Note: Descriptions are shown in the official language in which they were submitted.
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A METHOD FOR ASSEMBLING
BODY FITTING COMPOUND SANITARY NAPKIN
10
FIELD OF THE INVENTION
The present invention relates to a method for manufacturing disposable
sanitary
napkins. More particularly, the invention related to a method for
manufacturing 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 peiform 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
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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 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
a method
for manufacturing compound sanitary napkins in the manner of the present
invention.
Therefore, a primary object of the present invention is ~to provide a method
for
manufacturing compound sanitary napkins.
SUMMARY
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The present invention relates to a method of manufacturing a compound sanitary
napkin comprising a primary absorbent member and a base member. The primary
absorbent member extends in a longitudinal direction and comprises a primary
absorbent
element and a fluid pervious cover superimposed on the primary absorbent
element
having a body-facing side and a base member facing side. The primary absorbent
member superimposes on the base member such that the primary absorbent member
faces
a wearer's body when the compound sanitary napkin is used. The method
comprising the
steps of : providing the primary absorbent element onto the fluid pervious
cover such that
the body-facing side of the primary absorbent element faces the fluid pervious
cover and
such that the base member facing side of the primary absorbent element faces
generally
upward, wrapping the primary absorbent element by folding each of longitudinal
sides of
the fluid pervious cover toward the base member facing side of the primary
absorbent
element to make the primary absorbent member, forwarding the primary absorbent
member toward a combining section, feeding the base member toward the
combining
section to cover the primary absorbent member, and combining the primary
absorbent
member and the base member to make the compound sanitary napkin.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification 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 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
produced by the present invention;
FIG. 2 is a cross-sectional view taken along the longitudinal centerline L of
the
compound sanitary napkin shown in FIG. I;
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 produced by 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;
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FIG. 6 is a top plan view a compound sanitary napkin comprising 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 produced by the present invention;
FIG. 9 is a cross-sectional view of another embodiment of a compound sanitary
napkin produced by 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;
FIG. 13 is a schematic side elevational view of an exemplary process
embodiment
of the present invention;
FIG. 14 is a fragmentary, schematic side elevational view of the patterned
cylinder
of the joining unit shown in FIG. 13;
FIG. 15 is a fragmentary, schematic side elevational view of the patterned
cylinder
of the pressure applying unit shown in FIG. 13;
FIG. 16 is a first fragmentary plan view of the assembling process of the
sanitary
napkin produced by the process shown in FIG. 13;
FIG. 17 is a second fragmentary plan view of the assembling process of the
sanitary napkin produced by the process shown in FIG. 13;
FIG. 18 is a schematic side elevational view of another exemplary process
embodiment of the present invention;
FIG. 19 is a first fragmentary plan view of the assembling process of the
sanitary
napkin produced by the process shown in FIG. 18;
FIG. 20 is a second fragmentary plan view of the assembling process of the
sanitary napkin produced by the process shown in FIG. 18;
FIG. 21 is a schematic side elevational view of another exemplary process
embodiment of the present invention;
FIG. 22 is a first fragmentary plan view of the assembling process of the
sanitary
napkin produced by the process shown in FIG. 21;
FIG. 23 is a second fragmentary plan view of the assembling process of the
sanitary napkin produced by the process shown in FIG. 21.
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DETAILED DESCRIPT10N OF THE INVENTION
This invention is of a method for manufacturing a body fitting compound
sanitary
5 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 otherwise restored or
reused). The
term "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 majors, the
labia minors, the
clitoris, and the vestibule.
Before explaining the method, a preferred embodiment of a compound sanitary
napkin is described. Referring now to FIGS. 1 - 3, there is shown one
preferred
embodiment of a compound sanitary napkin 20. 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
lies 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
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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. l, preferably,
the
compound sanitary napkin 20 has flaps 33 extending from the 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 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. Aperiured
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 Mullane et
al., on
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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 primary absorbent member 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".
