Panties abstract
The present invention relates to absorbent articles such as sanitary
napkins, panty liners, and incontinence pads. More particularly,
the present invention relates to absorbent articles, such as sanitary
napkins, that have longitudinal side edge components that naturally
wrap the sides of a wearer's panties which provide an alternative
to conventional side flaps.
Panties claims
What is claimed is:
1. An absorbent article for wearing in a crotch region of an undergarment,
said absorbent article having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, a longitudinal centerline, and a transverse
centerline, said absorbent article comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
an undergarment covering component, said undergarment covering
component being joined to the garment-facing side of said main body
portion inboard of the longitudinal side edges of said main body
portion at affixation points and being otherwise unattached to said
main body portion laterally outboard of at least some of said affixation
points, said undergarment covering component comprising a pair of
side wrapping elements for folding around a side of a crotch region
of an undergarment, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion
a distance of less than one-half the width of said main body portion
to distal edges, wherein at least a portion of said undergarment
covering component is extensible generally in the longitudinal direction
between said affixation points and said distal edges of said side
wrapping elements when said side wrapping elements are folded around
a side of a crotch portion of an undergarment, and said extensible
portion of said undergarment covering component has a return force
of less than or equal to about 100 grams.
2. The absorbent article of claim 1 wherein said return force is
less than or equal to about 50 grams.
3. The absorbent article of claim 2 wherein said return force is
less than or equal to about 25 grams.
4. An absorbent article for wearing in a crotch region of an undergarment,
said absorbent article having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, a longitudinal centerline, and a transverse
centerline, said absorbent article comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
undergarment covering component, said undergarment covering component
being joined to the garment-facing side of said main body portion
inboard of the longitudinal side edges of said main body portion
at affixation points and being otherwise unattached to said main
body portion laterally outboard of at least some of said affixation
points, said undergarment covering component comprising a pair of
side wrapping elements for folding around a side of a crotch region
of an undergarment, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion
a distance of less than one-half the width of said main body portion
to distal edges, wherein at least a portion of said undergarment
covering component is extensible generally in the longitudinal direction
between said affixation points and said distal edges of said side
wrapping elements when said side wrapping elements are folded around
a side of a crotch portion of an undergarment, wherein said extensible
portions have a set of greater than or equal to about 10%.
5. The absorbent article of claim 4 wherein said extensible portions
have a set of greater than or equal to about 20% .
6. An absorbent article for wearing in a crotch region of an undergarment,
said absorbent article having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, a longitudinal centerline, and a transverse
centerline, said absorbent article comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
undergarment covering component, said undergarment covering component
being joined to the garment-facing side of said main body portion
inboard of the longitudinal side edges of said main body portion
at affixation points and being otherwise unattached to said main
body portion laterally outboard of at least some of said affixation
points, said undergarment covering component comprising a pair of
side wrapping elements for folding around a side of a crotch region
of an undergarment, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion
a distance of less than one-half the width of said main body portion
to distal edges, wherein at least a portion of said undergarment
covering component is extensible generally in the longitudinal direction
between said affixation points and said distal edges of said side
wrapping elements when said side wrapping elements are folded around
a side of a crotch portion of an undergarment, wherein said side
wrapping elements each have a resistance to edge compression of
greater than or equal to about 5 grams force.
7. An absorbent article for wearing in a crotch region of an undergarment,
said absorbent article having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, a longitudinal centerline, and a transverse
centerline, said absorbent article comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
undergarment covering component, said undergarment covering component
being joined to the garment-facing side of said main body portion
inboard of the longitudinal side edges of said main body portion
at affixation points and being otherwise unattached to said main
body portion laterally outboard of at least some of said affixation
points, said undergarment covering component comprising a pair of
side wrapping elements for folding around a side of a crotch region
of an undergarment, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion
a distance of less than one-half the width of said main body portion
to distal edges, wherein at least a portion of said undergarment
covering component is extensible generally in the longitudinal direction
between said affixation points and said distal edges of said side
wrapping elements when said side wrapping elements are folded around
a side of a crotch portion of an undergarment, wherein said side
wrapping elements each have a resistance to edge compression of
greater than or equal to about 10 grams force.
8. An absorbent article for wearing in a crotch region of an undergarment,
said absorbent article having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, a longitudinal centerline, and a transverse
centerline, said absorbent article comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of an undergarment, said side wrapping
elements being joined to the garment-facing side of said main body
portion inboard of the longitudinal side edges of said main body
portion at affixation points and being otherwise unattached to said
main body portion laterally outboard of at least some of said affixation
points, said side wrapping elements extending laterally outward
beyond the longitudinal side edges of said main body portion, wherein
at least a portion of said side wrapping elements is extensible
between said affixation points and said distal edges of said side
wrapping elements when said side wrapping elements are folded around
a side of a crotch portion of an undergarment, and said extensible
portion of said side wrapping elements has a return force of less
than or equal to about 100 grams.
9. A sanitary napkin for wearing in a crotch region of a pair of
panties, said sanitary napkin having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, said sanitary napkin comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of an undergarment, said side wrapping
elements being joined to the garment-facing side of said main body
portion at affixation points that are inboard of the longitudinal
side edges of said main body portion and being otherwise unattached
to said main body portion laterally outboard of at least some of
said affixation points, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion,
wherein at least a portion of said side wrapping elements is extensible
when said side wrapping elements are folded at least partially around
a side of a crotch portion of a pair of panties, and said extensible
portions of said side wrapping elements have a return force of less
than or equal to about 100 grams.
10. A sanitary napkin for wearing in a crotch region of a pair
of panties, said sanitary napkin having a longitudinal dimension
extending in a longitudinal direction and a transverse dimension
extending in a transverse direction, said sanitary napkin comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of a pair of panties, said side
wrapping elements being joined to the garment-facing side of said
main body portion inboard of the longitudinal side edges of said
main body portion at affixation points and being otherwise unattached
to said main body portion laterally outboard of at least some of
said affixation points, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion
a distance of less than one-half the width of said main body portion
to distal edges, wherein at least a portion of each of said side
wrapping elements is extensible generally in the longitudinal direction
in an amount between about 10% and about 40% under any force within
the range of between about 50 grams and about 1,500 grams between
said affixation points and said distal edges of said side wrapping
elements when said side wrapping are folded when said side wrapping
elements are folded at least partially around a side of a crotch
portion of a pair of panties and said extensible portions of said
side wrapping elements have a return force of less than or equal
to about 100 grams.
11. An absorbent article for wearing in a crotch region of an undergarment,
said absorbent article having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, a longitudinal centerline, and a transverse
centerline, said absorbent article comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of an undergarment, said side wrapping
elements being joined to the garment-facing side of said main body
portion inboard of the longitudinal side edges of said main body
portion at affixation points and being otherwise unattached to said
main body portion laterally outboard of at least some of said affixation
points, said side wrapping elements extending laterally outward
beyond the longitudinal side edges of said main body portion, wherein
at least a portion of said side wrapping elements is extensible
generally in the longitudinal direction between said affixation
points and said distal edges of said longitudinal side portions
when said side wrapping elements are folded at least partially around
a side of a crotch portion of an undergarment, and said extensible
portion of said side wrapping elements has a set of greater than
or equal to about 10%.
12. A sanitary napkin for wearing in a crotch region of a pair
of panties, said sanitary napkin having a longitudinal dimension
extending in a longitudinal direction and a transverse dimension
extending in a transverse direction, said sanitary napkin comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of a pair of panties, said side
wrapping elements being joined to the garment-facing side of said
main body portion inboard of the longitudinal side edges of said
main body portion at affixation points and being otherwise unattached
to said main body portion laterally outboard of at least some of
said affixation points, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion
a distance of less than one-half the width of said main body portion
to distal edges, wherein at least a portion of each of said side
wrapping elements is extensible generally in the longitudinal direction
in an amount between about 10% and about 40% under any force within
the range of between about 50 grams and about 1,500 grams between
said affixation points and said distal edges of said side wrapping
elements when said side wrapping elements are folded at least partially
around a side of a crotch portion of a pair of panties and said
extensible portions of said side wrapping elements have a set of
greater than or equal to about 10%.
13. An absorbent article for wearing in a crotch region of an undergarment,
said absorbent article having a longitudinal dimension extending
in a longitudinal direction and a transverse dimension extending
in a transverse direction, a longitudinal centerline, and a transverse
centerline, said absorbent article comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of an undergarment, said side wrapping
elements being joined to the garment-facing side of said main body
portion inboard of the longitudinal side edges of said main body
portion at affixation points and being otherwise unnattached to
said main body portion laterally outboard of at least some of said
affixation points and extending laterally outward beyond the longitudinal
side edges of said main body portion to a distal edge, wherein at
least a portion of said side wrapping elements is extensible when
said side wrapping elements are folded at least partially around
a side of a crotch portion of an undergarment and said side wrapping
elements have a resistance to edge compression of greater than or
equal to about 5 grams force.
14. A sanitary napkin for wearing in a crotch region of a pair
of panties, said sanitary napkin having a longitudinal dimension
extending in a longitudinal direction and a transverse dimension
extending in a transverse direction, said sanitary napkin comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of an undergarment, said side wrapping
elements being joined to the garment-facing side of said main body
portion at affixation points that are inboard of the longitudinal
side edges of said main body portion and being otherwise unattached
to said main body portion laterally outboard of at least some of
said affixation points, said side wrapping elements extending laterally
outward beyond the longitudinal side edges of said main body portion,
wherein at least a portion of said side wrapping elements is extensible
when said side wrapping elements are folded at least partially around
a side of a crotch portion of a pair of panties, and said extensible
portions of said side wrapping elements have a resistance to edge
compression of greater than or equal to about 5 grams force.
