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Patent 2154920 Summary

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(12) Patent Application: (11) CA 2154920
(54) English Title: ABSORBENT ARTICLE HAVING A THIN, EFFICIENT ABSORBENT CORE
(54) French Title: ARTICLE ABSORBANT A AME MINCE ET EFFICACE
Status: Deemed Abandoned and Beyond the Period of Reinstatement - Pending Response to Notice of Disregarded Communication
Bibliographic Data
(51) International Patent Classification (IPC):
  • A61F 13/15 (2006.01)
(72) Inventors :
  • FINCH, VALERIE VICTORIA (United States of America)
  • DILNIK, REBECCA LYN (United States of America)
  • GOGGANS, MARY WATT (United States of America)
  • LARSEN, JANET JESSIE (United States of America)
  • RESHESKI, KIM LARAE (United States of America)
(73) Owners :
  • KIMBERLY-CLARK WORLDWIDE, INC.
(71) Applicants :
  • KIMBERLY-CLARK WORLDWIDE, INC. (United States of America)
(74) Agent: BORDEN LADNER GERVAIS LLP
(74) Associate agent:
(45) Issued:
(22) Filed Date: 1995-07-28
(41) Open to Public Inspection: 1996-12-31
Availability of licence: N/A
Dedicated to the Public: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
08/475,324 (United States of America) 1995-06-30

Abstracts

English Abstract


Disclosed is an absorbent article having an absorbent core. The absorbent core
includes a primary absorbent member and a secondary absorbent member. The primary
absorbent member has a fluid distribution rate, expressed as the ratio of a stain area in
the primary absorbent member to a stain area in the secondary absorbent member,
along a X-Y direction greater than about 1.8 times faster than the secondary absorbent
member. The fluid distribution rate is expressed as a ratio of a stain area in the primary
absorbent member to a stain area in the secondary absorbent member five minutes after
a given volume of test fluid insults the absorbent core. The secondary absorbentmember has a substantial portion thereof composed of a non-absorbent polymeric
composition. The secondary absorbent member is superposed over a portion of the
primary absorbent member. In a preferred embodiment, the secondary absorbent
member has an aperture or orifice, that having an open surface area greater than about
20% of the secondary absorbent member surface area.


Claims

Note: Claims are shown in the official language in which they were submitted.


THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An absorbent article having an absorbent core comprising a primary absorbent
member and a secondary absorbent member, said primary absorbent member has a fluid
distribution rate along a X-Y direction greater than about 1.8 times faster than said
secondary absorbent member, said secondary absorbent member having a substantialportion thereof composed of a non-absorbent polymeric composition, said secondary
absorbent member is superposed over a portion of said primary absorbent member,
wherein said fluid distribution rate is expressed as a ratio of a stain area in said primary
absorbent member to a stain area in said secondary absorbent member five minutesafter a given volume of test fluid insults said absorbent core.
2. The absorbent article of claim 1 wherein said secondary absorbent member is
composed of from about 50% to about 95% of said non-absorbent polymeric
composition.
3. The absorbent article of claim 1 wherein said primary absorbent member has a
fluid distribution rate greater than about 2 times faster than said secondary absorbent
member.
4. The absorbent article of claim 1 wherein said primary absorbent member has a
fluid distribution rate greater than about 3 times faster than said secondary absorbent
member.
5. The absorbent core of claim 1 wherein said primary absorbent member and said
secondary absorbent member have coterminous outer perimeters.
6. The absorbent core of claim 1 wherein said secondary absorbent member has an
aperture extending through said secondary absorbent member thereby exposing saidprimary absorbent member for visual inspection.
7. The absorbent core of claim 1 wherein said non-absorbent polymeric composition
is selected from polyethylene, polypropylene, polyesters, and mixtures thereof.
13

8. The absorbent core of claim 1 wherein said secondary absorbent member has an
average density ranging from about 0.015 grams per cubic centimeter to about 0.1 grams
per cubic centimeter.
9. The absorbent core of claim 1 wherein said primary absorbent member is a
uncreped throughdried towel having a basis weight ranging from about 30 grams per
square meter to about 120 grams per square meter.
10. The absorbent core of claim 6 wherein said aperture has a diameter greater than
about 3 millimeters.
11. The absorbent core of claim 9 wherein said primary absorbent member is
apertured.
12. An absorbent article having an absorbent core comprising a primary absorbent
member and secondary absorbent member said primary absorbent member has a fluid
distribution rate along a X-Y direction greater than about 1.8 times faster than said
secondary absorbent member said secondary absorbent member composed of from
about 50% to about 95% of a non-absorbed polymeric composition, said secondary
absorbent member is superposed over a portion of said primary absorbent member,
wherein said fluid distribution rate is expressed as a ratio of a stain area in said primary
absorbent member to a stain area in said secondary absorbent member five minutesafter a given volume of test fluid insults said absorbent core.
13. The absorbent article of claim 12 wherein said primary absorbent member is an
uncreped throughdried towel.
14. The absorbent article of claim 12 wherein said primary absorbent member and
said secondary absorbent member have coterminous outer perimeters.
14

