Note: Descriptions are shown in the official language in which they were submitted.
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BODY FITTING COMPOUND SANITARY NAPKIN
FIELD OF THE INVENTj~,~,
The present invention relates to disposable sanitary napkins. More
particularly, the present invention relates to a compound sanitary napkin
comprising a primary absorbent member and a base member, wherein the
primary absorbent member comprises a primary absorbent element.
BACKGROUND
In their simplest form, disposable sanitary napkins comprise an
absorbent element (sometimes referred to as an absorbent core) interposed
between ,a fluid pervious body-facing sheet (sometimes referred to as a
topsheet) and a fluid impervious garment-facing sheet (sometimes referred
to as a backsheet). The absorbent element is, of course, intended to
receive and contain menses and other vaginal discharges. The body-facing
sheet is intended to provide more or less comfortable and dry-feeling
contact with body surfaces while allowing free passage of fluids
therethrough into the absorbent element. The garment-facing sheet is
intended to prevent menses or other vaginal discharges which are expelled
or which escape from the absorbent element from soiling the user's
garments. In addition to the three functional elements mentioned above,
disposable sanitary napkins are generally provided with means for
supporting the device adjacent the user's crotch area, even as the user
moves, where it can most effectively perform its intended function.
Typically, sanitary napkins are provided with an adhesive attachment means
for securing the device to the inner crotch area of the user's undergarments.
While previously known sanitary napkins do perform their intended
function, each conventional design suffers from certain deficiencies in one or
more of absorbency of body fluids, protection of the user's garments from
soiling, and/or physical comfort to the user.
. With respect to disposable sanitary napkins, at least two general
classes presently exist. One such class is identified as being intended for
the absorption of medium to high menstrual flows. These sanitary napkins
offer a relatively high absorptive capacity. Absorptive capacity is commonly
achieved by providing the sanitary- napkin with a relatively thick and bulky
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absorbent member. While having a relatively high absorptive capacity, the
bulkiness of the absorbent member may cause a certain degree of wearing
discomfort. A second class of sanitary napkins are intended for light or low
menstrual flows and are commonly referred to as pantiliners or pantishields.
Sanitary napkins of this class, as a group, are thinner, somewhat more
flexible and generally more comfortable than those of the first class.
However, sanitary napkins of the second class typically lack the absorptive
capacity of sanitary napkins of the first class.
One attempt to provide the benefits of the previously described two
classes of sanitary napkins into a single compound sanitary napkin is
disclosed in commonly assigned U.S. Patent No. 4,425,130 issued to
DesMarais on January 10, 1984. The compound sanitary napkin of
DesMarais comprises a primary menstrual pad and a panty protector joined
to one another at their corresponding ends in such a manner that the two
constituents are free to move relative to one another along essentially their
entire common length. In use, the relative freedom of movement between
the primary menstrual pad and the panty protector serves to maintain the
primary menstrual pad adjacent the user's crotch region while the panty
protector remains associated with the user's undergarment. While the
relative freedom of movement between the primary menstrual pad and the
panty protector serves to maintain the primary menstrual pad near the user's
crotch region, this freedom of movement may lead to a lack of stability if the
primary menstrual pad moves laterally beyond the side edges of the panty
protector, providing an opportunity for soiling the user's undergarment.
While prior art absorbent articles such as sanitary napkins have
addressed some of the problems of achieving a compound sanitary napkin,
they have not addressed the problems to the extent of or in the manner of
the present invention. Therefore, a primary object of the present invention is
to provide an improved compound sanitary napkin.
SUMMARY
The present invention relates to a body fitting compound sanitary
napkin comprising a primary absorbent member and a secondary absorbent
member. The primary absorbent member has a longitudinal length, a
transverse width, a thickness, a pair of longitudinal sides and a pair of
transverse ends, and comprises a primary absorbent element and a fluid
pervious cover superimposed on- the primary absorbent element. The
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secondary absorbent member has a longitudinal length, a transverse width,
a thickness, a pair of longitudinal sides and a pair of transverse ends, and
comprises a fluid pervious body-facing sheet, a fluid impervious garment-
facing sheet joined to the fluid pervious body-facing sheet and a secondary
absorbent element positioned between the fluid pervious body-facing sheet
and the fluid impervious garment-facing sheet. The primary absorbent
member is affixed to the fluid pervious body-facing sheet side of the
secondary absorbent member by union means. A ratio of the thickness of
the primary absorbent member to the transverse width of the primary
absorbent member is between 0.05 and 1.5. The primary absorbent
member has a capacity for absorbing at least 70 % of loaded menstrual fluid
of between 2 and 30 grams when the sanitary napkin is applied to a female
body and used.
The present invention also relates to a body fitting compound sanitary
napkin comprising a primary absorbent member and a secondary absorbent
member. The primary absorbent member has a longitudinal length, a
transverse width, a thickness, a pair of longitudinal sides and a pair of
transverse ends, and comprises a primary absorbent element and a fluid
pervious cover superimposed on the primary absorbent element. The
primary absorbent element comprises hydrogel-forming polymers and
hydrophilic fibers. The secondary absorbent member has a longitudinal
length, a transverse width, a thickness and a pair of longitudinal sides and a
pair of transverse ends, and comprises a fluid pervious body-facing sheet, a
fluid impervious garment-facing sheet joined to the fluid pervious body-
facing sheet and a secondary absorbent element positioned between the
fluid pervious body-facing sheet and the fluid impervious garment-facing
sheet. The primary absorbent member is affixed to the fluid pervious body-
facing sheet side of the secondary absorbent member by union means. A
ratio of the thickness of the primary absorbent member to the transverse
width of the primary absorbent member is between 0.05 and 1.5. The
primary absorbent element includes the hydrogel-forming polymers of
between 10 % and 60 %.
BRIEF DESCRIPTION OF THE DRAWI[yGS
While the spec~cation concludes with claims particularly pointing out
and distinctly claiming the present invention, it is believed that the present
invention will be better understood from the following description in
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conjunction with the following drawings, in which like reference numbers
identify identical elements and wherein:
FIG. 1 is a top plan view of one embodiment of the compound
sanitary napkin of the present invention;
F1G. 2 is a cross-sectional view taken along the longitudinal centerline
L of the compound sanitary napkin shown in FIG. 1;
FIG. 3 is a cross-sectional view taken along the transverse centerline
T of the compound sanitary napkin shown in FIG. 1.;
FIG. 4 is a cross-sectional view of another embodiment of a
compound sanitary napkin of the present invention;
FIG. 5 is a top plan view of a unfolded fluid pervious cover with a
primary absorbent element of a primary absorbent member of the present
invention.