15. A sanitary napkin for wearing in a crotch region of a pair
of panties, said sanitary napkin having a longitudinal dimension
extending in a longitudinal direction and a transverse dimension
extending in a transverse direction, a longitudinal centerline,
and a transverse centerline, said sanitary napkin comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of a pair of panties, said side
wrapping elements being joined to said main body portion inboard
of the longitudinal side edges of said main body portion at affixation
points and being otherwise unnattached to said main body portion
laterally outboard of at least some of said affixation points and
extending laterally outward beyond the longitudinal side edges of
said main body portion a distance of less than about one-half the
width of said main body portion to a distal edge, wherein at least
a portion of said side wrapping elements is extensible when said
side wrapping elements are folded at least partially around a side
of a crotch portion of an undergarment and said side wrapping elements
have a resistance to edge compression of greater than or equal to
about 5 grams force.
16. A sanitary napkin for wearing in a crotch region of a pair
of panties, said sanitary napkin having a longitudinal dimension
extending in a longitudinal direction and a transverse dimension
extending in a transverse direction, a longitudinal centerline,
and a transverse centerline, said sanitary napkin comprising:
a main body portion comprising an absorbent core, said main body
portion having a body-facing side, a garment-facing side, and a
pair of longitudinal side edges; and
a pair of side wrapping elements for folding at least partially
around a side of a crotch region of a pair of panties, said side
wrapping elements being joined to said main body portion inboard
of the longitudinal side edges of said main body portion at affixation
points and being otherwise unnattached to said main body portion
laterally outboard of at least some of said affixation points and
extending laterally outward beyond the longitudinal side edges of
said main body portion a distance of less than about one-half the
width of said main body portion to a distal edge, wherein at least
a portion of said side wrapping elements is extensible between about
10% and about 40% in the longitudinal direction under any force
within the range of between about 50 grams and about 1,500 grams
when said side wrapping elements are folded at least partially around
a side of a crotch portion of a pair of panties, and said extensible
portion has a return force of less than or equal to about 100 grams
and a set of greater than or equal to about 10%, and said side wrapping
elements have a resistance to edge compression of greater than or
equal to about 5 grams force.
Panties description
FIELD OF THE INVENTION
The present invention relates to absorbent articles such as sanitary
napkins, panty liners, and incontinence pads. More particularly,
the present invention relates to sanitary napkins that have longitudinal
side edge components that naturally wrap the sides of a wearer's
panties which provide an alternative to conventional side flaps.
BACKGROUND OF THE INVENTION
Absorbent articles such as sanitary napkins, pantiliners, and incontinence
pads are devices that are typically worn in the crotch region of
an undergarment. These devices are designed to absorb and retain
liquid and other discharges from the human body and to prevent body
and clothing soiling. Sanitary napkins are a type of absorbent article
worn by women in a pair of panties that are normally positioned
between the wearer's legs, adjacent to the perineal area of the
body. Sanitary napkins both with and without side flaps (or wings)
are disclosed in the literature and are available in the marketplace.
Some particularly preferred sanitary napkins that do not require
flaps are described in U.S. Pat. No. 4,950,264 and 5,009,653 issued
to Osborn on Aug. 21, 1990 and Apr. 23, 1991, respectively.
Generally when sanitary napkins are provided with flaps, the flaps
extend laterally from a central absorbent means and are intended
to be folded around the edges of the wearer's panties in the crotch
region. Thus, the flaps are disposed between the edges of the wearer's
panties in the crotch region and the wearer's thighs. Commonly,
the flaps are provided with an attachment means for either affixing
the flaps to the underside of the wearer's panties or to the opposing
flap. The flaps are particularly effective for preventing exudates
from soiling the edges of the wearer's panties.
Sanitary napkins having flaps of various types are disclosed in
U.S. Pat. No. 4,687,478, entitled "Shaped Sanitary Napkin With
Flaps", which issued to Van Tilburg on Aug. 18, 1987; U.S.
Pat. No. 4,608,047, entitled "Sanitary Napkin Attachment Means",
which issued to Mattingly on Aug. 26, 1986; U.S. Pat. No. 4,589,876,
entitled "Sanitary Napkin", which issued to Van Tilburg
on May 20, 1986 and its Reexamination Pat. No. B14,589,876, Certificate
of Reexamination issued Apr. 27, 1993; U.S. Pat. No. 4,285,343,
entitled "Sanitary Napkin", which issued to McNair on
Aug. 25, 1981; U.S. Pat. No. 3,397,697, entitled "Disposable
Sanitary Shield For Undergarments", which issued to Rickard
on Aug. 20, 1968; and, U.S. Pat. No. 2,787,271, entitled "Sanitary
Napkin", which issued to Clark on Apr. 2, 1957.
While sanitary napkins having flaps are commonly viewed as providing
better protection against soiling as compared to sanitary napkins
without flaps, some women find applying sanitary napkins having
flaps to be inconvenient for various reasons. For instance, some
women find it to be difficult to attach the flaps to the underside
of the crotch of their panties. This can be due to factors such
as the tendency for the adhesive fasteners on the flaps to stick
to themselves or to other parts of the sanitary napkin. As a result,
some women still prefer a sanitary napkin without flaps, and some
women who generally prefer a sanitary napkin with flaps, occasionally
(such as during periods of light flow) prefer a sanitary napkin
without flaps. Therefore, there is a need for a sanitary napkin
which provides an alternative to sanitary napkins having conventional
side flaps while still providing the protection of side flaps.
In addition, both sanitary napkins with and without flaps are subject
to the problem that the wearer's undergarments move with the wearer's
movements during wear. These stresses may cause the sanitary napkin
to shift from its desired position in the wearer's undergarment.
Most sanitary napkins, however, provide no mechanism for adjusting
to these movements. This puts stresses on the sanitary napkin and
the flaps. The failure to provide the sanitary napkin with a mechanism
to adjust to the difference between the movement of the wearer's
undergarments and the wearer's body may also cause the sanitary
napkin to be not as comfortable as it could be than if it stretched
and conformed with the wearer's movements and to the wearer's undergarments.
Several variations of sanitary napkins having conventional flaps
that attempt to solve some, but not all of these problems are disclosed
in the patent literature. For example, U.S. Pat. No. 4,911,701 issued
to Mavinkurve discloses a sanitary napkin having elastic strands
for providing a greater convex shape to the body-facing portion
of the central absorbent and for enabling adhesive-free placement
of the flaps of a winged napkin embodiment into a pair of panties.
The sanitary napkin described in this patent, however, still appears
to require the user to manipulate the flaps (by first flipping the
flaps upward and then placing the flaps in her panties and flipping
the flaps back down) since the flaps appear to be pre-disposed to
be in a downward folded condition. The Mavinkurve patent also requires
that individual elastic strands be attached in a contracted condition
to the central absorbent portion of the napkin and/or to its wings
or flaps. The napkins described in the Mavinkurve patent can, therefore,
be difficult and expensive to manufacture. The Mavinkurve patent
also does not disclose any mechanism to account for differences
in movement and extensibility of the central absorbent of the napkin
and the wearer's panties.
U.S. Pat. No. 4,940,462 issued to Salerno discloses a sanitary
napkin with longitudinally expandable flaps. The flaps are designed
to fold over the exterior of the wearer's panty and then to expand
to conform with the contour of the panties. The Salerno patent,
however (in Column 5), appears to require conventional adhesive
fasteners to retain the flaps in place on the underside of the wearer's
panties. Further, the sanitary napkin shown in the Salerno patent
suffers from several drawbacks due to the fact that the longitudinally
expandable flaps extend directly outward from the longitudinal sides
of the absorbent element. The expandable flaps in Salerno are attached
directly to an inextensible body. This limits the extensibility
of the portions of the Salerno flaps that are located adjacent to
the absorbent element. In order for the Salerno flaps to extend
an amount sufficient to wrap around the panty elastics, the flaps
have to have a relatively wide transverse dimension. This is shown
in FIGS. 3 and 4 of the Salerno reference. The extra flap material
can extend too far outward beyond the panty elastics to create a
sloppy border that hangs out of the wearer's panties.
Another drawback to the flap construction shown in both the Mavinkurve
and Salerno references is that the attachment of the expandable
flaps directly to the longitudinal sides of the absorbent element
leads to the problem that any compression of the absorbent element
will cause the flaps to retract transversely inward. Any bunching
of the absorbent element in the sanitary napkins shown in these
references, such as that caused by compression by the wearer's legs,
causes the flaps to lose their ability to cover a given area of
the wearer's panties. The Salerno patent, like the Mavinkurve patent,
also does not disclose any mechanism to account for differences
in movement and extensibility of the central portion of the napkin
and the wearer's panties.
Thus, a need exists for an absorbent article, such as a sanitary
napkin, that is provided with an alternative to conventional flaps.
In particular, a need exists for a sanitary napkin having an alternative
to conventional flaps which provides the protection from soiling
of conventional flaps and which can conveniently and efficiently
solve the problems caused when attempting to attach conventional
flaps to the underside of the wearer's panties and of the failure
of the sanitary napkins having conventional flaps to stretch to
conform to the wearer's body and the wearer's panties. A need also
exists for a sanitary napkin that has a mechanism to adjust to the
difference between the movement of the wearer's panties and the
wearer's body.
It is, therefore, an object of the present invention to provide
an absorbent article, such as a sanitary napkin, that is able to
provide coverage to the wearer's panties to reduce side soiling
(i.e., staining of the edges of the panty crotch) without the use
of conventional flaps.
It is another object of the present invention to provide an absorbent
article, such as a sanitary napkin that automatically wraps around
the sides of the wearer's panties by the simple action of the wearer
pulling up her panties.
It is still another object of the present invention to provide
an absorbent article, such as a sanitary napkin, that is able to
wrap around the sides of the wearer's panties and stay without providing
flaps having panty fasteners thereon, and without attaching separate
elastic strands to the sanitary napkin.