15. The absorbent article of claim 12 wherein said secondary absorbent member has
a predetermined surface area disposed toward a user and said secondary absorbentmember includes an aperture extending through said secondary absorbent member
wherein said aperture has an open surface area of greater than about 20% relative to
said surface area of said secondary absorbent member disposed toward the user
thereby exposing said primary absorbent member for visual inspection.
16. The absorbent core of claim 13 wherein said uncreped throughdried towel has a
basis weight ranging from about 45 grams per square meter to about 120 grams persquare meter.
17. A sanitary napkin having a thickness of less than about 5 millimeters with an
absorbent core comprising a primary absorbent member and a secondary absorbent
member said primary absorbent member includes a uncreped throughdried towel having
a basis weight ranging from about 30 grams per square meter to about 120 grams per
square meter said secondary absorbent member is immediately adjacent to and
superposed over a portion of said primary absorbent member so to be in liquid
communication with said primary absorbent member said secondary absorbent memberbeing composed of from about 50% to about 95% of a non-absorbent polymeric
composition and having an average density ranging from about 0.015 grams per cubic
centimeter to about 0.1 grams per cubic centimeter wherein said primary absorbent
member has a fluid distribution rate along a X-Y direction greater than about 1.8 times
faster than said secondary absorbent member wherein said fluid distribution rate is
expressed as a ratio of a stain area in said primary absorbent member to a stain area in
said secondary absorbent member five minutes after a given volume of test fluid insults
said absorbent core.
18. The absorbent core of claim 17 wherein said primary absorbent member is a
uncreped throughdried towel having a wet to dry tensile strength ratio greater than about
0.1.

19. The absorbent article of claim 17 wherein said secondary absorbent member has
a predetermined surface area disposed toward a user, said secondary absorbent
member includes a plurality of apertures extending through said secondary absorbent
member wherein said apertures have a combined open surface area of greater than
about 30% relative to said surface area of said secondary absorbent member disposed
toward the user thereby exposing said primary absorbent member for visual inspection.
20. The absorbent core of claim 17 wherein said non-absorbent polymeric
composition is selected from polyethylene, polypropylene, polyesters, and mixtures
thereof.
16

Description

Note: Descriptions are shown in the official language in which they were submitted.


21~492~
- PATENT
ABSOR8ENT ARTICLE HAVING A THIN, EFFICIENT ABSORBENT CORE
Field of the Invention
This invention relates to disposable absorbent articles and particularly to sanitary
napkins con~- ~ing multiple layers of absorbent. More particularly, this invention relates
to absorbent cores having improved wicking capability along an X-Y plane.
Back~round of the Invention
Generally, clispos~hl~ absorbent articles include, in their construction, an
absorbent core positioned bet~,veen a liquid-pemmeable cover and a liquid-i."pe....eable
15 baffle. The cover " ,alerial is generally designed to allow body ~ud~tes to pem~eale
through the cover so that the absorbent core can absorb the fluids. The baffle ...aterial is
generally fluid i.,~pe"~,eable and is positioned so that it is away from the body. As used
herein, the term ~abso,i,enl articles~ refers to products such as diapers, sanitary napkins,
training pants, inconlinent gamments, ovemight pads, panUliners, under~---. sh.eiis, as
20 well as other absorbent devices used for medical purposes sudh as surgical al~sG. ~enls.
Such artides are desig"ed to absorb body fluids, such as urine, menses, blood,
perspiration and other exc~"lent dischafged by the body. For purposes of clarity and
illu~l~tion only, the embodiments described herein will be in the form of a sanitaly
napkin, also referred to as catamenial pads, feminine pads, ovemight pads, pantiliners,
25 and panty shields which are designed to be wom by a woman to absorb menses and
other body fluids dischar~ed before, during, and after a menstrual period. Sucn products
are e~le"~al devices ~,vhich typically are held in position by a ga",~en( adhesive or by
mecl~an~ ' dlla~l""ent to an adjacent undergarment.
One continuing problem in the formation of absorbent articles is that the bodily30 exor~tions are usually directed at one portion of the absorbent pad, whereas the
absorptive capacity is spread over a greater area. In a convenlional sanitary napkin
made of multiple layers of cellulosic material, when fluid is absorbed by the wood pulp
fluff or similar cellulosic material, the capillary walls tend to collapse inward. This
c~"~pse prevents fluid from being conducted downward and subslanlially diminishes the
35 inherent resiliency of the cellulosic material.