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, 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 surface
38. Because the aperture area of the first surface 38 is generally greater
than the aperture
area of the second surface 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 the longitudinal sides 45 by a
plurality
of discrete dots 49. The discrete dots rnay be formed by applying pressure,
heat, pressure
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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 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
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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, the absorbent core 34 comprises hydrogel-forming
polymers and hydrophilic fibers such as airfelt. Preferably, the absorbent
core 34
comprises hydrogel-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 care 34 may includes airfelt of between 50 % and $5 %. If 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 care 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. 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, line 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.
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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
5 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
10 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 ar 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 S cm, 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 S W 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 gieater than the
thickness ST
of the secondary absorbent member 50. A ratio of the thickness PT to the width
PW, or
the ratio (PTIPW) 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.
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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 Ozaki 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 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 within the labial groove, however, a portion of the
primary
absorbent member is preferably capable of fitting within the labial groove.
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 rnay
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.
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The resilient member may be positioned within the first 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
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 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.
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13
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 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".
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
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14
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. 3,994,771 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 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
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
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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
5 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.
The backsheet 54 is impervious to fluids (e.g., menses and/or urine) and is
10 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
15 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 undergan~nents. 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 and/or 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
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16
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 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 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 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
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17
issued to Weinberger et al., on Sep. 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 undergarment 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 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.
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
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18
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 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, the primary absorbent member 30 and
the secondary absorbent member 50 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
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
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19
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.
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.
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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
5 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
10 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
15 pervious zone 76 of the topsheet 32 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 pervious zone 76 tends to contain absorbed
fluids within
the absorbent core 34.
The compound sanitary napkin 20 may be extensible. The individual components
20 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
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21
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 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 SO 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 SO 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.
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22
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 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.
Now, referring to FIGS. 13 - 17, there is one of preferred, simplified process
flow
200 illustrating the assembly of the compound sanitary napkin 20 shown in FIG.
4. As
shown in FIG. 13, the process 200 for manufacturing the compound sanitary
napkin 20
may include several steps; a primary absorbent member making process (primary
absorbent member making section) 202, a secondary absorbent member making
process
(secondary absorbent making section) 204, a combining process of the primary
absorbent
member and the secondary absorbent member (combining section) 206, and a
cutting
process (cutting section) 208.
The primary absorbent member making process 202 further may include a
topsheet material feeding process (feeding section) 210, a primary absorbent
element
providing process (providing section) 212, a wrapping process (wrapping
section) 214
and a forwarding process (forwarding section) 216.
In the feeding section 210, a formed film web 220 and a nonwoven web 222 are
continuously fed from feed rolls 224 and 226 respectively toward a topsheet
joining unit
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228, such that the nonwoven web 222 superposes on the formed film web 220. The
continuous formed film web 220 and the continuous nonwoven web 222 are joined
by the
joining unit 228 to make the continuous topsheet web 230. As shown in FIG. 14,
the
joining unit 228 has a patterned roll 232 and an anvil roll 234. The patterned
roll 232 has
a series of patterned protrusions 236 on the surface of the patterned roll
232. One of or
both of the patterned roll 232 and/or the anvil roll 234 are biased toward
each other with a
predetermined pattern-element loading at the nip between the rolls 232 and
234. By
feeding the continuous formed film web 220 and the continuous nonwoven web 222
to
the nip of the joining unit 228 as shown in FIG. 14, the two webs are joined
at the discrete
dots 49 (refer to FIGS. 5 and 16) along the longitudinal sides 45 of the
continuous
topsheet web 230 by being applied pressure. A pattern of the discrete dots 49
corresponds to the pattern of the protrusions 236 of the roll 232. This joint
between the
continuous formed film web 220 and the continuous nonwoven web 222 allows
stable
transfer of the joined web. Alternatively, adhesive such as line adhesive,
spiral adhesive
or spot adhesive, ultrasonic bonding or heat bonding may be used to join the
formed film
web 220 and the nonwoven web 222. The continuous topsheet web 230 is then fed
toward a first adhesive applying section 238 where an intermittent spiral
adhesive 240 is
applied onto the absorbent core facing side of the continuous topsheet web
230, as shown
in FIG. 16, prior to provide the continuous topsheet web 230 with a discrete
absorbent
core 242. Alternatively, the adhesive applied to the continuous topsheet web
230 may be
substituted by spot adhesive, spray adhesive, line adhesive, or any known
method as long
as that can provide the preferred adhesive dimension in the adhesive width and
length
wise. Preferably, the adhesive width is preferred to keep the narrower
dimension
compared to the width of the absorbent core 242.