It is another object of the present invention to provide an absorbent
article, such as a sanitary napkin that has a mechanism for attachment
of the sanitary napkin to the wearer's panties that stretches to
conform to the wearer's body and the wearer's panties, and responds
to the wearer's movements to allow better conformation between the
sanitary napkin and the wearer's body and between the sanitary napkin
and the wearer's panties.
It is yet another object of this invention to provide an absorbent
article, particularly a relatively thin absorbent article, such
as a sanitary napkin, that is capable of extending, or more preferably,
stretching when the article is worn for improved comfort and fit.
These and other objects of the present invention will be more readily
apparent when considered in reference to the following description
and when taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention provides an absorbent article, such as a
sanitary napkin. The sanitary napkin of the present invention has
an undergarment covering component (or "panty covering component")
that provides coverage to the wearer's panties to reduce side soiling
(i.e., staining of the edges of the panty crotch) without the use
of conventional flaps.
The sanitary napkin comprises a main body portion comprising a
liquid pervious topsheet; a liquid impervious backsheet joined to
the topsheet; and an absorbent core positioned between the topsheet
and the backsheet. The undergarment covering component (or panty
covering component) is joined to the main body portion. The undergarment
covering component is wider than the crotch region of the undergarment.
The undergarment covering component has a pair of short, flexible
(and in some embodiments, drapable) longitudinal side portions (or
"side wrapping elements") that extend beyond the crotch
edge portions of the wearer's undergarment. The side wrapping elements
have a high fold retention. The undergarment covering component
comprises at least some extensible portions that are provided with
a low return force or no return force (force that tends to cause
the extensible portions to retract after they have been extended).
Preferably, the extensible portions comprise at least a portion
of the undergarment covering component which is located between
the affixation points where the undergarment covering component
is joined to the main body portion and the distal edges of the side
wrapping elements. The fact that the extensible portions are provided
with a low return force and the side wrapping elements have a high
fold retention allows the side wrapping elements of the undergarment
covering component to automatically fold around the crotch edge
portions of the wearer's undergarment toward the underside of the
undergarment and to remain so folded when the absorbent article
is placed in an undergarment and the undergarment is pulled up adjacent
the wearer's body.
The extensible portions of the undergarment covering component
may comprise any type of extensible structure, including materials
that have an inherent extensibility and materials that are gathered,
pleated, or otherwise formed into extensible structures. These portions
can be extensible in the longitudinal direction, the transverse
direction, or both. The undergarment covering component can comprise
a laminate of one or more nonwoven materials and an elastomeric
film. In one alternative version of this laminate embodiment, the
elastomeric film can be present in all but the four regions of the
laminate where the periphery of the undergarment covering element
intersects with the edges of the wearer's panty crotch. In other
embodiments, the undergarment covering component can be extensible
only in these four regions and inextensible everywhere else.
A non-limiting number of additional variations of the undergarment
covering component are described herein. For instance, the undergarment
covering component can comprise the backsheet of the sanitary napkin.
In still other embodiments, the sanitary napkin can comprise an
undergarment covering component which is a separate element that
is attached to the main body portion of the sanitary napkin at spaced
apart attachment zones. The undergarment covering component is unattached
to the main body portion between the attachment zones to provide
unattached portions of the undergarment covering component in the
central region of the main body portion. The unattached portions
of the undergarment covering component are capable of separating
from the main body portion so that the main body portion of the
sanitary napkin can stay in contact with the wearer's body and the
undergarment covering component can stay attached to the wearer's
panties even when the panties pull away from the wearer's body during
wear.
In variations of this latter embodiment, the undergarment covering
component can be joined to the main body portion of the sanitary
napkin by material that has slack built into it by providing flaccid
material, pleated material, extensible material, or the like between
the main body portion and the undergarment covering component. Numerous
other variations are possible. For example, the sanitary napkin
of the present invention may comprise a main body portion that has
its longitudinal side margins folded inward underneath the main
body portion of the sanitary napkin and the longitudinal side margins
attached to an extensible panty covering component that extends
outward beyond the longitudinal side margins of the main body portion.
In still another embodiment, the sanitary napkin comprises an extensible
main body portion (including an extensible topsheet that is attached
to an extensible backsheet which extends beyond the longitudinal
edges of the absorbent core).
The sanitary napkin of the present invention provides an alternative
to sanitary napkins having conventional side flaps for several reasons.
The undergarment covering component does not extend far enough outward
beyond the side edges of the wearer's panties to cause any inconvenience
to the wearer. The undergarment covering component requires no action
on the part of the wearer to fold the side wrapping elements under
her panties or to attach the same to her panties. The undergarment
covering component stays in place well enough to cover the sides
edges of the wearer's panties without affixing it to the outside
surface of the panties.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing
out and distinctly claiming the subject matter which is regarded
as forming the present invention, it is believed that the invention
will be better understood from the following description which is
taken in conjunction with the accompanying drawings in which:
FIG. 1 is a top plan view of a preferred embodiment of the sanitary
napkin of the present invention.
FIG. 2 is a schematic sectional view taken along line 2--2 of the
sanitary napkin shown in FIG. 1.
FIG. 3 is a side view of the sanitary napkin shown in FIG. 1 shown
before use.
FIG. 4 is a side view of the sanitary napkin shown in FIG. 1 (taken
from an angle similar to that of FIG. 3) in an in-use configuration.
FIG. 5 is an end view of the sanitary napkin shown in FIG. 1 in
an in-use configuration.
FIG. 6 is a top plan view showing the extensibility of the main
body portion of the sanitary napkin shown in FIG. 1.
FIG. 7 is a table which shows preferred relationships between the
magnitude of stretching forces applied to the sanitary napkin and
the amount the sanitary napkin stretches in response to such forces.
FIG. 8 is a plan view of an absorbent core that is provided with
slits in the central region of the same.
FIG. 9 is a simplified end view of a known sanitary napkin having
longitudinally extensible flaps which, for simplicity, is shown
with the flaps extended instead of being folded around the edges
of a crotch of an undergarment as they normally would be during
use.
FIG. 9A is a simplified end view of the sanitary napkin shown in
FIG. 9 after the absorbent element has been compressed.
FIG. 10 is a simplified end view of an extensible sanitary napkin
having extensible side wrapping elements.
FIG. 11 is a simplified end view (similar to that of FIG. 9) showing
a sanitary napkin having a panty covering component that is joined
underneath the main body portion of the sanitary napkin at points
of attachment that are inboard of the longitudinal edges of the
main body portion.
FIG. 11A is a simplified end view of the sanitary napkin shown
in FIG. 11 after the absorbent element has been compressed.
FIG. 12 is a simplified end view of a sanitary napkin similar to
that of FIG. 11, only with the points of attachment being in the
region of the longitudinal centerline of the sanitary napkin.
FIG. 12A is a simplified end view of the sanitary napkin shown
in FIG. 12 after the absorbent element has been compressed.
FIG. 13 is a simplified end view (similar to that of FIG. 11) showing
of a sanitary napkin having a first type of structure which allows
a portion of the main body portion of the sanitary napkin to decouple
(or move apart) from the panty covering component.
FIG. 13A is a simplified end view of the sanitary napkin shown
in FIG. 13 after the absorbent element has been compressed.
FIG. 14 is a simplified end view (similar to that of FIG. 11) showing
of a sanitary napkin having a second type of structure which allows
a portion of the main body portion of the sanitary napkin to decouple
from the panty covering component.
FIG. 14A is a simplified end view of the sanitary napkin shown
in FIG. 14 after the absorbent element has been compressed.
FIG. 15 is a simplified end view (similar to that of FIG. 11) showing
of a sanitary napkin having a third type of structure which allows
a portion of the main body portion of the sanitary napkin to decouple
from the panty covering component.
FIG. 15A is a simplified end view of the sanitary napkin shown
in FIG. 15 after the absorbent element has been compressed.
FIG. 15B is a simplified end view of a sanitary napkin having flaccid
material that joins the main body portion of the sanitary napkin
to the panty covering component which allows a portion of the main
body portion of the sanitary napkin to decouple from the panty coveting
component.
FIG. 15C is a simplified end view of a sanitary napkin having extensible
material that joins the main body portion of the sanitary napkin
to the panty covering component which allows a portion of the main
body portion of the sanitary napkin to decouple from the panty covering
component.
FIG. 16 is a simplified schematic side view of the procedure used
to measure resistance to edge compression of the side wrapping elements.
FIG. 17 is a plan view of a sanitary napkin having an attachment
mechanism used to join the panty covering component to the main
body portion of the sanitary napkin that comprises a rectangular
zone that is centered about the longitudinal centerline.
FIG. 18 is a plan view of a sanitary napkin having an attachment
mechanism used to join the panty covering component to the main
body portion of the sanitary napkin that comprises two strips that
are oriented in the longitudinal direction.
FIG. 19 is a plan view of a sanitary napkin having an attachment
mechanism used to join the panty covering component to the main
body portion of the sanitary napkin that comprises two strips that
are oriented in the transverse direction.
FIG. 20 is a plan view of a sanitary napkin having an attachment
mechanism used to join the panty covering component to the main
body portion of the sanitary napkin that is in the form of a block
letter "I".
FIG. 21 is a bottom plan view of a panty covering component having
hook-like mechanical fasteners distributed radially on portions
thereof, as shown in place in a section of a panty crotch.
FIG. 22 is a perspective view of a portion of a panty with the
sanitary napkin of the present invention in place therein.
FIG. 23 is a plan view of an alternative embodiment of the panty
covering component of the present invention.
FIG. 24 is a top plan view of a sanitary napkin having a panty
covering component that is generally inextensible with the exception
of zones in the corners of the panty covering component.