215492~
This may create an ea~y failure problem as the fluid to be absorbed cannot be
efficiently spread through the absorbent. If the fluid does not spread throughout the
absorbent, it may run off the edge of the saturated zone.
A related problem is that after the capillaries collapse, fluid which would normally
5 be conducted downward tends to remain at or near the top surface of the napkin. This
contributes to the phenomenon known as rewet where the fluid is desorbed and contacts
the wearer, or contributes to fluid failing to penetrate the cover providing a wet,
u.,co",fo,lable napkin surface.
- Now an absorbent article has been invented which utilizes an absorbent having a
10 high wicking ability, especially for menses, as well as providing post-use visual signals to
the user that the absorbent capacity of the sanitary napkin is being fully utilized.
Summary of the lnvention
Briefly, this invention relates to absorbent articles, such as diapers, training pants,
inc~nlinent ga~"~e"t~, overnight pads, pantiliners, underarm shields and sanitary napkins.
For purposes of des~ption only, the preferred embodiment is des~il.ed as a sanitary
napkin which are designed to absorb menstrual fluid and other ex~...enls ~;I;scl)a.ged by
the body during a menstrual period. Accordingly, the abso bent article of this invention
20 includes an abso.l,enl core having a primary absorbent ,~e,.~l~er and a secondary
al,so. I,enl . "e, nber. The secondary absorbent member is s~.pe"~osed over at least a
portion of the primary abso, bent member and can be positioned so as to be in a face to-
faoe relat;onship with the primary absorbent member. The secondary abso.Lent -,e-"ber
contains a sulJstdnlidl amo~lnt of a nonabsorbent polymeric c~mposit;on which
25 conventionally are the.."oplastics. The primary absorbent member, which is an uncreped
throughdried towel, has a fluid distribution rate along a X-Y direction, greater than about
1.8 times faster than the secondary absorbent member. The fluid distribution rate is
e~ssed as the ratio of the stain area in the primary absorbent member to the stain
area in the secondary absorbent member after 5 minutes for a predetermined amount of
30 fluid insulting the absorbent core
More specifically, the invention provides an absorbent article having an
absorbent core compri.cing a primary absorbent member and a secondary absorbent
member, said primary absorbent member has a fluid distribution rate along a X-Y
direction greater than about 1.8 times faster than said secondary absorbent member,
35 said secondary absorbent member having a ~ul)~ lial portion thereof composed of a

215~92û
non-absorbent polymeric composition, said secondary absorbent memb~r is
superposed over a portion of said primary absorbent member, wherein said fluid
distribution rate is t;Al,.essed as a ratio of a stain area in said ~illl~y absorbent
member to a stain area in said secondary absorbent member five -.i.--~es after a given
volume of test fluid insults said absorbent core.
In another form, the invention provides an absoll,t;lll article having an
absorbent core compri~ing a primary absorbent member and secondary absorbent
member, said plilll~y absorbent member has a fluid distribution rate along a X-Ydirection greater than about 1.8 times faster than said secondary absoll,elll member,
said secondary absolbclll member composed of from about 50% to about 95% of a
non-absorbent polymeric composition, said secondary absoll~lll member is superposed
over a portion of said pl..~laly abso,l,enl member, wherein said fluid distribution rate
is e~,e~ed as a ratio of a stain area in said pllLU~ ~ absorbent member to a stain area
in said secondary absorbent member five .~.;...~les after a given volume of test fluid
insults said abso,l~"l core.
Finally, the invention provides a ~uu~ napkin having a thickness of less
than about S millimeters with an abso,l,elll core comrri~ing a primary absorbentmember and a secondary absorbent member, said pl l~y absofl,elll member in~ les
a uncreped throughdried towel having a basis weight ranging from about 30 grams per
square meter to about 120 grams per square meter, said secondary absoll.cil,l member
is immediately adjacent to and superposed over a portion of said pl~ y absorbentmember so to be in liquid co~ ul~ication with said plllll~.~ absoll~,ll member, said
secondary absorbent member being composed of from about 50% to about 95% of a
non-absorbent polymeric composilion and having an average density ranging from
about 0.015 grams per cubic centimeter to about 0.1 grams per cubic cen~imeter~
wherein said p~ absorbent member has a fluid distribution rate along a X-Y
direction greater than about 1.8 times faster than said secondary abso~l,t;nl member,
whe,ein said fluid distribution rate is ex~essed as a ratio of a stain area in said
primary absorbent member to a stain area in said secondary absorbent member fiveules after a given volume of test fluid insults said absorbent core.
2a

215~920
The general object of this invention is to provide an absorbent artide for
absorbing body fluids such as urine, menses, blood, etc. A more specific object of this
invention is to provide an absorbent article having at least two absorbent members
wherein the primary absorbent member has a greater wicking rate along an X-Y plane
than the first absorbent layer.
2b

- 21~4920
It is another object of this invention is to provide an absorbent article which utilizes
two separate and distinct absorbent members wherein the secondary absorbent member
indudes one or more areas of low density, such as an aperture, which allows visual
inspection of the primary absorbent member.
Other objects and advantages of the present inventjon will become more
appar~n~ to those skilled in the art in view of the following description and the
acco,.,panying drawings.
Brief DescriPtion of the Drawinas
Figure 1 is a perspective view of the invention iilustrated as a sanitary napkin.
Figure 2 is anolher embodiment of a sanitary napkin of this invention having an
aperture medially posi~ioned on a sanitary napkin.
Figure 3 is a cross-sectional view of the pad shown in Figure 2 taken along line~3.
Figure 4 is a cutaway sectional view of a pad having an hourglass shape with a
plurality of apertures below the cover for rapid fluid migration.
Detailed DescriPtion of the Preferred Embodiments
Refe.,ing to Figure 1, an absorbent article 10, in the form of a sanitary napkin, is
shown which can be wom by a female to absorb body fluids such as ."enses, blood,urine, and other e~ r~",enls d;sci~arged during a menstrual period. The abso,l,en~
article 10 can have a length of about 150 millimeters (mm) to about 300 mm and a width
of about 50 mm to about 150 mm. The sanitary napkin 10 has an oval shape. Other
shapes inciuding hourglass, dog bone, and racetrack are conle",plaled to be v~ithin the
scope of this invention. In a preferred embodiment, the absorbent article 10 can have a
caliperorthickness of less than about 15 mm, pr~ferdbly less than about 10 mm, and
most preferably less than about 5 mm.
The absorbent article 10 includes a liquid permeable bodyside cover 12, a liquid-
impermeable baffle 14, and an absorbent core 16 positioned between the cover 12 and
the baffle 14. The liquid-permeable cover 12 is designed to contact the body of the
wearer and can be constructed of a woven or nonwoven, natural or synthetic ",alerial
which is easily penetrated by body fluids. Suitabie materials include bonded carded
webs of polyester, polypropylene, polyethylene, nylon or other suitable bondable fibers.
Other polyolefins, such as copolymers of polypropylene and polyethylene, linear low