The continuous topsheet web 230 is fed to the primary absorbent element
providing section 212 by changing the direction upwardly. The providing
section 212
includes a cloud chamber 246 and a lay down drum 244 to make the discrete
absorbent
core 242 comprising hydrogel-forming polymers and fibers. The mixture of the
hydrogel-forming polymers and fibers transferred from the cloud chamber 246 to
the lay
down drum 244 forms a discrete shape of the absorbent core 242 by means of
vacuum
248 in the lay down drum 244 which has designed number of discrete pockets 250
on its
surface. As each discrete absorbent core 242 on the. lay down drum 244 reaches
to a
contact point with the continuous topsheet web 230, the discrete absorbent
core 242 is
transferred from the lay down drum 244 onto the surface of the continuous
topsheet web
230, as shown in FIGS. 13 and 16, where the intermittent spiral adhesive 240
is pre-
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applied. The discrete absorbent core 242 is transferred such that the body
facing side of
the discrete absorbent core 242 faces the continuous topsheet web 230 and such
that the
secondary absorbent member facing side 243 (refer to FIG. 16) of the discrete
absorbent
core 242 faces generally upwardly. This transfer is accomplished by means of
vacuum
252 in the transfer drum 254 and blow off air 256 in the lay down drum 248 as
the
continuous topsheet web 230 with the spiral adhesive 240 travels around the
surface of
the transfer drum 254. In addition, as the continuous topsheet web 230 travels
around the-
surface of the transfer drum 254, the continuous topsheet web 230 changes the
direction
generally horizontally so that the discrete absorbent core 242 easily keeps
staying on the
surface of the continuous topsheet web 230 by its weight. When the discrete
absorbent
core 24 transfers onto the continuous topsheet web 230, a first interval S is
provided
between the preceding discrete absorbent core 242 and the succeeding discrete
absorbent
core 242. The discrete absorbent core 242 secured to and carried by the
continuous
topsheet web 230 then goes through a calender rolls 260 that has a fixed
clearance. The
discrete absorbent core 242 is compressed by the calender rolls 260 to a
uniform caliper
prior to the wrapping process 214.
Alternatively, the continuous topsheet web 230 may be fed to the point between
the calender rolls 260 and the second adhesive applying section 262 after it
is applied
adhesive at the first adhesive applying section 238. In such a case, the
continuous
topsheet web 230 may not go through the primary absorbent element providing
section
212. The discrete absorbent core 242 may be forwarded toward the calender
rolls 260,
and then meet the continuous topsheet web 230 at the point after the calender
rolls 260 to
be transferred.
The cloud chamber 246 may feed only fibers onto the lay down drum 244 to make
the discrete absorbent core 242 including only fibers. Alternatively, if
necessary,
hydrogel-forming polymers may be added to the discrete absorbent core 242
including
only fibers after the primary absorbent element providing section 212.
Hydrogel-forming
polymers may be added before the wrapping process 214 (e.g., before the
folding section
264).
After the discrete absorbent core 242 is compressed, in the wrapping process
the
continuous topsheet web 230 with the discrete absorbent cord 24 is fed toward
a second
adhesive applying section 262. At the second adhesive applying section 262, a
continuous line adhesive 51 (refer to FIGS. 4, 5 and 16) is applied onto one
of the
longitudinal side 45 of the continuous topsheet web 230. The continuous
topsheet web
230 is then fed to a conventional folding section 264. In the folding section
264, and
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where the longitudinal sides 45 of the continuous topsheet web 230 is upwardly
folded
onto the base member facing side 243 of the discrete absorbent core 242 such
that each
longitudinal sides 45 overlaps to one another. Thereby the continuous topsheet
web 230
wraps the discrete absorbent core 242. At the exit of the folding section 264,
the
5 continuous line adhesive 51 allows the folded continuous topsheet web 230 to
create and
maintain the permanent attachment by attaching the both longitudinal sides 45
of the
continuous topsheet web 230 with having the discrete core 24 inside, and to
make a
continuous primary absorbent member web 266 as shown in FIG. 16. The permanent
attachment is preferable for this process to keep the stable dimension of the
continuous
10 primary absorbent member web 266 while it is being transferred to the
downstream.
