm. wide by 
25.4 mm. long precalibrated Brass Calibration Strip, Gurley part no. 
31644. The second calibration is done to ensure that the internal 
electronic calculations and conversions are accurate. 
The samples cut from each sanitary napkin are 12.7 mm..+-.0.4 mm. wide by 
25.4 min..+-.0.4 mm. long. Each sample overlaps the top of the Gurley vane 
by 6.4 mm. During a test, the sample is moved against the top edge of the 
vane until the sample bends and the vane releases contact with the bottom 
edge of the sample. The point of release is measured by an electronic 
optical encoder which provides a greater degree of accuracy over the 
earlier model Gurley Stiffness Tester as was used in TAPPI T 543 pm-84. 
The electronic optical encoder also displays the result on the digital 
readout. The readout continuously displays readings from tests performed 
in both the left and right directions. The Gurley Model 4171-d also 
computes automatically through an internal microprocessor and displays the 
average of left and right bending stiffness data after each measurement. 
The average reading is then converted by this Gurley instrument into 
milligrams of Gurley stiffness relative to a sample size of 24.5 mm. wide 
by 76.2 mm. long. 
The Gurley Stiffness Tester should be prepared as follows. The required 
weight is attached and the base of the instrument is levelled by adjusting 
the leveling screw until the level's bubble is centered and the pendulum's 
pointer is indicating zero. The switches are set to correspond to the 
weight being used, the weight's position on the pendulum, the width of the 
specimen being tested, and the length of the specimen. For example: if a 
25.4 mm..times.12.7 mm. specimen is tested with the 5 gm weight in the 
25.4 mm. slot, the switches would be set as follows: 
Weight=5 gm 
Weight Position=1 inch 
Width=0.5 inch 
Length=1 inch 
The test procedure to be performed is as follows: 
1. Center the specimen strip over the pendulum such that exactly 6.4 mm. 
(0.25 inches) overlaps the top of the pendulum and exactly 6.4 mm. (0.25 
inches) will be held in the jaws. 
2. Select an appropriate weight and a hole to give a reading between 2 and 
6 on the scale. NOTE: The specimen should be brought to an approximate 
contact with the pendulum vane before applying force to avoid oscillation 
in the early stages. 
3. Press the System Reset button. The display must read 00-000-00. 
4. Press the Motor--Direction switch to cause the clamp arm to press the 
specimen against the pendulum. 
5. Repeat step 4 in the opposite direction to establish both a left scale 
reading, a right scale reading, and an average reading. 
6. Record the average scale reading. 
7. Press the Select Button to attain the milligram calculation and record. 
8. Repeat steps 1 through 7 for each specimen. 
The following procedure was used to obtain samples for Gurley stiffness 
testing. A set of samples was cut from five sanitary napkins of the types 
shown in the Tables. Each sample measured 12.7 mm. by 25.4 mm. Tables 1 
through 16 show comparative data between sanitary napkins of the invention 
described herein and commercially available sanitary napkins which are 
relatively thin in caliper. In the Tables, K-C refers to Kimberly-Clark 
Corporation of Dallas, Tex., U.S.A. Invention A and Invention B refer to 
sanitary napkins 50 of the type described herein as the Third Embodiment. 
Invention H, J, M and W refer to sanitary napkins 15 of the type described 
herein as the First Embodiment. The K-C Ultra Thin Pad with Pulp is 
described in U.S. patent application Ser. No. 556,694, now U.S. Pat. No. 
5,248,309 filed in the name of Serbiak et al. and assigned to 
Kimberly-Clark Corporation. P&G refers to the Procter & Gamble Company of 
Cincinnati, Ohio U.S.A. The K-C Ultra Thin Pad with Pulp and the P&G 
Whisper Excel product with wings, shown in the Tables, are commercially 
available sanitary napkins. The commercially available sanitary napkins 
shown in the Tables do not have the same construction, layers and zones as 
the sanitary napkins 15 and 50 of the present invention. Samples were cut 
from comparable locations in the commercially available napkins as much as 
possible to provide the comparison shown in the Tables. 
FIGS. 9, 10, and 11 show where samples were cut from napkins 50, the Third 
Embodiment. FIG. 12 shows where samples were cut from napkins 15, the 
First Embodiment. FIG. 13 shows the location of certain measurements. The 
longitudinal centerline Y--Y and the transverse centerline X--X of each 
napkin were identified. The peel strip was removed and the garment 
adhesive was dusted with talc or corn starch. Referring to FIG. 9, a 
sample 130 measuring 12.7 mm..times.25.4 mm. was cut in the machine 
direction from each napkin 50 at the intersection of the two centerlines 
Y--Y and X--X. The machine direction referred to in Tables 1, 3, 4, 5, 6, 
7, 8, 9, 10, 11, 12, 13, and 14 corresponds to the longitudinal direction 
of the napkin, i.e. axis Y--Y. The transverse direction referred to in 
Table 2 corresponds to the transverse axis X--X of the napkin 50. Two 
additional samples 132 and 134, each measuring 12.7 mm..times.25.4 mm., 
were cut in the machine direction along the longitudinal centerline. The 
two additional samples 132 and 134 were cut about 63.5 mm. in front of and 
behind the first sample 130. All samples from each napkin were cut and 
handled carefully so as not to affect the sample stiffness. Such samples 
included the central absorbent means 20 plus segments from the other 
layers present at the locations where the samples were taken, that is, 
from the central absorbent zone 122. The Gurley stiffness was measured for 
each sample and the values were recorded in Table 1 as the stiffness of 
the central absorbent zone 122 in the machine direction. 