FIG. 25 is a schematic cross-sectional view of a sanitary napkin
having its longitudinal side margins folded underneath its main
body portion and attached to a panty covering component.
FIG. 26 is a simplified schematic cross-sectional view of a sanitary
napkin comprised of extensible components in which the backsheet
is an extensible material that extends outward beyond the topsheet
and absorbent core to serve as the panty covering component.
FIG. 27 is a graph showing the "set" of an extensible
material after going through several cycles of elongation.
FIG. 28 is a graph that shows the edge compression of an extensible
material.
DETAILED DESCRIPTION OF THE INVENTION
1. General Characteristics of the Absorbent Article
The overall characteristics of the absorbent article of the present
invention will be discussed first.
FIGS. 1-5 show a preferred embodiment of a disposable absorbent
article of the present invention 20. The present invention relates
to absorbent articles, such as sanitary napkins. More particularly,
the present invention relates to sanitary napkins that have a main
body portion 21 (or "basic sanitary napkin" or "base
sanitary napkin") that comprises the portions of the sanitary
napkin without the undergarment covering component, and an undergarment
covering component ("garment covering component", or "panty
covering component") 100 that preferably stretches with the
wearer's panties and automatically wraps the sides of the wearer's
panties when the wearer places the sanitary napkin in her panties
and pulls her panties up.
The term "absorbent article", as used herein, refers
to articles which absorb and contain body exudates. More specifically,
the term refers to articles which are placed against or in proximity
to the body of the wearer to absorb and contain the various exudates
discharged from the body. The term "absorbent article"
is intended to include sanitary napkins, pantiliners, and incontinence
pads (and other articles worn in the crotch region of a garment).
The term "disposable" refers to articles which are intended
to be discarded after a single use and preferably recycled, composted,
or otherwise disposed of in an environmentally compatible manner.
(That is, they are not intended to be laundered or otherwise restored
or reused as an absorbent article.) In the preferred embodiment
illustrated, the absorbent article is a sanitary napkin designated
20.
The term "sanitary napkin", as used herein, refers to
an article which is worn by females adjacent to the pudendal region
that is intended to absorb and contain the various exudates which
are discharged from the body (e.g., blood, menses, and urine). It
should be understood, however, that the present invention is also
applicable to other feminine hygiene or catamenial pads such as
panty liners, or other absorbent articles such as incontinence pads,
and the like.
The sanitary napkin 20 has two surfaces, a liquid pervious body-contacting
surface or "body surface" 20A and a liquid impervious
garment surface 20B. The sanitary napkin 20 is shown in FIG. 1 as
viewed from its body surface 20A. The body surface 20A is intended
to be worn adjacent to the body of the wearer. The garment surface
20B of the sanitary napkin 20 (shown in FIG. 2) is on the opposite
side and is intended to be placed adjacent to the wearer's undergarments
when the sanitary napkin 20 is worn.
The 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 sanitary napkin 20 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 sanitary napkin
20 is worn. The terms "transverse" or "lateral"
used herein, are interchangeable, and refer to a line, axis or direction
which lies within the plane of the sanitary napkin 20 that is generally
perpendicular to the longitudinal direction.
FIG. 1 shows that the main body portion 21 of the sanitary napkin
20 has two spaced apart longitudinal edges 22, two spaced apart
transverse or end edges (or "ends") 24, and four corners
27, which together form the periphery 26 of the main body portion
of the sanitary napkin 20. The main body portion also has two end
regions, which are designated first end region 28 and second end
region 30. A central region 32 is disposed between the end regions
28 and 30. The end regions 28 and 30 extend outwardly from the edges
of the central region 32 about 1/8 to about 1/3 of the length of
the main body portion. A detailed description of the central region
32 and the two end regions 28 and 30 is contained in U.S. Pat. No.
4,690,680 issued to Higgins on Sep. 1, 1987.
The sanitary napkin 20 (or main body portion thereof) can be of
any thickness, including relatively thick, relatively thin, or even
very thin. The embodiment of the sanitary napkin 20 shown in FIGS.
1-3 of the drawings is intended to be an example of a relatively
thin sanitary napkin, preferably an "ultra-thin" sanitary
napkin. It should be understood, however, when viewing these figures
the number of layers of material shown cause the sanitary napkin
20 to appear much thicker than it actually is. An "ultra-thin"
sanitary napkin 20 as described in U.S. Pat. Nos. 4,950,264 and
5,009,653 issued to Osborn preferably has a caliper of less than
about 3 millimeters. The thin sanitary napkin 20 shown should also
be preferably relatively flexible, so that it is comfortable for
the wearer.
FIG. 2 shows the individual components of the main body portion
21 of the sanitary napkin 20 of the present invention. The main
body portion 20 shown in FIG. 2 generally comprises at least three
primary components. These include a liquid pervious topsheet 38,
a liquid impervious backsheet (or "barrier means") 40,
and an absorbent core 42 positioned between the topsheet 38 and
the backsheet 40. There are occasions, however, when one or more
of these components, such as the backsheet, can be replaced by a
component that serves as part of the undergarment covering component
described below. The main body portion 21 of the sanitary napkin
20 can be comprised of mostly conventional components, and as a
result, be generally inextensible. In preferred embodiments, however,
main body portion of the sanitary napkin is one of those described
in U.S. patent application Ser. Nos. 07/915,133 and 07/915,284 both
filed Jul. 23, 1992, in the name of Osborn, et al. (PCT Publication
Nos. WO 93/01785 and 93/01786 both published Feb. 4, 1993), which
is comprised of one or more extensible components. More preferably,
the main body portion 21 is comprised of all extensible components,
and the sanitary napkin has an overall extensibility.
The sanitary napkin 20 of the present invention also comprises
a panty covering component 100. The panty covering component 100
comprises a pair of side wrapping elements 52 that extend laterally
outward beyond the longitudinal side edges 22 of the main body portion
21 a distance of less than one-half the width of the main body portion
to the distal edges 53 of the side wrapping elements 52. At least
portions of the panty covering component 100 are extensible. The
extensible portions of the panty covering component 100 should generally
be located between the points where the panty covering component
is attached to the main body portion, Q, and the distal edges 53
of the side wrapping elements 52. The side wrapping elements 52
are the portions of the panty covering component 100 that will automatically
fold around the crotch edge portions of the wearer's panties toward
the underside of the panties when the sanitary napkin is placed
in the wearer's panties and the panties are pulled up adjacent the
wearer's body.
The extensibility of the main body portion 21 of the sanitary napkin
20 is shown in a simplified fashion in FIG. 6. The term "extensible",
as used herein, refers to articles that can increase in at least
one of their dimensions in the x-y plane. The x-y plane is a plane
generally parallel to the faces of the sanitary napkin 20. The main
body portion 21 of the sanitary napkin 20 shown in FIG. 6 is preferably
extensible both in length and width. The main body portion 21 of
the sanitary napkin 20, in other embodiments however, may only be
extensible in one of these directions. Preferably, the main body
portion of the sanitary napkin 20 is extensible at least in the
longitudinal direction.
The main body portion 21 of the sanitary napkin 20 may in some
preferred embodiments, in addition to being extensible, also be
stretchable. The term "stretchable", as used herein, refers
to articles that are extensible when stretching forces are applied
to the article and offer some resistance to stretching. More preferably
still, the main body portion 21 of the sanitary napkin 20 may be
elastically stretchable. The terms "elastically stretchable"
or "elastically extensible" are intended to be synonomous.
These terms, as used herein, mean that when the stretching forces
are removed, the main body portion will tend to return toward its
unextended or unstretched (or "original" dimensions).
The main body portion 21 need not return all the way to its unstretched
dimensions, however. It may, as shown in FIG. 6, return to relaxed
dimensions (such as L.sub.R and W.sub.R) between its unstretched
dimensions and extended (or stretched dimensions) L.sub.S and W.sub.S.
Making the main body portion 21 elastically stretchable will reduce
the undesirable tendency of the main body portion to gather longitudinally
inward (i.e., bunch longitudinally) when forces which tend to stretch
the sanitary napkin are removed. This is particularly true when
the wearer's panties contract.
The main body portion of the sanitary napkin is preferably extensible
in the amounts described in PCT Publication Nos. WO 93/01785 and
WO 93/01786. To summarize the same, the main body portion is preferably
capable of extending between about 5% and less than about 50%, more
preferably between about 10% and about 40%, and most preferably
between about 25% and about 40% under the forces associated with
wearing the sanitary napkin in a pair of panties. Preferably, the
main body portion is capable of such extension under forces of between
about 50-100 grams and about 1,000-1,500 grams, more preferably
under forces of between about 250 grams and about 800 grams. FIG.
7 is a table which sets forth some additional ranges of forces for
the extensibility of preferred absorbent articles. It is to be understood
that all of the limits and ranges specified herein include all narrower
ranges, limits, and amounts that are within the specified limits
and ranges. As shown in FIG. 7, the main body portion of the sanitary
napkin can also be provided with a "force wall" to prevent
elongation past a certain amount without substantial increases in
the amount of force applied to the main body portion. If the panty
covering component is provided with an extensible portion that is
fastened to the inside of the wearer's panty crotch, then the panty
covering component is preferably also provided with a force wall
to facilitate removal of the sanitary napkin from the wearer's panties.
The extensible portions of the panty covering component preferably
are extensible in similar amounts, and in response to similar forces,
as the portions of the sanitary napkin comprising the main body
portion. However, any inherent elasticity in the extensible portions
of the panty covering component (that is, any tendency of the extensible
portions to return to their original dimension) is generally relatively
low. The extensible portions are also preferably extensible without
being elasticized or elsaticated (where separate elastic bands are
stretched and attached to the panty covering component in an extensible
condition). These extensible portions of the panty covering component
have a relatively high "set" (compared to the values shown
in FIG. 7) and a low return force so they will wrap around the edges
of the wearer's panties without tending to come unwrapped from the
same.