Alternatively, any known attaching method such as spot adhesive, spray
adhesive, or
spiral adhesive may be used.
The continuous primary absorbent member web 266 is then transferred to the
downstream by means of horizontal drive conveyors 216 (i.e., forwarding
section). These
15 drive conveyors 216 can be substituted by the vacuum drive conveyors or
dead plate as
long as the tube web strain is maintained stable. If the distance between the
wrapping
section 214 and the combining section 206 is short, the forwarding section 216
may not
be necessary. In such a case, the wrapping section 214 may include a
forwarding section
to forward the continuous primary absorbent member web 266 to the combining
section
20 206.
The secondary absorbent member (base member) making process 204 further may
include a secondary absorbent member material feeding process (material
feeding
section) 270 and a joining process (joining section) 272.
In the material feeding section 270, a topsheet web 274, a secondary absorbent
25 element web 276, and a backsheet web 278 are continuously fed from feed
rolls 280, 282
and 284 respectively toward the joining section 272. The continuous backsheet
web 278
is fed toward a third adhesive applying section 286 where an intermittent line
adhesive is
applied onto the secondary absorbent element facing side of the continuous
backsheet
web 278 prior to provide the continuous backsheet web 278 with the secondary
absorbent
element 276. Alternatively, the adhesive applied to the continuous backsheet
web 278
may be substituted by spot adhesive, spray adhesive, spiral adhesive, or any
known
method. As explained hereinabove, in one of the preferred embodiment, the
secondary
absorbent element 276 may be a tissue layer. In the preferred embodiment in
FIG. 13, the
secondary absorbent element 276 may be prepared as a rolled continuous web.
Alternatively, the secondary absorbent element 276 may be fed as a discrete
absorbent
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element. As shown FIG. 13, the secondary absorbent element web 276 is fed to a
,conventional cut and space section 290. At the cut and space section, the
secondary
absorbent element web 276 is cut into the discrete secondary absorbent element
290 with
providing a second interval T (refer to FIG. 16) between the preceding
discrete secondary
absorbent element 290 and the succeeding discrete secondary absorbent element
288.
The discrete secondary absorbent element 288 is then put on the continuous
backsheet
web 278 and is secured to the continuous backsheet web 278 by the applied line
adhesive. -
The discrete secondary absorbent element 288 is then interposed between the
continuous
topsheet web 274 and the continuous backsheet web 278 to make a continuous
laminate
web 292 comprising the continuous topsheet web 274, the continuous backsheet
web 278
and the discrete secondary absorbent element 288. Preferably, the continuous
topsheet
web 274 may be applied adhesive such as line adhesive, spot adhesive, spray
adhesive, or
spiral adhesive before the discrete secondary absorbent element 288 is
interposed between
the continuous topsheet web 274 and the continuous backsheet web 278.
After making the continuous laminate web 292, it passes through the joining
section 272. The joining section 272 makes a permanent joint between the
continuous
topsheet web 274 and the continuous backsheet web 278 to make a continuous
secondary
absorbent member web 293. The joining process here may be used any known
method,
such as heat bonding 291, as shown in FIG. 16, by applying heat along the
periphery of
the secondary absorbent member 50. Alternatively, the method may include
applying
pressure, or heat and pressure. Further, adhesive may be applied to the
continuous
topsheet web 274 and/or the continuous backsheet web 278 as joining method.
The
continuous secondary absorbent member web 293 is then transferred to the
downstream
by means of, e.g., vacuum drive conveyors. As shown in FIG. 13, the continuous
secondary absorbent member web 293 is forwarded toward the continuous primary
absorbent member web 266 from the top with respect to the machine direction
conveying
the web 266 since the continuous primary absorbent member web 266 runs such
that the
secondary absorbent member facing side of the continuous primary absorbent
member
web 266 faces generally upward. Thereby, the continuous secondary absorbent
member
web 293 covers the attached longitudinal sides 45 of the continuous primary
absorbent
web 266.