2154920
density polyethylene finely perforated film webs and net material also work well.
Particularly prerened are composite materials of a polymer and nonwoven fabric ."aterial.
To fa~ te ",~ lion of body fluids into the absorbent core 16 the cover 12 can include
apertures (not shown). Such apertures can be arranged along the longitudinal central
5 axis X-X if desired and are intended to increase the rate at which body fluids can
penetrate down into the absorbent core 16. When apertures are present body fluidwhich is deposited at or near the apertures rapidly "igrales into the absorbent core 16.
This helps maintain a perceivably drier surface than when the apertures are not
employed. Therefore while the apertures are not essential some functional advantages
10 are obtained in their use.
The liquid-permeable cover 12 can also be treated with a su, ~a- ~nl to make it
more hydrophilic and thereby aid in the absorption of the liquid. This su,raclanl can
include typical additions or applied materials like polysiloxine.
The liquid-impermeable baffle 14 is designed to be positioned distally from the
15 cover 12 and generally face the inner surface i.e. the crotch portion of an
und~rya,..,enl (not shown). The baffle 14 may permit the passage of air or vapor out of
the sanftary napkin 10 while blocking the passage of body fluids in liquid. The baffle 14
can be made from a micro~r"bossed polymeric film which is polyethylene Ot
polypropylene or it can be made from b'.c~n~ponent fllm. A pr~fe"ed ,"at~rial is a
polyeU,yle.~e film having a thickness of 0.025 mm to about 0.15 mm.
As shov~m the liquid-pe"~eable cover 12, the liquid-i",pem~eable baffle 14 and
the aiJs~,bent core 16 are coextensive. Altematively the cover 12 and bame 14 can in
combination enclose the abso.benl core 16. The cover 12 and bame 14 in those areas
where they are in face-to-face contact can be adhered using any suitable method that
does not leave a hard ~"~",ro~lable residue which would be annoying to the wearer.
Typical sealing methods include heat sealing adhesive sealing and ultl~son;c~llybonding on a line outward from the edge of the absorbent core 16 to form a fringe of
nalenal. This results in a neat bond line with less tendency for the ",ale,ial to be
pefro,dled than by heat sealing.

215~92~-
The absorbent core 16 comprises a primary absorbent member 18 and a
secondary absorbent member 20. The primary absorbent member 18 and secondary
absorbent member 20 can be joined together in a substantially parallel and coextensive
alignment, so that a major face of the primary absorbent member 18 is brought into
S in~i" ,ale contact with a major face of the secondary absorbent member 20 thereby
allowing the primary absorbent membe- 18 and secondary absorbent member 20 to be in
liquid communication. The primary absorbent member 18 generally has a fluid
distribution rate along an X-Y direction greater than about 1.8 times faster than the fluid
distribution rate of the secondary absorbent member 20, preferably the fluid distributlon
rate of the primary absorbent member 18 is greater than about 2 times faster than the
fluid distribution rate of the secondary absorbent member 20, and more p~eferably the
fluid distribution rate of the primary absorbent member 18 is greater than about 3 times
faster than the fluid distribution rate of the secondary absorbent member 20. The fluid
distribution rate is expressed as the ratio of a stain area in the primary abso,Lenl
member 18 to the stain area in the secondary absorbent member 20 five minutes after a
given volume of test fluid, typically bovine blood, insults the abso.bent core 16.
The primary absorbent member 18 is an uncreped throu-yl,dried towel (UCTAD)
having a basis weight ranging from about 30 grams per square meter to about 120 grams
per square meter. Generally, the primary member of the present invention is p~pan~d by
a ,~cess as disrlosed in U.S. Patent No. 5,048,589 issued to Crook et al. on
Septe-,lber 17,1~91; U.S. Patent No. 5,399,412 issued to Sudall et al. on March 21,
1995; and U.S. Serial No. 08/447578 filed on May 23,1995, each c~",.~only assi~ned to
~e Kimberly-Clark Co"~ordtion, the entire dis~-losure of each is incoi~ ordted herein and
made a part hereof. Generally, the pr~cess includes the steps of fonning a fumish of
cellulosic fibers, water, and a chemical debonder; depositing the fumish on a traveling
foraminous belt thereby forming a fibrous web on top of the traveling belt; subjecting the
fibrous web to noncompressive drying to remove water from the fibrous web and
removing the dried fibrous web from the traveling foraminous belt. The uncf~ped
throughdried tissue co",prising the primary absorbent member 18 possesses a high level
of absorbent capacity, absorbency rate, strength, and softness. In a pr~fe"ed
embodiment, the primary absorbent member 18 has a dry tensile strength of less than
about 11,000 grams, prefe,ably less than 6,000 grams, and more preferably less than
about 2,200 grams. In a particularly preferred embodiment, the primary absorbentmember 18 is an uncreped throughdried towel having a wet-to-dry tensile strength ratio