FIG. 6 is a top plan view a compound sanitary napkin of the present
invention showing union means;
FIG. 7 is a cross-sectional view taken along VII - VII line shown in
FIG. 1;
FIG. 8 is a cross-sectional view of another embodiment of a
compound sanitary napkin of the present invention;
FIG. 9 is a cross-sectional view of another embodiment of a
compound sanitary napkin of the present invention;
FIG. 10 is a top plan view of another embodiment of a compound
sanitary napkin of the present invention;
FIG. 11 is a top plan view of another embodiment of a compound
sanitary napkin of the present invention;
FIG. 12 is a fragmentary view showing the sectioned sanitary napkin
and panty in place on a user.
DETAILED DESCRIPTION OF THE INVENTION
This invention is of a body fitting compound sanitary napkin which
exhibits absorbency for bodily fluids, the protection of the user's garments ,
from soiling, and physical comfort to the user. The term "sanitary napkin",
as used herein, refers to an article which is worn by females adjacent to the
,
pudendal region and which is intended to absorb and contain the various
exudates which are discharged from the body (e.g., blood, menses, and
urine) and which is intended to be discarded after a single use (i.e., it is
not
intended to be laundered or othervvise restored or reused). The term
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"compound sanitary napkin", as used herein, refers to a sanitary napkin
. comprised of separate constituents joined to one another to form a unitary
structure. Interlabial devices which reside partially within and partially
external of the wearer's vestibule are also within the scope of this
invention.
As used herein, the term "pudendal" refers to the externally visible female
genitalia and is limited to the labia majora, the labia minora, the clitoris,
and
the vestibule.
Referring now to FIGS. 1 - 3, there is shown one preferred
embodiment of a compound sanitary napkin 20 of the present invention.
The compound sanitary napkin 20 has two surfaces, a body contacting or
facing surface 20A, and a garment contacting or facing surface 20B. The
compound sanitary napkin 20 has a first end region 27, a central region 28,
a second end region 29, longitudinal sides 16 and transverse ends 18. The
compound sanitary napkin 20 has two centerlines, a longitudinal centerline L
and a transverse centerline T. The term "longitudinal", as used herein,
refers to a line, axis or direction in the plane of the compound sanitary
napkin that is generally aligned with (e.g., approximately parallel to) a
vertical plane which bisects a standing wearer into left and right body halves
when the compound sanitary napkin is worn. The terms "transverse" or
"lateral", as used herein, are interchangeable, and refer, to a line, axis, or
direction which ties within the plane of the compound sanitary napkin that is
generally perpendicular to the longitudinal direction.
As can be seen in FIGS. 1 - 3, the compound sanitary napkin 20
comprises a primary absorbent member 30 and a secondary absorbent
member (base member) 50 joined together by union means 70. The primary
and secondary absorbent members each have corresponding body facing
and garment facing surfaces. The primary absorbent member 30 has
longitudinal sides 24 and transverse ends 25 which together form the
periphery 26 of the primary absorbent member 30. The primary absorbent
member 30 also has a longitudinal length PL and a transverse width PW,
and a thickness PT. The secondary absorbent member 50 has longitudinal
sides 21 and transverse ends 22 which together form the periphery 23 of the
secondary absorbent member 50 and the compound sanitary napkin 20.
The secondary absorbent member 50 has a longitudinal length SL and a
transverse width SW, and a thickness ST. As shown in FIG. 1, preferably,
the compound sanitary napkin 20 has flaps 33 extending from the
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longitudinal sides 21 of the secondary absorbent member 50 in the central
region 28 of the compound sanitary napkin 20. .
The primary absorbent member 30 is, as its name implies, that
constitute of the compound sanitary napkin 20 intended to absorb the bulk r
of bodily fluids discharged by the user. The primary absorbent member 30
has generally rectangular shape extending in the longitudinal direction along
the longitudinal centerline L. In a preferred embodiment, the longitudinal
length PL may be generally equal to the longitudinal length SL of the
secondary absorbent member 50. The transverse width PW may be
generally narrower than the transverse width SW of the secondary
absorbent member 50. The primary absorbent member 30 comprises a
primary absorbent element such as an absorbent core 34, a fluid pervious
cover such as fluid pervious topsheet 32 superimposed on the absorbent
core 34.
The topsheet 32 is preferably compliant, of feeling, and non-irritating
to the wearer's skin. Further, the topsheet 32 is fluid pervious, permitting
fluid to readily penetrate through its thickness. A suitable topsheet 32 may
be manufactured from a wide range of materials such as woven and
nonwoven materials; polymeric materials such as apertured formed
thermoplastic films, apertured plastic films, and hydroformed thermoplastic
films; porous foams; reticulated thermoplastic films; and thermoplastic
scrims. Suitable woven and nonwoven materials can be comprised of
natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g.,
polymeric
fibers such as polyester, polypropylene, or polyethylene fibers); or from a
combination of natural and synthetic fibers. A preferred topsheet comprises
an apertured formed film. Apertured formed films are preferred for the
topsheet because they are pervious to body exudates and yet non-
absorbent and have a reduced tendency to allow fluids to pass back through
and rewet the wearer's skin. Thus, the surface of the formed film which is in
contact with the body remains dry, thereby reducing body soiling and
creating a more comfortable feel for the wearer. Suitable formed films are
described in U.S. Patent No. 3,929,135 issued to Thompson, on December
30, 1975; U.S. Patent No. 4,324,246 issued to Mulfane et al., on April 13,
1982; U.S. Patent No. 4,342,314 issued to Radel, et al., on August 3, 1982;
U.S. Patent No. 4,463,045, issued to Ahr, et al., on July 31, 1984 and U.S.
Pat . No. 5,006,394 issued to Baird, on April 9, 1991. Each of these patents
are incorporated herein by reference. The preferred topsheet for the
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primary absorbent member of the present invention is a formed film
described in one or more of the above patents and marketed on sanitary
napkins by The Procter 8~ Gamble Company of Cincinnati, Ohio as "DRI-
WEAVE".
The body or exposed surface of the formed film topsheet may be
hydrophilic so as to help fluid transfer through the topsheet faster than if
the
body surface was not hydrophilic so as to diminish the likelihood that
menstrual fluid will flow off the topsheet rather than flowing into and being
absorbed by the absorbent core. In a preferred embodiment, surfactant may
be incorporated into the polymeric materials of the formed film topsheet
such as is described in PCT Publication No. W093/09741 published on May
23, 1993 in the name of Aziz, et al., which is incorporated herein by
reference. Alternatively, the body surface of the topsheet can be made
hydrophilic by treating it with a surfactant such as described in U.S. Patent
No. 4,950,264 issued to Osborn, on August 21, 1990 and which is
incorporated herein by reference.