2. The Individual Components of the Sanitary Napkin and the Assembly
of the Same.
The individual components which may be suitable for the various
embodiments of the sanitary napkin 20 of the present invention will
now be looked at in greater detail with reference to FIGS. 1-3.
A. The Topsheet
The topsheet 38 comprises a first liquid pervious component. When
the sanitary napkin 20 is in use, the topsheet 38 is in close proximity
to the skin of the user. The topsheet 38 is preferably as compliant,
soft feeling, and non-irritating to the user's skin as possible.
The topsheet 38 should further exhibit good strikethrough and a
reduced tendency to rewet, permitting bodily discharges to rapidly
penetrate it and flow toward the core 42, but not allowing such
discharges to flow back through the topsheet 38 to the skin of the
wearer.
The topsheet 38 has two sides (or faces or surfaces), including
a body-facing side 38A and a garment-facing side (or core-facing
side) 38B. The body-facing side 38A of the topsheet 38 generally
forms at least a portion of the body-contacting surface ("body
surface") 20A of the sanitary napkin 20. The topsheet 38 has
two longitudinal edges 38C and two end edges 38D.
(A similar numbering system applies to the other components of
the sanitary napkin. That is, the side of the component facing the
wearer's body can be designated by the number of the component and
a reference letter "A". The side facing the wearer's undergarments
can be designated by the number of the component and the letter
"B". The side and end edges can be designated by the number
of the component and the reference letters "C" and "D",
respectively.)
A suitable topsheet 38 may be manufactured from a wide range of
materials including, but not limited to woven and nonwoven materials,
apertured formed thermoplastic films, apertured plastic films, hydro-formed
films, porous foams, reticulated 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 or modified natural fibers (e.g., polymeric fibers, such
as polyester, polypropylene fibers, and polyethylene, or polyvinylalcohol,
starch base resins, polyurethanes, cellulose esters, nylon, and
rayon fibers) or from a combination of natural and synthetic fibers.
When the topsheet 38 comprises a nonwoven web, the web may be spunbonded,
carded, wet-laid, meltblown, hydroentangled, combinations of the
above, or the like.
Apertured films are generally preferred for the topsheet 38 because
they are pervious to liquids and, if properly apertured, have a
reduced tendency to allow liquids to pass back through and rewet
the wearer's skin. Suitable apertured films are described in U.S.
Pat. No. 3,929,135 issued to Thompson on Dec. 30, 1975, U.S. Pat.
No. 4,324,426 issued to Mullane et al. on Apr. 13, 1982, U.S. Pat.
No. 4,342,314 issued to Radel et al. on Aug. 3, 1982, U.S. Pat.
No. 4,463,045 issued to Ahr, et al. on Jul. 31, 1984, and U.S. Pat.
No. 5,006,394 issued to Baird on Apr. 9, 1991. A particularly suitable
topsheet 38 is made in accordance with U.S. Pat. No. 4,342,314 issued
to Radel and U.S. Pat. No. 4,463,045 issued to Ahr, et al. A topsheet
38 made of model X-3265 or model P1552 apertured formed film sold
by Tredegar Corporation of Terre Haute, Indiana has been found to
work well.
The topsheet 38 can be made extensible by performing a mechanical
operation, such as pleating, corrugating, or ring rolling on the
topsheet material to provide folds in the topsheet that are able
to open when the topsheet is stretched. Such a process can be performed
on many of the topsheet materials described above. In one preferred
embodiment of the present invention, the topsheet 38 is made in
accordance with U.S. Pat. No. 4,463,045 and ring rolled to provide
it with a degree of extensibility. Such a topsheet is described
in U.S. patent application Ser. No. 07/936,195 entitled "Polymeric
Web Having Deformed Sections Which Provide A Substantially Increased
Elasticity To The Web", filed in the name of John J. Curro,
et al. on Aug. 25, 1992.
Suitable processes for ring rolling or "pre-corrugating"
are described in U.S. Pat. No. 4,107,364 issued to Sisson on Aug.
15, 1978, U.S. Pat. No. 4,834,741 issued to Sabee on May 30, 1989
and in co-pending, commonly assigned U.S. patent application Ser.
No. 07/662,536 filed by Gerald M. Weber et al. on Feb. 28, 1991,
U.S. patent application Ser. No. 07/662,537 filed by Kenneth B.
Buell et al. on Feb. 28, 1991, and U.S. patent application Ser.
No. 07/662,543 filed by Gerald M. Weber et al. on Feb. 28, 1991
(collectively referred to herein as the "Ring Rolling"
patent applications).
The fold lines in the corrugations of a ring rolled topsheet should
run in the transverse direction so the topsheet is longitudinally
extensible. In other embodiments, the fold lines could run in the
longitudinal direction, both directions, and/or other directions.
The topsheet 38 will be extensible in directions perpendicular to
the fold lines.
In a preferred embodiment, the topsheet 38 is rendered hydrophilic
so that liquids will transfer through the topsheet 38 faster. This
will diminish the likelihood that body exudates will flow off the
topsheet rather than being drawn through the topsheet and being
absorbed by the absorbent core. The topsheet can be rendered hydrophilic
by treating it with surfactants. Suitable methods of applying surfactants
are described in U.S. Pat. Nos. 4,950,254 and 5,009,653 issued to
Osborn.
In addition, in preferred embodiments, the inner surface 38B of
topsheet 38 is secured in contacting relation with an underlying
absorbent layer. This contacting relationship results in liquid
penetrating topsheet 38 faster. The topsheet 38 may be kept in a
contacting relationship with an underlying layer by bonding the
topsheet to the underlying layer. However, it is not absolutely
necessary to bond the face of the topsheet 38 to the face of the
underlying layer. The topsheet 38 can be maintained in contact with
an underlying absorbent component by applying adhesives between
the topsheet and the underlying component, by entangling the fibers
of the underlying layer with the topsheet, by fusing the topsheet
38 to an underlying absorbent layer by a plurality of discrete individual
fusion bonds, or by any means known in the art.
B. The Absorbent Core
The absorbent core 42 is positioned between the topsheet 38 and
the backsheet 40. The absorbent core 42 provides the means for absorbing
menses and other body fluids.
The absorbent core 42 need not have an absorbent capacity much
greater than the total amount of fluid anticipated to be absorbed.
The absorbent core 42 is generally compressible, conformable, and
non-irritating to the user's skin. It can comprise any material
used in the art for such purpose. Non-limiting examples include
natural materials such as comminuted wood pulp which is generally
referred to as airfelt, creped cellulose wadding, hydrogel-forming
polymer gelling agents, modified cross-linked cellulose fibers (such
as those described in U.S. Pat. No. 5,217,445 issued to Young, et
al. on Jun. 8, 1993, capillary channel fibers (that is, fibers having
intra-fiber capillary channels such as those described in U.S. Pat.
No. 5,200,248 issued to Thompson, et al. on Apr. 6, 1993), absorbent
foams, absorbent sponges, synthetic staple fibers, polymeric fibers,
peat moss, or any equivalent material or combinations of materials.
The polymeric gelling agents listed above may also be referred
to as "absorbent gelling materials" or "superabsorbent
materials". Polymeric gelling agents are those materials which,
upon contact with liquids such as water or other body liquids, imbibe
such liquids and thereby form hydrogels. In this manner, liquids
discharged into the absorbent core 42 can be acquired and held by
the polymeric gelling agent, thereby providing the articles herein
with enhanced absorbent capacity and/or improved liquid retention
performance. The polymeric gelling agent which is employed in the
absorbent core 42 will generally comprise particles 41 of a substantially
water-insoluble, slightly cross-linked, partially neutralized, hydrogel-forming
polymer material. The polymeric gelling agent can be in many forms,
including in the form of pellets, flakes, or fibers.
In one preferred embodiment shown in FIG. 2, the absorbent core
42 is a laminate. The laminate is comprised of a layer of superabsorbent
polymer material, such as in the form of particles 41, disposed
between two air-laid tissues, first and second tissue layers (or
"upper" and "lower" tissue layers) 43 and 47,
respectively. The first and second tissue layers 43 and 47 provide
containment of the superabsorbent polymer material, improve lateral
wicking of the absorbed exudates throughout the absorbent core 42
and provide a degree of absorbency. The tissue layers 43 and 47
can be comprised of a single tissue web which is folded with the
superabsorbent material particles 41 between, or two separate sheets
of the same (or different) tissue.
A suitable laminate is a superabsorbent laminate known as WATER-LOCK
L-535 available from the Grain Processing Corporation of Muscatine,
Iowa (WATER-LOCK registered TM by Grain Processing Corporation).
Such superabsorbent laminates are disclosed in U.S. Pat. No. 4,467,012,
issued to Pedersen et al. on Aug. 21, 1984, U.S. Pat. No. 4,260,443,
issued to Lindsay et al. on Apr. 7, 1981, and U.S. Pat. No. 4,578,068
issued to Kramer, et al. on Mar. 25, 1986. The laminate absorbent
core 42 can be made extensible by cutting or slitting the same.
FIG. 8 shows that the absorbent core 42 is a laminate as described
above which is slitted or partially slitted for longitudinal extensibility.
In alternative embodiments, making the same from tissue paper having
between 20% and 200% stretch (i.e., capable of extending to an extended
dimension that is between about 1.2 and 3 times its unextended dimension).
Such tissue sheets can be made by a number of processes. The tissue
paper may in one embodiment, be conventionally creped tissue. For
example, the tissue paper may be a BOUNTY tissue that is taken directly
after it has been creped off of a Yankee dryer before any crepe
is pulled out of the tissue. A process for making such a tissue
is described in U.S. Pat. No. 5,098,522 issued to Smurkoski, et
al. on Mar. 24, 1992.