After the joining section 272, the release liners 59 and 63 shown in FIG. 4
may be
applied onto the continuous backsheet web 278 of the secondary absorbent
member web
293. The release liners 59 and 63 may have adhesive such as line adhesive on
the surface
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facing the continuous backsheet web 278. The adhesive stays with the backsheet
when
the release liners 59 and 63 are removed for use.
The combining process 206 further may include an adhesive applying process
(adhesive applying section) 294 and a pressure applying process (pressure
applying
section) 296.
In the adhesive applying process 294, a continuous spiral adhesive 74 is
applied
by a fourth adhesive applying section 294 onto the continuous primary
absorbent member
web 266 while the continuous primary absorbent member web 266 is being
transferred by
a upwardly inclined drive vacuum conveyor 295. Alternatively, any known method
such
as line adhesive, spot adhesive, or spray adhesive, may be used. Preferably,
the spiral
adhesive 74 is applied such that the adhesive is sandwiched by the continuous
primary
absorbent member web 266 and the continuous secondary absorbent member web
293.
Preferably, the width of the spiral adhesive 74 does not extend beyond the
width PW of
the continuous primary absorbent member web 266. Alternatively, the adhesive
74 may
be applied underneath (i.e., the topsheet side) of the continuous secondary
absorbent
member web 293.
The continuous primary absorbent member web 266 and the continuous secondary
absorbent member web 293 are then forwarded toward nip rolls 298, where both
webs
266 and 293 are joined to one another by the spiral adhesive 74 to make a
continuous
compound sanitary napkin web 300. When the webs 266 and 293 meet each other at
the
nip rolls 298, it is arranged that at least a portion of the first interval S
between the
discrete primary absorbent core 242 and the second interval T of the discrete
secondary
absorbent element 288 overlaps to each other as shown in FIG. 16. Arranging
the
overlapped portion X allows the continuous compound sanitary napkin web 300 to
have a
region where no absorbent element exists to give the compound sanitary napkin
20 the
transverse ends 18.
The continuous compound sanitary napkin web 300 is then fed toward a pressure
applying section 296 as shown in FIG. 13. The pressure applying section 296
applies
pressure at the discrete dots 72 to the overlapped portion X along a
transverse direction
such that the continuous primary absorbent member web 266 and the continuous
secondary absorbent member web 293 are combined. As shown in FIG. 15, the
pressure
applying section 296 has a patterned roll 302 and an anvil roll 304. The
patterned roll
302 has a series of patterned protrusions 306 on the surface of the patterned
roll 302. One
of or both of the patterned roll 302 andlor the anvil roll 304 are biased
toward each other
with a predetermined pattern-element loading at the nip between the rolls 302
and 304.
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By feeding the continuous compound sanitary napkin web 300 to the nip of the
pressure
applying section 296, the two webs 266 and 296 are combined at the discrete
dots 72 by
being applied pressure. A pattern of the discrete dots 72 corresponds to the
pattern of the
protrusions 306 of the roll 302. This combine at the transverse ends 18 (i.e.,
the
overlapped portion X) preferably has sufficient peel strength (e.g., the
nonwoven 222 to
nonwoven 222 surface). Preferably such peel strength may be more than 100
grams per
inch. This can be achieved by an operation of ( 1 ) at least 60,000 psi per
nip area pressure, -
2) surface temperature of the rolls of 70°C - 90°C, and 3)
interference of the two rolls of
O.OSmm - 0.08m. It is also preferred that the velocity of the continuous
compound
sanitary napkin web 300 is controlled at 110m/min - 155m/min or more.
Optionally, the
roil surface velocity of the patterned roll 302 and the anvil roll 304 may be
different from
each other. Further, the roll surface velocity of the patterned roll 302 and
the anvil roll
304 may be a little faster (e.g., 0 % - 3 %) than the velocity of the
continuous compound
sanitary napkin web 300. Optionally, adhesive 241 may be applied at the first
interval S
in order to enhance the peel strength between the nonwoven 222 to nonwoven 222
surface
as shown in FIG. 16. This adhesive may be applied at the same point as the
second
adhesive applying section 262 before the continuous topsheet web 230 is
folded. Because
both the continuous primary absorbent member web 266 and the continuous
secondary
absorbent member web 293 are arranged to have the same strain by being
forwarded
continuously before combining, the compound sanitary napkin does not get
curved even
after being cut into a discrete sanitary napkin. Alternatively, if desired, it
may get curved
by the webs 266 and 293 having different strain from each other.