In a preferred embodiment of the present invention, as shown in FIG.
4, the topsheet 32 may comprises a nonwoven 37 and a formed film 36
superposed on the nonwoven 37. The formed film 36 has a first surface 38
facing outwardly, ~a second surface 39 facing the nonwoven 37 and the
absorbent core 34, and apertures 42 extending from the first surface 38 to
the second surface 39. The area of the apertures 42 in the second surface
39 adjacent to the absorbent core 34 is generally smaller than the area of
the apertures 42 in the first surtace 38. Because the aperture area of the
first surface 38 is generally greater than the aperture area of the second
surtace 39, fluid can easily penetrate the topsheet 32 toward the absorbent
core 34. However, it inhibits fluid acquired in the absorbent core 34 from
transferring from the absorbent core 34 toward the outside and from
rewetting the wearer's skin. The nonwoven 37 is superposed to the second
surface 39 of the formed film. The formed film 36 and the nonwoven 37
each has rectangular shape when the formed film 36 and the nonwoven 37
are unfolded as shown in FIG. 5. The topsheet 32 has longitudinal sides 45
and transverse ends 46. The formed film 36 has corresponding longitudinal
sides 43 and transverse ends 44 and the nonwoven 37 has corresponding
longitudinal sides 47 and the transverse ends 48. The formed film 36 and
the nonwoven 37 may be superposed by any suitable manner. Preferably,
the formed film 36 and the nonwoven 37 may be joined to one another along
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the longitudinal sides 45 by a plurality of discrete dots 49. The discrete
dots
may be formed by applying pressure, heat, pressure and heat, and/or
adhesive. Alternatively, the formed film 36 and the nonwoven 37 may be
joined to one another along the entire length of the longitudinal sides 45.
The absorbent core 34 may be any absorbent means which is
generally compressible, conformable, resilient, non-irritating to the wearer's
skin and capable of absorbing and containing body exudates. The
absorbent core 34 may be manufactured from a wide variety of fluid
absorbent materials commonly used in disposable sanitary napkins, and
other disposable absorbent articles. Examples of suitable absorbent
materials include comminuted wood pulp (which is generally referred to as
airfelt), creped cellulose wadding, modified cross-linked cellulose fibers
(such as those described in U.S. Patent No. 5,217,445 issued to Young, et
al., on June 8, 1993), capillary channel fibers (that is, fibers having intra-
fiber
capillary channels such as those described in U.S. Patent No. 5,200,248
issued to Thompson, et al., on April 6, 1993), absorbent foams {such as
those described in U.S. Patent No. 5,260,345 issued to DesMarais, et al., on
November 9, 1993 and U.S. Patent No. 5,268,244 issued to DesMarais, et
al., on December 7, 1993), thermally bonded airlay materials (such as those
material described in U.S. Patent No. 5,607,414 issued to Richards, et al.,
on March 4, 1997), hydrogel-forming polymer gelling agents (such as those
material described in U.S. Patent No. 4,673,402 issued to Weisman, et al.,
on June 16, 1987 and U.S. Patent No. 4,935,022 issued to Lash et al., on
June 19, 1990), absorbent sponges, synthetic staple fibers, polymeric fibers,
peat moss, or any equivalent materials or combinations of materials.
Suitable absorbent cores comprising foams are described in U.S. Patent No.
5,260,345 issued to DesMarais, et al., on Nov. 9, 1993; U.S. Patent No.
5,147,345 issued to Young, et al., on Sep. 15, 1992; U.S. Pat No.
5,1949,720 issued to DesMarais, et al., on Sep. 22, 1992; U.S. Patent No.
5,198,472 issued DesMarais, et al., on Mar 30, 1993 and U.S. Patent No.
5,250,576 issued DesMarais, et al., on Oct. 5, 1993. Additional cores
comprising foams are described in European Application 0 293 208 B1.
Absorbent cores comprising sponges are described in U.S. Patent Nos.
3,512,530 and 3,954,493 and French Patent 2,203, 827.
Materials selected for use as the absorbent core 34 are preferably
compliant, soft, comfortable, compressible and resilient to enhance body fit
and comfort of the primary absorbent member 30. Preferably, the absorbent
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core 34 is compressible such that the primary absorbent member 30 will
deform under relatively small forces that are experienced during normal use.
In addition to being compressible, the materials comprising the absorbent
. core 34 are preferably conformable such that the primary absorbent member
30 is able to provide improved fit into and around the labia and perineum.
While being generally compressible and conformable under relatively small
forces, those forces exerted by the external female genitalia during use, it
is
also important that the primary absorbent member 30 be sufficiently resilient
such that when subjected to normal wearing forces it does not permanently
collapse. Preferably, the primary absorbent member 30 will be sufficiently
resilient that it will conform to the contours of the body to provide intimate
contact with the exposed genitalia of the female use. Intimate contact with
the exposed female genitalia helps provide better fluid transfer from the user
into the primary absorbent member without allowing fluid to bypass and/or
run-off the primary absorbent member. While the resilient characteristics of
the absorbent core 34 allow for improved fit, they must be balanced against
the need for the product to be both soft and comfortable for the wearer.
In a preferred embodiment of the present invention, the absorbent
core 34 comprises hydrogel-forming polymers and hydrophilic fibers such as
airfelt. Preferably, the absorbent core 34 comprises hydroge!-forming
polymers of between 10 % and 60 %. More preferably, the absorbent core
34 comprises hydrogel-forming polymers of between 15 % and 50 %. The
absorbent core 34 may includes airfelt of between 40 % and 90 %.
Preferably, the absorbent core 34 may includes airfelt of between 50 % and
85 %. It necessary, the absorbent core 34 may further include hydrophobic
fibers. As shown in FIG. 3, the absorbent core 34 is manufactured in a
generally cylindrical shape to provide the primary absorbent member 30 with
a generally cylindrical shape. While the absorbent core 34 shown in FIG. 3
has a generally circular cross-section, the absorbent core may be
manufactured in a wide variety of shapes such as rectangular, triangular,
oval, square, pentagonal, U-shaped, Z-folded, etc.
The topsheet 32 may encircle the absorbent core 34 as shown in
FIGS. 2 and 3. The topsheet 32 has longer length and wider width than the
absorbent core 34 (shown in FIG. 5). The transverse width of the topsheet
32 is more than twice of the transverse width of the absorbent core 34. This
allows the longitudinal sides 45 of the topsheet 32 to overlap underneath the
absorbent core 34 to encircle the absorbent core 34 as shown in FIG. 3.