Referring to FIG. 9, we then identified parallel planes S and T. Planes S 
and T are parallel to the transverse centerline X--X and are 63.5 
millimeters in front of and behind the transverse centerline X--X. Next we 
identified parallel planes P--P and Q--Q. Planes P--P and Q--Q are 
parallel to longitudinal centerline Y--Y and at a distance of (C/4+6.4 
mm.) from centerline Y--Y. C is a measurement of the total width of the 
napkin 50 at its narrowest dimensions between planes S and X and planes T 
and X (shown in FIGS. 11 and 12). We then identified the points of 
intersection for planes P--P, Q--Q, S--S, and T--T. At the intersection of 
planes P--P and S--S, we cut sample 142. At the intersection of planes 
P--P and T--T, we cut sample 144. At the intersection of planes Q--Q and 
T--T, we cut sample 146. At the intersection of planes Q--Q and S--S, we 
cut sample 148. The four samples 142, 144, 146 and 148 each measured 25.4 
millimeters.times.12.7 millimeters. Such samples are in the offset 
adjacent zone 124 and include the resilient layer 58, but not the 
absorbent means 60. Such samples are offset from transverse axis X--X. The 
Gurley stiffness of the samples from the adjacent zone were measured and 
recorded in Table 4 as the stiffness of the offset adjacent zones in the 
machine direction. 
Referring to FIG. 9, we also identified the points of intersection for 
planes P--P, Q--Q, X--X, and Y--Y. At the intersection of planes P--P and 
X--X, we cut sample 160. At the intersection of planes Q--Q and X--X, we 
cut sample 162. The two samples 160 and 162 each measured 25.4 
millimeters.times.12.7 millimeters. Such samples are in the center 
adjacent zones and include the resilient layer 58, but not the absorbent 
means 60. The Gurley stiffness of the samples from the center adjacent 
zones were measured and recorded in Table 3 as the stiffness of the center 
adjacent zone in the machine direction. 
Referring to FIG. 10, from another set of five napkins 50 another sample 
136 measuring 12.7 mm. and 25.4 mm. was cut in the transverse direction 
from each napkin at the intersection of the two centerlines Y--Y and X--X. 
Two additional samples 138 and 140, each measuring 12.7 mm..times.25.4 
mm., were cut in the transverse direction along the longitudinal 
centerline. The two additional samples 138 and 140 were cut about 63.5 mm. 
in front of and behind the first sample. All samples from each napkin were 
cut and handled carefully so as not to affect the sample stiffness. Such 
samples included the central absorbent means 20 plus segments from the 
other layers present at the locations where the samples were taken, that 
is, from the central absorbent zone 122. The Gurley stiffness was measured 
for each sample and the values were recorded in Table 2 as the stiffness 
of the central absorbent zone in the transverse direction. 
Referring to FIG. 10, we also identified parallel planes S and T. Planes S 
and T are parallel to the transverse centerline X--X and are 63.5 
millimeters in front of and behind the transverse centerline X--X. Next we 
identified parallel planes P--P and Q--Q. Planes P--P and Q--Q are 
parallel to longitudinal centerline Y--Y and at a distance of (C/4+6.4 
mm.) from centerline Y--Y. C is a measurement of the total width of the 
napkin 50. We then identified the points of intersection for planes P--P, 
Q--Q, S--S, and T--T. At the intersection of planes P--P and S--S, we cut 
sample 149 in the transverse direction. At the intersection of planes P--P 
and T--T, we cut sample 150 in the transverse direction. At the 
intersection of planes Q--Q and T--T, we cut sample 152 in the transverse 
direction. At the intersection of planes Q--Q and S--S, we cut sample 154 
in the transverse direction. The four samples 149, 150, 152, and 154 each 
measured 25.4 millimeters.times.12.7 millimeters. Such samples are in the 
offset adjacent zone 124 and include the resilient layer 58, but not the 
absorbent means 60. Such samples are offset from transverse axis X--X. The 
Gurley stiffness of the samples from the adjacent zone were measured as 
the stiffness of the offset adjacent zones in the transverse direction. 
Referring to FIG. 10, we also identified the points of intersection for 
planes P--P, Q--Q, X--X, and Y--Y. At the intersection of planes P--P and 
X--X, we cut sample 151 in the transverse direction. At the intersection 
of planes Q--Q and X--X, we cut sample 153 in the transverse direction. 
The two samples 151 and 153 each measured 25.4 millimeters.times.12.7 
millimeters. Such samples are in the center adjacent zones and include the 
resilient layer 58, but not the absorbent means 60. The Gurley stiffness 
of the samples from the center adjacent zones were measured as the 
stiffness of the center adjacent zone in the transverse direction. 
Referring to FIG. 11, four additional points, two on each side of the 
sanitary napkin 50 were identified on the planes S--S and T--T on the 
outer longitudinal sides of the napkin. Samples 174, 176, 178 and 180 were 
cut in the machine direction from each of these points. Such samples did 
not include the central absorbent means 60 and included only a small 
portion of the resilient layer 58 and segments from the other layers 
present where the samples were taken. The Gurley stiffness of each sample 
is measured and recorded in Table 6 as the stiffness of the offset 
peripheral zones of the napkin 50 in the machine direction. The average 
for the stiffness of the offset peripheral zones was calculated and 
recorded as the "average stiffness of the peripheral zones" of the napkin. 