In alternative embodiments, a tissue with no or very low initial
crepe can be creped after lamination. The creping process in this
case could occur by passing the laminate through two matched rolls
such that they would yield a corrugated laminate tissue with stretch
in the range of 20% to 200%. The corrugations should be perpendicular
to the direction of desired stretch. In still other embodiments,
the entire main body portion can be creped.
The longitudinal and end edges 22 and 24 of the main body portion
21 are preferably sealed to prevent the wicking and expulsion of
liquid or liquid-containing superabsorbent material from the napkin
when it is extended. Alternatively, the edges 42C and 42D of the
absorbent core 42 may be sealed rather than sealing the edges of
the entire main body portion. The edges of the core 42 may, for
example, be wrapped or covered by a tissue layer. In other alternative
embodiments, the edges of the tissue may be folded, or otherwise
manipulated to prevent the wicking and expulsion of liquid or liquid-containing
superabsorbent material particles 41 from the core 42. All permanent
seals around the perimeter of the main body portion should not break
upon lengthening (i.e., any seal is intended to remain for the duration
of the use of the sanitary napkin.)
The absorbent core 42 may be made elastically extensible even though
it has no elastic properties of its own. The absorbent core 42 can
be made elastically extensible by attaching it to an elastic backsheet
or topsheet so that the absorbent core 42 will extend and retract
with the elastic topsheet or backsheet.
C. The Backsheet
The backsheet 40 prevents the exudates absorbed and contained in
the absorbent core 42 from wetting articles which contact the sanitary
napkin 20 such as pants, pajamas and undergarments. The backsheet
40 is impervious to liquids (e.g., menses and/or urine). The backsheet
40 is preferably manufactured from a thin plastic film, although
other flexible liquid impervious materials may also be used.
The backsheet 40 may 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 40 is a polyethylene film having a thickness
of from about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Exemplary
polyethylene films are manufactured by Clopay Corporation of Cincinnati,
Ohio, under the designation P18-0401 and by Tredegar Film Products
of Terre Haute, Ind., under the designation XP-39385.
The backsheet 40 is preferably embossed and/or matte finished to
provide a more clothlike appearance. Further, the backsheet 40 may
permit vapors to escape from the absorbent core 42 (i.e., the backsheet
40 may be breathable) while still preventing exudates from passing
through the backsheet 40. Flushable or biodegradable backsheets
can also be used, e.g., such as with the pantiliner devices described
herein. Another suitable backsheet material is nonwoven/film laminate
described in U.S. Pat. No. 5,007,906 issued to Osborn Apr. 16, 1991.
The backsheet 40 can be made extensible by performing a mechanical
operation, such as pleating, corrugating, or ring rolling the backsheet
material. Preferably, however, the backsheet 40 is made extensible
by forming it from an elastomeric film such as the film described
in U.S. Pat. No. 4,476,180 issued to Wnuk on Oct. 9, 1984. Such
a film is obtained from Exxon Chemical Company of Lake Zurich, Ill.
as Exxon film EXX-500 (formerly EXX-7).
Another particularly preferred extensible backsheet 40 is an extended
adhesive film Formula #198-338 manufactured by the Findley Adhesives
Company of Wauwatosa, Wisconsin. The Findley adhesive film is a
fluid impervious film capable of extending 200-300%. The Findley
adhesive film is preferred because it is also elastically extensible.
At least one side of this film can be used with the adhesive "as
is" in the sanitary napkin 20. For example, this side of the
adhesive film can be adhered to the garment-facing side 42B of the
absorbent core 42. The other side of the adhesive film that forms
the garment-facing side 40B of the backsheet 40 may have its adhesive
surface at least partially covered (or "blocked" to eliminate
its adhesive characteristics). The adhesive defining the body-facing
side 40A of the backsheet can also be at least partially blocked.
The exposed adhesive can be blocked in a number of suitable ways.
These include, but are not limited to attaching a layer of nonadhesive
material to cover the exposed adhesive, and brushing or sprinkling
a powdered material such as talcum powder or corn starch on at least
part of the exposed adhesive. The partial blocking of the exposed
adhesive on the garment-facing side 40B of the backsheet 40 can
be used with the remaining exposed adhesive to create particular
adhesive patterns for fastening the backsheet to the panty covering
component.
In still other embodiments, an adhesive film can be created with
one side that has adhesive tack, and one side without tack. One
suitable adhesive film having these characteristics is a composite
structure comprising a nonwoven elastomeric film with a low modulus
pressure sensitive adhesive, such as adhesive film Formula #198-338
which is available with a blocking film such as film Formula H2301
from the Findley Adhesives Company. Such materials are further described
(and used for other purposes) in U.S. Pat. No. 5,032,120 issued
to Freeland, et al. on Jul. 16, 1991, and U.S. Pat. No. 5,037,416
issued to Allen, et al. on Aug. 6, 1991.
In other preferred embodiments, the backsheet 40 may comprise an
extensible laminate structure comprised of two or more layers. The
laminate can be comprised of layers which are each capable of different
extensibility. For instance, a backsheet 40 can comprise a laminate
formed of a layer of Findley adhesive film that is covered on one
or both sides by an extensible nonwoven web or by an extensible
film.
D. Combinations of TopSheet, Backsheet, and Core Materials and
Assembly of the Same Into the Main Body Portion of the Sanitary
Napkin.
The main body portion 21 of the sanitary napkin 20 of the present
invention can be comprised of different combinations of the topsheet,
backsheet, and core materials. The main body portion 21 may, as
noted above, be comprised of all extensible components. The main
body portion may also be comprised of any of the other types or
combinations of extensible or inextensible topsheets, backsheets
and absorbent cores that are described in PCT Publication Nos. WO
93/01785 and 93/01786.
The components of the main body portion described above (the topsheet,
backsheet, and absorbent core) can be assembled in any suitable
manner. In the preferred embodiment shown in FIGS. 1-3, the components
of the main body portion are assembled in a "sandwich"
configuration with the components sized so that the edges of the
topsheet 38 and backsheet 40 extend outward beyond the edges of
the absorbent core 42. The topsheet 38 and backsheet 40 are preferably
at least partially peripherally joined using known techniques. As
shown in FIG. 1, the topsheet 38 is preferably secured to backsheet
40 along a first seam, such as seam 90. Seam 90 is preferably liquid
impervious. The seam 90 can be formed by any means commonly used
in the art for this purpose such as by gluing, crimping, or heat-sealing.
The term "joined", as used herein, encompasses configurations
in which an element is directly secured to another element by affixing
the element directly to the other element; configurations in which
the element is indirectly secured to the other element by affixing
the element to intermediate memeber(s) which in turn are affixed
to the other element; and configurations in which one element is
integral with another element, i.e., one element is essentially
part of the other element.
The components of the sanitary napkin 20 can be joined together
by adhesives, stitching, heat and/or pressure bonds, dynamic mechanical
bonds, ultrasonic bonds, intermingling or entanglement of the fibers
or other structural elements comprising the components of the sanitary
napkin, such as by meltblowing the fibers comprising one component
onto another component, extruding one component onto another, or
by any other means known in the art. Suitable means for attaching
the components of the sanitary napkin are described in U.S. patent
application Ser. No. 07/944,764 filed in the name of Cree, et al.
on Sep. 14, 1992.
When the main body portion is comprised of extensible components,
the components can be joined together in any suitable manner that
allows the main body portion to extend. The backsheet 40, in one
example comprises a stretchable adhesive film. The core 42 is placed
on top of the backsheet 40. The topsheet 38 is then placed on top
of the core 42. The portions of the edges of the topsheet 38 that
extend outward beyond those of the core 38 are secured to those
of the backsheet 40 using the adhesive around the perimeter of the
backsheet film. It has been found that such a construction adequately
secures the components of the sanitary napkin without further securing
the faces of the adjacent components to each other. Although, as
noted above, it is often preferred to secure some of the components
at their faces, as well.
The above manners of joining the components are preferred for ease
of construction. (Other means of uniting the various components
can be used.) For instance, the present invention also includes
so-called "tube" products. In these products, a liquid
pervious cover material (such as topsheet material) can be wrapped
completely around the absorbent core and the backsheet, and then
the components can be secured together. In alternative arrangements,
the topsheet could be wrapped around the core, and the wrapped core
could be placed on and secured to the backsheet.
E. The Panty Covering Component.
The panty covering component 100 comprises a pair of side wrapping
elements 52 that are disposed along the longitudinal side edges
of the sanitary napkin to automatically wrap the sides of a wearer's
panties. The panty covering component 100 provides an alternative
to conventional side flaps.
FIGS. 1-5 show a preferred embodiment of the panty covering component.
Before examining the features of the sanitary napkin shown in FIGS.
1-5 in greater detail, the functioning of the panty covering component,
in its most basic forms, will be discussed with relation to FIGS.
9-15C.
FIGS. 9 and 9A are simplified schematic end views of a sanitary
napkin having longitudinally extensible flaps, such as the one described
in U.S. Pat. No. 4,940,462 issued to Salerno. The sanitary napkin
shown in the Salerno patent suffers from several drawbacks due to
the fact that the longitudinally expandable flaps extend directly
outward from the longitudinal sides of the absorbent element. The
expandable flaps in Salerno are attached directly to an inextensible
body. This limits the extensibility of the portions of the Salerno
flaps that are located adjacent to the absorbent element. In order
for the Salerno flaps to extend an amount sufficient to wrap around
the panty elastics, particularly if the panty crotch stretches,
the flaps have to have a relatively wide transverse dimension.
FIG. 9A also shows that any laterally inward compression of the
absorbent portion of the Salerno sanitary napkin will cause the
flaps to be pulled inward. This can result in a loss in the ability
of the flaps to cover a given area of the wearer's panties (i.e.,
a loss in area coverage), and may also cause the flaps to become
detached from the wearer's panties.