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The longitudinal sides 45 of the topsheet 32 may be secured by any suitable
manner to keep the encircled shape. Suitable manners include, but are not
limited to adhesives such as line adhesive, spiral adhesive, or spot
adhesive. In a preferred embodiment shown in FIGS. 3 and 5, tine adhesive
51 is applied to one of the longitudinal sides 45 of the topsheet 32 along the
entire length of the longitudinal length. Alternatively, intermittent line
adhesive may be applied along the entire length of the longitudinal length.
The topsheet 32 may be associated with the absorbent core 34 in any
suitable manner. Suitable manners include, but are not limited to
associating the topsheet 32 with the absorbent core 34 with adhesives such
as by spray adhesive, line adhesives or spot adhesive between the topsheet
32 and the absorbent core 34. Alternatively, or additionally, the topsheet 32
may be associated with the absorbent core 34 by entangling the fibers of the
absorbent core 34 with the topsheet 32, by fusing the topsheet 32 to the
absorbent core 34 with a plurality of discrete individual fusion bonds, or by
any means known in the art. To insure proper fluid transfer between the
topsheet 32 and the absorbent core 34, it is preferred that the topsheet 32
be substantially continuously secured to the underlying absorbent core 34
throughout their common association or interface. By substantially
continuously securing the topsheet 32 to the underlying absorbent core 34,
the topsheet 32 will have a reduced tendency to separate from the
absorbent core 34 during use. Separation of the absorbent core from the
topsheet 32 may inhibit fluid transfer from the topsheet 32 into the
underlying absorbent core 34. Therefore, the body-facing side of the
absorbent core 34 may be secured to the topsheet 32 by, i.e., adhesive
while the body-facing side of the absorbent core 34 may not be secured to
the topsheet 32 so as to delay fluid transfer from the absorbent core 34 into
the secondary absorbent member 50.
The primary absorbent member 30 is preferably circular or oval in
cross-section while the primary absorbent member 30 can be generally of
any cross-sectional shape in its unstressed condition. The length PL, the
width PW and the thickness PT of the primary absorbent member 30 can be
of any convenient dimension. The length PL is preferably from about 2 to 35
cm, more preferably from about 10 to 35 cm, and most preferably from
about 20 to 35 cm. Preferably, the length PL of the primary absorbent
member 30 may be generally equal to the length SL of the secondary
absorbent member 50. The width PW is preferably from about 0.5 to 5 cm,
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more preferably from about 1 to about 5 cm, and most preferably from about
2 to about 4 cm. The width PW of the primary absorbent member 30 may
be less than the width SW of the secondary absorbent member 50. The
thickness PT is preferably from about 0.2 to 2.0 cm, more preferably from
about 0.2 to 1.5 cm, and most preferably from about 0.4 to 1.2 cm.
Preferably, the thickness PT of the primary absorbent member. 30 may be
greater than the thickness ST of the secondary absorbent member 50. A
ratio of the thickness PT to the width PW, or the ratio (PT/PW) may be
between 0.05 and 1.5. Preferably, the ratio may be between 0.08 and 1.00.
More preferably, the ratio may be between 0.08 and 0.5.
The caliper of the primary absorbent member 30 is determined by the
following test. A comparator gauge, and specifically the Peacock Gage
Model No. 307, available from 4zaki Manufacturing Co., LTD. is needed.
The comparator gauge should have a circular comparator foot made of
aluminum and having a weight of 9.0 grams and a contact surface of 16
square centimeters. The comparator gauge is zeroed. An 60.0 grams
stainless steel weight is placed on the spindle extending above the
comparator dial. The comparator foot is raised and the primary absorbent
member and the primary absorbent member is placed garment surface
down on the base plate. The primary absorbent member is positioned on
the base plate so that when the foot is lowered it is in the region of the
primary absorbent member for which the measurement is desired. Try to
smooth out or avoid any wrinkled in the primary absorbent member. Gently
lower the foot onto the primary absorbent member. Determine the primary
absorbent member caliper by reading the comparator dial 5 to 10 seconds
after the foot comes in contact with the primary absorbent member.
The primary absorbent member 30 of the present invention is
preferably relatively conformable. It is preferred to keep the primary
absorbent member relatively conformable so that it will readily fit into the
labial grove during use. It has been found that a primary absorbent member
having the width and/or thickness is able to comfortably fit next to the
labial
area. While primary absorbent members have been described above as
having width or thickness greater than the above width or thickness, they too
may fit within the labial groove if they are sufficiently conformable. It is
not
necessary that all of the primary absorbent member fit w'tthin the labial
groove, however, a portion of the primary absorbent member is preferably
capable of fitting within the labial groove.
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The primary absorbent member 30 may include optional elements.
The primary absorbent member 30 may optionally comprise a resilient .
member with the absorbent core 34. The resilient member may comprise a
single member or a plurality of individual members. Suitable materials which
may be used as the resilient member include, but are not limited to, nylon,
polypropylene, polyurethane, polyethylene, polyesterm synthetic rubber, and
other synthetic materials such as formed films, or natural materials such as
rubber, sponges, and the like or any suitable material which is capable of
resisting collapse under normal wearing conditions of sanitary napkins
during use. The resilient member may be manufactured in a wide variety of
shapes such as rectangular, triangular, oval, square, pentagonal, U-shaped,
Z-folded, etc. The resilient member may extend throughout the entire length
of the primary absorbent member 30. The resilient member may only
extend through a portion of the length of the primary absorbent member 30.
The resilient member may be positioned within the frrst end region 27, the
central region 28, the second end region 29 or any combination of the
above. For example, the resilient member may be positioned in either the
first end region 27 or the second end region 29 of the primary absorbent
member, in both the first end region 27 and the second end region 29 of the
primary absorbent member 30, in the central region 28 of the primary
absorbent member, or in the central region 28 and the end regions 27, 29 of
the primary absorbent member 30.
Optionally, the primary absorbent member 30 may comprise an
acquisition layer positioned between the topsheet 32 and the absorbent core
34. The acquisition layer may serve several functions including improving
wicking of exudates over and into the absorbent core 34. By improving the
wicking of exudates, the acquisition layer provides a more even distribution
of the exudates throughout the absorbent core. The acquisition layer may
be comprised of several different materials including nonwoven or woven
webs of synthetic fibers including polyester, polypropylene, or polyethylene;
natural fibers including cotton or cellulose; blends of such fibers; or any
equivalent materials or combinations of materials. Examples of sanitary
napkins having an acquisition layer and a topsheet are more fully described
in U.S. Patent No. 4,950,264 issued to Osborn and PCT Publication No.