The average stiffness of the offset peripheral zones was then subtracted 
from the average stiffness of the central absorbent zone of the napkin and 
is recorded in Table 8 as the difference in stiffness between the central 
absorbent zone and the offset peripheral zones of the napkins in the 
machine direction. 
Referring to FIG. 11, two additional points, one on each side of the 
transverse centerline X--X, were identified on the outer longitudinal 
sides of the napkin 50. Samples 170 and 172 were cut in the machine 
direction from each of these points. Such samples did not include the 
central absorbent means 20 and included only a small portion of the 
resilient layer 58 and segments from the other layers present where the 
samples were taken. The Gurley stiffness of each sample 170 and 172 was 
measured and recorded in Table 5 as the stiffness of the center peripheral 
zones of the napkin in the machine direction. The average for the 
stiffness of the center peripheral zones was calculated and recorded as 
the "average stiffness of the center peripheral zones" of the napkin. The 
average stiffness of the center peripheral zones was then subtracted from 
the average stiffness of the central absorbent zone of the napkin and is 
recorded in Table 7 as the difference in stiffness between the central 
absorbent zone and the center peripheral zones of the napkin in the 
machine direction. 
The average of the values of the stiffness of the central absorbent zone 
was calculated and recorded as the "average stiffness of the central 
absorbent zone" for the napkin. The average of the values of the stiffness 
of the adjacent zones was calculated and recorded as the "average 
stiffness of the adjacent zones" for the napkin. The "average stiffness of 
the central absorbent zone" was then divided by the "average stiffness of 
the adjacent zones" and is reported as the stiffness ratio of the central 
absorbent zone to the adjacent zone. Referring to FIGS. 12 and 13, 
sanitary napkin 15 has tissue layers 28 and 30 that have an hourglass 
shape 182. Samples were cut from napkins 15 in a manner similar to that 
previously described for FIGS. 9 and 10. Referring to FIG. 13, the width 
of the absorbent zone is A. The width of the tissue layers 28 and 30 along 
the transverse axis X--X is B. Dimension B is the minimum width of the 
tissue layers 28 and 30. The total width of the napkin is C at its 
narrowest dimensions between planes S and X and planes T and X (shown in 
FIGS. 11 and 12). Dimension D is the width of the resilient layer. 
Dimension E is the length of the tissue layers. Dimension F is the length 
of the napkin. 
Table 1 shows the stiffness of samples or segments cut from the central 
absorbent zone in the machine direction for sanitary napkins of the 
present invention and the stiffness of samples from comparable locations 
for other sanitary napkins available commercially. For the present 
invention, the stiffness of the central absorbent zone in the machine 
direction is in the range of from about 477 milligrams (mg.) to about 3067 
mg. Desirably, it is in the range of from about 782 mg. to about 2526 mg. 
Desirably also, it should be above about 477 mg. 
Table 2 shows the stiffness of samples or segments cut from the central 
absorbent zone in the transverse direction for sanitary napkins of the 
present invention and the stiffness of samples from comparable locations 
for sanitary napkins available commercially. For the present invention, 
the stiffness of the central absorbent zone in the transverse direction is 
in the range of from about 342 mg. to about 2445 mg. Desirably, it is in 
the range of from about 494 mg. to about 1647 mg. Desirably also, it 
should be above about 494 mg. 
Table 3 shows the stiffness of samples or segments cut from the center 
adjacent zones in the machine direction for sanitary napkins of the 
present invention and the stiffness of samples from comparable locations 
for other sanitary napkins available commercially. Such samples 160 and 
162 from the center adjacent zones are shown in FIG. 9 at the intersection 
of plane P--P and transverse axis X--X and at the intersection of plane 
Q--Q and transverse axis X--X. For the present invention, the stiffness of 
the center adjacent zones is in the range of from about 99 mg. to about 
345 mg. Desirably, it is in the range of from about 131 mg. to about 297 
mg. 
Table 4 shows the stiffness of samples or segments cut from the offset 
positions in the adjacent zones in the machine direction for sanitary 
napkins of the present invention and the stiffness of samples from 
comparable locations for other sanitary napkins available commercially. 
Such samples are shown in FIG. 9 that is, sample 142 at the intersection 
of plane P--P and S--S; sample 144 at the intersection of plane P--P and 
plane T--T; sample 146 at the intersection of plane Q--Q and plane T--T 
and sample 148 at the intersection of plane Q--Q and S--S. For the present 
invention, the stiffness of the offset adjacent zones is in the range of 
from about 97 mg. to about 411 mg. Desirably, it is in the range of from 
about 121 mg. to about 317 mg. 
Table 5 shows the stiffness of samples cut from the center of the 
peripheral zones in the machine direction, that is, samples 170 and 172 
shown in FIG. 11 along the transverse axis X--X at each side of the napkin 
for sanitary napkins of the present invention and the stiffness of samples 
from comparable locations for other sanitary napkins available 
commercially. For the present invention, the stiffness of the center 
peripheral zones is in the range of from about 28 mg. to about 127 mg. 
Desirably, it is in the range of from about 52 mg. to about 78 mg. 