215~920
greater than about 0.1 The wet:dry ratio is simply the ratio of the wet tensile strength
divided by the dry tensile strength. It can be expressed using the machine direction
tensile strength the cross machine direction tensile strength or the geometric mean
tensile strength.
The primary absorbent member 18 can be embossed or apertured (not shown) to
lessen the stiffness of the UC~AD towel. Methods for embossing or aperturing theprimary absorbent member 18 are known to those skilled in the art. When the primary
absorbent member 18 has a plurality of apertures the size of the openings should not
exceed 2 millimeters in diameter since this may effect the capacity of the primary
absorbent member 18 to absorb fluid exudates or its ability to effectively utilize the
capadty of the primary absorbent member 18. Pleferably, the apertures are less than 1
millimeter in diameter and more preferably thèy are less than 0.5 millimeters. In addition
to the size of the apertures it is i" ,po, lant that the total open surface area of the
apertures should not exceed 40 percent of the surface area of the primary absorbent
member 18 disposed toward the cover 12. Other geometric configurations such as
square rectangular triangular etc. can be used for the apertures.
The secondafy absG, ~ent member 20 is a blend of meltblown fiber and staple
fibers generally known as coform. Basically the "~etl ,od of manufacturing coform
involves extruding a molten non~bso,l,ent polymeric ",atenal through a die head into fine
~a,ns and attenuating the slr~a,ns by converging flow of high velodty heated gass~rF ed from the no7,1es to break the polymer slr~a",s into di3conlin-~0us mi~ e~a of
small dia",eler. In general the resulting microfibers have an average fiber density
dia",eter of up to about 10 microns. This primary gas stream is merged with a secondafy
gas streaming containing individualized wood pulp fibers so as to integf~te the two
different fibers into a single step. A wide variety of the",~oplastic polymers is useful in
forming the meltblown m;crofibers. Such the."~opl?slic polymers include polyolefins such
aspolypropylene polyethylene polyamides polyesters andther"~opla~licelast~,.,er~such as polyurethane. The process is described in greater detail in U.S. Patent
No. 4 100 324 issued to Anderson et al. on July 11 1978 and assigned to the co"~,non
assignee the disdosure of which is incorporated herein and made a part hereof. It is
critical to the invention that a substantial portion of the seGondary absorbent member be
composed of the nonabsorbent polymeric composition. Prefef~bly the secondary
absorbent member 20 is composed of from about 50 percent to about 95 percent of the
nonabso,L,ent polymeric composition more prefercbly it is composed from about 50percent to about 80 percent of the nonabsorbent polymeric composition and most
pfeferably from about 50 percent to about 75 percent of the nonabsorbent polymeric

21~920
composition. Desirably the secondary absorbent member 20 has an average density
ranging from about 0 015 grams per cubic centimeter to about 0.1 grams per cubicoentimeter and prererdbly from about 0.02 grams per cubic centimeter to about 0.09
grams per cubic centimeter. It has been discovered that when the nonabsorbent
" 5 polymeric composition is less than about 50 percent fluid insulting the cover and
migrating down will be absorbed into the slower wicking secondary absorbent
member 20. Thus resulting in the problems described above as well as reducing the
effectiveness and utilization of the absorbent core 16.
The sanitary napkin 10 can include a transfer layer (not shown). The l,ansrer
10 layer is designed to facilitate the movement of fluid downward from the cover and provide
a means for sepa(aling the cover 12 from the absorbent core 16 to provide a dry
sensat,on and addit;onal cG",ro,l to the user. The l,a,~srer layer, if used, is pr~fen~ly
positioned bet~rlecn the cover 12 and the second absorbent member 20 and can be
configured to correspond to the abso,l,ent core 16. A desc~i~,lion of a If ~,)srer layer is
15 taught in U.S. Pat. No. 4 798 603 issued to Meyer et al. and assigned to the pr~sent
assignee. This patent is inco".or~led herein and made a part hereof.
Refe" ing to Figure 2 the abso, L,enl article 50 is depicted as having a cover 52, a
baffle 54 a primary abso,L,~nl member 56 and a secondary abso,bent member 58. The
seoondaly absorbent member 58 includes an area 60 having a lower dens~y than the20 surrounding secondary abso,6en~ member 58 or the primary abso, l,enl member 56. The
area 60 has a density of less than about 0.01 grams per cubic cenG",eler and pr~fe,a~ly
less than 0.005 grams per cubic centimeter. Desirably the area 60 is an aperture or
cavity. The aperture 60 is approp, ialely configured and dimensioned so as to allow the
wearer to visually inspect the primary absorbent member 56. The aperture 60 has an
25 open surfaoe greater than about 20 percent pr~ferdbly greater than 30 pe.~. lt and most
l~r~fe,dbly greater than 50 percent of the surface area of the secondary absorbent
",e",ber 58 disposed toward the cover 52. The aperture 60 extends through the
secondary absorbent member 58 thereby exposing the primary absorbent member 56.
This allows for rapid fluid absorption into the primary absorbent member 56 and for visual
30 inspection of the primary absorbent member 56.
Refe(ring to Figure 3 a cross-section of Figure 2 along line 3-3 is shown.
Adjacent major faces 62 and 64 define adjacent major surfaces of the primary absorbent
member 56 and the secondary absorbent member 58 respectively. The surfaces 62 and
64 can be bonded together by point bonds to forrn a unitary structure or can be bonded
35 together using other means known in the art such as construction adhesives that are
known to those skilled in the art. The major surfaces 62 and 64 are secured together in a