FIG. 10 shows a first basic embodiment of the panty covering component
of the present invention. The panty covering component 100 comprises
side wrapping elements 52 that are extensible extensions from the
longitudinal sides of an extensible sanitary napkin. The extensions
are preferably extensions of non-absorbent components. The panty
covering component (or the extensible portions thereof) can, in
this, like most of the other embodiments described herein, be extensible
in the longitudinal direction, the transverse direction, or both.
When the panties are pulled up on the wearer's body, the stretching
of the portions of the panties along the leg elastics causes the
extensions to naturally fold around and wrap the elastic-containing
edges of the panty crotch.
In this particular embodiment, the distal edges 53 of the extensions
preferably extend from about 3/8 inch (about 1 cm) to about 2 inches
(about 5 cm) from the edge of the absorbent core of the sanitary
napkin. The extensible extensions can be comprised of one of the
components of the main body portion, or they can comprise separate
elements joined to the main body portion. In a particularly preferred
version of this embodiment, an adhesive fastener 45 may be applied
up to about 1/8 inch (3 mm) of the edge on the garment-facing side
of the extensions to help hold the extensions in place around the
panty crotch during vigorous motions by the wearer (although such
fasteners are generally not required under normal circumstances).
In alternative versions of this embodiment, the extensions can
be provided with regions that are permanently extensible (that is,
regions that will have no tendency to retract after extension) along
any of those portions of the extension that will be disposed in
the area of the panty elastics. In other alternative versions, extensions
can be folded, gathered, or pinched and sealed to further facilitate
wrapping the elastic-containing edges of the panty crotch. FIG.
26 shows an alternative version of such an embodiment in which the
sanitary napkin is extensible and the backsheet extends beyond the
edges of the topsheet and absorbent core to form the extensible
extensions. In this embodiment, all of the components of the sanitary
napkin are preferably at least extensible in the longitudinal direction.
The fact that the sanitary napkin is extensible at least partially
alleviates some of the problems associated with the Salerno sanitary
napkin. The fact that the side wrapping elements are joined to an
extensible body rather than to an inextensible body, allows the
side wrapping elements to continue to stay wrapped around the sides
of the panty crotch even if the panty crotch stretches.
It should be understood that the "basic" embodiments
described herein are directed to certain features with which the
panty covering component may be provided. These features can be
combined in various different ways (or omitted from) the sanitary
napkin of the present invention. That is, they are not all mandatory
features.
FIGS. 11 and 11A show that in a second basic embodiment, the panty
covering component 100 of the present invention is joined underneath
to the main body portion 21 of the sanitary napkin inboard of the
longitudinal side edges 22 of the main body portion. The panty covering
component is otherwise unnattached to the garment-facing side of
the main body portion 21 of the sanitary napkin 20 between the points
of attachment Q and the longitudinal side edges 22 of the main body
portion. The embodiment shown in FIGS. 11 and 11A allows the panty
covering component 100 to stretch between the points, Q, where the
panty covering component is attached to the main body portion and
the place where the panty elastics will cross the panty covering
component. This allows the panty covering component to mold to and
fold around the wearer's panty.
FIGS. 12 and 12A show that in a third basic embodiment, the panty
covering component can be joined a substantial distance inward of
the longitudinal side edges 22 of the main body portion 21 of the
sanitary napkin 20 so that the point of attachment is located in
the region of the longitudinal centerline, L. The embodiment shown
in FIG. 12 provides the advantage that it reduces the tendency for
the compression of the main body portion (particularly compression
of the absorbent core) to interfere with the operation of the panty
covering component 100. The reduction in the tendency for the compression
of the core to interfere with the operation of the panty covering
component 100 occurs because the panty covering component 100 is
not joined near the sides 22 of the main body portion. This prevents
any forces exerted on the core from directly acting on the panty
covering component. FIG. 12 shows that the absorbent core can be
bunched inward to the points, Q, where the panty covering component
100 is attached to the main body portion without effecting the coverage
of the panty covering component 100. This can be contrasted with
FIG. 9A which shows how the flaps of the Salerno sanitary napkin
will bunch inward in response to such forces.
Several additional matters should be noted with regard to the embodiment
shown in FIG. 12. First, the location where the panty covering component
100 is joined to the garment side 21B of the main body portion 21
is most important in the central region 32 of the main body portion
(or, if the main body portion is asymmetrical, the area of the main
body portion that is intended to be between the wearer's legs) because
this is primarily where any bunching of the main body portion 21
will occur. The central region 32 (shown in FIG. 1) is subject to
bunching because this is in the area of the narrowest portion of
the panty crotch and the narrowest space between the wearer's legs,
when the wearer's legs are brought together. This is particularly
true for the central about 3 inches (7.6 cm) to about 6 inches (15
cm) of the main body portion.
The second matter which should be noted with regard to the embodiment
shown in FIG. 12 is that such an embodiment should preferably be
provided with some type of stabilizing structure in order to prevent
the main body portion 21 of the sanitary napkin 20 from pitching
and rolling around the longitudinal centerline relative to the panty
covering component 100.
The third matter which should be noted with regard to the embodiment
shown in FIG. 12 is the manner in which the side wrapping elements
function differently from the flaps of known sanitary napkins. For
example, sanitary napkins are known which have flaps of various
types attached inboard of the longitudinal sides of an absorbent
component. Examples of such flaps are described in U.S. Pat. No.
4,589,876 issued to Van Tilburg and U.S. Pat. No. 4,900,320 issued
to McCoy. The differences are particularly apparent with regard
to the flaps of the sanitary napkin described in the McCoy patent.
The flaps of the sanitary napkin described in the McCoy patent are
intended to completely encircle the panty crotch and be affixed
to each other. The flaps of the McCoy sanitary napkin are designed
to gather the panty crotch inward. The side wrapping elements 52
of the sanitary napkin of the present invention do not overlap,
nor are they designed to gather the wearer's panties. The side wrapping
elements 52 are intended to adjust to the movements of the panties.
That is, they move with the panties and allow the panties to move,
rather than to constrain the movement of the panties as do the flaps
of the McCoy sanitary napkin.
While attaching the panty covering component inboard of the longitudinal
side edges of the main body portion is beneficial, additional benefits
may be achieved by decoupling the main body portion from the panty
covering component. The decoupling of the main body portion from
the panty covering component refers to the ability of the main body
portion to move away from the panty covering component in the z-direction.
(For a discussion of the concept of decoupling in other contexts,
reference can be made to U.S. Pat. No. 5,007,906 issued to Osborn,
et al. on Apr. 16, 1991 and U.S. patent application Ser. No. 07/605,583
filed in the name of Visscher, et al. on Oct. 29, 1990.) The decoupling
of the main body portion is achieved through a decoupling component
(or "isolation component" or "intermediate component")
102 that is joined at points of juncture to the main body portion
and at points of juncture to the panty covering component with extra
material between the two sets of points. (The points of juncture
may comprise lines, zones, etc., and, as a result, may be referred
to simply as "junctures".)
Three basic examples of structures capable of decoupling are shown
in FIGS. 13-15C (FIGS. 13 and 13A; FIGS. 14 and 14A; and FIGS. 15-15C).
FIGS. 13-15C show that the extra material indirectly joins the panty
covering component to the main body portion 21 of the sanitary napkin.
The isolation component 102 is attached to the main body portion
21 at main body portion attachment points 110, and the isolation
component 102 is attached to the panty covering component 100 at
undergarment covering component attachment points 112. These three
sets of figures show the various different possible relationships
between the location of the main body portion attachments points
and the undergarment covering component attachment points.
FIGS. 13 and 13A show a first example in which the sanitary napkin
is provided with a construction that allows the main body portion
21 of the sanitary napkin to decouple from the panty covering component
100. A basic way of accomplishing this is for the decoupling component
102 to comprise a single piece of material or separate strips of
material that form a pair of legs 107 that join the undergarment
covering component 100 to the main body portion 102. The sanitary
napkin shown in FIGS. 13 and 13A is characterized by the fact that
the points of juncture 110 where the decoupling component 102 is
joined to the main body portion 21 are inboard (i.e., closer to
the longitudinal centerline) of the points where the decoupling
component is joined to the panty covering component 100. The construction
shown in FIG. 13A allows the main body portion 21 of the sanitary
napkin to maintain close contact with the wearer's body and the
panty covering component 100 to stay in the wearer's panties even
when the panties move away from the wearer's body. The basic way
of achieving the construction described above can be carried out
in numerous different manners.
For example, in the embodiment shown in FIGS. 13 and 13A, the sanitary
napkin 20 can be provided with a panty covering component 100 that
is in the form of a two layer laminate structure, comprising an
upper layer 106 and a lower layer 108. In this embodiment, the layers
of the laminate are bonded at points of attachment 112 located toward
the longitudinal sides of the laminate. The layers of the laminate
are unbonded between the points of attachment. This allows the unbonded
portion 109 of the upper layer 106 of the laminate (and the overlying
main body portion 21 of the sanitary napkin) to separate from the
lower layer 108 of the laminate and the panty crotch. The structure
shown in FIGS. 13 and 13A provides the lateral stability needed
to the embodiment shown in FIG. 12. In addition, the upper layer
can be provided with transverse extensibility to reduce the tendency
for the compression of the core to pull the sides of the panty covering
component inward.
While the construction of the sanitary napkin is shown in FIG.
13 is suitable for allowing the main body portion to decouple from
the panty covering component, as shown in FIG. 13A, a degree of
bunching of the main body portion could still lead to some tendency
for the side wrapping elements to be pulled inward. The embodiment
shown in FIGS. 13 and 13A, however, is still believed to represent
an improvement over the Salerno sanitary napkin in this regard.
FIGS. 14 and 14A show a second example of a decoupling feature.