Table 6 shows the stiffness of samples or segments cut from the peripheral 
zones at their offset positions in the machine direction, that is, samples 
174 and 176 along the plane S--S at each side of the napkin and samples 
178 and 180 along the plane T--T at each side of the napkin. For the 
present invention, the stiffness of the offset peripheral zones is in the 
range of from about 30 mg. to about 115 mg. Desirably, it is in the range 
of from about 70 mg. to about 79 mg. 
Table 7 shows the difference between the average stiffness of the central 
absorbent zone in the machine direction, shown in Table 1, and the average 
stiffness of the adjacent zones in the machine direction from Table 3 for 
center adjacent zones, and from Table 5 for the center peripheral zones 
for sanitary napkins of the present invention and differences in average 
stiffness for comparable locations for other sanitary napkins available 
commercially. "N.D." in the Tables means no data is available. 
Table 8 shows the difference in average stiffness in the machine direction 
between the center adjacent zones shown in Table 3 and the center 
peripheral zones shown in Table 5. The stiffness of the center adjacent 
zones is represented by samples 160 and 162 in FIG. 9. The stiffness of 
the center peripheral zone is represented by samples 170 and 172 in FIG. 
11. 
Table 9 shows the difference in average stiffness in the machine direction 
between the central absorbent zones and offset zones, both the offset 
adjacent zones and the offset peripheral zones. The offset adjacent zones 
are represented by samples 142, 144, 146, and 148 in FIG. 9 and the 
average stiffness is shown in Table 4. The offset peripheral zones are 
represented by samples 174, 176, 178 and 180 in FIG. 11 and the average 
stiffness is shown in Table 6. For the present invention, the difference 
in average stiffness between the central absorbent zone and offset 
adjacent zones is in the range of from about 632 mg. to about 2293 mg. The 
difference in average stiffness between the central absorbent zone and the 
offset peripheral zones is in the range of from about 953 mg. to about 
2456 mg. 
Table 10 shows the difference in average stiffness between the offset 
adjacent zones, that is, represented by samples 142, 144, 146, and 148 in 
FIG. 9 and shown in Table 4; and the offset peripheral zones represented 
by samples 174, 176, 178, and 180 in FIG. 11 and shown in Table 6. For the 
present invention, the difference in average stiffness between the offset 
adjacent zones and the offset peripheral zones is in the range of from 
about 50 mg. to about 162 mg. 
Table 11 shows the ratio of the average stiffness of the central absorbent 
zones, represented by samples 130, 132, and 134 in FIG. 9, to the average 
stiffness of the center adjacent zones, represented by 160 and 162 in FIG. 
9 and shown in Table 3 and to the center peripheral zones, represented by 
samples 170 and 172 in FIG. 11 and shown in Table 5. The ratio of the 
average stiffness of the central absorbent zone to the average stiffness 
of the center adjacent zones is in the range of from about 3.7:1 to about 
10.3:1. The ratio of the average stiffness of the central absorbent zone 
to the average stiffness of the center peripheral zones is in the range of 
from about 14.5:1 to about 32.4:1. 
Table 12 shows the ratio of the average stiffness of the central adjacent 
zones, represented by samples 160 and 162 in FIG. 9 and shown in Table 3, 
to the average stiffness of the center peripheral zones, represented by 
samples 170 and 172, in FIG. 11 and shown in Table 5 
Table 13 shows the ratio of the average stiffness of the central absorbent 
zones to the average stiffness of the offset zones. The central absorbent 
zones are represented by samples 130, 132 and 134 in FIG. 9. The offset 
adjacent zones are represented by samples 142, 144, 146 and 148 in FIG. 9 
and shown in Table 4. The offset peripheral zones are represented by 
samples 174, 176, 178 and 180 in FIG. 11 and shown in Table 6. 
Table 14 shows the ratio of the average stiffness of the offset adjacent 
zones to the average stiffness of the offset peripheral zones in the 
machine direction. The offset adjacent zones are represented by samples 
142, 144, 146 and 148 in FIG. 9 and shown in Table 4. The offset 
peripheral zones are represented by samples 174, 176, 178 and 180 in FIG. 
11 and shown in Table 6. 
Table 15 shows the width of dimensions A, B, C and D in various sanitary 
napkins. For sanitary napkins identified as Invention H and Invention M, 
the width dimensions A, B, C and D are shown in FIG. 13. For sanitary 
napkins identified as Invention A, dimensions B and D are equal because 
there is no hourglass shape for the tissue layers. 
Table 16 shows ratios of certain width dimensions for the dimensions 
provided in Table 15. 
Tables 17, 18 and 19 show the caliper or thickness of sanitary napkins of 
the present invention for the various zones within the sanitary napkin. 
Tables 20 and 21 show the caliper or thickness of commercially available 
sanitary napkins at comparable locations to where the various zones of the 
present invention would be located. Caliper refers to thickness measured 
by a caliper device. The center adjacent zone desirably has a caliper in 
the range of from about 0.5 mm. to about 3.0 mm. More desirably, the 
center adjacent zone has a caliper in the range of about 1.3 mm. to about 
1.5 mm. 