W093/11725 published, on Jun. 24, 1993 in the names of Cree, et al. Each
of these references are incorporated herein by reference. In a preferred
embodiment, the acquisition layer may be joined with the topsheet by any of
i
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the conventional means for joining webs together, most preferably by fusion
bonds as is more fully described in the above-referenced Cree application.
Referring to FIGS. 1-3A, the second necessary constituent of the
compound sanitary napkin 20 of the present invention is the secondary
absorbent member (base member) 50. The secondary absorbent member
50 has generally rectangular shape extending in the longitudinal direction
along the longitudinal centerline L. In a preferred embodiment, the
longitudinal length SL may be generally equal to the longitudinal length PL
of the primary absorbent member 30. The transverse width SW may be
generally broader than the transverse width PW of the primary absorbent
member 30. The secondary absorbent member 50 has the longitudinal
sides 21 and the transverse ends 22. In a preferred embodiment shown in
FIG. 1, a pair of flaps 33 extends outwardly from the longitudinal sides 21 in
the central region 28. The secondary absorbent member 50 preferably
comprises a fluid pervious body-facing sheet or fluid pervious topsheet 52, a
fluid impervious garment-facing sheet or fluid impervious backsheet 54
joined with the topsheet 52, and a secondary absorbent element 56
positioned between the topsheet 52 and the backsheet 54.
The topsheet 52 can be any fluid pervious material commonly used in
sanitary napkins, disposable diapers, and the like. It can be any of the
materials described above as being useful in the topsheet 32 of the primary
absorbent member 30. A preferred topsheet 52 comprises an apertured
formed film. Apertured formed films are preferred for the topsheet because
they are pervious to body exudates and yet non-absorbent and have a
reduced tendency to allow fluids to pass back through and re-wet the
wearer's skin. Thus, the surface of the formed film which is in contact with
the body remains dry, thereby reducing body soiling and creating a more
comfortable feel for the wearer. Suitable formed films are described in U.S.
Patent No. 3.929,135 issued to Thompson, on December 30, 1975; U.S.
Patent No. 4,324,246 issued to Mullane, et al., on April 13, 1982; U.S.
Patent No. 4,342,314, issued to Radel, et al., on August 3, 1982; U.S.
Patent No. 4,463,045 issued to Ahr, et al., on July 31, 1984 and U.S. Patent
. No. 5,006,394 issued to Baird, on April 9, 1991. Each of these patents are
incorporated herein by reference. The preferred topsheet for the primary
absorbent member of the present invention is a formed film described in one
or more of the above patents and marketed on sanitary napkins by The
Procter & Gamble Company of Cincinnati, Ohio as "DRI-WEAVE".
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The absorbent element 56 can be any absorbent material commonly
used in sanitary napkins, disposable diapers and the like. It can be any of
the materials described above as being useful in the absorbent core 34 of
the primary absorbent member 30. As a practical matter, most of the bodily ,
fluids are absorbed by and are contained within the absorbent core 34 of the
primary absorbent member 30. One major function of the secondary
absorbent member 50 is to protect the user's garments from soiling by
absorbed fluids which may be expelled from the primary absorbent member
30 or which may inadvertently bypass the primary absorbent member 30.
The overall absorptive capacity of the absorbent element 56 may be,
therefore, somewhat less than that of the absorbent core 34. Because the
absorbent core 34 is preferably intended to absorb most or substantially all
of the bodily fluids during use, its absorptive capacity will be somewhat if
not
significantly greater than that of the absorbent element 56. Because the
absorbent element 56 of the secondary absorbent member 50 performs a
different function from that of the absorbent core 34, the absorbent element
56 can be, and most preferably is, somewhat thinner and less bulky than the
absorbent core 34.
Because the absorbent element 56 has different requirements than
does the absorbent core 34, it can be formed of different materials. For
example, single or multiple plies of paper tissue as commonly used in paper
toweling or toilet tissue can be used to form the absorbent element 56.
Preferably, the absorbent element 56 is formed of from about 1 to about 5
plies of paper tissue. Paper tissue comprising one or more plies having a
basis weight of from about 24 to about 48 grams per square meter and an
apparent density of from about 0.10 to about 0.12 grams per cubic
centimeter as made by the process described in U.S. Patent No. 3,301,746
issued to Sanford and Sisson, on Jan. 31, 1967 and which patent is hereby
incorporated herein by reference has been found to be quite satisfactory for
use as the absorbent element 56. Wet strength resins and latex binders can
be, and preferably are, used to provide additional strength to the paper
tissue used in the absorbent element. Paper tissue made by the process
described in U.S. Patent No. 3,994,77'1 issued to Morgan et al., on Nov. 30,
1976, and which patent is hereby incorporated herein by reference, can also
be used to good advantage as the absorbent element 56.
The absorbent element 56 may have any suitable shape including,
but are not limited to, oval, hourglass, dog-bone, asymmetric, etc. In a
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preferred embodiment shown in FIG. 1, the absorbent element 56 has
generally rectangle shape encompassed by longitudinal sides 55 and
transverse edges 57. The absorbent element 56 also has a longitudinal
length CL, a transverse width CW and a thickness CT. The longitudinal
a
length CL may be shorter than the longitudinal length PL and SL. The
length CL may be from about 10 to about 33 cm, preferably from about 15 to
about 33 cm. The transverse width CW may be wider than the transverse
width PW of the primary absorbent member 30 at least in the central region
28 (i.e., the crotch region corresponding to the crotch region of the
undergarment when the compound sanitary napkin is used). More
preferably, the transverse width CW may be wider than the transverse width
PW of the primary absorbent member 30 throughout the entire length. The
width CW may be from about 3 to about 12 cm, preferably from about 4 to
about 10 cm, more preferably from about 5 to about 8 cm. FIGS. 10 and 11
show alternative shape of the compound sanitary napkin and the secondary
absorbent element. The compound sanitary napkin 90 shown in FIG. 10
has a narrowest portion (i.e., the crotch region) at the center in the
longitudinal direction, and does not have flaps on both longitudinal sides.
The secondary absorbent member 95 of the compound sanitary napkin 90
may have a patch type absorbent element 91 positioned generally in the
crotch region as shown in FIG. 10. The patch type absorbent element 91
may have an oval shape which has the widest portion at the center in the
longitudinal direction. The widest portion of the absorbent element 91
preferably may coincide with the narrowest crotch region of the compound
sanitary napkin 90. The compound sanitary napkin 92 shown in FIG. 11 has
back flaps 94 in addition to the flaps 33 positioned on the crotch region. The
secondary absorbent member 96 of the compound sanitary napkin 92
shown in FIG. 11 may have a shaped absorbent element 93 having the
narrowest portion in the crotch region of the compound sanitary napkin 92.