In this second example, the sanitary napkin 20 is provided with
extra material in the form of a pair of inwardly attached legs 107
that join the panty covering component 100 to the main body portion
21. (That is, the points where the decoupling component are joined
to the main body portion are outboard of the points where the decoupling
component is joined to the panty covering component.) The inwardly
attached legs may comprise a number of possible types of structures.
For instance, as shown in FIG. 25, the inwardly attached legs can
comprise a portion of one or more of the components of the sanitary
napkin which is/are pleated and folded under the main body portion
of the sanitary napkin and attached to the panty covering component.
Alternatively, the inwardly attached legs can comprise separate
elements that are connected to the main body portion of the sanitary
napkin and the panty covering component. The embodiment shown in
FIGS. 14 and 14A provide the advantage that the panty covering component
is not subject to being pulled inward by compression of the core
and the legs provided the main body portion with stability from
pitching and rolling relative to the main body portion.
FIGS. 15 through 15C show a third example in which a sanitary napkin
is provided with a construction that allows the main body portion
of the sanitary napkin to decouple from the panty covering component.
The panty covering component shown in FIGS. 15 and 15A has pleated
slack material between the main body portion and the panty covering
component. This sanitary napkin combines the features of the embodiments
shown in FIGS. 13 and 14. This panty covering component can be thought
of as having legs with a lower portion like that shown in FIG. 13
and an upper portion like that shown in FIG. 14. The lower portion
of the connecting structure between the main body portion 21 and
the panty covering component 100 helps prevent the compression of
the main body portion 21 from interfering with the molding of the
panty covering component 100 to the wearer's panties. The upper
portion of the connecting structure allows the main body portion
to be bunched or molded to the wearer's body (e.g., to assume a
"W"-shape) without causing the panty covering component
100 to be pulled inward resulting in losing coverage of the panty
covering component.
FIGS. 15B and C show two additional versions of the type of extra
material that joins the main body portion to the panty covering
component. FIG. 15B shows a version having material in the form
of flaccid (or slack) material joining the main body portion to
the panty covering component. FIG. 15C shows a version having extensible
material between the main body portion and the panty covering component.
The panty covering component features shown in FIGS. 15 through
15C are particularly desirable for products having thicker (e.g.,
greater than about 8 mm thick) main body portions. When the sides
of the main body portion of the sanitary napkin are not constrained
as they are in FIG. 14, they are able to move to fit up close to
the wearer's body.
The decoupling component 102 has been described above in terms
of how it can interact to allow the main body portion 21 of the
sanitary napkin to separate from the panty covering component in
the z-direction. The decoupling component can also enhance the functioning
of embodiments in which the panty covering component is joined to
an inextensible main body portion. In these cases, the decoupling
component is preferably provided with extensibility under the same
or lesser forces than those that cause the panty covering component
to extend. The decoupling component is, thus, able to serve as a
stretch isolation component (or "isolation component")
to allow the panty covering component 100 to extend more independently
of the inextensible (or less extensible) components of the main
body portion.
With the fundamental concepts and structures of the panty covering
component described above in mind, the preferred embodiment shown
in FIGS. 1-5 will now be discussed in greater detail. The sanitary
napkin shown in FIGS. 1-5 comprises a panty covering component that
comprises at least one sheet of extensible material 100 which is
used in conjunction with an isolation element 102.
The sheet of extensible material 100 shown in FIGS. 1-5 comprises
a racetrack-shaped sheet of material that is larger in dimensions
than the main body portion of the sanitary napkin. The panty covering
component 100 may be of any suitable size and shape. For example,
the panty covering component 100 may have certain dimensions that
are less than or equal to those of the main body portion of the
sanitary napkin. The panty covering component may be oval, rectangular,
irregular, or some other suitable shape.
FIG. 1 shows that portions of the sheet of extensible material
100 extend laterally outward beyond portions of the longitudinal
edges 22 of the main body portion 21 of the sanitary napkin 20 in
the central region 32 of the sanitary napkin 20. The portions of
the sheet of extensible material 100 that extend laterally outward
beyond the longitudinal edges 22 of the sanitary napkin 20 in the
central region 32 provide side wrapping elements 52 that can be
folded around the edges of the wearer's panties.
It should be understood, however, that while the panty covering
component 100 is shown as being a single sheet of material having
portions which define the side wrapping elements 52, other embodiments
are also within the scope of the present invention. For instance,
in alternative embodiments, the side wrapping elements 52 may each
comprise one or more separate pieces attached to the main body portion
21 of the sanitary napkin. In still other alternative embodiments,
the side wrapping elements 52 may be integral portions of one or
more components of the main body portion. In addition, while the
side wrapping elements 52 are shown as extending from each longitudinal
edge of the main body portion, there may only be one side wrapping
element extending from one of the edges of the main body portion.
Further, the side wrapping elements are preferably mirror images
of each other, and are symmetrical about the longitudinal centerline.
However, it should be understood that the shape and location of
the side wrapping elements described herein are those of a preferred
embodiment, and other embodiments are also possible. For instance,
the side wrapping elements 52 may be offset along the longitudinal
centerline more towards one end edge of the main body portion than
the other.
In the embodiment shown in FIGS. 1-5, the sheet of extensible material
100 is preferably at least extensible in the longitudinal direction.
The sheet of extensible material 100 (or any of the other panty
covering components or components of the sanitary napkin described
herein) can, however, be extensible only in the transverse direction,
or extensible only in a direction between the longitudinal and transverse
directions, or be provided with bi-directional, or multi-directional
extensibility.
The sheet of extensible material 100 can be made of any suitable
material. In one non-limiting example, the sheet of extensible material
100 comprises a laminate. The laminate comprises a sheet of extensible
film such as Findley Adhesive 198-338 secured between two longitudinally
extensible nonwoven webs. In another embodiment, the sheet of extensible
material 100 can comprise an adhesive film secured between extensible
nonwoven webs or between ring rolled plastic film sheets such as
those of a type that can be used for the backsheet.
The side wrapping elements 52 are smaller than conventional flaps.
(That is, the side wrapping elements do not have as great a span
from distal edge to distal edge.) Preferably, the size of the side
wrapping elements relates to the size of the crotch region of the
wearer's panties. Panties have crotch widths that average about
65-70 mm (about 23/4 inches) measured at the narrowest point of
the crotch. Panties come in a wide variety of sizes, however. The
width of panty crotches can range from about 2 inches (about 5 cm)
to about 41/2 inches (about 11.4 cm). The smallest span of conventional
flaps is believed to be about 5 inches (about 12.7 cm) for small
tab-like flaps that are on some current products.
With these factors in mind, the width of the side wrapping elements
should not be large enough to overlap when they fold under the wearer's
panties. The dimensions of the side wrapping elements can be expressed
in terms related to the boundaries of main body portion of the sanitary
napkin. For instance, the span of the side wrapping elements 52
can be expressed in terms of the perpendicular distance in the x-y
plane, D.sub.1, from the most inward point on the longitudinal side
edge of the main body portion (i.e., the point closest to the longitudinal
centerline) R to the distal edge 53 of the side wrapping elements
52. The side wrapping elements 52 preferably extend a distance that
is less than or equal to about 11/4 inch (about 3 cm) from the most
inward portion of the main body portion of the sanitary napkin.
More preferably, the side wrapping elements extend less than or
equal to the following distances from the most inward point on the
main body portion: about 1 inch (about 2.5 cm), about 3/4 inch (about
2 cm), about 1.5 cm, and about 0.5 inch (about 1.25 cm).
The span of the side wrapping elements 52 can alternatively be
specified in absolute terms of the distance from the distal edge
to distal edge when the side wrapping elements 52 are extended laterally
in opposite directions. Expressed in this manner, the span of the
side wrapping elements from one distal edge to the other (and, thus
also the span of the panty covering component) is preferably less
than about 5 inches (about 12.7 cm) more preferably less than or
equal to about 43/4 inches (about 12 cm). The minimum span of the
side wrapping elements should be greater than or equal to any of
the following amounts provided the span is also greater than the
width of the panty crotch: about 21/2 inches (about 6.4 cm); about
3 inches (about 7.6 or 8 cm); or about 31/2 inches (about 9 cm).
A preferred range for the span of the side wrapping elements is
between about 31/2 inches to about 43/4 inches. Even more preferably,
the side wrapping elements have a span of between about 4 inches
(about 10 cm) to about 41/2 inches (about 11.5 cm).
The side wrapping elements 52 can have a length (longitudinal dimension)
that varies within a large range. The length of the side wrapping
elements 52 is preferably at least as large as the longitudinal
dimension of known types of flaps (such as those described in the
Background of the Invention) that attach to each other or to the
underside of a wearer's panties. The side wrapping elements, therefore,
can extend primarily from the central region of the main body portion
of the sanitary napkin. Alternatively, the side wrapping elements
can have a length that is as long as, or longer than, the length
of the main body portion. Providing the sanitary napkin with side
wrapping elements that are shorter than the length of the main body
portion, however, may be preferred from a cost standpoint since
such a sanitary napkin will require less material to make.
The panty covering component 100 should have additional features
in order to automatically wrap the edges of the wearer's panties
and stay in place around the same. For example, at least portions
of the sheet of extensible material 100 preferably comprise a material
having a low return force and a high set. These are materials that,
when stretched, will not tend to return all the way to their unstretched
dimensions. They will tend to remain (or set) close to their extended
dimensions.
When the side wrapping elements 52 comprise a material having a
high set, they will stretch to fit around the crotch of the wearer's
panties. The high set reduces the tendency of the side wrapping
elements 52 to retract and bunch the wearer's panties, or to unfold
from the underneath the panties.
The term "set", as used herein, refers to the amount
of permanent deformation (as a percentage of the original sample
length) remaining in a sample after application and removal of the
indicated strain. The procedure and equipment are described in the
following. (Unless otherwise specified |