TABLE 1 
______________________________________ 
STIFFNESS OF THE CENTRAL ABSORBENT ZONE 
in Machine Direction 
No. of Gurley Stiffness in milligrams 
Samples 
Average Minimum Maximum 
______________________________________ 
Invention A: K-C 
15 111 522 1532 
Ultra Thin Pad 
with Foam 
Invention B: K-C 
15 2526 2020 3067 
Ultra Thin Pad 
with Foam 
Invention H: K-C 
15 1109 866 1354 
Ultra Thin Pad 
with Foam 
Invention J: K-C 
15 1020 667 1498 
Ultra Thin Pad 
with Foam 
Invention M: K-C 
15 1025 755 1288 
Ultra Thin Pad 
with Foam 
Invention W: K-C 
15 782 477 1143 
Ultra Thin Pad 
with Foam 
K-C Ultra Thin Pad 
15 695 560 905 
with Pulp 
P&G Whisper Excel 
15 214 133 278 
(with wings) 
______________________________________ 
TABLE 2 
______________________________________ 
STIFFNESS OF THE CENTRAL ABSORBENT ZONE 
in Transverse Direction 
No. of Gurley Stiffness in milligrams 
Samples 
Average Minimum Maximum 
______________________________________ 
Invention A: K-C 
15 893 699 1310 
Ultra Thin Pad 
with Foam 
Invention B: K-C 
15 1647 1154 2445 
Ultra Thin Pad 
with Foam 
Invention H: K-C 
15 821 616 1010 
Ultra Thin Pad 
with Foam 
Invention J: K-C 
15 494 297 738 
Ultra Thin Pad 
With Foam 
Invention M: K-C 
15 806 599 977 
Ultra Thin Pad 
with Foam 
Invention W: K-C 
15 512 342 755 
Ultra Thin Pad 
with Foam 
K-C Ultra Thin Pad 
15 392 278 560 
with Pulp 
P&G Whisper Excel 
15 171 104 453 
(with wings) 
______________________________________ 
TABLE 3 
______________________________________ 
STIFFNESS OF CENTER ADJACENT ZONES 
in Machine Direction 
No. of Gurley Stiffness in milligrams 
Samples 
Average Minimum Maximum 
______________________________________ 
Invention A: K-C 
10 211 172 245 
Ultra Thin Pad 
with Foam 
Invention B: K-C 
10 245 195 289 
Ultra Thin Pad 
with Foam 
Invention H: K-C 
10 297 239 345 
Ultra Thin Pad 
with Foam 
Invention J: K-C 
10 133 99 175 
Ultra Thin Pad 
with Foam 
Invention M: K-C 
10 131 108 168 
Ultra Thin Pad 
with Foam 
Invention W: K-C 
10 169 122 278 
Ultra Thin Pad 
with Foam 
K-C Ultra Thin Pad 
10 119 33 267 
with Pulp 
P&G Whisper Excel 
10 178 145 217 
(with wings) 
______________________________________ 
TABLE 4 
______________________________________ 
STIFFNESS OF OFFSET ADJACENT ZONES 
in Machine Direction 
No. of Gurley Stiffness in milligrams 
Samples 
Average Minimum Maximum 
______________________________________ 
Invention A: K-C 
20 198 133 245 
Ultra Thin Pad 
with Foam 
Invention B: K-C 
20 233 181 322 
Ultra Thin Pad 
with Foam 
Invention H: K-C 
20 317 239 411 
Ultra Thin Pad 
with Foam 
Invention J: K-C 
20 198 114 372 
Ultra Thin Pad 
with Foam 
Invention M: K-C 
20 121 97 175 
Ultra Thin Pad 
with Foam 
Invention W: K-C 
20 150 100 225 
Ultra Thin Pad 
with Foam 
K-C Ultra Thin Pad 
20 86 20 200 
With Pulp 
P&G Whisper Excel 
20 167 136 220 
(with wings) 
______________________________________ 
TABLE 5 
______________________________________ 
STIFFNESS OF THE CENTER PERIPHERAL ZONES 
in Machine Direction 
No. of Gurley Stiffness in milligrams 
Samples 
Average Minimum Maximum 
______________________________________ 
Invention A: K-C 
10 77 47 110 
Ultra Thin Pad 
with Foam 
Invention B: K-C 
10 78 44 127 
Ultra Thin Pad 
with Foam 
Invention M: K-C 
10 52 28 82 
Ultra Thin Pad 
with Foam 
K-C Ultra Thin Pad 
10 25 13 43 
with Pulp 
P&G Whisper Excel 
10 7 1 14 
(with wings) 
______________________________________ 
TABLE 6 
______________________________________ 
STIFFNESS OF THE OFFSET PERIPHERAL ZONES 
in Machine Direction 
No. of Gurley Stiffness in milligrams 
Samples 
Average Minimum Maximum 
______________________________________ 
Invention A: K-C 
20 79 54 115 
Ultra Thin Pad 
with Foam 
Invention B: K-C 
20 70 30 109 
Ultra Thin Pad 
with Foam 
Invention M: K-C 
20 72 34 104 
Ultra Thin Pad 
with Foam 
K-C Ultra Thin Pad 
20 35 17 76 
with Pulp 
P&G Whisper Excel 
20 87 20 178 
(with wings) 