The narrowest portion of the shaped absorbent element 93 preferably may
coincide with the crotch region of the compound sanitary napkin 92. In both
embodiment, the transverse width CW is preferably wider than the
transverse width PW of the primary absorbent member 30 in the crotch
region of the compound sanitary napkin. Preferably, the width PW may be
less than about 80 % of the width CW. More preferably, the width PW may
be less than about 70 % of the width CW.
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The backsheet 54 is impervious to fluids (e.g., menses and/or urine)
and is preferably manufactured from a thin plastic film, although other .
flexible fluid impervious materials may also be used. As used herein, the
term "flexible" refers to materials which are compliant and will readily
conform to the general shape and contours of the human body. In use, the
backsheet 54 is interposed between the absorbent element 56 and the
user's undergarments. The function of the backsheet 54 is to prevent
exudates which may be expelled from or which inadvertently bypass the
primary absorbent element 30 and exudates absorbed and contained in the
absorbent element 56 from contacting and soiling the user's undergarments.
The backsheet 54 may thus comprise a woven or nonwoven material,
polymeric films such as thermoplastic films of polyethylene or polypropylene,
or composite materials such as a film-coated nonwoven material.
Preferably, the backsheet is a polyethylene film having a thickness of from
about 0.012 mm(0.5 mil) to about 0.015 mm (2.0 mil). Exemplary
polyethylene films are manufactured by Clopay Corporation of Cincinnati,
Ohio under the designation P18-0401 and by Ethyl Corporation, Visqueen
Division, of Terre Haute, Indiana, under the designation XP-39385. The
backsheet is preferably embossed andlor matte finished to provide a more
cloth like appearance. Further, the backsheet may permit vapors to escape
from the absorbent element 56 (i.e., breathable) while still preventing
exudates from passing through the backsheet 54.
The shape of the secondary absorbent member 50 can be of
generally rectangular encompassed by the longitudinal sides 21 and the
transverse ends 22. Other suitable shapes include but are not limited to
oval, hourglass, dog-bone, asymmetric, etc. The secondary absorbent
member 50 may have flaps 33 each of which are adjacent to and extend
laterally from the longitudinal sides 21 of the secondary absorbent member
50 in the central region 28 as shown in FIG. 1. The flaps 33 are configured
to drape over the edges of the wearer's panties in the crotch region so that
the flaps are disposed between the edges of the wearer's panties and the
wearer's thighs. The flaps 33 serve at least two purposes. First, the flaps
33 help serve to prevent soiling of the wearer's body and panties by
menstrual fluid, preferably by forming a double wall barrier along the edges
of the panty. Second, the flaps 33 are preferably provided with attachment
means, as described hereinafter, on their garment facing surface so that the
flaps 33 can be folded back under the panty and attached to the garment
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facing side of the panty. In this way, the flaps 33 serve to keep the sanitary
napkin 20 properly positioned in the panty.
In a preferred embodiment, the flaps 33 are comprised of a topsheet
and a backsheet. Further, the flaps 33 are preferably unitary to the laminae
of the secondary absorbent element 50. In other words, the topsheet 52 of
the secondary absorbent member 50 and the backsheet 54 of the secondary
absorbent member may simply extend laterally outward from the longitudinal
sides 21 to form the flaps 33. However, the flaps 33 need not be unitary
with the secondary absorbent member 50, but can be separate elements
which are affixed to the secondary absorbent member 50. Further, the flaps
33 can be comprised of a single substrate or other laminae configurations.
It is preferable, however, that the flaps 33 have a fluid impervious backsheet
to prevent exudates which reach the flaps from soiling the edges of the
wearer's panties.
Further, it is preferable that the flaps 33 may be provided with an
absorbent member, at least to a point beyond the edges of the wearer's
panties. Theoretically, only a relatively small amount of menses should
reach the flaps 33, therefore, only a relatively small amount of absorbent
material is desirable in the flaps. However, the flaps 33 preferably have at
least some absorbent material in order to prevent any exudates that reach
the flaps 33 from being able to flow further to unprotected areas. The
absorbent material may be a tissue, or an extension of the absorbent
element 56. Preferably, the absorbent material in the flaps 33 is relatively
highly flexible.
A number of sanitary napkins having flaps suitable or adaptable for
use with the secondary absorbent member 50 of the compound sanitary
napkin 20 of the present invention are disclosed in U.S. Patent No.
4,687,478 issued to Van Tilburg, on Aug. 18, 1987; U.S. Patent No.
4,589,876 issued to Van Tilburg, on may 20, 1986; and U.S. Patent No.
4,608,047 issued to Mattingly, on Aug. 26, 1986. Each of these patents are
incorporated herein by reference. Optionally, the secondary absorbent
member 50 may comprise components that naturally wrap the sides of a
wearer's panties. A sanitary napkin having components that naturally wrap
the sides of a wearer's panties suitable for use with the secondary absorbent
member 50 of the compound sanitary napkin 20 of the present invention are
disclosed in U.S. Patent No. 5,584,829 issued to Lavash et al., on Dec. 17,
1996 and U.S. Patent No. 5,558,663 issued to Weinberger et al., on Sep.
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18
24, 1996. The disclosures of the preceding publications are incorporated
herein by reference.
Preferably, the secondary absorbent member 50 is provided with a
support means or attachment means, such as adhesive attachment means
58 and 62. The adhesive attachment means 58 provides a means for
securing the compound sanitary napkin 20 in the crotch portion of the user's
undergam~ent or panty. The adhesive attachment means 62 provides a
means for securing the flaps 33 of the compound sanitary napkin 20 to the
garment facing side of the panty so that the flaps 33 can be folded back
under the panty. Thus, a portion or all of the outer or garment surface of the
backsheet 54 may coated with adhesive. In a preferred embodiment, at
least a portion of the adhesive 58 may be positioned on the garment surface
of the backsheet 54 along the longitudinal direction of the secondary
absorbent member 50 and may have, but not limited to, a line-shape along
the longitudinal direction. The adhesive 62 may be positioned on the
garment surface of the backsheet 54 of the flaps 33 and may have, but not
limited to, a rectangle-shape. Any adhesive or glue used in the art for such
purposes can be used for the adhesive herein, with pressure-sensitive
adhesives being preferred. Suitable adhesives are Century A-305-IV
manufactured by the Century Adhesives Corporation of Columbus, Ohio,
and Instant Lock 34-2823 manufactured by the National Starch and
Chemical Company of Bridgewater, NJ. Suitable adhesive fasteners are
also described in U.S. Patent No. 4,917,697.