21SA 920
manner that will not occlude the fluid flow through the secondary absorbent member 58
or result in a stiff, uncomfortable prodùct.
Referring to Figure 4, an absorbent article 100 is shown which contains a
cover 102, a baffle 104, a primary absorbent member 106, and a secondary absorbent
member 108. The secondary absorbent member 108 includes a plurality of low density
areas 110. P(efe~bly the low density areas 110 are apertures or cavities hàving a
~ia."eter greater than about 3 millimeters which extend through the secondary abso,L,ent
member 108 to expose the primary absorbent member 106. The apertures 110 have a
- combined open surface area greater than about 20 percent, preferably greater than
about 30 percent, more preferably greater than about 50 percent, relative to the total
surface area of the secondary absorbent member 108 disposed toward the cover 102.
The sanitary napkin 10, 50 and 100 can include lateral e~ctensions, (not shown)
generally known to those skilled in the art as wings, tabs and panels. The wings are
designed to wrap around the outer surface of the crotch portion of a user's
undergarment. Typically, at least one of the wings has an adhesive strip atla-;l ,ed to one
surface, pfeferdbly it is the upper surface of one wing. To protect the adhesive from
pr~...alurely or inadYertently adhering to a surface prior to the intended use, the adhesiYe
can be covered by a releas~hle peel strip.
- In accor~Jance with the invention, the t~ u.ng examples are being presented for
the purpose of illusl.dlion only. In the exa",r'es, the absorbency of the sanitary napkin
was determined by laying the product on a flat level surface. The fun-,lionality of the
absG,l.entwas evaluated by measuring the surface area of the top and bottom stains of
the compos;les
The ..,a~e,ials used in evaluating the functionality include a 20 cc syringe, an25 acrylic block further described herein for targeting the test fluid onto the abso.l,ent article,
a slopJ~tcl~, and boYine blood, available from Cocalico 8iologicals, Inc., SteYens Road,
Rear..aloJ/n, PA 17567, which was used as the test fluid. The acrylic block measures 4
inches wide x 4 inches long and has a thickness of 1 inch. A oval opening measuring 1/2
inch wide x 2 inches long is provided in the center of the block. An indicator mark is
30 positioned at the center on both sides of the opening. The indicator mark assists the
placement of the syringe and delivery of the test fluid.
The test method used in evaluating the sanitary napkins involves first conditioning
the sanitary napkin by leaving it in a room which is at 21 + 1C and at 50 1 2% relabve
humidity for a period of two hours. The block was then placed on the center of the pad
35 with the long portion of the opening parallel with the longitudinal edge of the pad. The
test quantity of bovine blood was drawn up into the syringe and was dispensed, at the

215~920
indicator mark, into the opening at a rate of approximately 0.6 - 0.7 milliliters per second.
A total of 6 cubic centimeters (cc) of bovine blood was used to insult the absorbent
artides in Examples 1-24. The results of these absorbent article appears in Table 1
(colnpal~live Examples), and Table 2. A total of 10 cc of bovine blood was used to
5, insult the absorbent articles in Examples 25-48. The results of these absorbent article
appea~ in Table 3 (Comparative Exar"p'~s), and Table 4. When the opening was void
of test fluid, the block was removed and wiped clean in pr~paraliol1 for the next pad to be
tested. After 5 minutes, the layers of the insulted pad were carefully separated and the
area of stain was measured on each absorbent layer.
COMPARATIVE EXAMPLES 1 - 10
Co""-,er~;ally available product was tested in accordance with the method described
above. Refening to Table 1, the area of the stain for a 6 milliliter insult of bovine blood
15 v~ras measured after 5 minutes.
TABLE 1
Sample Descn~.tion TopBottom Ratio
Always~)Ultra Maxi ' 6.305.27 0.82
2 New Freedom~E9 Ultra Thin Pads With StayPut 5.55 3.02 0.54
Tabs
3 Always~) Maxi Fluff ' 1.891.48 0.78
4 Sure & Natural~) Ultra Thin 3 3.493.27 0.94
Stayfree~) Ultra Thin 3 5.853.86 0.66
6 Kotex~ Maxi Pads 2 3.020.1 0.03
7 New Freedom~ Maxi Pads 2 8.3 0.1 0.01
8 New Freedom~) Thin Pads 2 3.52.76 0.79
9 Kotex~ Thin Pads 2 5.985.19 0.87
New Fr~edGn~ Ultra Thin Pads 2 5.933.71 0.63
~- Available from Procter & Gamble, Cinc;nnali, OH 45202.
2_ Available from Kimberly-Clark Corp., Neenah, Wl 54956.
3- Available from Personal Product Co., Milltown, NJ 08850
EXAMPLES 11 - 24
Referring to Table 2, which is illustrative of the present invention, stain
dimensions for a 6 millimeter insult of bovine blood after 5 minutes is shown. The test
absorbent core of the sanitary napkin measured 178 millimeters in length and 76
35 millimeters in width.