______________________________________ 
TABLE 7 
______________________________________ 
DIFFERENCE IN AVERAGE STIFFNESS BETWEEN 
THE CENTRAL ABSORBENT ZONES AND THE 
ADJACENT ZONES in Machine Direction 
Gurley Stiffness 
in milligrams 
Center Center 
Adjacent 
Peripheral 
Zones Zones 
______________________________________ 
Invention A: K-C Ultra 
900 1034 
Thin Pad with Foam 
Invention B: K-C Ultra 
2282 2448 
Thin Pad with Foam 
Invention H: K-C Ultra Thin 
812 N.D. 
Pad with Foam 
Invention J: K-C Ultra Thin 
887 N.D. 
Pad with Foam 
Invention M: K-C Ultra Thin 
894 973 
Pad with Foam 
Invention W: K-C Ultra Thin 
613 N.D. 
Pad with Foam 
K-C Ultra Thin Pad 576 670 
with Pulp 
P&G Whisper Excel 36 207 
(with wings) 
______________________________________ 
TABLE 8 
______________________________________ 
DIFFERENCE IN AVERAGE STIFFNESS BETWEEN 
THE CENTER ADJACENT ZONES AND THE 
CENTER PERIPHERAL ZONES in Machine Direction 
Gurley Stiffness 
in milligrams 
______________________________________ 
Invention A: K-C Ultra 
134 
Thin Pad with 
Invention B: K-C Ultra 
167 
Thin Pad with Foam 
Invention H: K-C Ultra Thin 
N.D. 
Pad with Foam 
Invention J: K-C Ultra Thin 
N.D. 
Pad with Foam 
Invention M: K-C Ultra Thin 
79 
Pad with Foam 
Invention W: K-C Ultra Thin 
N.D. 
Pad with Foam 
K-C Ultra Thin Pad 93 
with Pulp 
P&G Whisper Excel 171 
(with wings) 
______________________________________ 
TABLE 9 
______________________________________ 
DIFFERENCE IN AVERAGE STIFFNESS BETWEEN 
THE CENTRAL ABSORBENT ZONE AND THE OFFSET 
ZONES in Machine Direction 
Gurley Stiffness 
in milligrams 
Offset Offset 
Adjacent 
Peripheral 
Zones Zones 
______________________________________ 
Invention A: K-C Ultra Thin 
913 1032 
Pad with Foam 
Invention B: K-C Ultra Thin 
2293 2456 
Pad with Foam 
Invention H: K-C Ultra Thin 
792 N.D. 
Pad with Foam 
Invention J: K-C Ultra Thin 
822 N.D. 
Pad with Foam 
Invention M: K-C Ultra Thin 
904 953 
Pad with Foam 
Invention W: K-C Ultra Thin 
632 N.D. 
Pad with Foam 
K-C Ultra Thin Pad 610 660 
with Pulp 
P&G Whisper Excel 35 127 
(with wings) 
______________________________________ 
TABLE 10 
______________________________________ 
DIFFERENCE IN AVERAGE STIFFNESS BETWEEN 
THE OFFSET ADJACENT ZONES AND THE 
OFFSET PERIPHERAL ZONES in Machine Direction 
Gurley Stiffness 
in milligrams 
______________________________________ 
Invention A: K-C Ultra Thin 
119 
Pad with Foam 
Invention B: K-C Ultra Thin 
162 
Pad with Foam 
Invention H: K-C Ultra Thin 
N.D. 
Pad with Foam 
Invention J: K-C Ultra Thin 
N.D. 
Pad with Foam 
Invention M: K-C Ultra Thin 
49 
Pad with Foam 
Invention W: K-C Ultra Thin 
N.D. 
Pad with Foam 
K-C Ultra Thin Pad 50 
with Pulp 
P&G Whisper Excel 80 
(with wings) 
______________________________________ 
TABLE 11 
______________________________________ 
RATIO OF THE AVERAGE STIFFNESS OF THE 
CENTRAL ABSORBENT ZONE TO THE AVERAGE 
STIFFNESS OF THE CENTER ADJACENT ZONES 
AND TO THE CENTER PERIPHERAL ZONES 
in Machine Direction 
Center Center 
Adjacent 
Peripheral 
Zones Zones 
______________________________________ 
Invention A: K-C Ultra Thin Pad 
5.3 14.5 
with Foam 
Invention B: K-C Ultra Thin Pad 
10.3 32.4 
with Foam 
Invention H: K-C Ultra Thin Pad 
3.7 N.D. 
with Foam 
Invention J: K-C Ultra Thin Pad 
7.7 N.D. 
with Foam 
Invention M: K-C Ultra Thin Pad 
7.8 19.8 
with Foam 
Invention W: K-C Ultra Thin Pad 
4.6 N.D. 
with Foam 
K-C Ultra Thin Pad with Pulp 
5.9 27.4 
P&G Whisper Excel 1.1 30.1 
(with wings) 
______________________________________ 
TABLE 12 
______________________________________ 
RATIO OF AVERAGE STIFFNESS OF CENTER 
ADJACENT ZONES TO AVERAGE STIFFNESS OF 
CENTER PERIPHERAL ZONES in Machine Direction 
Averages 
______________________________________ 
Invention A: K-C Ultra Thin Pad 
2.8 
with Foam 
Invention B: K-C Ultra Thin Pad 
3.1 
with Foam 
Invention H: K-C Ultra Thin Pad 
N.D. 
with Foam 
Invention J: K-C Ultra Thin Pad 
N.D. 
with Foam 
Invention M: K-C Ultra Thin Pad 
2.5 
with Foam 
Invention W: K-C Ultra Thin Pad 
N.D. 