The cutting process 208 may includes a cutter 302. The continuous compound
sanitary napkin web 300 is forwarded to the cutter 302 and is cut into a
discrete segment
having a final shape (i.e., discrete compound sanitary napkin 20). The cutter
302 may be
a conventional cutter having a die cutter. Alternatively, any other known
method to cut
may be used.
Many alternative methods for the above described process may be used. The
joining process 272 may be done after the combining process 206 and before
cutting
process 208. In such a case, the topsheet web 274, the secondary absorbent
element 288
and the backsheet web 278 may be joined temporarily by any suitable means,
such as
adhesive before the combining process 206. The discrete secondary absorbent
member
288 may be provided onto the topsheet web 274, instead of being provided onto
the
backsheet web 278.
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Referring to FIGS. 18 - 20, there is another preferred, simplified process
flow 400
illustrating the assembly of the compound sanitary napkin 20. As shown in FIG.
18, the
process 400 for manufacturing the compound sanitary napkin 20 may include
several
steps; a primary absorbent member making process (primary absorbent member
making
section) 202, a secondary absorbent member material feeding process (secondary
absorbent feeding section) 402, a combining process (combining section) 404,
and a
cutting process (cutting section) 208. The primary absorbent member making
process-
202 may include the generally same process as described in FIG. 13, such as
the topsheet
material feeding process (feeding section) 210, a primary absorbent element
providing
process (providing section) 212, a wrapping process (wrapping section) 214 and
a
forwarding process (forwarding section) 216. Because the function of these
process may
be the same as the above described corresponding process, a detailed
description may be
referred to the above description. The combining section 404 may include the
adhesive
applying process (adhesive applying section) 294 and a pressure applying
process
(pressure applying section) 406.
In the secondary absorbent feeding process 402, the continuous backsheet web
278 is fed from the feed roll 284 and then applied the intermittent line
adhesive at the
third adhesive applying section 286. The continuous secondary absorbent
element web
276 is fed from the feed roll 282 and then cut into the discrete secondary
absorbent
element 288 by the cut and space section 290. The discrete secondary absorbent
element
288 is provided onto the continuous backsheet web 278 with the second interval
T and
secured thereon by the line adhesive. The continuous topsheet web 274 is fed
from the
feed roll 280. The continuous topsheet web 274 and the continuous backsheet
web 278
with the discrete secondary absorbent element 288 are then separately
forwarded to the
combining section 404 as shown in FIG. 18. On the other hand, the primary
absorbent
member web 266, after being applied the spiral adhesive 74 by the fourth
adhesive
applying section 294, is also forwarded toward the combining section 404. The
continuous topsheet web 274, the continuous backsheet web 278 with the
discrete
secondary absorbent element 288 and the continuous primary absorbent member
web 266
meet at the pressure applying section 406. It is arranged that at least a
portion of the first
interval S and the second interval T overlaps to each other at the pressure
applying
section 406 as shown in FIG. 19.
All the continuous webs 274, 278 and 266 may be combined by applying pressure
at the discrete dots 72 in the overlapped portion X along the transverse
direction. In
addition, the continuos topsheet web 274 and the continuous backsheet web 278
may be
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joined at the pressure applying section 406 to make the continuous compound
sanitary
napkin web 300. In such a case, the pressure applying section 406 may include
applying
heat along the periphery of the secondary absorbent member 50 to make heat
bonding
291. Alternatively, the periphery of the secondary absorbent member 50 may be
joined
5 by applying only pressure by the pressure applying section 406. The
continuous
compound sanitary napkin web 300 may be then forwarded to the cutting process
208 and
cut into the discrete segment having a final shape (i.e., discrete compound
sanitary napkin-
20).