The pressure-sensitive adhesive is typically covered with a removable
release liners 59 and 63 in order to keep the adhesive from drying out or
adhering to a surface other than the crotch portion of the panty prior to use.
Suitable release liners are also described in the above referenced U.S.
Patent No. 4,917,697. Any commercially available release liners commonly
used for such purposed can be utilized herein. Non-limiting examples of
suitable release liners are BL30MG-A Silox E1/0 and BL30MG-A Silox 4P/0
both of which are manufactured by the Akrosil Corporation of Menasha, WI.
The compound sanitary napkin 20 of the present invention is used by
removing the release liner 59 and 63 and thereafter placing the sanitary
napkin 20 in a panty so that the adhesive 58 and the adhesive 62 contacts
the panty. The adhesives 58 and 62 maintains the sanitary napkin in its
position within the panty during use.
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The topsheet 52 and the backsheet 54 of the secondary absorbent
member 50 may be joined to one another by any suitable manner. The
topsheet 52 may be joined to the backsheet 54 along the periphery 64 or
may be joined to the backsheet in all the region excluding the region where
the absorbent element 56 exists. In the region where the absorbent element
56 exists, the topsheet 52 and the backsheet 54 each may be joined to the
absorbent element 56. Suitable manners include, but are not limited to
applying pressure, heat, heat and pressure, or adhesives such as line
adhesive, spiral adhesive, or spot adhesive. In a preferred embodiment
shown in FIG. 1, the topsheet 52 and the backsheet 54 may be joined by
applying heat along the periphery 64 of the sanitary napkin 20.
The length SL, the width SW and the thickness ST of the secondary
absorbent member 50 can be of any convenient dimension. The length SL
is preferably from about 5 to 35 cm, more preferably from about 10 to 35 cm,
and most preferably from about 20 to 35 cm. Preferably, the length SL of
the secondary absorbent member 50 may be generally equal to the length
PL of the primary absorbent member 30. The width SW is preferably from
about 4 to 13 cm, more preferably from about 5 to about 11 cm, and most
preferably from about 6 to about 9 cm. The secondary absorbent member
50 of the present invention is preferably relatively thin and flexible. The
thickness ST is preferably from about 0.1 to 2.0 cm, more preferably from
about 0.1 to 1.0 cm, and most preferably from about 0.1 to 0.4 cm.
Preferably, the thickness ST of the secondary absorbent member 50 may be
less than the thickness PT of the primary absorbent member 30.
The secondary absorbent member (base member) 50 optionally may
be manufactured without an absorbent element 56. Since most if not all of
the bodily fluids are preferably absorbed by and are contained within the
absorbent core 34 of the primary absorbent member 30, the base member
50 need only to protect the user's garments from soiling by relatively small
amounts of fluids which may be expelled from the primary absorbent
. member 30 or which may inadvertently bypass the primary absorbent
member 30. Accordingly, since the expected amounts of fluids which may
. come into contact with the base member are relatively small, an base
element may not be necessary to contain the fluids within the base member
50 and prevent them from soiling the user's garments.
To form the compound sanitary napkin 20 of the present invention,
the primary absorbent member 30-and the secondary absorbent member 50
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are joined by union means generally indicated as 70 in FIGS. 1 - 3, 6 and 7.
The union means 70 serves to join the primary absorbent member 30 and
the secondary absorbent member 50 into the compound sanitary napkin 20
of the present invention with sufficient tenacity that the primary absorbent
member 30 and the secondary absorbent member 50 are not disconnected
during use. Any suitable union means such as adhesive attachment,
pressure attachment, heat attachment, or ultrasonic attachment can be
used. The primary absorbent member 30 may be affixed to said secondary
absorbent member 50 by the union means 70 along the entire common
length. Alternatively, the primary absorbent member 30 may be affixed to
said secondary absorbent member 50 intermittently along the common
length.
In a preferred embodiment shown in FIGS. 1 - 3, 6 and 7, the primary
absorbent member 30 is affixed to the secondary absorbent member 50 by
the union means 70 including a first union means 72 and the second union
means 74.
The first union means 72 includes applying pressure to the
overlapped transverse ends 22 and 25 in plurality of discrete dots. By
applying pressure at the overlapped transverse ends 22 and 25, the
topsheet 32 of the primary absorbent member 30, the topsheet 52 and the
backsheet 54 of the secondary absorbent member 50 are affixed to each
other at the overlapped transverse ends 22 and 25. Alternatively, the first
union means 72 can include applying heat in a plurality of discrete dots,
lines or area. While applying heat works well to join mullet-layers, heat
transfer between the layers to join the layers may become worse as the
layers becomes thick. In the preferred embodiment shown in FIG. 2, since
the longitudinal sides 45 of the topsheet 32 of the primary absorbent
member 30 are overlapped to one another underneath the absorbent core
34, five layers comprising three layers of topsheet 32, one layer of the
topsheet 52 and one layer of the backsheet 54 are joined. If the topsheet 32
comprises two layers having the formed film 36 and the nonwoven 37, eight
layers must be joined to each other as shown in FiG. 7. As the layers
becomes thick, it becomes preferable to apply pressure, or pressure and _
heat to join the layers. Alternatively, the first union means 72 may include
applying adhesive between the layers, or applying combination of pressure,
heat, and adhesive. In the preferred embodiment, adhesive 72A may be
applied to the inside surface of the topsheet 32 at the transverse end 46 as
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shown in FIGS. 2, 5 and 7. Alternatively, adhesive 72B may be applied
between the formed film 3fi and the nonwoven 37 at the transverse ends 44
and 48 as shown in FIG. 7. Alternatively, both the adhesive 72A and the
adhesive 72B may be applied.
The second union means 74 includes applying adhesive such as
spiral adhesive, line adhesive, or spot adhesive between the primary
absorbent member 30 and the secondary absorbent member 50. As shown
in FIG. 6, in a preferred embodiment, spiral adhesive 74 as the second
union means is applied continuously between the primary absorbent
member 30 and the secondary absorbent member 50. When the primary
absorbent member 30 and the secondary absorbent member 50 are desired
to affix to one another along the entire common length, it is preferable to
use
spiral adhesive since applying spiral adhesive prevents the absorbent
member 30 and 50 from affixing intermittently. The primary absorbent
member 30 and the secondary absorbent member 50 are preferably affixed
at the narrower width AW than the transverse width PW of the primary
absorbent member 30. Preferably, the width AW may be less than 70 % of
the width PW. This allows the primary absorbent member 30 to conform
with the female body shape and movement of the female body.
The compound sanitary napkin 20 may include a variety of
alternatives and/or options. The primary absorbent member 30 can
comprise a fluid barrier 35 as shown in FIG. 8. The fluid barrier 35 may
position on the half bottom side of the absorbent core 34 to inhibit fluid
from
transferring the absorbent core toward the secondary absorbent member 50.