with Foam 
K-C Ultra Thin Pad with Pulp 
4.7 
P&G Whisper Excel 25.0 
(with wings) 
______________________________________ 
TABLE 13 
______________________________________ 
RATIO OF AVERAGE STIFFNESS OF CENTRAL 
ABSORBENT ZONES TO AVERAGE STIFFNESS OF 
THE OFFSET ZONES in Machine Direction 
Offset Offset 
Adjacent 
Peripheral 
Zones Zones 
______________________________________ 
Invention A: K-C Ultra Thin Pad 
5.6 14.1 
with Foam 
Invention B: K-C Ultra Thin Pad 
10.8 36.0 
with Foam 
Invention H: K-C Ultra Thin Pad 
3.5 N.D. 
with Foam 
Invention J: K-C Ultra Thin Pad 
5.2 N.D. 
with Foam 
Invention M: K-C Ultra Thin Pad 
8.5 14.2 
with Foam 
Invention W: K-C Ultra Thin Pad 
5.2 N.D. 
with Foam 
K-C Ultra Thin Pad with Pulp 
8.1 19.7 
P&G Whisper Excel 1.3 2.5 
(with wings) 
______________________________________ 
TABLE 14 
______________________________________ 
RATIO OF AVERAGE STIFFNESS OF OFFSET 
ADJACENT ZONES TO AVERAGE STIFFNESS OF 
OFFSET PERIPHERAL ZONES in Machine Direction 
Ratio of Averages 
______________________________________ 
Invention A: K-C Ultra Thin Pad 
2.5 
with Foam 
Invention B: K-C Ultra Thin Pad 
3.3 
with Foam 
Invention H: K-C Ultra Thin Pad 
N.D. 
with Foam 
Invention J: K-C Ultra Thin Pad 
N.D. 
with Foam 
Invention M: K-C Ultra Thin Pad 
1.7 
with Foam 
Invention W: K-C Ultra Thin Pad 
N.D. 
with Foam 
K-C Ultra Thin Pad with Pulp 
2.4 
P&G Whisper Excel 1.9 
(with wings) 
______________________________________ 
TABLE 15 
__________________________________________________________________________ 
PAD WIDTH MEASUREMENTS 
(A) 
CENTRAL (B) (D) 
ABSORBENT 
ABSORBENT 
(C) RESILIENT 
ZONE ZONE PAD LAYER 
WIDTH, WIDTH, WIDTH WIDTH 
inches inches inches 
inches 
PRODUCT millimeters 
millimeters 
millimeters 
millimeters 
__________________________________________________________________________ 
Invention A: 
1.25 
in. 2.835 
in. 3.62 
in. 
2.835 
in. 
K-C Ultra Thin 
32 mm. 72 mm. 92 mm. 
72 mm. 
Pad with Foam 
Invention H: 
1.25 
in. 2.125 
in. 3.75 
in. 
3.75 
in. 
K-C Ultra Thin 
32 mm. 
Pad with Foam 
Invention M: 
1.25 
in. 2.125 
in. 3.75 
in. 
3.75 
in. 
K-C Ultra Thin 
32 mm. 95 mm. 
Pad with Foam 
K-C Ultra 1.25 
in. 2.125 
in. 3.75 
in. 
Thin Pad with Pulp 
32 mm. 54 mm. 95 mm. 
N.D. 
P&G Whisper 
2.57 
in. 2.75 
in. 3.5 
in. 
Excel with Wings 
70 mm. 70 mm. 89 mm. 
N.D. 
__________________________________________________________________________ 
TABLE 16 
______________________________________ 
PAD WIDTH RATIOS 
A/B* A/C* A/D* 
100%, 100% 100% C/4 
PRODUCT percent percent percent 
in 
______________________________________ 
Invention A: 44 34 44 0.90 
K-C Ultra Thin 
Pad with Foam 
Invention H: 59 33 33 0.94 
K-C Ultra Thin 
Pad with Foam 
Invention M: 59 33 40 0.94 
K-C Ultra Thin 
Pad with Foam 
K-C Ultra Thin 
59 33 N.D. 0.94 
Pad with Pulp 
P&G Whisper 100 79 N.D. 0.88 
Excel with 
Wings 
______________________________________ 
TABLE 17 
______________________________________ 
CALIPER OF INVENTION A: 
K-C ULTRA THIN PAD WITH FOAM 
______________________________________ 
Central Absorbent Zone 
3.095 mm 
Center Adjacent Zones 
1.681 mm 
Offset Adjacent Zones 
1.699 mm 
Center Peripheral Zones 
1.130 mm 
Offset Peripheral Zones 
1.264 mm 
Peripheral Edges 0.376 mm 
______________________________________ 
TABLE 18 
______________________________________ 
CALIPER OF INVENTION B: 
K-C ULTRA THIN PAD WITH FOAM 
______________________________________ 
Central Absorbent Zone 3.11 mm 
Center Adjacent Zones 1.537 mm 
Offset Adjacent Zones 1.567 mm 
Center Peripheral Zones 
0.846 mm 
Offset Peripheral Zones 
1.223 mm 
Peripheral Edges 0.343 mm 
______________________________________ 
TABLE 19 
______________________________________ 
CALIPER OF INVENTION M: 
K-C ULTRA THIN PAD WITH FOAM 
______________________________________ 
Central Absorbent Zone 3.62 mm 
Center Adjacent Zones 1.330 mm 
Offset Adjacent Zones 1.650 mm 
Center Peripheral Zones 
1.105 mm 
Offset Peripheral Zones 
1.223 mm 
Peripheral Edges 0.316 mm 
______________________________________ 
TABLE 20 
______________________________________ 
CALIPER OF K-C ULTRA THIN PAD WITH PULP 
______________________________________ 
Central Absorbent Zone 
2.486 mm 
Center Adjacent Zones 
0.859 mm 
Offset Adjacent Zones 
0.705 mm 
Center Peripheral Zones 
0.292 mm 
Offset Peripheral Zones 
0.415 mm 
Peripheral Edges 0.363 mm 
______________________________________ 
TABLE 21 
______________________________________ 
CALIPER OF P&G 
WHISPER EXCEL (with wings) 
______________________________________ 
Central Absorbent Zone 
1.546 mm 
Center Adjacent Zones 
1.516 mm 
Offset Adjacent Zones 
1.574 mm 
Center Peripheral Zones 
0.480 mm 
Offset Peripheral Zones 
1.161 mm 
Peripheral Edges 0.444 mm 
______________________________________ 
Absorbency Testing 
The amount of body fluid which can be absorbed by the sanitary napkins 15, 
40, 50 and 80 can be determined using a saline solution in the following 
test. In performing this test, one napkin is sufficient. The sanitary 
napkin to be tested is first conditioned by leaving it in a room which is 
at 21.+-.1 degree Centigrade and at 50.+-.2% relative humidity for a 
period of two hours. If the napkin contains a peel strip, this is removed. 