2154~2()
TABLE 2
Sample Description Top~ottom Ratio
11 2 layers of 135 gsm coform ~ having a 24 mm x 1.765.32 3.02
62 mm center aperture and 2 layers of 105 gsm
UCTAD towel
12 2 layers of 135 gsm coforrn and 2 layers of 105 1.15 5.28 4.59 gsm UCTAD towel.
13 2 layers of 135 gsm coform having a 24 mm x 62 2.106.20 2.86
mm center aperture and 2 layers of 105 gsm
UCTAD towel.
14 2 layers of 135 gsm coform and 3 layers of 1.614.62 2.87
60 gsm UCTAD towel.
1 layer of 135 gsm coform; 1 layer of 225 gsm 1.493.90 2.63
cellulose pulp paper that is microstrained and 2
layers of 105 gsm UCTAD towel.
16 1 layer of 135 gsm coform and 1 layer of 225 2.735.83 2.14
gsm cellulose pulp paper that is microstrained
each having a 24 mm x 62 mm center aperture
and 3 layers of 60 gsm UCTAD towel.
17 1 layer of 135 gsm coform; 1 layer of 225 gsm 1.875.59 2.99
cellulose pulp paper that is microstrained; and 3
layers of 60 gsm UCTAD towel.
18 2 layers of 135 gsm coform having a 24 mm x 62 5.238.46 1.62
mm center aperture and 225 gsm cellulose pulp
paper that is .~..c.~strdined.
19 1 layer of 135 gsm coform and 1 layer of 225 2.945.91 2.01
gsm cellulose pulp paper that is microstrained
each having a 24 mm x 62 mm center ape~ture
and 1 layer of 225 gsm cellulose pulp paper that
is m'-~osl,ained.
1 layer of 225 gsm cellulose pulp paper that is 6.91 6.24 0.90
microstrained having a 24 mm x 62 mm center
aperture and 2 layers of 105 gsm UCTAD towel.
21 1 layer of 135 gsm coform and 1 layer of 225 2.575.93 2.31
gsm cellulose pulp paper that is microstrained
each having a 24 mm x 62 mm center aperture
and 2 layers of 105 gsm UCTAD towel.
22 2 layers of 135 gsm coform having a 24 mm x 62 2.077.04 3.40
mm center aperture and 6 layers of 60 gsm
UCTAD towel.
23 1 layer of 135 gsm coform with a 24 mm x 62 mm 1.937.71 3.99
center aperture, 2 layers of 60 gsm UCTAD each
with a 24 mm x 64 mm center aperture, 1 layer of
135 gsm coform with a 24 mm x 62 mm center
aperture and 2 layers of 60 gsm UCTAD towel.
24 1 layer of 135 gsm coform with a 24 mm x 62 mm 2.268.62 3.81
center aperture, 3 layers of 60 gsm UCTAD towel
each with a 24 mm x 64 mm center aperture, and
3 layers of 60 gsm UCTAD towel.
* coform composition was 60:40 polymer to pulp ratio.

21~4920
COMPARATIVE EXAMPLES 25 - 34
Commercially available product was tested in accordance with the method
described above. Referring to Table 3, the area of the stain for a 10 m " ' ter insult of
bovine blood was measured after 5 minutes.
TABLE 3
Sample Desc- iplion TopBoffom Ratio
Always~) Ultra Maxi 10.69.99 0.94
26 New Freedom~ Ultra Thin Pads With StayPut 7.955.78 0.72
Tabs
10 27 Always~ Maxi Fluff 2.712.94 1.08
28 Sure & Natural~) Ultra Thin 5.62 6.2 1.10
29 Stayfree~ Ultra Thin 8.068.39 1.04
Kotex~) Maxi Pads 3.76 0.1 0.03
31 New Freedom~) Maxi Pads 5.982.17 0.38
32 New Freedom~ Thin Pads 4.515.32 1.18
33 Kote~)Thin Pads 7.177.17 1.00
- 15 34 New Freedom~ Ultra Thin Pads 10.978.86 0.81
EXAMPLES 35 - 48
Referring to Table 4, which is illustrative of the pr~senl invenUon, stain
dil.,el~sbns for a 10 millimeter insult of bovine blood after 5 minutes are shown.
TA8LE 4
Sample Desc- iplion TopRoffom Ratio
2 layers of 135 gsm coform ~ having a 24 mm x 2.73 7.6 2.78
62 mm center aperture and 2 layers of 105 gsm
UCTAD towel.
36 2 layers of 135 gsm coforrn and 2 layers of 105 2.99 8.22 2.75
gsm UCTAD towel.
37 2 layers of 135 gsm coform having a 24 mm x 62 2.9810.72 3.60
mm center aperture and 2 layers of 105 gsm
UCTAD towel.
38 2 layers of 135 gsm coform and 3 layers of 2.247.71 3.44
60 gsm lJCTAD towel.
39 1 layer of 135 gsm; 1 layer of 225 gsm cellulose 2.81 7.57 2.69
pulp paper that is microstrained and 2 layers of
105 gsm UCTAD towel.
1 layer of 135 gsm coform and 1 layer of 225 gsm 3.69 9.25 2.51
cellulose pulp paper that is microstrained each
having a 24 mm x 62 mm center aperture and 3
layers of 60 gsm UCTAD towel.
41 1 layer of 135 gsm coform; 1 layer of 225 gsm 3.258.36 2.57
cellulose pulp paper that is microstrained; and 3
layers of 60 gsm UCTAD towel.