Referring to FIGS. 21 - 23, there is another preferred, simplified process
flow 500
10 illustrating the assembly of the compound sanitary napkin 20. As shown in
FIG. 21, the
process 500 for manufacturing the compound sanitary napkin 20 may include
several
steps; a primary absorbent member making process (primary absorbent member
making
section) 202, a first base member feeding process (first base member feeding
section)
502, a combining process (combining section) 504, a second base member feeding
15 process (second base member feeding section) 506, a joining process
(joining section)
508 and a cutting process (cutting section) 208. The primary absorbent member
making
process 202 may include the generally same process as described in FIGS. 13
and 18,
such as the topsheet material feeding process (feeding section) 210, a primary
absorbent
element providing process (providing section) 212, a wrapping process
(wrapping
20 section) 214 and a forwarding process (forwarding section) 216. Because the
function of
these process may be the same as the above described corresponding process, a
detailed
description may be referred to the above description. The combining section
504 may
include the adhesive applying process (adhesive applying section) 294 and a
pressure
applying process (pressure applying section) 506.
25 In the first base member feeding process 502, the continuous topsheet web
274 as
a base member is fed from the feed roll 280 and then applied the intermittent
line
adhesive at the fifth adhesive applying section S 10. The continuous secondary
absorbent
element web 276 is fed from the feed roll 282 and then cut into the discrete
secondary
absorbent element 288 by a cut and space section S I2 which can use the same
equipment
30 used for the cut and space section 290 in FIGS 13 and 18. The discrete
secondary
absorbent element 288 is provided onto the continuous topsheet web 274 with
the second
interval T and secured thereon by the line adhesive. The continuous topsheet
web 274
with the discrete secondary absorbent element 288 are then forwarded to the
pressure
applying section 506 as shown in FIG. 21. On the other hand, the primary
absorbent
member web 266, after being applied the spiral adhesive 74 by the fourth
adhesive
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applying section 294, is also forwarded toward the pressure applying section
506. The
continuous topsheet web 274 with the discrete secondary absorbent element 288
and the
continuous primary absorbent member web 266 meet at the combining section 506.
It is
arranged that at least a portion of the first interval S and the second
interval T overlaps to
each other at the pressure applying section 506 as shown in FIG. 22. The
continuous
webs 274 and 266 may be combined by applying pressure at the discrete dots 72
in the
overlapped portion X along the transverse direction to make a continuous
composite web
510. Then the composite web 510 is forwarded to the joining section 508. The
continuous backsheet web 278 is fed from the feed roll 284 and then fed to the
joining
section 508.
After the pressure applying section 506, the continuous topsheet web 274 of
the
continuous composite web 510 and the continuous backsheet web 278 may be
joined to
make the continuous compound sanitary napkin web 512 at the joining section
508. The
joining section 508 may include applying heat along the periphery of the
secondary
absorbent member 50 to make heat bonding 291. Alternatively, the periphery of
the
secondary absorbent member 50 may be joined by applying only pressure, or
pressure and
heat by the joining section 508. The continuous compound sanitary napkin web
512 may
be then forwarded to the cutting process 208 and cut into the discrete segment
having a
final shape (i.e., discrete compound sanitary napkin 20).
While continuous webs 220, 222, 274, 276 and 278 are fed from each feed roll,
a
discrete material may be alternatively fed. In FIG. 13, a discrete formed film
and a
discrete nonwoven may be fed toward the joining unit 228 to make a discrete
topsheet. In
such a case, a discrete absorbent core may be provided onto the discrete
topsheet. The
discrete topsheet may be folded to wrap the discrete absorbent core to make a
discrete
primary absorbent member. The discrete primary absorbent member may be
forwarded
toward the combining section 206. A discrete topsheet, a discrete backsheet
and a
discrete secondary absorbent may be fed toward the joining section 272 to make
a
discrete secondary absorbent member. The discrete secondary absorbent member
may be
forwarded toward the combining section 206, Then, the discrete primary
absorbent
member and the discrete secondary absorbent member may be combined. In this
alternative method, the cutting section 208 may be unnecessary.
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.
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It is therefore intended to cover the appended claims all such changes and
modifications
that are within the scope of this invention.