The entire napkin, minus any peel strip, is weighed to the nearest 0.1 
gram. The napkin is then submerged in a beaker of stabilized isotonic 
saline which contains no preservatives. A suitable sterile saline is 
commercially sold by Baxter Healthcare Corp. of Deerfield, Ill. U.S.A. 
under catalog no. B3158-2. The napkin is totally submerged and is not bent 
or otherwise twisted or folded. The napkin is submerged for 10 minutes. 
The napkin is removed from the saline and suspended for two minutes in a 
vertical position to allow the saline to drain out of the napkin. The 
napkin is then placed with the bodyside cover face down on an absorbent 
blotter. The blotter can be filter paper no. ED 631-25 available from the 
Ahlstrom Filtration Inc., Mount Holly Springs, Pa. 17065 U.S.A. A uniform 
17.6 grams per square centimeter load is placed over the napkin to squeeze 
out excess fluid. The absorbent blotter is replaced every 30 seconds until 
the amount of fluid transferred to the absorbent blotter is less than 0.5 
grams in a 30 second period. Next, the napkin is weighed to the nearest 
0.1 gram and the dry weight of the napkin is subtracted. The difference in 
grams is the capacity of the napkin. 
Absorbency Testing was conducted for the entire napkins 15 and 50 and 
recorded as the "Total Capacity". The absorbency of the central absorbent 
zones 102 and 122 were also tested and recorded as the "Test Capacity." 
For sanitary napkins 50, the Third Embodiment, Invention B, the average 
Total Capacity of five samples was 38.2 grams. The average Test Capacity 
of five samples was 22.3 grams. 
For sanitary napkins 15, the First Embodiment, Invention W, the average 
Total Capacity of five samples was 37.9 grams. The average Test Capacity 
of five samples was 22.5 grams. 
For another set of five samples of the sanitary napkin 15, the First 
Embodiment, the average Total Capacity of five samples was 32.8 grams. The 
average Test Capacity of five samples was 21.4 grams. 
Samples of the K-C Ultra Thin Pad with Pulp, a commercially available 
sanitary napkin, were also tested. The average Total Capacity of the 
samples was 33.57 grams. The average Test Capacity of the samples was 
19.81 grams. 
Samples of a P&G Always Ultra Plus product, a commercially available 
sanitary napkin were also tested. The average Total Capacity of the 
samples was 37.02 grams. The average Test Capacity of the samples was 
14.08 grams. 
Other Embodiments 
While the invention has been described in detail with respect to specific 
embodiments thereof, it will be appreciated that those skilled in the art, 
upon attaining an understanding of the foregoing description, may readily 
conceive of alterations to, variations of and equivalents to these 
embodiments. Accordingly, the scope of the present invention should be 
assessed as that of the appended claims and any equivalents thereto. 
For example, the invention has been described in the context of sanitary 
napkins. But, the invention is also applicable to other absorbent 
articles, such as thick sanitary napkins, diapers, panty liners, 
incontinent products, training pants, bandages, and the like. In other 
embodiments, a separate baffle may be omitted and the resilient layer may 
also function as the baffle. 
The shape of the absorbent article may vary. It may be less rounded at the 
ends and more rectangular. More of the layers or all of the layers may be 
hourglass or racetrack in shape. The resilient layer may be positioned in 
a different location in reference to the other layers. The shape of the 
resilient layer may vary in comparison to the other layers. Other 
materials selected for the resilient layer may have a rebound resilience 
of about 50% or in the range of from about 25% to about 95%. The resilient 
layer may be discontinuous. For example, it may have holes in it. The 
number of layers of tissue may vary or may be eliminated. More or less 
adhesive may be used within the layers. A different absorbent means may be 
used, such as one which does not contain superabsorbent or hydrocolloidal 
material. The primary or significant absorbent means may not be the 
central stiffening means that resists twisting. The absorbent article, 
such as a sanitary napkin may have a central stiffening means to resist 
twisting, and one or more separate absorbent layers or other absorbent 
means that may not be as stiff as the central stiffening means.