21S4~20
- 42 2 layers of 135 gsm coform having a 24 mm x 62 4.73 12.57 2.66
- mm center aperture and 225 gsm cellulose pulp
paper that is microstrained
43 1 layer of 135 gsm coform and 1 layer of 225 gsm 4.58 9.18 2.00
- cellul~se pulp paper that is microstrained each
having a 24 mm x 62 mm center aperture and 1
!~11 layer of 225 gsm cellulose pulp paper that is
microstrained.
44 1 layer of 225 gsm cellulose pulp paper that is - 9 76 8.89 0.91
microstrained having a 24 mm x 62 mm center
aperture and 2 layers of 105 gsm UCTAD towel.
1 layer of 135 gsm coform and 1 layer of 225 gsm 3.62 8.47 2.34
cellulose pulp paper that is microstrained each
having a 24 mm x 62 mm center aperture and 2
layers of 105 gsm UCTAD towel.
46 2 layers of 135 gsm coform having a 24 mm x 62 3.84 9.25 2.41
mm center aperture and 6 layers of 60 gsm
UCTAD towel.
47 1 layer of 135 gsm coform with a 24 mm x 62 mm 1.68 5.09 3.03
center aperture,2 layers of 60 gsm UCTAD each
~,vith a 24 mm x 64 mm center aperture,1 layer of
135 gsm coform with a 24 mm x 62 mm center
aperture and 2 layers of 60 gsm UCTAD towel.
48 1 layer of 135 gsm coform with a 24 mm x 62 mm 2.96 11.25 3.8û
center apefture, 3 layers of 60 gsm UCTAD towel
each u/ith a 24 mm x 64 mm center aperture, and
3 layers of 60 gsm UCTAD towel.
While the invention has been described in conjunction several specific
embodiments, it is to be understood that many alle,nali~/es, ..,o~ ions, and vanalions
will be appa~ to those skilled in the art in light of the foregoing desc iption.Accordingly, this invention is intended to embrdce all such ~lle..-ati~/es, mod~ ions and
~,aria~ons which followed in the spirit and scope of the appended claims
12

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

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Event History

Description Date
Inactive: IPC deactivated 2011-07-27
Inactive: First IPC derived 2006-03-11
Inactive: IPC from MCD 2006-03-11
Application Not Reinstated by Deadline 2002-07-29
Time Limit for Reversal Expired 2002-07-29
Deemed Abandoned - Failure to Respond to Maintenance Fee Notice 2001-07-30
Application Published (Open to Public Inspection) 1996-12-31

Abandonment History

Abandonment Date Reason Reinstatement Date
2001-07-30

Maintenance Fee

The last payment was received on 2000-06-22

Note : If the full payment has not been received on or before the date indicated, a further fee may be required which may be one of the following

  • the reinstatement fee;
  • the late payment fee; or
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Please refer to the CIPO Patent Fees web page to see all current fee amounts.

Fee History

Fee Type Anniversary Year Due Date Paid Date
MF (application, 2nd anniv.) - standard 02 1997-07-28 1997-06-25
MF (application, 3rd anniv.) - standard 03 1998-07-28 1998-06-25
Registration of a document 1998-09-25
MF (application, 4th anniv.) - standard 04 1999-07-28 1999-06-14
MF (application, 5th anniv.) - standard 05 2000-07-28 2000-06-22
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
KIMBERLY-CLARK WORLDWIDE, INC.
Past Owners on Record
JANET JESSIE LARSEN
KIM LARAE RESHESKI
MARY WATT GOGGANS
REBECCA LYN DILNIK
VALERIE VICTORIA FINCH
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Description 1996-10-23 14 746
Abstract 1996-10-23 1 25
Claims 1996-10-23 4 151
Drawings 1996-10-23 2 27
Representative drawing 1998-01-06 1 9
Courtesy - Abandonment Letter (Maintenance Fee) 2001-08-26 1 185
Reminder - Request for Examination 2002-04-01 1 119
Prosecution correspondence 1996-04-03 1 20