The fluid barrier 35 tends to contain absorbed fluids within the absorbent
core 34 and can be constructed from materials having the same properties
as the fluid impervious backsheet on the secondary absorbent member 50
described hereinafter. The fluid barrier 35 may extend along the entire
length of the primary absorbent member 30 or may extend only in the
central region 28 of the primary absorbent member 30, or in the first end
. region 27 and the second end region 29.
Alternatively, the topsheet 32 of the primary absorbent member 30
. may comprise a sheet having a fluid pervious zone 76 and fluid impervious
zone 78. When the topsheet 32 comprises a formed film, the fluid pervious
zone 76 may be apertured zone and the fluid impervious zone 78 may be
non-apertured zone. As shown in FIG. 9, the fluid pervious zone 76 of the
topsheet 32 may position on the half bottom side of the absorbent core 34 to
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inhibit fluid from transferring the absorbent core toward the secondary
absorbent member 50. The fluid pervious zone 76 tends to contain
absorbed fluids within the absorbent core 34.
The compound sanitary napkin 20 may be extensible. The individual
components of the primary absorbent member 30 and the secondary
absorbent member 50 may be comprised of components that are extensible
(preferably, capable of stretching) particularly in the longitudinal direction
when the compound sanitary napkin 20 is worn. Preferably, the compound
sanitary napkin 20 is capable of elongating in the longitudinal direction
between about 15 % and about 40% of its unstretched length. This
extensibility provide better in-use fit, comfort, and decreased staining when
the compound sanitary napkin is affixed to the wearer's undergarments.
Preferably, the secondary absorbent member 50 is comprised of
components that are also extensible in the lateral direction when the
compound sanitary napkin 20 is worn. Preferably, the compound sanitary
napkin 20 is capable of elongating in the lateral direction between about
15% and about 40% of its unstretched length. The topsheet 32 for both the
primary absorbent member 30 and the secondary absorbent member 50
may comprise an elastic, three-dimensional, fluid pervious, polymeric web
as disclosed in U.S. Patent No. 5,366,782 issued to Curro et al., on Nov. 22,
1994 and which is incorporated herein by reference. A particularly preferred
extensible backsheet is an extended adhesive film known as Formula #198-
388 manufactured by the Findley Adhesives Company of Wauwatosa,
Wisconsin. Sanitary napkins having extensible components are described
in U.S. Pat No. 5,611,790 issued to Osborn, et al., on Mar. 18, 1997 and
PCT Publication No. W093/01786 published Feb. 4, 1993 in the names of
Osborn, et al. The disclosures of the preceding publications are
incorporated herein by reference.
The compound sanitary napkin 20 can conform with the female body.
Because the primary absorbent member 30 is preferably sized and shaped
such that it will fit next to the labia area, the primary absorbent member 30
.
will reside at least partially within the labia. As shown in FIG. 10, when the
compound sanitary napkin 20 is worn by female and supported by a
undergarment 82, a portion of the primary absorbent member 30 will
preferably fit next to the labia area during use. In contrast, one major
function of the secondary absorbent member 50 is to protect the user's
garments from soiling by absorbed fluids which may be expelled from the
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primary absorbent member 30 or which may inadvertently bypass the
primary absorbent member 30. The secondary absorbent member 50 is
preferably remote from the body such that the secondary absorbent member
50 does not touch the body. The shape of the primary absorbent member
30 is sized and shaped to be remote the secondary absorbent member 50
from the body and to ensure space 80 between the body and the secondary
absorbent member 50. This allows the longitudinal sides of the secondary
absorbent member 50 to remain white.
The compound sanitary napkin 20 can absorb body fluids. The total
absorbent capacity of the primary absorbent member 30 should be
compatible with the intended exudate loading for the compound sanitary
napkin 20. Further, the absorbent capacity of the absorbent core 30 may be
varied to accommodate wearers ranging in the expected amount of exudate
fluid. Typically, exudate fluid of between 2 and 20 grams is expected during
a normal period of wearing a sanitary napkin. When the compound sanitary
napkin 20 is exposed to such fluid loading of between 2 and 20 grams, the
primary absorbent member 30 can absorb 80 % of the fluid of between 2
and 20 grams in an actual wear situation. Further, when the compound
sanitary napkin 20 is exposed to fluid loading of between 20 and 30 grams
exceeding the normal amount, the primary absorbent member 30 can
absorb 70 % of the fluid of between 20 and 30 grams. Because the primary
absorbent member 30 has capacity of absorbing at least 70 % of loaded
fluid of between 2 and 30 grams when the sanitary napkin is applied to
female body and used, the primary absorbent member 30 having such
capacity allows the longitudinal sides of the secondary absorbent member
50 to remain white. This provides consumers with a visual signal that boosts
their confidence in the absorbency and leakage-proof performance of the
sanitary napkin product.
The primary absorbent member 30 preferably comprises hydrogel-
forming polymers to enhance absorbing capacity of the primary absorbent
member 30. The more hydrogel-forming polymers the primary absorbent
member 30 contains, the more absorbing capacity the primary absorbent
member 30 has. Because the hydrogel-forming polymers get swelled after
the polymers absorbing fluid, the primary absorbent member 30 expands in
the transverse and thickness direction. This expansion of the primary
absorbent member 30 gives more conformity and fitness between the
primary absorbent member 30 and the female body. However, too much
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24
hydrogel-forming polymers causes gel-blocking problems resulting in
diminishing absorbing ability. More importantly, too much hydrogel-forming
polymers, when absorbing fluid, makes the primary absorbent member 30 a
straight cylindrical shape that won't bend easily without high bending force.
When this occurs, the primary absorbent member 30 may not fit the
curvature shape of female body because the transverse ends of the
compound sanitary napkin 20 tends to be remote from the body. Therefore,
appropriate amount of hydrogel-forming polymers is preferable from
standpoints of absorbing ability, conformity and fitness of the compound
sanitary napkin having the primary absorbent member.
It may be desirable to provide a compound sanitary napkin having a
primary absorbent member with varying degrees of width or caliper
throughout its length. For example, the primary absorbent member may be
relatively thicker in the central region as opposed to the end regions.
Alternatively, the primary absorbent member may be relatively thinner in the
central region as opposed to the end regions.
While particular embodiments of the present invention have been
illustrated and described, it would be obvious to those skilled in the art
that
various other changes and modifications can be made without departing
from the spirit and scope of the invention. It is therefore intended to cover
the appended claims all such changes and modifications that are within the
scope of this invention.
